When conducting Dye and Pry on our hand on FA workshops at ITRI I normally use a special tool or a "Wood Chisel" which is the same width as the package or wider. The part can be easily lifted without any damage to the areas you are trying to inspect. It makes for a simple practical demonstration. The wood chisel or tool has an angled blade to allow a lifting force with pressure across the width of the device. See gif file online at www.bobwillis.co.uk/images/bobwillisD&P.gif When I get some time I make a video clip of the complete process for the IPC web site. Like any process some practice allows you to develop the technique. Kim keeps asking for defect analysis for blog content. If anyone wants a procedure for this send me a email off line. I will produce when I get my Productronica exhibition project out of the way The force required is higher on standard laminates, better pad adhesion, weaker on most high Tg laminates for the reasons everyone knows. The correct procedure is to have a indication from your customer or test department where the fault is located. Which edge is close to the defect area, you then lift from the opposite side of the device. Using a wood chisel allows you to leaver off the device, with care you don't even damage the row of balls next to the chisel point. Trust me it works fine! Trying to lift parts from different corners or with thin blades generally damage the package or point you are trying to examine. When doing D&P always wear gloves otherwise your fingers will be red or yellow for a few days!!!!! Have a great weekend guys Bob Willis 2 Fourth Ave, Chelmsford, Essex, CM1 4HA England Tel: (44) 1245 351502 Fax: (44) 1245 496123 Mobile: 07860 775858 www.ASKbobwillis.com www.SolderingStandards.com New Package on Package Workshops 24th November www.ASKbobwillis.com/PoPWorkshops.pdf PCB Inspection & Quality Control Workshop 3rd November www.ASKbobwillis.com/faworkshops.pdf Book Bob's "Step by Step Failure Analysis Workshop"4th November www.ASKbobwillis.com/faworkshops.pdf Package on Package Assembly & Inspection Workshops 21th January ITRI www.ASKbobwillis.com/PoPWorkshops.pdf -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Victor Hernandez Sent: 22 October 2009 12:00 To: [log in to unmask] Subject: Re: [TN] [spam] RE: [TN] ENIG Issue Is anyone conducting pull test using an adhesive/epoxy for D&P. It has worked well for me for any size BGA, even CPU sockets. Victor, -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier Sent: Thursday, October 22, 2009 5:47 AM To: [log in to unmask] Subject: Re: [TN] [spam] RE: [TN] ENIG Issue Hi Inge, Yes, I have done 'Dye & Pry.' The 'prying' part is not easy for large components. I did it starting at the corners working piecemeal around the 4 sides. LN2 is a god idea—I do not see how it would cause misleading results, please explain. Werner -----Original Message----- From: Hernefjord Ingemar <[log in to unmask]> To: [log in to unmask] Sent: Thu, Oct 22, 2009 4:44 am Subject: [TN] [spam] RE: [TN] ENIG Issue By the way, speaking SJ issues, has anyone of you experience from Die & Pray technology, like the one described by some guys, who tested large game boards, see figur 9 and 10, dye and pry testing? It's not easy to pry so large BGAs. What kind of tools etc do you use? Myself, I had to dip the board under test in LN2 before prying off the superBGA. That's not good, the low temperature can mislead the result. /Inge http://www.celestica.com/uploadedFiles/Home/PBfree_process_paper.pdf -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier Sent: onsdag 21 oktober 2009 15:51 To: [log in to unmask] Subject: Re: [TN] ENIG Issue Hi Vladimir, Maybe we should simply drop the name 'Black Pad' entirely-too much baggage and confusion. Maybe we should refer to them by their failure modes and damage mechanisms-solderability issues due to 'galvanic corrosion', brittle fracture due to P-enrichment, brittle fracture due to 'any other cause applicable. Werner -----Original Message----- From: [log in to unmask] To: Werner Engelmaier <[log in to unmask]>; [log in to unmask] Sent: Wed, Oct 21, 2009 7:39 am Subject: Re: [TN] ENIG Issue Werner, Yes, I agree that there are two different phenomena BP and BF, but I can not agree on the statement that the root cause for BF(brittle fracture) is high P content. Regards, Vladimir SENTEC 11 Canadian Road, Unit 7. Scarborough, ON M1R 5G1 Tel: (416) 899-1882 Fax: (905) 882-8812 www.sentec.ca From: Werner Engelmaier <[log in to unmask]> Date: Tue, 20 Oct 2009 23:59:34 -0400 To: <[log in to unmask]>; <[log in to unmask]> Subject: Re: [TN] ENIG Issue Vladimir, Indeed you sent me that ATOTECH paper, but I have several references that disagree with their definition, as well as others that agree with the Atotech paper. There seem to be (at least) 2 different 'defects' at work-one with hyper-galvanic corrosion of the Ni during Au-plating causing soldering problems, and another causing brittle separation due to a weakened interface cause by too much P. Are we in agreement on this? I do not really care what you call either of them-clearly the root cause is different in these cases and so is what needs to be done. Clearly, what we need is for the IPC to form a committee to provide proper definitions and 'names.' Werner -----Original Message----- From: [log in to unmask] To: TechNet E-Mail Forum <[log in to unmask]>; Werner Engelmaier <[log in to unmask]> Sent: Tue, Oct 20, 2009 11:23 pm Subject: Re: [TN] ENIG Issue Werner, We've been through it several times already. As far as I know, BP was defined as a case of poor Ni-P plating with cavitation present in the layer. I think I sent you an old ATOTECH paper on the topic a while ago. Regards, Vladimir SENTEC 11 Canadian Road, Unit 7. Scarborough, ON M1R 5G1 Tel: (416) 899-1882 Fax: (905) 882-8812 www.sentec.ca -----Original Message----- From: Werner Engelmaier <[log in to unmask]> Date: Tue, 20 Oct 2009 22:57:21 To: <[log in to unmask]> Subject: Re: [TN] ENIG Issue Hi Vladimir, Then we are not communicating. Please explain to me what YOU mean by 'BP failure'. When I say 'BP failure', I mean it is because too much P between the Ni and the IMC layers has weakened the bond leading to brittle separation on sufficient loading. I do not differentiate as to the cause(s) for too much P. For me they describe a damage mechanism. You can similar appearance with too much and too little P. Werner -----Original Message----- From: [log in to unmask] To: Werner Engelmaier <[log in to unmask]>; [log in to unmask] Sent: Tue, Oct 20, 2009 10:44 pm Subject: Re: [TN] ENIG Issue Werner, You just confirmed what I said in my previous e-mail. You customer got failure with black appeared pads, but it wasn't BP failure. Similar appearance doesn't mean the same mechanism. Regards, Vladimir SENTEC 11 Canadian Road, Unit 7. Scarborough, ON M1R 5G1 Tel: (416) 899-1882 Fax: (905) 882-8812 www.sentec.ca From: Werner Engelmaier <[log in to unmask]> Date: Tue, 20 Oct 2009 22:16:40 -0400 To: <[log in to unmask]>; <[log in to unmask]> Subject: Re: [TN] ENIG Issue Hi Vladimir, I have one client who experienced 'Black Pad' after 9(!) soldering operations. The P-content got progressively worse; it peaked with the EDS spikes for P being as high as those for Sn. Werner -----Original Message----- From: [log in to unmask] To: TechNet E-Mail Forum <[log in to unmask]>; Werner Engelmaier <[log in to unmask]> Sent: Tue, Oct 20, 2009 10:07 pm Subject: Re: [TN] ENIG Issue Werner, With all due respect, I don't think you are right. Regards, Vladimir SENTEC 11 Canadian Road, Unit 7. Scarborough, ON M1R 5G1 Tel: (416) 899-1882 Fax: (905) 882-8812 www.sentec.ca -----Original Message----- From: Werner Engelmaier <[log in to unmask]> Date: Tue, 20 Oct 2009 22:01:35 To: <[log in to unmask]> Subject: Re: [TN] ENIG Issue Hi George, \While what you say in the first paragraph is correct, the second paragraph is not. 'Black Pad' is not an all-or-nothing proposition. The seeds are sown at the Ni-plating (not the Au-plating) with the P-codeposition. However, multiple or lengthy expositions to high soldering temperatures result in more Ni being dissolved to form IMCs leaving ever more P behind. This can create 'Black Pad' where none existed before. Werner -----Original Message----- From: George Milad <[log in to unmask]> To: [log in to unmask] Sent: Tue, Oct 20, 2009 9:52 pm Subject: Re: [TN] ENIG Issue As always as soon as there is a solderability issue with ENIG, "Black pad" comes up. This is a problem because it does not allow for further investigation. Everyone accepts since this is ENIG then it must be black pad. If this was a black pad issue the back side should have exhibited the same problem. BP occurs during the plating of the gold on top of the Ni. BP cannot differentiate one side from the other. Do not accept BP as the answer and keep investigating. Regards George Milad George Milad National Accounts Manager for Technology Uyemura International Corp (UIC) 249 Town Line Rd Southington CT 06489 [log in to unmask] Cell: (516) 901 3874 --------------------------------------------------- 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 ----------------------------------------------------- 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