Electronics Forum | Mon May 14 17:12:20 EDT 2001 | davef
Continuing along the path that Brian took ... IPC-7525 gives design guideline for stepped stencils. It goes something like: * Stepped area SB GT 25 thou from pads located on the greatest thickness of the stencil * Pads in stepped area SB GT 35 tho
Electronics Forum | Tue Sep 01 19:31:36 EDT 1998 | Kallol Chakraborty
| We are experiencing shorting on a BGA. The part has a 1mm pitch with a 196 I/O count. The problem seems to pop up without warning & disappear in the same manner. | Our pad design is .020" diameter pads with .025" solder resist diameter. The ce
Electronics Forum | Fri Sep 22 09:45:26 EDT 2006 | bradlanger
Greg, All the above. It looked like it was going to be a drop for SNPB HASL at first but after a few thousand boards we started running into all the problems you are describing. We first started seeing non wetting on SMT pads. The solder would wet t
Electronics Forum | Thu Feb 17 10:14:40 EST 2000 | Jim N
We bulid many boards with fine pitch on solder side and then wave. We use a wave fixture that is custom for each board. The fixture covers the SMT components and only exposes the PTH lead during the wave process. It requires about .070 to .100" clear
Electronics Forum | Thu Mar 15 06:26:26 EST 2001 | Sal
Sorry for the lack of information provided, I'll try again : Test Points are the one's that are not soldering. The test points are round in geometry, 0.5MM(metric) in diameter with a HASL finish.The test point are no different to the ed through hole
Electronics Forum | Fri Jun 18 12:50:32 EDT 1999 | jseagle
We currently use HASL on all of our boards and I would like to move to something else. I have sampled some boards with Entek OSP and I loved it, the problem is we have plated mounting holes on just about every board we make. Does anyone have inform
Electronics Forum | Fri Dec 14 10:59:23 EST 2001 | Donald C. Burr
We are considering converting from a water wash wave solder porcess of carbon ink touch pad buttons to a no-clean process. Since the carbon ink buttons are exposed to the molten solder, we are concerned about the residue that is left behind from the
Electronics Forum | Wed Feb 11 09:07:37 EST 2004 | Ashok Thiyagarajan
HI I am currently having a wafer which is stud bumped (Au), I am printing conductive adhesives (with silver fillers) on the pads , and by thermocompression bonding, I am establishing the connnection between. But right now the problem is the silver
Electronics Forum | Mon Jul 11 19:32:27 EDT 2005 | fctassembly
Yes, there have been many issues with the fast dissolution of copper by the SAC305 alloy. In fact, there are companies who have disqualified it for repair operations due to loss/thinning of the pads. SN100C dissolves copper much slower than SAC305 an
Electronics Forum | Tue Aug 22 12:56:29 EDT 2006 | Chunks
Russ is right. The pad in the middle needs to be soldered as well. Also, the ends of leads exposed are not plated as well, so you will never get a toe fillet. Drives our IPC experts nutty, or should I spell it "knutee"? I don�t know, I went to a
