electronics:torque_standards_for_power_packages
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electronics:torque_standards_for_power_packages [2022/06/02 22:20] – [Discussion of data from sources] mithat | electronics:torque_standards_for_power_packages [2024/01/18 02:48] – [onsemi] mithat | ||
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====== Torque Standards for Power Packages ====== | ====== Torque Standards for Power Packages ====== | ||
- | ===== Recommendations ===== | ||
<WRAP center round info 60%> | <WRAP center round info 60%> | ||
The recommendations below are based on current data. As more sources are found, these recommendations may change. | The recommendations below are based on current data. As more sources are found, these recommendations may change. | ||
</ | </ | ||
- | The best data appears to be that provided in STMicroelectronics' | + | ===== Recommendations ===== |
+ | |||
+ | ==== STMicroelectionics ==== | ||
+ | |||
+ | Comprehensive | ||
^ Package | ^ Package | ||
|TO-220 | |TO-220 | ||
- | |TO-220SG | ||
- | |Pentawatt | ||
- | |Heptawatt | ||
|TO-220FP | |TO-220FP | ||
- | |ISOWATT220 | ||
|TO-247 | |TO-247 | ||
- | |TO-218 | 0.55 | 1.00 | | + | |TO-247-4 | 0.55 | 1.00 | |
+ | |TO-3P | ||
+ | |TO-3PF | ||
- | Use of M3 screws is assumed | + | The kind of insulator (mica, silicone, etc.) isn't specified. |
+ | {{: | ||
- | ===== Discussion | + | STMicroelectronics' |
- | STMicroelectionics(([[https://www.st.com/resource/en/ | + | However, the maximum torque is slightly contradicted here (emphasis added): |
+ | |||
+ | > Suggested maximum torques for M3 screws are //80Nxcm// for TO220, PENTAWATT, HEPTAWATT, MULTIWATT and CLIPWATT 19 H packages. | ||
+ | |||
+ | This leads to the following | ||
^ Package | ^ Package | ||
- | |TO-220 | ||
|TO-220SG | |TO-220SG | ||
- | |Pentawatt | + | |TO-220 |
- | |Heptawatt | + | |Pentawatt |
- | |TO-220FP | + | |Heptawatt |
- | |ISOWATT220 | + | |Multiwatt |
- | |TO-247 | + | |Clipwatt |
- | |TO-218 | + | |FLEXIWATT |
- | The kind of insulator (mica, silicone, etc.) isn't specified for these data. | + | The hardware stackup shows only a screw entering the device tab through an optional washer and a bolt on the heatsink side: |
- | A different STMicroelectronics reference (([[https:// | + | {{:electronics: |
+ | ===== Data from other sources ===== | ||
- | However, the maximum torque is slightly contradicted here (emphasis added): | + | ==== Infineon ==== |
- | > Suggested maximum | + | Infineon ran a test on TO-247 packages with torques |
+ | |||
+ | ==== Texas Instruments ==== | ||
+ | |||
+ | TI mentions 50N-cm as the recommended | ||
- | The data given in the table above is the more conservative and therefore preferred. | + | ==== onsemi ==== |
+ | onsemi' | ||
+ | For Power Semiconductors]]. onsemi. Accessed Jan 17, 2024.)) advocates the use of conical " | ||
- | Infineon(([[https:// | + | {{:electronics: |
- | TI(([[https:// | + | 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 |
+ | 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. | ||
electronics/torque_standards_for_power_packages.txt · Last modified: 2024/01/18 02:50 by mithat