We search for industry news, so you don't need to.
Ask the Experts  
Questions Index  ■  Submit a Question  ■  Experts Panel  ■  Join the Panel

April 30, 2007

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?


Experts Comments

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
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

Your Name

Your Email

Company Name




Please type the number displayed into the box. If you receive an error, you may need to refresh the page and resubmit the information.