CN1530657A

CN1530657A - Preparation of plastic micro-flow control chip with screen pores

Info

Publication number: CN1530657A
Application number: CNA031111645A
Authority: CN
Inventors: 戴忠鹏; 罗勇; 盖宏伟; 林炳承
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2003-03-14
Filing date: 2003-03-14
Publication date: 2004-09-22
Anticipated expiration: 2023-03-14
Also published as: CN1242269C

Abstract

The preparing method incldues steps of template preparation and chip casting of which template preparation includes film covering, graph design, photolithgraphy and chemical etching. Its feature is that position for sieve pore to be formed on the template is designed as curve shape when design is carried on for graph.

Description

A kind of preparation method of the plastic microfluidic chip with sieve aperture

Technical field:

The present invention relates to chip production method, particularly with the preparation method of the plastic microfluidic chip of sieve aperture.

Background technology:

In the preparation of plastic microfluidic chip, extensively adopt casting, this method is, at first on silicon chip, use the wet (wet chemical etching method of carving, comprising galvanic corrosion and electrolytic corrosion) or do and carve (high-energy-rate etching, comprising the beam-plasma etching, plasma etching and laser ablation) method makes needed pattern masterplate, it is inlayed in the mould, in mould, pour into PDMS again, after waiting to solidify, take out, stamp storage liquid hole in the end place to the greatest extent at passage, last sealing-in is made desired chip on glass or PMMA plate.Because wet etching has advantages such as cost is low, and equipment is simple, and is easy to make, and the etching quality is good, so adopt this technology usually.But chip for some specific (special) requirements, have thin neck or be called the manufacturing process of the microflow hole chip masterplate of sieve aperture (1) can be comparatively complicated as somewhere at passage, normally, the conventional wet carving technology flow process that has the micro-fluidic chip masterplate of sieve aperture is: make the silicon chip of straight channel figure earlier, repeat wet-etching technique again and make the sieve aperture part on above-mentioned silicon chip.This technological process complexity, length consuming time.In addition; silicon crystal is that silicon atom relies on covalent bonds to form; each silicon atom and four atom covalence combinations on every side; form a positive tetrahedron in space distribution; this special construction of silicon crystal has determined that it is anisotropic when etching; promptly etching speed is big on specific direction; etching does not take place in other direction; thereby make that the projection at passage place is the trapezoid cross section after the etching; the vertical plane that is erosional surface (4) and protective surface (3) forms angle (Fig. 2); the existence of this angle causes can't carving the required thin-walled of sieve aperture of cast small-bore when the dark main channel of etching; if the etching face width of protecting on the silicon chip is 1 μ m; when the etching height is 20 μ m, then after the etching bottom surface wide be 30 μ m (Fig. 3), promptly can't carve cast 10 μ m following small-bore sieve aperture required thin-walled.

Summary of the invention:

The invention provides a kind of preparation method of the plastic microfluidic chip with sieve aperture, comprise masterplate preparation, chip cast step, wherein the masterplate preparation comprises overlay film, graphic designs, photoetching, chemical etching, when it is characterized in that graphic designs, the Position Design of masterplate sieve aperture to be generated is become curve shape.

Among the preparation method of the plastic microfluidic chip of band sieve aperture of the present invention, described curve can be one section circular arc, preferably the circular arc of 1/4 circle.

Monocrystalline silicon has anisotropic characteristics in chemical etching; its etching orientation is closely related with the crystalline orientation of wafer; also relevant with some interplanar alignment angle with masking graphics; have only when masking graphics and crystal face position line are perpendicular or parallel and just can make clear-cut; the very uniform trapezoidal channel of sidewall; otherwise,, then have the collapse phenomenon on limit of protective surface if when certain drift angle is arranged.Promptly can't protect fully when at the etching curvilinear figure, along with the variation of etching depth, the protective seam part comes off gradually, causes protecting the silicon of part to be etched away.The present invention utilizes this characteristic of monocrystalline silicon just, in passage, to do one section curve of sieve aperture place design and (be called curved channel down, as Fig. 4), in etching, control etching speed and time, thereby can etch thin-walled (2) (see figure 5) of needed small sectional area.Thin-walled (2) during the cast chip on the relative silicon chip just forms " sieve aperture ".

The preparation method of the plastic microfluidic chip of band sieve aperture provided by the invention, yield rate height, silicon wafer to manufacture save time, laborsaving.

Description of drawings:

The plastic microfluidic chip of Fig. 1 band sieve aperture;

Fig. 2 wet etching etching straight line on silicon chip forms the sectional drawing of angle;

Pour into a mould the sectional view of sieve aperture on Fig. 3 silicon chip with the thin-walled place;

The design drawing of Fig. 4 silicon chip upper curve passage;

Figure as a result after Fig. 5 silicon chip upper curve passage etching.

Embodiment:

The technological process of embodiment is as follows:

1) design on silicon chip earlier, be coated with dioxide/silica gel protection, photoetching, cleaning photoetching glue obtains the figure of desired band circular arc passage;

2) have under the situation of circular arc passage figure in protection, will protect the outer silicon dioxide layer of protection of figure to carve;

3) the outer monocrystalline silicon of etching protective seam makes circular arc passage place form the desired thin-walled of system sieve aperture, and speed of etching is that the time of etching is;

4) masterplate of making is inlayed in the mould, in mould, poured into PDMS, solidify the back taking-up and get final product.

The technological process of Comparative Examples is as follows:

1) design on silicon chip earlier, be coated with the dioxide/silica gel protection, photoetching, cleaning photoetching glue obtains the figure of desired band straight channel;

2) have under the situation of straight channel figure in protection, will protect the outer silicon dioxide layer of protection of figure to carve;

3) the exposed outward monocrystalline silicon of etched channels reach a certain height the protruding wall of system passage;

4) whole silicon wafer dioxide/silica gel protection for the second time;

5) repeating step 1), 2) operating process, make exposure process only in passage, need sieve aperture partly to carry out;

6) the protruding wall part that will make sieve aperture is etched into desired height;

7). the masterplate of making is inlayed in the mould, in mould, poured into PDMS, solidify the back taking-up and get final product.

Claims

1. preparation method with the plastic microfluidic chip of sieve aperture, comprise masterplate preparation, chip cast step, wherein masterplate preparation comprises overlay film, graphic designs, photoetching, chemical etching, when it is characterized in that graphic designs, the Position Design of masterplate sieve aperture to be generated is become curve shape.

2. according to the preparation method of the plastic microfluidic chip of the described band sieve aperture of claim 1, it is characterized in that described curve is one section circular arc.

3. according to the preparation method of the plastic microfluidic chip of the described band sieve aperture of claim 1, it is characterized in that curve is the circular arc of 1/4 circle.