photochemical machining process is a widely used production technique that involves the creation of thin metal parts, with high precision, using chemical etching. It is also known as photo etching, chemical milling, and photofabrication. It is a valuable industrial process that’s responsible for the production of numerous parts for different industries.
This process has been in use since the 1960s and has revolutionized the production of metal parts worldwide. The process involves the use of photosensitive materials to produce extremely accurate and high-quality metal parts in a simple and fast way. Photochemical machining has over the years, led to the production of more intricate and highly precise miniature parts that would have been impossible to produce using traditional methods.
Because of its high accuracy and repeatability, photochemical machining process is ideal for small to medium production runs. The production speed of the process allows for the quick turnaround of parts and also ensures accuracy and precision that will match any part produced using traditional methods.
How the photochemical machining process works
Photochemical machining takes a similar approach to creating PCBs (Printed Circuit Board). The process starts with thin sheets (up to 2mm) of the desired metal (such as brass, copper, stainless steel, etc.), which are coated and laminated with photoresist. The photoresist serves as a protective layer and ensures that any free metal ions within the sheet are neutralized.
The coated sheets are then placed in a machine called a plotter, where the design of the required component is printed onto the photoplotting film. The film is then placed on top of the photoresist-coated sheet, exposing it to bright UV light. This causes the parts of the photoresist that are exposed to the light to harden, while the covered parts remain soft.
The sheet is then submerged in an etchant solution (usually ferric chloride for copper alloys), which will dissolve any exposed metal. It is essential to note that each metal type requires a specific etchant solution. The parts of the sheet that remain covered by the hardened photoresist will be protected from the etchant solution, allowing intricate designs and components to form.
Once the required components have been formed, the sheet is washed to remove the photoresist and any residual etchant solution. At this point, the required metal parts can be further processed, including plating, annealing, and surface finishing.
Advantages of the photochemical machining process
1. High precision: The photochemical machining process is incredibly accurate, with tolerances of up to ±0.02 mm. The high precision allows for the creation of intricate and highly complex parts that are impossible to produce using traditional methods.
2. Low tooling cost: A significant advantage of this process is the low tooling cost associated with it. Unlike traditional methods that require a specific tool for each component, in photochemical machining, adding a new design is as simple as creating a new photoplotting film, significantly reducing set-up costs.
3. Chemical resistance: photochemical machining process creates components that have good chemical and corrosion resistance, making them suitable for use in harsh environments.
4. Customization: Another benefit of photochemical machining is its ability to produce unique designs and shapes. The process is highly adaptable and allows for customization to meet the specific requirements of any industry.
5. Fast delivery: photochemical machining process has a quick turnaround time, and freshly produced parts can be delivered within a week.
Limitations of photochemical machining process
1. Limited material thickness: This process can only produce components up to 2mm thick.
2. High initial cost: The initial cost of setting up photochemical machining can be significant, and it may not be feasible for small production runs.
3. Design complexity limitations: Highly complex designs may not be feasible with this process. However, this largely depends on the skill level of the design team.
The photochemical machining process is ideal for the production of small to medium metal parts with intricate designs. It offers high precision and accuracy with a fast turnaround time. However, it does have limitations, such as the material thickness and initial cost. It is an excellent option for industries requiring custom and unique designs while demanding high-quality production with short delivery times.
In conclusion, the photochemical machining process is an essential and widely utilized manufacturing technique. It has revolutionized the production of small to medium precision metal parts. Companies operating in industries such as aviation, electronics, pharmaceutical, and medical can take advantage of the many benefits offered by this process. By providing fast delivery times, customization, and high production accuracy, the photochemical machining process has become a formidable production method.