Metal in Microns: Fab 5 of Micro Metal Fabrication (Photo Chemical Etching)

CONCORD, ON, CANADA, February 20, 2013

(www.shimifrez.com) The fastest response time and lowest photo tooling costs make precision photo chemical machining ideal for both prototyping and medium / large production quantities. Instead of stamping, or laser cutting Photo Chemical Etching produces highly accurate and identical components for small and large batches. Chemical etching has No effect on magnetic properties, or deformation whether internal stresses or thermal, resulting a Burr free component.

Here are some tips to design your etched parts:

DIMENSIONS HOLES / SLOTS
Generally, the diameter of a hole or the width of a slot cannot be less than the metal thickness. This relationship varies as the metal thickness changes.

INSIDE CORNER RADIUS
The smallest inside corner radius is directly proportional to the metal thickness. The outside corner radius will be at least 0.75 X of the material thickness. Generally, the width of a finger or web cannot be less than the metal thickness.

TOLERANCES, Centre to Centre
Generally, the tolerances are a result of the stability of the photo tooling material. Consult the factory for information on alternate tooling materials.
Centre to Centre
C/C Dimensions (inches) Tolerance Attainable
_1.0" ±.0005"
1.0" - 3.0" ±.0010"
3.0" - 6.0" ±.0020"
6.0" - 10.0" ±.0030"

PHOTO ETCHED DIMENSIONS
Generally, a tolerance of ± 10 to 15% of the material thickness is practical.

TABS
In most cases, your part will be etched from a sheet of metal. Parts are held in sheets by several small tabs which may leave a burr when detached. It is important to note that this burr is unlike a stamping/progressive die punching burr.

External Tabs
External tabs will produce a break-off point that will leave a small part of the metal sheet on the part.

Recessed Tabs
Recessed tabs are similar to external tabs except that the break-off point will be recessed into the part. Using this option if your part cannot have any areas extend beyond its perimeter. Typical applications that use the recessed tab are parts such as encoder discs and other circular parts and shields.
RFI/EMI board level shields will use recess tabs so that the tab does not affect the fence's attachment to the circuit board.

Services & Capabilities.
We provide precision photo chemical etching services for a variety of applications. Whether you are in the aerospace industry or medical device manufacturer or micro-electronics or telecommunications need other
consumer applications, we have the capabilities to help.