Precision 6061-T6 Semiconductor Optical Inspection Module Base Housing with Coaxiality Control

We manufactured a precision 6061-T6 Aluminum base housing for a semiconductor optical inspection module. This component serves as the structural foundation for optical sensing systems — requiring precise alignment between the cylindrical outer wall and the internal cavity, as optical path integrity depends on geometric consistency between these features. Achieving and maintaining cylindrical-to-cavity coaxiality in aluminum housings is particularly challenging due to residual stress release during machining and thermal effects during subsequent Surface Treatment .

6061-T6 offers balanced strength and machinability, but its internal stresses from heat treatment can cause distortion when material is unevenly removed . For this component, we applied a staged stress-relief strategy: roughing with generous allowance, followed by 48-hour ambient stabilization to allow residual stresses to dissipate, then 5-axis single-setup finishing for both outer cylinder and internal cavity — eliminating re-fixturing errors that compromise coaxiality . The outer wall was finished with bead-blasting to remove tool marks and create uniform surface texture, followed by MIL-A-8625 Type III hard anodizing. Anodizing adds ~2-5μm per surface (accounts for ~4-10μm total on diameter), factored into finishing allowances to maintain final dimensional accuracy . The result: a base housing holding coaxiality tolerances for semiconductor-grade optical module integration.

Project Overview

Key Technical Highlights

• Coaxiality Through Single-Setup Strategy: 5-Axis Machining in a single fixturing setup ensures both the outer cylinder wall and internal cavity are referenced to the same datum — eliminating re-fixturing errors that cause coaxiality drift . For optical housings, research indicates machining must be completed in a single setup to maintain alignment-critical features .
• Stress-Relief Sequencing for Distortion Control: 6061-T6's internal stresses from heat treatment release unevenly during material removal. Applied staged roughing with 1-1.5mm finishing allowance, followed by 48-hour ambient stabilization at 20±1°C before finishing — allowing stress dissipation and preventing distortion .
• Surface Treatment Dimensional Control: Bead-blasting does not affect critical dimensions, but hard anodizing adds ~2-5μm per surface . Finishing allowances account for the ~4-10μm total added thickness on diameters, ensuring final dimensions stay within specification after treatment .

Quality Verification

CMM inspection verified cylindrical-to-cavity coaxiality, dimensional accuracy (±0.015mm), and flatness. Anodized coating verified for thickness (MIL-spec Type III) and uniform matte appearance. Coaxiality measured post-anodizing to confirm dimensional stability after surface treatment.

Industry Applications

Ideal for semiconductor optical inspection modules, precision optical housings, metrology equipment bases, and optoelectronic component mounts.

Why Partner With Us?

• Proven expertise in single-setup 5-axis machining for coaxiality-critical components
• Staged stress-relief protocols for post-machining dimensional stability
• In-house bead-blasting and hard anodizing with MIL-spec compliance
• 12+ years of precision manufacturing experience across semiconductor and optics sectors