■157SD keeps the anti-adhesion layer intact, even under solvent attack, and allows you to easily peel off the mask, even against a liquid resist with strong tacking capability.

Some halogen-free liquid photo resists or those for packaging substrates contain special solvent.

This solvent removes the anti-adhesion layer from the photo mask protection film and, resultantly, earlier tape replacement is unavoidable.

The TACKWELL 157SD withstands such solvent attack to retain the anti-adhesion layer and extensively improve the durability of the tape. This minimizes the replacement of protection film while the liquid resist is being used. In addition, 157SD is superior in optical performance and provides the best solution for high-density packaging substrates such as BGA.

Study on elimination of anti-adhesion layer

■Evaluation methodAfter the specified number of exposure cycles is provided, the load used to separate the photo mask (to which the protection film is adhered) and the substrate is measured.

Evaluation of photo mask haze

■Evaluation methodAfter the specified number of exposure cycles is provided, the haze of the photo mask is measured.

■Sekisui's evaluation method (adhesion and exposure evaluation method)The substrate is exposed to UV repeatedly under the actual conditions to evaluate the adhesion.

Resist	AUS308 of Taiyo Ink Mfg.
Substrate	0.8mm thick glass epoxy substrate with both faces coated with 35-um thick
Vacuum adhesion	75 cmHg x 1 min

*The above figures are only measurements; their values are not guaranteed