Electronics Forum | Mon Nov 07 16:34:55 EST 2005 | CW
If I am putting chip capacitors on a .063 FR4 board, what size package should we stay away from to avoid cracking? If I use 2 mil copper on the outside layers of a PCB, am I limited to what pitch of parts I can use? Specifically, will using 0603
Electronics Forum | Thu Sep 19 23:46:23 EDT 2013 | action_101
Reliability, number of machines in the field, you can pick up an older UIC GSM and it can easily handlrle 0603's and up. On top of that, any fine pitch or bga's and you'll be fine. Plenty of feedets out there too. Manncorp is as low as u can go. Very
Electronics Forum | Fri Oct 22 11:37:38 EDT 1999 | Brett Gordon
Working DFM SMT issues with respect to a client's artwork together with a heavily modified solder stencil, I was able to reduce 0402 tombstoning from 80% across the board to 3%. I winged the aperture reductions, but are there any "rules" or guidelin
Electronics Forum | Tue Nov 09 17:12:38 EST 1999 | Dave F
Steve: Addressing your points: 1 FINE PITCH APERTURES Electropolishing Laser Cut Stencils: Laser cut should not requiring polishing. Geesh, how much money do you have for stencils? ;-) Oval Shaped Apertures: Pass. What do you expect to gain f
Electronics Forum | Mon Nov 07 11:26:23 EST 2005 | CW
How large of chip capacitor can we use reliably? I��ve heard they tend to crack. I��ve also heard if you pre heat the larger chip caps (1812 and above) before vapor phase reflow, they won��t crack. If I use 2 mil copper for a power supply board, a
Electronics Forum | Sat Nov 13 14:09:45 EST 1999 | se
First, let me say what I always say: a good chem-etched stencil will print fine pitch. Chem-etch brings trap to the side walls because its a physical by-product of the process. Because they are less expensive you can add electropolish and still save
Electronics Forum | Wed Mar 24 23:12:48 EDT 2021 | grahamcooper22
0.66 area aspect ratio...so for example...if the device is 0.5mm pitch QFP, the pcb pad may be 12 thou wide..make the aperture 9 to 10 thou wide...and reduce it's length by 10 % overall compared to the pcb pad.... Depending on device pitch, select ap
Electronics Forum | Thu Mar 25 20:50:50 EDT 2021 | stephendo
A couple more things. The PCB. What size are the pads? One time a board shop had difficulty putting masking between the pads of a QFP and the pads suffered as a result. When I told them they didn't have to have masking between the pads, the pads w
Electronics Forum | Thu Mar 25 23:23:00 EDT 2021 | llawrence
The QFP pitch is 0.5mm. Pad size is 1.475 x 0.3mm, and the new aperture size is 1.32 x 0.22mm. I'm not sure about whether or not it is lasered, but on the newly ordered stencil I selected the polishing option. Looks like the pad width is already 2/3
Electronics Forum | Mon Nov 07 16:31:47 EST 2005 | CW
hi Bob, Thanks for the info. I understand your comments, but I am looking for specific guidance, If I am putting chip capacitors on a .063 FR4 board, what size package should we stay away from to avoid cracking? (I realize this is dependent on h
