JPH0543181B2 - - Google Patents

Abstract

PURPOSE:To improve the operational efficiency of die bonding process by a method wherein two each of die bonding heads are arranged at a specified interval along the carrier path of lead frames to properly adjust the feed of lead frames on the carrier path. CONSTITUTION:Die bonding heads DB1, DB2 are arranged at the specified interval along the carrier path 11 of lead frames 10. A projecting plate 31 projecting the frame 10 on the carrier path 11 is fixed on the upper path of a slider block 32. The frame 10 projected on the specified position of carrier path 11 is intermittently shifted by cam followers 20b, 20a and slide cams 25, 21 respectively at the piece arrayal pitch or double distance to be aligned by projecting an alignment pin on a notch 5 of frame 10. Besides, the feed of frame 10 between heads DB1, DB2 is adjusted by a transfer pawl holder 13. Through these procedures, the operational efficiency of die bonding can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a die bonding device for bonding semiconductor pellets to a lead frame, and in particular,
This invention relates to a die bonding device that is equipped with two die bonding heads and performs die bonding in three ways: two different pellets, two homogeneous pellets, and one pellet within one piece of a lead frame.

(Prior Art) In general, in semiconductor devices, even if the package shape is the same, the semiconductor pellets sealed in the package vary. For example, one package contains two different types of pellets, such as a PNP transistor and an NPN transistor. In addition, there are also packages in which two pellets of the same type (for example, two PNP transistors) are housed in the same package, or one in which one pellet (for example, one PNP transistor) is housed in the same package. Die bonding, which is one step in assembling such a semiconductor device, will be explained below.

As mentioned above, in semiconductor devices that use the same package, lead frames are used in which each piece has the same arrangement pitch in order to share the use of assembly equipment such as a molding die.

FIG. 10 is a partial view showing an example of a lead frame used in a semiconductor device in which two pellets are housed in one package. In FIG. 1A, a portion surrounded by a chain line constitutes one unit (one piece) of the lead frame. One lead frame consists of 36 pieces, and the arrangement pitch of each piece is 3.9mm. Two pellets of the same type or different types are die bonded within one piece of this lead frame. Figure b
As shown in the figure, five leads 1a to 1e are formed in one piece of this lead frame. The tips of the leads 1a and 1b bulge out to form die bonding regions 2a and 2b. The centers of die bonding areas 2a and 2b are each 0.775 mm from the center line in the lead direction of the piece.
It's off. This die bonding area 2a, 2
Pellets 3a and 3b are die-bonded to b, respectively. The pellets 3a, 3b and the tips of the leads 1c to 1e are connected by gold wires shown by broken lines in the figure.

On the other hand, as shown in FIG. 10a, guide holes 4 are formed at equal intervals along one longitudinal side edge of the lead frame. This guide hole 4 is
It is located on the center line of each piece of the lead frame, and the arrangement pitch is the same as that of each piece. Also,
Two V-shaped notches 5 are formed in each piece on the side edge opposite to the side edge of the lead frame where the guide hole 4 is formed. Each cutout 5
The center line of is 0.775 with respect to the center line of said piece.
It is off by mm.

FIG. 11 is a partial view showing an example of a lead frame used when storing one pellet in one package. The arrangement pitch of the pieces constituting this lead frame is the same as that of the lead frame shown in FIG. Further, the sizes and positions of the guide holes 4 and notches 5 formed in this lead frame are also the same as those of the lead frame shown in FIG. 10. Three leads 1f to 1h are formed on each piece of this lead frame. lead 1f
The tip part swells out and forms the die bonding area 2c.
is formed. This die bonding area 2c
The center of is on the center line of the piece in the lead direction. Pellet 3 is placed in this die bonding area 2c.
c is die-bonded. Also, pellet 3
and the leads 1g and 1h are connected by gold wires indicated by broken lines in the figure.

FIG. 12 is a block diagram schematically showing the configuration of a conventional die bonding apparatus.

The lead frame before die bonding is fed out one by one by the loading mechanism section 110,
It is placed on the conveyance path 150. The sent-out lead frame moves on the conveyance path 150 and is sent to the preform pasting mechanism section 120. The preform attaching mechanism section 120 attaches a preform material, such as a piece of gold silicon tape, to the die bonding area within each piece of the lead frame.

The lead frame with the preform material pasted thereon is transferred to the next die bonding head 130. The die bonding head 130 selects a good product from among the pellets placed at a predetermined position and chucks it in a collection. Then, the chucked pellet is pressed onto the preform material in the heated die bonding area of the lead frame to fix it.

The die-bonded lead frame is transferred to the unloading mechanism section 140 and stored in a predetermined lead frame storage container.

A case where two pellets of the same type are die bonded to the lead frame shown in FIG. 10 using such a die bonding apparatus will be described.

The lead frame taken out from the loading mechanism section 110 is intermittently transferred on the conveyance path 150 in the direction shown by the arrow in FIG. 10 at a piece arrangement pitch of 3.9 mm. Such transfer of the lead frame is carried out by hooking a claw reciprocally driven by a cam device or the like into the guide hole 4 of the lead frame.

On the other hand, in connection with the die bonding head 130, a positioning pin is provided which is pressed against the notch 5 of the lead frame. The lead frame transferred to a predetermined position on the die bonding head 13 is accurately positioned by these pins. When the positioning is completed, the pellet is die bonded to the die bonding area 2b.

When the first die bonding is completed, the pin is removed from the lead frame and the cam device is started. And this lead frame
After advancing 1.55 mm, the cam device comes to an intermediate stop. Then, since the center distance between the die bonding areas 2a and 2b of this lead frame is 1.55 mm, the next die bonding area 2a will stop at a predetermined die bonding position. At this position, second die bonding is performed in the same manner as described above.

When the second die bonding is completed, the cam device is subsequently driven, and as a result, the pitch is increased by one pitch (3.9 mm) from the first die bonding.
The lead frame stops when it advances. As a result, the die bonding area 2b of the next piece
Die bonding is performed.

Thereafter, the cam device performs an intermediate stop in the same manner as described above, so that pellets of the same type are die bonded to the die bonding regions 2a and 2b of each piece.

On the other hand, when die bonding two different kinds of pellets to the lead frame shown in FIG. 10, a die bonding apparatus equipped with two die bonding heads 130a and 130b is used as shown in FIG. It is also possible to use The lead frame taken out from the loading mechanism section 110 is intermittently transported along the transport path 150 at a pitch of 3.9 mm. And the preform pasting mechanism section 120a
Then, a preform material is attached to the die bonding area 2b, and one of the pellets is further die bonded to the die bonding area to which the preform material is attached in the die bonding head 120a. Then, in the next preform pasting mechanism section 120b, the preform material is pasted onto the die bonding area 2b, and furthermore, the preform material is pasted onto the die bonding head 1.
At 30b, the other pellet is die bonded to the area 2b.

(Problems to be Solved by the Invention) However, since the die bonding apparatus shown in FIG. 12 is equipped with only one die bonding head, it is difficult to die bond two different types of pellets in one piece. The problem is that it cannot be done. Therefore, when die bonding two different types of pellets in one piece, two different devices as described above are used to place the different pellets in the die bonding area 2a,
It is necessary to perform die bonding on each of 2b. Alternatively, if one device is used, the pellet in the die bonding head must be replaced and the lead frame must be run through the conveyance path twice for die bonding. Whichever method is taken, the shingles are time-consuming and significantly reduce the production efficiency of semiconductor devices.

Further, the center position of the die bonding area 2c of the lead frame shown in FIG. 11 is the center position of the die bonding area 2c of the lead frame shown in FIG.
The center positions of a and 2b are different from each other. Therefore, in order to perform die bonding on this lead frame using the above-mentioned die bonding device, the position of the die bonding head must be moved or the position of the feed claw of the lead frame driven by the cam device must be changed. There is a need. However, these operations are very cumbersome and therefore significantly reduce the production efficiency of semiconductor devices. Furthermore, if the positions of the die bonding head and feed claw are not changed correctly, the accuracy of die bonding will be reduced, resulting in a reduction in product yield and reliability of the semiconductor device.

By the way, when two pellets of the same type are die-bonded using the die bonding apparatus shown in FIG. 13, the following inconvenience occurs. That is, due to the design of electronic circuits, two pellets of the same type housed in one package are required to have characteristic values as close as possible. To this end, it is desirable that the two pellets housed in one package be from the same wafer.

However, according to the die bonding apparatus shown in FIG.
Pellets taken out from individual wafers are die-bonded into one piece by means of a and 12b. Therefore, the two pellets in one piece are from different wafers, resulting in the problem that the above requirements cannot be met.

The present invention has been made to solve these problems, and it is possible to bond two parts into one piece of a lead frame using one die bonding device.
An object of the present invention is to provide a die bonding apparatus that can efficiently die bond three pellets of the same type, two pellets of different types, and one pellet.

Another object of the present invention is to provide a die bonding apparatus that can make the characteristic values of both pellets the same when die bonding two pellets of the same type into one piece of a lead frame.

(Means for Solving the Problems) In order to achieve the above object, the present invention has the following features.

That is, the die bonding apparatus according to the present invention has the following features:
Two die bonding heads are provided along the lead frame conveyance path and spaced apart from each other by a predetermined distance.

The lead frame is sent to this conveyance path.
This is done by the loading mechanism. This loading mechanism section is equipped with a mechanism that appropriately changes the initial position of the lead frame sent out onto the conveyance path.

The lead frame sent out to the conveyance path is intermittently fed by the lead frame transfer means at a distance equal to or twice the piece arrangement pitch of the lead frame. Further, this lead frame transfer means includes an intermediate stop mechanism that stops the movement of the lead frame during the intermittent feeding of the lead frame. Further, the lead frame transfer means includes: between the two die bonding heads;
It is also equipped with a variable feed rate mechanism that changes the feed rate of the lead frame.

(Example) The configuration of a die bonding apparatus according to this example is shown in a block diagram as shown in FIG. 13. That is, the die bonding apparatus according to this embodiment includes a loading mechanism section, a first preform pasting mechanism section, a first die bonding head DB1, and a second die bonding head DB1.
It consists of a preform pasting mechanism section, a second die bonding head DB2, and an unloading mechanism section.

However, the features of this embodiment reside in the lead frame transfer means shown in FIGS. 1 to 3 and the loading mechanism section shown in FIG. 4. By appropriately controlling the amount of feed of the lead frame on the conveyance path using this transfer means, etc., the same die bonding device can produce three pellets: two different pellets, two pellets of the same kind, and a single pellet. The die bonding on the street is done skillfully. Note that the lead frame used in this example is the same as that shown in FIGS. 10 and 11.

The transfer means of the die bonding apparatus according to this embodiment will be explained below with reference to FIGS. 1 to 3.

FIG. 1 is a front view of the transfer means, particularly when die bonding two different types of pellets.

In the figure, reference numeral 11 denotes a conveyance path through which the lead frame is intermittently conveyed. The lead frame is transported along this transport path 11 in the longitudinal direction. 12a-12
f is a claw holder, and 13 is a transfer claw holder. At the upper ends of the pawl holders 12a to 12f and the transfer pawl holder 13, triangular pawls 14 are provided which serve as a so-called ratchet mechanism. The tip of this claw 14 is inserted from below into the guide hole 4 of the lead frame shown in FIG. As described later, each claw holder is reciprocated along the direction of the conveyance path 11, so that the lead frame is intermittently moved rightward on the conveyance path 11. Note that the transfer claw holder 13 can move the claws of the transfer claw holder 13 up and down independently of other claw holders. This vertical movement of the claw is performed by a cylinder (not shown) provided in the transfer claw holder 13.

The claw holders 12a to 12c and the transfer claw holder 13 are fixed to the shaft 15a, and the claw holders 12d to 12f are fixed to the shaft 15b. A connecting member 16 is attached to the shaft 15a.
One ends of a and 16b are inserted and fixed. Further, the shaft 15b includes connecting members 16c and 1.
One end side of 6d is inserted and fixed. Connecting member 1
A shaft 17a is inserted and fixed at the other ends of the connecting members 16c, 16d, and a shaft 17b is inserted and fixed at the other ends of the connecting members 16c, 16d.

18 is a cylinder attached and fixed to a structural vertical plate 19. The distal end of the movable rod of this cylinder 18 is attached to a connecting member 16a. 20a and 20b are connecting members 1
6a and 16b are each individually attached cam followers.

21 is a slide cam provided opposite to the connecting member 16a. This slide cam 21 hits the cam follower 20b and the cylinder 18
This restricts the movement of the connecting member 16a that is driven to the right (that is, the movement of the claw 14 in the right direction). The slide cam 21 is a guide member 22
It is supported in a vertically slidable manner by a cylinder, and is driven by a cylinder not shown in the figure. Further, a base portion of a stay 23 that supports a stopper 24 is attached to the guide member 22. The stopper 24 limits the movement of the connecting member 16a driven leftward by the cylinder 18 (that is, the leftward movement of the claw 14).

On the other hand, a slide cam 25 is provided opposite the connecting member 16b. This slide cam 25
bumps against the cam follower 20b and limits the movement of the connecting member 16b (that is, the movement of the claw 4), which moves in the right direction together with the connecting member 16a. The slide cam 25 is supported by a guide member 26 so as to be slidable in the vertical direction, and is driven by a cylinder not shown in the figure.

A coupling member 27 is attached to the right end of the shaft 17a. A slide cam 28 is provided in contact with the coupling member 27 so as to be slidable in the vertical direction. This slide cam 28 is attached to a cam follower 20 attached to the left end of the shaft 17b.
c and is driven by a cylinder not shown in the figure.

In addition, in the same figure, the DB indicated with the arrow
1 and DB2 indicate the respective positions of the first die bonding head and the second die bonding head described above. Further, in the figure, numeral 10 shows a plan view of the lead frame that is transported through the conveyance path 11, and is shown for reference in order to make it easier to understand the positional relationship between each die bonding head and the guide hole 4 of the lead frame. . Loading mechanism and die bonding head not shown in the diagram
As described above, the preform material pasting mechanism sections are installed at appropriate positions between the die bonding head DB1 and the die bonding head DB1, and between the die bonding head DB1 and the die bonding head DB2. Further, an unloading mechanism section not shown in the figure is installed at the right end of the conveyance path 11 in the figure.

Next, the configuration of the loading mechanism section will be explained with reference to FIG. 4. In this figure, the same parts as in FIG. 1 are indicated by the same reference numerals.

31 is an ejecting plate for ejecting the lead frame 10 into the conveyance path 11. This protruding plate 31 is fixed to the upper part of the slide block 32. The slide block 32 is inserted into slide shafts 34a and 34b whose both ends are supported by bearing plates 33a and 33b, so that the slide block 32 can be moved in the horizontal direction. The slide block 32 is driven by a cylinder not shown in the figure.

Further, below the bearing plate 33a,
A stopper shaft 35 is screwed on. A stopper holder 36 is attached to the tip of the stopper shaft 35 on the bearing plate 33b side. Three stoppers 37 are vertically attached to the inner surface of the stopper holder 36, divided by 120 degrees (however, only one stopper is visible in the figure). The height of each stopper 37 is appropriately set according to the amount of protrusion of the lead frame 10. The lower end surface of the slide block 32 abuts against the tip of the stopper 37, thereby limiting the amount of movement of the slide block 32.

As shown in FIG. 1B, a recess 38 is formed at the tip of the stopper shaft 35 in 120 degree divisions. Stopper shaft 35 in which recessed portion 38 is formed
The tip of the bearing plate 33b is fitted into a hole 39 formed in the bearing plate 33b with some play. Then, as shown in FIG. b, the bearing plate 33
A small hole 40 is formed that penetrates the hole 39 from below b. A steel ball 41 is loosely fitted into this small hole 40. This steel ball 41 is attached to a spring 42 whose lower part is supported by a spring plunger 43.
When the steel ball 41 is pushed upward, the recess 38 of the stopper shaft 35 engages with the steel ball 41, and the position of the stopper 37 is locked.

On the other hand, a stopper handle 44 is attached to the other end of the stopper shaft 35, and by rotating the stopper handle 44,
An appropriate stopper 37 is selected.

Next, the operation of the die bonding apparatus having the above-described configuration will be explained.

First, the case where two different kinds of pellets are die bonded to the lead frame shown in FIG. 10 will be described.

As shown in FIG. 5a, the separation distance between die bonding head DB1 and die bonding head DB2,
That is, the distance L between the collectors of each die bonding head is set to be 1.55 mm shorter than an odd multiple of the piece arrangement pitch (3.9 mm) of the lead frame. Therefore, L=3.9×n-1.55 (mm)
It can be expressed as In this embodiment, n=179. The separation distance between die bonding heads DB1 and DB2 is the same for the three types of die bonding described above.

The position of each claw 14 shown in FIG.
When the lead frame taken out from the loading mechanism section is fed in pitches, the center of the die bonding area 2b (hereinafter referred to as area B) of the lead frame is placed in the die bonding head DB1 and the die bonding area 2a (hereinafter referred to as area A). The center of each is set to be on the die bonding head DB2.

Further, the positioning pins 45 provided in association with each die bonding head are located at the same position as each die bonding head, as shown in FIG. 5a. However, this positioning pin 45
As will be described later, the structure is such that its position is changed during die bonding of a single pellet.

When performing die bonding of different types of pellets,
The lead frame has one pitch (3.9mm) of conveyance path 11.
It is transferred intermittently. For this purpose, the slide cam 25 is driven upward as shown in FIG. As a result, the distance between the cam follower 20b attached to the connecting member 16b and the slide cam 25 is set to a distance equal to one pitch (3.9 mm). At this time, the distance between the cam follower 20a attached to the connecting member 16a and the slide cam 21 is one pitch or more. Therefore, the connecting member 20 driven rightward by the cylinder 18
b etc., their movements are restricted by the slide cam 25, so each of the claws of the claw holders 12a to 12c and the transfer claw holder 13 reciprocates by one pitch. At this time, since the movement of the shaft 17a is transmitted to the shaft 17b via the coupling member 27 and the slide cam 28, each of the claws of the claw holders 12d to 12f also performs one-pitch reciprocating movement together with the respective claws. .

On the other hand, with respect to the loading mechanism shown in FIG. 4, when performing die bonding of different kinds of pellets, the operator rotates the stopper handle 44 to select the stopper 37 for die bonding of different kinds of pellets. The length of this stopper 37 is set so that when the lead frame placed on the ejecting plate 31 is ejected by a cylinder (not shown), the guide hole 4 of the lead frame is at the position of the claw 14 of the claw holder 12a. has been done.

Therefore, when the lead frame is projected from the loading mechanism into the conveyance path 11, the lead frame is hooked by the claws of the claw holder 12a and is moved pitch by pitch in the right direction in FIG. transferred in order. Thereafter, this lead frame is hooked with another hook and transported further to the right along the transport path 11.

When the first piece of the lead frame reaches the position of the die bonding head DB1, the positioning pin 45 protrudes forward and its tip is inserted into the notch 5 of the lead frame, thereby positioning the lead frame. It can be done.

Then, die bonding is performed by a collector (not shown) of the die bonding head DB1 chucking, for example, a PNP transistor and pressing it against the heated region B of the lead frame. When die bonding in area B is completed, the positioning pins 45 are moved back and the lead frame is transferred one pitch. Then, die bonding is performed on region B of the next piece in the same manner as described above.

The lead frame on which die bonding in area B has been completed is further transported to the right along the conveyance path and reaches the die bonding head DB2. Then, after the lead frame is positioned by the positioning pins 45 as in the case of the die bonding head DB1, die bonding of, for example, an NPN transistor is performed in the area A.

The lead frame on which die bonding of the two different types of pellets has been completed is transferred to an unloading mechanism installed at the right end of the conveyance path 11, where it is stored in a predetermined container.

Note that the preform pasting mechanism section placed in front of each die bonding head is also installed in the same positional relationship as each die bonding head. Therefore, the die bonding head
The preform pasting mechanism section installed in front of DB1 sticks preform materials to area B of the lead frame, and the preform pasting mechanism section installed before die bonding head DB2 sticks preform materials to area A of the lead frame. .

Next, the case of die bonding a single pellet will be explained.

In this case, the lead frame shown in FIG. 11 is used.

In this case, die bonding head DB1 is
Die bonding is performed on odd numbered pieces of the lead frame, and die bonding head DB2 is used for die bonding on even numbered pieces. For this purpose, it is necessary to feed the lead frame two pitches. To feed the lead frame 2 pitches,
As shown in FIG. 2, the slide cam 21 is pushed down by a cylinder (not shown). As a result, the distance between the cam follower 20a attached to the connecting member 16a and the slide cam 21 is
The distance is 2 pitches of the lead frame (7.8mm). Furthermore, the slide cam 25 is also pushed down. As a result, the distance between the cam follower 20b and the slide cam 25 becomes longer than the distance of two lead frame pitches. Therefore, since the movement of the cylinder 18 is limited by the slide cam 21, the claw 4 will reciprocate by two pitches of the lead frame.

On the other hand, as can be seen by comparing FIG. 5a and FIG. must be close to. For this purpose, as shown in FIG.
Shift by 0.775mm. As a result, the shaft 15a
moves to the right, so each claw moves to the right by 0.775mm.

When the claw 14 is moved to the right as described above, the initial position of the lead frame projected into the conveyance path 11 must also be changed accordingly. This is done by rotating the stopper handle 44 on the loading mechanism to select the single pellet stopper 37. That is, since the stopper 37 for single pellets is set to be 0.775 mm shorter than the stopper 37 for different kinds of pellets, this can be realized by increasing the amount of protrusion of the ejecting plate 31 by that much.

On the other hand, regarding the die bonding head DB2, as can be seen by comparing FIGS. 5a and 5b, in the case of a single pellet, it is necessary to shift the die bonding head DB2 by 0.775 mm to the left compared to the case of a different type of pellet.
Moreover, as mentioned above, the die bonding head
In relation to DB1, move the lead frame to the right by 0.775
Since the lead frame is shifted by mm, the lead frame must be fed only once between die bonding heads DB1 and DB2, which is 1.55 mm shorter than 2 pitches. The transition distance of the lead frame between the die bonding heads DB1 and DB2 is adjusted by the transfer claw holder 13, as will be described later.

As the feed amount of the lead frame is shortened by 1.55 mm by the transfer claw holder 13, it is necessary to move the position of each claw of the claw holders 12d, 12e, and 12f related to the die bonding head DB2 by 1.55 mm to the left. . This can be achieved by pulling the slide cam 28 upward as shown in FIG. 2b. That is, since the step of the slide cam 28 is set to 1.55 mm, when the slide cam 28 is pulled upward, the claws of each of the claw holders are shifted to the left by 1.55 mm.

When the position of each claw and the amount of protrusion of the lead frame are set as described above, the lead frame protruded from the loading mechanism into the conveyance path 11 is moved two pitches at a time by each claw of the claw holders 12a to 12c. Transferred intermittently. Then, a PNP transistor, for example, is die-bonded to the odd-numbered piece by the die bonding head DB1. The lead frame that has undergone die bonding by the die bonding head DB1 is further transferred to the right by the claws 14 of the transfer claw holder 13. Then, when the lead frame is fed by the last pitch, the transfer claw holder 13 is 1.55 pitch higher than the 2 pitch pitch.
At a point shorter than mm, a cylinder (not shown) is driven to lower the claw 14. As a result, the lead frame is inserted only once between die bonding head DB1 and die bonding head DB2.
It will be transported 1.55mm shorter distance than Pituchi.

After the transfer distance is adjusted between the two die bonding heads in this way, the lead frame is further transferred to the right side by the claws 14 of the claw holders 12d, 12e, and 12f, and then transferred to the die by the die bonding head DB2. Bonding is performed.

Next, the case where two pellets of the same type are die bonded using the lead frame shown in FIG. 11 will be described.

In this case, die bonding head DB1 is
The die bonding head DB2 is in charge of die bonding the two pellets of the odd numbered pieces of the lead frame, and the die bonding head DB2 is in charge of die bonding of the even numbered pieces. Therefore, the lead frame is fed two pitches, but since two pellets are die bonded in one piece using the same die bonding head, the lead frame is stopped midway at a point 1.55 mm shorter than the two pitches. Die bonding is performed on area B of the lead frame, and then, after advancing 1.55 mm, die bonding is performed on area A. Fig. 5 c-1 shows the intermediate stop state, and Fig. 5 c-2 shows the state when pitch feeding is completed.

As can be seen by comparing Figure 5a and Figure 5c-2, in the case of die bonding of homogeneous pellets,
It is necessary to shift the lead frame by 1.55 mm to the right compared to when using different pellets. Therefore, as shown in FIG. 3, the slider 29 is shifted by 1.55 mm to the right compared to the case in FIG. 1, thereby changing the position of each claw 14.

In addition to changing the position of the claw 14 described above,
The initial position of the lead frame projected into the conveyance path 11 must also be shifted to the right by 1.55 mm.
This is accomplished by rotating the stopper handle 44 of the loading mechanism to select the stopper 37 for like pellets, as described above. That is, since the stopper 37 for the same kind of pellets is set to be 1.55 mm shorter than that for different kinds of pellets, the amount by which the ejector plate 31 protrudes is increased accordingly.

On the other hand, the slide cam 21 is driven by a cylinder (not shown) and pulled upward. As a result, the distance between the cam follower 20a of the connecting member 16a and the slide cam 21 is smaller than 2 pitches.
The distance is set to be 1.55mm shorter. This state is the above-mentioned intermediate stop state. When the slide cam 21 is pulled down, the distance between the cam follower 20a and the slide cam 21 becomes two pitches. Furthermore, since the slide cam 25 is pulled down and the distance between the cam follower 20b and the slide cam 25 is longer than two pitches, the movement of the cylinder 18 is restricted by the slide cam 21. Further, as shown in the figure, the slide cam 28 has been pulled upward.

When the feed amount of the loading mechanism section and the position of each claw 14 are set in this way, the lead frames protruding from the loading mechanism section are sequentially transferred rightward along the conveyance path 11. At this time, since the slide cam 21 is pulled upward during the first two-pitch feed, the lead frame stops at a position 1.55 mm shorter than the two-pitch feed. In this state, as shown in FIG. 5c-1, die bonding of area B is performed by die bonding head DB1. When this die bonding is completed, the slide cam 21 is lowered to further move the lead frame by 1.55 mm to the right, completing the 2-pitch feeding. In this state, die bonding of area A is performed as shown in FIG. 5c-2.

In this way, when the die bonding of two pellets of the same type is completed one piece at a time, the lead frame is further transferred to the right along the conveyance path 11. And die bonding head DB
1 and the die bonding head DB2, the transfer takes place 1.55 mm shorter than the two pitches, as in the case of the single pellet described above. Thereafter, the lead frame is further moved to the right by the claws of the claw holders 12d to 12f, and two pellets of the same type are die-bonded to even-numbered pieces by the die bonding head DB2. Of course, in this case as well, an intermediate stop is performed as described above.

Note that the above-described movement of the lead frame is not limited to restricting the movement of the cylinder 18 using the slide cams 21 and 25 as explained in the previous embodiment. For example, this can be achieved by driving the connecting member 16a or the like with a cam. FIG. 6 shows an embodiment of a transfer means that changes the pitch feed of the pawl 14 by such a cam drive. Figure a shows a plan view, and figure b shows a front view. In addition, in the same figure, the same parts as in FIGS. 1 to 3 are indicated by the same reference numerals.

Slight rails 51a and 51b are provided opposite both ends of the base plate 50. A slide unit 52 is attached to these slide rails 51a and 51b.
a and 52b are slidably attached. A slide base plate 53 is fixed to the slide units 52a and 52b. Three feed cams 55a, 5 are attached to a shaft 54a whose both ends are rotatably supported by a slide base plate 53.
6a and 57a are inserted and fixed. These cams are for driving the claws 14 of the claw holders 12a, 12b, 12c and the transfer claw holder 13. Below, cams 55a, 56
a, 57a is called an L side feed cam.

On the other hand, there is a shaft 54b opposite to the shaft 54a, and three feed cams 55b, 56b, and 57b are also inserted and fixed to this shaft 54b. These cams are connected to the claw holders 12d, 12
This is for driving each claw 14 of e and 12f. Hereinafter, these cams will be referred to as R-side feed cams.

A pulley 58 is provided on the shafts 54a and 54b.
a and 58b are attached respectively. Also. A motor 60 is provided between the shafts 54a and 54b, and pulleys 58c and 58d attached to the rotating shaft of the motor 60 and the pulley 5
8a, 58b, belts 59a, 59b
is being passed over.

On the other hand, a lever bracket 61 is attached to the base plate 50.
a and 61b are provided facing each other. Levers 62a, 62b whose bases are swingably supported are attached to the lever brackets 61a, 61b. Cam followers 63a and 63b are individually attached to the tip portions of the levers 62a and 62b, respectively. The cam follower 63a is connected to the shaft 15 that supports the pawl holder 12a, etc.
It is in contact with a connecting member 64a attached to a. Moreover, the cam follower 63b of the lever 62b is
Connecting member 64 supporting the claw holder 12 etc.
It is in contact with b.

Further, a cam follower 65a attached to the middle of the lever 62a is in contact with one of the L side feeding cams. Further, a cam follower 65b attached to the middle of the lever 62b is in contact with one of the feeding cams on the R side.

A long hole 66 is formed in the slide base plate 53. A switching follower 67 is loosely fitted into this elongated hole 66. This switching follower 67 is
It is adapted to move in the Y direction shown in the figure in conjunction with a switching lever 68 that swings horizontally about a fulcrum A. The tip of the switching lever 68 is inserted into a holding member 69 fixed to the base plate 50, and is biased downward. Furthermore, grooves 70 are formed at both ends and the center of the inner hole of the holding member 69. This concave groove 70 and the lever 68 are engaged to lock the position of the lever 68.

In the embodiment described above, when the operator lifts the lever 68 and moves it horizontally to the left and right,
Accordingly, a force in the Y direction is applied to the slide base plate 53 via the switching follower 67. As a result, the slide units 52a, 52b move along the slide rails 51a, 51b. This allows the L side and R side to contact the cam followers 65a, 65b attached to the levers 62a, 62b.
Each feed cam on the side can be switched.

When the motor 60 is rotationally driven, the feed cam rotates, and the levers 62a and 62b are driven following the cam curve, so that each claw 14 reciprocates at a predetermined pitch corresponding to the cam curve. You will be exercised.

Figures 7 to 9 show the cam diagrams of the L side and R side feed cams, the solid line shows the cam diagram of the L side feed cam, and the chain line shows the cam diagram of the R side. ing.

FIG. 7 shows a cam diagram of feed cams 55a and 55b for dissimilar pellet die bonding. For die bonding of different pellets,
As mentioned above, die bonding head DB1,
Since there is no need to adjust the feed amount of the lead frame with DB2, the cam diagrams on the L side and R side are the same. The DB indicated by the arrow in the same figure is
It shows the timing to perform die bonding.

The reason why the cam displacement in the feed section shown in the figure is longer than one pitch (3.9 mm) of the lead frame is due to the inclination of the claw 14, the clearance between the claw 14 and the guide hole 4 of the lead frame, etc. Because I did. Also, the cam step in the return section is
The reason why it is longer than the length of one pitch of the lead frame (3.9 mm) is because when the claw 14, which is the ratchet mechanism, returns to the left, it hits the back side of the lead frame and tilts to the right. This is because the tip of the claw 14 will not enter the guide hole 4 of the lead frame if it is returned only by one pitch to the left. The same can be said of the cam diagrams shown in FIGS. 8 and 9.

FIG. 8 shows a cam diagram of feed cams 56a and 56b for single pellet die bonding. In this case, as explained in Fig. 2, the amount of lead frame protrusion is 0.775 mm more than when the pellet is of a different type, so the length of the cam when the L side feed cam is at 0 degrees is increased by that amount. The displacement is longer than when using different types of pellets. In addition, in the case of single die bonding, due to the transfer feed between die bonding head DB1 and die bonding head DB2, the cam displacement at 0 degrees of both cams is
There is a difference of 1.55mm.

FIG. 9 shows a cam diagram of a feed cam for homogeneous pellet die bonding. In this case, as explained in FIG.
Since it is protruded by 1.55mm more, the length is increased by that much.
The cam displacement at 0 degrees of the side feed cam is set longer than that for different types of pellets. Also, in this case, due to the transfer feed, the 0 of both cams is
There is a difference of 1.55 mm in cam displacement in degrees.

Although the die bonding apparatus described in the above embodiment is provided with a preform pasting mechanism, the preform pasting mechanism does not need to be provided if the die bonding area of the lead frame is plated with gold in advance. .

Furthermore, the die bonding that is the object of the present invention can be performed without the unloading mechanism installed in the apparatus of the embodiment for storing the lead frame in a container. It is not a required component.

Further, in the embodiment, two examples are shown as the means for transporting the lead frame, but it goes without saying that the present invention is not limited to these, and similar modifications can be made.

In addition, in the description of the embodiment, the first lead frame is used as a lead frame for single pellet die bonding.
The one shown in Figure 1 was used. However, the lead frame shown in FIG. 14, for example, can also be used. In this lead frame, the center of the die bonding region 2c and the center of the notch 5 are on the same line. Therefore, when this lead frame is used, there is no need to move the positioning pins 45 as described above, and work efficiency is further improved.

(Effects) Since the present invention has the above-described configuration, die bonding of two different types of pellets, two of the same type of pellets, and a single pellet can be performed using one die bonding apparatus. ,
Further, when performing the three types of die bonding, there is no need to change the position of the die bonding head, etc., so die bonding models can be easily changed. Therefore, according to the present invention, die bonding efficiency can be significantly improved compared to conventional devices.

Further, according to the die bonding apparatus according to the present invention, it is possible to feed the lead frame two pitches and to make an intermediate stop in the middle, so that the same die bonding head can feed the lead frame in one piece. Two homogeneous pellets can be die bonded. That is, 1
Two pellets of the same type die-bonded into a piece can be taken out from within the same wafer. Therefore, according to the present invention, it is possible to die bond two pellets of the same type having similar characteristic values.

[Brief explanation of the drawing]

FIGS. 1 to 3 are configuration diagrams schematically showing a transfer means which is a main part of a die bonding apparatus according to an embodiment,
FIG. 4 is a configuration diagram schematically showing the loading mechanism section of the die bonding apparatus according to the embodiment, FIG. 5 is an explanatory diagram of pitch feeding of the lead frame of the embodiment, and FIG.
The figure is a block diagram schematically showing a transfer means which is a main part of a die bonding apparatus according to another embodiment, and FIGS. 7 to 9 are cam diagrams of a feed cam used in the embodiment shown in FIG. 6. , FIGS. 10 and 11 are explanatory diagrams of a lead frame to be die bonded, and FIGS. 12 and 13 are block diagrams of a conventional die bonding apparatus. However, the configuration of the die bonding apparatus according to the embodiment of the present invention also differs from the thirteenth example.
As shown in the figure. FIG. 14 is an explanatory diagram showing another embodiment of the lead frame used for single pellets. 11... Conveyance path, 12a-12f... Claw holder, 13... Transfer claw holder, 14...
Claws, 15a, 15b...Shaft, 16a-1
6d...Connecting member, 17a, 17b...Shaft, 18...Cylinder, 21, 25, 28...Slide cam, 29...Slider, 31...Ejecting plate, 32...Slide block, 53...
...Slide base plate, 55a, 56a, 57a,
55b, 56b, 57b...Feed cam.

Claims (1)

[Scope of Claims] 1. Two die bonding heads arranged at a predetermined distance apart along a lead frame transport path; a loading mechanism that changes the initial position of the frame; a feeding mechanism that intermittently feeds the lead frame sent to a predetermined position on the conveyance path at a distance equal to or twice the piece arrangement pitch of the lead frame;
A lead frame transfer means is provided, which includes an intermediate stop mechanism that stops the lead frame in the middle of the intermittent feeding, and a variable feed amount mechanism that changes the feed amount of the lead frame between the two die bonding heads. A die bonding device characterized by: