This article is intended for anyone who isn’t yet familiar with how to evaluate the quality of BGA solder joints from cross-section images.
Workingbear happens to have several cross-sectional photos from actual production boards that make excellent teaching examples. Among them are some very typical defects, including Head-in-Pillow (HIP) solder joints and solder balls that were stretched during assembly, resulting in weak solder connections.
During new product development meetings, We often hears project managers (PMs) asking mechanical engineers (MEs) to confirm the CMF with the Industrial Design (ID) and Marketing teams before moving forward with tooling development. Otherwise, it could even affect the mechanical design itself. So, what exactly does CMF mean?
A new management team often brings new management methods. Recently, a new term, POC, started appearing in Workingbear’s new product development meetings. POC stands for Proof of Concept, which simply means verifying whether a concept or idea is technically feasible.
In simple terms, the main purpose of a POC is to validate whether engineers’ concepts, theories, or innovative ideas can actually be implemented. During new product development—especially for completely new or breakthrough products—it is essential to confirm that the core concept is feasible before the entire development team moves forward. Otherwise, a company may spend a significant amount of time and money completing a product design only to discover later that the idea cannot be manufactured or the technology does not work as expected.
WIP stands for Work-in-Process (or Work-in-Progress), which refers to products that are currently going through the manufacturing process but have not yet been completed. In a broad sense, WIP can include semi-finished goods that have already completed certain manufacturing steps. In a narrower sense, however, WIP refers specifically to products that have not yet reached the semi-finished stage.
In many electronics manufacturing factories, a product can be considered WIP as soon as the kitting process begins. Once the product has completed all assembly operations, is packaged, passes OOB (Out-of-Box) or OQC (Outgoing Quality Control) inspections, and is officially transferred into finished goods inventory, it is classified as FGI (Finished Goods Inventory).
Many manufacturing professionals aren’t exactly excited when they’re assigned to a new product pilot build. Pilot production is often complex, fast-paced, and difficult to measure in terms of productivity or performance. Schedules are usually tight, and in the early stages, even the Bill of Materials (BOM) may not be fully finalized. Many tasks still require manual work, and new manufacturing processes often need time to be refined and stabilized.
The challenges don’t stop there. New products typically introduce new components, many of which arrive as bulk parts or tube-fed components instead of production-ready reels. This can create headaches for SMT assembly lines, forcing operators to place parts manually before the boards can enter the reflow oven. The situation is often even more labor-intensive during final assembly, where a significant amount of manual work may still be required.
