Electronics Forum | Fri Aug 10 04:19:05 EDT 2001 | wister
There are lots of voids at solder joint of chips,the thickness of multilayer pcb is 3.2mm,top side have lots of chip component and bottom side has several BGA and QFPs.For top side profile,the preheat time is about 100s,soak time is about 75s,time ov
Electronics Forum | Thu Jun 17 09:50:27 EDT 1999 | Brian Wycoff
| | WOULD LIKE TO DO RELOW OF 2 SIDED SMT BOARDS. USUALLY THE BOTTOM SIDE HAS RESISTORS AND CAPS ONLY. WHEN THE BOTTOM OF THE BOARD HEATS UP, THE PARTS ARE FREE TO MOVE AND ONLY SURFACE TENSION WILL KEEP THE COMPONENT FROM FALLING OFF. | | CAN BOARDS
Electronics Forum | Wed Mar 31 13:05:46 EST 2004 | JoeH
Anyone used this package? It's Cygnal PN C8051F300. The part has bottom side, flat terminations (like a BGA without the balls). There is metalization on the sides of the package but it's not plated (bare copper). Metalization on the bottom is pla
Electronics Forum | Thu Jul 12 20:20:31 EDT 2007 | seankim10
I�m having problem with PCB with 16mil thickness due to warpage. the board convex up in the middle after 1st reflow. It seams the warpage is caused by CTE mismatch between PCB and multiple TSOP's, which are covering ~80% of the bottom side board area
Electronics Forum | Fri Aug 28 03:03:00 EDT 2015 | grimus
Thank you all for your advice. You are right this is two sides board, and dropped parts are on bottom side, and it is refered just to very light switches. I am using same temperature setup for top and bottom. What is interesting I am manufacturing t
Electronics Forum | Fri Dec 22 12:17:02 EST 2000 | vickij
Hi! Has anyone out there ever tried to use a high-temp and a low-temp solder paste on a double-sided board without using an adhesive? (Populate the bottom side with the high temp paste, reflow, turn it over, then run the top side). I looked in the
Electronics Forum | Thu Apr 05 09:18:14 EDT 2007 | pjc
Please note that pin holes and blow holes are not always defects. The latest IPC 610A Rev D workmanship standard has them as process indicators- depending on Class. I don't have the document handly while writing this. It would be good to look that up
Electronics Forum | Mon Jun 18 10:11:52 EDT 2007 | dyoungquist
Almost every board/panel we build is double sided and we use an MPM SPM screen printer with no problems. The screen printer is not the cause. We have seen heavier parts fall off the first side when going through the reflow for the second side. We
Electronics Forum | Tue Mar 27 01:52:23 EDT 2018 | buckcho
Hello Diego, are the components missing on the first side or the second side. Like Mr. Evtimov said, you can check before the oven the pcbs's visually and see what happens after the oven. In this way you can see if it is the oven for sure. Then there
Electronics Forum | Tue Feb 11 13:22:22 EST 2020 | rgduval
Sebas, I suspect that your finding of needing the fillet for the card to work is a false finding. One that I dealt with for many years in assembly. As a bottom terminated device, a fillet to the side terminals of the device is not required. Adequ
