1. Negative Film for Circuit Boards: Tenting Process

• Utilizes acid etching for negative film.
• Transparent areas represent the desired circuit or copper surface, while black indicates unnecessary portions.
• After exposure and development, only the hardened dry film is etched, leaving the desired circuit on copper foil.

2. Positive Film for Circuit Boards: Pattern Process

• Employs alkaline etching for positive film.
• The circuit or copper surface is visible as black when viewed from the negative film.
• After exposure, chemical hardening, development, and tin-lead plating, the circuit is revealed by etching the unprotected copper surface.

3. Process Variations: Positive vs. Negative Films

• Positive film process involves cutting, drilling, PTH, circuit creation, and SES Line.
• Negative film process includes cutting, drilling, PTH, line creation, and DES Line.

4. Distinguishing Master and Working Films:

• Master film is black, used for copying work film.
• Working film can be yellow or black, with yellow commonly used for ordinary board production.

5. Light-Transmitting vs. Opaque Films:

• Light-transmitting negative film is used for direct etching, developing a circuit for acid etching.
• Opaque positive film is used for pattern plating, leaving a circuit for anti-corrosion electroplating.

6. Medicinal Film Distinguishing:

• Black and smooth surface indicates medicinal film.
• Yellow film is the opposite, with matte surfaces prone to oil indentation.

7. WellCircuits Introduction:

• WellCircuits specializes in high-precision circuit boards, including HDI, thick copper, backplanes, rigid-flex, buried capacitance, and Gold Finger boards.