There is a time-worn maxim in micro manufacturing, you can’t make it if you can’t measure it. Isometric Micro Molding takes that one step further- you can’t make it if you can’t validate it. It is vital to know that the part that has been manufactured is statistically capable of tolerances as initially designed, and the smaller the parts of features on parts, the harder and harder this becomes.
At Isometric Micro Molding, precision is central to everything that we do, and because of this we employ the use of an in-house high resolution CT scanning facility to verify that design intent is achieved. Use of CT scanning allows us to detect deviations in the actual molded or assembled part against original 3D CAD design data down to 0.1 micron (4 millionths of an inch) in all axes.
The CT scanner software generates a point cloud file, which is effectively a visible and explorable 3D representation of the physical molded part. This 3D point cloud is then compared visually to the CAD solid model of the part, and a color deviation plot is produced showing just how close the finished product is to the original design.
All this may seem somewhat extreme, a bit of a sledge hammer to crack a nut, but experience has shown us that it’s really the only way to ensure repeatability and reproducibility of finished micro molded components and assemblies. Without this in-house capability, micro molding companies will struggle to validate and optimise processes and outcomes for their customers.
Metrology and Gage R&R are perhaps the most challenging aspects of micro molding, where it is common to have more error in the measurement than in the actual parts. It is vital for us to obtain timely and accurate metrology data, and CT scanning provides a full CAD model of the part in less than 10 minutes — the visual CAD model being far more useful to a process engineer than lists of numbers on a page.
In addition to precise measurement, CT scanning also provides critical “assembly bonding layer” data that cannot be obtained through destructive analysis, and helps to detect bonding layer defects such as bubbles, voids, and improper bonding material distribution over the micro surface. The 3D images exported from the CT scanner are MRI-like in quality, and can depict an internal wall thickness view of the parts or assemblies that could not otherwise be obtained during validation or production.