Precision Lapping Services

A: Lapping is an abrasive machining process that uses loose abrasive particles suspended in a slurry between the workpiece and a lap plate to achieve exceptional flatness, surface finish, and dimensional accuracy. Unlike grinding (which uses bonded, rotating abrasives and can induce heat/stress), lapping is a low-pressure, low-temperature process. Unlike polishing (which primarily improves surface shine and may not correct geometry), lapping simultaneously corrects macro-geometry (flatness, parallelism) and refines micro-surface finish without directional lay.

A: We lap a vast range of materials, including: · Metals: Tool steels, stainless steels, carbides, aluminum, copper, and exotic alloys. · Ceramics & Advanced Materials: Alumina, silicon carbide, silicon nitride, zirconia, quartz. · Semiconductors: Silicon, germanium, gallium arsenide wafers. · Glass & Optical Materials: Fused silica, BK7, sapphire. · The process is particularly valuable for hard, brittle materials that are challenging to finish by other means.

A: Our capabilities are tiered based on application: · Standard Precision: Flatness within 2.5 µm (0.0001"), Ra down to 0.1 µm (4 µin). · High Precision: Flatness within 0.5 - 1.0 µm, Ra down to 0.025 µm (1 µin). · Ultra-High Precision (Optical/Metrology Grade): Flatness to < 0.1 µm (λ/10 light bands), Ra to < 0.012 µm (0.5 µin). Specific tolerances depend on part size, material, and initial condition.

A: We primarily use free-abrasive lapping (slurry), which offers the greatest flexibility, the best geometric correction capability, and the finest finishes. Fixed-abrasive lapping uses a pad or plate with embedded abrasives; it can be faster for specific applications but is generally less effective at correcting flatness. We select the optimal method based on your material, shape, and precision goals.

A: Yes. We offer double-sided (dual-face) lapping, which is a significant advantage. It simultaneously laps two opposite parallel faces of a part, ensuring perfect parallelism and eliminating the cumulative error and potential distortion that can occur from flipping and re-fixturing in single-sided processes. This is critical for components like seals, spacers, and wafers.

A: Thickness is controlled through a combination of:
1. Precise Initial Stock Allowance: We specify the optimal amount of material to leave for lapping (typically 0.025mm to 0.1mm per side).
2. Process Monitoring: Using in-process gauging and timed cycles based on established material removal rates.
3. Final Measurement: Verifying with high-precision micrometers, air gauges, or optical interferometers. We can hold thickness tolerances to within ±0.001mm or better for critical batches.