SP400-0.007-00-104 Bergquist, SP400-0.007-00-104 Datasheet - Page 21

• Manufacturer Part Number: SP400-0.007-00-104
• Description: THERMAL PAD TO-220 .007" SP400
• Manufacturer: Bergquist
• Series: Sil-Pad® 400r

Specifications of SP400-0.007-00-104

• Usage: TO-218, TO-220, TO-247
• Shape: Rectangular
• Outline: 25.40mm x 19.05mm
• Thickness: 0.007" (0.178mm)
• Backing, Carrier: Fiberglass
• Color: Gray
• Thermal Resistivity: 1.13°C/W
• Thermal Conductivity: 0.9 W/m-K
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Adhesive: -
• Other names: 3223-07FR-104; BER204; BG426704

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.
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.
This Tyco Electronics
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.
TM
SMT thru-board
Custom Connectors
In the example above, the application required a large cable connec-
tion to the T-Clad IMS board. 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 par ticularly
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.
Flex attachment on Thermal Clad.
Close up view of a direct die attachment
in a power application.
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