Electronics Forum | Fri Jun 10 19:05:23 EDT 2022 | llawrence
Overprint, that is putting extra solder on with the stencil that is even further out from the pads, with the idea that it will suck that solder up during reflow? I could give that a try. Are there any general recommendations when overprinting? And wh
Electronics Forum | Fri Jun 10 23:24:02 EDT 2022 | llawrence
Ah okay, that should be pretty easy to do on the current board design. If overprinting doesn't work, then I might try a preform. I wasn't even aware that was a thing, I might be able to do some of our through-hole components that way if they are rate
Electronics Forum | Sat Dec 16 10:03:32 EST 2000 | Dave F
Castellation. A recessed metalized feature on the edge of a leadless chip carrier [LCC] that is used to interconnect conducting surface or planes within or on the chip carrier. If you search the fine SMTnet Archives, you find: * A fine thread [cast
Electronics Forum | Fri Dec 27 14:27:40 EST 2019 | slthomas
We switched to a REL0 T3 paste, Amtech LF-4300. It wets the castellations more consistently. I believe that in our case it was more of a plating wetting issue with the parts, but yours sounds more like a pcb finish or thermal issue. That larger pad
Electronics Forum | Fri Jun 10 19:22:59 EDT 2022 | jdengler
Yes. We only do the side not under the component and do 25 mils if there is enough room. A solder preform is simply a block of solder that is shaped like a SMT component and comes in tape and reel. Most solder manufactures offer these. You can ta
Electronics Forum | Tue Jun 14 14:57:29 EDT 2022 | glasscake
Check for warp during reflow or placement, if your board is bowing you are not going to make a good solder connection. If your board is warping during reflow you may need to make a currier to support the board during reflow if using the edge to tran
Electronics Forum | Wed Feb 10 18:26:04 EST 1999 | Earl Moon
| Has anyone had any experience in using SMT to mount an organic (FR-4, Getek) rider card onto an organic (FR-4, Getek) mother board? By SMT I mean the attachment of the rider card would be through pads directly to pads on the mother board. | | Than
Electronics Forum | Wed Jul 31 14:08:22 EDT 2002 | Dave G
Used this paste on ENIG boards W/O N2 and had very good results. (0402's,BGA's,16mil FP) Never had the need to use N2 with this paste on our products. Running with N2 shouldn't hurt anything. The wetting properties should get even better than they ar
Electronics Forum | Wed Dec 27 08:11:46 EST 2006 | billyd
Thanks dude. It's a bit tough, but I guess so long as it's well thought out, it's like anything else. I shoot for a 60% coverage, pre reflow, with the vias either filled with epoxy, or capped with mask, at least if the plan is to use the thermal pad
Electronics Forum | Wed May 20 17:56:51 EDT 2009 | dyoungquist
I have attached a pdf showing the dimensions for the QFN we placed. First, The pins on the part are not only on the bottom side but also wrap around to come up each of the 4 sides of the part as shown in the side view in the attached pdf. This i
