Coherix’s Laser-Based Computer-Vision Improves Electronics Manufacturing

New tech confirms the proper application of sealant and adhesives.

September 9, 2024

Kami Buchholz

Coherix 3D Mini controls the adhesive dispensing applications for automotive electronics. (Coherix)

An industry-first 3D laser-based, computer-vision system can monitor and control the application of adhesive beads as tiny in width as two human hairs. This unique inspection system for electronic assemblies operates at speeds of 400 to 1,000 times per second, considerably quicker and more effective than conventional 2D systems.

The Coherix 3D Mini eliminates the need for manual inspection of adhesives on automotive electronics. Eric Henke, Coherix senior application engineer, is in the background. (Coherix)

“Difficulty in precisely dispensing adhesives or sealants, especially in extremely small or complex electronic assemblies, can lead to over-application, under-application, bubbles, or incorrect location of the adhesive bead,” Juergen Dennig, president of Ann Arbor, Michigan headquartered Coherix, told SAE Media. Improper application of joining material on electronic control units (ECUs) and power control units (PCUs) can result in poor adhesion, material voids and short circuits.

With its small footprint, the new Coherix 3D Mini system performs adhesive inspections inline, a cycle time-saver in comparison to post-assembly inspection systems. All production data is retrievable, providing part traceability for every assembled part. “This eliminates tearing apart a finished manufactured part to ensure the sealant/adhesive is in the correct location and meets location, volume and width specifications, a process that is often done two to three times per shift at manufacturers that currently do not use a robust inspection method,” Dennig said.

The 360-degree vision system uses Coherix’s proprietary i-Cite software, providing real-time 3D information about the height, width, volume, and position of the sealant/adhesive application. An intuitive user interface provides direct feedback to the operator about whether the adhesive application passes or fails, according to Dennig.

Patented Coherix adaptive process control software enables the system to correct variations of adhesive applications. For instance, if a material gap is found, the 3D Mini prompts the adhesion-applying robot to fill in the gap and avoid the necessity of scrapping the part for poor quality.

Dennig claimed Coherix’s 3D system can potentially reduce operating costs by up to 20%. “The beta test of the Coherix 3D Mini system demonstrated significant cost savings,” he said, adding that a major automotive electronics manufacturer estimates more than $160,000 in annual operating savings with the installation of eight 3D sensor systems on a single assembly line.

China is initially expected to outpace Europe and North America in usage of the new technology.“China’s rapidly expanding production of electric vehicles and other electronic products makes it the single largest potential market for this new technology,” Dennig said.