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Solder ball specifications?

Joe B.

#18717

Solder ball specifications? | 24 January, 2002

Are there any formalized standards for the properties of solder balls?

Example properties: sphericity uniformity(variance) of the ball size distribution surface roughness surface oxidation or other surface treatments/contaminants ??

As someone relatively new to the SMT industry, I'm also wondering if certain sizes and compositions are popular or desired, or used as standard sizes in smt designs. Are there any good references for such things?

Thanks, -JB

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#18720

Solder ball specifications? | 24 January, 2002

Are there formalized standards for the properties of solder balls? No

Get IPC-7095 �Design & Assembly Process Implementation for BGA's�.

General comments about array package solder balls are: * Ceramic packages use harder solder, like 90/10. * Plastic packages like softer solders like 60/40. * Size and pitch of the package influences solder ball size.

JEDEC focuses on package outlines. JEDEC has issued several BGA-related specifications. These include: MO-149 - Tape BGA / square MO-151 - PBGA / square MO-156 - Ceramic BGA / square MO-157 - Ceramic BGA / rectangular MO-158 - Ceramic column Grid Array / square MO-159 - Ceramic Column Grid Array / rectangular MO-163 - PBGA / rectangular

I can't say one way or the other if these specifications go into the type detail you seek.

Look for a review of �Area Array Packaging� by Ken Gilleo in the SMTnet Newsletter within the past couple of months.

Just out of curiosity, what is the point in trying to understand this information? Frankly, most of us are just glad when the packages have all the balls attached and that they solder.

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Joe B.

#18738

Solder ball specifications? | 28 January, 2002

Dave F, thank you for your reply and the references you included. You asked why I'm trying to understand this info, here's an answer: I'm working on an NSF-funded materials-related project, one aspect of which may lead to some advances in the formation of solder balls and powders, allowing significantly better control and smaller variance on some of the properties I mentioned. Measuring success on this aspect of the project would be aided by knowledge of the solder ball properties (including preferred ball sizes for the different size packages) desired by the users of solder balls.

Related to your comment about solder composition, I was under the impression that solders containing lead were gradually being phased out, with a range of alternative compositions proposed as replacements. Is this correct?

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#18743

Solder ball specifications? | 28 January, 2002

Sounds like an interesting project.

In Euroland and Japan, there are political moves with no scientific basis afoot to exclude lead from electronic products. There is a HUGE body of knowledge on the topic. For instance, Electrochemical Publications recently published "Environment-Friendly Electronics: Lead-Free Technology" by Jennie Hwang

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#18747

Solder ball specifications? | 29 January, 2002

On his site "SMT In Focus", our friend Brian Sloth Blitzen lists the following sampling of lead-free [no lead] links: * Alpha Metals: http://www.alphametals.com/lead_free/index.html * Circuits Assembly magazine: http://www.circuitsassembly.com/db_area/archives/leadfree/index.htm

* IPC: http://www.leadfree.org * Soldertec: http://www.lead-free.org * NEMI: http://www.nemi.org/PbFreePUBLIC/ * National Physical Laboratory: http://www.npl.co.uk/npl/ei/iag/leadfree/index.html

* National Physical Laboratory: http://www.npl.co.uk/npl/ei/research/leadfree.html * Indium Corporation: http://www.pb-free.com * Soldering Technology Centre: http://www.solderworld.com

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