Electronics Forum | Sun Mar 05 13:02:00 EST 2000 | dave
We used this type of paste in a fine pitch application for over two years with no problems. You must be very careful of any (dust)or spillage while mixing for obvious reasons. In my opion the very thing that makes it interesting "freshness" is also i
Electronics Forum | Thu Mar 02 15:12:50 EST 2000 | Robert Hartmann
To restate my question of earlier, if I have a .020" sphere before reflow, and my pad opening in the dielectric is .017", is there a rule of thumb to calculate the height of the sphere after reflow? We are using 62Sn/36Pb/2Ag spheres. This should h
Electronics Forum | Thu Mar 02 14:33:26 EST 2000 | Doug Philbrick
I have a customer wanting to hide the identity of a particular component on a PCB assembly. The product cannot be potted and since the PCB is the product he doesn't want to pour over that one chip for aesthetics reasons. Any ideas on ways to permanen
Electronics Forum | Thu Mar 02 09:13:07 EST 2000 | jacqueline Coia
Could anyone please tell me if there is a quick simple formula for working out the ideal SMD footprint for a 52 pin QFP using the dimensions specified on the manunfacturers component drawing. I know of the IPC 'SMD land patterns' standard, which I e
Electronics Forum | Thu Mar 02 11:57:25 EST 2000 | Wolfgang Busko
Did you try the online-calculator at the IPC-page. If you have the datasheet it should be no problem. For wave soldering I can�t tell if it�s suitable for that particular part, but you should add extra pads at the end of each column to solderbridging
Electronics Forum | Thu Mar 02 04:23:49 EST 2000 | Alan
Hi, I'm trying to put together a directory of component manufacturers that offer a lead free alternative for their devices. If anyone knows of manufacturers that are producing these devices then it would be greatly appreciated if you could pass the
Electronics Forum | Tue Feb 29 21:18:00 EST 2000 | Gwen Z
When an assemblied board was on active service, what's the main reason for its failure:the package broken; the mechanics fatigue failure under thermal cycle; the corrosion caused by salt and vapor; the broken chip inside the package etc. I think all
Electronics Forum | Tue Feb 29 19:30:09 EST 2000 | Hon Choi
Good Day, Can anyone tell me if component dimensions are standardized from vendor to vendor? For example, would an sot89 component from one vendor have the same dimensions, lead pitch and length as that from another vendor? And is there any place
Electronics Forum | Thu Mar 02 07:38:58 EST 2000 | Roni Haviv
Hello, I had experienced this kind of problem; Because the Au film is very thin (flash gold..) it is sometimes porositive and the Ni barrier below get Oxidation. After reflow there seems to be good solder fillets (visualy perfect!) but the leads wit
Electronics Forum | Thu Mar 02 15:20:13 EST 2000 | Glenn Robertson
Dave - You certainly have a good point regarding the multiple part numbers and board suppliers, but a rework process for black pad has been reported. See the SMTAI 1999 Proceedings article by Zequn Mei (page 407). It involves flux and solder wi
