JP2014179561A - Bonding head and die bonder equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bonding head and a die bonder which make it possible to correctly recognize, from above, a shape and a posture of a sucked die without being restricted by the installation position of a camera.SOLUTION: A bonding head comprises: a shank into which a vacuum is introduced; a collet arranged at a tip end of the shank and having an opening at its tip; an optical fiber whose end is inserted and airtightly fixed inside the shank; and a camera part arranged at the other end of the optical fiber. An image is formed when incident light from the opening of the collet is propagated by the optical fiber, and the camera part picks up the image thus formed. Further, the bonding head is applied to a bonding head or a pickup head constituting a die bonder.

Description

  The present invention relates to a die bonder for mounting a semiconductor chip or the like on a substrate, and more particularly to a bonding head for such a die bonder.

  As part of the process of assembling a package by mounting a die (semiconductor chip) (hereinafter simply referred to as “die”) on a substrate such as a wiring board or lead frame, the die is removed from a semiconductor wafer (hereinafter simply referred to as “wafer”). There are a division step and a bonding step in which the divided dies are mounted on a substrate or stacked on a die that has already been bonded. In a bonding process in which a die is mounted on or stacked on a substrate, a bonding head that sucks the die at its tip by vacuum is generally used.

  According to the following Patent Document 1, a bonding head in which an optical fiber cable is provided on a part of a shaft constituting the bonding head and light irradiation is performed by a chip adsorbing member of the bonding head is already known. Further, according to the following Patent Document 2, an optical fiber cable for guiding light from a light emitting element is provided on a part of a collet that adsorbs a chip to its tip, and the chip is provided on the collet via the optical fiber. Despite the downsizing of the suction hole due to the downsizing of the chip by reliably guiding it to the suction hole, it is possible to erroneously judge the chip pickup by projecting light through the suction hole without fail. A chip adsorbing structure to prevent is already known.

Japanese Patent No. 3520702 JP 2006-332395 A

  By the way, in order to bond the die accurately on the substrate, in the step of bonding the divided dies on the substrate or the like, the die is bonded to the bonding head on the intermediate mounting table, for example. It is necessary to adsorb so as to be in a position. Therefore, conventionally, a camera for recognizing a die attracted to the head is generally provided, and the position / orientation of the die attracted to the tip of the bonding head is corrected based on the imaging data. It was. As a result, the price of the device increases.

  Also, when installing such a camera, it is difficult to focus on a large die, especially when the camera is placed at a position where the camera is recognized obliquely with respect to the die due to restrictions on the installation location. The shape / posture cannot be accurately recognized. In general, in order to accurately recognize the shape and posture of the die, it is preferable to install a camera below the die. However, in an actual die bonder, it may actually be difficult to install a camera below the apparatus due to the positional relationship with other apparatuses. Alternatively, it is possible to install a camera above the die, but in this case, the bonding head with the die adsorbed on its tip must be rotated so that the die shape cannot be recognized by the camera. However, there are problems such as an increase in work steps and a reduction in throughput.

  Therefore, the present invention has been made in view of the above-described problems in the prior art, and its purpose is not limited by the installation location of the camera, and the shape and orientation of the die adsorbed to the tip of the head. An object of the present invention is to provide a bonding head that enables accurate recognition from above and a die bonder including the head.

  In order to achieve the above object, first, according to the present invention, a shank into which a vacuum is guided, a collet provided at the tip of the shank and having an opening at the tip, and a tip within the shank. A bonding head comprising an optical fiber inserted and fixed in an airtight manner and a camera unit provided at the other end of the optical fiber, and incident light from the opening of the collet is propagated by the optical fiber to form an image. The camera unit is provided with a bonding head that captures the formed image.

  According to the present invention, in the bonding head described above, the optical fiber preferably includes an imaging optical system at a tip thereof, and for guiding illumination light in parallel with the optical fiber. It is preferable that an optical fiber is provided, and further that the camera unit further includes a light source for supplying illumination light to the optical fiber for guiding the illumination light.

  According to the present invention, in order to achieve the above object as well, a die supply unit that holds a wafer in a part and includes a pickup head that picks up a die from the wafer, and supplies the picked-up die, An intermediate stage for mounting a die supplied from the die supply unit by a pickup head, a substrate transfer pallet for mounting a substrate on which the die is mounted and transferring it to a bonding position, and picking up the die from the intermediate stage In the die bonder having a bonding head for bonding the die to the upper surface of the substrate on the substrate transfer pallet or the die already bonded to the substrate, the bonding head or the pickup head Is formed by the bonding head described above. It has been that the die bonder is provided.

  According to the above-described present invention, the bonding head that can accurately recognize the shape and posture of the die attracted to the tip of the head from above without being limited by the installation location of the camera. Thus, an excellent effect is provided that a die bonder including the head and having excellent bonding performance and capable of being manufactured at a lower cost is provided.

It is a top view which shows an example of schematic structure of the die bonder which becomes one embodiment of this invention. It is a side view which shows the operation | movement with the structure of the die bonder of the said invention. It is a perspective view including the bonding head which becomes Example 1 of this invention. It is a partial expanded sectional view of the said bonding head. It is a figure which shows the structure of the camera containing the optical fiber which comprises the said bonding head. It is a figure which shows an example of the image of the die | dye obtained by the said bonding head. It is a figure which shows the structure of the camera part containing the optical fiber in the bonding head which becomes Example 2 of this invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  First, FIG. 1 is a top view showing a schematic configuration of a die bonder according to an embodiment of the present invention. That is, the die bonder is roughly divided into a die supply unit 1 that supplies a die D to be mounted on the substrate P, a pickup unit 2 that picks up a die from the die supply unit 1, and a picked-up die D in an intermediate manner. An alignment unit 3 for mounting, and a bonding unit for picking up a die D mounted on the mounting table and bonding it on the substrate P or on a die already bonded on the substrate. 4, a transport unit 5 that transports the substrate P to the mounting position, a substrate supply unit 6 that supplies the substrate P to the transport unit 5, a substrate carry-out unit 7 that receives the substrate 6 that has been mounted, and the above-described A control unit 8 that monitors and controls the operation of each unit is provided.

  Next, details and operations of each part of the die bonder whose schematic configuration has been described above will be described in detail with reference to FIG. 2 in addition to FIG. FIG. 2 is a diagram for explaining the configuration and operation showing the features of the present embodiment as viewed from the direction of arrow A in FIG.

  First, the die supply unit 1 includes a wafer holding table 12 that holds the wafer 11 and a push-up unit 13 (shown by a dotted line) that pushes up the die D from the wafer 11. The die supply unit 1 is moved in the X and Y directions by a driving unit (not shown), thereby moving the die D to be picked up to the position of the push-up unit 13.

  The pickup unit 2 has a collet that sucks and holds the die D pushed up by the push-up unit 13 at the tip, and further, a pickup head 21 for placing the picked up die D on the alignment unit 3; And it has the Y drive part 23 of the pick-up head for moving the said pick-up head 21 to a Y direction (refer the arrow of FIG. 1). Note that the pickup head 21 includes a drive unit that moves the collet up and down, rotates, and moves in the X direction, although not shown here.

  The alignment unit 3 recognizes the die D on the intermediate stage 31 and the electronic component placement table (hereinafter referred to as “intermediate stage”) 31 for temporarily placing the die D on the upper surface thereof. And a stage recognition camera 32. At this time, in order for the stage recognition camera 32 to reliably recognize the die D on the intermediate table 31, the die D is placed on the upper surface of the intermediate table in a state where it is not curved (so-called warpage) or inclined. Need to be done.

  The bonding unit 4 has the same structure as the pickup head described above. That is, the die D is picked up from the intermediate stage 31 and bonded to the transported substrate P, the bonding head 41 for moving the bonding head 41 in the Y direction, and the transported substrate P. And a substrate recognition camera 44 for recognizing the bonding position of the die D to be bonded. With such a configuration, the bonding head 41 corrects the pickup position / orientation based on the imaging data of the stage recognition camera 32, picks up the die D from the intermediate stage 31, and based on the imaging data of the substrate recognition camera 44, A die D is bonded on the substrate P.

  The transport unit 5 includes a substrate transport pallet 51 on which one or a plurality of substrates P (four in FIG. 1) are placed, and a pallet rail 52 on which the substrate transport pallet 51 moves. And the first and second transport units having the same structure provided in parallel. The substrate transport pallet 51 is moved by driving a nut (not shown) provided on the substrate transport pallet with a ball screw (not shown) provided along the pallet rail 52.

  According to the die bonder having such a configuration, the substrate transport pallet 51 is placed on the substrate supply unit 6, moves to the bonding position along the pallet rail 52, and moves to the substrate carry-out unit 7 after the bonding is completed. To do. Then, the substrate for which bonding is completed is transferred to the substrate carry-out unit 7. The first and second transfer units are driven independently of each other. As a result, while the die D is being bonded to the substrate P placed on one substrate transfer pallet 51, the other substrate transfer pallet 51 is connected to the substrate P. Is returned to the substrate supply unit 6 to prepare for placing a new substrate.

  Next, details of the bonding head 41 in the die bonder having the above-described configuration will be described with reference to FIGS. 3 is a perspective view of a part including the bonding head 41, FIG. 4 is a partially enlarged sectional view of the bonding head 41, and FIG. 5 is a configuration of a camera including an optical fiber constituting the bonding head 41. FIG.

  As shown in FIG. 3, a vacuum pump unit 414 is connected to a part of the shank 411 constituting the bonding head 41 via a pipe 412 and a valve 413, and the vacuum by the vacuum pump unit is inside the shank 411. Led to. Also, one end of an optical fiber 501 constituting the camera unit 50 described in detail below is inserted from the upper end of the shank 411 into the inside thereof. Note that the optical fiber 501 is attached to the shank 411 so as to be airtight at the upper end of the shank 411. The other end of the optical fiber 501 is attached with, for example, an optical system for forming an optical image with light from the optical fiber and a camera main body 52 including an image sensor such as a CCD. Further, in this figure, a state is shown in which a die D to be bonded onto the substrate P is mounted on the intermediate stage 31 and the bonding head 41 is positioned above the die D.

  As shown in FIG. 4, a so-called collet 415 made of an elastic body such as rubber is attached to the tip of the shank 411 constituting the bonding head 41. The collet 415 has a suction hole 416 formed in a part thereof, and the tip of the collet 415 comes into contact with the surface of the die D mounted on the intermediate stage 31, so that the suction hole 416 is interposed. Then, the die D is adsorbed to the tip by vacuum. As apparent from the figure, the optical fiber 501 inserted from the upper end of the shank 411 is mounted on the intermediate stage 31 through the suction hole 416 formed at a part of the collet 415 at the tip. It is arranged so as to face the die D.

  A specific example of the optical fiber 501 described above is shown in FIG. That is, an optical fiber bundle 512 composed of a plurality of optical fibers is inserted inside a sheath (outer coating) 511 that forms the outer periphery of the optical fiber 501, and a spherical lens 513 such as a convex lens is provided at the tip thereof. It is attached as an imaging optical system. According to such a configuration, the light incident from the distal end portion of the optical fiber 501 forms an image on the distal end portion of the optical fiber bundle 512, and the light is propagated to the other end face via the optical fiber bundle 512. The light propagated to the other end face of the optical fiber bundle 512 further forms an image of an image sensor such as a CCD via a spherical lens (imaging optical system) such as a convex lens that constitutes the camera body 52. It forms an image on the surface and can be imaged by the image sensor. That is, the die D mounted on the intermediate stage 31 can be imaged from above through the suction hole 416 formed in a part of the collet 415. Reference numeral 514 in this figure is a transparent liquid member filled in a gap between the spherical lens 513 and the tip of the optical fiber bundle 512, and optical coupling between these lenses and the fiber bundle is achieved. Therefore, it is preferable to use a member having a refractive index substantially equal to those.

  Furthermore, FIG. 6 attached shows an example of an image of the die D on the intermediate stage 31 when the image is picked up by the optical fiber 501 through the suction hole 416 at the tip of the collet 415 using the bonding head 41 described above. 6A shows a state in which the die D is located directly below (correct position) with respect to the collet 415, and FIG. 6B shows that the die D has slightly deviated from the collet 415 (ie, , Each of which shows a position slightly shifted in the vertical and horizontal directions and slightly rotated). Thus, by using the bonding head 41 according to the present invention, the entire die D mounted on the intermediate stage 31 is imaged from directly above where the bonding head 41 that picks up the die D is located. Can be done. That is, the position of the die D with respect to the collet 415 (that is, the suction position of the die D) can be easily detected with a captured image from directly above, compared to a conventional captured image from an oblique direction. It becomes possible.

  When the size of the die D is relatively large, the bonding head 41 including the collet 415 is positioned away from the die D (directly above) as is apparent from FIG. By disposing in this manner, the entire die D can be imaged as described above. That is, the shape / posture of the die adsorbed to the tip of the head can be changed from above without being limited by the installation location of the camera (that is, the camera is disposed obliquely to avoid the position of the bonding head 41). It is possible to provide a bonding head that enables accurate recognition and a die bonder including the head. In this case, the stage recognition camera 32 described above can be omitted, leading to a reduction in the manufacturing cost of the die bonder device.

  Subsequently, FIG. 7 attached is a view showing a characteristic part of a bonding head 41, particularly a camera including the optical fiber, according to another embodiment (embodiment 2) of the present invention. That is, in the second embodiment, in addition to the above-described optical fiber for light reception, an optical fiber for illumination is further provided in parallel. More specifically, as shown in the figure, the camera body 52 is provided with a light emission source 521 such as a light emitting diode or an incandescent bulb, and a sheath (outer coating) constituting the optical fiber 501. ) In addition to the lens 513 that is the optical system of the incident light and the optical fiber bundle 512 that is the propagation path, the light from the light emitting source 521 is irradiated to the die D picked up by the bonding head 41 inside 511. An optical fiber bundle 515 for propagating illumination light and a spherical lens (in this example, a concave lens) 516 constituting an optical system therefor are integrally configured. Reference numeral 516 in this figure is also a transparent liquid member filled in a gap between the lens 515 and the tip of the optical fiber bundle 515, like the liquid member 514 described above, and these lens and fiber bundle. In order to achieve optical coupling between them, it is preferable to use a member having a refractive index substantially equal to them.

  That is, according to the bonding head 41 according to the above-described embodiment (embodiment 2), the die D mounted on the intermediate stage 31 is imaged from directly above and further irradiated with illumination light from above. Therefore, even when there is not enough illumination light, the shape / posture of the die adsorbed to the tip of the head can be adjusted without being restricted by the camera installation location, as in the first embodiment. It is possible to provide a bonding head that enables accurate recognition from above and a die bonder including the head.

  In the above, the present invention has been described in detail with respect to an example in which the present invention is applied to a bonding head of a die bonder. However, the present invention is not limited to this, and for example, a pickup head that is another element constituting a die bonder. It is also possible to apply to 21. Even in that case, those skilled in the art will easily understand that the pickup head 21 is configured in the same manner as described above, and that the same effect as described above can be obtained.

  In the above, the embodiments of the present invention have been described. However, various alternatives, modifications, and variations can be made by those skilled in the art based on the above description, and the present invention is described above without departing from the scope of the present invention. Various alternatives, modifications or variations are encompassed.

  DESCRIPTION OF SYMBOLS 1 ... Die supply part 10, 10A ... Die bonder, 11 ... Wafer, 12 ... Wafer holding stand, 13 ... Push-up unit, 14 ... Wafer holding stage, 2 ... Pick-up part, 21 ... Pick-up head, 3 ... Alignment part, 31 ... Mounting table (intermediate stage), 411 ... Shank, 414 ... Vacuum pump part, 415 ... Collet, 50 ... Camera part, 501 ... Optical fiber, 511 ... Sheath (outer coating), 512 ... Optical fiber bundle, 513 ... Lens, 52 ... Camera body part, 5 ... conveying part, 6 ... substrate supply part, 7 ... substrate unloading part, 8 ... control part, D ... die, P ... substrate.

Claims (6)

A shank with a vacuum inside,
A collet provided at the tip of the shank and having an opening at the tip;
An optical fiber that is hermetically fixed by inserting a tip inside the shank;
A bonding head provided with the camera unit provided at the other end of the optical fiber,
A bonding head, wherein incident light from an opening of the collet is propagated by the optical fiber to form an image, and the camera unit picks up the formed image.   The bonding head according to claim 1, wherein the optical fiber includes an imaging optical system at a tip thereof.   3. The bonding head according to claim 2, further comprising an optical fiber for guiding illumination light in parallel with the optical fiber.   4. The bonding head according to claim 3, wherein the camera unit further includes a light source for supplying illumination light to an optical fiber for guiding the illumination light. A die supply unit that holds a wafer in a part and includes a pickup head that picks up a die from the wafer, and supplies the picked-up die;
An intermediate stage for mounting a die supplied from the die supply unit by the pickup head;
A substrate transport pallet for mounting the substrate on which the die is mounted and transporting the substrate to a bonding position;
In the die bonder that picks up the die from the intermediate stage and includes a bonding head for bonding the die to the substrate on the substrate transport pallet or the upper surface of the die that is already bonded on the substrate.
The said bond head is comprised by the bonding head as described in any one of the said Claims 1-4, The die bonder characterized by the above-mentioned. A die supply unit that holds a wafer in a part and includes a pickup head that picks up a die from the wafer, and supplies the picked-up die;
An intermediate stage for mounting a die supplied from the die supply unit by the pickup head;
A substrate transport pallet for mounting the substrate on which the die is mounted and transporting the substrate to a bonding position;
In the die bonder that picks up the die from the intermediate stage and includes a bonding head for bonding the die to the substrate on the substrate transport pallet or the upper surface of the die that is already bonded on the substrate.
The die bonder, wherein the pickup head is constituted by the bonding head according to any one of claims 1 to 4.

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