The Application of Ethyl Lactate in Photoresist

What is photoresist？

Photoresist, is a light-sensitive mixed liquid composed of three main components: photosensitive resin, sensitizer and solvent. Photoresists can be classified into three types:

 

①Photopolymerization type, which uses vinyl monomers to generate free radicals under the action of light, and the free radicals further initiate the polymerization of monomers, and finally generate polymers, which have the characteristics of forming a positive image.

②Photo-decomposition type, using materials containing quinone azide compounds, after exposure to light, a photo-decomposition reaction will occur, changing from oil-soluble to water-soluble, and it can be made into a positive adhesive.

③Photocrosslinking type, using polyvinyl alcohol laurate as a photosensitive material, under the action of light, the double bond in the molecule is opened, and the chain is crosslinked to form an insoluble network This is a typical negative photoresist.

The application of photoresist

1.Analog Semiconductors；

2.Light-Emitting Diodes LEDs；

3.Microelectromechanical Systems MEMS；

4.Solar Photovoltaics PV；

5.Microfluidics & Biochips；

6.Optoelectronics/Photonics；

7.Packaging.

The application of ethyl lactate in photoresist

Ethyl Lactate is mainly to replace NMP(N-Methyl-2-pyrrolidone)

1. As a cleaning solution for photoresist, Ethyl Lactate can replace NMP.

The application of photoresist in the IC industry, As there is an integrated circuit, it will have photoresist. In addition, in the process of using photoresist, it has a process of cleaning excess photoresist. The cleaning process is to clean with water and alkaline solution after etching with photoresist, but before cleaning with water and alkaline solution, there has an intermediate transition process, which used to be cleaned with NMP, but due to the toxicity of NMP, it has recently been replaced with lactate esters for cleaning. This is the application in integrated circuits. Therefore, photoresist is generally provided, and cleaning solution is also provided. Therefore, it is a combination of products to replace the photoresist and the cleaning solution of the photoresist with ethyl lactate.

Besides integrated circuits, there is also a display industry, the LCD industry, which mainly pours liquid crystals into the middle of two glass plates, and then encapsulates them with encapsulant. After encapsulation, it needs to be trimmed and cleaned. It also needs to be cleaned with lactate. Previously, NMP was used, but now lactate is used instead. Its main benefit is also that NMP is toxic and pollutes the environment. Ethyl Lactate is non-toxic to the human body and harmless to the environment.

2. Lactate ester’s cleaning and recovery process can basically recover about 90% through the rectification of the recovered liquid, and supplement 10% of the cleaning loss. The process of rectification and purification only costs about $0.4/kg, and the whole recovery is cost-effective. . In this way, it can be supplied to the cleaning plant for low price, and it can be taken back for recycling and re-evaporation, which not only solves the customer’s environmental protection problem, but also reduces the production cost. It is a very good solution for long-term recycling.