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Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


SMT Process

Malcolm Jussawalla

#7329

SMT Process | 23 July, 2001

Hello,

I am new to SMT and I was wondering if someone could give a breif overview of a generic SMT process. Basically what machines are needed and how chips are mounted. More specifically, how the solder is applied.

Thank you

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Malcolm Jussawalla

#7331

SMT Process | 23 July, 2001

Hello,

I am new to SMT and I was wondering if someone could give a breif overview of a generic SMT process. Basically what machines are needed and how chips are mounted. More specifically, how the solder is applied.

Thank you

This message was posted via the Electronics Forum @

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Charlie

#7336

SMT Process | 23 July, 2001

Depending on how interested you are get a hold of Ray Prasad book "Surface Mount Technology, Pricniples and Proctice."

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monkey

#7339

SMT Process | 23 July, 2001

In brief, most companies have a board loader, a screen printer machine, various part placement machines (usually at least one chip shooter for small parts and one for fine pitch and larger components), and then a reflow oven. (inspection equipment is optional but often a part of a smt line).

The board gets loaded into the screen printer where paste is applied via a squeegee over a stencil that is made from your CAD data. Paste is deposited onto the pad (4-6 mils thick) as the squeegee cycles over the stencil.

Next, the pcb travels to the part placement machines where the parts are placed on the solder paste. Next, it goes into the reflow oven where the paste heats up, reflows, and solidifies forming a strong joint. (you hope...)

This month's issue of SMT magazine has a special section called: The Building Blocks: A Step-by-Step Guide to Surface Mount Technology. Very good, basic analysis. You can subscribe for free at http://www.smtmag.com, and they have most of the information online.

There are a lot of resources out there, so it shouldn't take too long to get a basic understanding.

Hope this helps! N

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#7344

SMT Process | 23 July, 2001

Prasad�s book, that an earlier poster mentioned, is good, but other books to consider are: * MacLeod Ross �Guide Design & Manufacturing V1 & V2� Electrochemical Publications * Wassink & Verguld �Manufacturing Techniques For Surface Mount Assembly� Electrochemical Publications * Look at the SMTA bookstore for other suggestions.

Mr. Prasad [http://www.rayprasad.com] presents one of the better �Introduction To SMT� courses. Go to a �SMT Boot Camp� [eg, SMTA, EMPF, NTCu, etc.].

Use the fine SMTnet archives.

Cookson recently sent us a disk on a three level web-training program. We have not broken the seal on the disk.

Continuing with an earlier poster�s comments, �COMPLETE SMT STEP-BY-STEP SERIES. Now in one place is SMT's entire 2000 Step-by-Step Series that maps out the complete SMT process in 10 steps. Even for industry veterans, this series can serve as a resource that explains in detail the different aspects of SMT.� [http://smt.pennnet.com/Articles/Article_Display.cfm?Section=OnlineArticles⊂Section=Display&PUBLICATION_ID=35&ARTICLE_ID=103095]

Find and lookit �Terms & Definitions� in the SMTnet Library

Hand soldering: http://www.epemag.wimborne.co.uk/solderfaq.htm] [http://www.gtscomputers.com/psxmod/howto.htm] [http://metcal.com/tips/1.3.1.htm]

Peruse trade journal [eg, SMT Magazine, Circuits Assembly, Electronic Packaging & Production, etc.] sites

Applying solder paste: * [http://www.heinc.com/amtech/smt.html#printing] * EMPF [http://www.empf.org/html/empfasis/current.html] posted an Empfasis article on printing within the past 6 months

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