JP2559344B2 - Inner lead bonding equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to relates to <br/> Bonn Dinh grayed device of the inner lead to be used in production facilities of the semiconductor device using the carrier film.

[0002]

2. Description of the Related Art In a semiconductor device, a semiconductor element is generally attached to a die pad provided on a lead frame, and an external electrode of the semiconductor element and a terminal of the lead frame are connected to each other by wires, which are connected to a thermosetting resin such as epoxy resin. After packaging in, each terminal is cut and manufactured.

By the way, in recent years, along with the miniaturization and thinning of electronic equipment, the semiconductor devices used therefor are also mounted at a high density, so that the appearance of thin and small semiconductor devices is desired. In order to meet such a demand, a semiconductor element is provided in a device hole of a carrier film such as a polyimide film, and an electrode of the semiconductor element and an inner lead of the carrier film are directly connected to each other, and a liquid resin (for example, epoxy resin) is used. A semiconductor device in which a sealing material made of resin is printed or potted to be packaged has come into use.

FIG. 6 is a plan view for explaining a conventional semiconductor device using a carrier film, and FIG. 7 is an AA enlarged sectional view thereof. In the figure, reference numeral 1 denotes a device having holes 2, 2a, 2b, ... Having a larger area than the surface area of semiconductor elements 6, 6a, 6b ,. It is a carrier film. Reference numeral 3 denotes a large number of conductive patterns formed on the carrier film 1 and having a high conductivity such as copper and having a thickness of 3O to 4Oμm and a width of 5O to 3OOμm. It is the lead 3a. Reference numeral 5 is a sprocket hole for carrying the carrier film 1.

FIG. 2 is a schematic view showing an example of a bonding apparatus for bonding the inner leads 3a of the carrier film 1 to the electrodes of the semiconductor element 6, and FIG. 3 is an enlarged view of the main part thereof. In both figures, 7 is a C-shaped device body, and a bonding stage 8 having a built-in heater is provided in the lower front part thereof. Reference numeral 9 denotes a bonding head which is vertically slidably mounted along a guide 7a provided on the upper front side of the apparatus main body 7. A bonding tool 10 having a built-in heater is attached to the lower part so as to face the bonding stage 8. There is. Reference numeral 12 is an air cylinder for pressing down the bonding head 9. 13 is rotatably fixed to the main body 7 of the apparatus, and has a pulse motor 14 (previously, a frequency of 1 KH
z, one rotation of which is about 1OOO pulse) is used to drive the cam through the belt 15, and 16 is a lever whose center portion is rotatably pivoted to the apparatus main body 7. Is in sliding contact with the outer periphery of the cam 13, and the other end 18 is connected to the connecting portion 11 of the bonding head 9.

Next, the operation of the bonding apparatus having the above structure will be described. The semiconductor element 6 placed on the bonding stage 8 is positioned at a predetermined position by a positioning guide (not shown). On the other hand, the carrier film 1 guided by a tape rail (not shown) and fed by the sprocket in the direction perpendicular to the paper surface is stopped at the position where the device hole 2 reaches the semiconductor element 6 and is provided on the semiconductor element 6. The multiple electrodes 4 and the inner leads 3a are aligned with each other. At this time, the semiconductor element 6
Is heated by a heater built in the bonding stage 8. In this state, the pulse motor 14 is driven to drive the cam 1
3 is rotated, and the bonding head 9 is lowered through the lever 16 that is in sliding contact with this (lowering speed is about 5 cm / sec).
Then, the inner leads 3a are brought into contact with each other. Next, the bonding tool 10 heated by the heater built in by the air cylinder 12 is pressed down to heat and pressurize each inner lead 3a to form a predetermined angle, and each inner lead 3a is fused to each electrode. ,Connecting.

When the bonding is completed, the pressure applied to the bonding tool 10 by the air cylinder 12 is released, and the cam 13 is rotated to raise the bonding head 9. Then, the carrier film 1 is moved one frame, and the next semiconductor element 6 is moved to the bonding stage 8.
Is placed and bonding is performed in the same manner as above.

FIG. 4 shows another example of the bonding apparatus. A pinion 16a meshing with a rack 1la provided on the bonding head 9 is driven by a pulse motor 14 via a belt 15 to move the bonding head 9 up and down. The operation is similar to that of the device described with reference to FIG.

[0009]

When the inner lead of the carrier film is bonded to the electrode of the semiconductor element, when the bonding tool descends at a high speed and collides with the inner lead, the impact load is applied to the lower part of the electrode of the semiconductor element. A crack may occur in the formed oxide film, and a protrusion (bump) provided on the electrode may be crushed more than necessary to cause an edge short. further,
The impact may cause the bonding tool to bounce and cause a positional shift, which makes it impossible to reliably bond the electrode and the inner lead. In order to prevent such a problem, it is desirable that the speed at which the bonding tool makes contact with the inner leads be made as low as possible to minimize the impact load.

However, in the bonding apparatus constructed as described above, as shown in FIG. 5, the bonding tool abuts the inner lead at the speed V ₁ , and therefore the generation of impact load is unavoidable. Although it is possible to slow down the dropping speed of the bonding tool in order to reduce the impact, this cannot be adopted because it causes a significant decrease in productivity. Therefore, as shown in FIG. 2, a cam or the like is used to control the speed of the bonding tool, but there is a limit to that, and the above-mentioned various problems still occur.

[0011] The present invention has the above-mentioned problems has been made rather solve all, by lowering just before contact with rapid descent rate of the bonding tool to the inner lead, the inner which is adapted to greatly reduce the impact load It is intended to realize a lead bonding apparatus .

[0012]

SUMMARY OF THE INVENTION A bonding apparatus for an inner lead according to the present invention lowers a bonding tool at a high speed so that the speed of the O.D. 1-5. The motor for driving the bonding tool is controlled so as to sharply decrease it to Ocm / sec.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, most of the stroke of the bonding tool 9 is lowered at a high speed by controlling a pulse motor, and the impact load is stopped to a minimum by switching to a low speed immediately before contacting the inner lead 3a. It is the one.

[0014] According to an embodiment, the ball <br/> down loading tool stroke 50 mm, the frequency 30～40KHz, in about one rotation 4000 pulses, controlled the lowering speed by using a high resolution stepping motor. In this case, as shown in FIG. 1, of the 50 mm stroke of the bonding tool, 49 mm is lowered at a high speed of 20 cm / sec, and the encoder is fed back to control the rotation speed of the pulse motor. The remaining 1 mm is 0.5 cm / sec. When the bonding was carried out while descending at a low speed of sec, the semiconductor element was not affected by the impact load at all.

According to the results of the experiment, Table 1 shows the relationship between the speed at the time of contact of the bonding tool with the inner lead and the influence on the semiconductor element.

[0016]

[Table 1] As is clear from Table 1, the bonding tool is 0.1
It was found that contacting the inner leads at a speed of about 5.0 cm / sec had almost no effect on the semiconductor device.

[0017]

As described above in detail, according to the present invention, by controlling the motor for driving the bonding tool, most of the stroke of the bonding tool is lowered at a high speed, and the slight range of the remaining stroke is extremely reduced. Since it was lowered at a low speed, the impact on the inner leads could be almost eliminated. Therefore, the following remarkable effects can be obtained.

(1) Since the impact load is reduced by lowering the speed at which the bonding tool hits the inner lead, that is, the semiconductor element, the oxide film formed under the electrode of the semiconductor element is not cracked. .

(2) Since the lowering speed of the bonding tool is low, it does not bounce when hitting a semiconductor element. For this reason, it is possible to eliminate the conventional positional deviation caused by the bouncing of the bonding tool.

(3) Since the impact load is small, the bumps provided on the electrodes of the semiconductor element are not crushed more than necessary, and therefore edge short circuit does not occur.

(4) Since the descending speed of the bonding tool can be increased to about three times that of the conventional method, the bonding cycle time can be shortened and the productivity can be improved.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the operation of the present invention.

FIG. 2 is a side view showing an example of a bonding apparatus.

FIG. 3 is an enlarged front view of the main part.

FIG. 4 is a side view of another bonding apparatus.

FIG. 5 is a diagram showing a relationship between a descending speed and a position of a conventional bonding tool.

FIG. 6 is an explanatory view showing a manufacturing example of a semiconductor device using a carrier film.

FIG. 7 is an enlarged sectional view taken along line AA of FIG.

[Explanation of symbols]

 1: Carrier film 3a: Inner lead 6: Semiconductor element 7: Device body 8: Bonding stage 9: Bonding head 1O: Bonding tool 14: Pulse motor

Claims (2)

(57) [Claims] [1 claim: a stage for placing a semiconductor element, and an electrode on the semiconductor element mounted on the stage, the
The inner film of the carrier film aligned with the electrodes
The bonding tool for crimping the bonding tool, the motor for driving the bonding tool, and the lowering speed of the bonding tool are
Immediately before hitting, so that it becomes 0.1-5.0 cm / sec
Of the inner lead, characterized in that it comprises means for controlling said motor, at least
Bonding equipment. 2. The stage heats the semiconductor element.
A heater for heating is provided.
Inner lead bonding device described.