Etching and plating masking
Reduction in process steps and cost
The traditional process in chemical milling is illustrated below and visualized by the PCMI.
It is apparent that transferring the CAD design to the substrate before etching is crucial. The process steps between pre-treatment and etching are sensitive to contamination and therefore critical for product quality. So, they are carried out in a cleanroom environment, which is costly.
Applying inkjet printing of resist to photochemical milling simplifies the process, as illustrated below.
There is no more need for a photomask, including storage location, or for a dry-film photoresist. The relevant process steps are replaced by a single printing step.
It is clear that reducing the number of process steps has large benefits. Less equipment needs to be operated, which reduces amount of floor-space, consumables and workforce. Since artwork is handled digitally and no photomasks are needed, the lead time for products is reduced and the need for storage facilities for the photomasks vanishes.
Furthermore, inkjet printed resist eliminates the need for different sizes of dry-film and reduces waste of the resist material. While the inkjet process only deposits resist directly where it is needed, there is also no excess material to be cut away when the dry-film sheet is wider than the substrate.
The PiXDRO JETx inkjet production system is designed specifically for printing masking resist for chemical milling applications. This system enables cost-effective manufacturing of precision mechanical parts, meshes, gaskets, fluidic channel plates, decorative items, etc.
The JETx printer produces etch masks with the following specifications:
- Printing feature size: down to 3 mil (75 µm) traces and spaces
- Mask edge roughness: 10 – 20 µm (top-top)
- Alignment front/back mask: < ± 20 µm when using alignment w.r.t. the corners of the substrate
- Substrate size: up to 18 x 24” or 22.5 x 26”
- Printing speed: up to 50 or 80 sides/hr (full area)
- Quality control: continuous nozzle monitoring
Direct resist printing offers advantages to the chemical machining industry or its typical products (meshes, springs, washers, gaskets, fluidic channel plates, decorative items, name plates, etc.). It can also be applied to PCBs, heaters, power device and RF substrates, and in selective plating of electrical components.