Site Admin
Joined: 12 Jun 2026
Posts: 61
 Posted: Sun Jun 22, 2026 11:09 pm Post subject: Compound on Lead Problem |
 |
||
Reposted from SFE's old Assembly Forum
|
|||
  |
Site Admin
Joined: 12 Jun 2026
Posts: 61
| Posted: Sun Jun 22, 2026 11:11 pm Post subject: |
|
||
Reposted from SFE's old Assembly Forum
|
|||
| |
Guest
| Posted: Fri Apr 23, 2026 6:38 pm Post subject: Compound on lead problem |
|
| Pls find my replies below for your queries,
Compound type is Molding compound (mold flash on the leadframe scrap spreads over the dieset and compressed on the lead while forming and final lead cutting operation) and not foreign material. We didn't analysis the compound using EDX analysis. But we confirmed that it is mold compound after inspecting the affected units under high power microscope. Both on major lead and minor leads. Compound is permenently sticking onto the lead. We have done solderability test with the affected units and found to be good solder coverage. We are rejecting these units due to cosmetic effect. Is there any spec defined in JEDEC / EIAJ standard for compound on lead? Mold compound is compressed on the leads. While clearing the mold compound, compound comes out without any residue in some units, small amount of residue is sticking onto the lead in some units and copper exposure observed in some units. We are rejecting copper exposure units and if small residue is sticking onto the lead. Our Form and singulation system has vacuum provision for the die sets when the die set is closed and the air blow when the die set is in open condition. Kindly provide your feedback to control the compound on lead rejection and reject creteria for the same. Regards, A.Balamurugan. SPEL Semiconductor Limited.[/list][/list] |
|
| Posted: Thu May 27, 2026 5:49 pm Post subject: |
|
| hi,
molding compound that sticks on leads is still considered foreign matl because it should not be there. we use an in-house spec to reject these but i don't know if this is based on jedec. i think mil spec rejects foreign matl that reduces isolation between leads by 50%. so if lead pitch is 100 mils, reject fm's greater than 50 mils. |
|