Wafer Processing, Inspection, and Identification
Wafers, also known as slices or substrates, are thin pieces of semiconductor material used in the manufacturing of photovoltaics, which convert light into electricity. Machine vision automates wafer handling; enables precision alignment; and inspects bus bars and AR coating to create thin, high quality wafers with a fine pitch. Quality inspections help manufacturers avoid wafers which are warped, flipped, chipped, contain saw marks, or display contour defects.
Solar PV Cell Fabrication
Cognex machine vision products monitor and inspect wet processing, metallization, firing, and color sorting for high quality PV cell fabrication. Industry-leading machine vision software detects cell orientation and cells defects; aligns PV cells for screen printing; inspects cells edges with laser edge isolation; sorts and grades cells by color; and performs back print and front print registration inspections.
Download: Solar Industry Guide
Download: Solar Panel Inspection Application Note
Solar PV Module Assembly
In the final step, many PV cells are assembled into strings and packaged into a single unit, called a module. Machine vision ensures accurate cell spacing, construction, and part placement during module assembly. During stringing alignment and inspection, machine vision centers the PV cells, minimizing the need for mechanical contact, and examines the cells for defects while also verifying the continuity and correct assembly of each string. Multiple modules may be assembled into a solar panel.
Industrial image-based barcode readers handle even degraded, reflective, or low-contrast marks from die backsides, substrates, encapsulated packages, and PCBs for complete traceability. Barcode readers reliably track parts and identify wafers, PV cells, and modules throughout production and assembly.
Cognex machine vision products monitor ingot formation, providing precise dimensional measurements during the crystal pulling process. The In-Sight 8000’s small form factor and robust edge detection tool ensure the crystal seeding, shouldering, shoulder circuiting, and diameter equalizing stages are performed to exacting standards for proper ingot formation.