Electronics Forum | Mon Sep 19 09:16:24 EDT 2016 | markhoch
Hi Shriram, Are you saying that there is a trace running between the pads for this 0603 capacitor? If so, this design may be causing a gasketing issue between the stencil and the PCB. The uneven height prevents the stencil from sitting flat on the PC
Electronics Forum | Mon Sep 19 21:35:54 EDT 2016 | shriram
Appreciate your suggestion. NSMD pads are used for this design, the anomalies we found are 1. the trace running between pads has a lesser solder mask height compared the other area of the pads. 2. the NSMD pads doesnot have a trench close to pad e
Electronics Forum | Wed Aug 04 16:09:48 EDT 2004 | Dreamsniper
Hi, Thanks for your reply. I run 2 boards, using the same paste, thermal profile and the same method of aqueous cleaning, 1st is a Topline test board with topline BGA (BGA 272 with 1.27 Pitch) and the 2nd is our product PCB with our BGA from Motoro
Electronics Forum | Tue Aug 03 16:52:41 EDT 2004 | Dreamsniper
Hi, What contributes to the above? I've got some BGA solder joints with a crystal like flux attached to it like a mini solder ball but do not have a perfect round shape. I had my aqueous cleaner's DI water sent for analysis and everything looks okay
Electronics Forum | Mon Aug 09 17:02:32 EDT 2004 | arminski
Hi Shean, Thanks for the analysis. "Your product looks like it may have non-solder-mask-defined pads." Yes. It is a NSMD PCB. "Does there appear to be any residues on the bare boards, and/or, BGA components prior to applying the solder paste?"
Electronics Forum | Fri Aug 06 15:32:03 EDT 2004 | Shean Dalton
Thanks for providing the pictures. We evaluated what we could see and have the following idea's. 1) Because of different thermal charatoristics between the topline and your product, your Motorola BGA solder joints may have experienced a higher refl
Electronics Forum | Thu Sep 11 15:23:31 EDT 2003 | Peter L.
I have come across a rash of failed assemblies that have 0805 capacitors and resistors, bottom side glued, wave soldered and washed. Trouble shooter reported touching up the solder joints on a few areas and the boards would pass test. I had a look a
Electronics Forum | Fri May 07 17:02:01 EDT 1999 | Earl Moon
| On 1.27mm (0.050 inches) Standard Ball Grid Array's. | The ball size diameter starts at approximately 0.025 inches. | | If the ball size decreases to 0.012 inches (due to the solder flowing down a via) is the solder connection reliable? | | This
Electronics Forum | Thu May 13 18:36:55 EDT 1999 | Andrew Wulff
| | On 1.27mm (0.050 inches) Standard Ball Grid Array's. | | The ball size diameter starts at approximately 0.025 inches. | | | | If the ball size decreases to 0.012 inches (due to the solder flowing down a via) is the solder connection reliable? |
Electronics Forum | Wed Feb 18 12:42:43 EST 2004 | babe
OK, if the sphere of the ball and the paste on the pad are both eutectic, 63/37 then the paste will reflow first causing a drop of the component, after which the spheres will reflow causing a double drop and a good intermettalic. You can see this by
