Greetings all, this is my first submission.  I have read all of the
archived information from the past few years on intrusive reflow. 
Hopefully in the future I will be providing more, and needing less.  

I am currently a graduate research assistant examining various 
forms of reflow soldering (Heller 1800 convection & Universal 4815 IR)
odd form and high temp capable through-hole components.  I have a very
sound understanding of the basic process and its limitations.  I am
interested in determining the degree of research that has been done in
the following areas, so my research efforts will be most beneficial to
all.  

1] In cases where connectors may be 3 rows or more, the inner rows 
are often constrained in stencil printing (insufficient volume)
- Is there documented experimentation to measure the strength / 
reliability of pin in paste joints of various sizes versus typical 
wave soldered joints?  

2] The volume models for solder paste volume calculation proposed suffer
from the lack of exact "amount that fills the PTH" upon stencil
printing. I have read a few papers on the topic of hole fill (Bill
Barthel, EAC among others)  Is there a scientific understanding to how
the solder paste fills the PTHs and what significant variables are
responsible?

3] How often, if ever, are solder preforms used for this process?  What
types work best (prefluxed?, flux before)?  I saw one company that
provides preforms preattached to components.  Does anyone have
experience with this?  Does the component seat properly upon reflow?

4] One active area of my research is automatic solder paste dispensing
both prior to and after component placement for this process.  There
doesn't seem to be much reseach on this topic, even from the dispensing
camp, am I correct?  Does anyone have information or advice?

5] Are there companies actively using double stencil printing processes,
either with a relieved second stencil or printing on 2 sides.  What are
the limits to a step stencil technology?

As a graduate researcher, I am very interested in setting up industrial
/ research contacts of people working on this pin in paste / intrusive
reflow process.  Please contact me with information or ideas of research
.  I am currently developing a process sequence, and if I don't have to
start from the basement, that would be great.   

Thank you all for your consideration, and I hope to hear back soon.
Jay B. Hinerman
Graduate Research Assistant
State University of New York at Binghamton
[log in to unmask]
607 779 4901 (lab)
607 779 5239 (desk)
607 779 4646 (fax)

***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To subscribe/unsubscribe send a message <to: [log in to unmask]>   *
* with <subject: subscribe/unsubscribe> and no text in the body.          *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact   *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
***************************************************************************