Thank you all very much. This is excellent information and really helps when putting a process together. Regards, John John Fahey Manufacturing Engineer Echelon Corp 415 Oakmead Parkway Sunnyvale CA 94085 [log in to unmask] Phone: 408 938 5330 Fax: 408 328 3804 -----Original Message----- From: Phil Nutting [mailto:[log in to unmask]] Sent: Thursday, August 16, 2001 2:05 PM To: [log in to unmask] Subject: Re: [TN] ''Encapsulating/Potting PCB Assemblies" Phil, You are 100% right. We had an assembly the would fracture a Torroid with a 1/2 inch cross section as the epoxy cured. We fixed it by putting in a 1½ inch diameter "relief plug" made of rubber molding compound next to the torroid. This eliminated the stress caused by the epoxy shrinkage. Another possible item is next level of assembly. We put some potted assemblies in dielectric oil. The oil can do funny things to different materials. It causes polyolefin heat shrink to get soft and squishy. And uncured RTV, what a mess it causes as is dissolves and coats everything. Phil -----Original Message----- From: Crepeau, Phil [mailto:[log in to unmask]] Sent: Thursday, August 16, 2001 4:28 PM To: [log in to unmask] Subject: Re: [TN] ''Encapsulating/Potting PCB Assemblies" hi, you got some really terrific suggestions. if i overlooked a similar response as mine, i apologize. what you need to be aware of is the importance of selecting a potting compound that won't shrink much during cure and that won't fracture during any temperature cycling that your potted assembly may be exposed to. stresses on potted magnetic components may change their performance. phil -----Original Message----- From: John Fahey [mailto:[log in to unmask]] Sent: Thursday, August 16, 2001 7:57 AM To: [log in to unmask] Subject: [TN] ''Encapsulating/Potting PCB Assemblies" I have recently come upon a requirement to encpasulate/pot a small PCB assy containing a T/H transformer. Size is approx .5"W x .5"L x .3" H Can anyone who has experience in "Potting" or "encapsulating" technologies ,especially potting PCB assemblies, give me some hints/starting points, etc. I would be very interested in any issues to watch out for, recommended potting materials, equipment, standards to adhere to, tests, etc. Basically anything that would be helpful. Thanks in advance, John ------------------------------------------------------------------------ --------- 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 ------------------------------------------------------------------------ --------- ---------------------------------------------------------------------------- ----- 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 ---------------------------------------------------------------------------------