Implementing Inkjet Solder Mask: A Customer Success Story

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One of the most significant advancements in PCB manufacturing in recent years has been the shift from traditional solder mask processes to digital inkjet technology. This transition offers clear benefits in performance, usability, and production efficiency.

This article presents a case study of a PCB manufacturer that successfully implemented inkjet technology for solder mask application, realizing significant gains in quality, cost savings, and yield by overcoming the limitations of traditional methods.

The Challenge: Limitations of the Traditional Solder Mask Process

Before adopting inkjet technology, the PCB manufacturing customer relied on the traditional liquid photoimageable (LPI) solder mask application process. This multi-step workflow—coating, drying, exposure, development, and final curing—was time-consuming and required significant manual handling. Material waste was common, with excess solder mask ink lost during screen or curtain coating, from overspray, and when cleaning.

Solder mask would often flow into through-holes and vias, resulting in production challenges. Mask misalignments could occur during the manual or partially automated alignment process in the exposure step. Such misalignments would lead to registration errors and were often made worse by limited compensation for material variations. Additionally, our customer experienced defects caused by air bubbles, under-curing, and contamination from films or the surrounding environment, resulting in frequent rework and increased costs.

Lengthy changeover times were another drawback, as switching between jobs necessitated changing screens or films, which contributed to downtime and lower productivity. The process presented waste management challenges, because it involved phototool films and solvents, and the release of volatile organic compounds during curing. Additional operational challenges included cleaning chemicals, and high water and energy consumption.

To continue reading this article, which originally appeared in the December 2025 issue of PCB007 Magazine, click here.