DE10063666C1 - Joining substrates involves pressing substrates together during rotation to form capillary gap in inner hole area as adhesive layer is forced radially outwards by centrifugal action - Google Patents

Abstract

The method involves placing a first substrate (4) on a rotary plate (6), applying an adhesive (26) near the inner hole of the substrate, applying a second substrate (3) to the surface of the first substrate with the adhesive layer and rotating the substrates to force the adhesive radially outwards by centrifugal force. The two substrates are pressed together during rotation to form a capillary gap in the inner hole area. Independent claims are also included for the following: an arrangement for joining substrates.

Description

The present invention relates to a method and an apparatus for joining two substrates with an inner hole, at which or where a first substrate is placed on a turntable Glue is applied in the vicinity of the inner hole of the first substrate second substrate on the surface of the first substrate having the adhesive is placed, and then the substrates to the radially outward Spin the glue to be rotated.

Such a method is for example for the joining of Disks to a CD or DVD known from US-A-4,877,475. At the This process, the adhesive can enter the area of the inner hole, what can cause problems there. In addition, the inner edge of the Kle layer uneven, d. H. not be circular.

Based on the above procedure, the present inventor dung the task based on a device and a method for together to create substrates with a clean inner edge of the adhesive layer located between the substrates is generated.

According to the invention, the object in a method for assembling gene of two substrates with an inner hole of the aforementioned type solved in that the two substrates while rotating to form a capillary gap in the inner hole area to be pressed towards each other. Due to the formation of the capillary gap, the adhesive is drawn towards the center hole without entering it, and further the glue is removed by the capil Larspalt counter to the centrifugal force occurring during the rotation Area kept. This allows a cosmetically clean inner edge of the Achieve glue.  

To avoid shifting the substrates while turning, they are preferably guided radially by a centering pin.

According to a preferred embodiment of the invention, the sub strate towards each other with an element covering the inner hole suppressed. The element is preferably subjected to negative pressure, to pull it to the substrates, and squeezing the sub strate to effect. The negative pressure can be applied through the element to the Force acting on substrates can be controlled well. In one embodiment the invention, the negative pressure is applied in the region of the inner hole, so that the vacuum also pulls the adhesive towards the inner hole and the Capillary action supports.

The element preferably receives the centering pin at least partially, to center the element and also a radial guide for the element provided. In an alternative embodiment, the negative pressure in a chamber formed between the centering pin and the cover placed to prevent negative pressure from developing in the inner hole area, the glue sucks into the inner hole area.

The object underlying the invention is also in a device for joining together two substrates with an inner hole a turntable for holding the substrates, a centering pin for Zen the substrates in the inner hole and a unit for. Applying one Adhesive on at least one of the substrates solved by a pressing device is provided that the substrates in the region of the inner hole towards each other suppressed. This results in the advantages already mentioned, namely, that a capillary gap can be formed between the substrates, which Adhesive between the substrates in this area holds and thus creates a clean inner edge contour of the adhesive.

In a preferred embodiment of the invention, the push has direction an element covering the inner hole, which in the area of the inner hole  rests on one of the substrates in order to press them together. The element preferably forms one with the substrates and the turntable essentially closed chamber to a sub in this area to be able to apply pressure that controls the element against the sub strate is pulled to create the capillary gap.

In an alternative embodiment, one is essentially closed sen chamber formed between the element and the centering pin to allow a vacuum to be applied in this area, which the Element pulls against the substrates and compresses them. Here ver prevents the negative pressure acting directly on the adhesive and giving it if pulls into the area of the inner hole. This points to the formation of the chamber Element preferably a recess for at least partial reception the centering pin.

In a preferred embodiment of the invention, the push has direction a vacuum source. The centering pin preferably has vacuum openings in connection with the vacuum source, via which the negative pressure in the area of the inner hole or in the area of the Chen closed chamber between the element and the centering pin is created.

The invention is described below using preferred exemplary embodiments explained with reference to the drawings; in the drawings shows:

Figure 1 is a schematic sectional view through a device according to a first embodiment of the present invention.

Fig. 2 is a schematic sectional view through an apparatus for joining substrates according to a second embodiment of the present invention;

Fig. 3 is a schematic sectional view through an apparatus for joining substrates according to a third embodiment of the present invention;

Fig. 4 is a schematic sectional view through an apparatus for joining substrates according to a fourth embodiment of the present invention;

Fig. 5 is a schematic sectional view of the device shown in Figure 4, wherein a centering pin of the device is shown in a sub strate compressing position.

Fig. 6 is a schematic representation of the Vorrich device according to the invention, the lines used in the device handling devices shows.

Fig. 1 shows an apparatus 1 for joining two substrates 3, 4. The device 1 has a turntable 6 which is rotatable in a known manner via a rotary device not shown. On the turntable 6 , a centering pin 8 is attached, which can be taken into the inner hole of the substrates 3 , 4 . The centering pin 8 has a through opening 10 which is connected to a line 12 . The through opening 10 extends ver tical through the centering pin and forms an opening 14 in the top of the centering pin 8th The line 12 is connected to the end of the passage opening 12 opposite the opening 14 and is connected to a vacuum source 16 , such as a vacuum pump.

The device 1 has a sleeve 20 with a recess 22 , in which, as can be seen in FIG. 1, a sealing element 24 , such as an O-ring, is arranged.

The device 1 also has a device, not shown, for bringing an adhesive 26 onto one of the substrates.

The operation of the device will be explained in more detail with reference to FIG. 1. In a first step, the substrate 4 is placed on the turntable 6 , the substrate 4 being guided and centered by the centering pin 8 . At closing, the turntable 6 is slowly rotated and a bead of adhesive is applied in a known manner to the upward-facing surface of the substrate 4 via the applicator device (not shown ) . At closing the application device is moved away from the area of the substrate 4 and the second substrate 3 is placed on the first substrate 4 , so that the adhesive 26 is located between the two substrates 3 , 4 . At closing the sleeve 20 is placed over the centering pin 8 that there is formed between a chamber 28 which is sealed to the environment by a sealing engagement between the centering pin 8 and the sealing element 24 . A lower edge of the sleeve 20 contacts the top of the substrate 3 and presses in the region of the inner hole on the substrate 3rd

Subsequently, the turntable 6 is rotated, is hurled whereby the straten between the sub 3, 4 adhesive 26 located radially outwardly, to form a uniform adhesive film between the substrates 3 4. By applying negative pressure to the chamber 28 , the sleeve 20 is drawn to the centering pin 8 . As a result, the lower edge of the sleeve 20 presses in the inner hole region onto the substrate 3 , as a result of which it bends slightly in the direction of the substrate 4 lying below. As a result of this bending, a capillary gap is formed in the area of the inner hole of the substrates 3 , 4 , through which uniform adhesive is sucked in the direction of the inner hole area. The capillary gap prevents the adhesive material from being thrown outwards in an uncontrolled manner and thus creates a clean inner edge of the adhesive film produced. After the even distribution of the adhesive 26 , the rotation of the turntable 6 is stopped, and the sleeve 20 is removed after releasing the negative pressure. The substrates 3 , 4 connected in this way are now removed as a unit from the turntable. The adhesive layer formed between the substrates 3 , 4 can be cured before removal of the substrates 3 , 4 , if this is necessary. Curing can also take place after removal.

The vacuum chamber 28 is formed by a seal between an inner circumference of the recess 22 of the sleeve 20 and an outer circumference of the Zen trier pin 8 . Alternatively, it is also possible to provide a pin on the sleeve 20 which engages in a sealing manner in the through opening 10 of the centering pin 8 . If now a underpressure is applied in the through hole 10, the pin sleeve 20 is drawn deeper into the through hole 10 which, in turn, the sleeve 20, the substrates 3, 4 in the loading area of the central opening suppressed to each other. In both cases, the vacuum with respect to the inner hole region of the substrates 3 , 4 is isolated, so that the vacuum for tightening the sleeve 20 has no direct influence on the adhesive 26 .

Fig. 2 shows an alternative embodiment of a device 1 to piece together of substrates 3, 4. In FIG. 2, the same reference numerals as in Fig. 1 are used, provided that the same or equivalent elements are designated net. The device 1 in turn has a turntable 6 and a centering pin 8 . An opening 30 is formed in the centering pin 8 , which extends vertically from the bottom of the centering pin 8 upwards into the centering pin and ends approximately in the center of the centering pin. From an upper end of the opening 30 further openings 32 are guided radially outwards, which are connected to a circumferential groove 34 of the centering pin 8 in United. The circumferential groove 34 lies adjacent to a gap formed between the substrates 3 , 4 .

The device 1 in turn has a sleeve 20 with a recess 22 for partially receiving the centering pin 8 . Between an inner periphery of the recess 22 and an outer periphery of the centering pin no telement is provided, as was the case in the first embodiment. When the sleeve 20 is placed over the centering pin 8 and rests on the upper substrate 3 , a substantially closed chamber 38 is formed between the turntable 6 , the substrates 3 , 4 and the sleeve 20 . The chamber 38 can via the openings 30 , 32 in the centering pin 8 , as well as the Lei device 12 and the vacuum source 16 with a vacuum, which pulls the sleeve 20 down, and the substrates 3 , 4 in the region of the inner hole on each other to press, as already described above, to create a capillary gap in the area of the inner hole. Since the negative pressure is also present in the area of the inner hole of the substrates 3 , 4 , it now also acts directly on the adhesive located between the substrates 3 , 4 and sucks it inward in addition to the capillary action.

Fig. 3 shows an alternative embodiment of a device 1 to piece together of substrates 3, 4. In Fig. 3 again the same reference numerals are used, provided the same or similar elements are referred to. The device 1 has a turntable 6 with a centering pin 8 and a sleeve 20 with a recess 22 . The sleeve 20 is made of a magnetic material, and the centering pin 8 has a magnet, in particular an electromagnet 40 , in order to pull the sleeve 20 in the direction of the centering pin 8 . Vacuum openings in the centering pin are not required in this embodiment, but can also be used. By the electromagnet, the sleeve 20 can be pulled to the centering pin 8 in a controlled manner in order to produce a capillary gap in the region of the inner hole of the substrates 3 , 4 .

Fig. 4 shows a further embodiment of a device 1 according to the invention Vorrich for joining substrates 3, 4. The device has a turntable 6 with a first pin 50 fixedly connected to the turntable 6 . The first pin 50 is received in a second pin 52 in such a way that the two pins 50 , 52 can be displaced in the axial direction relative to one another, but cannot be rotated relative to one another.

The first pin 50 has at its upper end a conically tapering guide tip 54 , the function of which will be explained in more detail below. In the second pin 52 horizontally extending pressure pins 56 are also seen before, two of which are shown in Fig. 4. The pressure pins 56 can be displaced radially outward within the second pin 52 , as can be seen in the illustration according to FIG. 5. The pressure pins 56 are biased radially inward via a device, not shown, in the position shown in FIG. 4 Darge.

By axially displacing the two pins 50 , 52 from the position shown in FIG. 4 to the position shown in FIG. 5, the conical tip 54 of the first pin 50 engages with the pressure pins 56 and pushes them radially outward against their bias, so that they protrude beyond the outer periphery of the first pin 52 and come into engagement with an upper surface of the upper substrate 3 . As can be seen in Fig. 5, this allows the upper substrate 3 to be bent in the interior to form a capillary gap in the loading area of the inner hole between the substrates 3 , 4 . When the adhesive 26 is thrown out, it is thus held securely in this area. The displacement of the two pins 50 , 52 relative to one another can be achieved by any suitable means.

The joining of the substrates 3 , 4 takes place in the above-mentioned exemplary embodiments in each case essentially in the manner described with reference to FIG. 1, but the generation of a capillary gap between the substrates 3 , 4 during the ejection of the adhesive 26 different way is generated.

Fig. 6 shows a schematic representation of the device 1 Vorrich invention for joining substrates. In particular, Fig. 6 a handling mechanism 60 for loading and unloading a sleeve 20 according to the embodiments of FIGS. 1 and 4. Further, a handle lo exercise mechanism 62 is shown for loading and unloading of the substrates.

The handling mechanism 60 has a vacuum gripper 64 which is attached to an L-shaped swivel bracket 66 with a short leg 67 and a long leg 68 . The vacuum gripper 64 is attached to one end of the long leg 68 and points in the same direction as the short leg 67 of the bracket 66 . At the free end of the short leg 67 , the bracket 66 is pivotally mounted about a shaft 70 . The bracket 66 has on the long leg 68 an opposite to the short leg pointing to set 72 , which is rotatably connected via a shaft 74 to a push rod 76 of a cylinder 78 . By extending or retracting the push rod 76 , the bracket 66 can be pivoted about the shaft 70 . In a retracted position of the push rod 76 , the bracket 66 and thus the vacuum gripper 64 is pivoted away from the substrates 3 , 4 . When the push rod 76 is extended, the bracket 66 is pivoted in the direction of the substrates 3 , 4 and in particular towards the sleeve 20 .

The vacuum gripper 64 is able to pick up the sleeve 20 and move it out of the working and movement area of the handling device 62 in order to enable loading and unloading of the substrates 3 , 4 .

The device was previously based on preferred embodiments of the Invention described, but without referring to the specific embodiments to be limited. In particular, other devices can be provided to the two substrates to create a capillary gap inside to press the hole area towards each other. The individual characteristics of the execution Examples can come together in any compatible way be binated.

Claims (14)

1. Method for joining two substrates having an inner hole, with the following method steps:

• Depositing a first substrate on a turntable,
• - Applying an adhesive near the inner hole of the first sub strate,
• - placing a second substrate on the surface of the first substrate having the adhesive, and
• - turning the substrates radially outwards to spin the adhesive,

characterized in that the two substrates are pressed towards one another during the rotation to form a capillary gap in the inner hole region. 2. The method according to claim 1, characterized in that the substrates be guided radially by a centering pin during turning. 3. The method according to any one of the preceding method claims, characterized characterized in that the substrates with a covering the inner hole Element are pressed towards each other. 4. The method according to claim 3, characterized in that the element with Vacuum is applied. 5. The method according to claim 4, characterized in that the vacuum in Area of the inner hole is created. 6. The method according to any one of claims 3 to 5, characterized in that the element at least partially receives the centering pin.   7. The method according to claim 6, characterized in that the sub pressure in a cam formed between the centering pin and the cover is always created. 8. Device ( 1 ) for joining together two substrates ( 3 , 4 ) having an inner hole, with a turntable ( 6 ) for receiving the substrates, a centering pin ( 8 ; 50 , 52 ) for centering the substrates ( 3 , 4 ) in the inner hole and a unit for applying an adhesive ( 26 ) to at least one of the substrates ( 4 ), characterized by a pressure device which presses the substrates ( 3 , 4 ) towards one another in the region of the inner hole. 9. The device according to claim 8, characterized in that the Drückvor direction has an inner hole covering element ( 20 ) which rests in the loading area of the inner hole on one of the substrates ( 3 ). 10. The device according to claim 9, characterized in that the element ( 20 ) with the substrates ( 3 , 4 ) and the turntable ( 6 ) forms a substantially closed chamber ( 38 ). 11. The device according to claim 9, characterized in that the element ( 20 ) with the centering pin ( 8 ) forms a substantially closed chamber ( 28 ). 12. The device according to claim one of claims 9 to 11, characterized in that the element ( 20 ) has a recess ( 22 ) for at least partially receiving the centering pin ( 8 ). 13. Device according to one of claims 8 to 12, characterized in that the pressing device has a vacuum source ( 16 ). 14. The apparatus according to claim 13, characterized in that the centering pin with the vacuum source ( 16 ) communicating vacuum openings ( 10 ; 30 , 32 ).