Differences

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--- electronics:torque_standards_for_power_packages [2024/01/18 02:48] – [onsemi] mithat
+++ electronics:torque_standards_for_power_packages [2024/01/18 02:50] (current) – [onsemi] mithat
@@ Line 58: / Line 58: @@
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-However, the text implies that torque cannot be used to set the device pressure with conical washers because, "The assembler applies torque until the washer depresses to half its original height. (Tests should be run prior to setting up the assembly line to determine the proper torque for the fastener used to achieve 50% deflection." Thus, it appears the washer determines the pressure on the device rather than torque on the screw.
+However, the text implies that torque cannot be used to set the device pressure with conical washers because, "The assembler applies torque until the washer depresses to half its original height. (Tests should be run prior to setting up the assembly line to determine the proper torque for the fastener used to achieve 50% deflection." Thus, it appears the washer determines the pressure on the device rather than torque on the screw, because torque on the screw is determined by the amount needed to compress the washer just right.
 Perhaps not surprisingly then, specific torque ratings are difficult to derive from this note. However, it shows for TO-220 packages remarkable consistent thermal resistances for greased mica mounting with unspecified hardware over 2 to 6 in-lbs (0.23 to 0.68 N*m). One table shows a torque of 8 in-lbs (0.90 N*m) used with a TO−220AB device.