DE102016204228A1 - Dispensing device for glass dispensing - Google Patents

Abstract

Disclosed is a dispensing device with which molten glass can be brought onto a substrate. For this purpose, a nozzle is provided, from which the molten glass can escape. For wetting the substrate, the nozzle can be moved to the substrate and then moved away again.

Description

The invention is based on a dispensing device with which a glass, for example as an adhesive, can be applied to a substrate. Moreover, the invention relates to a method for dispensing glass with the dispensing device.

In lighting applications, a composite of two or more components is often required, with a connection point being transparent on the one hand and permanently temperature-resistant on the other. Especially in the field of solid state lighting, the joints are in some cases significantly relevant to a function, a lifetime and an efficiency of the entire system. Typically, such a composite is realized with temperature-resistant adhesives, such as silicones. These are in particular temperature resistant up to about 160 ° C. Another possibility is the use of glass solders which are applied in paste form, for example via a dispensing device, and then debinded.

Thus, with a known dispensing device, a paste of glass powder can be applied to a substrate. With the paste, a component, in particular a conversion element for wavelength conversion of laser light for the LARP (Laser Activated Remote Phosphor) technology, can be bonded to the substrate. The disadvantage here is that a glass powder is required for the paste, whereby upon heating atmosphere between the particles is included. Usually, the paste has a binder and solvent, and therefore, a drying step and a debinding step must be performed before the glass powder softens. The preparation of the glass powder and the paste is time consuming and costly. Through the grinding process in the production of the glass powder impurities can be introduced.

The object of the present invention is to provide a Glasdispensierungsvorrichtung, which is simple in design, and can be done with a low-cost glass dispensing with a high quality. Furthermore, it is an object of the invention to provide a cost-effective method for Glasdispensierung.

This object is achieved with regard to the glass dispensing device according to the features of claim 1, with respect to the substrate according to the features of claim 8 and with regard to the method according to the features of claim 9.

Particularly advantageous embodiments can be found in the dependent claims.

According to the invention, a dispensing device is provided with a crucible or with a container for producing melts or with a storage cavity or with a metering crucible. The crucible serves to receive a glass melt or to melt glass mixtures or to melt glass, e.g. in the form of broken glass, glass melt, breakage, frit, moldings, e.g. Balls, fiber sections, gobs. The use of glass powder is also possible, but not the preferred embodiment. Through a channel, the crucible can be opened to the outside to apply molten glass to a substrate. The channel preferably opens in an outer dispensing area. This can point downwards as seen in the vertical direction. Molten glass can then, in particular as a glass drop, be applied via the channel and / or via the dispensing surface to a substrate, in particular arranged below the dispensing surface. Advantageously, the dispensing surface and / or the substrate is displaceable in the vertical direction.

This solution has the advantage that, with such a dispensing device, it is possible to use glass in previously mentioned forms as a dispensing material in a manner that is simple in terms of the apparatus. The actual dispensing can then be done simply by wetting the substrate with the molten glass (lens contact) and / or by contacting the dispensing surface (dispensing nozzle) and then lifting the dispensing surface.

Advantageously, in addition to the crucible and the substrate, in particular independently of the crucible, heatable, whereby a permanent connection of the glass with the substrate is made possible and the dispensing process is better controlled. The latter also includes a process control with regard to the crystallization behavior of the glass. In a further embodiment of the invention, a displacement speed of the dispensing surface and / or the substrate, in particular in dependence on the displacement, adjustable. The displacement speed has an influence on the design of the molten glass applied to the substrate, which makes it possible to influence the design of the adhesive joint in a simple manner.

Advantageously, the temperature of the crucible and / or the substrate can be adjusted / regulated.

By the displacement speed and / or by a lift-off speed and / or by a temperature control of the crucible and / or the substrate and / or the nozzle geometry, the metered amount can be regulated.

Preferably, the channel is part of a nozzle. The channel can be designed as a dispensing bore or bore. It has been shown that the channel can have an approximately constant cross-section, which is extremely simple in terms of device technology. The channel preferably extends in whole or in sections, or at least with its opening in the dispensing surface portion approximately in a vertical direction. It has proven to be advantageous if a diameter of the channel is greater than or equal to 0.05 mm and less than or equal to 0.5 mm, in particular if this has an approximately circular cross-section. Alternatively, in particular in the case of a circular cross section or in the case of a cross section deviating from the circular shape, for example a polygonal or rectangular shape, a cross sectional area of the channel may be between 0.01 mm ² and 5 mm ² , preferably between 0.02 mm ² and 0.2 mm ² amount. In this case, the glass is transported, in particular by the acting capillary forces, from the storage crucible to the dispensing surface.

Preferably, the dispensing surface is part of the nozzle. In order for the molten glass to form approximately in a lens mold at the dispensing surface through adhesion forces and cohesive forces, the dispensing surface is preferably approximately planar and / or extends in a horizontal direction and / or is approximately circular or angular or approximately rectangular. So that the molten glass accumulating on the dispensing surface does not expand at will, the dispensing surface is delimited by an outer edge. On the outer edge can then be limited, in particular maximum horizontal adhesive forces based propagation of a glass drop. Preferably, the Dispensierungsfläche a size between 0.02 mm ² and 10mm ^2, preferably between 0.04 mm ² and 3 mm ^2. The dispensing surface preferably has a diameter of greater than or equal to 0.1 mm and less than or equal to 1 mm, in particular if it is approximately circular.

In other words, the crucible (nozzle) has a glass exit end at which there is a small ledge with a flat surface. This surface is wetted by adhesion forces with the liquid glass, with a boundary being the outer edge of the projection. Cohesive forces form a lens. The shape of this lens is dependent on a surface tension of a nozzle material and the glass, a nozzle geometry and a viscosity of the glass.

Preferably, the nozzle tapers conically in a direction away from the crucible, wherein it has the dispensing surface at its end, that is to say with its end section facing away from the crucible.

Optionally, the molten glass, in particular crucible side, with an additional pressure, so in addition to the atmospheric pressure, acted upon.

In a further embodiment of the invention, at least a portion of contact surfaces or all contact surfaces of the crucible and / or the nozzle, which are brought into contact with the molten glass, a surface which does not react with the molten glass. Alternatively or additionally, it can be provided that the crucible and / or the nozzle at least partially consists of a material which does not react with the molten glass. In particular, the crucible and / or the nozzle has as material a metal or a ceramic or a glass or a glass ceramic. It is also conceivable that the crucible and / or the nozzle have as material a noble metal or a noble metal alloy, which advantageously additionally have good heat conduction and are poorly wettable by glass.

In other words, the metering cup with the nozzle is made of a suitable material that does not react with the glass melt.

According to the invention, a substrate is provided, which is preferably used for the dispensing device according to one or more of the preceding aspects. The substrate here preferably consists at least substantially or completely of a metal and / or a ceramic and / or a glass and / or a glass ceramic.

Furthermore, it is conceivable that the substrate has layers or layer stacks. It is conceivable that one or more or all of the layers have at least one function. It is conceivable, for example, that a filtering and / or passivating and / or protective and / or reflective function or effect is provided as a function. If the substrate has a layer structure, it is advantageous if a top layer or outer layer of the substrate is wetted with the molten glass. The finishing layer or outer layer then preferably comprises an oxidic material.

It is also conceivable that the substrate is an optoelectronic component.

Advantageously, the dispensing surface and the substrate or the layer to be wetted of the substrate are arranged approximately at a parallel distance or plane-parallel to one another. In other words, the glass lens at the nozzle is contacted, for example, with the end layer of the substrate such that the Nozzle exit surface is preferably aligned plane-parallel to the substrate.

• – Befüllen des Tiegels mit Glas in vorher genannten Formen,
• – Erhitzen des Tiegels und/oder Düse zum Schmelzen des Glases,
• – Optional Beheizen des Substrats,
• – Dispensierungsfläche zum Substrat führen bis das geschmolzene Glas und/oder die Dispensierungsfläche das Substrat mechanisch kontaktiert. Alternativ oder zusätzlich kann das Substrat zur Dispensierungsfläche geführt werden, bis das geschmolzene Glas und/oder die Dispensierungsfläche das Substrat mechanisch kontaktiert.
• – Wegbewegen der Dispensierungsfläche vom Substrat und/oder Wegbewegen des Substrats von der Dispensierungsfläche, insbesondere mit einer kontrollierten und/oder gesteuerten Geschwindigkeit.

In a method according to the invention for dispensing molten glass with a dispensing device, in particular according to one or more of the preceding aspects, the following steps are provided:

• Filling the crucible with glass in previously mentioned forms,
• Heating the crucible and / or nozzle to melt the glass,
• Optionally heating the substrate,
• - Dispensierungsfläche lead to the substrate until the molten glass and / or the dispensing surface mechanically contacts the substrate. Alternatively or additionally, the substrate can be guided to the dispensing surface until the molten glass and / or the dispensing surface mechanically contacts the substrate.
• Moving the dispensing surface away from the substrate and / or moving the substrate away from the dispensing surface, in particular at a controlled and / or controlled speed.

With the method according to the invention it is not intended to use a paste of glass powder, as in the prior art. As a result, the molten glass has fewer pores at a comparable working temperature. There is neither a debinding step nor a drying step required by the use of glass melt, which fewer process steps are provided compared to the prior art, since the glass can be processed directly from the melt. A production of the glass powder and the paste are also eliminated. In addition, impurities from the grinding process for the glass powder and variations in the properties of the paste and the glass powder can not occur. A specification of this is completely eliminated. Thus, the method according to the invention is a cost-effective process with fewer process steps compared to the prior art, which also reduces quality fluctuations caused thereby. In addition, fewer test steps are required due to the smaller number of process steps.

In other words, a composite of different components can be realized by the use of a molten glass, preferably low melting. The glass is held in a high-temperature metering system or the dispensing device at a temperature at which it is in a low-viscosity state. This liquid glass is then applied directly in the desired form and amount to the preheated composite partners.

The glass is preferably heated up to a certain specific glass temperature at a viscosity of between less than or equal to 10 ^7.6 dPa · s and greater than or equal to 10 ⁰ dPa.s present ⁽⁰ 10 dPa · s ≤ viscosity ≤ 10 ^7.6 dPa.s). In particular, the viscosity is less than or equal to 10 ⁴ dPa · s and greater than or equal to 10 ¹ dPa · s (10 ¹ dPa · s ≦ viscosity ≦ 10 ⁴ dPa · s). Preferably, the temperature is selected such that the glass does not crystallize during the processing time and does not vaporize glass components. Furthermore, the heating of the glass can take place in such a way that the crystallization and nucleation region of the glass is passed through as quickly as possible. For example, the glass has a softening temperature between 250 ° C to 450 ° C, preferably between about 300 ° C and 350 ° C. The glass or glass shards may then be heated in the crucible to a temperature of between 400 ° C to 800 ° C, preferably between 500 ° C to 700 ° C.

In addition to the crucible, the substrate is preferably heated or heated. This is preferably done before or while the dispensing surface is guided to the substrate. Advantageously, a temperature in this case is between 150 ° C and 700 ° C, for example mentioned above, preferably between 250 ° C and 550 ° C, ideally between 300 ° C and 450 ° C. This depends on the temperature resistance of the substrate.

A speed at which the dispensing surface and the substrate are moved away from each other or in which the dispensing surface is moved away from the substrate or in which the substrate is moved away from the dispensing surface is for example between 0.05 mm / s and 100 mm / s , preferably between 0.1 mm / s and 5 mm / s.

For example, the glass gob formed on the substrate is in a volume range of 0.0005 to 0.05 mm ³ .

Preferably, the molten glass or glass drop on the dispensing surface is low in bubbles and glassy. For special embodiments, it is also conceivable that the glass gob is partially or completely crystallized.

In the method, for example, a single glass drop is dispensed. This can then be used for bonding a, for example, circular conversion element to the substrate, as may be provided, for example, in the LARP technology with a static light source or laser light source. It is also conceivable that with the method several glass gobs are applied to the substrate, which are present separately or combine to form a surface can. These could be used for example for bonding a larger conversion element to the substrate, as may be provided for example in the LARP technology with a dynamic light source or laser light source. In addition, it is conceivable that with the method one or more lines of molten glass can be formed on the substrate. These can also be provided for bonding a larger conversion element to the substrate or, for example, also for an arrangement of hermetically sealed encapsulations. It is also conceivable that the method dispenses an area which, for example, can also be used for bonding a larger conversion element to the substrate. Also, with the method several layers can be dispensed one above the other. This is advantageous for increased layer thicknesses or even for transition glass combinations. Here, the individual layers may have different properties, for example to change a thermal expansion gradually between a lowermost layer and an uppermost layer. With several layers formed on top of each other, it is also conceivable to form complex three-dimensional structures. If necessary, a combination of the above-mentioned variants of Dispensierungsarten is conceivable. It is also conceivable to use and combine different glasses.

With the dispensing device according to the invention and the method according to the invention glass can be applied in a defined amount and form directly as glass melt on one or more composite partners. Pre-assembly of the glass is not required, whether as glass solder paste or in solid form. A debinding step, as with the use of printed glass solder pastes, is eliminated. The processing temperatures are lower compared to the glass solder paste, since no air bubbles must be expelled. By preheating the partners, process times can be shortened. When using a suitable glass, the compound is e.g. also long-term stable at temperatures greater than 200 ° C and thus also suitable for thermally stressed applications.

The Applicant reserves the right to make a claim to use of the substrate for the dispensing device according to one or more of the preceding aspects. Furthermore, Applicant reserves the right to claim the use of broken glass for a dispensing device according to one or more of the preceding aspects.

In the following, the invention will be explained in more detail with reference to an embodiment. The figures show:

1 in a perspective view of a dispensing device according to an embodiment

2a to 2d each in a schematic representation of a method step of a method with the dispensing device according to the embodiment

According to 1 has a dispensing device 1 a crucible 2 , Which has a larger storage cavity, in the glass in the aforementioned form, for example, as a piece of glass can be arranged. The crucible 2 has a heating element, which is operated for example with 150 watts and, for example, can heat the glass to 600 ° C. Outwardly, the heating element is preferably insulated. The crucible 2 is down, seen in vertical direction, via a nozzle 4 open. Through this molten glass can emerge and be applied to a substrate. The crucible is attached 2 in an L-shaped retaining element 6 , which is composed of two retaining plates. An approximately horizontally extending holding leg 8th (first holding plate) of the holding element 6 is then over thermal insulation elements 10 with the crucible 2 connected. Another holding leg 12 (second holding plate) extends approximately in the vertical direction. This is on a drive unit 14 attached, which has a servomotor. About the drive unit 14 is the crucible 2 along with its nozzle 4 in vertical direction 16 movable. Furthermore, on the holding leg 8th a device 18 intended for a crucible change.

Furthermore, it is provided that the retaining element 6 displaceable in the vertical direction as a carriage on the drive unit 14 is attached, which is designed here as a rail. According to 1 is the retaining element 6 in this case at a lower stop of the drive unit 14 arranged by gravity. Get the retaining element 6 over the nozzle 4 at a shift in the vertical direction by the drive unit 14 in contact with the substrate, so may the drive unit 14 relative to the holding element 6 move further in the vertical direction (lowering direction), without the substrate of the driving force of the drive unit 14 is charged. The holding element 6 would then stand out together with the attached components from the lower stop. The substrate is thus at most with the weight of the retaining element 6 and applied to the components attached thereto. It would also be conceivable, for example, to provide a spring element in order to further relieve the substrate when the nozzle is arranged.

According to 2a is the nozzle 4 represented, which has an approximately frustoconical configuration. On its underside is an approximately circular dispensing surface 20 educated. In this opens a channel 22 , which is introduced as a bore, for example. The channel 22 flows in particular approximately in the middle of the dispensing area 20 , The channel 22 extends approximately perpendicular to the dispensing surface 20 and is with the storage cavity of the crucible 2 out 1 connected. The nozzle 4 is either over the crucible 2 heated or heated separately. Below the nozzle 4 is a substrate 24 arranged on the one about lenticular glass melt 26 is applied by the method, which is located on the dispensing surface 20 collects. An upper outer layer or top 28 of the substrate 24 points to the dispensing area 20 and extends approximately at a parallel distance to this. The substrate 24 is also heated.

According to 2 B is used to apply the glass melt 26 the nozzle 4 via the drive unit 14 out 1 towards the substrate 24 vertically, in particular at a controlled speed. A travel is calculated so that the glass melt 26 the substrate 24 contacted mechanically.

According to 2c becomes the top 28 of the substrate 24 from the glass melt 26 wetted. The nozzle 4 is then via the drive unit 14 out 1 from the substrate 24 moved away. The movement takes place here with a controlled speed, which influences a quantity and an embodiment of the on the substrate 24 has remaining molten glass.

In 2d is shown a state in which the nozzle 4 so far from the substrate 24 moving away is that molten glass 26 and one on the substrate 24 remaining glass melt 30 are separated from each other. The remaining glass melt 30 then forms a dispensed glass volume on the substrate 24 ,

Disclosed is a dispensing device with which melted, in particular low-melting glass can be brought onto a substrate. For this purpose, a nozzle is provided, from which the molten glass can escape. For wetting the substrate, the nozzle can be moved to the substrate and subsequently moved away again, or the substrate can be moved away from the nozzle every now and then.

LIST OF REFERENCE NUMBERS

1

 Dispensierungsvorrichtung

2

 crucible

4

 jet

6

 retaining element

8th

 holding leg

10

 insulation element

12

 holding leg

14

 drive unit

16

 vertical direction

18

 Device for crucible change

20

 Dispensierungsfläche

22

 channel

24

 substratum

26

 molten glass

28

 top

30

 molten glass

Claims (13)

Dispensing device with a crucible ( 2 ) for melting glass mixtures or melting glass, which is transported via a channel ( 22 ) is opened to the outside, the channel ( 22 ) in an outer dispensing area ( 20 ), with molten glass passing over the channel ( 22 ) and / or the dispensing surface ( 20 ) on a substrate ( 24 ), the dispensing surface ( 20 ) and / or the substrate ( 24 ) is / are displaceable. Dispensing device according to claim 1, wherein the crucible ( 2 ) and the substrate ( 24 ) are heated. Dispensing device according to claim 1 or 2, wherein the displacement speed of the dispensing surface ( 20 ) and / or the substrate ( 24 ) is / are adjustable. Dispensing device according to one of the preceding claims, wherein the channel ( 22 ) and the dispensing area ( 20 ) a part of a nozzle ( 4 ) are. Dispensing device according to one of the preceding claims, wherein the channel ( 22 ) has a cross-sectional area between 0.01 mm ² and 5 mm ² , preferably between 0.02 mm ² and 0.2 mm ² . Dispensing device according to one of the preceding claims, wherein the dispensing surface ( 20 ) is approximately planar and / or extends approximately in the horizontal direction and / or is circular. Dispensing device according to one of the preceding claims, wherein the dispensing surface ( 20 ) an area between 0.02 mm ² and 10 mm ² , preferably between 0.04 mm ² and 3 mm ² . A substrate used for a dispensing device according to any one of the preceding claims, wherein the substrate ( 24 ) consists at least substantially or completely of metal and / or ceramic and / or glass and / or glass-ceramic, and / or wherein the substrate ( 24 ) has a plurality of layers. Method for dispensing molten glass with a dispensing device, in particular according to one of claims 1 to 7, comprising the steps of: - filling a crucible ( 2 ) with glass or low-melting glass or glass mixtures, - heating of the crucible ( 2 ) and / or a nozzle ( 4 ) for melting the glass, - dispensing surface ( 20 ) to the substrate ( 24 ) lead to the molten glass and / or the dispensing surface ( 20 ) the substrate ( 24 ) mechanically contacted, and / or substrate ( 24 ) to the dispensing area ( 20 ) lead to the molten glass and / or the dispensing surface ( 20 ) the substrate ( 24 ) mechanically contacted, - moving away the dispensing surface ( 20 ) from the substrate ( 24 ) and / or moving away the substrate ( 24 ) from the dispensing surface ( 20 ). The method of claim 9, wherein the glass or glass batch is heated to a specific glass specific temperature at which a viscosity is between less than or equal to 10 ^7,6 dPa · s and greater than or equal to 10 ⁰ dPa · s, or preferably one Viscosity is less than or equal to 10 ⁴ dPa · s and greater than or equal to 10 ¹ dPa · s. The method of claim 9 or 10, wherein the glass or glass batch is heated to about 400 ° to 800 ° C, and / or wherein the substrate ( 24 ) is heated to 150 ° to 700 ° C. Method according to one of claims 9 to 11, wherein a speed of the dispensing surface ( 20 ) is between 0.05 mm / s and 100mm / s when moving away. The method of any one of claims 9 to 12, wherein the glass or glass batch has a softening temperature between about 250 ° C and 450 ° C.

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