Sil-Pad K-4 Datasheet

Bergquist

View All Related Products | Download PDF Datasheet

Datasheet

ThermalClad
®
SELECTION GUIDE
Thermal Solutions
For Surface Mount
Power Applications
TCDG_Cover_09.09.qxp 9/8/2009 1:43 PM Page 3
All statements, technical information and recommendations herein are based on tests we believe to be reliable, and
THE FOLLOWING IS MADE IN LIEU OF ALL WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING THE
IMPLIED WARRANTIES OF MARKETABILITY AND FITNESS FOR PURPOSE. Sellers' and manufacturers'
only obligation shall be to replace such quantity of the product proved to be defective. Before using, user shall deter-
mine the suitability of the product for its intended use, and the user assumes all risks and liability whatsoever in con-
nection therewith. NEITHER SELLER NOR MANUFACTURER SHALL BE LIABLE EITHER IN TORT OR IN
CONTRACT FOR ANY LOSS OR DAMAGE, DIRECT, INCIDENTAL, OR CONSEQUENTIAL, INCLUDING
LOSS OF PROFITS OR REVENUE ARISING OUT OF THE USE OR THE INABILITY TO USE A PRODUCT.
No statement, purchase order or recommendations by seller or purchaser not contained herein shall have any force or
effect unless in an agreement signed by the officers of the seller and manufacturer.
September 2009 Thermal Clad®: U.S. Patent 4,810,563 and others.
ISO-9001:2000
Certificate Number,
QSR-572
TCDG_Cover_09.09.qxp 9/8/2009 1:43 PM Page 4
1
Table of Contents
Thermal Clad
Thermal Clad Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Thermal Clad Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Thermal Clad Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Dielectrics
Selecting Dielectric Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-7
Dielectric Performance Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Summary Of Key Dielectric Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Using Dielectric Materials In Specialty Applications . . . . . . . . . . . . . . . . . . . . . . . .10-11
Design Considerations
Selecting The Base Metal Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12-13
Selecting A Circuit Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14-15
Electrical Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-17
Assembly Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18-19
Other Bergquist Thermal Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20-21
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Thermal Clad Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
(66)Thru-hole FETs (15 )High profile capacitors (9)High profile bus bars
Total Weight 3.4 lbs (1543.6g)
(48)FETs (9)Low profile capacitors (5)Low profile bus bars
Total Weight 0.82 lbs (370.6g)
Thermal Clad is a complete thermal management system, unlike
traditional technology which uses heat sinks, clips and other
mounting hardware.Thermal Clad enables low-cost production
by eliminating the need for costly manual assembly.
2
Key Benefits Of Thermal Clad
The Bergquist Company is the world leader in the develop-
ment and manufacture of thermally conductive interface mate-
rials.Thermal Clad Insulated Metal Substrate (IMS®) was devel-
oped by Bergquist as a thermal management solution for
today’s higher watt-density surface mount applications where
heat issues are a major concern.
Thermal Clad substrates minimize thermal impedance and
conduct heat more effectively and efficiently than standard
printed wiring boards (PWB's). These substrates are more
mechanically robust than thick-film ceramics and direct bond
copper constructions that are often used in these applications.
Thermal Clad is a cost-effective solution which can eliminate
components, allow for simplified designs, smaller devices and an
overall less complicated production processes. Additional ben-
efits of Thermal Clad include lower operating temperatures,
longer component life and increased durability.
Bergquist Thermal Clad substrates are not limited to use with
metal base layers. In one example, power conversion applica-
tions can enhance their performance by replacing FR-4 with
Thermal Clad dielectrics in multi-layer assemblies. In this appli-
cation, the thickness of the copper circuit layer can be mini-
mized by the high thermal performance of Thermal Clad. For
additional information on this topic, refer to the “Specialty
Applications” section on pages 10-11 of this guide.
Thermal Clad®Overview
Cooling with Thermal Clad can
eliminate the need for heat sinks, device
clips, cooling fans and other hardware.
An automated assembly method will
reduce long term costs.
Traditionally, cooling an FR-4 board
required use of a large heat sink, interface
material and various hardware (brackets,
screws or clamps); a configuration requiring
labor intensive manual assembly.
Conventional methods
measured junction temperature
5W=Tj 43ºC
Thermal Clad
measured junction temperature
5W=Tj 35ºC
®
Thermal Clad Benefits
• RoHS compliant and halogen-free
• Lower component operating temperatures
• Reduce printed circuit board size
• Increase power density
• Extend the life of dies
• Reduce the number of interconnects
• Improve product thermal and mechanical performance
• Combine power and control
• Improve product durability
• Enable better use of surface mount technology
• Reduce heat sinks and other mounting hardware, including
thermal interface material
• Replace fragile ceramic substrates with greater
mechanical durability
• Bergquist is your one-stop source from raw materials
to finished circuit
Original Power Board Assembly (Actual)
New Power Board Assembly (Actual)
3
Improve Durability and Performance
Thermal Clad improves durability because designs can be kept
simple while components are kept cool. The low thermal
impedance of the Thermal Clad dielectric outperforms other
insulators for power components, allowing for cooler operation.
Thermal Clad keeps assemblies cool by eliminating thermal
interfaces and using thermally efficient solder joints. Voltage
breakdown and thermal performance improve in potted assem-
blies using SMD’s and bare die on Thermal Clad.
Thermal Clad can also reduce production costs by enabling
automated pick-and-place equipment for SMD’s.
Reduce Board Size and Replace Hardware
Thermal Clad greatly reduces board space while replacing other
components including heat sinks. It offers the opportunity to
eliminate mica and grease or rubber insulators under power
devices by using direct solder mount to Thermal Clad. By elimi-
nating this hardware, heat transfer is improved.
Interconnects can be eliminated by using etched traces on the
Thermal Clad board. In fact, whole sections of PWB’s are often
eliminated. It permits the use of surface mount power and
passive devices to reduce real estate.With Thermal Clad, many
discrete devices can be replaced at the board level.
Dielectric Layer
Base Layer
Bergquist’s manufacturing facility located in Prescott, Wisconsin features state-of-the-art
process capabilities. Process manufacturing uses the latest in technology including
environmental clean room control, surface finishing, coating and lamination.
The Anatomy Of A Thermal Clad Board
Thermal Clad is a dielectric (ceramic-polymer blend) coated metal
base with a bonded copper circuit layer.This unique material offers
superior heat transfer to help cool components while eliminating
the problems associated with fragile ceramics. Different than others,
Bergquist doesn’t use fiberglass, allowing for better thermal perfor-
mance.
Thermal Clad is a three layer system comprised of the following:
t
Circuit Layer: This is the printed circuit foil with a thickness of
1oz. to 10oz. (35-350µm) in standard Thermal Clad.
t
Dielectric Layer: This offers electrical isolation with mini-
mum thermal resistance. Glass carriers degrade thermal perfor-
mance which is why our dielectrics are glass-free. CML is the one
exception because of its prepreg form, a glass carrier is needed
for handling purposes.The dielectric layer is the key element of
Thermal Clad, and bonds the base metal and circuit metal
together. The dielectric has U.L. recognition, simplifying agency
acceptance of final assemblies.
t
Base Layer: This is often aluminum, but other metals such as
copper may also be used.The most widely used base material
thickness is 0.062" (1.57mm) in aluminum, although many thick-
nesses are available. In some applications, the base layer of metal
may not be needed. See “Specialty Applications” on page 11.
Circuit Layer
4
Power Conversion
Due to the size constraints and watt-density
requirements in DC-DC conversion,Thermal
Clad has become the favored choice.Thermal
Clad is available in a variety of thermal perfor-
mances, is compatible with mechanical fasten-
ers and is highly reliable. It can be used in
almost every form-factor and fabricated in a
wide variety of substrate metals, thicknesses
and copper foil weights.
Motor Drives
Compact high-reliability motor drives built on
Thermal Clad have set the benchmark for
watt-density. Dielectric choices provide the
electrical isolation necessary to meet operat-
ing parameters and safety agency test require-
ments. With the ability to fabricate in a wide
variety of form-factors, implementation into
either compact or integrated motor drives is
realized. The availability of Thermal Clad HT
makes high temperature operation possible.
Heat-Rail And Forming
The use of Thermal Clad in heat-rail applica-
tions has increased significantly and is current-
ly used in automotive, audio, motor control
and power conversion applications. Thermal
Clad offers many advantages including surface
mount assembly, attachment capabilities and
excellent thermal performance.The dielectric
can be selectively removed and the metal can
be formed with three-dimensional features
making Thermal Clad a versatile substrate.
LEDs
In Power LED applications, light output and
long life are directly attributable to how well
the LED’s are managed thermally. Thermal
Clad is an excellent solution for designers.
Because T-Clad is a metal based material, it
can be configured for special shapes, bends
and thicknesses thus allowing the designer to
put LED light engines in virtually any applica-
tion. Mounting Power LED’s on T-Clad assures
the lowest possible operating temperatures
and maximum brightness, color and life.
Solid State Relays/Switches
The implementation of Solid State Relays in
many control applications calls for thermally
efficient, and mechanically robust substrates.
Thermal Clad offers both. The material con-
struction allows mounting configurations not
reasonably possible with ceramic substrates.
New dielectrics meet the high thermal per-
formance expectations and can even out-per-
form existing ceramic based designs.
Want to maximize the lifecycle and
color consistency of your LEDs?
This LED-specific solutions guide addresses
important factors and recommendations for
selecting a thermal management solution
ideal for your LED design.
Thermal Clad Applications
Dynamic Mechanical Analysis (DMA) – Measures the
modulus of materials over a range of temperatures. Chamber Ovens – Over 3000 cubic feet (85 cubic meters)
of oven capacity is dedicated to long term thermal bias age
testing. The ovens take material to temperatures above Tg.
At selected intervals, samples are removed and tested to
verify material integrity.
Thermogravimetric Analyzer (TGA) – Measures the stability
of our dielectrics at high temperatures, baking the materials
at prescribed temperatures and measuring weight loss.
Typical Qualification Programs
Insulation Impedance
Temp/Hum/Bias
85C/85%RH/100V
2000 hours
Permittivity/Dissipation
Temp/Hum/Bias
85°C/85%RH/100V
2000 hours
Thermal Shock
Sand Bath
300°C/1 minute and
200°C/72 hour post
Ten Cycle
Solder Shock
Breakdown Voltage
DC and AC
Sequential Aging
Peel Adhesion
Pull Strength
Sequential Aging
Thermal Bias Aging
125°C/100V/2000h Thermal Bias Aging
125°C/100V/2000h Thermal
Conductivity Flammability
Thermal Stress
230°C/10 min.
Thermal Stress
230°C/10 min.
Thermal Bias Aging
175°C/100V/2000h Thermal Bias Aging
175°C/100V/2000h
Temp Cycling
500 cycles/-40°C-150°C
350 hours
Temp Cycling
500 cycles/-40°C-150°C
350 hours
Temp/Hum/Bias
85°C/85%RH/100V
2000 hours
Temp/Hum/Bias
85°C/85%RH/100V
2000 hours
Chemical Soak
Loncoterge - 15 min.
Alcohol - 15 min.
Chemical Soak
Loncoterge - 15 min.
Alcohol - 15 min.
Thermal Bias Aging
125°C/480V/2000h Thermal Bias Aging
125°C/480V/2000h
Thermal Aging
125°C/2000 hours
Thermal Aging
125°C/2000 hours
Electrical
Properties Other Properties
Evaluated
Physical
Properties
Thermal Clad Long Term Reliability
New materials undergo a rigorous 12 to 18 month qualification pro-
gram prior to being released to the market.
In state-of-the-art laboratories and test facilities, Bergquist performs
extensive testing on all their thermal materials for electrical integrity.
Bergquist utilizes stringent development procedures.The lab facilities at
Bergquist are U.L. certified and manufacturing facilities are ISO
9001:2000 certified.
Extensive qualification testing consists of mechanical property valida-
tion, adhesion, temperature cycling, thermal and electrical stress. To
validate long term reliability, electrical testing is performed at selected
intervals to 2000 hours where final evaluation is completed.
To ensure consistent product performance with manufactured materi-
als, we couple the up-front qualification test with regular audits. Audits
include physical, electrical and thermal property tests.
5
Thermal Clad Reliability
Selecting Dielectric Materials
Dielectric Layer
The technology of Thermal Clad resides in the dielectric layer. It is the
key element for optimizing performance in your application.The dielec-
tric is a proprietary polymer/ceramic blend that gives Thermal Clad its
excellent electrical isolation properties and low thermal impedance.
The polymer is chosen for its electrical isolation properties, ability
to resist thermal aging and high bond strengths. The ceramic filler
enhances thermal conductivity and maintains high dielectric strength.
The result is a layer of isolation which can maintain these properties
even at 0.003" (76µm) thickness. See high power lighting applications
for thinner dielectric information. This guide will help you select the
best dielectric to suit your needs for watt-density, electrical isolation
and operating temperature environment.
Standardized Methods For
Measuring Thermal Conductivity
There are several different test methods for determining a material’s
thermal conductivity value. Results can be different depending on the
method chosen, so it is important to use similar test methods in
material comparisons. See chart at right.
Standard test methods include ASTM D5470 and ASTM E1461.
ASTM D5470 is a steady state method and is referred to as the
guarded hot plate.This method provides an analytically derived value
and does not use approximations.ASTM E1461 is a transient method
referred to as Laser Flash Diffusivity. In E1461, thermal diffusivity is the
test output and thermal conductivity is calculated.
Non-Standard In-House Test Methods
The adjacent chart shows how vastly different thermal conductivity
values can be achieved by using “in-house” or non-standard test
methods. For example, when the same dielectric is chosen we can
derive a completely different and much higher thermal conductivity
value by testing a stack-up or laminate with base layer.We can modify
the test further by using different materials for the substrate to obtain
even higher results.Although thermal conductivity values are still rela-
tive to one another so a comparison can be made, these test meth-
ods do not give us an accurate depiction of true thermal perfor-
mance in the application. Included in the chart is a modeled value for
thermal conductivity, a respected model for predicting the effective
thermal conductivity of anisotropic particulate composites, but not
helpful for determining thermal performance in application. We
emphasize using standard test methods such as ASTM D5470 and
ASTM E1461, which are universally accepted and repeatable.
Note: The hot disk method is not a method we use for comparison
because typically this method measures the conductivity of the dielectric
alone, which neglects thermal interfacial resistance between layers and
carrier holding the dielectric. These values must be understood in order to
calculate the actual thermal impedance or thermal performance data.
See section regarding thermal impedance on page 7.
Lower
Thermal Performance
Higher
Thermal Performance
CML
Circuit
Material
Laminate
MP
Multi-Purpose HT
High Temperature HPL
High Power
Lighting
Non-Standard Thermal Conductivity Test
Methods and Model (W/m-K)
Part
Number
Model1Guarded
Hot Plate
Laminate2
Guarded
Hot Plate
Laminate3
Laser Flash
Laminate2Laser Flash
Laminate3
HT-04503 9.0 32.2 36.4 67.6 115
HT-07006 9.0 21.5 23.3 46.0 86.5
MP-06503 4.5 14.0 24.0 34.9 102
Method
Description
1 - Bruggeman Model
2 - Tested with 0.062" (1.57mm) 5052 aluminum substrate
and 2 oz. (70µm) copper foil
3 - Tested with 0.062"(1.57mm) 1100 copper substrate
and 2 oz. (70µm) foil
6
Thermal Conductivity
Thermal conductivity is relevant to the application’s thermal performance
when the thickness of the dielectric material, interfacial resistance and area
are taken into consideration. See “Thermal Impedance” section for more
information, as this data will be the most relevant to your application.
Standardized
Test Methods (W/m-K)
Part
Number
ASTM
D54701ASTM
E14612
HT-04503 2.2 1.97
HT-07006 2.2 1.97
MP-06503 1.3 1.17
Method
Description
1 - ASTM D5470
Guarded Hot Plate
2 - ASTM E1461
Laser Flash Diffusivity
7
Selecting Dielectric Materials
Dielectric Thickness Inches (µm )
.012"
(305)
.010"
(254)
.006"
(152) .008"
(203)
.002"
(51) .004"
(102)
Dielectric Thickness Inches (µm)
.011"
(279)
.007"
(178) .009"
(229)
.003"
(76) .005"
(127)
Lower Thermal Impedance = Lower JunctionTemperatures
TOTAL IMPEDANCE =Sample Thickness + Interfacial Resistance
Thermal Conductivity
Electrical Isolation - Power Applications
Dielectrics are available in thicknesses from 0.003" (76µm) to 0.009"
(229µm), depending on your isolation needs. See “Electrical Design
Considerations” on pages 16-17 to help determine which thickness is
appropriate for your application.
Thermal Impedance Determines Watt Density
Thermal impedance is the only measurement that matters in
determining the watt density capability of your application because
it measures the temperature drop across the stack-up for each watt
of heat flow. Lower thermal impedance results in lower junction tem-
peratures.The lower the thermal impedance, the more efficiently heat
travels out of the components.
Breakdown Voltage In Oil with 2" (51mm) Probe
ASTM D149
Dielectric Thickness Inches (µm)
.002"
(51) .004"
(102) .006"
(152) .008"
(203) .010"
(254) .012"
(305)
1.7
1.2
0.7
0.2
MP
HT
CML
HPL
Dielectric Thickness Inches (µm)
.012"
(305)
.010"
(254)
.006"
(152) .008"
(203)
.002"
(51) .004"
(102)
.000"
(0) .014"
(357)
High Power Lighting Applications
HPL is a dielectric specifically formulated for high power lighting LED
applications with demanding thermal performance requirements.This
thin dielectric at 0.0015" (38µm) has an ability to withstand high tem-
peratures with a glass transition of 185°C and phenomenal thermal
performance of 0.30°C/W. For detailed information, call Bergquist
Sales or go online.
8
Dielectric StabilityCoefficient of Thermal Expansion
Fractional Dimension Change [µm/m°C]
Permittivity with 3" (76mm) Cu Electrode
Measured at 12 Hz after
1000 Hours at 125°C/480V
This chart graphs the stability of the bond strength between the dielectric and the circuit layer
during temperature rise. Although bond strength goes down at higher temperatures, it main-
tains at least 3 lbs/inch (0.53 N/mm) even at 175°C.
ThermoMechanical Analysis (TMA) measures the dimensional stability of materials during
temperature changes, monitoring the Coefficient of Thermal Expansion (CTE). Note: In the
application, the CTE of the base material is a dominant contributor to thermal
mechanical stress. See pages 12-13 for base layer selection.
CTE OF IMS BOARDS - The concerns in exceeding Tgin standard FR-4 materials from a
mechanical standpoint should be tempered when using Thermal Clad. The ceramic filler in
the polymer matrix of Thermal Clad dielectrics results in considerably lower Z-axis expansion
than in traditional FR-4 materials, while the low thickness of the dielectric means significantly
less strain on plated-through-hole (PTH) connections due to expansion.
This chart depicts the storage modulus of the material over a temperature range. All of
our dielectrics are robust, but you will want to choose the one that best suits your operating
temperature environment. See “Assembly Recommendations” on pages 18-19 for additional
information.
This charts depicts the stability of the dielectric electrical properties over a range of
temperatures. The flatter the line, the more stable. Note the stability of our high
temperature dielectric, HT to a temperature of 175°C.
Peel Strength Storage Modulus
Operating Thermal Clad Materials Above Tg
Above the Tgof the material, mechanical and electrical properties
begin to change. Mechanical changes of note are a reduction of peel
strength of the copper foil, an increase in the CTE, and decreasing
storage modulus.There is a potential benefit of relieving residual stress
on the dielectric interfaces, in solder joints and other interconnects
due to CTE mismatches by choosing a dielectric with Tgbelow the
operating temperature. The dielectric material above Tgis in its elas-
tomeric state (much lower storage modulus), allowing some of the
stresses to relax. Changes in electrical properties must also be consid-
ered in operation above Tg, although they are typically only important
at frequencies above1MHz. Effects to consider are changes in the per-
mitivity, dielectric loss and breakdown strength of the material.
Important Note: Many Thermal Clad products have U.L. rating up to
45% higher than their glass transition temperature and are used
extensively in applications above rated Tg.
Dielectric Performance Considerations
9
SINGLE LAYER THERMAL PERFORMANCE DIELECTRIC PERFORMANCE OTHER
Part
Number Thickness1
[.000"/µm] Impedance2
[
°
C/W]
Impedance3
[
°
C in2/W] /
[
°
C cm2/W]
Conductivity4
[W/m-K] Breakdown5
[kVAC]
Permittivity6
[Dielectric
Constant]
Glass
Transition7
[°C]
U.L.
Index8
[°C]
Peel
Strength9
[lb/in] / [N/mm]
HT-04503 3/76 0.45 0.05 / 0.32 2.2 6.0 7 150 140/140 6 / 1.1
HT-07006 6/152 0.70 0.11/ 0.71 2.2 11.0 7 150 140/140 6 / 1.1
MP-06503 3/76 0.65 0.09 / 0.58 1.3 8.5 6 90 130/140 9 / 1.6
MULTI-LAYER
HT-09009 9/229 0.90 0.16 / 1.03 2.2 20.0 7 150 150/150 6 / 1.1
HT-07006 6/152 0.70 0.11/ 0.71 2.2 11.0 7 150 140/140 6 / 1.1
CML-11006*6/152 1.10 0.21 / 1.35 1.1 10.0 7 90 130/130 10 / 1.8
HIGH POWER LIGHTING
HPL-03015 1.5/38 0.30 0.02 / 0.13 3.0 2.5 6 185 ** 5 / 0.9
Summary Of Key Dielectric Characteristics
U.L. RTI - ELECTRO / MECHANICALMATERIAL
Operating Temperatures
Choose the dielectric that best suits your operating temperature
environment. For high temperature applications, such as automotive,
HT offers the right solution. All of our dielectrics are U.L. recognized
(HPLpending).
HT 140°C / 140°C
MP 130°C / 140°C
CML 130°C / 130°C
Applications
Method
Description
1 - Optical
2- Internal TO-220 test
RD2018
3 - Calculation from ASTM 5470
4 - Extended ASTM 5470
5 - ASTM D149
6 - ASTM D150
7 - Internal MDSC test RD2014
8 - U.L.746 E
9 - ASTM D2861
*
CMLis available in prepreg form
*
*Pending
Note: For applications with an expected voltage over 480 Volts AC, Bergquist recommends a dielectric thickness greater than 0.003" (76µm).
Note: Maximum test voltage is a function of material and circuit design.Typical proof test does not represent the maximum.
Note: Circuit design is the most important consideration for determining safety agency compliance.
Water-cooled Heatsink
TO-220 Greased Interface
Circuit Layer (IMS)
Dielectric (IMS)
Metal Base Plate (IMS)
Greased Interface
25°C Water In Water Out
60 lb Force
Temperature of
Transistor Base
(TT ºC)
Temperature of
IMS Base
(TB ºC)
θ(TT - TB)
40W
ºC
W
( )
=
Thermal Impedance
This drawing represents RD 2018 (at 40W) TO-220 thermal
performance (25°C Cold Plate Testing).
U.L. SOLDER LIMIT RATINGMATERIAL
HT* 325°C / 60 seconds
MP 300°C / 60 seconds
CML 260°C / 60 seconds
*Covers all soldering options including Eutectic Gold / Tin.
Thermal Clad has replaced ceramics and DBC in applications due to mechanical robust-
ness and its ability to be fabricated in a wide variety of form-factors.
10
Using Thermal Clad Dielectric Material...
Two-Layer Systems Using FR-4 Circuits
Or Thermal Clad Circuits
Bergquist dielectrics are ideal for applications requiring a two-layer
solution.Two-layer constructions can provide shielding protection and
additional electrical interconnects for higher component density.
Bergquist dielectrics will provide superior thermal performance over
traditional FR-4 constructions. In addition, thermal vias can maximize
thermal capabilities for applications utilizing power components.
When vias can not be used, selecting higher performance dielectrics
can solve thermal issues independently (see graph, below).
DBC Replacement
Replace Ceramic Substrates
Thermal Clad can replace large-area ceramic substrates. It can also be
used as a mechanically durable support for ceramic circuits or direct-
bond copper subassemblies.The copper circuit layer of Thermal Clad
has more current carrying capability than thick-film ceramic technology.
FR-4
FR-4
HT
HT
HT
Direct Die Application
Direct die attach and wirebond are increasingly popular methods of
component mounting to Thermal Clad substrates.A key benefit to this
structure is lower thermal resistance as compared to conventional sur-
face mount component packages soldered to an IMSsubstrate.
When designing circuits using Chip-On-Board (COB) technology it is
important to use the appropriate surface finish to achieve excellent
die mounting and wire bond connections. The die attachment is
accomplished using SnPb, Pb-free solders, eutectic gold/in solder or an
electrical/thermal conductive adhesive, depending on the application
requirements to adhere the die to the substrate.The wirebonding per-
formed to make circuit connections is usually either gold or aluminum.
ENEPIG (Electroless Nickel/Electroless Palladium/Immersion Gold) is
recommended for gold wire and ENIG (Electroless Nickel/ Immersion
Gold) for aluminum wire applications. HT dielectrics are U.L. solder
rated at 325°C/60 seconds, enabling Eutectic Gold/Tin solders.
Heavy Copper
Applications requiring heavy copper for high current or heat
spreading are not limited to single-layer needs. The ability to have
internal layers of heavy copper can provide greater application
flexibility. Direct access to the internal copper layer to directly attach
or mount components provides unique applications capability.
Look for opportunities to reduce the copper thickness. In many appli-
cations, Bergquist T-Clad thermal performance reduces the need for
heavy copper.
Bergquist has the ability to
laminate heavy copper up to
5 oz. (175µm) on the internal
layer utilizing a thicker deposit
of HT dielectric.
The graph depicts the modeled thermal result of various two-layer constructions as a func-
tion of device case temperature. The emphasis is the thermal effect of proper vias utilization.
Close-up view of direct die
attachment in an LED
application. The Thermal
Clad substrate is used to
mount the die or module.
11
Ultra Thin Circuits
Ultra Thin Circuits (UTC) utilize T-Clad
®
dielectrics without the typical
thick base layer. These circuits are often used for component level
packaging where the thick aluminum or copper base is not required
for mechanical or thermal mass. The circuit layer is a “stand-alone”
ceramic submount replacement where the heat spreading and heat
sinking is done in a different location. In addition, UTC can often be
used for standard component package mounting. In some cases, the
thermal performance and heat dissipation of the UTC is adequate to
eliminate the need for heat sinking altogether. The total profile of a
UTC can be as thin as 0.009" (0.23mm) and can be built up into mul-
tilayer structures.This type of structure is also available with Bond-Ply
450 thermally conductive PSA tape pre-applied to the back. See page
15 for examples of this format.
...In Specialty Applications
Pedestal formation through selective dielectric removal.
Dielectric Removal Area
Dielectric Edge Baseplate
Bergquist Dielectric Copper Foil
(Circuit)
Electrical vias to baseplate.
Active Baseplates
Electrical Vias To Baseplate
A copper IMS baseplate can be used as an active circuit with the
use of blind plated electrical via’s that connects the top circuit
layer to the base metal.
Selective Dielectric Removal
Bergquist has developed a process for selectively removing dielec-
tric to expose the baseplate.This surface can be surface finished
like the other circuit pads.We are not limited to geometry or size
of the dielectric removal area. Selective removal features can be
placed very accurately with respect to the circuits.
Pedestal
Using a copper base and by selectively removing the dielectric
a pedestal can be formed moving the base metal up to be
co-planar with adjacent circuits.
Selective dielectric removal.
Copper Foil
(Circuit)
Pedestal
Bergquist Dielectric
Baseplate
Baseplate
Bergquist Dielectric
Photographic example of UTCversus a standard 0.062" (1.57mm) aluminum substrate.
Copper Foil
(Circuit)
Copper-Plated
Blind Via
For more detail regarding design and tolerance recommendations
for active baseplates, please contact your Bergquist representative
for a White Paper.
12
t
Coefficient Of Thermal Expansion
And Heat Spreading
t
Coefficient Of Thermal Expansion
And Solder Joints
METAL / ALLOY
THERMAL
CONDUCTIVITY
[W/mK]
COEFFICIENT OF
THERMAL EXPANSION
[ppm/K] DENSITY
[g/cc]
MODULUS OF
RIGIDITY
[GPa] YIELD STRENGTH
[MPa]
Copper 400 17 8.9 44.1 310
Aluminum 5052 150 25 2.7 25.9 215
Aluminum 6061 150 25 2.7 26 230
t
Strength, Rigidity And Weight
t
Electrical Connections To Base Plate
t
Surface Finish
t
Costs
Coefficient Of Thermal Expansion
And Heat Spreading
The adjacent graph depicts the CTE of the base material in relationship
to the heat spreading capability of the metal. Although Aluminum and
Copper are the most popular base layers used in Thermal Clad, other
metals and composites have been used in applications where CTE mis-
match is a factor.The adjacent table represents standard and non-stan-
dard base layers.
Base Metal Layer Design Considerations
Coefficient Of Thermal Expansion
And Solder Joints
Solder joint fatigue can be minimized by selecting the correct base
layer to match component expansion.The major concern with ther-
mal expansion is the stress the solder joint experiences in power (or
thermal) cycling. Solder joints are not mechanically rigid. Stress
induced by heating and cooling may cause the joint to fatigue as it
relieves stress. Large devices, extreme temperature differential, badly
mismatched materials, or lead-free minimum solder thickness may all
place increased cyclic strain on solder joints.
Solder joint fatigue is typically first associated with ceramic based
components and with device termination. The section on “Assembly
Recommendations” (page 18-19) covers these issues in more detail.
Extra-Long Circuits
Finished circuits up to 25" (635mm) long
13
Base Thickness
Copper and aluminum Thermal Clad is normally purchased in one of
the standard-gauge thicknesses shown in the table below. Non-stan-
dard thicknesses are also available.
Electrical Connections To Base Plate
If a connection to the base plate is desired, copper is the most com-
patible base layer to use. When using electrical or thermal vias, it is
important to match the circuit and base coefficients of thermal TCE
expansion as closely as possible. Otherwise, excess plated-hole stress
will occur during thermal cycles. Other base layer materials can be
used for connection, but will require different connection schemes.
Costs
The most cost effective base layers are aluminum and copper
because they represent industry standards. Copper is more expensive
than aluminum when comparing the like thicknesses, but can be the
less expensive option if design considerations allow for a thinner layer.
As an example, typically the cost of 0.040" (1.0mm) copper is equal
to the cost of 0.125" (3.2mm) aluminum.
Surface Finish
Aluminum and copper base layers come with a uniform commercial
quality brushed surface. Aluminum is also available anodized with
choices of clear, black,blue and red colors.
Standard Thermal Clad Panels
Available in:
18" (457mm) x 24" (610mm)
Usable area: 17" (432mm) x 23" (584mm)
18" (457mm) x 25" (635mm)
Usable area: 17" (432mm) x 24" (610mm)
20" (508mm) x 24" (610mm)
Usable area: 19" (483mm) x 23" (584mm)
Inches Millimeters
0.020 0.50
0.032 0.81
0.040 1.02
0.060 1.52
0.080 2.03
0.125 3.18
Inches Millimeters
0.020 0.51
0.032 0.81
0.040 1.02
0.062 1.57
0.080 2.03
0.125 3.18
0.160 4.06
0.190 4.83
Aluminum - Thicknesses
Copper - Thicknesses
*Standard thicknesses highlighted
1" by 0.125" (25mm by 3.2mm) trace
on 0.003" (76µm) HT dielectric
or 0.006" (152µm) FR-4 dielectric
10
9
8
7
6
5
4
3
2
1
5 10 15 20 25
HT
1 oz (35µm)
2 oz (70µm)
1 oz (35µm)
2 oz (70µm)
Temperature rise comparison graph depicts the significant difference between Bergquist
Dielectric HT and FR-4. Additional comparison charts regarding all Bergquist Dielectrics are
available. Note: No base metal used in calculation.
14
t
Current Carrying Capabilities
t
Heat Spreading Capabilities
t
Flatness In Relationship To Thickness
Current Carrying Capabilities
The circuit layer is the component-mounting layer in Thermal Clad.
Current carrying capability is a key consideration because this layer
typically serves as a printed circuit, interconnecting the components of
the assembly.The advantage of Thermal Clad is that the circuit trace
interconnecting components can carry higher currents because of its
ability to dissipate heat due to I2R loss in the copper circuitry.
Selecting A Circuit Layer
50
40
30
20
10
0050 100
200 250
150
1" by 0.125" (25mm by 3.2mm) trace
on 0.003" (76µm) HT dielectric
or 0.006" (152µm) FR-4 dielectric HT
1 oz (35µm)
3 oz (105µm)
6 oz (210µm)
10 oz (350µm)
1 oz (35µm)
3 oz (105µm)
6 oz (210µm)
10 oz (350µm)
Temperature rise comparison graph depicts the significant difference between Bergquist
Dielectric HT and FR-4. Additional comparison charts regarding all Bergquist Dielectrics are
available. Note: No base metal used in calculation.
Want a cost effective,
optimized circuit design?
This Thermal Clad White Paper addresses specific design
recommendations including mechanical, circuit, soldermask,
fabrication and test options to help optimize your design.
15
Standard Circuit Layer Thickness
Heat Spreading Capability
Dielectric thickness and foil thickness both influence heat spreading
capability in Thermal Clad. Heat spreading is one of the most powerful
advantages derived from IMS. By increasing copper conductor thick-
ness, heat spreading increases and brings junction temperature down.
In some cases very heavy copper can be utilized along with bare die
to eliminate the need for a standard packaged component.
The following graphs depict both the thermal impedance value and
case temperature when relating dielectric and foil thickness.
40 Watt TO-220 soldered to 1" by 1" (25mm x 25mm)
Thermal Clad MP
Bergquist RD2018 Test Method
Dielectric Thickness Inches (µm )
.002"
(51)
1 oz (35µm) circuit foil
3 oz (105µm) circuit foil
6 oz (210µm) circuit foil
10 oz (350µm) circuit foil
.003"
(76) .004"
(102) .005"
(127) .006"
(152) .007"
(178)
40 Watt TO-220 soldered to 1" by 1" (25mm x 25mm)
Thermal Clad MP
Bergquist RD2018 Test Method
Dielectric Thickness Inches (µm)
.002"
(51) .003"
(76) .004"
(102) .005"
(127) .006"
(152) .007"
(178)
1 oz (35µm) circuit foil
3 oz (105µm) circuit foil
6 oz (210µm) circuit foil
10 oz (350µm) circuit foil
Thermal Impedance[°C/W]
MATERIAL WEIGHT REFERENCE THICKNESS
(oz/ft2) inches µm
Copper
(Zinc Treatment)
1 0.0014 35
2 0.0028 70
3 0.0042 105
4 0.0056 140
5 0.0070 175
6 0.0084 210
8 0.0112 280
10 0.0140 350
NOTE: Copper foil is NOT measured for thickness as a control method. Instead,
it is certified to an area weight requirement per IPC-4562. The nominal
thickness given on 1 oz. copper is 0.0014"/35 µm.
CAUTION! Values in IPC-4562 (Table 1.1) are not representative
of mechanical thickness.
Ultra Thin Circuits utilizing Bond-Ply
®
450 PA. See pages 11 and 18 for additional information.
16
“Proof Test” fixture to test multiple number of finished circuit boards at one time.
t
Proof Testing
t
Breakdown Voltage
t
Creepage Distance And Discharge
Proof Test
The purpose of "Proof Testing" Thermal Clad substrates is to verify
that no defects reside in the dielectric material. Because testing
requires that voltages be above the onset of partial discharge, we rec-
ommend the number of “Proof Tests” be kept at a minimum.
The term "Partial Discharge" includes a broad spectrum of life
reducing (i.e. material damaging) phenomena such as:
1. Corona discharge
2. Treeing and surface contamination
3. Surface discharges at interfaces, particularly during fault
induced voltage reversal
4. Internal discharges in voids or cavities within the dielectric
Electrical Design Considerations
The purpose of the “Proof Test” is to verify that there has been no
degradation of the dielectric insulation due to the fabrication process
or any material defects. Continued testing at these voltage levels will
only take away from the life of the dielectric on the circuit board. It
has been repeatedly verified that “Proof Testing” above the inception
of partial discharge (700 Vac or 1200 Vac with proper use of solder-
mask) will detect any and all defects in the dielectric isolation in the
Thermal Clad circuit board. Any micro-fractures, delaminations or
micro-voids in the dielectric will breakdown or respond as a short
during the test.
The use of a DC “Proof Test” is recommended, from an operator
safety standpoint.The voltage levels typically used are 1500 to 2250
VDC. Due to the capacitive nature of the circuit board construction,
it is necessary to control the ramp up of the voltage to avoid nui-
sance tripping of the failure detect circuits in the tester and to main-
tain effective control of the test. This is to avoid premature surface
arcing or voltage overshoot. There is safety consideration when DC
testing, in that the operator must verify the board tested is fully dis-
charged, prior to removing from the test fixture. A more detailed dis-
cussion of “Proof Test” is available upon request.
Breakdown Voltage
The ASTM definition of dielectric breakdown voltage is: the potential
difference at which dielectric failure occurs under prescribed condi-
tions in an electrical insulating material located between two elec-
trodes. This is permanent breakdown and is not recoverable. ASTM
goes on to state that the results obtained by this test can seldom be
used directly to determine the dielectric behavior of a material in an
actual application.This is not a test for “fit for use” in the application,
as is the “Proof Test”, which is used for detection of fabrication and
material defects to the dielectric insulation.
17
FOR POSITION ONLY
Typical Flashover Voltage in Various Media
0.003" (76µm) Dielectric, 25mm circular electrodes
Typical Flashover Voltage in Various Media
0.006" (152µm) Dielectric, 25mm circular electrodes
Creepage Distance And Discharge
Creepage distance and discharge has to be taken into account
because Thermal Clad dielectrics often incorporate a metal base layer.
Circuit board designers should consider “Proof Testing” requirements
for: conductor-to-conductor and conductor-to-circuit board edge or
through holes. The graphs below depict flashover: without solder-
mask, with soldermask and under oil.
Leakage Current HiPot Testing
Due to the variety of dielectric types, thicknesses and board layouts,
not all boards test alike.All insulated metal substrates closely resemble
a parallel plate capacitor during HiPot testing. Capacitance is equal to:
C = A/d
where:
= Permittivity (Dielectric Constant)
A = Surface Area
d = Distance (Dielectric Thickness)
The capacitance value changes with different configurations of materi-
als and board layouts. This can be demonstrated where one board
fails the test and another passes, but when both are actually tested for
dielectric strength and leakage current in a controlled environment,
both pass.Therefore, it is very important to properly design the test-
ing and test parameters with the material characteristics in mind.Test
set-up and parameters that over-stress or do not consider reactance
of the material and its capacitive and resistive components, can lead
to false failures and/or test damage of the board.
Another test characteristic that is generally misunderstood with
insulated metal substrates is the leakage and charge current that take
place during the test. In most cases, the leakage current value on
insulated metal substrates is much smaller than the measurement
capability of a typical HiPot tester. What is most misunderstood is the
charge current that takes place during the test. Leakage current
measurements can only be realized once the board has been brought
to the full test voltage (DC voltage) and is held at that voltage during
the test. This current value and rate dI/dT is directly related to the
capacitance of the board. Therefore, a board that has an effective
capacitance higher than another board will have a higher charge
current rate than the one with a lower effective capacitance. This
does not reflect the leakage current or the voltage withstand of the
dielectric insulation instead, it represents the characteristic transient
response of the dielectric. Therefore, one is not able to determine
comparable leakage current based on the instantaneous charge
current. For accurate leakage test data, bring the board up to full DC
test voltage and hold.
MEASURED CURRENT - CHARGE CURRENT = LEAKAGE CURRENT
18
Solder Assembly
Solder joints deserve additional consideration in the design of Thermal
Clad assemblies.This section covers solder surface finishes, application
and thickness, alloy and flux.
Surface Finishes
Standard circuit board finishes are available for Thermal Clad
circuit boards.
• ENIG (Electroless Nickel/Immersion Gold)
• OSP (Organic Solderability Protectant)
• Immersion silver or tin and lead-free HASL
• Standard tin/lead HASL
• ENEPIG(Electroless Nickel/Electroless Palladium/Immersion Gold)
• Electroless gold
Application and Thickness - Solder Paste
The typical application technique is metal stencil. Dispensing of solder to
specific locations is used for secondary operations or special attachment
requirements. No other decision will effect the reliability of the solder
joint as much as the thickness of the solder to be used.A minimum of
0.004" (102µm) is recommended (after reflow).This thickness dissipates
stress buildup in the joint. Additional information regarding solder joint
reliability is offered in the appendix.
Note:Additional thickness and/or larger stencil opening may need to be
utilized for RoHS compliance applications.Use profile recommended by the
component manufacturer.
5
3
Ramp-down
Ramp-up Stabilization/soak
(90-120 s)
3°C/s
max
6°C/s
max
Assembly Recommendations
Now Available
T-Clad Bond-Ply 450 PA
Thermal Clad with Bond-Ply 450 PA is a
thermally conductive adhesive tape that is the
first of many pre-applied offerings to come.
This material features a release liner on the
back side for easy removal and application
to a heat sink. T-Clad PA substrate release liners
can withstand high temperatures and will maintain
adhesion and release characteristics even after exposure to the
extreme heat of solder reflow. For a complete data sheet, contact
Bergquist Sales.
Wire soldering on Thermal Clad.
Standard stars and squares in the most popular LEDfootprints
available through distribution. Contact Bergquist Sales for more
information.
19
Connection Techniques
Connection techniques common throughout the industry are being
used successfully on Thermal Clad IMS substrates. Surface mount
connectors are manufactured using plastic molding materials with
thermal coefficients of expansion that roughly match the characteris-
tics of the baseplate metal. However, the plastic molding compounds
do have a different thermal capacity and thermal conductivity that
can cause stress in the assembly as it cools after soldering and during
any significant temperature excursion. Process-caused thermal mechani-
cal stress is specific to the solder reflow process used. For this reason,
designs that capture the metal pin without rigidity are preferred, partic-
ularly if the major dimension of the connector is large.
Pin Connectors
Pin connectors and pin headers are often used in Thermal Clad
assembly when an FR-4 panel is attached to a Thermal Clad assembly.
The differential coefficient of expansion between the control panel and
the base metal will cause stress in the solder joint and dielectric.The
most advanced designs incorporate stress relief in the fabrication of
the pin. Redundant header pins are often used to achieve high current
carrying capacity.
Manufacturers such as AutoSplice and
Zierick have off the shelf pins ideal for IMS
applications. Custom pins and connectors are
also available.
Custom Connectors
In the example above, the application required a large cable connec-
tion to the T-Clad IMSboard. Precautions were taken for the best
electrical connection with minimized mechanical strain on the etched
circuit.This solution addresses both electrical and mechanical fasten-
ing.The small holes allow for complete void-free soldering. Also, the
insulated shoulder washer prevents shorting to the base plate.These
types of connectors are usually custom made and are not commer-
cially available.
Wire Bonding – Direct Die
Wire bonding is particularly
useful in the design of packages
with Chip-On-Board (COB)
architecture. This technique
uses the surface mount and
interconnect capability of
Thermal Clad in a highly effi-
cient thermal design. See
page 10 for additional infor-
mation.
Power Connections
Only a few companies supply spade or threaded fastener con-
nectors for surface mount power connections. In many cases these
are lead frame assemblies soldered to the printed circuit pads and
bent to accommodate the shell used for encapsulation. Designs incor-
porating stress relief and a plastic retainer suitable for high amperage
are also available. Thru-board connectors will require adherance to
fabrication design rules for IMS PWB’s.
Edge Connectors
When using edge connectors as part of the Thermal Clad printed
wiring pattern, it is suggested that interfacing conductors be finished
with a hard gold plating over sulfamate nickel plating. A 45° chamfer
is recommended when using an edge connector. Remember to main-
tain the minimum edge to conductor distance to prevent shorting. Flex attachment on Thermal Clad.
This Tyco Electronics
TM
SMT thru-board
connector provides a way to bring power
from the underside of a Thermal Clad IMS
board, eliminating issues of dressing wires on
the top side of LED boards. Close up view of a direct die attachment
in a power application.
20
Sil-Pad
®
Sil-Pad is the benchmark in thermal interface materials.The Sil-Pad family of materials
are thermally conductive and electrically insulating. Available in custom shapes, sheets,
and rolls, Sil-Pad materials come in a variety of thicknesses and are frequently used in
SMT applications such as:
• Interface between thermal vias in a PCB, and a heat sink or casting
• Heat sink interface to many surface mount packages
Hi-Flow
®
The Hi-Flow family of phase change materials offers an easy-to-apply thermal interface
for many surface mount packages.At the phase change temperature, Hi-Flow materials
change from a solid and flow with minimal applied pressure.This characteristic optimizes
heat transfer by maximizing wet-out of the interface. Hi-Flow is commonly used to
replace messy thermal grease.
Bergquist phase change materials are specially compounded to prevent pump-out of
the interface area, which is often associated with thermal grease.Typical applications for
Hi-Flow materials include:
• Intel CoreTM Series, Pentium®, PhenomTM,Athlon®, and other high performance CPUs
• DC/DC converters
• Power modules
Hi-Flow materials are manufactured with or without film or foil carriers.
Custom shapes and sizes for non-standard applications are also available.
Mid Power Application with Bond-Ply or Sil-Pad
Power Device
Sil-Pad or
Bond-Ply FR-4
High Power Application
Hi-Flow without Thermal Clad
High Power Application
Hi-Flow with Thermal Clad
Power Device
Processor
Thermal Clad
Hi-Flow
Hi-Flow Heat
Spreader
Heat
Spreader
FR-4 Board
Heat
Spreader
Intel CoreTM and
Pentium®are registered trademarks of Intel Corporation.
PhenomTM and
Athlon®are registered trademarks of Advanced Micro Devices, Inc.
Solutions For Surface-Mount Applications
21
Bond-Ply
®
and Liqui-Bond
®
The Bond-Ply family of materials are thermally conductive and electrically isolating.
Bond-Ply is available in a pressure sensitive adhesive or laminating format. Liqui-Bond is a
high thermal performance liquid silicone adhesive that cures to a solid bonding
elastomer. Bond-Ply provides for the mechanical decoupling of bonded materials with
mismatched thermal coefficients of expansion.Typical applications include:
• Bonding bus bars in a variety of electronic modules and sub assemblies
Attaching a metal-based component to a heat sink
• Bonding a heat sink to a variety of ASIC, graphic chip,and CPU packages
• Bonding flexible circuits to a rigid heat spreader or thermal plane
Assembly tapes for BGA heat spreader
Attaching PCB assemblies to housings
Gap Pad
®
and Gap Filler
The Gap Pad product family offers a line of thermally conductive materials which are
highly conformable.Varying degrees of thermal conductivity and compression deflection
characteristics are available.Typical applications include:
• On top of a semiconductor package such as a QFP or BGA. Often times, several
packages with varying heights can use a common heat sink when utilizing Gap Pad.
• Between a PCB or substrate and a chassis, frame, or other heat spreader
Areas where heat needs to be transferred to any type of heat spreader
• For interfacing pressure sensitive devices
• Filling various gaps between heat-generating devices and heat sinks or housings
Gap Pads are available in thickness of 0.010" (0.254mm) to 0.250" (6.35mm), and in cus-
tom shapes, with or without adhesive. Gap Fillers are available in cartridge or kit form.
Top Efficiency In
Thermal Materials For
Today’s Changing Technology.
Contact Bergquist for additional information regarding
our Thermal Solutions.We are constantly innovating
to offer you the greatest selection of options and
flexibility to meet today’s changing technology.
Lower Power Application
with Gap Pad
Gap Pad or Gap Filler
Power
Device
Heat
Spreader
FR-4 Board
Where Thermal Solutions Come Together
22
D 149 Test Methods for Dielectric Breakdown Voltage and Dielectric Strength
of Solid Electrical Insulating Materials at Commercial Power Frequencies
D 150 Test Methods for AC Loss Characteristics and Permitivity (Dielectric Constant)
of Solid Electrical Insulating Materials
D 257 Test Methods for DC Conductance or Impedance of Insulating Materials
D 374 Test Methods for Thickness of Solid Electrical Insulation
D 3165 Test Method for Strength Properties of Adhesives in Shear by Tension
Loading of Single-Lap-Joint Laminated Assemblies
D 5470 Test Methods for Thermal Transmission Properties of Thin Thermally
Conductive Solid Electrical Insulating Materials
60093 Methods of test for volume resistivity and surface resistivity of
solid electrical insulating materials
60243-1 Methods of test for electric strength of solid insulating materials -
Part 1:Tests at power frequencies
60250 Recommended methods for the determination of the permitivity and
dielectric dissipation factor of electrical insulating materials at power,
audio,and radio frequencies including metre wavelengths
60626-2 Combined flexible materials for electrical insulation-
Part 2: Methods of test
2221 Generic Standard on Printed Board Design
6012 Qualifications and Performance Specification of Rigid Printed Boards
600 Acceptance of Printed Boards
TM-650 Cleanliness (2.3.35 & 2.3.26)
TM-650-2.4.22 Bow and Twist
TM-650-2.4.8 Peel
SM-840C Soldermask
ANSI/IPC-SM-782 Surface Mount Land Patterns (configurations and design rules)
Adhesives Determination of tensile lap-shear strength of rigid-to-rigid
bonded assemblies
ASTM
IPC
IEC
ISO 4587
Surface
Mount
Appendix
23
Thermal Clad Configurations
Custom Circuit
Bergquist Thermal Clad substrates are custom configured to your
design parameters at our Prescott,Wisconsin facility. Our field applica-
tion support personnel in conjunction with our mechanical and
process engineers are available to assist you in taking your design from
paper to finished product. Engineering is available for the following
construction parameters and options.
• Artwork layout recommendations
• Base metal requirements and mechanical configuration
• Dielectric thickness
• Copper weights (35-350µm / 1-10 oz)
• Solder mask layouts
All common circuit finishes
• Tooling/singulation options
Panel Form
Dimensions:
• 18" x 24" (457mm x 610mm)
18" x 25" (457mm x 635mm)
20" x 24" (508mm x 610mm)
• Foil Thickness: 35-350µm (1-10 oz)
Base Plate Metals:
• Aluminum 6061-T6, 5052-H34, standards
from 0.020" to 0.190" (0.5mm to 4.83mm)
• Copper 110 Full-Hard, standard from
0.020" to 0.125" (0.5mm to 3.2mm)
Sheet And Roll Format
CML (Circuit Material Laminate) is a ceramic filled polymer that forms
a strong, thermally conductive bond to metal heat spreaders and is an
excellent alternative to pre-preg.
• 24" (610mm) Roll Standard (custom sizes are available)
• Maximum roll length of 2000' (610m)
• Sheets 18"x 24" (457mm x 610mm)
and 20" x 24" (508mm x 610mm)
U.L.Certifications Directory
For information regarding the U.L. recognition status of Bergquist
Thermal Clad materials and “Prescott Operations” circuit fabrication,
the U.L. website provides the latest information.
Using the address: http//www.ul.com select; Online Certifications
Directory. Enter one of the following file numbers: U.L.File Number, to
the applicable Bergquist file.
In each group there is guide information which will give a
further description of the categories listed.
In each group the recognized materials or fabricated circuit
board types will be listed.
QMTS2.E121882
Polymeric Materials - Filament-wound tubing, Industrial
Laminates, Vulcanized Fiber, and Materials for Use in
Fabricating Recognized Printed Wiring Boards - Components.
ZPMV2.E122713
Wiring, Printed - Component
Notes
TCDG_0909
Corporate Headquarters and Sales Office:
18930 West 78th Street
Chanhassen, MN 55317
Circuits Manufacturing Facility:
1600 Orrin Road
Prescott, WI 54021
Toll Free: (800) 347-4572 • Main: (952) 835-2322 • Fax: (952) 835-0430 • www.bergquistcompany.com
Thermal Products • Membrane Switches • Touch Screens
DOMESTIC AGENTS
For a complete list of Bergquist sales representatives in the U.S. contact
The Bergquist Company: 1-800-347-4572.
INTERNATIONAL SALES OFFICES
CHINA
Tel: 86-21-6464-2206
Fax: 86-21-6464-2209
GERMANY
Tel: 49-4101-803-230
Fax: 49-4101-803-100
HONG KONG
Asian Headquarters
Tel: 852-2690-9296
Fax: 852-2690-2344
THE NETHERLANDS
European Headquarters
Tel: 31-35-5380684
Fax: 31-35-5380295
SOUTH KOREA
Tel: 82-31-448-0382
Fax: 82-31-448-0383
AUSTRALIA
AUSTRIA
BELGIUM
BRAZIL
CANADA
CHINA
DENMARK
FINLAND
FRANCE
HOLLAND
HONG KONG
ISRAEL
ITALY
JAPAN
MALAYSIA
MEXICO
NEW ZEALAND
NORWAY
PORTUGAL
RUSSIA
SINGAPORE
SPAIN
SWEDEN
SWITZERLAND
TAIWAN
THAILAND
TURKEY
INTERNATIONAL AGENTS
TCDG_Cover_09.09.qxp 9/8/2009 1:42 PM Page 2

Products

THERM PAD 17.45MMX14.27MM GRAY
Available Quantity12670
Unit Price0.2
THERM PAD 21.84MMX18.8MM GRAY
Available Quantity7216
Unit Price0.24
THERM PAD 21.84MMX18.8MM GRAY
Available Quantity1103
Unit Price0.24
THERM PAD 39.7MMX26.67MM GRAY
Available Quantity7062
Unit Price0.39
THERM PAD 41.91MMX28.96MM GRAY
Available Quantity5831
Unit Price0.41
THERM PAD 19.05MMX12.7MM PINK
Available Quantity5914
Unit Price0.44
THERM PAD 21.84MMX18.8MM GREEN
Available Quantity3270
Unit Price0.44
THERM PAD 24MMX21.01MM GREEN
Available Quantity3853
Unit Price0.5
THERM PAD 21.84MMX18.8MM PINK
Available Quantity1907
Unit Price0.5
THERM PAD 19.05MMX12.7MM BEIGE
Available Quantity1229
Unit Price0.68
THERM PAD 24MMX21.01MM PINK
Available Quantity1436
Unit Price0.69
STAR THERMAL CLAD BOARD CREE XRE
Available Quantity4342
Unit Price1.67
STAR THERM CLAD BD GOLDEN DRAGON
Available Quantity2791
Unit Price1.67
STAR THERM CLAD BOARD NICHIA PWR
Available Quantity1274
Unit Price1.67
STAR THERM CLAD BRD OSRAM OSTAR
Available Quantity1160
Unit Price1.67
THERM PAD 19.05MMX12.7MM GREEN
Available Quantity4100
Unit Price0.3
STAR THERM CLAD BD GOLDEN DRAGON
Available Quantity989
Unit Price34.26
STAR THERM CLAD BRD LUMEX SML-LX
Available Quantity9708
Unit Price1.52
STAR THERM CLAD BRD LITE-ON LOPL
Available Quantity9694
Unit Price1.52
STAR THERM CLAD BOARD LUXEON K2
Available Quantity8066
Unit Price1.52