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QFP wetting

Views: 2181

#52455

QFP wetting | 12 November, 2007

Hi, ALL

I experience some QFP with wetting issue on the heel of the lead. There is no fillet wetting on the heel which causes reject bt the customer, but not all the QFP. Could anyone pls help what is the causes of this problem, it is due to oxidation, insufficient solder or plating issue.

Thanks

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RDR

#52462

QFP wetting | 12 November, 2007

Could be any one of the 3 you mentioned, need some details here, do you really think we can answer this question as it is?

Now for your issue,

what is the make up of the lead itself on the part?

what is the reflow profile at this part?

what is Paste type?

what is stencil thickness?

What pitch component?

R

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#52471

QFP wetting | 12 November, 2007

i will supply dah 3d chart to sol the problem foryou

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#52486

QFP wetting | 12 November, 2007

Hi,

Thanks. Waitng for your reponse. BTW, if I were to perform a test as below will this give me some result to indicate if the component is defective.

1) Print solder paste on plain PCB without copper track. 2) Mount the QFP & reflow 3) If the solder wet on the lead means good component lead 4) Solder do not wet on lead means bad plating or oxidize

Thanks Rdgs...

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#52509

QFP wetting | 13 November, 2007

We'd add poor thermal recipe development, focusing on some QPF but not others that may a have a peculiar plating that requires extended time above liquidus.

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