Screws for Mounting LPA Packages

American National Standard HEXAGONAL CAP SCREWS

Screw Number T/ inch Factor Torque,
(in-lbs)

Screw Dia.
(in)

Clear Size
(in)
Torque
(N-m)
0-80 80 0.50 1.79 0.060 0.063 0.22
2-56 56 0.71 3.57 0.089 0.089 0.40
4-40 40 1.00 5.00 0.112 0.116 0.56
6-32 32 1.25 6.25 0.138 0.114 0.70

 

Metric Series HEXAGONAL SOCKET cap screws

Screw Number T/ inch Factor Torque
(N-m)

Screw Dia.
(in.)

Clear Size
(mm)
Torque
(in-lbs)
M1.5-.35 72 0.83 0.20 0.059 1.60 1.76
M2.5-.46 55 1.00 0.46 0.098 2.65 4.07
M3-.50 50 1.09 0.77 0.118 3.15 6.81 
M3-.60 42 1.43 0.77 0.118 3.15 6.81 

 

Mounting holes for common StratEdge heat Flanges

Part Number Mounting Hole
(in.)
Mounting Hole
(mm)
English
Screw
Metric
Screw
580286 0.07 1.778 0-80 M1.5-.35
580274 0.09 2.286 2-56 M2.5-.46
LL802302-001 0.13 3.302 4-40 M2.5-.46
LL802302-001 0.13 3.302 6-32 M3-.50
        M3-.60


The use of ground or thermal pads under the package is NOT recommended.

The use of low tack, ductile adhesives to improve grounding and thermal performance has not been investigated by StratEdge. Customers considering this mounting should consider a package design with a thicker, stiffer base.

These are maximum recommended values.  Assembly for all but the most rigorous mechanical environments is recommended at 80% of these maximum values
The recommended procedure to mount a part requiring four screws is as follows:

  1. Place two screws on opposite corners and adjust just finger tight.
  2. Place two screws on the remaining corners and adjust finger tight.
  3. Tighten the first two screws to 40% torque, and then the other two screws to 40% torque.
  4. Repeat this pattern up to the 80% final torque. 

For further assistance, contact Applications Engineering at (858) 569-5000, or by e-mail at info@StratEdge.com.