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Check the box next to each paper you want to download. You may download as many papers as you wish. After selecting papers and completing the contact information form on this page, the paper(s) will be e-mailed to you at the e-mail address you provide.

Papers about solder paste evaluation

• Leaded and Lead-Free Solder Paste Evaluation Screening Procedure

  by Aniket A. Bhave, Daryl Santos PhD, Dr. Ronald C. Lasky

  Numerous studies have shown that greater than 60% of end of line defects in SMT assembly can be traced to solder paste and the printing process. Reflowing adds another 15% or so. In light of this fact, it is surprising that no simplified procedure for solder paste evaluation has been documented. This paper is about such a procedure.

  pb-free, lead-free, stencil printing, solder paste, solder paste evaluation

  [Permanent Link to this Paper]

  Posted on 31 Mar 2010

• Six Sigma® Techniques for Solder Paste Selection

  by Wang Ming, Aniket A. Bhave, Dr. Daryl Santos, Dr. Ronald C. Lasky, Sniket A. Bhave

  Numerous studies have shown that greater than 60% of end of line defects in SMT assembly can be traced to solder paste and the printing process. Reflowing adds another 15% or so. In light of this fact, it is surprising that no simplified procedure for solder paste evaluation has been documented. This paper is about such a procedure. By using designed experiments and the measurement of critical solder paste related process metrics, we were able to develop a solder paste evaluation procedure that maximizes information about the solder paste and its processability while minimizing experimentation. While using only 12 stencil printed PWBs, we were able to generate statistically significant results that enabled us to rank solder pastes according to their performance. Response metrics that were investigated were print volume and definition before and after pause, squeegee hang up, slump, tack, release from aperture, and solder joint quality. In addition, we found such variation in solder paste volume repeatability that this criterion alone can be used as a screening procedure.

  lead-free, pb-free, solder paste evaluation, solder paste, stencil printing

  [Permanent Link to this Paper]

  Posted on 9 Mar 2010

• The Question of Sample Size: Print Performance Trials for Solder Paste Evaluation

  by Chris Anglin

  Design development of miniaturized electronics for mobile phones and other portable devices continues to challenge the required assembly capability of smaller and smaller components. Some of the components that must soon be assembled to enable these portable electronic devices include 01005 passives and 0.3mm CSPs. In addition, it is widely accepted that about 65% of all end of the line defects occur in the stencil printing process. Given all of the above, it is critical that precision stencil printing processes be further developed to support miniaturized electronic assembly.

  This paper is a summary of a sample size consideration used to collect experimental data and the process optimization techniques that are employed to establish a precision SMT printing process. Our results indicate that the industry standard stencil aperture area ratio requirement of >0.66 remains an excellent rule of thumb. However, by optimizing printer setup with custom-board recessed vacuum support, foil-less clamps, squeegee edge guards, etc., and assuring squeegee and stencil quality, we have been able to obtain acceptable stencil printing results with area ratios nearing 0.5 with Type IV solder pastes. The sample size decision tools that are employed to characterize paste performance results will be discussed in detail in the paper.

  solder paste, solder paste evaluation, area ratio, stencil printing

  [Permanent Link to this Paper]

  Posted on 25 Jan 2011

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