Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Frank J. de Klein

#16262

Temperature profile req's for Pin In Paste process | 10 April, 1998

I would like to invite everyone to share/discuss information/knowledge/experience they have with the req's that are assumed to be valid for the temperature/time relation in the process of reflow soldering Pin In Paste, Intrusive Reflow or whatever you want to call it. The reason for posting this invitation is that papers on the subject rarely discuss the thermal req's while many people (in practice) are in doubt or unaware of what is really essential. Frank J. de Klein

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justin medernach

#16265

Re: Temperature profile req's for Pin In Paste process | 10 April, 1998

| I would like to invite everyone to share/discuss | information/knowledge/experience they have with | the req's that are assumed to be valid for the | temperature/time relation in the process of reflow | soldering Pin In Paste, Intrusive Reflow or whatever | you want to call it. | The reason for posting this invitation is that papers | on the subject rarely discuss the thermal req's while | many people (in practice) are in doubt or unaware of | what is really essential. | Frank J. de Klein Frank, What are you folks over at Dover-Soltec looking for? Most of todays ovens, at least those used by the larger contractors, have the "oomph" to adequately run a paste-in-hole process. For those of you out there who want to verify this, solder a thermocouple to a leg of your candidate for paste in hole and obtain a profile. It's a great indicator / verification tool. Best Regards, Justin Medernach Flextronics International

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Gary Simbulan

#16267

Re: Temperature profile req's for Pin In Paste process | 11 April, 1998

| | I would like to invite everyone to share/discuss | | information/knowledge/experience they have with | | the req's that are assumed to be valid for the | | temperature/time relation in the process of reflow | | soldering Pin In Paste, Intrusive Reflow or whatever | | you want to call it. | | The reason for posting this invitation is that papers | | on the subject rarely discuss the thermal req's while | | many people (in practice) are in doubt or unaware of | | what is really essential. | | Frank J. de Klein | Frank, | What are you folks over at Dover-Soltec looking for? Most of todays ovens, at least those used by the larger contractors, have the "oomph" to adequately run a paste-in-hole process. For those of you out there who want to verify this, solder a thermocouple to a leg of your candidate for paste in hole and obtain a profile. It's a great indicator / verification tool. | Best Regards, | Justin Medernach | Flextronics International

As one of the news guys on the block I am interested in paste-in-hole process, which I assume is for soldering through hole components in the reflow oven, because every time I even hint about looking into it here, the old guard gives me all the reasons that the process can't work; incomplete wetting; the solder all wets to the hole and not the pin or the other way around; it is difficult to get sufficient volume for thick boards; if you have sufficient volume it does not wick paste the heavy internal ground and power layers; it is difficult or impossible to inspect solder joints to verify sufficient paste volume; it goes on. I get the same response if I mention solder preforms. From the number of companies selling preforms and solder dispensers I have to assume that somebody is getting the process to work. So I would appreciate guidence not only concerning heat and temperature requirements but process in general. Since I run an older vapor phase oven I don't have a lot of control over profiles, My reflow temperature is my vapor temp. Thanks for the opertunity to expand vent a little frustration Gary

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Bob Willis

#16263

Re: Temperature profile req's for Pin In Paste process | 12 April, 1998

| I would like to invite everyone to share/discuss | information/knowledge/experience they have with | the req's that are assumed to be valid for the | temperature/time relation in the process of reflow | soldering Pin In Paste, Intrusive Reflow or whatever | you want to call it. | The reason for posting this invitation is that papers | on the subject rarely discuss the thermal req's while | many people (in practice) are in doubt or unaware of | what is really essential. | Frank J. de Klein As you may know I have just written a report on the use of this process with all the proceeds going to charity. The report is available from the SMART Group in the UK and should be available shortly from the SMTA in the USA. Temperature profiling of through hole parts should be conducted on the underside of the body of the component as this is often the coldest part of the board. Placing the thermocouple on the pin only on the base of the board does not always give the lowest temp. This can lead to incomplete reflow and voiding which can be seen on my video on PIHR.

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justin medernach

#16266

Re: Temperature profile req's for Pin In Paste process | 13 April, 1998

Dear Justin, I am not asking for experiences with ovens as to whether you think they are capable of THT reflow. I am asking more specifically about actual req's and experiences with THT reflow, regardless of the oven used. Your answer does not hold information which I think people are looking for at this forum. Let me give you an example of the type of discusssion/answer I think people may be looking for ; "I think that to avoid voiding and to allow the solder paste at the bottom to melt and rise up the leads, you need to have the bottom side paste/lead temperature above liquidious earlier than the top" Regards, Frank J. de Klein N.B. Feel free to email me if you want to go for a more direct discussion (fklein@asqnet.org).

************************ | Frank, | What are you folks over at Dover-Soltec looking for? Most of todays ovens, at least those used by the larger contractors, have the "oomph" to adequately run a paste-in-hole process. For those of you out there who want to verify this, solder a thermocouple to a leg of your candidate for paste in hole and obtain a profile. It's a great indicator / verification tool. | Best Regards, | Justin Medernach | Flextronics International

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Justin Medernach

#16264

Re: Temperature profile req's for Pin In Paste process | 13 April, 1998

| | | I would like to invite everyone to share/discuss | | information/knowledge/experience they have with | | the req's that are assumed to be valid for the | | temperature/time relation in the process of reflow | | soldering Pin In Paste, Intrusive Reflow or whatever | | you want to call it. | | The reason for posting this invitation is that papers | | on the subject rarely discuss the thermal req's while | | many people (in practice) are in doubt or una Bob, Thanks for the input. I had never thought about that. I try to plug the thermocouple into the hole to understand what is happening in the hole. Perhaps this evaluation requires destructive testing. Perhaps the best way to understand what is happening in the barrel is to remove a pin and substitute a thermocouple in its' place. It can be inserted from the top or bottom but at least the same thermal mass is present (assuming that the pin isn't going to perform much differently than the thermocouple wire. However, I'm sure the pin must conduct some amount of heat into the barrel so maybe this isn't valid. Your comments? Best Regards, Justin Medernach Flextronics International

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