JP3244664B2 - Ultrasonic vibration bonding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a metal member to be joined provided on a base fragile to the impact of a first member and a metal member to be joined of a second member. The base part is on the bonding action part side of the resonator, and the second member is on the pedestal side. The first member and the second member are pressed and sandwiched between the resonator and the pedestal, and transmitted to the resonator from the vibrator. The present invention relates to an ultrasonic vibration joining apparatus for joining a joined portion of a first member and a joined portion of a second member by ultrasonic vibration.

[0002]

2. Description of the Related Art Conventionally, an IC chip called a flip chip or a bare chip of a semiconductor device or an L chip called a BGA has been used.
It is well known that an ultrasonic vibration bonding apparatus is used when an SI package is surface-mounted on a circuit board. that is,
A bump such as gold or solder provided on the surface of the IC chip or LSI package and a bump such as gold or solder provided on the surface of the circuit board are superimposed, and the base of the IC chip or LSI package is subjected to ultrasonic vibration. The circuit board is located on the side of the joining action part of the resonator in the joining apparatus, the circuit board is the receiving side of the ultrasonic vibration joining apparatus, and the IC chip or LSI package and the circuit board are pressed and sandwiched between the resonator and the receiving stand. .
In this state, the portion to be joined of the first member and the portion to be joined of the second member are joined by the ultrasonic vibration transmitted from the vibrator of the ultrasonic vibration joining device to the resonator.

[0003]

However, the first member, such as an IC chip or an LSI package, has a form in which a base portion made of a ceramic or the like, which is brittle against impact, has a metal joint to be a pump. Further, the thickness of the first and second members has a variation within a tolerance range. Alternatively, the parallelism between the joining action part and the cradle may be out of order. Due to these factors, during joining, the base is not damaged by the impact of ultrasonic waves, or the base is not damaged, but the first and second parts are not damaged.
In some cases, defective joining occurred between the joined portions of the members.

Accordingly, the present invention absorbs variations in the thickness inherent in the first and second members and deviations in the parallelism between the joining portion and the pedestal to prevent breakage of the base of the first member and prevent the first member from being damaged. It is an object of the present invention to provide an ultrasonic vibration bonding apparatus capable of preventing defective bonding between the parts to be bonded in the second member.

[0005]

According to the first aspect of the present invention, the metal member to be bonded provided on the base member which is vulnerable to the impact of the first member and the metal member to be bonded of the second member are formed. At the same time, the first member and the second member are pressed and sandwiched between the resonator and the pedestal, with the base of the first member being on the side of the joint acting portion of the resonator and the second member being on the pedestal side. The ultrasonic vibration transmitted from the vibrator to the resonator causes the portion to be joined of the first member and the second
An ultrasonic vibration bonding apparatus for bonding a member to be bonded to a member includes a buffer member sandwiched between a bonding portion of the resonator and a base of the first member. Claim 2
According to the invention, the cushioning member according to the first aspect is provided in the joining operation portion. According to a third aspect of the present invention, the impact member according to the first aspect is provided on the first member.

[0006]

1 and 2 show a first embodiment of the present invention. FIG. 1 shows a cross section of an ultrasonic vibration bonding apparatus cut in a longitudinal direction, and FIG. The part enclosed by is shown enlarged.

Referring to FIG. 1, an ultrasonic vibration bonding apparatus will be described. The apparatus main body 1 includes a work space 2 which is opened forward and left and right at a lower portion on the front side. An air cylinder 3 as a pressurizing mechanism is provided inside the apparatus main body 1 which partitions the upper part of the work space 2. A holder 4 is mounted on a lower end of a piston rod 3 a projecting below the air cylinder 3 via a connecting member 5. On both sides of the air cylinder 3, a pair of spring seats 6 are provided inside the apparatus main body 1, and an elastic member 7 such as a coil spring is moored between the spring seat 6 and the holder 4. The elastic member 7 applies an upward elastic force to the holder 4, and in particular,
When the pressure air for ascending operation is not supplied to the air cylinder 3 from a pressure air supply circuit (not shown), the elastic force prevents the holder 4 from dropping under its own weight and holds the holder 4 at the ascending limit position. .

The holder 4 holds a rod-shaped resonator 8 made of a material having good acoustic characteristics, such as titanium, inside the upper part of the work space 2 in a state where both ends are supported horizontally. Resonator 8
One end of the vibrator 9 such as an acoustic transducer or a magnetostrictive transducer
Are coaxially coupled to each other, the vibrator generates ultrasonic vibrations by electric energy received from the ultrasonic oscillator 10 through the electric wire 11, and the resonator 8 is driven by the frequency transmitted from the vibrator 9. It is formed in a shape that matches the determined resonance frequency. The resonator 8 has a minimum vibration amplitude point of the resonance frequency at both ends, has a maximum vibration amplitude point of the resonance frequency at least at the center, and has a joining action portion 8a protruding from the outer peripheral surface at the center. The joining action portion 8a has a flat surface having substantially the same shape as the base 15a of the first member 15. On this surface, a buffer member 12 is fixedly provided. The cushioning member 12 has a form in which one surface material such as Teflon, polyethylene, or polypropylene is coated in a flat layer over the entire surface.

In the resonator 8, an annular support portion 8b projecting from the outer peripheral surface of two minimum vibration amplitude points existing between the center maximum vibration amplitude point and the minimum vibration amplitude points at both ends is opposed to the holder 4. The resonator 8 is attached to the holder 4 in such a form as to be inserted and mounted on the leading end. Although the resonator 8 may be formed as a single body, a composite body in which two boosters having support portions 8b at both ends of a horn having a joint action portion 8a are coaxially connected via a headless screw. May be formed.
When the holder 4 is moved downward by the air cylinder 3 toward the receiving table 13, the buffer member 12 of the resonator 8 is moved.
The lower surface of the pedestal 1 is kept parallel to the flat upper surface of the pedestal 13.
Go down to 3 side. The descending distance may be a distance at which the cushioning member 12 comes into contact with the pedestal 13, but the joined portion 15 b of the first member 15 and the joined portion 16 a of the second member 16 come into contact with each other, and the first member 15 The joining member 8a and the pedestal 13 are slightly smaller than the thickness t in which the second member 16 is overlapped, and the first member 15 and the second member 16 are compressed via the cushioning member 12. It is best if the base member 15a is pressed and clamped by the above and the dimensions are such that the base 15a of the first member 15 is not damaged. The pedestal 13 has a lower surface portion of the apparatus main body 1 which divides the back of the working space 2 on a surface plate 14 which constitutes a base for assembling the ultrasonic device to a production line such as surface mounting of a semiconductor device. Will be installed.

The first member 15 is made of, for example, an IC chip or L
Like a SI package or the like, a base portion 15a made of a ceramic or the like that is brittle against impact has a bonded portion 15b made of metal such as a pump made of gold or solder. The second member 16 has, for example, a metal bonded portion 16a which is a bump made of gold or solder on a surface of a circuit board such as a printed board for surface mounting the first member 15. First member 15
When the part 15b of the first member 15 is made of gold, the part 16a of the second member 16 is also made of gold.
Is soldered, the joined parts 16a of the second member 16 are also made of solder.
It is best in terms of bonding strength that a is formed of the same material, but different materials may be used as long as they can be bonded to each other by ultrasonic vibration.

The operation of the first embodiment will be described. By switching the air supply path of the pressure air supply circuit (not shown), as shown in FIG. 1, the piston rod 3a of the air cylinder 3 is driven to contract, and the joining action part 8a is driven by the ultrasonic wave from the vibrator 9 to the resonator 8. After moving a predetermined distance in a direction perpendicular to the vibration transmission direction and away from the pedestal 13, the piston rod 3 a stops and the joining action portion 8 a stops at the ascending limit, so that the lower surface of the cushioning member 12 A predetermined space 17 for entering and exiting the first and second members 15 and 16 which are overlapped is formed between the upper surface of the receiving table 13 and the upper surface of the receiving table 13. In this state, the first and second members 15 and 16 are mounted on the receiving table 13. In this state, the joined parts 15b and 16a are overlapped with each other, the base part 15a is on the joining action part 8a side of the resonator 8, and the second member 16 is on the pedestal 13 side. In the process of switching the air supply path of the pressurized air supply circuit to cause the piston rod 3a to extend and drive against the elastic force of the elastic member 7 and stop at the lower limit position, the base 15a mounted on the receiving table 13 is moved. Pressed by the cushioning member 12, the parts to be joined 15b and 16a come into close contact with each other and the second member 16
Is in close contact with the pedestal 13, and the first member 15 and the second member 16 are connected to the joint 8a of the resonator 8 and the pedestal 13 as shown in FIG.
And pressurized.

As shown in FIG. 2, the first and second members 15, 1
Either after the pressure holding of 6, or before the pressure holding, high frequency energy is supplied from the ultrasonic oscillator 10 to the vibrator 9, the vibrator 9 generates ultrasonic vibration, and the resonator 8 Resonating with the ultrasonic vibration reached from the vibrator 9, the bonding portion 8 a vibrates with the maximum vibration amplitude in the direction of arrow X orthogonal to the direction of pressing of arrow Y by the air cylinder 3, and the cushioning member 12. The joined surface 15b of the first member 15 and the joined surface 16a of the second member 16 are non-melt-joined to each other via the joint.

According to the first embodiment, as shown in FIG. 2, in a state where the first member 15 and the second member 16 are pressed and clamped between the joining action portion 8a of the resonator 8 and the receiving base 13. ,
Joint action portion 8a between base 15a of first member 15 and resonator 8
The cushioning member 12 bears an impact on the base 15a, such as ceramic, which is fragile to the impact on the first member 15 from the joining action portion 8a, and damages the base 15a of the first member 15 because Can be prevented.

According to the first embodiment, the cushioning member 12
Is the joint action portion 8 between the base 15a of the first member 15 and the resonator 8.
a, the cushioning member 12 is
-Absorbs variations in thickness of the second members 15 and 16 within a tolerance range and deviations in parallelism between the joint action portion 8a and the pedestal 13 so as to absorb all the joined portions 15b of the first member 15 and the second portion. Since all the parts 16a to be joined of the member 16 are entirely in close contact with each other and are joined by ultrasonic vibration, the first and second members 15, 1
6 can be prevented from being defectively joined to each other.

According to the first embodiment, the cushioning member 12
Is provided on the joining action portion 8a, so that the joining workability is improved.

FIG. 3 is an enlarged view of the second embodiment of the present invention, which is characterized in that a buffer member 18 corresponding to the buffer member 12 is fixedly provided on a base 15a of the first member 15. is there. The buffer member 18 has a form in which the entire upper surface of the base 15a of the first member 15 is coated in a flat layer. Therefore, according to the second embodiment, the cushioning member 18 becomes new each time ultrasonic bonding is performed, so that there is no need to worry about the wear of the cushioning member 15.

FIG. 4 is an enlarged view of a third embodiment of the present invention, in which a cushioning member 19 corresponding to the cushioning member 12 includes a joining action portion 8 a of the resonator 8 and a base of the first member 15. 15a, the first and second members 15,
16 and the base 15 before the pressing and holding of the base 16
a is inserted and arranged in the gap between them. The lowering operation of the resonator 8 is characterized in that the cushioning member 19 is sandwiched between the joining portion 8a and the base 15a. Therefore, a new one can be obtained for each ultrasonic bonding, and the resonator 8 and the first member 15 may be in a simple form without any buffer member. In this case, if the buffer member is supported by a support mechanism (not shown), work safety can be ensured.

In each of the above embodiments, the surface of the bonding portion 8a is flat. However, a rectangular lattice (caramel lattice) having a large number of vertical and horizontal grooves formed on the surface or a large number of grooves obliquely crossing the vertical and horizontal directions. If a diagonal lattice (diamond lattice) or the like is formed, the joining action portion 8a becomes the first
Since the second members 15 and 16 are supported at multiple points between the second member 15 and the mounting table 13, the ultrasonic vibration is applied to the first member 15 from the bonding portion 8 a.
-Good transmission to the side of the second members 15 and 16, and the
The joint between 5b and 16a is improved.

In the first embodiment, the joining action portion 8a
If a rectangular lattice (caramel lattice) having a large number of grooves perpendicular to the vertical and horizontal directions or a diagonal lattice (diamond lattice) having a large number of grooves diagonally crossing the vertical and horizontal directions, etc., is formed on the surface of the surface, the coating is applied to the bonding action portion 8a Since a part of the cushioning member 12 thus formed enters the groove of the rectangular lattice or the diagonal lattice, the joining action portion 8
a and the buffer member 12 are firmly connected to each other.

In each of the above embodiments, at the time of ultrasonic vibration bonding with the first and second members 15 and 16, a heater such as an electric heater is provided on at least one of the resonator 8 and the mounting table 13, and this heater is provided. And the mounting table 13
When the overlapped portion of the first and second members 15 and 16 sandwiched between the first and second members 15 and 16 is heated, it is optimal that the buffer member 12 is made of a material having heat resistance to the heat of the joining operation.

In each of the above embodiments, the first and second members 15,
When the resonator 8 is lowered in a state where the resonator 16 and the mounting table 13 are superimposed, the resonator 8 is lowered in a state where the resonator 8 and the mounting table 13 are overlapped. However, an element including the holder 4, the air cylinder 3, the connecting member 5, the spring seat 6, and the elastic member 7 is assembled to a laterally movable member instead of the apparatus main body 1, and penetrates through the joint action portion 8a. The suction passage having a suction source such as a vacuum pump or a valve is connected to the suction passage, and the first member 15 is placed on the mounting table 13 by the resonator 8. The same applies to a mode in which the first and second members on which the resonator 8 and the mounting table 13 are overlapped are sandwiched while being overlapped on the second member 16.

The cushioning members 12, 1 in each of the above embodiments.
If the materials 8 and 19 are made of a material that does not slip easily with respect to the resonator 8 and the first member 15, the joining work is improved.

[0023]

According to the first aspect of the present invention, the metal joint provided on the base fragile to the impact of the first member and the metal joint provided on the second member are overlapped, First
When the base of the member is on the side of the joint acting portion of the resonator and the second member is on the pedestal side, when the first member and the second member are pressed and sandwiched between the resonator and the pedestal, the buffer member is Since it is sandwiched between the joining action part of the resonator and the base of the first member, the shock-absorbing member bears an impact on the base of the first member from the joining action part, and it is possible to prevent damage to the base that is fragile to the impact. Further, the cushioning member is compressed between the base of the first member and the joining action portion of the resonator, so that the cushioning member has a thickness variation within the tolerance range of the first and second members and the joining action portion. The irregularity of the parallelism between the first member and the pedestal is absorbed, and the part to be joined of the first member and the part to be joined of the second member are entirely in close contact with each other and joined by ultrasonic vibration. Bonding failure can be prevented. According to the second aspect of the present invention, since the cushioning member according to the first aspect is provided in the joining operation portion, it is not necessary to insert the impact member between the resonator and the first member for each ultrasonic joining. The workability of joining is improved. According to the third aspect of the present invention, since the impact member is provided on the first member, the cushioning member becomes a new one each time ultrasonic bonding is performed. It can be performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an ultrasonic vibration bonding apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is an enlarged view according to a second embodiment of the present invention.

FIG. 4 is an enlarged view according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 8 resonator 8a joining action part 12 buffer member 15 first member 15a base 15b joined part 16 second member 16a joined part

Claims (3)

(57) [Claims] 1. A metal bonded part provided on a base fragile to the impact of a first member and a metal bonded part of a second member are overlapped, and the base of the first member is formed of a resonator. The first member and the second member are pressurized and sandwiched between the resonator and the pedestal, and the ultrasonic vibration transmitted to the resonator from the vibrator is provided on the joining action portion side, with the second member serving as the pedestal side. An ultrasonic vibration bonding apparatus for bonding a portion to be joined of a first member and a portion to be joined of a second member, the device having a buffer member sandwiched between a joining action portion of the resonator and a base of the first member. An ultrasonic vibration bonding apparatus characterized by the above-mentioned. 2. The ultrasonic vibration bonding apparatus according to claim 1, wherein the buffering member is provided on the bonding section. 3. The ultrasonic vibration bonding apparatus according to claim 1, wherein the impact member is provided on the first member.