The majority of screening cans and fences currently on the market are manufactured in pre-tinned steel using pressed or stamping methods. Apart from the fact that non-ferrous materials should be used for high frequency applications, steel cans have a number of disadvantages which photochemically machined devices easily overcome.
A PCM screening can is generated by etching the outline from a sheet of metal. This simple and cost effective process offers many advantages over other methods:
- Incorporation of semi-etched fold lines allows for forming without
the need for special tools.
- Attachment tabs and slots can also be a part of the
design - especially useful for multi-compartment designs.
- Logos, part numbers or similar details can be etched at the same
- Mesh for venting can also be incorporated, usually at no extra cost.
- The can is easily shipped, stored and handled in the flat form
ready for quick assembly.
- Many shapes and sizes can be achieved.
- Variations such as multi-compartment cans or spring contact
between a box and lid are possible.
- No additional stress induced to the base material.
- With the exception of spring fingered lids, no hard tooling is used.
- All PCM manufacture is carried out with material in the raw
- Plating finishes are applied when all profiling is completed, so all
'machined' edges of the profile are fully protected with plating, and fully prepared for efficient soldering.
- Uniquely, the profile of the etched edge is 'W' shaped. The troughs
of the 'W' retain additional amounts of plating which further improves the ability of the screening device to be reflow soldered.