Electronics Forum | Thu Jul 15 21:18:27 EDT 1999 | Scott McKee
| I'm designing a board where the parts will only fit if I do one of the following: | | 1. Put BGAs on both sides | | 2. Put BGAs on top, smt TSOPs directly underneath and using blind vias to keep the real estate on the bottom side below the BGA pa
Electronics Forum | Thu Jul 15 12:35:19 EDT 1999 | Earl Moon
| I use a Transition Automation Semi- Automatic stencil printer with laser cut frameless stencils. My solder paste is an SN63/PB37 RMA 291. I do not operate with in a controlled humidity enviroment. The room temp generally runs around 70 deg's but hu
Electronics Forum | Mon Jul 12 09:13:08 EDT 1999 | Mark Charlton
I need some advice concerning reflow of a BGA-292. Since I am not ready to change my entire process to no-clean, I decided to place the lone BGA-292 on a proto run using our BGA re-work station. The pcb is a moderately dense, single-sided, 8-layer
Electronics Forum | Fri Jul 09 19:35:05 EDT 1999 | Earl Moon
| Hi Carol- | What you are asking for can be done. Variables you must account for include the paste viscosity, dispensing head speed, dispenser height relative to board surface, and needle size. You can use most any semi-automated system such as Ca
Electronics Forum | Sat Jul 10 02:47:27 EDT 1999 | Scott
| | | Hi! | | | I'm a process engineer attempting to do a capability study on our existing convection reflow oven - Heller 1500. It was recommended by an independent consultant to do at the very least, load testing, process ready testing, and board
Electronics Forum | Tue Jul 06 12:46:27 EDT 1999 | John Thorup
| | We are looking for some subcontractors to do surface mount | | technology boards for us. Is there anything I should pay specific | | attention when I visit the subcontractor's site? | | Thank you for any advice | | | Wolfgang has a good poi
Electronics Forum | Sat Jul 10 00:57:17 EDT 1999 | Scott
| who can tell me how viscosity measurements are really effective in smt process control? what can I monitor? Is it depending from fine pitch size? | Thanks a lot. | g. d'andrea | The last place I worked used a viscosity meter, funny how little was
Electronics Forum | Mon Jul 05 18:45:01 EDT 1999 | JohnW
| Is the no clean solder paste as good? We are wondering if we can elliminate the wash when we change from through hole to surface mount. | John, No clean is as good as your process, and the paste you are using. Everything I do is no clean and I h
Electronics Forum | Wed Jun 30 17:58:01 EDT 1999 | Boca
| My guess would be trapped flux continuing to be active after soldering. Is the tarnish there immediately after exiting the machine? Do you remove the mask and wash right away? If the solder is reflowing under the mask on the component side it wo
Electronics Forum | Fri Jun 25 03:16:38 EDT 1999 | Scott Davies
Wayne, Earl, I wish there was some way we could toss our wave solder machine forever! Unfortunately, we haven't found a way yet to do paste-in-hole reflow for large numbers of thru-hole axial and radial components, which we insert on Universal machi
