Nippers / Cutters for FR4, for separating PCBA out of carrier frame? - Page 1
Forum section: electronics / general

author: smoothVTer
author_rank: Regular Contributor
timestamp: September 27, 2018, 04:02:21 pm
content: Hi Everyone!I'm wondering if anybody has any suggestions on the best way to cut out a PCBA, or more specifically a rigid-flex PCBA, out of its retaining frame. My PCBA has a very irregular shape with many radiused inside and outside corners, arcs, and small small rigid off-shoots connected to flex. Imagine something like this, but with many more flex sections coming off into many more rigid sections:There are mouse-bites on all over my PCBA outer edges, holding it to the frame, similar to the above photograph. It is not possible to twist out all pieces of this PCBA by hand because it would rip and/or put stressed on the flex parts, some of which are only 2mm wide. For the time being I've been using some Hakko flush-cut pliers intended for copper wire, and that sort of does the job, but leaves a very rough edge and creates micro tears in the FR4. It also wears the metal of the cutters fairly quickly.The other consideration is that the space between the PCBA and carrier frame is 1/4" or so. Any kind of hand cutters or nippers would need to fit in between this 1/4" gap, and be able to cut a straight line in the FR4.Are there any standard tools for cutting out PCBAs from their carrier frames, other than the flush cutters I already described? That can (a) withstand 1000's of cuts through FR4 (b) leave a rather clean edge (c) not cost $10000?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 27, 2018, 04:30:11 pm
content: Add extra slots & mousebites to the waste so you can snap it off in sections.You can also put snap-out tabs like thishttps://youtu.be/kLKSon2GnY0?t=932

author: SeanB
author_rank: Super Contributor
timestamp: September 27, 2018, 04:31:53 pm
content: Nice cutting board ( bamboo probably as it survives well, and is non static) and a Stanley knife along with a box of the blades. Otherwise you are into the realm of having bespoke punch and die sets where the appropriate points are the cutting edges, and it pops the whole thing out as a unit, after you place the full board into it and get the alignment pins you made as part of the frame right. Or how are you for a mini CNC mill and some small carbide milling cutters and a screaming speed spindle, along with a base board ( particle board like Masonite or chipboard) that has both a sacrificial aspect ( it handles the cut through part) while also having some polished die pins to hold the board in place while cutting.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 27, 2018, 04:33:07 pm
content: There are also purpose made tools like thesehttps://www.somersetsolders.com/manual-pcb-depaneling-tools/p10https://www.ebay.co.uk/i/252179964778?chn=ps&var=551916297452Though these do need enough length of straight slot to get the head into, and enough component-free space at the sides of the slots

author: electrolust
author_rank: Unknown
timestamp: October 01, 2018, 10:08:22 pm
content: hakko makes some nice cutters, in various sizes. they do leave a "cut" edge, if you need a smooth "machined" edge you'll need to file it down afterwards.

author: langwadt
author_rank: Super Contributor
timestamp: October 01, 2018, 10:15:27 pm
content: https://www.olamefusa.com/e_depanelers.htm

author: Delia
author_rank: Newbie
timestamp: October 15, 2018, 12:37:44 pm
content: The PCB factory did not make well about the outline.

author: Mattylad
author_rank: Regular Contributor
timestamp: October 18, 2018, 08:38:20 pm
content: Just by the break off tabs, make the route path so that it nips into the border a little more so you have room for the cutters.I.e turn 90 degrees outwards for about 3mm+

author: kkritsilas
author_rank: Contributor
timestamp: October 21, 2018, 12:25:41 am
content: We used to use a very small router bit with an automated router head when I was in manufacturing. During NPI (before board outline was completely settled and the automated router head was programmed), we used a Dremel with a small dismeter router bit, or a Dremel with a flex shaft and a cut off wheel, depending on board layout.If possible, and if this under your control, try to use scoring vs. “Webs”. The scored boards always have a clean edge (if done properly) and never have the problem of the substrate delaminating if somebody tries to twist the cracker/carrier section off.

author: Nusa
author_rank: Super Contributor
timestamp: October 21, 2018, 07:06:51 am
content: I suspect a cheap wood chisel and a mallet on a wood surface would work fairly well.