Customer Background and Production Sampling Requirements

This case involves an advanced electronics manufacturer in Taiwan requiring cross-sectional inspection of multilayer structures containing copper as a primary conductive material. Due to confidentiality agreements, the customer's identity, product images, complete material composition, and exact workpiece dimensions are not disclosed.

The customer needed to collect samples from production batches and examine the internal copper layer arrangement, bonding conditions, and visible defects such as delamination or cracking as part of its quality inspection process.

With more than ten product models requiring different positioning arrangements, the solution also needed to support multiple workpiece configurations while maintaining cutting efficiency and ease of operation.

Minimizing Cutting Damage to Multilayer Structures

The customer initially used conventional saw blades and diamond wire cutting equipment for cross-section preparation. However, these methods caused material dragging and interlayer separation, potentially affecting the accuracy of subsequent inspection.

Unlike conventional mechanical cutting, Wire EDM removes conductive materials through controlled electrical discharges, without direct contact between the cutting tool and workpiece. This significantly reduces mechanical forces acting on delicate multilayer structures.

Although initial Wire EDM trials eliminated mechanical dragging, some interlayer delamination remained. JSEDM engineers therefore focused on optimizing cutting direction and discharge parameters to achieve acceptable cross-sectional quality.

Fig. 1 | JSEDM Wire EDM machining and fixture manufacturing (not the customer's product)

Cutting Trials and Precision Cross-Sectional Measurement

Fig. 2 | In-house precision measurement supporting cross-sectional analysis

JSEDM conducted multiple cutting trials to evaluate different cutting orientations and machining conditions. The in-house KEYENCE VK-X3000 precision measurement system was used to examine cross-sectional appearance and interlayer integrity.

Initial tests showed that cutting parallel to the layer stacking direction required a shorter machining path but was more likely to cause delamination. Cutting perpendicular to the layers avoided this issue, although it required a longer cutting path and additional machining time.

Through repeated testing and optimization of discharge conditions, feed settings, and flushing, JSEDM successfully achieved acceptable cross-sectional quality using the shorter parallel cutting path. In-house measurement also enabled faster evaluation and process adjustments.

Universal Fixture Design for Over Ten Product Models

The customer required regular cross-sectional inspection of more than ten product models, each with different dimensions and positioning requirements. Developing a separate fixture for every model would increase costs and complicate daily operations.

Based on the workpiece dimensions and required cutting directions, JSEDM developed and tested a custom universal fixture compatible with more than ten product models. Its positioning design allows operators to switch between models simply by replacing the workpiece.

No fixture replacement or readjustment is required during model changeovers. Combined with established machining parameters, this solution simplifies workpiece setup and supports a more standardized production sampling inspection process.

Fig. 3 | Universal fixture supporting cross-sectional inspection of over ten product models

Improving Cutting Efficiency and On-Site Operations

For production sampling inspection, both machining efficiency and cross-sectional quality are essential. Rather than pursuing the lowest possible surface roughness, JSEDM optimized cutting conditions according to the customer's actual inspection requirements.

The final process used a standard Ø0.25 mm electrode wire with a single cut (1 Cut), achieving approximately 15–20 minutes per workpiece. Compared with cutting perpendicular to the layer stacking direction, machining time was reduced by more than 50%, while maintaining acceptable cross-sectional appearance under the tested conditions.

During Wi-200S installation, JSEDM engineers worked directly with the customer's operators to review workpiece clamping and machining procedures. Based on actual operating conditions, the fixture was further refined to improve usability and support routine inspection.

From Process Validation to Production Inspection

Through cutting direction comparisons and EDM parameter optimization, JSEDM successfully improved the interlayer delamination observed during initial trials. The final cross-sections were visually inspected and accepted by both JSEDM and the customer, meeting the required inspection criteria.

In addition to machining optimization, JSEDM delivered a universal fixture supporting more than ten product models. This allows operators to perform sampling inspections without repeatedly changing or adjusting fixtures, improving consistency and ease of operation.

From initial cutting trials and precision measurement to fixture development and on-site adjustments, JSEDM provided integrated engineering support throughout the project. The Wi-200S has now been successfully installed and integrated into the customer's routine production sampling inspection process.