Electronics Forum: solder problem (Page 89 of 507)

Why do some PCB manufacturers reject gerbers due to missing solder masks?

Electronics Forum | Thu Dec 26 20:35:48 EST 2019 | luciano_zhang

I have design some PCBs but last time I met one problem they said missing the solder mask ...any one can give some suggestions why do some pcb manufacturers reject gerbers due to missing sodermask?

16 mil pitch QFPs / solder paste type 4 & 5?

Electronics Forum | Mon Apr 07 13:02:30 EDT 2003 | kmorris

Sorry, I forgot to include the stencil thickness. It is 5 mil. Thanks for the input, everbody. I just checked with our stencil supplier & I thought that Electro-polish was standard with lazer, but I now find out it is not. Our stencil did not get

omit stencil apertures to hand solder or paste, reflow then solder.

Electronics Forum | Thu Feb 27 16:23:37 EST 2020 | dwl

http://www.circuitnet.com/news/uploads/3/Comparing-Soldering-Results-of-ENIG-and-EPIG-Post-Steam-Exposure.pdf Years ago, I battled this problem. ENIG PCBs reflowed with active WS flux. We built one side, and then washed them because they were going

White Hazing under the solder mask of a through hole board

Electronics Forum | Fri Nov 07 12:48:31 EST 2003 | rholland

I have seen in the last couple of months more boards with a white hazing under the solder mask. I ran a few tests on a board to determine the cause of the white hazing underneath the solder mask. First I confirmed, or at least I think I confirmed, t

omit stencil apertures to hand solder or paste, reflow then solder.

Electronics Forum | Tue Feb 25 12:15:42 EST 2020 | dwl

Are you running a no clean process, or are you washing your PCBs? One caveat with ENIG is sometimes washing with hot DI water can effect solderability later on. I would also talk to your solder technicians and see what their preference is. Some pr

How long does it tkae for Tin-Lead solder to rust if put outside

Electronics Forum | Thu Sep 27 17:25:33 EDT 2007 | chef

The short answer is immediately after reflow the problem occurs. To be more exact, what you are describing is not "rust". Rust occurs in iron. The oxidation that occurs in Tin-Lead has been sometimes called "white rust". Either way, oxidation occur

solder joint crack in post thermal cycling test at Dye & Pry

Electronics Forum | Sun Apr 11 11:39:52 EDT 2010 | manchella

When we have sent some of motherboards for reliability testing in a tird party laoratory. It is found that when Dye&Pry is done after 600 cycles of Thermal Cycling, in LGA socket only one of the corner solder joing had 100% type 3 crack. All other so

# of Hours before stainless Wave solder damaged by Lead Free?

Electronics Forum | Thu Jun 30 18:40:06 EDT 2005 | KEN

What your asking has many variables. 1. Material: SS vs. Cast Iron. Iron is thicker. Which SS? 316, 316L 2. Pump speeds, turbulence, hours of operation directly affect equipment life. 3. Things like scraping the pots, the tunnels, impelle

Re: Ghost circuit shorts under smt resisters only when they are located on solder side of pcb (glued down)

Electronics Forum | Mon Jul 26 10:25:12 EDT 1999 | Boca

| | We are having a process related problem with pullup resistors on a controller card which has a I960 micro-processor. | | The controller monitors signal inputs and it's own resources then blinks a LED to indicate its working. The problem is that a

Re: Ghost circuit shorts under smt resisters only when they are located on solder side of pcb (glued down)

Electronics Forum | Mon Jul 26 14:14:51 EDT 1999 | Steve Gregory

| | | We are having a process related problem with pullup resistors on a controller card which has a I960 micro-processor. | | | The controller monitors signal inputs and it's own resources then blinks a LED to indicate its working. The problem is th


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