Electronics Forum | Mon Apr 30 09:20:50 EDT 2001 | Steve Zanola
We have seen the same thing. Our vendor recently change the way the BGA is fabricated and the new package warps. We are currently trying to adjust our process paramentes to fix this problem. I will try the "bake out" suggestion and see if it cor
Electronics Forum | Tue May 13 08:26:29 EDT 2008 | davef
First, on your reflow temperature comment: The 183*C focus for reflow recipes for tin-lead solder is a falicy. If you held a recipe for tin-lead solder at 183*C peak, it would never reflow. Recipes for tin-lead solder need to be at liquidus plus 20*C
Electronics Forum | Tue Dec 26 12:35:09 EST 2000 | Dave F
Your English is fine. Your assessment that corrosion on a portion of the metalization on the end of a component is causing the tombstoning is reasonable. We've seen that before. Corroded components received from a supplier is not acceptable as an
Electronics Forum | Thu Nov 16 18:19:10 EST 2000 | Dave F
We want to improve our process for accepting SMT solder paste stencils received from suppliers. Our process: * E-mail CAD aperatures to supplier with "readme" giving specific fabrication instructions to the supplier. * Receive stencil from the suppl
Electronics Forum | Wed Oct 01 22:15:36 EDT 2003 | davef
Tough to say. It depends on the type of solder mask, the producer of the solder mask, and your board fabricators' process. As one angle on this, solder mask type affects thickness. Minimum clearance: * Liquid photoimageable: 2 thou * Screened liq
Electronics Forum | Thu Aug 10 13:36:48 EDT 2000 | Bob Willis
I recently have been examining multilayer board failures. They are the classic inner connection failure between the foil and the through hole plating which I have not seen in many years. Has any one experienced any issues recently specifically relati
Electronics Forum | Thu Feb 18 12:56:18 EST 1999 | Bob Barr
We are using .040" diameter fiducials (global and local) on our boards. They are solder covered and HASL. I get batches of boards where the p&p vision system has trouble reading the fiducial. The fiducial looks dark on the screen. The board vendo
Electronics Forum | Sun May 24 06:02:33 EDT 1998 | Earl Moon
| Hello, | I am looking for suggestions for cleaning pcb's after the routing (fabrication) process. Keep in mind that these pcb do not have components intalled on them yet. | We have considered pre-drilling the routing plunge points, but cost and ca
Electronics Forum | Tue Feb 26 10:55:58 EST 2002 | davef
This could be an electroless nickel / immersion gold specification. While the symmetry of the numbers is pleasing to the eye, but as Joyce Marchand says, "It doesn't blow-up my skirts." Problems with your specification are: * Lower end of the gold
Electronics Forum | Thu Apr 18 16:52:15 EDT 2002 | davef
General comments are: * First place I would look is the supplier of the pins that you are trying to install. Most suppliers that sell press fit components have done a good deal of work to qualify the component and will have all the specifications yo
