Electronics Forum | Mon Oct 21 11:49:20 EDT 2002 | sueph
Mike, We are currently wave soldering several assemblies with with a lot of ground plane. The soldering handbook we have in house suggests a preheat temp for metal core multilayer boards of 230 to 270 degrees F' (110 to 130 C'). It was scary at fir
Electronics Forum | Thu Oct 31 16:13:46 EST 2002 | babe
If your processing with Nitrogen, tombstoning can be caused by your cooling rate. Go thru the solid/liquid phase of the solder slower..iN other words as you transition into or out of the liquidus pahse if 63/37 alloy 183C, ensure that your Delta are
Electronics Forum | Mon Nov 25 20:24:13 EST 2002 | bcceng
Maxtim, Again I have implemented BGA rework in four CM's and the machine that I have selected is the Conceptronics. In contract manufacturing you will have to be prepare to rework from the smallest to the largest boards with lots of ground planes. Co
Electronics Forum | Fri Jan 31 05:18:10 EST 2003 | reg
We have a customer who is going to be using the new Snapshot process. Has anyone used this process all ready. Who did you use to make the tooling etc. Was there any problems that arose during this process. The process involves screening balls into s
Electronics Forum | Fri Feb 07 15:17:14 EST 2003 | MA/NY DDave
Hi I am pretty sure it isn't the pad that is causing the problem. To me it seems like those via holes through the pcb either to an internal plane or to the other side. I can imagine creating an interesting stencil to accomodate the vias yet you are
Electronics Forum | Mon Apr 12 10:39:48 EDT 2004 | Ron Herbert
Correct preheating of the assembly is critical. Check with your flux manufacturer regarding the recommended topside pcb temperature as it enters the first wave. It is important that this temperature be achieved without burning the flux on the bottom
Electronics Forum | Thu May 06 19:13:24 EDT 2004 | Greg York
Watch your dwell time especially if larger components. Problem is normally associated with lower temp as well as insufficient flux coverage with larger massed boards or ground planes. Try to hand spray a board to check that fluxer operation is OK. If
Electronics Forum | Wed Jun 25 12:08:53 EDT 2003 | russ
I battle this all the time, I don't believe that it is the "gold corner" that is causing the problem but something with the PCB layer makeup (copper planes, or bottom side components, etc.). It could also be the nozzle you are using has a "hot spot/
Electronics Forum | Tue Aug 05 12:05:15 EDT 2003 | mleber
Through hole question - what methods can be used to obtain upflow on multi layer pwbs with huge ground planes. We are using a water soluble flux with a max temp of 220 topside. I am pushing the limits of the flux and hitting 250 topside in an attempt
Electronics Forum | Thu Apr 08 23:08:56 EDT 2004 | Ken
Well, the precision glass is for upward looking camera's. It essentially is a "perfect part". Vapor deposition lithography on glass (for Cte stability)....basically the part pattern (or part fids) is compared to its target location (same pattern on
