JPH1154678A - Ultrasonic bonder for manufacturing semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device which can reduce the manufacturing cost of an ultrasonic bonder for manufacturing a semiconductor device, and prevent generation of troubles due to burrs. SOLUTION: In this ultrasonic bonder for manufacturing a semiconductor device, flat pressure surfaces 2A, 3A are installed on a stage block 2 and an ultrasonic horn 3, and stop ribs 2a, 3a which abut against the peripheral parts of a lead frame 10 and a heat radiating plate 20 and regulate movement, are installed. The manufacturing method of a semiconductor device performs bonding of the lead frame 10 and the heat radiating plate 20 by using the ultrasonic bonder for manufacturing a semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic bonding machine for manufacturing a semiconductor device and a method for manufacturing a semiconductor device using the ultrasonic bonding machine.

[0002]

2. Description of the Related Art When a semiconductor device having a heat sink is manufactured, an ultrasonic bonding machine A as shown in FIG. 8 is used for joining a lead frame and a heat sink. This ultrasonic bonding machine A
Has a stage block B fixedly installed and an ultrasonic horn C connected to a generator (oscillator) not shown, and a lead frame is set at a predetermined position of a heat sink H set on the stage block B. (Die pad)
L on the lead frame L by the ultrasonic horn C.
Is pressed against the heat radiating plate H, and the lead frame L and the heat radiating plate H are joined by applying a horizontal ultrasonic wave following the joint surface between the heat radiating plate H and the lead frame L.

[0003]

By the way, in the ultrasonic bonding machine A described above, when ultrasonic waves are applied to the pressing surfaces of the stage block B and the ultrasonic horn C, respectively, the heat radiating plate H and the lead frame L are moved. As shown in FIG. 9, pyramid-shaped protrusions D are arranged so as not to slip. For this reason, in the conventional ultrasonic bonding machine A, the manufacturing thereof requires a redundant processing time for forming the above-mentioned large number of convex portions D, D..., Thereby increasing the manufacturing cost of the ultrasonic bonding machine itself. In addition, there is a disadvantage that the production cost of the semiconductor device is increased. The present invention has been made in view of the above circumstances, and has as its object to provide an ultrasonic bonding machine for manufacturing a semiconductor device, which can reduce the manufacturing cost as much as possible.

On the other hand, pyramidal projections formed on the pressing surfaces of the stage block B and the ultrasonic horn C are formed on the surfaces of the heat radiating plate H and the lead frame L joined by the ultrasonic bonding machine A described above. Due to D, D, a large number of minute concave portions such as dimples in the stamping process are formed with many burrs. Therefore, FIG.
As shown in FIG. 0A, in the semiconductor device E of the type in which the heat sink H is built in the package P, the package P is easily cracked from the tip of the burr Ha in the heat sink H, and the reliability after molding is lowered. Inconvenience. In addition, as shown in FIG.
In the semiconductor device F of the type exposed to the outside, when attached to an external heat sink (not shown), the burr Ha prevents the heat sink H from being in close contact with the external heat sink.
There was a problem that the rated output could not be obtained due to an increase in thermal resistance. The present invention has been made in view of the above circumstances, and has as its object to provide a method of manufacturing a semiconductor device capable of preventing the occurrence of inconvenience due to burrs.

[0005]

In the ultrasonic bonding machine for manufacturing a semiconductor device according to the present invention, the pressing surfaces of the stage block and the ultrasonic horn are made smooth surfaces following the surfaces of the heat sink and the lead frame. At the same time, when ultrasonic waves are applied by the ultrasonic horn, stopper ribs that contact the heat sink and the peripheral edge of the lead frame to regulate the movement of the heat sink and the lead frame with respect to the stage block and the ultrasonic horn are provided. The above object is achieved by providing the sonic horn.

In the method of manufacturing a semiconductor device according to the present invention, the above-described ultrasonic bonding machine for manufacturing a semiconductor device according to the present invention is used to bond a heat sink and a lead frame, which are constituent elements of a semiconductor device. The above purpose is achieved by implementing.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments. As shown in FIGS. 1 to 4, an ultrasonic bonding machine 1 for manufacturing a semiconductor device according to the present invention.
Has a stage block 2 which is fixedly installed and an ultrasonic horn 3 connected to a generator (oscillator) not shown.

On the other hand, a method of manufacturing a semiconductor device according to the present invention uses a lead frame 10 and a heat sink 20 as shown in FIG.
The lead frame 10 has a rectangular die pad 11 located at the center, a large number of inner leads 12, 12,..., And the like. It is composed of a plate having a larger rectangular shape.

As shown in FIGS. 1 and 2, the stage block 2 of the ultrasonic bonding machine 1 for manufacturing a semiconductor device has a pressing surface 2A on which a heat radiating plate 20 is placed. It is constituted by a smooth surface following the surface of the plate 20. The stage block 2 has stopper ribs 2a, 2a, 2a, and 2a protruding from the stage block 2 so as to face the respective peripheral portions of the heat radiating plate 20 placed on the pressing surface 2A.

On the other hand, an ultrasonic horn 3 is disposed above the stage block 2 so as to be able to move up and down. As shown in FIGS. 1 and 3, the ultrasonic horn 3 has a die pad 11 of a lead frame 10 attached thereto. Is provided, and the pressing surface 3A is constituted by a smooth surface following the surface of the die pad 11.

The ultrasonic horn 3 has a pressing surface 3
Stopper ribs 3a, 3a, 3a, 3a are formed so as to protrude so as to face the respective peripheral portions of the die pad 11 in contact with A.

As is apparent from FIG. 5, a gap is provided between each edge of the die pad 11 in the lead frame 10 and each of the inner leads 12, 12,..., And the stopper rib 3a of the ultrasonic horn 3 is provided. Are formed in such a manner as to enter the gaps, respectively, and appropriate gaps are provided between the adjacent stopper ribs 3a, 3a to avoid the support bars 13, 13,... Of the lead frame 10.

The die pad 11 of the lead frame 10 is provided by the ultrasonic bonding machine 1 for manufacturing a semiconductor device having the above-described configuration.
In the step of bonding the heat sink 20 and the heat sink 20 to each other, the heat sink 20 is first placed on the pressing surface 2 </ b> A of the stage block 2.

Next, after positioning the lead frame 10 with respect to the stage block 2 and placing the die pad 11 at a predetermined position on the heat sink 20, the ultrasonic horn 3 is lowered to place the ultrasonic horn on the surface of the die pad 11. Then, the die pad 11 and the heat sink 20 are pressed against each other.

Thereafter, the ultrasonic horn 3 applies a horizontal ultrasonic wave (amplitude: 5 to 12 μm) following the joint surface between the die pad 11 and the heat radiating plate 20, and vibrates the die pad 11 with respect to the heat radiating plate 20. By doing so, the die pad 11 and the heat sink 20 are joined to each other.

Here, the pressing surface 2A of the stage block 2
And the pressing surface 3A of the ultrasonic horn 3 are both formed as smooth surfaces, so that the outer surfaces of the die pad 11 and the heat radiating plate 20 pressed by the stage block 2 and the ultrasonic horn 3 have burrs. Etc. are not formed.

Further, when ultrasonic waves in the horizontal direction are applied by the ultrasonic horn 3, the peripheral edge of the heat radiating plate 20 comes into contact with the stopper block 2a of the stage block 2, and the movement of the heat radiating plate 20 with respect to the stage block 2 is restricted. At the same time, the peripheral edge of the die pad 11 abuts against the stopper block 3a of the ultrasonic horn 3, and the movement of the die pad 11 with respect to the ultrasonic horn 3 is restricted.
1 and the heat radiating plate 20 are surely relatively moved by the applied horizontal ultrasonic vibration.

As described above, in the ultrasonic bonding machine 1 for manufacturing a semiconductor device, the pressing surface 2A of the stage block 2 and the pressing surface 3A of the ultrasonic horn 3 are each constituted by a smooth surface, while the pressing surface 2A is The stopper rib 2a formed and the stopper rib 3 formed on the pressing surface 3A
a, the stage block 2 and the ultrasonic horn 3
The movement of the heat radiating plate 20 and the die pad 11 is restricted.

For this reason, as shown in FIG. 8, in order to restrict the movement of the heat radiating plate H and the lead frame (die pad) L with respect to the stage block B and the ultrasonic horn C, a large number of convex portions D, D. Compared with the conventional ultrasonic bonding machine A for manufacturing a semiconductor device, the ultrasonic bonding machine 1 for manufacturing a semiconductor device described above has a smooth surface as a pressing surface and several ridges as a stopper block. Is formed, so that the processing becomes easy and the manufacturing cost of the ultrasonic bonding machine itself can be suppressed.

.. Between the stopper ribs 2a, 2a... Of the stage block 2 and the respective peripheral edges of the heat sink 20, and between the stopper ribs 3a, 3a. Appropriate clearances are provided between the stage block 2 and the ultrasonic horn 3 so that the heat radiating plate 20 and the die pad 11 can be set smoothly, and these clearances apply ultrasonic vibration. At this time, the die pad 11 and the radiator plate 20 can be moved relative to each other in a manner that allows the relative movement between the die pad 11 and the heat sink 20 in accordance with the amplitude of the ultrasonic wave applied by the ultrasonic horn 3.
It is set appropriately within the range of μm.

As described above, after bonding the die pad 11 of the lead frame 10 and the heat sink 20 using the ultrasonic bonding machine 1 for manufacturing a semiconductor device, the chip G is attached to the die pad 11.
Mounting process, chip G and each inner lead 12, 1
2, a resin molding step, and a separation step from the lead frame 10 to complete the semiconductor device 100 as shown in FIG. 6 or the semiconductor device 200 as shown in FIG.

Here, the ultrasonic bonding machine 1 for manufacturing semiconductor devices.
By bonding the die pad 11 and the heat radiating plate 20 by using, a slight abrasion is observed on the outer surfaces of the die pad 11 and the heat radiating plate 20, but many burrs are not formed. .

For this reason, as shown in FIG. 6, a semiconductor device 10 of the type in which the heat sink 20 is built in the package P is used.
In the case of 0, the occurrence of cracks due to burrs on the heat sink is prevented beforehand, and the reliability after molding is greatly improved.

As shown in FIG. 7, a semiconductor device 20 of the type in which the heat sink 20 is exposed outside the package P is provided.
In the case of 0, since the outer surface of the heat sink 20 is smooth, when mounted on an external heat sink (not shown), the external heat sink and the heat sink 20 are in close contact with each other, and a sufficient cooling effect can be obtained. Become.

Further, after the die pad 11 and the heat sink 20 are joined, even when the chip G is mounted on the die pad 11, the chip G is securely attached to the die pad 11 because the outer surface of the die pad 11 is smooth. It can be mounted on

As described above, according to the method of manufacturing a semiconductor device in which the die pad 11 and the heat sink 20 are bonded using the above-described ultrasonic bonding machine 1 for manufacturing a semiconductor device,
Since burrs do not occur on the outer surfaces of the die pad 11 and the heat radiating plate 20 joined to each other, it is possible to prevent various inconveniences caused by the burrs from occurring, and to manufacture a high-quality semiconductor device. Becomes possible.

In the ultrasonic bonding machine for manufacturing a semiconductor device shown in FIGS. 1 to 4, a heat sink is mounted on a stage block and a die pad is vibrated by an ultrasonic horn. Conversely, it is also possible to mount the die pad on the stage block and vibrate the heat sink with the ultrasonic horn.

[0028]

As described above, in the ultrasonic bonding machine for manufacturing a semiconductor device according to the present invention, the pressurizing surfaces of the stage block and the ultrasonic horn are made smooth by following the surfaces of the heat sink and the lead frame. Face and
When ultrasonic waves are applied by the ultrasonic horn, stopper ribs that contact the heat sink and the peripheral edge of the lead frame to restrict the movement of the heat sink and the lead frame with respect to the stage block and the ultrasonic horn, and the stage block and the ultrasonic horn. Is provided. According to the above configuration, as means for restricting movement of the heat sink and the lead frame with respect to the stage block and the ultrasonic horn,
The stage block and the ultrasonic horn can be easily processed as compared with the conventional ultrasonic bonding machine that has formed a large number of convex portions, and according to the ultrasonic bonding machine for manufacturing a semiconductor device according to the present invention, , It is possible to reduce the manufacturing cost of the device itself.

Further, in the method of manufacturing a semiconductor device according to the present invention, the pressing surfaces of the stage block and the ultrasonic horn may be smooth surfaces following the surfaces of the heat radiating plate and the lead frame, and the ultrasonic When ultrasonic waves are applied by the horn, the stopper ribs that contact the heat radiating plate and the peripheral edge of the lead frame to regulate the movement of the heat radiating plate and the lead frame with respect to the stage block and the ultrasonic horn, Using an ultrasonic bonding machine for manufacturing a semiconductor device provided on the block and the ultrasonic horn, the laminated heat sink and the lead frame are pressed by the stage block and the ultrasonic horn, and the ultrasonic wave is applied. By applying ultrasonic waves with a horn, the heat sink and the And bonding the lead frame to each other. According to the above configuration, burrs do not occur on the outer surfaces of the lead frame and the heat sink joined to each other. Therefore, in the method of manufacturing a semiconductor device according to the present invention, various inconveniences caused by burrs are prevented. This can be prevented beforehand, and a high-quality semiconductor device can be manufactured.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an ultrasonic bonding machine for manufacturing a semiconductor device according to the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG. 1 showing a main part of the stage block.

FIG. 3 is a sectional view taken along line III-III of FIG. 1 showing a main part of the ultrasonic horn.

FIG. 4 is a conceptual diagram showing an ultrasonic bonding machine for manufacturing a semiconductor device according to the present invention.

FIG. 5 is a plan view showing a heat sink and a lead frame which constitute the semiconductor device.

FIG. 6 is a conceptual cross-sectional view showing a semiconductor device manufactured by using the ultrasonic bonding machine for manufacturing a semiconductor device according to the present invention.

FIG. 7 is a conceptual cross-sectional view showing a semiconductor device manufactured by using the ultrasonic bonding machine for manufacturing a semiconductor device according to the present invention.

FIG. 8 is a conceptual diagram showing a conventional ultrasonic bonding machine for manufacturing a semiconductor device.

FIG. 9 is a bottom view of a main part of the ultrasonic horn.

10A and 10B are conceptual cross-sectional views showing a semiconductor device manufactured by using a conventional ultrasonic bonding machine for manufacturing a semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ultrasonic bonding machine for semiconductor device manufacture, 2 ... Stage block, 2A ... Pressing surface, 2a ... Stopper rib, 3 ... Ultrasonic horn, 3A ... Pressing surface, 3a ... Stopper rib, 10 ... Lead frame, 11 ... Die pad, 20 ... heat sink, 100, 200 ... semiconductor device.

Claims (2)

[Claims] 1. A stage block and an ultrasonic horn, wherein a laminated heat sink and a lead frame are pressed by the stage block and the ultrasonic horn, and the vibration direction of the heat sink is changed by the ultrasonic horn. An ultrasonic bonding machine for manufacturing a semiconductor device for bonding the heat sink and the lead frame to each other by applying ultrasonic waves along a bonding surface between the stage block and the lead frame. Each pressing surface of the horn is a smooth surface following the surface of the heat radiating plate and the lead frame, and when the ultrasonic horn is applied to the stage block and the ultrasonic horn by the ultrasonic horn, the heat is radiated. The stage block and the supersonic are brought into contact with a plate and a peripheral portion of the lead frame. The heat dissipation plate and ultrasonic bonding machine for semiconductor device fabrication that characterized in that a stopper rib for restricting the movement of the lead frame relative to the horn. 2. A method of manufacturing a semiconductor device, which requires a joining step between a lead frame and a heat sink, wherein respective pressing surfaces of a stage block and an ultrasonic horn are imitated on surfaces of the heat sink and the lead frame. Along with the smooth surface, when ultrasonic waves are applied by the ultrasonic horn, the ultrasonic horn comes into contact with the periphery of the heat sink and the lead frame, and the heat sink and the lead frame with respect to the stage block and the ultrasonic horn. Using an ultrasonic bonding machine for manufacturing a semiconductor device in which a stopper rib for restricting movement is provided on the stage block and the ultrasonic horn, the laminated heat sink and the lead frame are connected to the stage block and the ultrasonic horn. And pressurize, and apply ultrasonic waves by the ultrasonic horn. The Rukoto method of manufacturing a semiconductor device characterized by bonding the aforementioned heat radiating plate and the lead frame to each other.