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J-STD-003

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MEO

#68225

J-STD-003 | 15 February, 2013

Hi, We are having a problem with the interpretation of the surface evaluation criteria of J-STD-003 section 4.2.2.4.2.

"A minimum of 95% of each of the surfaces (i.e. each pad) being tested shall exhibit good wetting. The balance of the surface may contain only small pin holes, dewetted areas, and rough spots provided such defects are not concentrated in one area."

Some are thinking it means 100% of the pads must be wetted at 95% or better.

Other are thinking it means 5% or less of all the pads can show imperfections.

What do you think is the right interpretation?

Thank you!

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#68227

J-STD-003 | 15 February, 2013

I'll throw my hat in the ring that says, "At least 95% of the pads must be properly wetted."

BR, davef

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#68228

J-STD-003 | 15 February, 2013

My hat in the ring too, but with ALL pads showing 95% coverage or better.

Slightly different interpretation!

'hege

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#68251

J-STD-003 - All Must Be 95% Or Better | 20 February, 2013

From IPC APEX ... Hege is correct ... ALL pads have to be 95% wettable or better.

BR, davef

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MEO

#68305

J-STD-003 - All Must Be 95% Or Better | 25 February, 2013

Thank you guys! I will use this interpretation. However it is hard to meet when using the wave method.

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#68311

J-STD-003 - All Must Be 95% Or Better | 26 February, 2013

If anyone still disagrees with you point, out that the "of each" refers to individual pads. If the 95% refered to 95% of the pads it would not have said "of each".

Also someone correct me if I'm wrong but isn't this standard to do with solderability (i.e. acceptability) of the raw PCBs not the final assembly? So if there is a problem then it's to do with the board shop and/or storage of the PCBs.

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