Electronics Forum | Fri May 31 16:36:57 EDT 2002 | davef
If you know about 'BIG DADDY', you know what I know. A nearby thread [ http://www.smtnet.com/Forums/index.cfm?fuseaction=view_thread&CFApp=2&Thread_ID=1678&mc=2&forum_idx=40 ] addressed your question more directly, but certainly didn't drill-down t
Electronics Forum | Thu Jun 06 15:55:28 EDT 2002 | arzu
I agree with the others and experienced the problem myself this week. Solderballs at the side of the chips. I looked at the board and found that the chip is pressing the paste away too much. This in combination with our quite big pads(and stencilaper
Electronics Forum | Tue Jun 04 17:05:52 EDT 2002 | davef
Solder balls floating around on the air currents of a reflow oven. I sincerely doubt it. Could the solder on your gold fingers be from: * Excess placement force during P&P? * Ejactula from solder deposits during rapid preheat ramp rates? * Ejactula
Electronics Forum | Wed Jun 05 12:22:45 EDT 2002 | Bob
No. Placement force is fine. Also boards have been inspected prior to reflow using microscope with no evidance of misplaced solder balls. The ramp rate has been reduced to acceptable limits, typically .8 - 1.5 degrees per sec. Outgassing from eithe
Electronics Forum | Wed Jun 19 15:13:56 EDT 2002 | dougt
I worked for a place that built flight boxes for the military and some comercial. As Russ stated, wrist straps were used where they could be used. In areas where they were in the way, i.e. room where they masked and sprayed the boards, they had the
Electronics Forum | Thu Jun 13 11:30:41 EDT 2002 | davef
Most SMT lines are comprised of several pieces of equipment. Each piece of equipment, the components, the plant environment, and the people running the line can have / cause variations in their operation that each can affect product quality. Consid
Electronics Forum | Wed Jun 26 15:34:09 EDT 2002 | Daan Terstegge
It does work, but you must keep in mind that not only the stencil must be designed for it, but also the board. Trying to use the pin-in-paste process for a connector with an ordinary wave-solder layout will result in lots of touch-up. You'll need sma
Electronics Forum | Wed Jun 26 21:05:15 EDT 2002 | ianchan
Hi Dave F, customer calls it "warp", we can call it "twist/bow"..etc. the "warp" occurs on individual PCB cells of 28per each panel. the overall dimension of the panel is 139mm x 168mm, and each individual PCB cell is 2.4mm x 1.2mm. Thickness is 0.
Electronics Forum | Fri Jun 28 03:04:21 EDT 2002 | Dreamsniper
Forgot to include the following: Dwell time is from 55 secs to 68 secs. Indium specs for the paste is maximum peak @ 228'C and 30 to 90 secs dwell time above 183'C. PCB is a 6 layer board with Dimension of 205 x 166 mm but is slightly dense with 11
Electronics Forum | Tue Oct 01 08:01:23 EDT 2002 | mjz289
WE USE A HELLER 1500 EXL OVEN (5 ZONE OVEN) AND HAVE BEEN DOING PBGAs FROM 292 TO 780 BALLS WITH .O32" PITCH (.8 mm) AND METAL STIFFENERS ON TOP WITH NO PROBLEMS. I AM GETTING 210 - 215 DEGREES C AT THE BGA BALLS WITH 50 - 65 SECONDS ABOVE LIQUIDUS