2024年4月11日发(作者：)

pcb正片和负片工艺流程

英文回答：

PCB (Printed Circuit Board) manufacturing involves two

main processes: the positive photoresist process and the

negative photoresist process. Both processes are used to

create circuit patterns on the PCB.

Positive Photoresist Process:

1. Substrate Preparation: The PCB substrate, usually

made of fiberglass or composite materials, is cleaned and

prepared for the subsequent steps.

2. Photoresist Coating: A layer of positive photoresist

material is applied onto the substrate using a spin coating

technique.

3. Prebaking: The coated substrate is heated to remove

any solvent and to ensure the uniformity of the photoresist

layer.

4. Exposure: The PCB artwork, which contains the

desired circuit pattern, is aligned and placed on top of

the coated substrate. The assembly is then exposed to UV

light.

5. Development: The exposed substrate is immersed in a

developer solution, which selectively removes the unexposed

photoresist, leaving behind the desired circuit pattern.

6. Etching: The exposed copper areas on the substrate

are etched away using an etchant solution, leaving behind

the circuit traces.

7. Stripping: The remaining photoresist is removed from

the substrate using a stripping solution.

8. Inspection and Testing: The PCB is inspected for any

defects or errors in the circuit pattern. Electrical

testing may also be performed to ensure the functionality

of the circuit.