Electronics Forum | Wed Nov 10 18:02:54 EST 1999 | John Thorup
Hi Dave Sounds like what we call a "squeeze ball". Usually caused by excess paste squeezed over the mask between the pads of the component when placed. This sometimes escapes the pull of surface tension back to the fillet and escapes to the side, us
Electronics Forum | Fri Aug 13 13:38:23 EDT 1999 | Bian Wycoff
| Has anybody adopted the method of stencil printing with the board at a 45 degree angle to the squeegee blade? What are the benefits and drawbacks? I've heard you get better fine pitch results. | | TX | Mark | I have used thetechnique extensiv
Electronics Forum | Sun Aug 02 20:31:22 EDT 1998 | karlin
Hi Bob, The weight of the TBGA is heavier then PBGA due to the Stainless steel heat sink. I have tried run them through the oven without paste. Due to the high lead content( 90Pb/Sn10), the "solder: did not melt. Still see the misalignment issue but
Electronics Forum | Tue Aug 14 21:43:44 EDT 2001 | mugen
Basic understanding, 1) the 2% silver (Ag) gives better shine *joint surface*. 2) Ag improves stength & fatigue resistance of solder joints 3) reduces leech-out of silver from silver-base substrates (eg of such silver-base surface contact: metalli
Electronics Forum | Thu Apr 11 19:06:59 EDT 2002 | tmarc
We are using 1mm pitch BGAs with a great quantity of via(s) under the component. Very shortly we will be placing CSPs with .65mm pitch. Our via(s) are solder masked, however we generally have a percentage of them that the masking is thin enough that
Electronics Forum | Wed Jul 03 10:34:35 EDT 2002 | davef
Suggestions are: * Convince yourself that your paste printing and paste control processes are in control. * Convince yourself you oven is in-control and capable. * Get one of those FREE software packages from the profiler companies [ie, KIC, ECD, etc
Electronics Forum | Wed Aug 21 20:11:34 EDT 2002 | mitch
We are going to begin using a 64 pin 10mm QFP with 0.5mm lead pitch. I was recently asked if we need to purchase our PCB with E3 coating instead of tinned pads when using the .5 pitch. The concept being suggested is that the E3 coating will give us b
Electronics Forum | Mon Aug 09 15:49:16 EDT 2004 | celldude
We have definitely seen money saved. There is a lot less rework after reflow. Money is also saved in overtime. for example...when we are building a first article board with many placements, it is not always possible to get the first board through the
Electronics Forum | Fri Sep 24 12:20:58 EDT 2004 | Simon UK
Hi there, I have been using DEK's of all types over the past 9 years, with a few SMTech's and MPM's thrown in for good measure. I personally would recommend using DEK, they may seem expensive, but i find that worth the cost with the good support we
Electronics Forum | Wed Jan 05 08:58:13 EST 2005 | davef
Q1. Is it enough to use only water while cleaning or is it necessary to use any additional chemistries and/or saponifiers as well? A1. It depends on: * Flux residues that you're cleaning * Standoff of the components * Cleaning technology [we've neve
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