JP2004247670A - Semiconductor device manufacturing method and bonding apparatus used therein - Google Patents

Abstract

To stably perform ultrasonic die bonding while preventing a reduction in speed.
A bonding table for holding a wiring board is provided on an XY drive section of a bonding stage. A feed screw shaft device 43 that raises and lowers a lift base 44 by forward and reverse rotation of a motor 41 is interposed in the support frame 40, and a holder 46 is hung by a piston rod of an air cylinder device 45 installed on the lift base 44. ing. The left end of the vibrator 50 to which the bonding tool 52 is attached at the right end is fixed to the support portion 48 of the holder 46, and the right end of the vibrator 50 is slidably supported in the air floating bearing 49 in the axial direction. .
[Effect] A pressing force can be applied from directly above the bonding tool attached to the right end of the vibrator, and the pressing force can be applied to the bonding tool without losing the vibration energy of the vibrator, so that the chip bumps can be stably mounted on the land of the wiring board. Can be joined together.
[Selection diagram] FIG.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor device manufacturing technique, in particular, a semiconductor chip (a chip in which an integrated circuit including an active element, a passive element, and a circuit for electrically connecting the active element and the passive element is formed; hereinafter, referred to as a chip). 2. Description of the Related Art A bonding technique for mechanically connecting a carrier to a carrier (bonding: a mechanical connection that is not in close contact with an atomic force and is hereinafter referred to as bonding) is used, for example, to manufacture a memory module. And effective technology.
[0002]
[Prior art]
For example, as a bonding device for bonding a chip to a carrier of a memory module, an ultrasonic flip chip bonding device (hereinafter, referred to as an ultrasonic die bonder) is becoming widespread. As a support structure of a vibrator for energizing ultrasonic vibration used in an ultrasonic die bonder, a cantilever structure for supporting one end of the vibrator (for example, see Patent Document 1) and both ends of the vibrator are provided. There is a two-sided supporting structure (for example, see Patent Document 2).
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-261121 [Patent Document 2]
Japanese Patent No. 3290632 [0004]
[Problems to be solved by the invention]
However, in the cantilever type ultrasonic die bonder, the target product is limited because the applied load cannot be set to a large value. There is a problem that bonding becomes unstable.
[0005]
On the other hand, the double-sided ultrasonic die bonder has a problem that the bonding speed is reduced due to an increase in weight.
[0006]
An object of the present invention is to provide a semiconductor device manufacturing technique capable of performing stable bonding while avoiding a decrease in bonding speed.
[0007]
The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.
[0008]
[Means for Solving the Problems]
The outline of a typical invention disclosed in the present application will be described as follows.
[0009]
That is, a bonding device that urges ultrasonic vibration to a contact portion between a semiconductor chip and a carrier by a vibrator to join the contact portion,
One end of the vibrator is supported by a non-contact bearing.
[0010]
According to the above-described means, since one end of the vibrator is supported by the non-contact bearing, a pressing force is applied from directly above the bonding tool attached to one end of the vibrator in a cantilever structure. Therefore, it is possible to set a large pressing force, and it is possible to prevent the flatness from being deviated due to the inclination. Furthermore, since bonding can be performed without losing vibration energy in the vibration direction of the vibrator, the bonding speed can be increased.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0012]
In the present embodiment, the method for manufacturing a semiconductor device according to the present invention is configured as a method for manufacturing a memory module, and the chip 10 shown in FIG. The die bonding step of bonding to the wiring board 20 as described above is performed by the ultrasonic die bonder 30 shown in FIGS.
[0013]
The chip 10 shown in FIG. 1 includes a substrate 11 formed in a rectangular flat plate shape, and a RAM circuit is formed on a first main surface 12 of the substrate 11 which is a main surface on the active area side. It is rare. A plurality of electrode pads 13 are formed on the first main surface 12 of the substrate 11 so as to be aligned in a row at the ends of both long sides, and a passivation film (passivation film) is formed on the first main surface 12 of the chip 10. A film 14 is entirely attached with each electrode pad 13 exposed. Each electrode pad 13 is provided with a bump 15 made of a gold material (gold or gold alloy), and the head of each bump 15 projects from the upper surface of the passivation film 14. The bump 15 is formed in a substantially hemispherical shape by a wire bonding technique using a gold wire.
[0014]
The wiring board 20 shown in FIG. 2, which is the other work of the ultrasonic die bonder 30, includes a board body (hereinafter, referred to as a body) 21. The body 21 is made of an insulating material such as a glass impregnated epoxy resin or ceramic. Used to form a rectangular flat plate. The short side of the main body 21 is set to be larger than the long side of the chip 10, and the long side of the main body 21 is set so that even if the seven chips 10 are mounted side by side on the surface, a margin still remains. A large number of external terminals 22 are formed parallel to each other at the end of one long side of both main surfaces of the main body 21. In a region other than the external terminal group 22 on the front side main surface of the main body 21, seven substantially rectangular bonding areas 23 virtually formed are set at predetermined intervals, and each bonding area 23 has a long side direction. It is orthogonal to a center line parallel to the long side of the main body 21. In each bonding area 23, a plurality of lands 24 for mechanically and electrically connecting the chip 10 are formed in a pair of rows on the left and right sides, respectively. Each of the external terminals 22 is insulated from each other by electrical wiring (not shown).
[0015]
As shown in FIG. 3, the ultrasonic die bonder 30 includes a machine base 31, and a bonding stage 32 is set at a substantially central portion of the machine base 31. An XY drive unit 33 is provided on the bonding stage 32, and a bonding table 34 for holding the wiring board 20 is provided on the XY drive unit 33. The XY drive unit 33 is configured to move the bonding table 34 in the X and Y directions which are vertical and horizontal in the horizontal plane and to rotate in the Θ direction which is a rotation angle about a reference point in the horizontal plane.
[0016]
A support frame 40 is erected on the machine base 31, and a motor 41 is installed vertically downward on the support frame 40, and a pair of guide poles 42, 42 are arranged on both sides of the motor 41. Have been drooping. A lift base 44 is erected between the guide poles 42 and 42 so as to be able to move up and down freely. A lift base 44 is provided between the lift base 44 and the output shaft of the motor 41 by forward and reverse rotation of the output shaft of the motor 41. The feed screw shaft device 43 for raising and lowering the shaft is interposed. An air cylinder device 45 is installed vertically downward on the lift base 44, and a holder 46 is suspended from a lower end of a piston rod 45 a of the air cylinder device 45. A pair of guide shafts 47, 47 are provided on both sides of the piston rod 45a on the upper surface of the holder 46 so as to project vertically upward, and the two guide shafts 47, 47 are slidably fitted into the two guide poles 42, 42. Have been.
[0017]
At the left end of the holder 46, a support portion 48 projects vertically downward, and at a substantially central portion of the holder 46, an air floating bearing 49 as a non-contact bearing projects vertically downward. One end of a vibrator 50 arranged so as to extend in the horizontal direction in the horizontal plane is fixed to the support portion 48, and as shown in FIG. Is inserted and supported slidably in the axial direction. An oscillator 51 is coaxially arranged and coupled to the left end face of the oscillator 50. The oscillator 51 is constructed by an energy converter such as a piezoelectric element or a magnetostrictive element that converts electric energy into mechanical energy, and generates a longitudinal wave having a predetermined frequency by electric power supplied from an ultrasonic generator (not shown). It is configured to generate and output ultrasonic vibration. The vibrator 50 has a length of one wavelength of a resonance frequency that resonates with the ultrasonic vibration from the oscillator 51, and the support portion 48 is located at the point of maximum vibration amplitude. A bonding tool 52 is attached vertically downward at the maximum vibration amplitude point at the tip of the vibrator 50. As shown in FIG. 4, a suction port 53 for holding the chip 10 by vacuum suction is formed on the lower end surface of the bonding tool 52, and a suction path 54 is connected to the suction port 53.
[0018]
On one side of the bonding stage 32 of the machine base 31, a Y-axis robot 61 is laid in the Y direction, and the Y-axis robot 61 is configured to reciprocate the X-axis robot 62 in the Y direction. The X-axis robot 62 is configured to reciprocate the image recognition device 63 installed at its front end in the X direction. The image recognition device 63 is configured to recognize the characteristic pattern on the upper surface of the wiring board 20 held by the bonding table 34 and the characteristic pattern of the chip 10 held by the bonding tool 52.
[0019]
Next, the die bonding step of the method of manufacturing a memory module according to one embodiment of the present invention using the ultrasonic die bonder having the above configuration will be described.
[0020]
As shown in FIG. 1, the wiring board 20, which is one of the works of the ultrasonic die bonder 30, is held on the bonding table 34 with the lands 24 facing upward. As shown in FIG. 4, the chip 10, which is the other work, is held by the bonding tool 52 with the bump 15 facing downward by the suction force applied to the suction port 53 by the bonding stage 32. And is opposed to the wiring board 20.
[0021]
When the chip 10 of the bonding tool 52 is opposed to the bonding area 23 of the wiring board 20 on the bonding stage 32, the Y-axis robot 61 advances the X-axis robot 62, as shown by the imaginary line in FIG. Then, the image recognition device 63 is inserted between the upper surface of the wiring board 20 and the chip 10. The image recognition device 63 recognizes the characteristic pattern of the bonding area 23 of the wiring board 20 and the characteristic pattern of the chip 10 held by the bonding tool 52, and thereby the land 24 on the upper surface of the wiring board 20 and the chip 10 of the bonding tool 52. Are aligned with the bumps 15 of FIG. When the positioning is completed, the image recognition device 63 is returned to the original position by the Y-axis robot 61.
[0022]
When the positioning based on the image recognition device 63 is completed, the bonding table 34 is moved by the XY drive unit 33, the lift base 44 is lowered via the feed screw shaft device 43 by the forward rotation of the motor 41, and the air cylinder device 45 is moved. The bonding tool 52 is lowered by the lowering of the holder 46 due to the extension of the piston rod 45a, and the bumps 15 of the chip 10 are pressed against the lands 24 of the bonding area 23 of the wiring board 20. At the same time, the oscillator 51 oscillates and the oscillator 50 urges the ultrasonic vibration to the contact portion between the bump 15 of the chip 10 and the land 24 of the wiring board 20. The bumps 15 of the chip 10 and the lands 24 of the wiring board 20 are joined by the pressing force and the urging force of the ultrasonic vibration. At this time, since each land 24 of the bonding area 23 of the wiring board 20 and each bump 15 of the chip 10 of the bonding tool 52 are aligned in advance, the chip 10 of the bonding tool 52 is Bonded properly.
[0023]
By repeating the above operations, the chip 10 is sequentially bonded to the wiring board 20 by the bonding tool 52, and the memory module 25 shown in FIG. 5 is manufactured. In the ultrasonic die bonder 30, when the chip 10 is bonded to the wiring board 20, the bonded wiring board 20 is discharged from the bonding table 34, and the next wiring board 20 is automatically supplied to the bonding table 34. come.
[0024]
According to the embodiment, the following effects can be obtained.
[0025]
1) By supporting the tip of the vibrator with an air floating bearing, it is possible to apply a pressing force from directly above the bonding tool attached to the tip of the vibrator in a cantilever structure. Can be set large, and the flatness of the ultrasonic die bonder having the conventional cantilever structure can be prevented from being deteriorated due to the inclination of the vibrator. As a result, ultrasonic die bonding can be performed stably and appropriately even for a product (chip) requiring a large pressing force.
[0026]
2) By supporting the tip of the vibrator by an air floating bearing, the amount of deflection of the tip due to the vertical load can be reduced without losing vibration energy in the vibrating direction of the vibrator, and the bonding speed can be reduced by increasing the weight. Since the drop can be prevented, the bumps of the chip can be efficiently subjected to ultrasonic die bonding to the lands of the wiring board.
[0027]
3) Ultrasonic die bonding performance equivalent to that of the double-sided structure can be obtained with the cantilever structure, and the manufacturing cost can be reduced as compared with an ultrasonic die bonder having the same double-sided structure.
[0028]
Although the invention made by the present inventor has been specifically described based on the embodiment, the present invention is not limited to the above embodiment, and various changes can be made without departing from the gist of the invention. Needless to say.
[0029]
For example, the air levitation bearing that supports the tip of the vibrator may be configured so as not to receive the lower surface of the vibrator as shown in FIG. That is, the air levitation bearing 49A may have a structure capable of supporting a reaction applied to the bonding tool 52 during ultrasonic die bonding.
[0030]
The non-contact bearing that supports the tip of the vibrator is not limited to the air levitation bearing, but may be a magnetic levitation bearing 49B as shown in FIG.
[0031]
In the above description, the manufacturing technology of the memory module, which is the application field in which the invention made by the present inventor is the background, has been described. However, the present invention is not limited thereto, and the manufacturing of the semiconductor device using the ultrasonic vibration is not limited thereto. Applicable to all technologies.
[0032]
【The invention's effect】
The effect obtained by the representative one of the inventions disclosed in the present application will be briefly described as follows.
[0033]
By supporting the tip of the vibrator with a non-contact type bearing, it is possible to apply a pressing force from directly above the bonding tool attached to the tip of the vibrator even though it has a cantilever structure. It can be set large, and it is possible to prevent the degree of flatness from being deviated due to the inclination of the transducer in the case of a conventional cantilever type ultrasonic die bonder. Furthermore, since bonding can be performed without losing vibration energy in the vibration direction of the vibrator, the bonding speed can be increased.
[Brief description of the drawings]
FIGS. 1A and 1B show respective chips used in a method for manufacturing a memory module according to an embodiment of the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line bb. .
2 (a) is a partially omitted plan view, FIG. 2 (b) is an enlarged plan view of a main part, and FIG. 2 (c) is a sectional view taken along line cc of FIG. 2 (b). is there.
FIG. 3 is a front view showing an ultrasonic die bonder according to an embodiment of the present invention.
4 (a) is a front sectional view, and FIG. 4 (b) is a side sectional view taken along line bb in FIG. 4 (a).
5A and 5B show a memory module, wherein FIG. 5A is a partially omitted plan view, FIG. 5B is an enlarged plan view of a main part, and FIG. 5C is a cross-sectional view taken along line cc of FIG. .
6A and 6B show another embodiment of the air levitation bearing, in which FIG. 6A is a front sectional view, and FIG. 6B is a side sectional view along line bb of FIG. 6A.
7A and 7B show an embodiment of a magnetic levitation bearing, in which FIG. 7A is a front sectional view, and FIG. 7B is a side sectional view taken along the line bb of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Chip, 11 ... Substrate, 12 ... First principal surface, 13 ... Electrode pad, 14 ... Passivation film, 15 ... Bump, 20 ... Wiring board, 21 ... Substrate body (body), 22 ... External terminal, 23 ... Bonding area, 24 land, 25 memory module (semiconductor device), 30 ultrasonic die bonder, 31 machine stand, 32 bonding stage, 33 XY drive unit, 34 bonding table, 40 support frame, 41 Motor 42 guide rod 43 feed screw shaft device 44 lift base 45 air cylinder device 45a piston rod 46 holder 47 guide shaft 48 support portion 49, 49A air floating Bearing (non-contact type bearing), 49B: magnetic levitation bearing (non-contact type bearing), 50: vibrator, 51: oscillator, 52 ... Down loading tool, 53 ... suction port 54 ... suction passage, 61 ... Y-axis robot, 62 ... X-axis robot, 63 ... image recognition apparatus.

Claims (5)

A method of manufacturing a semiconductor device, comprising: a step of applying ultrasonic vibration to a contact portion between a semiconductor chip and a carrier by a vibrator to join the contact portion, wherein the vibrator has a non-contact bearing at one end thereof. Energizing the ultrasonic vibration to the contact portion in a state supported by the semiconductor device. A bonding apparatus for applying ultrasonic vibration to a contact portion between a semiconductor chip and a carrier by a vibrator to join the contact portion,
A bonding apparatus, wherein one end of the vibrator is supported by a non-contact bearing. The bonding apparatus according to claim 2, wherein the non-contact bearing is configured to support at least a portion of the vibrator opposite to the contact portion. The bonding device according to claim 2, wherein the non-contact type bearing is configured by an air floating bearing. 4. The bonding apparatus according to claim 2, wherein the non-contact type bearing is constituted by a magnetic levitation bearing.

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