Continuing with a previous posting, Amkor uses the following pad to ball size [mm] relationship: Package||PBGA||PBGA||PBGA||SuperBGA||SuperBGA||fleXBGA ||fleXBGA Pitch||1.5||1.27||1.0||1.27||1.0||1.0||0.8 Ball diameter||0.76||0.76||0.50||0.76||0.63||0.45||0.45 Pad size||0.63||0.63||0.45||0.63||0.55||0.45||0.30 IPC-7095 suggests the ball size reduction approach that a couple of others mentioned Nominal Ball Size ||Reduction||Nominal Land Dia||Variation 0.75mm ||25% ||0.55mm ||0.60-0.50mm 0.60mm ||25% ||0.45mm ||0.50-0.40mm 0.50mm ||20% ||0.40mm ||0.45-0.35mm Dave Fish ----- Original Message ----- From: "Genny Gibbard" <[log in to unmask]> To: <[log in to unmask]> Sent: Tuesday, November 06, 2001 7:24 AM Subject: [TN] BGA's in design > OK, in the next few months we will probably design our first board that uses > a BGA, and we are jumping in with both feet. This board will have a 304 > ball 1.27mm pitch, a 432 ball 1.27mm pitch, a 196 ball 1.00mm pitch and a > 256 ball 1.00mm pitch. > Are there any resources for free land patterns for these babies? Or how do > you determine the pad size knowing the ball diameter and pitch? Almost > every place I found on the web with BGA patterns was selling them. I was > looking at the table of contents for the SM-782A standard and it only > mentioned 1.27pitch. Is the information in the standard easily scalable to > smaller pitch? It could be a hard sell to convince my company to buy > patterns, which means we will probably make our own which doesn't always > make for very good DFM. > Secondly, (I hesitate to ask this, because I may get a bunch of > solicitations, but) does anyone have some recommendations for board > fabricators in Canada that can handle the BGA requirements? We have had > questionable quality from most or all of our current board vendors at some > time or another (remember the switched inner layers?) and I am looking for > some new sources. > > Regards. > > Genny Gibbard (mailto:[log in to unmask]) > > -------------------------------------------------------------------------- ------- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL > Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 > -------------------------------------------------------------------------- ------- > --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------