Method for preparing protective film playing a role in protecting glass micro-fluidic chips in etching process

Abstract

The invention relates to a method for preparing protective film playing a role in protecting glass micro-fluidic chips in etching process. The method comprises the steps of plating a glass substrate with a chromium sacrificial layer, smearing glue, baking the glue, performing UV exposure, developing, removing the chromium sacrificial layer, performing wet etching, removing the glue, removing the chromium sacrificial layer and sealing at high temperature when a glass micro-fluidic chip is conventionally manufactured. The method is characterized in that positive photoresist containing linear phenolic resin is taken as a basis; after the developing step and before the follow-up step of removing the chromium sacrificial layer, by taking a formaldehyde monomer aqueous solution or a glutaraldehyde aqueous solution with a certain concentration and pH value as a cross-linking agent, formaldehyde or glutaraldehyde and the linear phenolic resin in the positive photoresist containing the linear phenolic resin are subjected to cross-linking reaction; and the photoresist is cross-linked to be the protective film of which the body type is in a network structure so as to enable the photoresist protective film to prolong the time of tolerating the corrosion of hydrofluoric acid glass etching liquid and increase the etching depth of micro-fluidic channels. The method is applicable to the glass substrates plated with other metal sacrificial layers.

Description

technical field [0001] The invention relates to a protective film for etching glass microfluidic chips with high-depth channels or other glass microfluidic devices, in particular to etching glass microfluidic chips and other glass microfluidic devices. In the process of glass microfluidic devices, a method for preparing a protective film that protects glass microfluidic chips during etching is proposed by increasing the crosslinking degree of positive photoresist containing novolac resin. Background technique [0002] Glass has good electroosmotic properties and excellent optical properties. The background fluorescence generated during detection is much smaller than that of high molecular polymers. Its surface properties, such as wettability, surface adsorption and surface reactivity, are conducive to the use of different chemicals. The method is to modify its surface, and it is easy to form microchannels on the glass surface by hydrofluoric acid etching, and the microchanne...

AI Technical Summary

Problems solved by technology

However, it is difficult to obtain high-depth microchannels by using glass to make microfluidic chips, because the production of high-depth microchannels requires long-term etching of the glass surface, and the photoresist and chromium layers cannot withstand long-term hydrofluoric acid. Corrosion

Although some photoresists have slightly better performance, they cannot meet the requirements of deep etching, and these photoresists are expensive, which greatly increases the cost of making microfluidic chips

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