Key Differences Explained
In printed circuit board (PCB) manufacturing, photoresist selection plays a critical role in achieving accurate circuit patterns and long-term reliability. At XPtronics Inc., understanding the differences between negativeand positive photoresist helps us choose the right process for each application, ensuring consistent, high-quality results.
What Is Photoresist?
Photoresist is a light-sensitive material applied to a PCB surface. When exposed to UV light through a photomask, it defines which areas of copper will remain and which will be etched away.
Positive Photoresist
With positive photoresist, the areas exposed to UV light become soluble and are removed during development.
Key advantages:
- Higher resolution and finer feature definition
- Better suited for dense, complex circuit layouts
- Easier inspection due to clearer pattern definition
Common applications:
High-density interconnects (HDI), fine-pitch designs, and advanced PCB technologies.
Negative Photoresist
In negative photoresist, the UV-exposed areas become hardened, while the unexposed areas are removed.
Key advantages:
- Strong adhesion and durability
- More resistant to mechanical stress
- Cost-effective for simpler layouts
Common applications:
Thicker copper layers, power electronics, and less complex PCB designs.
Choosing the Right Photoresist
The choice between negative and positive photoresist depends on design complexity, copper thickness, resolution requirements, and end-use conditions. At XPtronics Inc., we evaluate each project individually to select the optimal photoresist process that balances performance, reliability, and cost.
XPtronics Inc. Expertise
Our PCB manufacturing and assembly expertise ensures precise imaging, controlled processing, and reliable outcomes—whether your design demands ultra-fine features or rugged performance.
Need guidance on PCB fabrication or PCBA?
Contact XPtronics Inc. to learn how our engineering-driven approach can support your next project.
