Patent ID: 11914297
Assignee: TAMAPOLY CO., LTD.
Field: Surface technology, coating (Chemistry)
Classification: CPC G  B  C | IPC B  C  G

Claim 0:
1. A cover film for dry film resist, comprising:
a polyethylene film comprising three layers consisting of one layer A and two layers B, the layer A being positioned between the two layers B,
wherein the layer A comprises a first mixture of high pressure low density polyethylene (LDPE) and linear low density polyethylene (LLDPE), the first mixture having an LDPE to LLDPE ratio by mass of 90:10 to 60:40,
wherein the layer B comprises a second mixture of high pressure low density polyethylene (LDPE) and linear low density polyethylene (LLDPE), the second mixture having an LDPE to LLDPE ratio by mass of 100:0 to 80:20,
wherein a content of the linear low density polyethylene (LLDPE) in the first mixture is higher than a content of the linear low density polyethylene (LLDPE) in the second mixture,
wherein the polyethylene film is free of a plasticizer, anti-blocking agent, slipping agent, and anti-static agent,
wherein the number of fish eyes having a minimum diameter of 0.2 mm or greater in the cover film in plan view is at most two based on the number per 100 m2 of the cover film having a thickness of 19 μm, and
wherein the polyethylene film has a thickness of 10 to 20 μm and a haze value of 12 to 25%.