This is NOT a firm answer, but just a guess. Perhaps your TSOP 10x20 - 40 pin is a TSOP Type II. The TSOPs in IPC-SM-782 are TSOP Type I. JEDEC has added a new TSOP outline called TSOP Type II. The IPC -SM-782 committee is looking at the outlines to develop new land patterns for the Type II, but is currently focusing their efforts on publishing land patterns for BGAs. When that is completed, we will finish the Type II land patterns. Lisa Williams IPC 2215 Sanders Road Northbrook, IL 60062 URL: www.ipc.org >>> Walter Williams <[log in to unmask]> 06/01/98 02:44PM >>> Greetings all I have and Intel 28F008S5 flash I trying to create a land pattern for. The data sheet does not give any part dimentiond but claims it to be a TSOP 10x20. The 782 IPC book says that the pin spacing .3 mm. But this has proven to be incorrect. Does any one have any insight as to why the part mfg. and the IPC book differ? There is some information that I left off. The Intel data sheet also says it is a 40 pin package. A little over sight on my part. TSOP 10x20 40 pin ************************************************* Thanks Walter L. Williams, Circuit Board Designer I-O Corporation, SLC, Utah Industry leader in IBM AS400 connectivity products [log in to unmask] Voice: 1-801-972-3558 ex 123 Alternate: 1-801-973-6767 ************************************************* Carpe Diem ################################################################ DesignerCouncil E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE DesignerCouncil <your full name> To unsubscribe: SIGNOFF DesignerCouncil ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ DesignerCouncil E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE DesignerCouncil <your full name> To unsubscribe: SIGNOFF DesignerCouncil ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################