Preparation and performances of coated and aluminous entry boards with endothermic and lubricant resins for PCB drilling

Abstract

Purpose

The purpose of this paper is to provide a new entry board for drilling holes on the PCBs, superior in heat removal effect, lubricating effect and hole locating effect in forming holes, resulting in an excellent process of forming holes with a high quality.

Design/methodology/approach

With the mixture of PEG, PEO and adhesive used as endothermic and lubricant resins and aluminium foils used as baseplates, a series of coated and aluminous entry boards (CABs) for PCB drilling were successfully prepared. Scanning electron microscopy (SEM) was employed to observe the surface appearance of the entry boards. The endothermic and lubricant effect of the resin applied on the CABs was characterized by differential scanning calorimetry (DSC) and polarizing microscope (POM). Moreover, the CABs' good drilling properties were tested when they were used for PCB drilling.

Findings

From the result of SEM analysis, it was found that compared to the common aluminium foil, the surfaces of the CABs were smoother and flatter, which could improve the hole location accuracy and reduce the drill breakage. By means of the DSC and POM, the endothermic and lubricant effect of the CABs was proved. The crystalline substances (PEG and PEO) in coated resin could absorb the heat of the drill bit from heat generation and lubricate it through the phase transition of they own when a hole was being made, which could give high‐quality holes with good production efficiency. The drilling tests showed that due to the endothermic and lubricant resins, the CABs were superior to the common aluminium foil, not only in hole location accuracy, but also in hole wall quality and protection of a drill bit.

Originality/value

This paper has a remarkably high industrial practicality in the PCB manufacture process.

Citation

Zhou, H., Xun, R., Liu, Q. and Wu, P. (2013), "Preparation and performances of coated and aluminous entry boards with endothermic and lubricant resins for PCB drilling", Circuit World, Vol. 39 No. 3, pp. 139-146. https://doi.org/10.1108/CW-03-2013-0007