WO2002067647A2

WO2002067647A2 - Bonder

Info

Publication number: WO2002067647A2
Application number: PCT/DE2002/000570
Authority: WO
Inventors: Michael Geringer
Original assignee: Michael Geringer
Priority date: 2001-02-23
Filing date: 2002-02-19
Publication date: 2002-08-29
Also published as: AU2002247599A1; DE10109009C2; WO2002067647A3; DE10109009A1

Abstract

The invention relates to a bonder for small components, comprising a transfer device, which transfers the components from a pick-up or receiving position to a component part that is available at the bonding position and which carries out the precise positioning and bonding of said components to the component part.

Description

Bonder

The invention relates to a bonder according to the preamble of claim 1.

Transfer devices or bonders are known in particular as so-called chip or die bonders (DE 195 10 230 C2), with which first components, for example semiconductor chips, are picked up by a pick-up element at a pick-up position and from this pick-up element a bonding position on a component available there, for example on a second component, a substrate or an assembly or, for example, in a lead frame by bonding. Particularly with extremely small components, this transfer and bonding requires a high level of accuracy, in particular with regard to the location and orientation of the first components, depositing and bonding. In the known device, the transfer device has a double arm, which is pivotally mounted in the center about a vertical axis and has a pick-up element at both ends, so that each time the arm is pivoted through 180 °, a pick-up element Element received at the receiving position first component reaches the bonding position. By attaching the pick-up elements each to a partial arm of the double arm, it is possible to provide the components, for example a wafer having these components or a chip, at the receiving position on an XY table and to control them in such a way that the individual Components are removed one after the other. In the same way, it is then also possible to also provide an X-Y table at the bond position in order to allow alignment in the axial directions perpendicular to the swivel axis (Z axis) of the double-arm carrier before the actual bonding.

Although very high positioning and orientation accuracies can be achieved with these known bonders during bonding, they are relatively long Paths for the pick-up elements are required, which impairs the performance, ie the number of components processed per unit of time.

The object of the invention is to show a bonder that ensures high accuracy with regard to the positioning and orientation of components during bonding at high performance.

To solve this problem, a bonder is designed according to claim 1.

The special feature of the bonder according to the invention is that the pick-up elements only have to perform extremely small movement strokes at the receiving position and at the bonding position, that is to say they transfer first components in a very short time at the receiving position to the component receptacles of the transport element and at the bonding position can be removed from the component receptacles for bonding, long distances for the pick-up elements which impair the performance of the bonder are thus avoided.

In a preferred embodiment of the invention, at least one pick-up element, for example the pick-up element provided at the receiving position, can only be moved in one axial direction perpendicular to the direction of movement of the transport element, in such a way that with this pick-up element the recess or opening provided between two component receptacles in the transport element is grasped and received through the respective first component and this component is then placed on the next component receptacle adjacent to the recess. Developments of the invention are the subject of the dependent claims. The invention is explained in more detail below with reference to the figures using exemplary embodiments. Show it:

1 shows a simplified perspective partial representation of an embodiment of the device according to the invention as a bonder for the highly precise mounting of the smallest components on assemblies; Figure 2 shows the device of Figure 1 in a schematic representation and in plan view. 3 shows an enlarged illustration of the assembly or bonding position together with an assembly arranged at this position and a component placed on the assembly; Fig. 4 in a schematic, perspective view, the recording position of the

Device of Figure 1; Fig. 5 shows the bonding position of the in a schematic, perspective representation

Device of Figure 1; Fig. 6 is a representation similar to Figure 2 in another possible

embodiment; 7 shows a simplified representation and a top view of a component placed in an assembly or on a substrate; 8 shows a further possible embodiment in a representation similar to FIG. 6; 9 - 11 in illustrations similar to FIG. 2 further embodiments of the device according to the invention.

For better explanation, the three spatial axes running perpendicular to one another, namely the X axis, Y axis and Z axis, are shown in the figures. The device generally designated 1 in FIGS. 1-5 is used for high-precision positioning and bonding, ie for the high-precision placement and connection of “first” components 2 with extremely small dimensions on already partially manufactured modules 3. The components 2 in the embodiment shown are optical Components that have several functional elements, for example prisms for deflecting a laser beam and lenses for beam collimation or focusing.

In the embodiment shown, the assemblies 3 consist of a substrate 4 with conductor tracks, contact areas, etc., on which, in addition to optical components, for example prism-like components acting as mirrors, a laser diode 6 is also preassembled. The placement of the components 2 and the bonding of these components on the respective assembly 3 must be carried out with high precision in order to achieve the desired profile for the laser beam 6 '.

As FIG. 2 shows, the device 1 has a turntable 7 which is driven by means of a high-precision servo motor 8 (FIG. 1) about a vertical device axis. On the turntable 7, radially projecting web-like holding arms 9 are provided, which are spaced apart from one another on the circumference of the plate by the angular amount, which corresponds to two rotation steps or an integer multiple thereof. On the holders 9 receptacles or nests 10 are formed, the shape of which is adapted to the components 2, in such a way that in each nest 1 there is space for a component 2 in a precisely predetermined orientation and position.

The components 2 are fed in a belted form at a receiving position 11, ie they are located there in a precisely defined position and orientation in recordings of a belt 12. In the embodiment shown, the belt 12 becomes radial to vertical in synchronism with the movement of the turntable 7 Axis (Z axis) fed this turntable, in such a way that at the beginning of each work cycle there is a component 2 for reception by a reception or pick-up element 13 there. The latter is formed by a vacuum holder or a vacuum pipette which can only be moved up and down between three stroke positions in the vertical direction, ie in the axial direction parallel to the vertical axis of rotation of the turntable 7 (Z axis) by a drive 14 (FIG. 1) is, namely between

an upper starting position in which the lower end of the pick-up element 13 is at a level above the level of the orbit of the nests 10,

a lowermost stroke position, in which the lower end of the pick-up element 13 for receiving one component 2 each is at a level below the plane of movement of the nests 10, and

- An intermediate stroke position, in which the lower end of the pick-up element 13 for depositing a component 2 in a nest 10 is approximately in the plane of movement of the nests 10.

The arrangement is also such that the receiving position 1 1 is below the path of movement of the holder 9. The pick-up element is arranged with its vertical central axis on an imaginary circular arc around the axis of rotation of the turntable 7, which passes through the center of the nests 10.

The pick-up element 13 is located in the receiving position 11 directly above the belt 12 and is moved synchronously with the rotary movement of the turntable. In each work cycle starting with a position of the turntable 7, in which there is no nest 10 above the receiving position 11, the pick-up element 13 is first moved into the lowest position for receiving the component 2 provided in the belt 12 and then back to the uppermost position, so that after the rotary step of the turntable 7 has been completed, the component 2 in question is introduced into the ready nest 10 by lowering the pick-up element 13 can. Subsequently, the pick-up element 13 is moved again into the uppermost position, from which it is again in a new work cycle after a further turning step of the turntable 7 between two successive holders 9 on the periphery of the turntable 7 until a new, at the receiving position 1 1 available component 2 can be lowered.

Due to the described design and method of operation, only short strokes in only one axial direction, namely in the vertical axis, are necessary for the pick-up element 13, so that in a short time a large number of components 2 from the belt 12 into a nest 10 each Turntable 7 can be transferred.

With the turntable 7, which is driven by the drive 8 in the clockwise direction (arrow A) selected for FIG. 2, the components 2 reach the bonding position 15, at each of which an assembly 3 is available in a precisely predetermined position and orientation , The assemblies 3 are arranged in the embodiment shown in receptacles 16 of a conveyor belt 17, which is clocked and moved with high accuracy in the direction of arrow B, in such a way that this conveyor belt or its horizontal conveying direction B at the bond position 15 tangential to circular movement path of the holder 9 or nests 10 runs. Just like the pick-up position 11, the bond position 15 is also in a plane below the plane of the orbit of the holders 9 and nests 10. At the bond position 15, a pick-up element 18 is provided, which in the embodiment shown is designed as pliers and with which each component 2 at the bond position 15 in a nest 10 is removed from this nest and placed with high precision on the module 3 at the bond position 15 at a predetermined position and in a predetermined orientation and held until the connection (Bonding) the component 2 with the assembly 3 in the chosen manner, for example by gluing, soldering or welding using a laser beam, etc.

For this purpose, the pick-up element 18 is provided on a pick-up head 19, which controls a controlled movement of the pick-up element 18 not only in the vertical Z-axis, but also in the X-axis and the Y- Axis and possibly also a rotation around the Z axis.

- In the vertical direction (Z axis), the pick-up element 18 can in turn be moved essentially between three positions, namely between

an upper starting position in which the pick-up element 18 is located above the path of movement of the nests 10,

a first, lowered position, in which the pick-up element 18 is lowered onto the nests 10 for gripping a component 2, and

- A third position in which the pick-up element for placing the component 2 on a module 3 is lowered to the level of these modules 3.

In detail, the method of operation is such that when a nest 10 is at the bond position 15 and below the pick-up element 18 which has been raised to the starting position, the latter is lowered, namely to grasp the component 2. Subsequently, it becomes the pick-up element 18 is raised again and, after the turntable 7 has been rotated, lowered onto the assembly 3, so that the component 2 is then placed there in the required positioning and orientation.

The removal of the components 2 from the nests 10 and the placement of these components on the respective assembly 3 again takes place essentially only by lifting the pick-up element 18 in the vertical direction (Z axis). Only for the precise alignment of the respective component 2 before the actual bonding may also result in a movement of the component 2 in the X and / or Y axis and / or a rotation about the Z axis. The control here is carried out by a vision system 20, which essentially consists of at least one video camera and an image processing system which cooperates with it. As also indicated in FIG. 3, this vision system 20 is designed in such a way that the component 2 held by the pick-up element 18, but also the assembly 3, are detected with the system during bonding, so that then by appropriate Activation of the pick-up head 19 and thus the pick-up element 18 can align the component 2 to predetermined markings, edges, etc. on the assembly 3 (for example edge 21 of FIG. 3). In order to achieve high accuracy, the vision system with its optical axis (Z-axis) is located exactly above the bond position 15 and covers the working area (bond position 15) when it is deposited and bonded through the space between two carriers 9. As shown, the pick is -Up element 18 designed so that it is led out obliquely from the field of vision of the vision system 20 and the pick-up head 19 is outside the image area of this system.

Each work cycle of the device 1, in which at the pick-up or pick-up position 1 1, the installation element 2 with the pick-up element 13 there is removed from the belt 12 and inserted into a nest 10 and at which at the bond position 15 an the component held there pick-up element 18 placed on an assembly 3 and then another component is removed from a nest 10 for the next working cycle, thus comprises two phases and two rotary steps of the turntable 7, in the first phase at the receiving position 1 1 the picking up of a component 2 from the belt 12 and at the same time at the bonding position 15 the application of a component 2 to an assembly 3 and in the second phase the depositing of a component 2 in a nest 10 and at the bonding position Removing a component 2 for the next working cycle. In each phase, the pick-up elements 13 and 18 each move from their upper position into one of the lower positions and back again into the upper position.

In principle, there is of course the possibility that the vertical movement (Z axis) of the pick-up element 18 is also effected by the drive 14. Furthermore, there is the possibility of providing a vision system 22, for example for monitoring the proper functioning, also in the area of the receiving position 11 and a further vision system 23 in the direction of rotation A of the turntable 7 after the bonding position 15, for example to monitor the nests 10 and to detect a component 2 possibly remaining in a nest 10, specifically to generate an error message. Furthermore, the vision system 22 can also take over the function of the vision system 20 if a bond position is formed in the area of the vision system 23, specifically in another application of the device 1.

The advantage of the device 1 consists essentially in the fact that with this device 1 the components 2 are positioned and bonded to the assemblies 3 with high precision. The high output results in particular from the fact that essentially only short strokes in the vertical direction (Z axis) are necessary for the pick-up elements 13 and 18 and for the pick-up element 18 additionally only for adjustment in μm. Range is also movable in the direction of the X-axis and Y-axis and, if necessary, rotatable about the Z-axis, in each case by a small amount.

The assemblies 3, which are removed from a magazine 24, are fed with the transporter 17 for further processing or assembly after the components 2 have been bonded. Various monitoring and measuring elements or positions are located on the conveyor 17. FIG. 6 shows the bond position 15a again in a simplified representation in a further possible embodiment of the device according to the invention. This device, generally designated 1 a in FIG. 6, corresponds in its design to device 1, but with a somewhat different design to bond position 15 a. At this position, with the aid of the pick-up element 18, components in the form of laser diodes 6 are placed on the substrate 4 in a precisely predetermined position, specifically monitored by the vision system 20 and oriented to predetermined reference points or edges 21 the substrate 4 (Figure 7). The special feature of the embodiment in FIG. 6 is that the tool or pick-up element 18 is provided on a tool carrier 25 which is fastened to an arm 27 by means of a rotary bearing 26 so that it can rotate about the Z axis. The arm 27, on which a sensor 28 for measuring the bond force is also provided, is connected to an X / Y drive of the otherwise not shown pick-up head for movement in the X-axis and Y-axis. The carrier 25 can be rotated about the Z axis with an actuator (not shown). The sensor 28 is, for example, one with a strain gauge.

A central opening 29 is provided in the carrier 25, through which the vision system 20 detects both the substrate 4 and the component, namely the laser diode 6, in particular also during adjustment and bonding. The bonding itself, i.e. the bond connection between the laser diode 6 and the substrate 4 takes place by eutectic bonding or soldering, using a laser beam 30 with which the substrate 4 is partially heated for this purpose. Other connections, for example adhesive connections, are of course also possible here.

FIG. 8 shows, as a further possible embodiment, the bond position 15b of an otherwise not shown device 1b, with the components in shape special optical elements 31 are mounted on assemblies 3b, each with a laser diode 6 and a spacer 32, the spacer 32 being formed on an area 33 as an optical mirror. For aligning and bonding the component 31, which also has a lens 34, which must be centered exactly in the beam path of the laser beam 6 'of the laser diode 6 reflected on the mirror 33 in the direction of the Z axis, the bonding position 15b also has, among other things, electrical contacts 35 , via which the laser diode 6 can be connected to a voltage source. With the help of the vision system 20, which also detects the laser beam 6 ′ of the laser diode 6 that is collimated or focused by means of the lens 34, the component 31 is positioned in such a way that the desired optimal focusing or collimation of this laser beam is achieved. Instead of the pick-up element 18, a pick-up element 18b is used, which is designed as a vacuum holder and consists of a translucent material, for example glass, so that in any case the laser beam 6 'passing through the lens 34 from the Vision system 20 can be captured. In the beam path of this laser beam 6 ', a semitransparent mirror 36 is also provided in the illustrated embodiment, via which an outer laser beam 36 of a laterally arranged laser can be directed onto the spacer 32 in order to produce a eutectic bond connection by heating this spacer 32 or else one cure the adhesive used for this bond, etc.

Figures 9 and 10 show very schematically a device 1 c, which differs from the device 1 essentially in that the receiving position 1 1 c and the bond position 15c with respect to the vertical axis of rotation of the turntable 7 are provided diametrically opposite each other that instead of the Components 2 supplied in a belted form are processed from a wafer 38 by separating chips 38 or are bonded to the substrates 4 moved past the bonding position 15, and that instead of the vision system 20, the vision system 23 is deposited at the bonding position 15c the chips 38 on the substrates 4 and the like there Bonding monitors and controls the intended pick-up element in the required manner. In order to process the chips formed by the wafer 37 one after the other, the wafer 37 is arranged at the receiving position 11 c on an XY table, which is controlled by the vision system 22 there in the required manner such that exactly one chip 38 is always present in the middle of the pick-up element.

Figures 9 and 10 show the above two phases of a work cycle, i.e. FIG. 9 shows the phase for picking up a chip 38 at the pick-up position 11 c and placing a chip 38 on a substrate 4 at the bond position 15 c, and FIG. 10 shows the placing of a chip 38 at the pick-up position 11 c in a nest 10 a holder 9 or the removal of a chip 38 from a nest 10 at the bond position 15c.

While FIGS. 9 and 10 thus show a wafer / substrate bonder, FIG. 1 1 shows, as a further possible embodiment, a device 1 d which is designed similarly to device 1 c, but as a wafer / wafer bonder in which the chips 38 of the wafer 37 at the receiving position 11d are each placed on chips 38 of a wafer 40 at the bonding position 15d and bonded in an exact position. In this embodiment, the wafer 40 is also located on an XY table, which is precisely controlled by the vision system 23, the pick-up element present at the bond position 15d preferably also making an adjustment movement in the X-axis and Y- Axis executes, if necessary also an adjustment rotary movement about the Z axis. The adjustment movements and also the movements of the X-Y table for the wafer 40 are controlled by the vision system 22 or 23.

The invention has been described above using various exemplary embodiments. It goes without saying that numerous changes and modifications are possible without departing from the concept on which the invention is based. For example, instead of the described pick-up elements, other suitable tools can also be used, which are then designed, for example, as gripping tongs, vacuum holders etc.

Furthermore, instead of the active adjustment method described in FIG. 8, in which the laser beam 6 ′ of the laser diode 6 already mounted on the substrate 4 is monitored via the vision system 20, other measures for the active adjustment of the component 31 can also be used, for example optically effective structures or surfaces on the component which, when the component 1 is positioned differently, bring about a different view of the laser beam supplied by the laser diode 6, etc.

LIST OF REFERENCE NUMBERS

, 1 a, 1 b, 1 c, 1 d device

Component, 3b assembly

substratum

spacer

Laser diode 'laser beam

turntable

Turntable stepper drive

holder

Nest 1, 1 1 c, 11d pick-up or pick-up position 2 belt 3 pick-up element 4 drive 5, 15a, 15b, 15c, 15d bond position 6 pick-up for assemblies 7 transporter 8, 18a, 18b pick-up element 9 Pick-up head 0 Vision system 1 Edge or reference point 2, 23 Vision system 4 Magazine 5 Tool holder 6 Rotary bearing 27 holding arm

28 force sensor

29 opening

30 laser beam

31 component

32 spacers

33 mirror surface

34 lens

35 contact

36 laser beam

37 wafers

38 chip

39 chip

40 wafers

Claims

claims

1 . Bonder for components (2, 6, 31, 38) with small dimensions with a transfer device (7, 13, 18, 18a, 18b) for transferring the components (2) from a pick-up or pick-up position (1 1, 11 c, 1 1 d)) to a component (3, 3b, 4, 39) available at a bond position (15, 15a, 15b, 15c, 15d) as well as for precise positioning and bonding on this component, characterized in that the transfer device of a transport element (7) driven in a clocked manner in a transport direction (A) and with receptacles (10) for the components (2, 6, 31, 38) which follow one another in the transport direction (A) and of pick-up elements (13, 18, 18a, 18b) at the receiving position (1 1, 1 1 c, 1 1 d) and at the bonding position (15, 15a, 1 5b, 15c, 15d) is formed between the receptacles (10) for the components (2, 6, 31, 38) openings are provided on the transport element (7), and that at least one pick-up element (13, 18, 18a, 18b) in an axial direction (Z axis) perpendicular to the Direction of conveyance (A) between a starting position on one side of the movement path of the receptacles (10) for the components (2, 6, 31, 38) into the receiving position (1 1, 1 1 c, 1 1 d) or bond position (15, 15a , 15b, 1 5c, 15d) on the opposite side of the movement path of the receptacles (10) for the components (2, 6, 31, 38) and also on the receptacles (10) for the components (2, 6, 31, 38 ) can be moved up.

2. Bonder according to claim 1, characterized in that the at least one pick-up element (13) can only be moved in one axial direction (Z axis).

3. Bonder according to claim 1 or 2, characterized in that the one axial direction (Z axis) is the vertical axis.

4. Bonder according to one of the preceding claims, characterized in that the transport element is a rotating plate (7) driven in a clocked manner about an axis parallel to the one axial direction (Z axis).

5. Bonder according to one of the preceding claims, characterized in that the receptacles (10) for the components (2, 6, 31, 38) are provided on an edge of the transport element (7), and that the transport element in the transport direction (A) has an opening or a recess between two receptacles (9, 10) for the components (2, 6, 31, 38).

6. Bonder according to one of the preceding claims, characterized in that the receptacles (10) for the components (2, 6, 31, 38) on protrusions or holders (9) projecting over an edge of the transport element (7) are formed.

7. Bonder according to one of the preceding claims, characterized in that at least one pick-up element (18) by a drive (18) for fine adjustment in at least one further axial direction (X-axis, Y-axis) which is perpendicular to the first axis direction (Z axis), can be moved in a controlled manner and / or can be pivoted about the first axis direction (Z axis).

8. Bonder according to claim 7, characterized in that the at least one further axial direction (X axis, Y axis) is a horizontal axis.

9. Bonder according to one of the preceding claims, characterized by at least one vision system (20, 23) at the bond position (15, 15a, 15b, 15c, 15d) for controlling the pick-up element (18) there and / or a support for the further component or the further assembly (3, 4, 39, 40).

10. Bonder according to one of the preceding claims, characterized by at least one vision system (22) at the receiving position (1 1, 1 1 c, 1 1d) for monitoring and / or controlling the pick-up element (13) there and / or a support or feeder for the first components (2, 6, 31, 38).

1 1 .Bonder according to one of the preceding claims, characterized in that the receiving position (1 1, 1 1 c, 1 1 d) is provided below the path of movement of the component receptacles (10).

12. Bonder according to one of the preceding claims, characterized in that the bonding position (15, 15a, 15b, 1 5c, 15d) is provided below the movement path of the component receptacles (10).

13. Bonder according to one of the preceding claims, characterized in that the pick-up elements (13, 18, 18a, 18b) are pliers or vacuum grippers.

14. Bonder according to one of the preceding claims, characterized in that the pick-up elements (13, 18, 18a, 18b) are designed such that the vision system (20, 22, 23) both the respective component (2nd , 6, 31, 38) and the surroundings (12, 38) from which the component is removed.

15. Bonder according to one of the preceding claims, characterized in that the pick-up elements (13, 18, 18a, 18b) are designed such that the vision system (20, 22, 23) both the respective component (2nd , 6, 31, 38) and the component (3, 3b, 4, 39) on which the component (2, 6, 31, 38) is placed.

16. Bonder according to one of the preceding claims, characterized in that the vision system at the bond position (15, 15a, 15b, 15c 15d) Orientation elements, for example orientation points or edges (21), and the first component (2, 6, 38) are aligned with these markings (21).

1 7.Bonder according to one of the preceding claims, characterized in that when assembling optical components with the help of the vision system (20) there is an active alignment of the component (31) with respect to the component (3) in that with the vision system (20) is detected at least one light beam (6 ') generated by component (3) and entering the component (31).

18. Bonder according to one of the preceding claims, characterized in that the bonding of the respective component (2, 6, 31, 38) on the component (3, 3b, 4, 39) by laser bonding, for example by laser soldering or -welding, or by gluing.