Blowholing in PTH Solder Fillets: Part 6 The Laminate, The Drilling and the Hole Wall Preparation

Abstract

The drilling and preparation of a hole in FR‐4 laminate prior to the deposition of electroless copper is considered in relation to the quality of soldering achieved on the finished printed circuit board. Data pertaining to the drill speed, drill feed, and stack position are presented and the effect of drilling temperature is demonstrated. The variability of laminate is discussed in relation to outgassing during soldering. Finally the importance of the post‐drilling treatment of the hole‐wall is shown. The relative effects of baking after drilling, ultrasonic cleaning and chemical treatments such as alkaline potassium permanganate are illustrated.

Citation

Lea, C. and Howie, F.H. (1986), "Blowholing in PTH Solder Fillets: Part 6 The Laminate, The Drilling and the Hole Wall Preparation", Circuit World, Vol. 13 No. 1, pp. 43-50. https://doi.org/10.1108/eb043855