Application Note

VISHAY SEMICONDUCTORS
www.vishay.com
Modules
Application Note
Mounting Instructions for INT-A-PAK Modules
by Kevin Liu
This application note introduces Vishay´s INT-A-PAK (IAP)
modules. It covers their key features and gives instructions
for using heatsinks with the modules.
IAP modules are designed to provide reliable performance.
A single housing is used to integrate power components,
providing higher power density. Various die selections are
available in several configurations.
INTRODUCTION
Vishay’s IAP modules are distinguished by these key
features:
• Fully isolated from the metal base, allowing common
heatsink and compact assemblies to be built
• Wire-bonded internal connections
• Screwable electrical terminals secured against axial
pull-out. They are fixed to the module housing via a
click-stop feature
• Low junction-to-case thermal resistance
Important factors in the assembly process are:
• Heatsink design
• Power leads size/area
• Distance from adjacent heating parts
Fig. 1 - Examples of IAP Modules
• Protection against electrostatic discharge (ESD)
Recommendations for each of these items and requirements for mounting IAP modules to the heatsink are discussed in the
following sections.
IGBT, MOSFET, and Ultrafast diode modules are sensitive to ESD. All IAP modules built with such configurations are protected
against ESD during shipment; they are separated in a carton box and protected by an antistatic sponge. Anyone handling or
working with the modules during the assembly process must wear a conductive grounded wristband.
HEATSINK SPECIFICATION
The contact surface of the heatsink must be flat, with a recommended tolerance of < 0.03 mm (< 1.18 mils) and a levelling depth
(surface roughness) of < 0.02 mm (< 0.79 mils), according to DIN/ISO 1302. In general, a milled or machined surface is
satisfactory if prepared with tools in good working condition. The heat sink mounting surface must be clean, with no dirt,
corrosion, or surface oxides. It is very important to keep the mounting surface free from particles exceeding 0.05 mm (2 mils) in
thickness.
Revision: 21-Jan-14
Document Number: 95382
1
For technical questions within your region: [email protected], [email protected], [email protected]
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
APPLICATION NOTE
ESD PROTECTION
Application Note
www.vishay.com
Vishay Semiconductors
Mounting Instructions for INT-A-PAK Modules
THERMAL COMPOUND
Coat the heatsink surface and the power module base plate uniformly with a good quality thermal compound. Apply uniform
pressure on the package to force the compound to spread over the entire contact area. The purpose of thermal grease is to fill
gaps at the base plate/heatsink interface, and its use is recommended to ensure low case-to-sink thermal resistance. The
thermal conductivity of the compound should be not less than 1.5 W/mK. The suggested thermal grease is DC340
(Dow Corning), silicone-free HTCP (Electrolube), or an equivalent. Screen printing and rubber rolling are the preferred methods
for applying the grease. A final grease layer thickness in the range of 80 μm to 100 μm is considered suitable for most
applications.
MOUNTING TO HEATSINK
The module baseplate is typically slightly bended with convexity not exceeding 0.19 mm (7.8 mils) when measured between the
two fixing holes. This provides an optimal contact area with the heatsink.
Confirm that there are not any foreign particles on the surface of the screen tooling and plate. Place a suitable amount of thermal
compound on the plate and spread it equably by using a roller or spatula. Thermal grease contact and distribution will be
improved during the first hours and after heating up the system for the first time.
Bolt the module to the heat sink using the fixing holes. An even amount of torque should be applied for each individual mounting
screw. For proper mounting it is recommended to use M6 screws secured by a lock washer and flat washer. Please refer to
each individual data sheet to find the maximum torque that can be applied. A torque wrench that is accurate in the specified
range must be used in mounting the module to achieve optimum results.
The minimum suggested thread depth is 10 mm to 11 mm (0.40 in to 0.43 in) in heatsinks. All mounting holes should be free of
burrs. The first mounting screw should be tightened to one third of the recommended torque; the second screw should then be
tightened to the same torque.
Over-tightening the mounting screw may lead to deformation of the package, which would hence increase the thermal
resistance and damage the semiconductors. After a period of three hours, check the torque with a final tightening in the opposite
sequence to allow the spread of the compound.
POWER LEADS OR BUS BARS CONNECTION
An even amount of torque should be applied for each individual screw. For proper connection, it is recommended to use fit
screws (refer to the individual datasheet or outline dimensions) secured by a lock washer and flat washer. The maximum thread
depth into the module mounting studs should conform to each individual package outline drawing in the datasheet. Also refer
to each individual datasheet to find the maximum torque that can be applied. A torque wrench that is accurate in the specified
range must be used in fixing screws of the power leads or bus bars to achieve optimum results.
SIGNAL TERMINAL AND HOUSING CONNECTION
APPLICATION NOTE
For IAPs built with black plastic housing, we recommend using receptacle fast-on terminals (with locking lance, for 2.8 x 0.8 tab
(series 110) ref. PN.AMP 150571-2 or equivalent) and tinned copper stranded cable (UL 758, style 1558, AWG 22 (0.32 mm2) laid
19 x 0.16 ETFE insulation, ext. dia. 1.25 mm, temperature rating 125 °C). In addition, a 2-way polarized connector housing can be
used, as shown in the dimensional detail (the represented version refers to left “SX” and right “DX” connector housings) (Fig. 2).
For IAPs built with white plastic housing, we recommend using receptacle fast-on terminal with locking lance, for 2.8 x 0.5 tab
(series 110) ref. PN.AMP 42067-1 or equivalent.
Revision: 21-Jan-14
Document Number: 95382
2
For technical questions within your region: [email protected], [email protected], [email protected]
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
Application Note
www.vishay.com
Vishay Semiconductors
Mounting Instructions for INT-A-PAK Modules
2 ways polarized connector
housing, dimensional detail
590 ± 10
0.9-0.1
0.1
1.0
30° 5.0
1.8
Ref
10.4
20.0
6.8
A - DX
0.1
38
Ref
90°
1.3+0.05
2.8
0.1
+0.05
3.8
Not twisted both ends
0.5 x 30°
A
0.9
Ref
0.7
Ref
2.0
Burrs not allowed
A
2.1+0.1
3.0
9.8+0.05
2.4
Ref
5.8+0.1
R 0.2
Max.
0.3
1.0
590 ± 10
Sec. B - B
6.8
0.5 x 30°
Not twisted both ends
A - SX
Sec. A - A
30°
B
B
38
Ref
10.5
APPLICATION NOTE
Fig. 2
Revision: 21-Jan-14
Document Number: 95382
3
For technical questions within your region: [email protected], [email protected], [email protected]
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
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