Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Scored Printed Circuit Boards

Russ Cutler

#7420

Scored Printed Circuit Boards | 26 July, 2001

We are looking into using Scored PWB's on a new high volume design. We've used Tab Routed PWB's exclusively in the past. I understand that Scored PWB's are more efficient to produce and depanelize.

Question: What are the industry standards for creating a panel drawing for a Scored panel of PWB's...for example do you specify on the panel drawing to cut 1/3 deep from the top and 1/3 from the bottom, leaving 1/3 thickness remaining in the middle of the PWB?

What other dimensions are needed? I will include a frame around the entire PWB that has fiducials and tooling holes for ICT.

Anyone have any thoughts? Please let me know, and Thanks!

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#7423

Scored Printed Circuit Boards | 26 July, 2001

You're correct. Check the fine SMTnet Archives to get started. Look in both the "design" and the "production" conferences.

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Chip Gill

#7525

Scored Printed Circuit Boards | 1 August, 2001

I read your request for design information on panel layout for V-scoring, and felt the need to respond.

Scored PWB's are indeed more efficient to produce and depanel than tab routed PWB's, but there are also drawbacks associated with this method.

The main drawbacks include, 1) Score lines weaken the panel, so if you have a large panel a/o heavy components, you may need stiffeners on the leading and trailing edges of each panel as they move through the process to avoid premature breakage along the score lines, 2) Pizza wheel cutters are inexpensive, but blades can be costly, 3) Depaneling is then limited to a manual or semiautomatic process, and 4) Whether the panels are hand broken or separated using pizza wheels, you can have major quality problems damaging solder joints and components.

Number 4 is by far the biggest drawback. Email me for more information and some documented horror stories.

If you have a very high volume application you may also want to consider sawing as your depaneling method. It is fully automated, eliminates scoring from the bare board supplier, requires little more bare board real estate than scoring, imparts virtually zero stress to the assemblies, and is much faster than tab routing, pizza cutting, or hand breaking.

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Chip Gill

#7527

Scored Printed Circuit Boards | 1 August, 2001

My email address is chip.gill@ipte.com, or hit our website IPTE.com.

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John

#17168

Scored Printed Circuit Boards | 10 August, 2001

We use scored boards almost exclusively on our new products, but there are some things to be aware of. 1) If it has SMT on it, hand breaking it is a bad idea (our customers refuse to discuss it). 2) Pizza cutters are a bad idea (our customers should have refused to discuss it). 3)It can be done well with the right equipment. Contact Pioneer Dietecs. They have a very slick semi-automated system that the operator only has to load and unload. It cost more than a pizza cutter, but there was a huge labor and quality savings. Also, check out the archives, I believe Dave F posted a substantial list of singulation equipment suppliers a few months ago.

Hope this helps, John

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