Thick Film Resist

The resist used in the front-end process is designed to develop the circuit pattern transferred to the underlying substrate through the patterned resist photolithography process. These advanced photoresist materials enable current manufacturing and production equipment to produce next-node products, thereby realizing your mobile lifestyle.

Alfa Chemistry provides our customers with professional thick film resist solutions. Contact us for more information.

Fields of Application for Thick Resist

During the exposure process, the typical high photoactive compound concentration in thin resists makes it difficult to fully expose thick films made using "thin resist". Suitable thick resists have high viscosity and low absorbency to allow formation and exposure through thick films.

Fig.1 UV-patterned sample structure of four multi-laminated layers of TMMF S2045 dry-film resist. (Wangler N, et al. 2012)

In order to achieve a high metal structure, electroplating usually requires a resist film thickness of 10 μm and above. In micro-optics or microfluidics, the structure is usually realized by transferring a reflowed spherical or cylindrical resist structure into a substrate via dry etching. For this reason, a thick resist film is required in many cases. Deep dry etching also requires a certain thickness of resist film.

What Can We Offer?

We provide a variety of thick film resists, from traditional DNQ and chemically amplified positive polarity to photopolymerization negative polarity, which can be used to make patterned conductive circuits in semiconductor packages.

Our products include, but are not limited to, the following:

• 4000 Series
• P4000 Series
• TF5000X Series
• 125nXT Series
• IPS Series
• 3DT Series
• PLP Series

Since the exposure time depends on the thickness of the resist, accurate measurement is required. In addition, since positive photoresist and negative photoresist can be used together to create complex multilayer MEMS structures, it becomes extremely important to understand the thickness of each layer. Alfa Chemistry is particularly good at measuring thick resists, even resists that are opaque in the visible light region. For photoresist measurements, please contact our thin-film experts.

We can measure the thickness of single-layer, multi-layer, and even free-standing photoresist films from 1 nm to 3 mm for customers. All models measure thickness by accurately modeling spectral reflectance. Test results can usually be obtained quickly.

Our capabilities include:

• Do not use the measuring light source to expose the resist
• Can access the refractive index library covering a wide range of photoresists
• Ability to cope with the tendency of photoresist to change with the degree of baking and exposure

Benefits of Working with Us

The benefits of working with us are self-evident:

• Sustainability
• Leading position for TFR
• Low-cost solution
• Total solutions for various applications
• Very professional technical service

Reference

1. Wangler N, et al. (2012). “Ultra Thick Epoxy-based Dry-film Resist for High Aspect Ratios.” Microelectronic Engineering. 97: 92-95