Electronics Forum | Fri Jan 17 04:07:12 EST 2003 | iman
A) Paste Printer : A1) identify the critical SMDs' pads. (choice should go to the BGA, CSP, MLF types...RES,CAP last in line...) A2) get a Paste measurement machine that measures readings of paste height (or better - volume) you are paste printing
Electronics Forum | Fri Jan 17 16:24:04 EST 2003 | MA/NY DDave
Hi I haven't seen the DEK software you describe in action or studied it, yet I will tell you to be careful of some of the software on the market even from good companies. Spend the time needed to understand how the software makes the calculations,
Electronics Forum | Fri Jan 10 08:52:31 EST 2003 | nifhail
We are typical SMT subcontracting house. Recently I received RFQ for brds with DCA or Flip Chip technology. In our factory we only have typical SMT machines i,e Printer-HSP chipshooter-GSM IC placer-reflow oven. What are additional machines and pro
Electronics Forum | Fri Jan 10 10:09:42 EST 2003 | mantis
Hi In selecting or substituting a capacitor for use, consideration must be given to (1) the value of capacitance desired and (2) the amount of voltage to be applied across the capacitor. If the voltage applied across the capacitor is t
Electronics Forum | Fri Jan 17 22:08:31 EST 2003 | iman
try using thermal pads under the area without the balls. yeah, its a pain but we did it before for lot run of 500pcs BGA. Not feasible for mass production run, you say? well, thats why there's a thing called DMF, and why its the designer guys res
Electronics Forum | Mon Jan 13 17:50:54 EST 2003 | jonfox
I was looking for some good documentation that could nail down some pros/cons of voids, but haven't found any. The biggest issue is if you are going to temp cycle the chips/PCB after assembly. Depending on the cycle, the situation of the test, it c
Electronics Forum | Fri Jan 24 18:37:08 EST 2003 | Kelly
I am in Supplier Quality and it seems that the quality/service has gone down with most of our current suppliers. The automotive industry lead times definitely impact the quality as well as many PWB shops downsizing in the US. The move to off-shore fo
Electronics Forum | Mon Jan 27 10:33:16 EST 2003 | MA/NY DDave
Hi Just keeping this alive to see if anyone else posts. It seems to me that this might be a degradation due to life cycles of all products/services as they progress from creating high profits to being driven down and down in price. Topped off with
Electronics Forum | Fri Jan 17 15:36:23 EST 2003 | davef
How do 0.5 mm pads on the board help paste release from the stencil? Paste release from the stencil is a function of: * Paste * Printer operation * Stencil design You have no obligation to made your stencil apertures the same size as the pads on yo
Electronics Forum | Mon Jan 20 17:42:45 EST 2003 | jonfox
Double check the data sheets for your paste. Just as an example, ou Indium paste has a recommendation for the Heating, Liquidus, and Cooling stagees of reflow. They recommend a linear ramp up of 0.5 to 1.0 degree C. In the Liquidus stage, a peak t
