KR20050016343A - Holding-down device and transport system for flat products to be transported - Google Patents

Abstract

The present invention relates to a holding-down means and a conveying system for pressing a flat object on a conveying roller, said cylindrical holding-down means comprising at least two parts comprising a spindle and at least one sleeve, said The inner diameter of the sleeve is larger than the outer diameter of the spindle, and the holding-down means are engaged with each other, and a pin-shaped engaging member which is directed from the spindle and engaged with a cutout on at least one side of the sleeve is engaged on the spindle.

Description

Holding-down device and transport system for flat products to be transported}

The present invention relates to a holding-down means for reliably pressing a flat object onto a conveying roller and a conveying system for accurately conveying the flat object.

In the production process, the goods to be transported need to be guided through a number of production stations. In this case, while the article passes through different temperatures, pressures and mediums, it moves a certain distance at a constant speed. To this end, flat objects have so far been placed on the workpiece carriers or carried by chains or by pushing-action drives, such devices being described, for example, in EP 001 032 023 A1. And furthermore, DE 30 35 877 A1 describes rollers for roller conveyors.

DE 12 56 963 B and DE 31 40 546 A disclose a holding-down means consisting of two parts of a spindle and a sleeve, wherein the inner diameter of the sleeve is larger than the outer diameter of the spindle, An elastic coupling is provided between the spindle and the sleeve.

U. S. Patent No. 5,711, 806 also discloses a conveying system having a conveying roller and holding-down means for conveying flat objects through a chemical bath, in which case the holding-down means is flexible. It is mounted in a resilient manner.

The conveyance with the workpiece carrier can mount each article very stably and, depending on its configuration, will provide good contact between the transportable article and the surrounding media, in some cases wet chemical treatment in this state. Is performed.

However, the operation of mounting the workpiece carrier is very expensive, and in the case of mass production takes a lot of time, an unwanted cost element is generated.

In the case of the push-actuating or roller drive it is easier to mount the conveying system, in which case the conveyables are simply located in a fixed position and properly fixed depending on the application.

Using this assembly-line principle, in the case of transportation, it should be ensured that the workpiece has easy access to each processing station for processing, chemical reactions, spraying, and the like. For this purpose, in some cases a relocation has to be done, which makes the process difficult.

A particular problem is the high damage rate for sensitive materials such as thin semiconductor wafers or blanks for solar-cell production. Since each object is positioned in any way or in a freely movable manner, it is easy to deviate or lose direction by a vibration of the conveying system.

If the article is no longer positioned in the predetermined manner on the delivery system, it is difficult to fold it up for other processing or repositioning, and in some cases this phenomenon cannot occur mechanically. If the objects collide with each other, or if they move to an indeterminate position, the quality of the rest of the processing is degraded because the objects are no longer completely intercepted or placed in the correct position. In addition, there is a risk of damage when a collision with the fixed part occurs.

Another problem arises when the objects are guided into the liquid medium. If the weights of the objects themselves are not sufficient to be reliably supported or if the objects are not secured, they may be separated from the transport system by buoyancy. This problem is further exacerbated when wet chemical reactions occur, which creates bubbles and associated buoyancy.

By using holding-down means, it is possible to counter the buoyancy of the object in the liquid. In the latter case the articles are pressed onto a conveying system located directly below, but in this case the articles are subjected to a pressure of holding-down means, in particular during the introduction into the wet chemical bath and If the thickness varies, the risk of breakage is increased.

Moreover, all delivery systems have disadvantages as long as the use of chemical or temperature dependent processes is contemplated. In order to ensure uniformity and straightness of the workpiece transport, when the temperature rises, transport media such as chains, rolls, rollers or workpiece carriers should only expand within a very fine range, while at the same time the transport media may be During the treatment, it must be made of a material that does not erode itself and that does not cause a reaction.

A possible solution to this problem is presented in DE 30 35 117 A, in which a two-part roller is described. The spindle consisting of a heat resistant material such as glass fiber or carbon fiber is surrounded by an elastic chemical resistant coating. However, when the temperature changes, such a coating part undergoes relatively small changes within a certain range, thereby lowering the stability of the position and orientation of the article.

1 is a view of the spindle portion of the holding-down means,

2 is a side view of the sleeve of the holding-down means,

3 is a side view of the holding-down means according to FIGS. 1 and 2,

4 is a longitudinal sectional view along the holding-down means according to FIG. 3,

5 is a cross-sectional view of the holding-down means along the line V-V of FIG. 4,

6 is a side view of a conveying system with conveying rollers and holding-down means in accordance with the present invention;

It is therefore an object of the present invention to ensure that flat workpieces can be handled and processed continuously while being kept on the correct track as precisely as possible, and only to a low degree, under a wide range of different conditions for temperature, pressure and wrapping media. It is to provide a holding-down means and a conveying system for exposing the workpiece to the mechanical load of the workpiece.

This object of the invention is achieved by a cylindrical holding-down means having a configuration of at least two parts and having a spindle and at least one sleeve. Here, the inner diameter of the sleeve is larger than the outer diameter of the spindle, and the spindle and sleeve of the holding-down means are coupled to each other and are directed from the spindle and engaged in a cutout on at least one side of the sleeve. The carrying member is shaped on the spindle.

If the articles are to be wifeed in a tilted manner or to be contained in a chemical bath, the articles are preferably held by the holding-down means 23 (Figs. 1 to 5).

This preferably consists of two parts, FIG. 1 shows a view of the part of the spindle 8 of the holding-down means 23. The spindle 8 has a recess 10 which is located opposite the closure 9, the closure 9 being recessed 10 of another holding-down spindle (not shown). By being inserted into the spindle 8, the spindle 8 can be connected to and fixed with another spindle. The cylindrical spindle 8, in the engaged state, has a reduced diameter region 11 which is encased by the sleeve 13 (FIG. 2). At the center of the region 11 is formed a bore 12 into which a rod-shaped engagement member which functions to engage the spindle 8 and the sleeve 13 is inserted.

2 shows a side view of the sleeve 13. The sleeve 13 is directed from the outside, for example two grooves 14 on which bearing contact members 15, such as O-rings, are mounted, and in the longitudinal direction oriented in the circumferential direction 17. It has a cutout (16) having a slot shape of.

5 is a cross-sectional view of the holding-down means 23 according to the previous figures. As can be seen, a spacing A is provided between the spindle 8 and the sleeve 13, which spacing A corresponds to the workpiece tolerance. This means that relatively thick workpieces can be transported without the need for a reconditioned transport system. Thus, the spindle 8 can move in a certain amount within the sleeve 13 such that the inner wall of the sleeve 13 can collide with the outer wall of the spindle 8. Here, the rod-shaped coupling member is transmitted to the sleeve 13 by rotating in the direction in which the spindle (8) rotates. Gravity and the holding-down means 23 mounted horizontally in the conveying system cause the sleeve 13 or the contact member 15 to always strike the workpiece (even when rotating).

6 shows a schematic side view of a conveying system with a conveying roller 22 and holding-down means 23, the article 24 lying on the conveying rollers 22. Since the object is placed in the inclined guide, it is moved downward while being pressed against the conveying roller 22 by the holding-down means 23. During operation to be immersed in a wet chemical bath, the holding-down means 23 prevents buoyancy which causes the object to rise from the conveying roller 22.

List of symbols

A thickness

8 holding-down spindle

9 closures

10 recess

11 sleeve area

12 coupling member

13 holding-down sleeve

14 groove

15 contact

16 cutouts for mating members

17 direction of rotation

22 conveying roller

23 holding-down means

24 things

25 wet chemical bath

A particularly advantageous solution is to design a conveying system with a conveying roller and holding-down means in accordance with the invention for reliably conveying flat objects.

While carrying a flat object passing through a liquid material or an area where gas or liquid is sprayed onto the object, it is advantageous to use holding-down means to protect the object against buoyancy. The holding-down means according to the invention comprises a spindle and a sleeve designed in at least two parts. Here, the inner diameter of the sleeve is larger than the outer diameter of the spindle, so that the sleeve flows in a certain amount relative to the spindle, and the sleeve is fitted on the mounted spindle so that the central axis of the sleeve and the spindle are not located on a single line. Do not.

Thus, the holding-down means can be coupled to the upper portion of the clouded area so that the sleeve of the holding-down means is pressed against the objects only by its own weight. If the thickness of the articles varies, within the flow relationship between the sleeve and the spindle, the sleeve may be moved. The flow between the sleeve and the spindle exerts a constant pressure on the article, and if this flow does not exist, the articles can be pressed from below on the holding-down means, resulting in an unnecessary load, This may cause breakage.

However, if a more reliable guidance of the object can be realized, the outer diameter of the spindle and the inner diameter of the sleeve can be brought closer to each other, or the engagement member can be introduced between the spindle and the sleeve to reduce the flow between the spindle and the sleeve.

In particular, when objects of different thickness are guided under the holding-down means, the flow between the spindle and the sleeve has an advantage. In particular, it can be used for the thickness of all articles allowed by the flow between the sleeve and the spindle rather than the holding-down means which must be rejoined. In addition, in the case where the change in thickness occurs continuously, that is, when objects of different thicknesses are alternately or side-by-side guided under the holding-down means, the variability of the workpiece thickness has an advantage.

Furthermore, the members of the holding-down means can be produced independently and in parallel, which is advantageous in terms of production conditions.

The present invention provides a spindle and a sleeve to be coupled to each other. This means that the sleeve is carried together when the spindle is driven. Preferably this coupling does not consist of a rigid configuration, whereby the coupling only functions to limit this flow and the flow between the sleeve and the spindle is maintained.

According to the invention, this engagement is to engage on the spindle a pin-shaped carrying member which is directed from the spindle and engaged in a cutout on at least one side of the sleeve. The pin prevents the sleeve from moving downwardly from the spindle and also prevents free rotation about the spindle. When the spindle is driven, the sleeve is carried together, whereby the driving force is transmitted to the article.

The pins may be moved in a flexible manner and may be made of elastic material. However, in a preferred configuration, the pin is a rigid member that is directed from the spindle in the radial direction and is rigidly connected.

The pin can be engaged in the cutout of the sleeve in a shape-engaged manner to limit the flow between the spindle and the sleeve to a certain range. However, in a preferred embodiment, the diameter of the cutout is larger than the diameter of the pin in at least one direction.

In an advantageous configuration, the holding-down means has a contact member fixed on the outside of the sleeve and forming a diameter larger than the largest diameter of the holding-down means. This causes the smallest contact surface between the holding-down means and the workpiece. In the same manner as the bearings on the conveying roller, this results in careful handling of the objects, while being spaced at regular intervals for contact with the surrounding medium. An O-ring made of fluororubber is used as the contact member.

In another preferred configuration of the invention, the holding-down means can be connected together to form a predetermined length. The holding-down unit comprises, for example, a series of predetermined number of holding-down means. The manufacturer, or seller, of the holding-down means can respond very flexibly to satisfying the needs of the customer. Since a holding-down unit of a predetermined length is used, the holding-down means is a low cost mass product.

For example, the holding-down means may be inserted into one another and screwed into one another or may be connected to one another in clip and welding, which is very advantageous in production and storage.

In addition, in one development, the holding-down means can be driven to move the objects evenly.

In a preferred phrase, the cutout in the sleeve is designed as a slot such that the longitudinal length is along the circumferential direction. Thus, the degree of freedom of rotation of the sleeve is greater than the latter degree of freedom of rotation to be axially displaced. The axial displacement implies the risk of the goods changing track. In addition, the cutout presented herein allows for the above-described flow between the sleeve and the spindle while preventing the sleeve from axially displacing. The longitudinal length of the slot is preferably of sufficient length for the sleeve to lie on the spindle at each position while the holding-down means is rotating.

If the conveying system is assembled with the holding-down means according to the invention, careful handling of the objects is ensured.

A particular advantage of the conveying system is that it guides the object in the conveying roller and in the holding-down means saying according to the invention. In particular, when the articles are guided through different media, guided through sprays, nozzles, heat sinks or other treatment processes, or immersed in a bath for example wet chemical treatment, this combination is very It is advantageous. For this purpose, the workpiece must be lowered into the bath through the image conveying roller guide. The holding-down means prevents buoyancy which causes the workpiece to rise. The conveying roller with the bearing member prevents the workpiece from sliding along the slope.

Each of the conveying rollers may be aligned with the holding-down means, or the holding-down means may be engaged only in the position necessary for conveying and / or holding-down purposes.

The conveying guide can achieve a high workload with the conveying system according to the invention and at the same time handle the articles very carefully, which is particularly suitable for very sensitive objects.

Accordingly, the present invention proposes the use of a delivery system as a production line in the manufacture of solar cells. Such cells typically have a thickness of 100 to 500 μm and are formed of monocrystalline or polycrystalline silicon. Silicone is a fragile material. Thus, the cells are very fragile and therefore carry very stringent demands on the conveying system. The conveying system according to the invention allows for very careful handling of the wafer with high throughput.

In addition to the linear delivery of the cell, the delivery system may allow the cell to be submerged in a wet chemical bath and also allow two sides of the cell to be subjected to the action of a liquid or gas medium. Such applications include cleaning and etching processes (eg phosphorus glass etching). The wafer is then rinsed and dried.

Other advantages and arrangements of the invention are set forth in the claims, and can also be seen in the description and the accompanying drawings.

Claims (8)

A holding-down means for applying pressure to a flat object having a configuration of at least two parts and comprising a spindle and at least one sleeve, the inner diameter of the sleeve being larger than the outer diameter of the spindle, The spindle 8 and the sleeve 11 of the holding-down means are coupled to each other, A holding-down means, characterized in that a pin-shaped engaging member which is directed from the spindle (8) and which is coupled to a cutout (16) on at least one side of the sleeve is engaged on the spindle (8). 2. The holding-down means according to claim 1, wherein said holding-down means has at least two spaced apart contact members (15) fixed on the outside, the diameter formed by said contact members being the largest of said holding-down means (23). Holding-down means, characterized in that it is larger than the diameter. The holding-down means according to any one of the preceding claims, characterized in that the holding-down means (23) are connected to each other to form a predetermined length. The holding-down means according to any one of the preceding claims, characterized in that the holding-down means (23) can be driven. The holding-down means according to any one of the preceding claims, characterized in that the cutout (16) of the sleeve consists of a slot whose longitudinal length is directed in the circumferential direction (17). In a conveying system for carrying a flat article, having a holding-down means for applying pressure on the flat article, the cylindrical holding-down means consists of at least two parts, the spindle 8 and the at least one sleeve. (13), wherein the inner diameter of the sleeve (13) is larger than the outer diameter of the spindle (8), the spindle (8) of the holding-down means and the sleeve (13) are coupled to each other and from the spindle (8) A conveying system, characterized in that a pin-shaped engaging member is oriented on the spindle (8), which is directed and is coupled to a cutout (16) on at least one side of the sleeve. A transport system for transporting flat objects, the transport roller having at least one track member and the holding down means, wherein the track member is at least one track keeper having a diameter greater than the diameter of the track member in the outer region. having a track keeper, the cylindrical holding-down means 23 comprising at least two parts comprising a spindle 8 and at least one sleeve 13, the inner diameter of the sleeve 13 being a spindle Larger than the outer diameter of (8), the spindle (8) and the sleeve (13) of the holding-down means are coupled to each other and directed from the spindle (8) to the cutout (16) on at least one side of the sleeve. A conveying system, characterized in that a pin-shaped engaging member is engaged on the spindle (8). Use of the delivery system according to claim 6 as a production line in semiconductor or solar-cell production, in particular for wet chemical treatment of blanks such as edging and cleaning.