JPH0312939A - Detection of pick up mistake by mount head - Google Patents

Abstract

PURPOSE:To prevent lowering of yield of a die bonding process by locating an emission-side sensor to a collet and a photosensitive sensor to a member which is movable together with a mount head and by moving the photosensitive sensor following movement of the collet which attracts a semiconductor pellet. CONSTITUTION:An emission-side sensor 4 is provided inside a collet 3. A mechanism to transfer a lead frame is provided with a slider 8 which is slidable along the transfer direction and movable together with a mount, wherein a photosensitive-side sensor 13 is provided. Since the slider 8 is fixed to a lever 5 which is attached to the mount head and located across the transfer mechanism, and has a structure to allow both to move integrally, the photosensitive- side sensor 13 can follow a movement of the collet 3. Thereby, it is possible to improve not only index but also yield of a die bonding process.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a die bonding device used in the assembly process of semiconductor elements, and in particular, to prevent a decrease in yield due to pick-up errors of semiconductor pellets. The present invention relates to a method for detecting pickup errors using a mount head.

(Conventional technology) The assembly process of integrated circuit elements, etc. has been automated earlier than the pre-processing process in which circuits and devices are fabricated on semiconductor wafers, and productivity has improved with the practical use of bonders and die bonding equipment. This has greatly contributed to the improvement of semiconductor pellets, and devices with slightly different structures are used depending on the type of semiconductor pellet to be processed.

In addition to using a glass epoxy substrate, it is common to assemble semiconductor devices using a so-called lead frame. (described as pellets) are die-bonded and inked.

By the way, in the assembly process, semiconductor pellets 1~ are mounted on lead frames (I, ead Frame).
The process is broadly divided into the mounting process, bonding process, resin sealing process, and cut and bend process, but all of these processes are currently automated, and some processes are A device that can operate continuously has also been developed and put into practical use.

Lead frames are known for so-called DIP, ST[), and a combination of both types, and for multi-pin elements such as integrated circuit elements, 1) IP or mixed types are generally used. It's being used.

The semiconductor pellet to be mounted on this lead frame is attached to a film made of organic matter stretched over a metal ring, and the semiconductor pellet is pushed up by a push-up pin installed in the die bonding equipment. The knot is attracted and mounts on the bed formed on the lead frame. In reality, the semiconductor pellets 1 to 1 attached to the organic film are not arranged in an orderly manner and are arranged in a somewhat meandering manner. This is because a semiconductor wafer on which elements and circuits are built is connected to a die sink line (Djc)
Plaid dicer (B) along jng Lj, ne)
] After cutting the semiconductor pellets to the middle of the thickness using a cutting machine, and then stretching the organic film to which this is attached, individual semiconductor pellets are cut into individual semiconductor pellets using a Braking machine.
g) Doing.

Therefore, the semiconductor notches 1 attached to the organic film attached to the metal ring are not arranged in an orderly manner, but are in a somewhat meandering state.

In order to mount such a semiconductor device on the bed of a semiconductor device, a die bonding device as described in Section 2 is used, and its outline will be explained below.

As shown in FIGS. 3a and 3b, the head part 50 attached to the X-stage of the X-Y table has a hollow part (not shown) connected to a decompression mechanism. Semiconductor belen 1 attached to a membrane attached to a metal ring
-52- is suctioned and then mounted on the bed portion of the lead frame using, for example, an adhesive.

This head section 50 is mounted on the X-Y table as described above, but recently, a digital (hereinafter referred to as D/G) head type die bonding device that can vary the speed and torque has been used. , and since it is automated,
Sensors for detecting whether or not the collet 51 securely grips the semiconductor pellet 52 are labeled with mounting numbers.

That is, as is clear from FIG. 3a, a fixed mount position 54 is set in the transport mechanism 53 of the frame including the head part, and the Cholera 1-51 is attached to the shaft stage 55 as shown in FIG.

A light-emitting side sensor 56 is installed in this collet 51 as part of a transmission type sensor, and a corresponding light-receiving side sensor 57 is attached to a fixed holder 58 screwed to the side surface of the transport mechanism 53.

Therefore, the collet 51 equipped with the light-emitting side sensor 56 passes over the light-receiving side sensor 57 to check whether the semiconductor pellet 52 has been sucked and gripped from the pick-up position 59 or not.

(Problem to be solved by the invention) A problem occurred with a die bonder having such a structure.

That is, the mount 1- is formed on the bed portion formed on the lead frame.
Recently, models that require multiple semiconductor pellets have appeared.

In the die bonder in which the mount position 54 is fixed as described in -1-, the positional relationship with one semiconductor pellet 52 is on a straight line as shown in FIG. The semiconductor bellet 52 must be transported to a position slightly deviated from this straight line.

Therefore, the trajectories of the collections 1 to 51 shown in FIGS. 4a and 4b need to be moved in the left-right direction of the paper (in the X direction of the X-axis stage) after passing over the light-receiving side sensor 57.

For this reason, the index (Index) of the D/G mount 1 was decreased from 1 to 1 cycle. That is, in such a pickup error detection method using a mount head, depending on the model, the X of the mount position 54 may be
Since the amount of directional deviation is different, the distance from the light-receiving side sensor 57 to the mounting position 54 is also different, and it is necessary to adjust the movement of the D/G head each time, which has the drawback of lacking versatility for different types.

The present invention has been made in view of the above circumstances, and has four objects, in particular, to enable the light-receiving side sensor to follow the movement of the D/G head.

[Structure of the invention]

(Means for Solving the Problem) A mechanism is provided for transporting the semiconductor pellet from the mount 1 to the slide 1 to the frame, and a member is formed that is movable together with the mount I and the head that can freely slide along the transport direction. The light-emitting side sensor is attached to the collet attached to the mount [~spatula 1~], and the light-receiving sensor is attached to the member that can be moved together with the mount head! The pickup error detection method using the mount head according to the present invention is characterized by the fact that the light receiving sensor moves following the movement of the collen 1~ that attracts the semiconductor peremeter 1.

(Function) In this way, in the present invention, a transmission type sensor is used as in the past, but the light-emitting side sensor is installed inside the collet, and the mechanism for conveying the lead frame has a mount head that is slidable along the conveyance direction. A movable slider is also provided, and a light-receiving sensor is installed here. This slider is attached to Maun I/Hen 1~ and is fixed to a lever placed across the transport mechanism, so that both can be moved together, so the light-receiving sensor can follow the movement of Collen 1~. It is.

For this reason, even if a plurality of semiconductor pellets are arranged on the bed of the lead frame and the mounting position and the semiconductor pellet pickup position are not arranged in a straight line, the light-emitting side sensor installed on the mount head,
Since the operation that always crosses the corresponding light-receiving side sensor 111 is possible, the effect on mass production of improving the index of the device itself and increasing the yield of the die bonding process compared to the conventional method is extremely large.

(Embodiment) An embodiment of the present invention will be described with reference to FIG. 1 and FIGS. 2a and 2b. That is, D/G (Djgit
al) Mount Hen 1 to Part 1 on an X-axis stage installed on an x-y table. First, the head section 1 shown in FIG. 1 is provided with a section 3 for cholera 1 in which a hollow section (not shown) connected to a decompression device is installed in order to fix the semiconductor pellet 2 by suction.

A light-emitting side sensor 4, which is a part of a transmission type sensor, is attached to the collet section 3, and a lever 5 is installed at the head section, so that the collet section 3 exhibits the same behavior as the head, that is, the collen 1 section 3.

On the other hand, the number of semiconductor pellets that are die-bonded to the bed formed on the lead frame may be more than one depending on the model.

The lead frame on which this multi-pin structure semiconductor pellet is mounted has a structure for a DIP type or a mixed type with an SIP type. A bed portion is provided to mount the semiconductor pellets 1 to 1 which are free. The bellow I section connects a part of the lead and fixes it to the metal frame, and the unit bodies obtained by the bed section are continuously formed to form a lead frame, and the length is determined by the number of units. It is classified as short lead frame.

(( In this way, the conveyance path 6 (rail) for conveying the rectangular lead frames is installed in the die bonding device, and the head of each lead frame is The mounting position 7 of the semiconductor pellets mounted 1 to 1 on the conveyor path 6 is controlled.
As is clear from the figure, a slider 8 connected to the lever 5 is installed. This slider 8 consists of a pair of upper and lower members 9.
．． 10, and four balls are installed in the middle thereof, and the lower member 10 slides through the sliding groove]1 formed in the upper member 9. As shown in the figure, the second part 9 and the lower part 10
The shape of is a rectangular parallelepiped. Furthermore, a bearing mechanism 12 is attached to the exposed side surface of the rectangular parallelepiped-shaped lower part 10, and the lever 5 is held between them, so that the lower member 10 of the slider 8 moves as the part 3 of the cholera 1 moves. also move.

Furthermore, a light-receiving side sensor 13 is installed on the lower member 10, and a light-emitting side sensor 4 is installed on the cholera 1 part 3 to form a transmission type sensor.

The operation of the collet part 3 and the light emitting side sensor is as follows.
This will be explained with reference to figures a and b. In this figure, it is assumed that two semiconductor pellets are mounted on the bed portion of the lead frame. As explained in the prior art section, the semiconductor pellet 2 affixed to the organic film affixed to the metal ring is placed at the pick-up position 14 set by the die bonding device, and transported to the mount position 7 by the collet section 3.

At this time, the collet part 3 is a member movable together with the mount head, that is, the lever 5. Pick up position 14, light receiving side sensor 13 and mount position 7 by slider 8
Since it is possible to move on a straight line connecting the semiconductor pellets 2, it is possible to reliably determine whether the semiconductor pellet 2 has been picked up using a transmission type sensor.

FIGS. 2a and 2b show the state in which the position of the semiconductor pellet 2 to be placed at the mounting position 7 has been changed.

In this way, the present invention provides a method for changing the type of semiconductor pellet 2,
When fine-adjusting the position to mount 1 and when the mount position is
When it shifts in the direction (left and right direction of the drawing paper surface), D/G
By changing the X-axis movement reference for operating the head, the light-receiving sensor also moves in the X direction.

Therefore, it is possible to eliminate the wasted operation time of moving the light diagonally after passing through the light receiving sensor which is in a fixed state as in the prior art.

Therefore, it is possible to prevent a drop in the index of the head cycle in which one semiconductor pellet is transported from the pick-up position to the mount position and back again to the pick-up position, and conversely improve the index of this die bonding equipment, which in turn improves the yield of semiconductor pellets. The effects on mass production are significant.

〔Effect of the invention〕

In this way, the method of the present invention eliminates the need for software design that changes the movement of the head from the light-receiving sensor to the mounting position, reduces design costs, and allows production without being limited by the type of semiconductor pellet. This has a great effect on mass production.

=11-

[Brief explanation of drawings]

FIG. 1 is a top view showing the main parts of the device used in the method of the present invention, FIGS. 2a and b are diagrams showing the operation of this device, and FIGS. Top view, Figure 4a, b
is a diagram showing its operation. 1: Head, 2: Semiconductor pellet, 3: Collet part, 4: Light-emitting side sensor 5 lever, 6: Conveyance path, 7: Mount position, 8 Nislider, 9: Upper member, 10: Lower member, 11: Sliding Groove, 12: Light receiving side sensor 1
3: Pick-up position. 2

Claims (1)

[Claims] A mechanism is provided to transport the lead frame that mounts the semiconductor pellet, and a movable member is formed along with the mount head that can slide freely along the transport direction.The light-emitting sensor is attached to the collet attached to the mount head, and the sensor can be moved together with the mount head. A pick-up error detection method using a mount head, characterized in that a light-receiving sensor is arranged on a member, and the light-receiving sensor moves following the movement of a collet that sucks a semiconductor pellet.