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PIHR... what do you think...?

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#72225

PIHR... what do you think...? | 9 June, 2014

Hola...

I'm in the middle of a project to reduce assembly time in one of our products, this product has a lot of TH connectors to be soldered by hand, I'm implementing PHIR, first run has been completed, the appearance of the solder joints are obviously different compared with hand soldering... do you think this solder joints are acceptable? do you think the flux residues are normal? I'm planning to run a test using solder pre-forms, the standoff height of the components seems to be Ok for this pre-forms, what recommendations can you provide based on the attached images? The assembly uses SAC305, ENIG, 1.6mm thickness, 0.005" stencil...

Saludos!

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#72226

PIHR... what do you think...? | 10 June, 2014

Your bottom-side joints look deficient in solder. It appears that less than 50% of the land area is soldered.

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#72227

PIHR... what do you think...? | 10 June, 2014

It is very hard to say by looking at picture(solder joint quality).Overall appearance looks good.If you think is not sufficient solder or meeting required standard, enlarge opening of connector on solder stencil. Make all conn. aperture square or increase diameter. What class product you are building?

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#72230

PIHR... what do you think...? | 10 June, 2014

this is a Class II product.

If I increase the openings... will I have random solder balls?

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#72231

PIHR... what do you think...? | 10 June, 2014

Probably not considering you have ample volume left on your land area for more solder.

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#72259

PIHR... what do you think...? | 12 June, 2014

What you need here is a double print process. You should have 5mil stencil for SMT followed by a 10-15mil stencil for TH. I don't know what quantities you are running or do you have the capability to add another printer in the line, but that would be your best choice. These joints don't look good and I don't think are acceptable for class 2 product.

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#72260

PIHR... what do you think...? | 12 June, 2014

No, is will not create random solder balls. I have experience doing this(When we had a big via in middle of filter cap which was sucking all solder ,leaving insufficient solder for a joint).I calculated volume of via hole to determine the expansion of solder screen aperture.

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#72264

PIHR... what do you think...? | 12 June, 2014

Update 6/12

After solder preform (SAC303 0603) I did not get good result... Couple of connectors have a guide pin that does not allow enough space for preform :(

I will try with aperture size modification for my next run.

What about step up stencil? I have added tape under the stencil close to the apertures and I'm getting better results, I have a couple of QFPs but far from TH Connectors, tapes seem not to affect them...

Saludos

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#73037

PIHR... what do you think...? | 9 November, 2014

Just thought it may be helpful, my FREE 100 page ebook on Pin In Hole Intrusive reflow is available to download see http://pihrtechnology.com/

Also my book on Package on Package may also be useful for the future see http://www.packageonpackagebook.com/

Bob Willis

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#73044

PIHR... what do you think...? | 10 November, 2014

Hola Bob, in fact I made the proposal for the PIHR just after review your e-book, it helped a lot!

Gracias!

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