Electronics Forum | Tue Feb 01 04:11:58 EST 2000 | emmanuel
I am to assembly a power SO on the top side of a double side board. My designer has implemented a lot of thermal vias in the heat sink pad of this component. The problem is that i need to prevent the solder cream from polluting the bottom side of the
Electronics Forum | Mon Mar 25 21:50:10 EST 2002 | davef
Some of this was copped from Fred. There are numerous package types that now fall under the rubric of land grid array [LGA]. Land grid devices [ie, Bumped Chip Carrier� [BCC], LGA, Quad Flat-pack No-lead [QFN], MicroLeadFrame�, etc] are essentially
Electronics Forum | Thu Sep 03 22:03:32 EDT 2020 | SMTA-64386139
Both conditions are acceptable for this bottom brazed flat pack package. The solder coverage must be within 0.070 inch of the lead/package interface per MIL-PRF-38535, paragraph A3.5.6.3.4.a. While that requirement could allow for a gold gap near t
Electronics Forum | Mon Dec 27 05:16:17 EST 2021 | jineshjpr
Hi Stephen, Thanks for your response. Since the OSP Finished PCB to be execute in mass volume, almost 3 to 4 weeks (Vacuum Sealed Pack) takes place prior to assemble. Although we are using SnPb 63-37 Type 4 solder paste for this single sided SMD asse
Electronics Forum | Mon Jan 14 22:52:48 EST 2008 | davef
Using larger pads on the corners is fairly common to improve self-alignment of BGA and CSP. For example, "9.3.2.8 Large corner pads and overprint The self-alignment of BGA or CSP can be improved through a design change. By utilizing a large board pad
Electronics Forum | Tue Feb 01 06:54:19 EST 2000 | Roni H.
Hi, Does anyone have experience with gold over nickel (electroless) PCB finish: - Repeatble quality from PCB mfg. (very "painfull" with ENTEK). - Environment condition sensitivity. - Thermal processes sensitivity. - Solderability (Reflow & wave). -
Electronics Forum | Tue Feb 20 16:51:22 EST 2001 | davef
You should evaluate products from Datapaq, Electronic Controls Design, and Kic Thermal Profiling. Each sells very good reflow profiling equipment. Beyond the straight forward issues surrounding the question of "Does this thing produce a good profi
Electronics Forum | Wed May 22 19:10:47 EDT 2013 | anvil1021
We do a lot of these devices and I guess I am not familiar the term "Dry Solder". The QFN device is not designed to have a drain hole, but needs to have thermal vias to control heat in most cases. We have used every possible gnd pad design and modifi
Electronics Forum | Fri Aug 30 16:25:21 EDT 2002 | davef
Imm silver holds-up to multiple thermal cycles very well. The things, we guess, are happening to make imm silver tough to solder after heating and sitting are: * Oxidation of the silver. * Reduction of the co-deposited organic anti-tarnish [used in
Electronics Forum | Sat Jul 28 08:37:52 EDT 2007 | davef
There is no good choice. Board Finishes: Industrial/Battelle Class 3 Environment [Reliability Knowledge Gaps: For use of Pb-free solders in High Reliability Applications, J Smetana, iNEMI Availability of SnPb-Compatible BGAs Workshop, March 1, 2007,
