Photo-Chemical Machining Process
After ensuring that the metal to be etched is clean, it is coated with a polymer resin-based photo-sensitive resist. The coated sheet is then exposed to ultra-violet light through the photomaster created by the CAD system, from both sides, hardening the photo-resist where exposure takes place.
The unexposed areas are chemically developed away removing the resist, leaving the bare metal where etching will occur. Etching solution is sprayed at pressure to the top and bottom surfaces, removing the unwanted metal very accurately and producing the component. The remaining resist is then removed from the sheet of components.
Materials processed
- Aluminium
- Berylium Copper
- Brass
- Copper
- Mild Steel
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- Phosphor Bronze
- Nickel
- Spring Steel
- Stainless Steel
- Super Alloys, including: Jetfire, Waspalloy, Haynes, Rene, and some Hastelloys such as Inconel and Incalloy
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Forming
Attewell has a range of equipment to carry out forming of a number of etched products.
Surface treatments
Attewell has partnerships with a number of treatment houses catering or aerospace or commercial applications.
Typical products manufactured using Photo-Chemical Machining
- Shims
- RFI Screening Products
- Lead Frames
- Contacts
- Screens
- Radial & Axial Springs
- Iris Leaves & Graticules
|
- Valve Plates
- Heat Sinks
- Solder Paste Masks
- Watch Parts
- Encoder Discs
- Filtration Products
...and many more
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Achievable Tolerances
| Metal Thickness mm |
0.025 |
0.125 |
0.250 |
0.500 |
1.000 |
| Dimensional Accuracy +/- |
0.010 |
0.015 |
0.025 |
0.050 |
0.100 |
| Minimum Hole Size |
0.040 |
0.175 |
0.375 |
0.750 |
1.500 |
| Minimum Corner Radii |
0.025 |
0.125 |
0.250 |
0.500 |
1.000 |
| POSITIONAL |
| Pitch |
25 |
125 |
250 |
500 |
1000 |
| Accuracy +/- |
0.012 |
0.025 |
0.050 |
0.075 |
0.10 |
Low-cost tooling
Since the main ‘tool’ for PCM is a CAD drawing, the costs are relatively low and, furthermore, can be produced quickly. Drawings can be accepted electronically via e-mail in the following formats: IGES; DXF; and DWG.
Low-cost modifications
Modifications to the requirement can be accommodated relatively easily and with little costs. Small batch sizes can be economically produced.
Prototype to Production
Whether just one or a large number of parts, the same tooling can be used every time. This allows the engineer or designer to develop concepts from prototype and pilot to full production with relative ease.
Metal properties
PCM carries the unique advantages of leaving the hardness, grain structure and ductility of the metal unchanged.
Burr free
The PCM process produces burr-free components, thus removing the need for costly time-consuming de-burring.
Identification marks
Company logos, part numbers and other identifying marks can be etched into the surface during manufacture at no extra cost.
Precision & Intricacy
Very precise and intricate components can be produced that would confound other manufacturing processes.