And I would like to point out yet again that most of these materials are fully fluorinated materials that have incredibly long atmospheric lives and thus have terribly high global warming potentials. I would recommend using food grade carbon dioxide instead. You can buy a "gun" to put on the compressed gas tank to aim the liquid/gas at the component in question. Sorry I can't remember the name of the company right now, but if you check the archives under my name for the '96 to '98 time frame you might find it. And others might chime in to augment my failing memory. ;( regards, Bev Christian Research in Motion. -----Original Message----- From: Carl VanWormer [mailto:[log in to unmask]] Sent: April 24, 2002 10:23 AM To: [log in to unmask] Subject: Re: [TN] Freeze Spray Trouble Shooting As to the cause of your problems, I vote for timing problems, with a close second guess at system noise caused by impedance mismatch on long control signal lines. I'm Carl and I'm a Freeze Spray user . . . Now that I've got that off my chest, I'd like to say that I seldom wreck stuff, and can usually find thermal mechanical intermittents and (particularly) timing problems. Frozen parts seem to have faster transition edges. A long time ago, I was able to make our 4 MHz Z-80 processor system work at 7.8 MHz by freezing the processor, EPROM, and RAM chips (with a variable oscillator for testing). Recently, I've found that I could fix (or cause to fail) a new design by squirting the Altera (EPLD) or processor. The culprit was "timing" and a poorly designed (overloaded) set of control and bus lines. The difference in timing between the Altera latching in the correct and incorrect data was seen to be about 1/2 nano-second. By selective heating (and/or cooling) of the various chips, I could "adjust" the timing to make the device work or fail. Of course, we had to fix the timing problem, but my first line of discovery is (often) Freeze Spray. When I've run out of the stuff, I grab the "Dust-Off" can and run it in "inverted" mode to get the Freeze Spray effect. p.s. After reading items in this forum about BGAs and circuit cooler, I've vowed to never squirt the BGA packages. There is waaaaaaay too much chance of wrecking something there, since there are no leads to absorb the flex caused by differential thermal expansions. Carl Van Wormer Cipher Systems 1815 NW 169th Place, Suite 5010 Beaverton, OR 97006 Phone (503)-617-7447 Fax (503)-617-6550 -----Original Message----- From: Ken Carlile [mailto:[log in to unmask]] Sent: Tuesday, April 23, 2002 9:12 PM To: [log in to unmask] Subject: [TN] Freeze Spray Trouble Shooting We recently received a prototype batch of 4 boards and experienced 4 for 4 failing test. Our techs sprayed down certain chips with Freeze Spray and the board began working properly, at least for a short period of time. I have checked prior tech net postings and have found fantastic responses as to why Freeze Spray can damage a the IC or board, but can anyone explain why they would begin functioning properly. Being a rookie component engineer I can fully understand the issues related to freeze spray, but out techs and design engineers are just going to point the finger since their units work when sprayed. To further complicate the matter the chips that are being sprayed are not all the same manufacturer and I can easily rule out a component failure. Our senior engineer thinks that it may be timing related since the main circuit being froze is the Altera PLD (20K400E) and related circuitry. Can anyone defend the use of Freeze Spray? Can anyone present a logical failure mechanism? /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ The best Freeze Spray argument to date was Werner Engelmaier's: http://jefry.ipc.org/scripts/wa.exe?A2=ind9907&L=TechNet&D=0&m=23823&P=55370 However this points to failure after spray not the opposite. ---------------------------------------------------------------------------- ----- 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 e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/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 e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/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 e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/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 ---------------------------------------------------------------------------------