SITE-SPECIFIC CONNECTING OF GLASS SUBSTRATES

Abstract

The invention relates to a process for connecting glass substrates which allows glass substrates to be aligned in a site-specific manner and to subsequently be connected to one another, and to the site-specifically aligned and interconnected glass substrates. Generally, the process relates to connecting glass substrates to one another, optionally also without site-specific alignment. The interconnected glass substrates obtainable by processes according to the invention are characterized by a firm bond with one another, which is preferably formed by solidified glass solder that is in form-fitting engagement with the glass substrates. Therein, recesses, which are preformed in the glass substrate, with glass solder are used for aligning and optionally for connecting the glass substrates.

Claims

1. A process comprising steps of: providing at least one glass substrate having spaced traversing and V-shaped tapered recesses each having a larger cross-section at a surface of the glass substrate and a smallest cross section opposite the larger cross-section, applying glass solder onto the surface of the glass substrate in which the recesses have their larger cross-section, heating the glass substrate with the glass solder applied thereto, and subsequently cooling the glass substrate with the glass solder applied thereto,

2. The process according to claim 1, wherein the cooling creates solidified glass solder that protrudes beyond the surface of the glass substrate adjacent to an area of smallest cross-section of the recess, the method comprising arranging another glass substrate with recesses matching over the solidified glass solder, subsequently heating to the melting temperature of the glass solder and subsequent cooling whereby the glass solder extends with form-fit through at least the areas of smallest cross-section of the matchingly arranged recesses of the glass substrates.

3. The process according to claim 1, comprising arranging at least two glass substrates with their recesses matching one another, so that their areas of smallest cross-section face one another, wherein glass solder is applied onto the surface of at least one glass substrate, in which surface the recesses have their larger cross-section, and subsequently the glass substrates are heated and subsequently cooled.

4. The process according to claim 1, comprising removing glass solder outside the recesses from the surface of the glass substrate prior to heating the glass substrate.

5. The process according to claim 1, wherein the recesses are arranged with the area of their smallest cross-section below their larger cross-section during the heating.

6. The process according to claim 1, wherein the traversing recesses are connected to channels that are formed blind-hole-shaped with a V-shaped cross-section in the surface of the glass substrate in which the larger cross-sections of the traversing recesses are arranged.

7. The process according to claim 1, wherein the glass substrate has blind-hole-shaped recesses with a V-shaped cross-section which form channels in the surface of the glass substrate and which are spaced from the V-shaped tapered recesses.

8. the process according to claim 1, comprising arranging another glass substrate having recesses in the form of blind holes on the surface of the glass substrate opposite the surface to which glass solder is applied, wherein the recesses of the glass substrates at least for a fraction overlap.

9. The process according to claim 1, wherein the substrate is arranged in a recess which is formed in a blind hold of another glass substrate, wherein the blind hold comprises an undercut into which glass solder flows during the heating.

10. A process for producing glass of porous structure in a glass substrate, comprising providing a glass substrate having traversing recesses with a V-shaped cross-section as an undercut, introducing glass solder glass frit into the recesses and subsequently heating the glass substrate with the glass frit.

11. The process according to claim 10, wherein the glass frit which comprises at least two glass types with different melting temperatures, and the heating is conducted only to the melting temperature of the glass type with the lower melting temperature.

12. The process according to claim 10, comprising introducing a mass containing or consisting of metal and/or ceramic into the recesses.

13. The process according to claim 12, comprising removing solidified glass solder after the introducing of a mass.

14. An assembly, comprising at least two glass substrates, a recess in at least one of the two glass substrates, the recess having an undercut that extends from the surface of the glass substrate, adjacent to which surface another one of the at least two glass substrates is arranged, wherein between the at least two glass substrates solidified glass solder is arranged which extends along and into the recess.

15. An assembly comprising at least two glass substrates, traversing recesses having smallest cross-sections in the area of one surface of one of the at least two glass substrates, and in the area of the smallest cross-sections of the recesses solidified glass older is arranged which protrudes beyond the surface of the glass substrate only in the area of the recesses, and another one of the at least two glass substrates is aligned with its recesses matching over the solidified glass solder, which protrudes over the surface of the one of the at least two glass substrates, and abuts against it.

16. The assembly according claim 15, wherein the solidified glass solder extends through matchingly aligned recesses of the abutting glass substrates, wherein the recesses, each with their areas of smallest cross-sections, face one another.

17. The assembly according to claim 15, wherein the at least two glass substrates comprise a first glass substrate that has a recess in the form of a blind hole in which a second glass substrate is arranged, which has at least one traversing recess having at least one undercut which is formed by the area of smallest cross-section of the traversing recess lying in the surface of the second glass substrate, which surface faces the first glass substrate, wherein solidified glass solder is arranged between the first and second glass substrates and the glass solder extends into the recess of the second glass substrate.

18. The assembly according to claim 17, wherein the recess of the first glass substrate has an undercut into which the solidified glass solder extends.

19. The assembly according to claim 17, wherein between the opposing surfaces of the glass substrate the recesses have V-shaped cross-section which has irregular, convex or rectilinear inner surfaces.

20. The assembly according to claim 17, wherein the recesses extend in a channel-like manner along the glass substrate.

21. The assembly according to claim 20, wherein least one glass substrate has a number of at least 2 recesses which have a cross-section, measured in the surface of the glass substrate, in the range from 10 μm to 1 mm.

22. (canceled)

23. (canceled)

Description

[0039] The figures show in

[0040] FIG. 1 A) to D) schematically an embodiment,

[0041] FIG. 2 A) to E) schematically an embodiment,

[0042] FIG. 3 A) to D) schematically a further embodiment,

[0043] FIG. 4 A) to D) schematically a further embodiment,

[0044] FIG. 5 A) to D) schematically a further embodiment,

[0045] FIG. 6 an electron micrograph of an embodiment, and

[0046] FIG. 7 schematically a preferred process for producing glass substrates with recesses.

[0047] FIG. 1 in A) shows a glass substrate 2 having a V-shaped recess 1, into which in B) glass frit paste 3 is introduced as glass solder, e.g. by a printing process or doctoring. The glass frit paste 3 is melted by heating and, after cooling, forms solidified glass solder 4 which protrudes beyond the plane of the glass substrate 2 in the area of the small cross-section of the recess 1 (FIG. 1C). A second glass substrate 5 can be arranged with its recesses 6 matching over the glass solder 4 which from the recesses 1 protrudes over the first glass substrate 2.

[0048] FIG. 2 in A) shows a glass substrate 2 having a V-shaped recess 1, into which in B) glass frit paste 3 is introduced, which is melted by heating in the furnace to its melting temperature, which is below the softening temperature of the glass substrate 2, and is subsequently cooled to solidified glass solder 4, which from the recess protrudes over the plane of the glass substrate 2, as shown in FIG. 2 C). After arranging a second glass substrate 5 matchingly with its recesses 6 over the solidified glass solder 4 (FIG. 2D), by renewed heating, e.g. in the furnace, a connection of the glass substrates 2, 5 can be created consisting of the solidified glass solder 4 extending into the matchingly aligned recesses 1, 6 of the two glass substrates 2, 5 (FIG. 2E). Therein, the recesses 1, 6 of the glass substrates 2, 5 are arranged with their surfaces adjacent to one another, in each of which the areas of the smallest cross-sections of their recesses are located.

[0049] FIG. 3 shows connecting of a first glass substrate 7 shown in FIG. 3A to a second glass substrate 2 having traversing recesses 1, each with an undercut within it. The first glass substrate has recesses 1 which traverse through its thickness or which extend only for a portion into the thickness of the glass substrate 7, forming blind holes. As shown in FIG. 3 A), the recesses 1 of the first glass substrate 7 are preferably aligned to match the recesses 1 of the second glass substrate 2, so that the recesses 1 of both glass substrates 2, 7 at least for a fraction overlap. FIG. 3 in the first glass substrate 7 shows a recess 1 which is formed trench-shaped, does not traverse completely through the first glass substrate 7, and extends in parallel to the plane of representation, while the recesses I of the second glass substrate with undercut are formed conically round or elongated as elongated holes, which e.g. are arranged in perpendicular to the recesses 1 of the first glass substrate 7. The second glass substrate 2 has traversing recesses, each of which is V-shaped and faces the first glass substrate 7 with its smaller cross-sectional opening.

[0050] Glass solder in the form of glass frit 3 is applied (FIG. 3B) onto the surface of the second glass substrate 2 that lies opposite to the first glass substrate 7. Thereby, the glass solder is applied into the larger cross-sections of the recesses, which are preferably line-shaped. Subsequent melting of the glass solder (FIG. 3C), e.g. by heating in a furnace, leads to the distribution of the molten glass solder through the recesses 1, which traverse through the thickness of the second glass substrate 2, and into the interspace between the first glass substrate 7 and the second glass substrate 2, optionally onto the surface of the second glass substrate 2 that lies opposite to the first glass substrate 7. The cooling results in solidification of the glass solder 4 (FIG. 3D) and in the form-fitting connection of the recesses of the second glass substrate 2 to the first glass substrate 7.

[0051] Alternatively or additionally, the first glass substrate 7 can have a blind-hole-like recess in which a second glass substrate 2 is arranged at least sectionally. Therein, the first glass substrate 7 preferably has a blind hole with an undercut 8 into which solidified glass solder 4 can extend.

[0052] The second 21 has substrate 2 has traversing recesses, each of which is V-shaped and with its smaller cross-sectional opening faces the first glass substrate 7. Glass solder in the form of glass frit 3 is applied (FIG. 3B) onto the surface of the second glass substrate 2 that lies opposite to the first glass substrate 7. Thereby, the glass solder is applied into the larger cross-sections of the recesses, which are preferably line-shaped. Subsequent melting of the glass solder (FIG. 3C), e.g. by heating in a furnace, results in the distribution of the molten glass solder through the recesses 1 traversing through the thickness of the second glass substrate 2 and into the interspace between the first glass substrate 7 and the second glass substrate 2, optionally onto the surface of the second glass substrate 2 that lies opposite to the first glass substrate 7. The cooling leads to the solidification of the glass solder 4 (FIG. 3D) and to the form-fitting connection of the recesses of the second glass substrate 2 with the first glass substrate 7.

[0053] FIG. 4A) shows the assembly of two glass substrates 2, each having traversing V-shaped recesses 1, above a glass substrate 7 having V-shaped recesses 1. The recesses 1 of the glass substrates 2, 7 overlap at least partially, The recesses of the glass substrates 2 with their smaller cross sections each face the glass substrate 7 lying below, so that the V-shaped recesses 1 of the glass substrates 2 lying above form undercuts for solidified glass solder. The recesses 1 in the glass substrate 7 lying below can traverse through it or, as shown, be in the form of long holes or resp. blind holes which run in perpendicular to the recesses 1 arranged in the glass substrates 2 lying above. FIG. 4B) shows the application of glass solder in the form of glass frit 3 onto the surface of the upper glass substrate 2. The melting of the glass solder 4 (FIG. 4C) leads to its distribution in the recesses I of the two second glass substrates 2 and between the lower one of the second glass substrates 2 and recesses in the first glass substrate 7, optionally including its undercut 8. The form-fitting and preferably material-fitting connection in the assembly of two glass substrates 2 with a further glass substrate 7 with solidified glass solder 4 arranged in between, which glass solder 4 extends through the recesses 1 of the second glass substrates 2, is shown in FIG. 4D).

[0054] Alternatively, the recess formed in the glass substrate 7 can have the form of a blind hole which preferably has an undercut 8 into which glass solder 4 can flow and solidify therein. Therein the glass substrates 2 can be arranged in this blind hole and can he form-fittingly connected to the glass substrate 7, in which the blind hole is formed, by solidified glass solder 4 extending through their recesses 1 and into the recess of the blind hole.

[0055] FIG. 5A) shows a process of connecting a glass substrate 2 which has a recess 1 in the form of a V-shaped trench along its peripheral edge. Therein, the recess 1 can be traversing or can extend only for a fraction of the thickness of the glass substrate 2. After applying glass solder 3 within the surface area of the glass substrate 2 encompassed by the trench, e.g. by printing next to and/or into the recess 1 (FIG. 5B), a further glass substrate 7, which optionally has traversing recesses with undercuts or has an uninterrupted surface, is loaded against the glass substrate 2 so that the glass solder 3 is distributed between the glass substrates 2, 7 and in the direction of the peripheral edge is stopped in spreading by the V-shaped trench (FIG. 5B). By melting the glass solder 3 and subsequent cooling, solidified glass solder 4 is formed between the glass substrates 2, 7 (FIG. 5C), which glass solder preferably extends into recesses of at least one, optionally of both glass substrates 2, 7. Thereby, the solidified glass solder 4 connects the glass substrates 2, 7 in a form-fitting and preferably force-fitting manner (FIG. 5D).

[0056] FIG. 6 shows an electron micrograph of a longitudinal section along a frustoconical recess traversing through a glass substrate, wherein in the recess a solidified mixture of a glass frit with 5% low-melting glass type and 95% higher-melting glass type forms a porous structure that fills the recess. The glass substrate was heated to the melting temperature of the low-melting glass type of the frit.

[0057] FIG. 7 A) in sectional view shows a process for generating recesses 1 in a glass substrate 2 by irradiating an original glass substrate 2a with laser radiation L at the locations where recesses 1 are to be generated. The laser beam L, which is generally preferably a sequence of laser pulses, penetrates the glass substrate 2a up to a depth dependent on the focal position and generates a modification M therein. FIG. 7 B) in sectional view illustrates that the subsequent etching of the glass substrate 2a generates the recesses 1 in the glass substrate 2. In particular by irradiating the laser beam L up to a small distance in front of or as far as through the opposite surface of the glass substrate 2, a traversing recess is created during the subsequent etching.

[0058] FIG. 7 C) and D) in the top view onto the glass substrate 2 illustrate that along the line-shaped modification M, e.g. from laser radiation formed by laser pulses irradiated side by side, during the subsequent etching microstructures in the form of trench-shaped recesses 1 are produced. Trench-shaped recesses can also be formed traversing through the thickness of the glass substrate 2.

[0059] FIGS. 7 E) to G) show an alternative process generating recesses 1, in which process an original glass substrate 2a is penetrated by laser radiation L through the cross-section of the glass substrate 2a to generate a modification M extending through the cross-section of the glass substrate 2. A surface of the glass substrate 2 is coated with etch resist R, e.g. lacquer or plastic film. During subsequent etching, the glass substrate 2 is not affected on the surface coated by etch resist R, so that the generated recess 1 extends into the glass substrate 2 from the surface that lies opposite to the etch resist R. Subsequently, the etch resist R is preferably removed.