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Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


PCB finishing

PeterB

#4443

PCB finishing | 13 April, 2000

We are a small/medium contract manufacturer and like most we do our best to ensure that PCB's we process are panelised to ensure efficient throughput and good quality results.

Sometimes however we are stuck with free issue PCB panels supplied by some of our customers that are not laid out or panelised as we would like. These are nearly always routed, with pips left along at least 2 of the PCB sides. Also it is normally the case in this situation that the remaining pip material that is left after breaking out of the panel must be removed to ensure the circuit fits into its enclosure.

We are unable to invest in auto depanelling kit because of the infrequent nature of this problem and the product variety.

Does anyone out there have knowledge of equipment available for finishing the PCB edges, other than using a file or linishing?

best regards,

Pete B.

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#4444

Re: PCB finishing | 13 April, 2000

Pete: What�s a "free issue PCB panel"? Is that like "consigned material" here in the states?

In response to your question, several possible approaches (in no particular order): 1 Router approach: 1a Wood working router * Go over to Sears and buy a router, a bit, and a Hoover attachment. * Drill a hole in your bench. * Bolt the router to the bottom of the bench with the bit showing through the hole an eighth inch or so. * Bolt a piece of wood top of the bench to act as a break. It would be positioned: - Centered on the bit side to side. - Front vertical edge lined-up with the cutting edge of the bit. * Attach the Hoover thing to the break and to your shopvac so it can suck-up the nasty bits (nasty bits, not not naughty bits. Get your mind out of the gutter.) that�ll otherwise end-up dusting your whole shop. 1b Similar to 1a above, Dremel makes a "stand" with a break ($45) to hold your Dremel tool in-place. (See p137 in Technitool #71) 2 Automated file approach: Bag the silly holder and use a Dremel tool with an abrasive bit to buff-down the pips. 3 Scoring depaneler approach: Either 3a Buy ($10k) one of those scored board depaneling rigs from: Radoll Designs 912.228.0200 Andy National Airborne Technology 604.763.2232 fax762.3374 Donna Bellamy Electronic Precision Technology 617.928.3400fax0840 FKN Systek, Waltham MA 617.642.6820 CAB Technology Westfield, MA 978.392.3459 fax 3601 3b Buy a blade for scoring depaneling rig from one of the above companies and gin-up a way to mount the blade to meet you purposes. 4 Nibbler approach: Several companies (ie, Streamline Automation streamlineautomation.com, CAB) make "nibbler" tools that cost about $1k

Good luck Dave F

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PeterB

#4445

Re: PCB finishing | 14 April, 2000

Dave,

'Free Issue' here in the UK means material (be it PCB's or anything else) supplied by our customer from their stock and not charged to us. That is why we sometimes cannot control the design parameters.

Many thanks for the suggestions. We already use 'Nibbler' approach for routed panels also some of your suggestions for scored panel separation.

Was hoping not to have to construct my own machine but will try a combination of the Dremel and vacuum attachment approach if all else fails. This will hopefully not have too much impact on the naughty bits!

regards,

Pete B.

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#4446

Re: PCB finishing | 14 April, 2000

Peter: Whatever you do, do not affect the naughty bits.

I'm aware that some of my suggestions applied to scoring, but you'll find, I believe, the those scoring machines will work swimmingly on routed boards also.

Cheers Dave F

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Keith Stone

#4447

Re: PCB finishing | 20 April, 2000

Hi Pete

We have a Black and Decker Power File and have mounted it on a bench in an enclosure to capture the hazardous dust. We used a hopper (usually used for guttering!) with a wire mesh over the top (static reasons) mounted in the bench top inside the enclosure connected to a vacuum cleaner. Operators have to wear a mask for Health and safety as well as goggles and rubber gloves :) he he!. The power file throws the dust forwards, gravity aided, into the hopper if you use the top side of the file, rather than into your face if you use the bottom side as designed. This process does create a bit of dust on the board which you will need to brush off over the hopper. The vacuum cleaner would be better replaced with a proper extractor / filter but these are expensive. Best of all is to persuade your customer(s) to change the breakout design so they are sublush. But I am sure you know that!

Regards

Keith

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PeterB

#4448

Re: PCB finishing | 20 April, 2000

Keith,

Many thanks for your contribution. We are already rigging something up very similar to your suggestion! I note the comment about the rubber gloves with interest :-)

Re: the design issue, in an ideal world all customers would heed your advice but you know what they can be like from time to time!! (they are always right of course).

All the best,

Pete B.

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