Doug, I consider an under-fill as an adhesive, and elasto-plastic to be an adjective describing the underfill's properties. ....What would an under-fill be without the ability to adhere to the surfaces involved?? In very quick consideration, I classify an under-fill as: a material [vs process], a polymer [vs metallic/non-organic], an adhesive [vs a non-adhesive] As far as the cured properties of the underfill go, I consider them to properties common to: a thermoset, thermoplastic, hybrid thermoset/thermoplastic [and would consider elasto-plastic to be fourth variant possibly most descriptive of products with a dominant silicone backbone, ... with more property descriptors sure to follow]. Some simple thoughts for a Friday morning. Steve -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Douglas Pauls Sent: Friday, June 05, 2009 8:24 AM To: [log in to unmask] Subject: Re: [TN] Coating, Encapsulation, and Potting I would agree. It seems that there is a concensus that "encapsulation" is the high level term, with the others being sub terms or lower level, as Ben suggests. I will see if I can distill the inputs a little, let the subconcious work on them over the weekend and next week come up with the next round of questions. For now, let me ask this: would you consider an underfill material as a material in the "adhesive" class? I was having a conversation this week with Barry Ritchie of Dow Corning and he used an interesting term - elastoplastic. It would seem to me that an underfill would be an elastoplastic material. Doug Pauls Rockwell Collins "Gumpert, Ben" <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 06/05/2009 07:02 AM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to "Gumpert, Ben" <[log in to unmask]> To [log in to unmask] cc Subject Re: [TN] Coating, Encapsulation, and Potting I don't have a suggestion for definitions, just one of organization: I see all of these terms (potting, coating, underfill) as being sub-classes to the overall group of encapsulants, with the term encapsulant being used when the others do not apply. Ben -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Joe Fjelstad Sent: Thursday, June 04, 2009 3:04 PM To: [log in to unmask] Subject: Re: [TN] Coating, Encapsulation, and Potting Interesting question Doug 1) My mental image is that it is that the term is related to processing and potting is most often done atmospherically, with occasional vacuum assist and encapsulation under pressure but it is pretty fungible with lots of fuzziness between the two. A potted assembly is definitely encapsulated when finished. 2) Likely? Yes but don't know where 3) Thickness of the coating seems reasonable but don't know where to draw the line. 250 micron? 100? 500? Perhaps a percentage of total thickness? 5%? 10%? 4) In neither (or both depending on process). The other two generally provide complete coverage of the device or assembly underfill is by definition partial. Joe In a message dated 6/4/2009 11:33:27 A.M. Pacific Daylight Time, [log in to unmask] writes: Good afternoon all, All this talk of underfill sparked a reminder of an IPC action item of mine. Unknownst to most of you , I signed you all up on some of my committees. There will be a new task group addressing potting and encapsulation, which will meet at the Fall IPC. We already have conformal coat task groups. So, I wish to initiate a series of questions and illuminating debate. Pardon me if I fall short on the illumination part (leave it alone Dewey). 1. What would you consider to be a definition of "potting" and a definition of "encapsulation"? 2. Are there standard definitions for these somewhere? They don't exist in IPC as far as I know. 3. What would you consider to be the boundary between conformal coating and "potting or encapsulation"? I have my own opinions but want to hear yours. 4. In what class would you consider an underfill to be in? That's enough homework for now. Doug Pauls Rockwell Collins --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- **************Limited Time Offers: Save big on popular laptops at Dell (http://pr.atwola.com/promoclk/100126575x1221354145x1201369495/aol?redir =http:%2F %2Fad.doubleclick.net%2Fclk%3B215221161%3B37268813%3By) --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------