PRELIMINARY PRODUCT
DATA SHEET
LEADER IN THERMAL MANAGEMENT: DESIGN, INNOVATION AND MATERIALS
Seals
THERMAL MANAGEMENT FOR BGAs
A new generation of advanced materials offers performance and
manufacturing advantages for Ball Grid Array assembly.
The explosive growth of
array packaging presents
new challenges to the users
and suppliers of high per-
formance materials for semi-
conductor assembly.
Traditional materials are
no longer capable of han-
dling the requirements of
these high density pack-
ages. Chomerics’ family of
thermal products has been
designed to meet the needs
of this burgeoning market.
Heat Spreader
THERMFLOW
™
Phase-Change
Interface Pad
THERMATTACH
®
Thermally
Conductive T ape
Substrate
SUPERIOR PERFORMANCE
— phase-
change material replaces thermal grease
with a stress-free interface on backside of
flip chip die
• Eliminates thermal cycling “pump-out” concerns
• Absorbs mismatch in CTE between the silicon
die and the lid
LOWER INSTALLED COSTS
— one-step
process for mounting stiffeners or lids to
the substrate
• Eliminate time-consuming, wasteful
dispensing steps and curing cycles
• Reduce concerns of solder ball fatigue
caused by rigid adhesive systems
• Pre-apply THERMFLOW pads and
THERMATTACH tape to heat spreaders,
stiffeners and lids
THERMATTACH
®
Thermally Conductive BGA Assembly Tapes
DESCRIPTION
THERMATTACH tapes have been designed to provide
a high performance bond in the assembly of EBGA
(Enhanced Ball Grid Array) and TBGA (Tape Ball Grid
Array) semiconductor packages. Their thermally conduc-
tive filler ensures superior package performance when
used to bond the flex or laminate substrate to stiffeners
and heat spreaders.
In addition to offering excellent adhesive and thermal
characteristics, these compliant materials absorb mis-
matches in CTE (coefficient of thermal expansion) of
various package materials. They have been formulated
to be ionically clean in order to eliminate concern over
corrosion on the substrate or on plated stiffeners and
heat spreaders.
THERMATTACH BGA assembly tapes are designed
and tested to meet the rigorous performance demands
of the semiconductor packaging industry, including HAST
(Highly Accelerated Stress Test) and PCT (Pressure
Cooker Testing).
Supplied in rolls or on reels, THERMATTACH Tapes can
be die-cut to component dimensions.
THERMA TTACH T421 and
T422 T apes
Ideally suited for roller lamination
techniques, these transfer adhesives
help ensure void-free assemblies
while reducing processing times. The
T421 and T422 materials have no car-
rier, allowing clean cutting and rout-
ing. There is no particle contamination
of the bond pad or lamination area.
THERMA TTACH T424 and
T427 T apes
These configurations offer a choice
of carrier. The T424 tape consists of
a thermally conductive pressure-
sensitive acrylic adhesive coated on
fiberglass. The system is embossed
with a unique pattern to provide
void-free laminations. In the T427
tape, the thermally conductive,
pressure-sensitive acrylic adhesive
is coated on a Kapton
†
MT carrier.
This system provides excellent
electrical isolation properties.
TYPICAL PROPERTIES T421 T422 T424 T427 TEST METHOD
Binder Acrylic Acrylic Acrylic Acrylic —
Filler
Aluminum Aluminum Aluminum Aluminum
—
Oxide Oxide Oxide Oxide
Carrier — — Fiberglass Kapton MT —
Thickness, inch (mm) 0.002 (0.05) 0.003 (0.08) 0.007 (0.18) 0.007 (0.18) ASTM D374
Thermal Impedance,
0.35 (2.26) 0.38 (2.45) 0.65 (4.19) 0.60 (3.87) ASTM D5470
°C-in
2
/W (°C-cm
2
/W)
Thermal Conductivity, W/m-K 0.46 0.43 0.40 0.43 ASTM D5470
Voltage Breakdown, Vac — — 4000 6000 ASTM D149
Volume Resistivity, ohm-cm >1.0 x 10
14
>1.0 x 10
14
>1.0 x 10
15
>1.0 x 10
15
ASTM D257
Specific Gravity 1.5 1.6 1.5 1.75 ASTM D792
Peel Adhesion, lb/in (kN/m) 3.4 (0.6) 3.4 (0.6) 3.4 (0.6) 2.75 (0.5) ASTM D1000
Die Shear Adhesion, psi (MPa) 150 (1.04) 150 (1.04) 180 (1.24) 150 (1.04) CTP No.54**
Tack Adhesion, gm 500 500 700 500 Polyken PSTC*
† Trademark of Du Pont
*Pressure Sensitive Tape Council **Chomerics Test Procedure
CONSTRUCTION
THERMAL
ELEC.MECHANICAL.