JP3498050B2 - Die bonder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a die bonder for which a drive mechanism in regard to application is lightweight by satisfying required quality, and applying silver paste on a lead frame at a high speed. SOLUTION: A dispenser 22a is attached to a dispenser attaching plate 14b via a spherical joint 31 halfway, and an edge needle 9c is held at a slight interval with a lead frame 3. An upper spherical part 32 is engaged with the XY plane operation part of an XY-drive mechanism 27, and, when the XY-plane operation part is moved, the edge of the needle 9c is rotated on the spherical face as the dispenser 22a is used as a fulcrum. During the operation, the dispenser 22a injects a number of granular silver paste 6, and a prescribed application shape is drawn in a land part 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die bonder for mounting a semiconductor die (hereinafter referred to as a die) on a lead frame, and in particular, bonding the die to the lead frame with a paste-like bonding agent such as silver paste or resin. About the die bonder.

[0002]

2. Description of the Related Art As a bonding agent for mounting a die on a predetermined position (land portion) of a lead frame, solder, silver paste, resin or the like is used. The following method has been generally adopted for joining with the silver paste. FIG. 7 is a perspective view of a conventional die bonder, focusing on a mechanical portion for applying a silver paste to a lead frame. This is a land portion 4 of a strip-shaped lead frame 3 that is transported on the rail 2 of the die bonder 1.
In the figure, the state of applying the silver paste 6 is drawn. Thereafter, a die whose size is slightly smaller than the land portion 4 is mounted on the land portion 4 at another position of the die bonder 1.

Explaining this coating mechanism in detail, the vertical drive unit 7 is fixed to the main body of the apparatus, and the dispenser 8 is fixed to the vertical drive unit 7. Dispenser 8
Has a needle 9 at its tip, from which a predetermined amount of silver paste 6 is discharged. In addition, the vertical drive unit 7
Is mainly composed of a motor 11, a ball screw 12, and an LM guide 13, and the dispenser mounting plate 14 moves up and down as the motor 11 rotates.
At the time of application, the needle 9 at the tip of the dispenser 8 descends and approaches the land portion 4, and a predetermined amount of the silver paste 6 is ejected there. It should be noted that the dispenser 8 generally has a structure for discharging a predetermined amount of the silver paste 6 therein by applying high-pressure air or the like having a predetermined pressure for a predetermined time.

[0004] The quality of the bonding layer of the silver paste 6 after the die is mounted is generally required to be as follows. -There are no large air bubbles.・ Silver paste 6
Is thinly spread over the entire lower surface of the die and slightly protrudes from the periphery of the die without being too much, but the protruding silver paste 6 does not extend beyond the side surface of the die and reach the upper surface. in this way,
Regarding the application of the silver paste 6, the required quality is high. These are required in order to prevent a defect from occurring when the final product such as an IC is mounted on a printed board. One of the purposes is to keep the bonding strength of the die above a certain level. Another purpose is that the die easily generates heat during operation and is easily peeled off from the lead frame 3 having a different coefficient of thermal expansion. It is to prevent.

By the way, the size of the die is □ 0.2 mm
~ □ It varies from about 30 mm. Generally, □ 2m
When mounting a small die having a size of m or less, a predetermined amount of the silver paste 6 may be discharged onto one point in the center of the small land portion 4. FIG. 7 shows a form in which such small land portions 4 are coated. However, the silver paste 6 used here is in a paste form, but is roughly classified into two types of viscosity regions. One is 8,000-15,
It has a relatively low viscosity of 000 cps, the other is 25,
It has a relatively high viscosity of 000 to 30,000 cps, and has the following phenomena and problems when used. First, when the viscosity of the silver paste 6 was low, the silver paste 6 drooped down from the tip of the needle 9 when rising at high speed after the end of discharge. This is because even if the electromagnetic valve for the high pressure air that has been applied is closed to stop the discharge, there is still some residual pressure in the dispenser 8 immediately after that, so when the dispenser 8 moves at high speed, the needle 9 The silver paste 6 was slightly dripping from the tip. Therefore, the coating amount slightly increased, and when the die was mounted, the silver paste 6 overflowed from the die. Alternatively, it fell down to a place other than the land portion 4 and could not satisfy the required quality.

Further, when the viscosity of the silver paste 6 is high, if the silver paste 6 rises at a high speed after the end of the discharge, the silver paste 6 will hang down by pulling a thread from the tip of the needle 9. This is the silver paste 6 at the normal application height.
The silver paste 6 still bridges between the tip of the needle and the land 4 even if the discharge of the ink is stopped, and if the dispenser 8 rises as it is, the silver paste 6 draws a thread from the tip of the needle 9 and hangs down. Met. In this case, when the next land portion 4 was applied in that state, the next application amount slightly increased, and when the die was mounted, the silver paste 6 spilled out of the die.

Therefore, in order to prevent these problems, when the viscosity of the silver paste 6 is low, the dispenser 8 is slowly raised after the end of the discharge to prevent the liquid dripping. Further, when the viscosity of the silver paste 6 is high, the dispenser 8 slightly stops after the end of the discharge, and once stopped, the dispenser 8 is again raised to cut the string-drawn silver paste 6. That is, when the dispenser 8 is lifted up after the application is finished, the above-mentioned workarounds are adopted instead of simply rising up. Therefore, as shown in FIG. 7, the vertical drive unit 7 is a drive mechanism that uses the motor 11 and is capable of precise vertical movement.

On the other hand, when mounting a large die,
Only by ejecting the silver paste 6 to one point in the center of the large land portion 4, the required quality described above cannot be satisfied. This is because if the amount is too small, the silver paste 6 will not spread over the entire surface of the die, and if it is too large, the silver paste 6 will largely protrude from the periphery of the die (especially near the center of the four sides of the die).

Therefore, when the silver paste 6 is applied to the large land portion, the following method is generally adopted.
This will be described with reference to FIGS. 8 and 9. Figure 8
FIG. 6 is a plan view showing a land portion 4 coated with a silver paste 6. Further, FIG. 9 is a perspective view mainly showing the mechanism part for applying. Here, as shown in FIG. 8A, it is applied in an X shape, or with a narrower width of the silver paste 6, a more complicated shape is applied and applied as shown in FIG. 8B. Therefore, as can be seen from the enlarged view of the tip of the dispenser 8a shown in FIG. 9, the tip of the dispenser 8a is provided with a large number of thin needles 9a, and these needles 9a are arranged in the coating shape shown in FIG. (This is the X shape shown in FIG. 8A). This is a so-called multi-nozzle type dispenser. This dispenser 8a
In this case, the silver paste 6 can be applied in a predetermined shape only by descending close to the land 4 and discharging the silver paste 6 and then rising. Therefore, even after mounting a large die, the silver paste 6 is thinly spread over the entire lower surface of the die,
The required quality mentioned above can be satisfied.

[0010]

However, the above-mentioned conventional silver paste coating mechanism section of the die bonder has the following problems. First, it takes a long time to apply the silver paste 6. This is the same reason for the case of the one-point coating shown in FIG. 7 and the case of the complicated coating shape shown in FIG. As described above, in order to prevent the silver paste 6 from dripping from the needle or pulling a thread, the dispenser must be slowly raised or a two-step raising operation must be performed after the application is completed. This is because the.

The next problem is related to the multi-nozzle type dispenser 8a. First of all, if even one of the many needles 9a causes a problem such as clogging,
The silver paste 6 cannot be normally discharged from the needle 9a. If the discharged silver paste 6 is partly missing or has a small amount, air bubbles will be caught therein after the die is mounted. Therefore, it is necessary to constantly maintain the silver paste 6 so that the silver paste 6 can be normally discharged from all the needles 9a. The next problem of the dispenser 8a is how to deal with the product type exchange. When the die to be mounted changes, the silver paste 6 must be applied in a shape suitable for the die, such as its size. Therefore, it is necessary to replace the dispenser 8a with a large number of needles 9a arranged in a suitable shape. This exchanging work is not only time-consuming, but immediately after the exchanging work, air bleeding inside the dispenser 8a and confirmation of the discharge amount must be performed, which is very troublesome. In addition, each die to be produced must have a dispenser 8a having a unique arrangement of needles 9a, which is costly and cumbersome to manage.

Therefore, the following method has come to be often used for coating large lands. It applies while moving a dispenser consisting of a single needle along a desired application shape. This will be described with reference to FIG. The vertical drive unit 7 is fixed to a so-called XY table 16 that can drive the XY plane. Therefore, the dispenser 8 can move in the three XYZ directions. Mainly motor 1 for each axis
1, ball screw 12, and guide rod 17 or LM
Each of the guides 13 is composed of a guide 13 and moves linearly as the motor 11 rotates.

However, this method also has the following problems. Although FIG. 8 is used again, the silver paste 6 is continuously discharged at the time of application in any of the shapes shown in FIGS. 8A and 8B. In addition, the point where the discharge starts and ends is the center of the land portion 4. That is, the needle 9
Starts descending close to the center of the land portion 4, starts discharging the silver paste 6, moves the coating shape by so-called one-stroke writing, and finally returns to the starting point again. Then, the discharge is stopped and the pressure rises. In FIG. 11, the locus of movement of the dispenser is indicated by an arrow (this coating shape corresponds to the X shape shown in FIG. 8A). Specifically, the point A is set as the starting point, and the point A
→ point B → point C → point A → point D → point E again via point E
Return to. When the ejection is started and ended, the silver paste 6 inevitably adheres to the land portion 4 in many cases.
As a result, the silver paste 6 is applied thicker in the center of the land portion 4 (near the point A) than in the surrounding area. If the die is mounted in this way, there is no risk that the silver paste 6 will be spread around the die and air will be trapped therein to trap air bubbles.

However, also here, when the dispenser 8 is lifted after the coating is finished, it is not simply lifted, but after the coating is finished, the dispenser should be slowly raised or a two-step raising operation is required. did not become. The reason for this is as described above.

Now, the discussion will be made again on the coating time.
This method takes a certain amount of time because the needle 9 draws with a single stroke along the application shape, and the needle 9 cannot be raised at a high speed after ejection, so that the application time of the silver paste 6 becomes longer. Was there. In the case of a die bonder that has a relatively high mounting accuracy and mounts a die of about 10 mm, the cycle time is 1 to 1.5 seconds / die, but most of this depends on the application time of the silver paste 6. Naturally, if the die is larger than this, the coating time is extended, and the cycle time is inevitably extended by the extended amount. In the die bonder, the improvement of the processing capacity is always required, and the shortening of the coating time is a major issue, and the one-stroke writing method is the first problem.

The second problem of the one-stroke writing system is the XYZ drive mechanism in which the dispenser is fixed. Especially X
The Y table 16 has a large size and a large size of 300 mm × 300 mm. Although the driving range required for coating is about 30 mm at the most, the large XY table 16 has to be used because of its structure as described above. In addition, the XY table 16 has a motor 1
1 and the LM guide 13 are fixed vertically, and the XY table 16 must support their weight and suppress the occurrence of shaking and inertia of the tip of the needle 9, so that the XY table 16 has high rigidity. Was needed. These are one of the factors that prevent the die bonder from becoming smaller and lighter.

As described above, in order to apply the silver paste 6 in a shape suitable for mounting a large die, there is a method of using a multi-nozzle type dispenser 8a or a method of writing with one needle 9 in a single stroke. However, each had its own difficulties. At the same time, when mounting a small die, the unit price of the product was low, so the die bonder had to be operated at higher speed in order to reduce the manufacturing cost as much as possible. For this reason, even when the silver paste 6 is applied to the small land portion 4 at one point, there have been many demands for higher speed application. Therefore, even if the dispenser 8 including one needle 9 is used, it is necessary to develop a die bonder that requires a short coating time and has a compact coating mechanism.

[0018]

Therefore, the present invention is a die bonder proposed to solve the above-mentioned problems. First, the feature of the die bonder of the present invention is that an XY drive mechanism of a horizontal plane is provided above the dispenser for ejecting the bonding agent in a granular form.
The dispenser is installed above the lead frame with the injection needle at the lower end and supported in the middle , and the upper part of the support part is engaged with the XY drive mechanism.
As the XY drive mechanism is driven, the supporting portion is a fulcrum.
First, the tip of the needle rotates on a spherical surface, and when applying the bonding agent to the lead frame, the dispenser injects a granular bonding agent to a predetermined position of the lead frame. Accordingly, the dispenser can inject the granular bonding agent along the desired shape. Here, during application, the silver paste does not drip from the needle and the needle and the lead frame are not bridged by the silver paste.

Further, in the dispenser, the distance from the supporting portion to the engaging portion with the XY drive mechanism is set shorter than the distance from the supporting portion to the tip of the injection needle.
With this, the dispenser can inject the granular bonding agent along a desired shape with a slight movement of the XY drive mechanism.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a die bonder according to the present invention will be described in detail below with reference to the accompanying drawings.
The same components as those in the conventional example are designated by the same reference numerals as those in the conventional example.

[0021]

Embodiment 1 FIG. 1 shows a die bonder according to Embodiment 1 of the present invention, and is a perspective view centering on a mechanism portion for applying a silver paste 6 to a lead frame 3.
First, the main configuration of the coating mechanism section will be described. The dispenser mounting plate 14a is fixed to the mounting angle 21 fixed to the apparatus main body. The dispenser 22 is fixed to the dispenser mounting plate 14a.
Further, the dispenser 22 is arranged such that the needle 9b and the lead frame 3 are located at a position where the needle 9b abuts substantially the center of the land portion 4 while the lead frame 3 which is pitch-fed is stopped.
It is fixed with a proper gap between them.

Here, the dispenser 22 will be described. This is not for discharging a predetermined amount of silver paste 6 from the tip of the needle 9b, but for discharging granular silver paste 6 from the tip of the needle 9b. , Popularly called a jet dispenser. Although the internal structure is not shown in detail in FIG. 1, the silver paste 6 can be made to fly by giving a predetermined signal to the current-carrying wire 23. The size of the grain is about 0.02 μL / grain,
It can be small. At the same time, injection is possible even if the frequency is high, and high-speed injection of about 1/5 ms is possible. Further, even the silver paste 6 having a relatively low viscosity described above does not drip at all.

At the time of coating, a predetermined signal is applied to the current-carrying wire 23 while the lead frame 3 fed by pitch is stopped.
The granular silver paste 6 is injected onto the land portion 4. If you are mounting a small die, this method will complete the one-point application. The size of the particles to be ejected is set in advance to an appropriate amount depending on the size of the mounted die. When applying, the needle 9b and the lead frame 3
Is not bridged by the silver paste 6. Thus, it is not necessary to move the dispenser 22 up and down at the time of application. Further, unlike the conventional method, the silver paste 6 does not pull the thread from the tip of the needle 9b.
Therefore, the coating operation can be performed at high speed.

[0024]

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. This is a form suitable for applying one point of silver paste to each land portion on the lead frame 3 in which the plurality of land portions 4 are arranged orthogonal to the pitch feed direction. The mounting angle 21 is the slide unit 2
It is fixed to the slider 26 of 4 and dispenser 2
2 is movable in the 1-axis (Y-axis) direction. Here, the slider 26 has a built-in nut portion that is screwed into the ball screw 12a and a bearing that slides on the guide rod.
The ball screw 12a moves straight along with the rotation. The ball screw 12a is connected to the rotating shaft of the motor 11a. The slide unit 24 is arranged so that its straight-moving direction is orthogonal to the pitch feed direction of the lead frame 3 and that the needle 9b is substantially at the center of the land portion while the pitch feed lead frame 3 is stopped. It is installed in. Also here, an appropriate gap is provided between the needle 9b and the lead frame 3.

According to this structure, while the lead frame 3 is stopped, the needles 9b are arranged in a plurality of land portions 4 on the same row.
The slider 26 may be moved so as to sequentially come on top of each of the land portions 4, and the granular silver paste 6 may be sequentially ejected on each of the land portions 4. This completes the one-point coating for all the land portions 4 on the same row. Also in this application, the dispenser 22
Does not move up and down, and the needle 9b and the lead frame 3 are not bridged by the silver paste 6. Therefore, the coating operation can be performed at high speed.

[0026]

Example 3 The following Example 3 considers application when mounting a large die. That is, the silver paste 6 is applied while drawing a complicated shape as shown in FIG. This will be described with reference to FIG. In this case, the mounting angle 21 is the XY table 16
The dispenser 22 is fixed to the slider 26a of a and can move in the XY plane. An appropriate space is provided between the needle 9b and the lead frame 3. When applying, the needle 9b is placed on the land 4
The XY table 16a may be driven so as to draw a predetermined locus above, and during that time, the granular silver paste 6 may be ejected from the needle 9b at appropriate time intervals.

Also in this application, the dispenser 22 does not move up and down, and the needle 9b and the lead frame 3 are
It is not bridged by the silver paste 6. Therefore, even if the coating shape is complicated, the coating operation can be performed at high speed.

As a supplement to this third embodiment, this form is not only effective when mounting a large die. Although the lead frame 3 in which the plurality of small land portions 4 are arranged in one row orthogonal to the pitch feed direction has been described in the second embodiment, the plurality of land portions 4 are arranged in one row in the lead frame 3. Some are distributed. This is one in which a plurality of lands 4 arranged in a plurality of rows are set as a group, and the group is arranged at a constant pitch in the feed direction of the lead frame 3. (Not shown) Even with the lead frame 3 having such a shape, the dispenser 22 moves in the XY plane and ejects the granular silver paste 6 onto each land portion 4 while the lead frame 3 is stopped. be able to. That is, the dispenser 22 installed on the XY table 16a
Thus, it is possible to apply it to all the land portions of the group.

[0029]

[Embodiment 4] The following Embodiment 4 also considers the mounting of a large die, but devises a method for moving the dispenser along the coating shape. The main configuration of the coating mechanism section will be described with reference to FIG. The XY drive mechanism 2 is attached to the mounting angle 21a fixed to the apparatus body.
7 and the dispenser mounting plate 14b are fixed. The XY drive mechanism 27 includes an X-axis drive motor 28 and a Y-axis drive motor 29, and the rotation of these motors causes an XY plane operation unit (not shown) located on the lower surface of the XY drive mechanism 27 to move to an XY plane. It moves smoothly in a plane. A dispenser 22a is attached to the dispenser attachment plate 14b via a spherical joint 31. On the other hand, the upper part of the dispenser 22a is
The tip is spherical and protrudes, and the spherical portion 32 is X-shaped.
The Y drive mechanism 27 is engaged with an XY plane operation unit (not shown).

Next, the mounting method of the dispenser 22a, the movement of the tip of the needle 9c, and the positional relationship with the lead frame 3 will be described in detail with reference to FIG. Figure 5
(A) is a perspective view showing a state of a moving dispenser 22a. Further, FIG. 5B is a front view (partial cross section) at that time. 5B, the granular silver paste 6 ejected from the tip of the needle 9c is also drawn. A round hole is formed in the dispenser mounting plate 14b, and the outer ring 33 of the spherical joint 31 is press-fitted therein, and the dispenser 22a is fixed to the inner ring 34 of the spherical joint 31. Therefore, the dispenser 22a can rotate on the spherical surface having the radii of LU and LD, respectively, with the upper end and the lower end of the dispenser 22a about the center of the spherical joint 31. On the other hand, the tip of the upper portion of the dispenser 22a has a spherical shape, and the spherical portion 32 is engaged with the XY plane operating portion (not shown) of the XY drive mechanism 27 with almost no resistance. Therefore, when the spherical portion 32 above the dispenser 22a is moved by the XY drive mechanism 27, the dispenser 22a moves with almost no resistance with the center of the spherical joint 31 as the fulcrum. At this time, the tip of the needle 9c moves on a spherical surface having the deepest portion when standing vertically. Here, the dispenser 22a is installed at a height with an appropriate interval provided between the tip of the needle 9c and the lead frame 3.

Next, the operation of applying the silver paste 6 will be described. (See also FIG. 4 at the same time) When the lead frame 3 stops at a predetermined position, the XY drive mechanism 27 operates to move the tip of the needle 9c so as to draw a predetermined coating shape on the land portion 4. Then, during the movement, granular silver paste is ejected from the tip of the needle 9c at an appropriate interval. The result of applying the granular silver paste 6 in this manner is shown in FIG. This is the application shape described in FIG. 8 (a), which has a cross shape. The particles are applied in close proximity to each other, and immediately after the application, the adjacent particles are connected to each other to form a substantially X shape.

That is, the feature of the coating mechanism of the fourth embodiment is that the tip of the needle 9c rotates on a spherical surface with a certain distance between the tip of the needle 9c and the lead frame 3, and The granular silver paste 6 is injected from the tip of the needle 9c, and the granular silver paste 6 does not bridge the needle 9c and the lead frame 3. Regarding the mounting position of the dispenser 22a, the distance LU from the fulcrum to the spherical portion 32 is shorter than the distance LD from the fulcrum to the tip of the needle 9c. Therefore, the movement amount of the spherical portion 32 is smaller than the movement amount of the tip of the needle 9c, and the ratio thereof is LU / LD. That is, even if the movement amount of the tip of the needle 9c is large, the XY drive mechanism 27
The X and Y movements of can be smaller than that.

The operation and effects of the die bonder coating mechanism of the present invention described above are summarized below. At the time of application, a granular silver paste is ejected, and there is no liquid dripping at this time, and it is not necessary to slowly raise the dispenser after the end of ejection unlike the conventional dispenser. Also, the silver paste on the grains does not bridge the needle and the lead frame. Therefore, the silver paste does not pull the thread from the tip of the needle at the end of the application, and the two-step rising operation for cutting the silver paste drooping like a thread is not required unlike the conventional dispenser. That is, the dispenser does not require any vertical movement. Therefore, the coating operation can be performed at a higher speed than in the conventional case. In particular, if the form shown in Example 4 is adopted, the time for applying a complicated shape such as an X shape is about half that of the conventional one-stroke writing method, and the cycle time of the entire apparatus can be greatly shortened. it can. Further, in the case of the form shown in the fourth embodiment, the XY drive mechanism needs only a small amount because the XY drive amount of the XY drive mechanism is smaller than the needle tip movement amount. At the same time, the dispenser moves with little resistance through the spherical joint, so that only slight force is required to manipulate the bulb to move the dispenser. As a result, the conventional X
A high-rigidity and large-sized drive mechanism such as a Y table is not necessary. Also, as is the case with all embodiments, no mechanism is required to move the dispenser up and down. Considering this and the contents described in the above section, even in the form of the fourth embodiment, the coating mechanism portion can be made significantly smaller and lighter. At the same time, the manufacturing cost can be kept low.

Finally, some points will be supplemented. First, it relates to the second embodiment. Here, the form corresponding to the lead frame in which the plurality of lands are arranged orthogonally to the pitch feed direction has been described. However, some lead frames of this type have a plurality of lands arranged without being orthogonal to the pitch feed direction. However, if they are on a straight line, the slide unit may be installed by aligning the straight-ahead direction of the needle with the straight line.

Next, regarding the movement operation of the dispenser shown in the fourth embodiment, in the description so far,
The spherical portion provided on the upper portion of the dispenser is engaged with the XY plane operation portion of the XY drive mechanism. In other words, it took the form of a ball joint. However, even in other forms, the same effect can be exhibited. For example, a link mechanism corresponds to it. Also, the method of supporting the dispenser is not limited to the spherical joint. It is enough that the dispenser can move freely, with the fulcrum somewhere along the vertical center axis of the dispenser.

Further, regarding the dispenser mounting plate, it has been assumed that it does not move up and down in the above embodiments. This is one of the major features of the die bonder using the injection type dispenser, but considering the space between the needle and the lead frame, it is more convenient to have a structure that can be adjusted up and down to some extent. For example, install the dispenser mounting plate on the slide unit that moves up and down,
There is a structure in which the height is adjusted to an appropriate height with a micrometer and then fixed. However, during application, vertical movement is not necessary, let alone vertical drive mechanism using a motor.

Further, although the silver paste was selected as the bonding agent for the die in the above description, this is applicable not only to the silver paste but also to other paste-shaped bonding agents such as resin. Die bonders can have similar effects.

[0038]

As described above, in the case of the die bonder having the paste application mechanism of the present invention, since the granular silver paste is ejected from the dispenser, the dispenser is moved up and down when applying the silver paste. No need. Even with this, the silver paste does not drip or draw a thread from the tip of the needle. Therefore, the application time can be significantly shortened. Further, the dispenser is supported by a spherical joint partway, and the upper end of the dispenser can be moved in the XY plane, whereby the needle tip can be rotated on the spherical surface. If the granular silver paste is ejected during this spherical movement, the silver paste can be applied in a complicated shape to the land portion of the lead frame. At this time, the XY drive mechanism for moving the upper portion of the dispenser may be compact.
Therefore, like the conventional die bonder, the dispenser is
A large-scale driving mechanism for driving the YZ axes is not required, and the coating mechanism section can be significantly reduced in size and weight.

[Brief description of drawings]

FIG. 1 is a perspective view imagining how a silver paste is applied in a die bonder according to a first embodiment of the present invention.

FIG. 2 is a perspective view imagining how a silver paste is applied in a die bonder according to a second embodiment of the present invention.

FIG. 3 is a perspective view imagining how a silver paste is applied in a die bonder according to a third embodiment of the present invention.

FIG. 4 is a perspective view (partially broken display) showing an image of applying a silver paste in a die bonder according to a fourth embodiment of the present invention.

FIG. 5 (a) is a perspective view showing how the dispenser moves in the die bonder according to the fourth embodiment of the present invention;
(B) Front view (partial cross section)

FIG. 6 is a plan view showing a land portion of a lead frame coated with silver paste in the die bonder of the present invention.

FIG. 7 is a perspective view of a conventional die bonder, in which an image of a coating mechanism portion when applying one point to a land portion is imaged.

FIG. 8 is a plan view showing a state where silver paste is applied to a large land portion.

FIG. 9 is a perspective view of a conventional die bonder, which is an image of a coating mechanism unit for coating using a multi-type dispenser.

FIG. 10 is a perspective view of a conventional die bonder with a complex shape applied to a land portion with a single stroke applying silver paste.

FIG. 11 is a plan view illustrating a trajectory of a dispenser that moves on a land portion when a silver paste is applied with a single stroke in a conventional die bonder.

[Explanation of symbols]

1 Die Bonder 2 Rail 3 Lead Frame 4 Land 6 Silver Paste 7 Vertical Drive 8, 8a Dispenser 9, 9a, 9b, 9c Needle 11, 11a Motor 12, 12a Ball Screw 13 LM Guide 14, 14a, 14b Dispenser Mounting Plate 16 XY table 17 Guide rods 21,21a Mounting angles 22,22a Dispenser (used in the die bonder of the present invention) 23 Conducting wire 24 Slide unit 26 Slider 27 XY drive mechanism 28 X axis drive motor 29 Y axis drive motor 31 Spherical joint 32 Spherical part 33 Outer ring 34 Inner ring

─────────────────────────────────────────────────── --Continued from the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/52

Claims (2)

(57) [Claims] 1. In a die bonder for bonding a semiconductor die to a lead frame with a paste-like bonding agent, a horizontal plane XY is provided above a dispenser for ejecting the bonding agent in granular form.
A drive mechanism is arranged, and the dispenser is installed above the lead frame with the injection needle at the lower end and supported midway , and the XY drive mechanism is above the support portion.
And is supported by the drive of the XY drive mechanism.
The tip of the needle rotates on a spherical surface with the portion as a fulcrum, and when applying the bonding agent to the lead frame, the dispenser should inject a granular bonding agent to a predetermined position of the lead frame. A die bonder characterized by. Wherein in said dispenser, the distance from the support portion to the engaged portion of the XY driving mechanism, according to claim 1, wherein a shorter than the distance from the support portion to the injection needle tip Die bonder.