DE102008060014A1 - Method and apparatus for handling a sawn wafer block - Google Patents

Abstract

Disclosed is a method of handling a sawn wafer block sawed into individual wafers still held by the support means. From both sides brushes are moved horizontally with bristles on the sawed wafer block, which extend laterally to the side edges of the wafers and into spaces between the wafers to hold them and keep them at a distance. The brushes have a longitudinal extent along the sawed wafer block and are movable along this longitudinal extent. The sawn wafer block is brought from the horizontal position into a vertical position with simultaneously pressed brushes. Then the brushes are moved from top to bottom along the sawed wafer block pulling their bristles out of the spaces between the individual wafers to lower the individual wafers directly to each other without gap to a wafer stack.

Description

Field of application and status of the technique

The The invention relates to a method and a device suitable for this purpose for handling or turning a sawn wafer block, especially after sawing a wafer block into individual ones Wafer for the production of solar cells.

From the DE 10 2008 053 596.6 as well as the DE 10 2008 053 598.2 It is known to saw a wafer block, which is glued along at least one side to a support and is fixed to the carrier on a support means, into individual wafers and then to clean. As a result, sawing residues are eliminated. Furthermore, then, as in the DE 10 2008 053 598.2 described, the sawed wafer block or the individual wafer from the carrier dissolved by dissolution or removal of the adhesive. The sawed wafer block is in a horizontal position, so the individual wafers are vertical. After releasing the bond with the carrier, the wafers are held in the carrier device or are fixed, preferably by Anlie conditions on lateral, elongate holders such as side brushes according to the DE 10 2005 028 112 A1 or rod-like supports. In this carrier device, the wafers are then erected in a vertical position so that they lie flat. Thus, a stack is formed, from which the wafers can then be removed automatically. Alternatively, they can also be removed manually from the carrier device and rotated and fed to further processing, for example a batch production line.

Manually However, handling the wafers is considered disadvantageous as it is Often the wafers are damaged or destroyed and costly. A previous automatic turning into one vertical position is possible. The release and discharging the wafers to a stack directly one above the other Wafers, however, are also often at risk of damage or destruction, especially since it is not exactly controlled can be performed.

Task and solution

Of the Invention is based on the object, an aforementioned method and to provide a corresponding device with which the disadvantages of the prior art can be solved and in particular, turning a sawn wafer block as well forming a vertical stack of wafers, that is, vertical Position, to allow for low risk of damage for the wafers.

Solved This object is achieved by a method having the features of the claim 1 and a device with the features of claim 9. Advantageous As well as preferred embodiments of the invention are the subject of further claims and will be closer in the following explained. Some of the listed below Features are only for the procedure or only for called the device. However, they should be detached from it both for the process and for the corresponding de Device can apply. The wording of the claims becomes by express reference to the content of the description made.

It it is envisaged that the waferblock sawed into individual wafers or just the individual wafers still on the carrier device being held. This is advantageously done on at least two sides, preferably on opposite sides. According to the invention to the wafer block in the horizontal position of two opposite Pages, especially horizontally opposite, brushes with Bristles or slats moved up. This is done in such a way that the Bristles or lamellae not only laterally to the side edges the wafers reach, but in the spaces between into the individual wafers. Due to the pressure of the Bristles or fins can not only keep the wafers at a distance be kept so the interstices are obtained but also the wafers themselves are kept in their position. This enables the later described release from the carrier without the wafers moving or fall down. The brushes have a longitudinal extent along of the sawn wafer block, so that they are on all Wafers abut. They are along this longitudinal extent movable, in particular in the direction of this longitudinal extent. The sawed wafer block is pressed with Brushes from the horizontal position to a vertical one Positioned, so erected. Then the brushes From top to bottom either moves so that the bristles or lamellae be moved out of the wafers in some areas, or over the entire length to the same extent. Advantageous The brushes are taken along the length direction moved from top to bottom and thus pull all the bristles or lamellae at the same time out of the gaps. This will be the interstices can no longer receive and the wafers can Lowering each other to form the wafer stack, in which the wafers rest directly on each other.

Thus, it is thus possible with the invention not only to hold the wafers of the sawn wafer block with the brushes in order to bring them into a vertical position, but also to improve the stacking of the wafers spaced apart by the interstices without mechanical damage. If the bristles or fins soft ge are formed nug and finely enough, they can fill both very thin spaces with simultaneous holding function and also fulfill a certain holding and distance-keeping function when pulling out, even if the distance is still much lower than at the beginning, so not more 100 microns to 200 microns, but 20 microns to 50 microns or the like .. Furthermore, such soft bristles or lamellae can be moved laterally to the wafer zoom and into the interstices without damaging the side edges.

In Another embodiment of the invention, the erection of the sawed Wafer blocks from the horizontal position to the vertical position done in a water bath. This can be sawed horizontally lying Wafer block either moved into a corresponding water bath or it can be formed around it.

In repeated development of the invention, it is possible removing the brushes or lowering or destacking the individual wafer on a wafer stack also in a water bath perform. Again, the above options apply for the water bath. The advantage of movement or handling the wafer or the sawn wafer block is in a water bath in that mechanical forces due to the floating of the Wafers stay lower. Above all, the lowering or destacking the wafer on top of each other can be gentler through the water bath and so to speak steamed. Furthermore, in a stacking the wafer in a water bath simultaneously lowering the water level.

One Another advantage of moving down brushes with it down moving bristles or lamellas is that these on the one hand pulled down and on the other hand, however move the wafers down, so to speak. This is a very accurate Controllable destacking because the bristles or lamellae are the wafers still lead.

In Another advantageous embodiment of the invention, the bristles or slats evenly from the interstices pulled out or the brushes are consistent Speed moves down. Alternatively, the speed As the stacking process progresses, it becomes smaller as much as possible to achieve a gentle stacking.

In Another embodiment of the invention is in addition to an advantageous selectable Elasticity and thickness of the bristles or lamellae on it To make sure that these are not with too much of a share their length in the spaces between the Retract wafers. It can be achieved that one still sufficient length of the bristles or slats outside the wafer remains to be bent down during movements. So they stand with not too oblique angle in the interstices into it. This could be a gradual one Stacking the wafer negatively affect, because the slanted ends of the bristles or fins otherwise could push the wafers apart again.

The Brushes can in one embodiment of the invention not only be significantly longer than the wafer stack, but even be formed circumferentially, so as a kind of circulating loop. Here, for example, training on the type of tapes is suitable with the protruding bristles or lamellae, so to speak brush belts. They are then on the two opposite sides on the wafers or are with their bristles or fins in the Gaps pressed in.

Also while they can turn around they can still abut the wafers.

alternative can bar brushes as moving brushes be provided with the appropriate width. It can also be over a certain width distributes two or three very narrow brush bands or Rod brushes are used. The advantage of several such Narrow bar brushes are in that they are retractable not just the bristles or fins in the interstices can be approached with a movement directly on the wafer, but moved very close with the bristles or lamellae turned away become. By turning around its longitudinal axis can then the bristles or fins are screwed laterally, so not only with the tip ahead in the longitudinal direction of the bristles be pressed in, but with a certain length at the same time, which allows easier entry. A similar effect can be achieved when the brush while moving parallel to the side edge of the wafer is moved.

The Brushes should have a certain width, for example at least half as wide as the wafers, advantageously a little wider. They should be moved in a central area to the sawn wafer block and be applied to keep the wafers well and also against tilting to protect.

It is possible to form the brushes as constituents of the carrier device, ie to fasten them to the carrier device. Then the erection of the sawed-wafer block and also the stacking takes place so to speak with the carrier device. Alternatively, the brushes may be disposed on a separate device and, as it were, remove the sawed wafer block from the support means in the horizontal position for erecting and destacking.

These and other features are excluded from the claims also from the description and the drawings, wherein the individual features in each case alone or to several in the form of subcombinations in one embodiment of the Invention and other fields be realized and advantageous as well as for protectable versions represent protection here becomes. The subdivision of the application into individual sections as well Intermediate headlines limit those among them statements made in their generality.

Brief description of the drawings

embodiments The invention are shown schematically in the drawings and will be explained in more detail below. In the drawings demonstrate:

1 an oblique view of a sawed wafer block in a device according to the invention with two lateral brush belts,

2 a highly schematic sectional view through the wafer stack 1 with the application of the side brushes and

3 a schematic representation of the stacking of the wafer in the vertically erected wafer stack by moving the brush belts.

Detailed description the embodiments

In 1 is a sawed wafer block 11 shown, like the 2 and 3 make it clear from a variety of wafers 12 exists with lateral side edges 13 , The wafers 12 each have gaps 14 to each other. This is also apparent, for example, from the German patent application filed on the same day by the same applicant with the internal character P 49143 DE, to which reference is expressly made.

The sawed wafer block 11 is according to 1 horizontal, that means the individual wafers 12 stand vertically. He is doing in a carrier device 15 held a frame-like top plate 16a and a lower plate 16b having. Such a carrier device is in the aforementioned DE 10 2008 053 596.6 to which reference is expressly made.

In addition to support rods not shown, the support means 15 in the longitudinal direction of the wafer block 11 side brushes 18 on, as in the aforementioned DE 10 2008 053 596.6 as well as in the DE 10 2005 028 112.5 are described. These side brushes 18 also extend over the length of the wafer block 11 and serve both for holding and for spacing the wafers 12 , Although they may be rotatable but not movable along the wafer block.

Furthermore, brushes are 20 provided, the elongated bristles 21 exhibit. These bristles can be relatively thin, for example, thinner than 20 microns or even thinner than 10 microns, and have a length of a few centimeters. In the 1 and 3 are the brushes 20 as revolving brush bands 23 trained, which revolves around 24 run, with the revolving wheels 24 powered and on brush holders 25 can be held.

In 2 is shown schematically as shown at the left side edge 13 of the wafer 12 who is still in the carrier device at this time 15 and supported by this, the side brushes 18 at the wafer block 11 abutment or their bristles in intermediate spaces 14 between the wafers 12 intervention. The brush 20 is still laterally beside it with a certain distance. This corresponds approximately to the illustration according to 1 in which the brush straps 23 relatively close to the sides of the wafer block 11 are, but not yet.

The next step is by moving the brush holder 25 towards each other the pressure brush 20 , as on the right side edge 13 of the wafer 12 in 2 is shown, brought up according to the thick arrow and lies with the bristles 21 not only on this side edge 13 at. The bristles 21 penetrate into the interstices 14 between the individual wafers 12 one that is easy to imagine. This penetration depth can be a few millimeters to a few centimeters.

This pressing movement of the pressure brushes can either 20 according to the illustrated thick arrow exactly on the side edge 13 to be done. Alternatively, a certain oblique movement can take place at the same time, for example from top to bottom. By such an oblique movement can, as is easy to imagine, the retraction of the bristles 21 in the interstices 14 be relieved.

In a next step, the side brushes 18 the carrier device 15 removed or moved away. In addition to this, further support rods or the like. the carrier device are removed. In particular, it is possible that even the whole carrier device 15 is removed, which is usually not necessary and technically difficult to implement due to the cage-like structure.

Subsequently, the wafers 12 only on the side of the brushes 20 held and no longer through the side brushes 18 or other lateral support rods of the support means 15 , With a bottom, they can still continue on support rods of the support device 15 rest, but this is not absolutely necessary and could even interfere with the stacking.

Subsequently, the erecting of the horizontal wafer block takes place 11 in the in 3 illustrated vertical position. Of course, this is done with brush straps 23 on the brush holders 25 simultaneously to the carrier device 15 himself. This erection can, as described above, take place in a water bath, since it is then gentler possible.

Below the wafer block 11 there is a holding plate 26 , This can either already in the carrier device 15 be present or be introduced separately. In any case, it serves the individual wafers 12 on her, as will be explained in more detail below.

The procedure for depositing the wafers or destacking is as follows. The brushes 20 or the brush bands 23 move at the side edges 13 the wafer 12 downward. As a result, on the one hand all wafers 12 moved down and lie more and more successively from bottom to top starting on the holding plate 26 on. This is illustrated by the fact that in the upper area a wafer stack 28 still with distances between the wafers 12 is shown, which are already smaller than the spaces at the same time 14 , In the lower area lies on the retaining plate 26 already a lowered wafer stack 29 before, in which the distances are only very small or, for example, at the very bottom, already no longer available.

Furthermore, when moving the brush straps tighten 23 down their bristles 21 slowly out of the gaps 14 out. This also serves to ensure that fewer and fewer spacers between the wafers, so to speak 12 are and these approach each other more and more, which leads just to the described stacking down. The advantage of this method is that the distance reduction is gradual. Furthermore, during this reduction in the distance through the brush belts 23 and their adjacent bristles 21 nor a guide or a guided movement of the wafer 12 reached.

As described above, the stacking, similar to the erection, can be done in a water bath or under water. As a result, a gentle process is possible, especially because the water in the interstices 14 between the wafers 12 the movement dampens and prevents two wafers from colliding with their sides.

It's easy to imagine how, instead of the rotating brush bands 23 elongated brushes may be used which are rod-like similar to the side brushes 18 , For them then just a longitudinal guide is needed and a device to move them along. It is important in the invention namely, that the bristles of the brushes are not simply moved laterally out of the spaces, similar to the previous for the side brushes 18 by unscrewing in the cited prior art is described. The movement of the brushes and their bristles together with the wafer stack in the direction of stacking is advantageous for a gentle and controlled process.

Instead of continuously rotating brush bands 23 over their entire length when stacking on the wafer stack 28 and 29 abutment, could also dashed lines shown pressure rollers 31 be provided. These can be at the top of the wafer block 11 starting to move downwards as illustrated by the double arrows. Simultaneously with this movement, the upper circulating rollers 24 away from the wafer block 11 be moved and thereby, either alone or in addition to the circulation of the brush belt 23 , her bristles 21 in the longitudinal direction of the spaces 14 the wafer 12 pull out. Alternatively, such pressure rollers could 31 drive from bottom to top and then just the lower rollers 24 moved away sideways.

After destacking to the lowered wafer stack 29 can the brush holder 25 drive away from the side and the vertical stack of wafers 12 can on the retaining plate 26 be removed. He can then be transported to a separation, as in the DE 10 2007 061 410 A1 is described.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 102008053596 [0002, 0024, 0025]
• - DE 102008053598 [0002, 0002]
• - DE 102005028112 A1 [0002]
• - DE 102005028112 [0025]
• - DE 102007061410 A1 [0039]

Claims (11)

A method for handling a sawn wafer block, wherein the wafer block is sawed into individual wafers and the individual wafers are held by a carrier device, characterized in that brushes with bristles or lamellae are moved from two sides to the sawn wafer block in a horizontal position and laterally the side edges of the wafers extend into and out of the spaces between the wafers to hold them or to keep them at a distance, wherein the brushes have a longitudinal extent along the sawed wafer block and are movable along this longitudinal extent, wherein the sawed wafer block with simultaneously pressed brushes from the Horizontal position is brought into a vertical position and then the brushes are moved from top to bottom along the sawn wafer block and thereby pull out their bristles or fins from the spaces between the individual wafers for lowering the individual wafers directly on each other he without gap to a wafer stack. Method according to claim 1, characterized in that that raising from the horizontal position to the vertical Position takes place in a water bath. Method according to claim 1 or 2, characterized that removing the brush or lowering the individual Wafer on a wafer stack in a water bath. Method according to claim 2 or 3, characterized that simultaneously with the stacking of the wafers through each other Move the brushes down and pull out the bristles or lamellae from the spaces between the wafers of the Water level is lowered by draining water, preferably such that the formed wafer stack is always complete is immersed. Method according to one of the preceding claims, characterized in that the brushes with a constant Speed to be moved down. Method according to one of the preceding claims, characterized in that the brushes formed circumferentially are, in particular on the type of tapes with the protruding Bristles or lamellae, preferably at two opposite Sides of the wafer stack to attack the individual wafers. Method according to one of the preceding claims, characterized in that the brushes are exactly parallel to the side edges of the sawn wafer block. Method according to one of the preceding claims, characterized in that the sawed wafer block in a stacking device is introduced which the brushes has, and in this both the brushes to the sawed Wafer be moved up as well as the sawed wafer block erected from a horizontal position to the vertical position and then the individual wafers are stacked. Apparatus for carrying out the method according to one of the preceding claims, characterized that it has at least one brush with protruding Lamellae or bristles that are very thin, preferably comprises two brushes. Device according to claim 9, characterized in that that the brushes are formed circumferentially, in particular in the manner of bands with protruding bristles or lamellae, preferably having two brushes at two opposite sides of the wafer stack to the individual Attack wafers. Device according to claim 9 or 10, characterized that the brushes with their broadside parallel to the sides the wafers are running, preferably the brushes something are less wide than the side edges of the wafers, in particular just over half as wide.