Essential Photo Etching Considerations: Bevels & Metal Thickness

Part 3 of 3

In the last two posts, we’ve discussed how metal thickness affects hole size and the line widths of photo etched designs.

For those who haven’t read the previous posts, these articles serve to help design engineers maximize the efficiency of their photo etching process. Like other metalworking processes, photo etching has a few tricks for getting optimal results.

In this blog post, we’ll discuss the relationship of bevels to metal thickness.

How Metal Thickness Affects Bevels

During the etching process, the etchant erodes material laterally as well as vertically. The result is what we call a “bevel”. This looks like a small concave slope at the edges of the photo etched holes.

There are two types of bevels we can create:

Etching One Side ​

As a rule of thumb, for a material with a thickness t, the bevel A would be approximately .4t.

Etching Two Sides

Assuming the material is being etched equally from both sides, the bevel is seen to be appreciably reduced.

As a general rule, when etching from two sides, the bevel A is approximately .2t.

Conclusion

Considering the relationship of the bevel to metal thickness is good practice when designing parts for photo chemical etching. These rules of thumb should help engineers create designs that are optimized for the photo etching process. 

Advanced photo etching tips design engineers should know.