Identify the areas of variance in stencil design and adjust SPI programming accordingly.
Deep dives on defect resolution, one at a time.
Most medium-to-high volume electronics manufacturing services (EMS) providers design their new product introduction (NPI) process to identify issues in printed circuit board (PCB) layout, overall product design or process flow that create defect opportunities. Unfortunately, a key challenge in the EMS industry is convincing customers to adopt those recommendations. Additionally, some design or process issues escape NPI or pilot production, not becoming evident until a product is running at full volume. SigmaTron International’s team in its Acuña, Mexico, facility is working to change those dynamics one customer at a time.
Improving problem identification and resolution speed through dual disciplines.
Teams at multiple SigmaTron International facilities have been trained in Lean Six Sigma philosophy. However, some companies work from a pure Lean manufacturing philosophy without Six Sigma tools. This month, we look at the benefits of integrating these disciplines.
The horizontal report provides a supply vs. demand “map” showing where shortages will hit.
At its foundation, Lean manufacturing philosophy is designed to eliminate waste and the associated chaos that inefficiency creates. Many of the core elements that improve factory efficiency, such as visible flow of work-in-process, small lot sizes, a strong focus on minimizing variation and poka-yokes to eliminate defect opportunities, have parallels that can increase efficiency in support organization tasks.
One of the most challenging tasks in the electronics manufacturing services (EMS) world is program management. This normally complex job has been made even more difficult by electronic component shortages that have been endemic since January 2021. As experts are predicting that component supply/demand imbalances are likely to continue through 2023, finding ways to eliminate inefficiency and waste is as important in program management as it is in production.
Correlating inspection trending with test data to fine-tune accept/reject parameters.
Industry 4.0 automated inspection technology opens the door to enhanced levels of process control. In addition to having to upgrade equipment, however, fully leveraging the power of this technology requires a strong team, an accurate program validation database, and a methodology to track trends in continuous improvement activities. Here is a look at an implementation process for inline 3-D solder paste inspection and 3-D automated optical inspection following reflow on SigmaTron’s SMT lines in Tijuana.
A planned phase two of this implementation includes adding 3-D AOI to secondary assembly operations post-SMT, plus correlating AOI trending with final test data to fine-tune AOI acceptance/rejection parameters. The facility is currently averaging 50ppm defect rates across its SMT lines. The goal of this greater inspection process is to drop that to zero defects; although, given material constraints are driving a defective component rate that represents a third of that 50ppm level on some programs, zero ppms may be unachievable until material availability returns to normal.
Lean Six Sigma training leads to effective, intrinsic problem-solving.
Much has been written on the “how” of Lean Six Sigma. This column discusses the “why” behind Lean Six Sigma. SigmaTron’s facility in Tijuana, Mexico, began implementing its Lean Six Sigma program in 2018 as a way to instill a focused process improvement methodology in its automotive and medical customer projects. A consultant was brought in for initial training, and I volunteered to be the internal champion after agreement that the necessary management support and resources would be put in place. The initial training sessions were designed to train the engineering team as Green Belts and select production personnel as Yellow Belts.
One challenge in an electronics manufacturing services company is each customer has control of their design. While some incorporate EMS-driven design for manufacturability (DfM) recommendations, others do not. Although SigmaTron’s production personnel wanted to solve production problems as they arose, the root causes were often difficult to identify using basic quality tools such as pareto charts without a strong problem-solving methodology. With Lean Six Sigma training, the team evolved from engineers and technicians trying to fix problems to a cohesive team with the necessary tools to rapidly identify issues, brainstorm possible root causes, test hypotheses, and implement the best solution. Issues that had taken weeks to analyze with prior methods were addressed in days or hours.