DE2541205A1 - PROCEDURE FOR ETCHING A PATTERN IN GLASS - Google Patents

Description

PHN 7737

JELM / JV / JB

8-9-1975 2541205

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_{MI =:} PHN-7737

A "me.dun _B νο.π. ^. Sept 1975

" Method for etching a pattern in glass "

The invention relates to and to a method of etching a pattern in glass manufactured egg products.

From U.S. Patent 3 ^ 8962 ^ is a

Such a method is known in which on the glass surface first a uniform tin oxide layer by means of a pyrolysable tin compound at elevated temperature and then a layer of a light-modifiable etch reserve lacquer is applied, and the latter layer is exposed and then developed so that a coating can be enjoyed the negative of a pattern desired in the glass fall back; r, vonach echliosslicli the exposed glass surface

609815/1 176 ORIGINAL BATHROOM

PHN 7737-2-8-9-1975

area exposed to a hydrofluoric acid Is exposed to etchant.

The tin oxide is attached by bringing the glass to a temperature between 400 ° C and the softening temperature The glass is heated and then a liquid or dissolved pyrolysable tin compound is injected onto it will. This tin oxide, which has a complex structure, where chemical bonding with the glass plays a role plays, secures the liability of the through as an intermediate layer Light-modifiable etch reservation layer on the glass surface. None of the usual photosensitive lacquers adheres to glass to a sufficient degree. There are positive and negative photoresists are available, i.e. resists that are soluble in a certain reagent and after 'exposure become insoluble, or varnishes that are insoluble in a certain reagent and after exposure dax "in soluble wex-den. The removal of the soluble parts of the paint in the appropriate solvent is called "development" designated.

After development is on the parts outside of the pattern to be etched, the glass over a tin oxide layer still with the exposed etch reservation layer overdrawn. The glass in the sample parts is coated with a tin oxide layer that must first be removed. To do this, the tin oxide is mixed with an acidic solution for some time

6 0 9 815/1176

PHN 7737-3- '"8-9-1975

kept in contact under strongly reducing conditions, e.g. an HCl solution with zinc powder in contact with the Tin oxide.

In practice it turns out that the

The adhesion of the etch reserve varnish to the tin oxide is not particularly good; the end result often leaves a lot to be desired.

The invention provides a method with which

a result of significantly higher quality is achieved. In addition, this method has a comparison with the one described above Procedure has a few more advantages.

The procedure for etching a pattern in glass,

in which a uniform metal oxide layer and then a layer of a light-modifiable etch reserve lacquer is applied to the glass surface first via a pyrolyzable metal compound at elevated temperature, then the latter layer is exposed and developed so that an etchant-resistant coating according to the negative of one in the glass desired pattern remains, after which the exposed glass surface is exposed to the action of an etching agent containing hydrofluoric acid, is characterized according to the invention in that the glass surface is brought into contact with a pyrolysable titanium compound at a temperature between 180 and 2hO ° C.

609815/1178

PHN 7737 8-9-1975

The titanium dioxide, · that therefore with a lot

lower temperature than the tin oxide is applied, has an amorphous structure and forms a very good Adhesive intermediate layer for the etching reserve varnish. the lower temperature is much more favorable in connection with deformation of the glass.

The titanium dioxide dissolves in the hydrogen fluoride acidic caustic is slow. Because the titanium dioxide layer only needs to be very thin (at most 0.1 / µm) and is also somewhat porous, it is removed relatively quickly. The solution speed difference but also has the consequence that undercutting is almost completely avoided. In any case, it falls into place the method according to the invention removes the additional treatment step that is required in the method using Tin oxide is required.

As a pyrolysable titanium compound that is used in the Process according to the invention can be used, organic titanium compounds such as titanium acetylacetonate or Isopropyl titanate. In order to obtain greater etching depths, it is advisable to first roughen the glass as described in DT-OS 2362896.

The etched product obtained by the method according to the invention can be used for many purposes

6098 15/1176

PHN 7737-5-8-9-1975

e.g. as a cliché for printing processes, as a mother plate for information recorded optically or as an anode plate for display panels.

The invention is explained in more detail below using a few exemplary embodiments. example 1

A lime glass plate is cleaned for 5 minutes by ultrasound treatment in a bath that:

1 liter H ₂ ^S0 k

35 nil saturated KpCr “O_ solution in HO

contains, and then rinsed in running water for 1 minute. The plate is then cleaned in isopropane oil vapor for 5 minutes. After cooling, the plate is made of a 5 wt. ^ Solution of txtanacetylacetonate in isopropanol drawn up at a speed of 2.5 cm / min. The plate is ^{dried at 220 °} C. for 10 minutes and then provided with a photoresist by mounting, which is commercially available as Shipley AZ. The photoresist is dried for 10 minutes at 70 ° C. and then exposed for 1 minute through a negative with a high pressure mercury vapor lamp (type HPR '125 W) at a distance of 30 cm. The exposed photoresist is dissolved (developed) with Shipley AZ developer (time datator 2 minutes), rinsed and dried. The glass plate, which is provided with photoresist in places, is then dried in an oven at 120 ^° C. for 5 minutes.

609815/1176

PHN 7737-6- '8-9-1975

The glass is now etched by dipping it into an aqueous HF solution. The etching depth is determined by the treatment time and the concentration of the HP solution. The etching speeds for the various concentrations are:

1 O $ HF 1.5 / µm / min

$ 20 HF 5 / um / mi

/ um / mxn

30 $ HF 10 / µm / min

kO io HF - 30 / um / min.

With this method it is possible to etch patterns with a depth of 20 µm. The undercut factor is 0.5 · The etch depths are measured with a Talysurf 10. In game II

If patterns with greater depth are to be etched , it is necessary that the photoresist adheres better to the glass. To this end, the method described in DT Offenlegungsschrift 2362896 is used. The lime glass is first roughened mechanically by mechanical grinding with silicon carbide powder (Sie) with a grain size of kh / µm (grain 2 ^ 0 according to FEPA standard) and then chemically treated with 10 ^ HF solution for 10 seconds, rinsed and dried. _{An amorphous TiO p} layer and a photoresist were then applied in the manner described in Example I. After this pre-treatment it is possible to create at least 200 µm deep patterns

609815/1178

PHN 7737 8-9-1975

25A1205

etching. The undercut factor remains 0.5 · Example III

A borosilicate glass plate is cleaned in the manner described in Example I and provided with an amorphous TiO _p layer and photoresist. When etching with 40 io HF, the depth as a function of time is as follows:

1 minute 12 / um

2 minutes 17 / um

3 minutes 21 / um.

In the case of a pretreatment according to Example I, the maximum etching depth is 8 μm, and in the case of a pretreatment according to Example II, the etching depth is again unlimited. The undercut factor is 0.5.
Example IV

A quartz plate is placed on the in Example I.

pretreated manner as described. When etching in ^ O 5 ° H ^ becomes get the following depth as a function of etching time:

1 minute h / um

2 minutes 6 / um

1 /

3 minutes . 8 / um.

In the case of a pretreatment according to Example I, the maximum etching depth is 3 μm and in the case of a pretreatment according to Example II the etching depth is unlimited. The undercut factor is 0 * 5.

609815/1176

Claims (2)

7737-8- '8-9-1975 PATENT CLAIMS: 1. method of etching a pattern in glass, the first on the glass surface via a pyrolyzable metal compound at elevated temperature a uniform metal oxide layer and then a layer of a light-modifiable etch reserve lacquer attached then the latter layer is exposed and developed so that an etchant-resistant coating is formed. according to the negative of a desired pattern in the glass remains, after which the exposed glass surface of the action is exposed to a hydrofluoric acid-containing etchant, characterized in that the glass surface at a temperature between 180 and 2 ^ 0 ° C with a pyrolyzable titanium compound is brought into contact. 2. The method according to claim 1, characterized in that the thickness of the titanium dioxide obtained is at most 0.1 / µm. . "3 · Glass product with a Mustex *, which by the Method according to claim 1 or 2 is etched. 6098 1 B / 1176