circuitnet
Sponsor
SEHO Systems GmbH
SEHO makes production lines smarter
Improve your work flow and reduce manufacturing costs with creative ideas and innovative solutions for automation, board handling and material management.
SEHO Systems GmbH
SMT Wastewater Treatment
Sponsor
Indium Corporation
High-Reliability for Low-Temp Processes
Durafuse® LT low-temp, high-rel solder paste is bismuth-free, reduces warpage in large BGAs, enhances thermal cycling, drop shock reliability and reduces energy use up to 15%.
Indium Corporation
Ask the Experts
QUESTIONS
  
SUBMIT
  
MEMBERS
  
JOIN
April 30, 2007 - Updated
July 4, 2007 - Originally Posted

Through-hole ratios for PCB's

In Through Hole technology, what is the best lead to hole ratio to be maintained? Is the lead to hole ratio the same for any kind of PCB finishes or does it vary? What should be the pad size on the primary side and secondary side?
M.K.
Expert Panel Responses
We ran some recent tests and reported at APEX 06 "Lead Free Intrusive Reflow" by Coleman and Oxx. In this study 1:1.3 and 1:1.4 provided good results while greater than 1:1.5 gave voids or insufficient fill. I don't have information on Wave Solder process.

Bill Coleman
Bill Coleman
Vice President Technology, Photo Stencil
For over 18 years, Dr. Coleman has been the vice president of technology for Photo Stencil, working closely with customers to understand their printing requirements. His efforts have resulted in several new stencil products.
Submit A Comment
Comments are reviewed prior to posting. You must include your full name to have your comments posted. We will not post your email address.

Your Name


Your Company
Your E-mail


Your Country
Your Comments



Free Newsletter Subscription
Circuitnet is built for professionals who bear the responsibility of looking ahead, imagining the future, and preparing for it.

Insert Your Email Address

Sponsor
Circuit Technology Center
Expert Circuit Board Modifications
Need to make an engineering change without replacing your circuit board? Circuit Technology Center provides expert circuit board modifications, including trace changes, jumper wires, and component modifications.
Circuit Technology Center
M782 - Low Outgassing Adhesive