JP2013157530A - Die bonder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a die bonder which improves reliability with high throughput by excluding a moving operation of a camera for recognition for imaging adhesive application.SOLUTION: A die bonder comprises a die packaged on a lead frame 35, a syringe 34a which is positioned in an upper part of the die and in which a paste-state adhesive is sealed, a first camera 33a for recognition which is fixed in the vicinity of the syringe 34a, and a second camera 33b for recognition which is provided at a downstream side of the first camera 33a for recognition. The first camera 33a for recognition images a surface of the lead frame 35 before applying the adhesive 36 thereto, and the second camera 33b for recognition images an appearance of the applied adhesive 36.

Description

  The present invention relates to a die bonder.

  A die bonder is a device that bonds a die (a chip of a silicon substrate on which an electronic circuit is built) to a lead frame, a substrate, or the like using solder, gold plating, or resin as a bonding material. An engineering plastic is used as a die bonding material (paste, film) for bonding the die and the substrate, and the die is positioned and bonded to a lead frame, a substrate, or the like. At present, a method of bonding using resin as a bonding material has become the mainstream.

  In semiconductor die bonding, solder and die bonding resin paste (Ag epoxy and Ag polyimide) are used as adhesives to fix semiconductor chips (IC, LSI) to lead frames, ceramic cases, substrates, etc. .

JP 2001-127080 A JP 2004-288715 A

  Now, an adhesive for adhering the die to a lead frame or the like is enclosed in a syringe. The syringe moves up and down with respect to the lead frame to inject and apply a paste adhesive. That is, a predetermined amount of adhesive is applied to a predetermined position by a syringe in which a paste-like adhesive is sealed, and a die is pressure-bonded and bonded onto the adhesive.

  At that time, it is necessary to check with a recognition camera whether there is a problem on the surface of the lead frame to which the paste adhesive is applied before bonding. Therefore, conventionally, the recognition camera is moved to the shooting position and shot, and the bonding operation is performed after an appropriate bonding position is detected. After the bonding, the recognition camera moves again to the shooting position, and shooting is performed to check whether the paste adhesive is properly applied.

  As described above, in the conventional die bonder, each time the paste adhesive is applied to the lead frame, one recognizing camera moves twice to the photographing position to photograph, and there is a very wasteful process. That is, the conventional die bonder includes an inefficient movement in which the processing capacity (throughput) per unit time is reduced.

  On the other hand, Patent Documents 1 and 2 are provided with a recognition camera and illumination for image recognition, but are not considered to increase the throughput of the operation of applying the adhesive.

  It is an object of the present invention to eliminate a moving operation of a recognition camera for photographing an adhesive application and provide a highly reliable die bonder with high throughput.

  To achieve the above object, the present invention is attached to a syringe for applying an adhesive on a lead frame, a bonding head for mounting a die on the applied adhesive, and the vicinity of the syringe. A first recognition camera; and a second recognition camera provided downstream of the first recognition camera, the first recognition camera being a surface of the lead frame before application of adhesive The second recognition camera is configured to photograph the appearance of the die mounted on the applied adhesive.

  In order to achieve the above object, the present invention preferably provides a first illumination in the vicinity of the first recognition camera and a second illumination in the vicinity of the second recognition camera.

  In order to achieve the above object, the present invention is preferably configured such that each of the first and second illuminations is a set, and the two illuminations are arranged in a substantially square shape.

  In order to achieve the above object, the present invention is preferably configured such that the first and second illuminations are composed of a plurality of LEDs.

  In order to achieve the above object, the present invention is preferably configured such that the first recognition camera detects the viscosity of the adhesive dropped from the syringe and performs a curing operation by blowing according to the detected viscosity. It is good to have.

  ADVANTAGE OF THE INVENTION According to this invention, the movement operation | movement of the camera for recognition for imaging | photography of adhesive agent application is excluded, and the reliable die bonder by high throughput can be provided.

It is the conceptual diagram which looked at the die bonder which concerns on Example 1 of this invention from the top. It is an external appearance perspective view of the preform part which concerns on Example 1 of this invention. It is a schematic block diagram of the preform part which concerns on Example 1 of this invention. It is a schematic block diagram of the preform part which concerns on Example 2 of this invention. It is a front view of the illuminating device which concerns on Example 2 of this invention. It is a flowchart which shows operation | movement of the Example which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a conceptual diagram of a die bonder according to a first embodiment of the present invention as viewed from above.
In FIG. 1, the die bonder can be roughly divided into a wafer supply unit 1, a frame supply / conveyance unit 2, and a die bonding unit 3.
The frame supply / conveyance unit 2 includes a stack loader 21, a main feeder 22, and an unloader feeder 23. A frame (hereinafter referred to as a lead frame) supplied to the main feeder 22 by the stack loader 21 is conveyed to the unloader 24 through two processing positions on the main feeder 22. The stack loader 21, the main feeder 22, and the unloader feeder 23 travel on the two traveling lanes 20 and convey the lead frame.

  The die bonding unit 3 includes a preform unit 31 and a bonding head unit 32. A preform part 31 which is a pre-process of the die bonding part 3 is a part for applying a die adhesive (hereinafter referred to as a paste adhesive) to the lead frame conveyed by the main feeder 22. The bonding head unit 32 picks up and lifts the lead frame coated with the paste adhesive from the pickup device 12 and moves the die to the bonding point on the main feeder 22 in parallel. Then, the bonding head unit 32 lowers the die and performs bonding on the lead frame to which the paste adhesive is applied.

  A recognition camera described later is attached in the vicinity of the preform portion 31. This is to check whether a predetermined amount of the paste adhesive applied by the recognition camera is applied to a predetermined position. As will be described later, a syringe that moves up and down is provided on the upper portion of the preform portion 31. A paste-like adhesive is sealed inside the thin ring, and the paste-like adhesive is ejected from the nozzle tip by air pressure. This syringe will alternately apply the paste adhesive to the lead frame conveyed on the two traveling lanes 20.

  The wafer supply unit 1 includes a wafer cassette lifter 11 and a pickup device 12. The wafer cassette lifter 11 has a wafer cassette (not shown) filled with wafer rings, and sequentially supplies the wafer rings to the pickup device 12.

  Incidentally, the die bonder shown in FIG. 1 is configured such that the preform portion 31 and the bonding head portion 32 operate with respect to the lead frame traveling on the two traveling lanes 20. The paste adhesive application process in that case will be briefly described.

  First, the position on the lead frame is confirmed by a recognition camera, and if there is no problem on the surface to be coated, the coating operation is performed. After bonding the die to the applied paste adhesive, the same recognition camera was operated to check whether there was any problem in the bonding state. In other words, the die bonding is performed by reciprocating one recognition camera twice.

  Therefore, the lead frame traveling (X direction) speed must be set in accordance with the two reciprocating motions of the recognition camera, which limits the speeding up of bonding.

  By the way, in recent years, die bonders with several kinds of variations have been set in order to respond to user requests. For example, as described in the description of FIG. 1, the adhesive is applied with one syringe to two rows of lead frames traveling on two traveling lanes 20. Alternatively, it can be applied to two rows of lead frames with two syringes. Alternatively, the lead frame on one traveling lane 20 may be applied with one syringe.

  Therefore, the inventors of the present invention mount a recognition camera in the space and remove two syringes from the model that had two syringes attached, in view of vacant space and improved throughput. It is intended to achieve high throughput by performing appearance inspection with a camera.

Hereinafter, the details of the present invention will be described with reference to the drawings.
FIG. 2 is an external perspective view of the preform portion according to the first embodiment of the present invention.
FIG. 3 is a schematic perspective view of the preform portion according to the first embodiment of the present invention.
2 and 3, a syringe 34a is attached to the left side of the drawing. A paste adhesive 36 is sealed inside the syringe 34a. Although 34b is also a syringe, what was originally attached is removed as shown by the dotted line in this figure. A first recognition camera 33a is attached to the rear of the syringe 34a. The syringe 34b is removed and a second recognition camera 33b is attached to the empty space. Illuminations 38a to 38d are attached below the respective recognition cameras 33a and 33b.

  The lead frame 35 is conveyed below the syringe 34a. On the surface of the lead frame 35, a paste adhesive 36 applied by a syringe 34 a and a die 37 is mounted on the paste adhesive 36. The die 37 moves in the arrow X direction together with the lead frame 35.

  The recognition camera 33a is tilted and fixed so as to always aim at the application surface of the paste adhesive 36. The recognition camera 33b is fixed so as to be inclined so as to always aim at the applied paste adhesive 36. The illuminations 38a to 38b are composed of a plurality of LEDs. The lights 38a and 38c are the first lights, and the lights 38b and 38d are the second lights. In the first illumination, the illuminations 38a and 38c are arranged in a substantially square shape so that the adhesive application surface is illuminated by a pinpoint, and the illuminations 38b and 38d are also arranged in a substantially square shape in the second illumination. These lights always illuminate the application surface of the paste adhesive 36 and the applied paste adhesive 36 in the same manner as the first and second recognition cameras 33a and 33b.

The preform portion 31 as described above operates as follows to apply the paste adhesive 36.
That is, the lead frame 35 moves from the arrow X direction. When the lead frame 35 comes directly under the syringe 34a, it is stopped, and it is confirmed from the image taken by the fixed first recognition camera 33a whether the application surface of the paste adhesive 36 is appropriate. When it is confirmed that there is no problem on the application surface, the syringe 34a is lowered and the paste adhesive 36 is applied at a predetermined position. When the application of the paste adhesive 36 by the syringe 34a is completed and the syringe 34a is lifted, the lead frame 35 moves to the position of the second recognition camera 33b, and the paste adhesive 36 is moved by the second recognition camera 33b. Check the appearance such as whether the amount is appropriate or whether there is liquid dripping. When it is confirmed that there is no dripping at an appropriate amount, the process proceeds to the next coating operation. If there is no problem in application of the paste adhesive 36, the die 37 is pressure-bonded onto the adhesive and bonded.

FIG. 4 is an enlarged view of the preform portion as viewed from the side.
In FIG. 4, at the stage where the syringe 34a is raised, the part to which the paste adhesive is to be applied is photographed by the first recognition camera 33a. As a result of photographing, when it is determined that there is no problem in application, the syringe 34a descends and the paste adhesive 36 is applied. Thereafter, the lead frame 35 moves to the position of the second recognition camera 33b. After the movement, the second recognition camera 33b photographs the appearance of the applied paste adhesive 36. If it is determined that there is no problem as a result of photographing, the process moves to a die bonding process. This process is repeated.

  As described above, the illuminations 38a to 38d are composed of a plurality of LEDs, and two are a set. The illuminations 38a to 38b are attached to the first and second recognition cameras 33a and 33b, respectively, and the manner of merging is substantially letter-shaped so that the photographing point can be illuminated intensively. ing.

  As described above, in this embodiment, the appearance inspection of the application surface of the paste adhesive 36 and the appearance inspection of the paste adhesive 36 after application can be respectively photographed with dedicated cameras. Accordingly, the recognition camera does not move, and the adhesive application operation can be performed with high throughput.

FIG. 5 is a schematic configuration diagram of a preform portion according to the second embodiment of the present invention.
In FIG. 5, the viscosity of the paste-like adhesive 36 may be lowered due to the blending balance or temperature / humidity relationship. In that case, as shown in FIG. 5, the paste-like adhesive 36 dripped on the coated surface of the lead frame 35 and not only contaminates the coated surface, but also has a great influence on the die adhesion. There is sex.

  On the other hand, in the present embodiment, the first recognition camera 33a can observe the dropping of the paste adhesive 36 in advance. Therefore, it is possible to quickly cope with replacement of the paste adhesive 36 and the like. Or when dripping of an adhesive agent is confirmed, it is also possible to add control which applies a cold wind to a syringe and raises a viscosity.

  As described above, according to the present embodiment, since the poor viscosity of the paste adhesive 36 can be observed in advance, it is possible to prevent the subsequent die adhesion failure.

FIG. 6 is a flowchart showing the operation of the embodiment according to the present invention.
In FIG.
(Step 101): The lead frame is transported to a predetermined position in the preform part, and preparations for applying the paste adhesive are started.
(Step 102): The first recognition camera is used to photograph whether the lead frame that has been conveyed has a problem with the paste adhesive applied surface at a predetermined position.
(Step 103): When it is confirmed that there is no problem on the paste adhesive application surface of the lead frame, the adhesive application operation is continued. On the other hand, if it is confirmed that there is a problem on the coating surface, the coating operation is stopped as an error (step 104).

(Step 105): When it is confirmed that there is no problem on the application surface, the syringe descends and a predetermined amount of paste adhesive is applied onto the lead frame.
(Step 106): When the syringe to which the paste adhesive has been applied rises, the appearance of the paste adhesive to which the second recognition camera is applied is confirmed.
(Step 107): When the amount of the paste adhesive is small or rubbing is confirmed, the operation is stopped as an application failure error (Step 108). When it is confirmed that there is no problem, the paste adhesive application process is completed.

  As described above, according to this embodiment, since the paste adhesive application operation is always monitored by the first and second recognition cameras, a predetermined amount of paste adhesive can be applied. Even if there is a problem with the application surface of the frame, it is possible to immediately replace the paste adhesive or the frame, thus preventing errors in the application operation.

  As described above, according to the present invention, since the recognition camera does not move, throughput is increased and productivity is improved. In addition, since the tip of the syringe nozzle can be confirmed with the recognition camera, the maintainability of the syringe is improved.

  Furthermore, since it is possible to confirm whether or not the paste adhesive is applied normally and to check the dripping state, the quality can be improved.

  DESCRIPTION OF SYMBOLS 1 ... Wafer supply part, 2 ... Frame supply / conveyance part, 3 ... Die bonding part, 11 ... Wafer cassette lifter, 12 ... Pickup device, 20 ... Travel lane, 21 ... Stack loader, 22 ... Main feeder, 23 ... Unloader feeder , 24 ... Ando, 31 ... Preform part, 32 ... Boarding head part, 33a ... First recognition camera, 33b ... Second recognition camera, 34a, 34b ... Syringe, 35 ... Lead frame, 36 ... Paste Adhesive, 37 ... die, 38 ... illumination, 38a, 38c ... first illumination, 38b, 38d ... second illumination.

Claims (5)

A syringe for applying an adhesive on the lead frame; a bonding head for mounting a die on the applied adhesive; a first recognition camera attached in the vicinity of the syringe; and the first A second recognition camera provided downstream of the recognition camera,
The first recognition camera photographs the surface of the lead frame before applying the adhesive, and the second recognition camera captures the appearance of the die mounted on the applied adhesive. Die bonder featuring. The die bonder according to claim 1, wherein
A die bonder, characterized in that a first illumination is provided in the vicinity of the first recognition camera and a second illumination is provided in the vicinity of the second recognition camera. The die bonder according to claim 2,
A die bonder characterized in that each of the first and second illuminations is a pair, and the two illuminations are arranged in a substantially square shape. The die bonder according to claim 2,
The die bonder characterized in that the first and second illuminations are composed of a plurality of LEDs. The die bonder according to claim 1, wherein
The die bonder according to claim 1, wherein the first recognition camera includes a control unit that detects a viscosity of the adhesive dropped from the syringe and performs a curing operation by blowing air according to the detected viscosity.

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