JP2007005546A - Ultrasonic flip-chip connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic flip-chip connector capable of surely connecting a semiconductor chip and a circuit board in a flip chip manner without damaging the semiconductor chip. <P>SOLUTION: An ultrasonic horn 22 is resonated in the ultrasonic vibrating direction A by the ultrasonic vibrations of an ultrasonic vibrator 25. A chip holder 27 is fitted to the ultrasonic horn 22. The chip holder 27 holds the semiconductor chip 23 in parallel with the ultrasonic vibrating direction A. A board holder 28 holds the circuit board 24 in parallel with the semiconductor chip 23. A pushing means 29 pushes the semiconductor chip 23 against the circuit board 24. The section of the web place of the ultrasonic horn 22 is supported by a supporting means 26 so as to be able to be vibrated in the ultrasonic vibrating direction A by such a connector 21. The ultrasonic vibrator 25 is arranged at the knot place of the ultrasonic horn 22, and both ends 25a and 25b in the ultrasonic vibrating direction A are mounted on the ultrasonic horn 22 under the state in which both ends are brought into contact with the ultrasonic horn 22. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrasonic flip chip bonding apparatus that performs flip chip bonding of a semiconductor chip and a circuit board using ultrasonic vibration.

  As a bonding method for bonding the semiconductor chip and the circuit board, there are a wire bonding method and a flip chip bonding method. The wire bonding method is a method in which an electrode of a semiconductor chip and an electrode of a circuit board are bonded through a wire. The flip chip bonding method is a method in which an electrode of a semiconductor chip and an electrode of a circuit board are bonded through bumps.

  The flip chip bonding method can reduce the mounting area and the wiring length compared to the wire bonding method. Further, in the flip chip bonding method, the electrode group of the semiconductor chip and the electrode group of the circuit board are bonded together, and this flip chip bonding method is superior in productivity compared to the wire bonding method. Such a flip-chip bonding method is suitable for high-density mounting and high-speed semiconductor chip mounting.

  The flip chip bonding method includes a thermocompression bonding method and an ultrasonic bonding method. In particular, in the ultrasonic bonding method, bonding at a temperature lower than 150 ° C. is possible, and the bonding time required for bonding is as short as about 1 second. Such an ultrasonic bonding method has recently attracted attention from the viewpoint of bonding productivity. The ultrasonic bonding method in the flip chip bonding method is also called an ultrasonic flip chip bonding method.

  In recent years, various ultrasonic flip chip bonding apparatuses for realizing an ultrasonic flip chip bonding method have been developed.

  The first prior art is disclosed in Patent Document 1. In this conventional ultrasonic bonding apparatus, the ultrasonic horn has a length corresponding to one wavelength of ultrasonic waves. At the center of the ultrasonic horn, an engagement tip that engages with the member to be joined is provided. A booster is connected to both ends of the ultrasonic horn coaxially with the ultrasonic horn. Each booster has a half-wavelength of ultrasonic waves, and both ends thereof are antinodes of resonance and the center is a node of resonance. The central part of each booster is directly and mechanically clamped by a pair of support members. One booster is connected to an ultrasonic transducer coaxially with the booster. The pressurizing means is configured such that the engaging tip pressurizes the member to be joined by relatively moving the cradle on which the member to be joined is placed and each support member.

  FIG. 8 is a front view showing a simplified configuration of the ultrasonic bonding apparatus 1 of the second prior art. The second prior art is disclosed in Patent Document 2. In this conventional ultrasonic bonding apparatus 1, the ultrasonic horn 2 is preset to a length corresponding to one wavelength of the ultrasonic wave, and both ends and the center thereof are antinodes of resonance. In the central part of the ultrasonic horn 2, a bonding action part 3 is provided. An ultrasonic transducer 4 is connected to one end of the ultrasonic horn 2 on the same axis. The ultrasonic transducer 4 causes the ultrasonic horn 2 to vibrate laterally. The two portions that become the nodes of the ultrasonic horn are fixed by the support members 5a and 5b, respectively. The pressurizing means 6 is configured to bring the printed circuit board 8 placed on the cradle 7 into contact with the bare chip 9 held by the bonding operation section 3 and pressurize both.

Japanese Patent No. 2583398 JP 2004-330228 A

  In the first prior art, since the ultrasonic transducer is provided outside the ultrasonic horn, the ultrasonic transducer is supported from one side in the ultrasonic vibration direction. Therefore, since the ultrasonic vibrator is displaced during ultrasonic vibration, there is a problem that the stability of resonance is low and it is difficult to obtain stable joining of the members to be joined.

  In the first prior art, each booster is fixed to each support member at a central portion serving as a resonance node, so that vibration in a direction perpendicular to the ultrasonic vibration direction is generated. Therefore, there is a problem that the member to be joined is easily damaged.

  More specifically, the part that becomes the resonance node of each booster does not vibrate, but the pressure changes most. Since each booster is made of a highly rigid material, it has incompressibility and its volume changes with respect to changes in pressure are negligible. In each of these boosters, the pressure change appears as a change in the cross-sectional area perpendicular to the ultrasonic vibration direction at the resonance node. Therefore, when each booster is fixed to each support member at a resonance node, vibration in a direction perpendicular to the ultrasonic vibration direction is generated. As a result, the member to be joined is easily damaged.

  In the second prior art, since the ultrasonic transducer 4 is provided outside the ultrasonic horn 2, the ultrasonic transducer 4 is supported from one side in the ultrasonic vibration direction. Therefore, there is a problem similar to that of the first prior art, that is, it is difficult to obtain a stable joint between the printed circuit board 8 and the bare chip 9.

  In the second prior art, the ultrasonic horn 2 is fixed by the support members 5a and 5b at the node of resonance. Therefore, there is a problem similar to the first prior art, that is, there is a problem that the bare chip 9 is easily damaged.

  More specifically, although the portion that becomes the resonance node of the ultrasonic horn 2 does not vibrate, the pressure changes most. Since the ultrasonic horn 2 is made of a highly rigid material, the ultrasonic horn 2 has incompressibility, and its volume changes with respect to changes in pressure are negligible. In such an ultrasonic horn 2, the pressure change appears as a change in the area of the cross section perpendicular to the ultrasonic vibration direction at the node of resonance. Therefore, when the ultrasonic horn 2 is fixed to the support members 5a and 5b at the resonance node, vibration in a direction perpendicular to the ultrasonic vibration direction is generated. As a result, the bare chip 9 is easily damaged.

  Accordingly, an object of the present invention is to provide an ultrasonic flip chip bonding apparatus that can reliably perform flip chip bonding between a semiconductor chip and a circuit board without damaging the semiconductor chip, thereby improving yield. That is.

  In the first and second prior arts, since the ultrasonic transducer 4 is provided outside the ultrasonic horn 2, the ultrasonic transducer 4 is supported from one side in the ultrasonic vibration direction. Accordingly, since the ultrasonic vibration of the ultrasonic transducer 4 is effective only on one side, there is a problem that the transmission efficiency of the ultrasonic vibration is poor.

  Accordingly, another object of the present invention is to provide an ultrasonic flip chip bonding apparatus capable of improving the transmission efficiency of ultrasonic vibration.

The present invention is an ultrasonic flip chip bonding apparatus for flip chip bonding a semiconductor chip and a circuit board using ultrasonic vibration,
An ultrasonic vibrator that vibrates ultrasonically;
An ultrasonic horn that resonates in the direction of ultrasonic vibration by ultrasonic vibration by an ultrasonic vibrator;
Support means for supporting the ultrasonic horn;
A chip holder that is provided in the ultrasonic horn and holds the semiconductor chip in parallel with the ultrasonic vibration direction;
A substrate holder for holding the circuit board in parallel with the semiconductor chip held by the chip holder;
Pressing means for pressing the semiconductor chip held by the chip holder against the circuit board held by the substrate holder,
The support means supports the antinode portion of the ultrasonic horn so that the antinode portion of the ultrasonic horn can vibrate in the ultrasonic vibration direction.
The ultrasonic transducer is arranged at a resonance node position in the ultrasonic horn, and is provided in the ultrasonic horn with both ends in the ultrasonic vibration direction being in contact with the ultrasonic horn. Device.

In the present invention, when there are a plurality of resonance node positions in the ultrasonic horn,
The ultrasonic transducer is arranged at a node position farthest from the chip holder among the plurality of node positions.

  Further, the invention is characterized in that the supporting means supports both ends of the ultrasonic horn in the ultrasonic vibration direction.

  The present invention is characterized in that the inertial mass of the ultrasonic horn is selected to be 1.0% or less of the inertial mass of the entire apparatus.

In the present invention, the supporting means is
A support member connected to the antinode portion of the ultrasonic horn and extending in the pressing direction of the semiconductor chip, and having flexibility in the ultrasonic vibration direction;
A holder connected to the end of the support member opposite to the side connected to the ultrasonic horn,
The substrate holder holds the circuit board at a position retracted in a direction opposite to the pressing direction of the semiconductor chip from an end of the support member opposite to the side connected to the ultrasonic horn. To do.

Further, the present invention is an ultrasonic flip chip bonding apparatus for flip chip bonding a semiconductor chip and a circuit board using ultrasonic vibration,
An ultrasonic vibrator that vibrates ultrasonically;
An ultrasonic horn that resonates in the direction of ultrasonic vibration by ultrasonic vibration by an ultrasonic vibrator;
A chip holder that is provided in the ultrasonic horn and holds the semiconductor chip in parallel with the ultrasonic vibration direction;
A substrate holder for holding the circuit board in parallel with the semiconductor chip held by the chip holder;
Pressing means for pressing the semiconductor chip held by the chip holder against the circuit board held by the substrate holder,
The ultrasonic transducer is arranged at a resonance node position in the ultrasonic horn, and is provided in the ultrasonic horn with both ends in the ultrasonic vibration direction being in contact with the ultrasonic horn. Device.

  According to the present invention, the ultrasonic transducer vibrates ultrasonically. The ultrasonic horn resonates in the ultrasonic vibration direction by the ultrasonic vibration of the ultrasonic vibrator. A chip holder is provided in the ultrasonic horn. This chip holder resonates with the ultrasonic horn.

  The chip holder holds the semiconductor chip in parallel with the ultrasonic vibration direction. The substrate holder holds the circuit board in parallel with the semiconductor chip held by the chip holder. The pressing means presses the semiconductor chip held by the chip holder against the circuit board held by the substrate holder.

  Therefore, the semiconductor chip can be vibrated in a direction parallel to the semiconductor chip in a pressed state in which the semiconductor chip is pressed against the circuit board. Thereby, the semiconductor chip and the circuit board can be flip-chip bonded.

  The antinode portion of the ultrasonic horn is less vibrated in the direction perpendicular to the ultrasonic vibration direction than the remaining portion. Considering this, the portion of the abdominal position is supported by the support means. As a result, the problem that the semiconductor chip vibrates in a direction perpendicular to the semiconductor chip in the pressed state can be suppressed as much as possible. Therefore, damage to the semiconductor chip can be prevented.

  The antinode portion of the ultrasonic horn vibrates in the ultrasonic vibration direction. Considering this, the antinode portion is supported by the support means so that the antinode portion can vibrate in the ultrasonic vibration direction. As a result, the influence of the support means for supporting the ultrasonic horn on the resonance of the ultrasonic horn can be suppressed.

  The ultrasonic transducer is disposed at a resonance node position in the ultrasonic horn. The minute vibration at the node position of the ultrasonic horn becomes large vibration at the antinode position of the ultrasonic horn. Therefore, the ultrasonic vibration of the ultrasonic vibrator can be used effectively, and the transmission efficiency of the ultrasonic vibration can be improved.

  Moreover, the ultrasonic vibrator is provided in the ultrasonic horn in a state where both ends in the ultrasonic vibration direction are in contact with the ultrasonic horn. As described above, since the ultrasonic vibrator is supported from both sides in the ultrasonic vibration direction, the problem that the ultrasonic vibrator is displaced during ultrasonic vibration can be prevented. Thereby, the stability of resonance can be improved, and the semiconductor chip and the circuit board can be reliably flip-chip bonded. In addition, since the above-mentioned problem is prevented, the ultrasonic vibration of the ultrasonic vibrator can be used more effectively, and the transmission efficiency of the ultrasonic vibration can be further improved.

  In the present invention, the semiconductor chip and the circuit board can be reliably flip-chip bonded without damaging the semiconductor chip. Therefore, the yield can be improved and the production cost can be reduced.

  Further, according to the present invention, when there are a plurality of resonance node positions in the ultrasonic horn, the ultrasonic transducer is arranged at a node position farthest from the chip holder among the plurality of node positions. Therefore, it is possible to suppress the influence of the ultrasonic vibrator from the chip holder. For example, when the chip holder is heated, the problem that the ultrasonic vibrator is also heated is prevented. Since the above problems are prevented, a piezoelectric element having low heat resistance can be used as an ultrasonic vibrator.

  Further, according to the present invention, both ends of the ultrasonic horn in the ultrasonic vibration direction are portions at the antinode position of resonance, and the support means supports the both ends of the ultrasonic horn in the ultrasonic vibration direction. Therefore, the ultrasonic horn and the support means can be easily connected by fastening using a bolt member.

  According to the present invention, the inertial mass of the ultrasonic horn is selected to be 1.0% or less of the inertial mass of the entire apparatus. When the ultrasonic horn is resonating, the center of gravity remains unchanged, but the antinode portion vibrates in the ultrasonic vibration direction. Therefore, vibration is transmitted to the support means. Due to this vibration, the remaining part of the entire apparatus except the ultrasonic horn may vibrate. When the inertial mass of the ultrasonic horn exceeds 1.0% of the inertial mass of the entire apparatus, the remaining portion vibrates with the resonance of the ultrasonic horn. When the inertial mass of the ultrasonic horn is set to 1.0% or less of the inertial mass of the entire apparatus, a problem that the remaining portion vibrates with the resonance of the ultrasonic horn is prevented.

  According to the invention, the support member is connected to the antinode portion of the ultrasonic horn and extends in the pressing direction of the semiconductor chip. A holder is connected to the end of the support member opposite to the side connected to the ultrasonic horn. The substrate holder holds the circuit board at a position retracted in the direction opposite to the pressing direction of the semiconductor chip from the end of the support member opposite to the side connected to the ultrasonic horn. Accordingly, the substrate holding body can be enlarged and the inertial mass of the substrate holding body can be increased without increasing the size of the entire apparatus.

  By increasing the inertial mass of the substrate holder in this way, it is possible to suppress the vibration of the substrate holder that occurs during ultrasonic flip chip bonding. As a result, a decrease in relative vibration between the semiconductor chip and the circuit board can be suppressed, and the semiconductor chip and the circuit board can be reliably flip-chip bonded. Therefore, a module having high reliability can be obtained, and the yield can be improved.

  According to the present invention, the ultrasonic transducer vibrates ultrasonically. The ultrasonic horn resonates in the ultrasonic vibration direction by the ultrasonic vibration of the ultrasonic vibrator. A chip holder is provided in the ultrasonic horn. This chip holder resonates with the ultrasonic horn.

  The chip holder holds the semiconductor chip in parallel with the ultrasonic vibration direction. The substrate holder holds the circuit board in parallel with the semiconductor chip held by the chip holder. The pressing means presses the semiconductor chip held by the chip holder against the circuit board held by the substrate holder.

  Therefore, the semiconductor chip can be vibrated in a direction parallel to the semiconductor chip in a pressed state in which the semiconductor chip is pressed against the circuit board. Thereby, the semiconductor chip and the circuit board can be flip-chip bonded.

  The ultrasonic transducer is disposed at a resonance node position in the ultrasonic horn. The minute vibration at the node position of the ultrasonic horn becomes large vibration at the antinode position of the ultrasonic horn. Therefore, the ultrasonic vibration of the ultrasonic vibrator can be used effectively, and the transmission efficiency of the ultrasonic vibration can be improved.

  Moreover, the ultrasonic vibrator is provided in the ultrasonic horn in a state where both ends in the ultrasonic vibration direction are in contact with the ultrasonic horn. As described above, since the ultrasonic vibrator is supported from both sides in the ultrasonic vibration direction, the problem that the ultrasonic vibrator is displaced during ultrasonic vibration can be prevented. Accordingly, the ultrasonic vibration of the ultrasonic vibrator can be used more effectively, and the transmission efficiency of the ultrasonic vibration can be further improved. In addition, since the above-mentioned problems are prevented, the stability of resonance can be improved, and the semiconductor chip and the circuit board can be reliably flip-chip bonded.

  FIG. 1 is a diagram for explaining the configuration of an ultrasonic flip-chip bonding apparatus 21 according to an embodiment of the present invention. FIG. 1 (1) is a front view of the vicinity of an ultrasonic horn 22, and FIG. 2) is a diagram showing a waveform of a standing wave generated in the ultrasonic horn 22. FIG. An ultrasonic flip chip bonding apparatus (hereinafter referred to as “bonding apparatus”) 21 according to the present embodiment is used for flip chip bonding of a semiconductor chip 23 and a circuit board 24.

  The semiconductor chip 23 is configured, for example, by forming a fine electronic circuit pattern on a silicon substrate. A plurality of electrodes are formed on one surface of the semiconductor chip 23. The circuit board 24 is configured, for example, by forming a wiring pattern on an organic substrate. A plurality of electrodes are formed on one surface of the circuit board 24. Each electrode of the semiconductor chip 23 is provided with a bump. The bump is, for example, an Au ball bump. The diameter of the Au ball bump is, for example, 60 μm. In flip-chip bonding, each electrode of the semiconductor chip 23 and each electrode of the circuit board 24 are bonded via bumps.

  The bonding apparatus 21 according to the present embodiment uses ultrasonic vibration when the semiconductor chip 23 and the circuit board 24 are flip-chip bonded. The bonding apparatus 21 includes an ultrasonic vibrator 25 that vibrates ultrasonically, an ultrasonic horn 22 that resonates in the ultrasonic vibration direction A by ultrasonic vibration generated by the ultrasonic vibrator 25, and a support unit that supports the ultrasonic horn 22. 26, a chip holder 27 that is provided in the ultrasonic horn 22 and holds the semiconductor chip 23, a substrate holder 28 that holds the circuit board 24, and a semiconductor chip 23 that is held by the chip holder 27 are held by the substrate. And pressing means 29 for pressing the circuit board 24 held by the body 28.

  In such a bonding apparatus 21, the semiconductor chip 23 and the bumps are parallel to the semiconductor chip 23 in a pressed state in which the electrodes of the semiconductor chip 23 are pressed against the electrodes of the circuit board 24 through the bumps. Can be vibrated. As a result, each bump and each electrode of the circuit board 24 rub against each other, and the contaminated layer covering the surface of each bump and the contaminated layer covering the surface of each electrode of the circuit board 24 are removed. Each electrode of the substrate 24 is bonded. In this way, the semiconductor chip 23 and the circuit board 24 are bonded.

  The ultrasonic transducer 25 vibrates ultrasonically at a predetermined frequency. The predetermined frequency is selected to be 50 kHz, for example. The ultrasonic transducer 25 is realized by a piezoelectric element. The piezoelectric element is also called a piezo element. Piezoelectric elements are energy converters that convert electrical energy into mechanical energy. The ultrasonic vibrator 25 is realized by, for example, a piezoelectric element made of lead zirconate titanate.

  The ultrasonic horn 22 has a length D1 corresponding to one wavelength of the ultrasonic wave with respect to the ultrasonic vibration direction A of the ultrasonic vibrator 25. Therefore, the ultrasonic horn 22 can resonate in the ultrasonic vibration direction A by the ultrasonic vibration by the ultrasonic vibrator 25. The ultrasonic wavelength serving as a reference for the length of the ultrasonic horn 22 is the wavelength of the ultrasonic wave transmitted through the ultrasonic horn 22 by the ultrasonic vibration of the ultrasonic transducer 25. The ultrasonic horn 22 has a substantially cylindrical shape, and its axial direction coincides with the ultrasonic vibration direction A. The ultrasonic horn 22 is made of, for example, iron. The inertial mass of the ultrasonic horn 22 is selected to be 1.0% or less of the inertial mass of the entire joining device 21 within a range in which the required rigidity of the ultrasonic hole 22 can be obtained.

  The support means 26 supports the both end portions 22a and 22b of the ultrasonic horn 22 so that both end portions 22a and 22b in the ultrasonic vibration direction A of the ultrasonic horn 22 can vibrate in the ultrasonic vibration direction A. . Accordingly, the ultrasonic horn 22 can resonate in the ultrasonic vibration direction A with both ends of the ultrasonic vibration direction A being free ends by ultrasonic vibration by the ultrasonic vibrator 25.

  The chip holder 27 is provided at the central portion 22 c between both end portions 22 a and 22 b in the ultrasonic vibration direction A of the ultrasonic horn 22. The chip holding body 27 is formed with a chip holding surface 27a parallel to the ultrasonic vibration direction A. The area of the chip holding surface 27 a is larger than the chip area of the semiconductor chip 23. The other surface of the semiconductor chip 23 abuts on the chip holding surface 27a. Therefore, the chip holder 27 can hold the semiconductor chip 23 in parallel with the ultrasonic vibration direction A. In the present embodiment, the chip holding surface 27a forms a horizontal plane, the chip holding body 27 holds the semiconductor chip 23 horizontally, and one surface of the semiconductor chip 23 faces downward. The chip holder 27 is made of, for example, iron. The chip holder 27 is formed integrally with the ultrasonic horn 22.

  The substrate holder 28 is formed with a substrate holding surface 28a parallel to the ultrasonic vibration direction A. The area of the board holding surface 28 a is larger than the board area of the circuit board 24. The other surface of the circuit board 24 contacts the board holding surface 28a. Therefore, the substrate holder 28 can hold the circuit board 24 in parallel with the semiconductor chip 23 held by the chip holder 27. In the present embodiment, the substrate holding surface 28a forms a horizontal plane, and the substrate holder 28 holds the circuit board 24 horizontally, and one surface of the circuit board 24 faces upward. The substrate holder 28 is made of, for example, stainless steel (SUS). The substrate holder 28 is also called a bonding stage.

  The pressing means 29 applies a pressing force in the pressing direction B1 along the reference axis L1 to the chip holder 27 via the support means 26 and the ultrasonic horn 22. The reference axis L1 is perpendicular to the chip holding surface 27a and intersects the axis of the ultrasonic horn 22 at the center in the ultrasonic vibration direction A of the ultrasonic horn 22. By such pressing means 29, the semiconductor chip 23 held by the chip holder 27 can be pressed against the circuit board 24 held by the substrate holder 28.

  FIG. 2 is a perspective view showing the support member 31a. Referring also to FIG. 1, the support means 26 includes a pair of support members 31 a and 31 b, a pair of connecting members 32 a and 32 b, and a holder 33. In the present embodiment, the support means 26 is configured to be plane-symmetric with respect to a predetermined virtual plane. The predetermined virtual plane includes the reference axis L1 and is perpendicular to the ultrasonic vibration direction A.

  The support members 31a and 31b are respectively connected to both end portions 22a and 22b in the ultrasonic vibration direction A of the ultrasonic horn 22 by bolt members and extend in the pressing direction B1. The connecting members 32a and 32b are connected to the ends of the support members 31a and 31b opposite to the side connected to the ultrasonic horn 22 by bolt members, respectively, and extend in directions away from each other.

  The holder 33 is generally C-shaped and is provided so as to surround the ultrasonic horn 22. The holder 33 includes a top plate 34 that extends in the ultrasonic vibration direction A, and a pair of side plates 35a and 35b that are bent and connected to both end portions of the top plate 34 in the ultrasonic vibration direction A and extend in the pressing direction B1. At the end of each side plate 35a, 35b opposite to the side connected to the top plate 34, the end of each connecting member 32a, 32b opposite to the side connected to each support member 31a, 31b is a bolt. Each is connected by a member.

  Each support member 31a, 31b is a flat plate-like body made of iron. As an example, the thickness T1 of each support member 31a, 31b is 5 to 15 mm. Each of such support members 31a and 31b has flexibility in the thickness direction C and rigidity in a direction perpendicular to the thickness direction C.

  The support members 31a and 31b are respectively connected to both end portions 22a and 22b of the ultrasonic horn 22 in the ultrasonic vibration direction A in a state where the thickness direction C thereof coincides with the ultrasonic vibration direction A. Accordingly, the support members 31a and 31b support the both end portions 22a and 22b of the ultrasonic horn 22 so that the both end portions 22a and 22b of the ultrasonic horn 22 can vibrate in the ultrasonic vibration direction A. it can.

  Since each support member 31a and 31b is the same, one support member 31a is demonstrated in detail, and detailed description is abbreviate | omitted about the other support member 31b. A first through hole 37 penetrating in the thickness direction C is formed at one end 36 in the longitudinal direction of the support member 31a. A threaded portion of a bolt member for connecting the ultrasonic horn 22 and the support member 31 a is gently inserted into the first through hole 37. A second through hole 39 penetrating in the thickness direction C is formed in the other longitudinal end portion 38 of the support member 31a. A threaded portion of a bolt member for connecting the support member 31a and the connecting member 32a is gently inserted into the second through hole 39.

  FIG. 3 is an enlarged cross-sectional view showing one end 22 a of the ultrasonic horn 22 in the ultrasonic vibration direction A. The ultrasonic horn 22 has a horn body 42 in which an insertion hole 41 is formed, and a plug 43 that is inserted into the insertion hole 41 of the horn body 42.

  An opening 45 is formed in one end face 44 of the horn body 42 in the ultrasonic vibration direction A. An insertion hole 41 extending in the ultrasonic vibration direction A communicates with the opening 45. A bottom surface 46 is formed at a position retracted from the opening 45 toward the other end surface of the horn body 42 in the ultrasonic vibration direction A by a predetermined retraction amount D2. The bottom surface 46 is a bottom surface of the recess 47 in which the opening 45 and the insertion hole 41 are formed. The bottom surface 46 forms a plane perpendicular to the ultrasonic vibration direction A.

  The ultrasonic transducer 25 is inserted into the insertion hole 41 through the opening 45, and the plug 43 is further inserted. The plug 43 can apply a pre-pressure to the ultrasonic transducer 25. In a state where the plug 43 is inserted into the insertion hole 41, the tip surface 48 of the plug 43 forms a single plane perpendicular to the ultrasonic vibration direction A.

  One end portion 25 a of the ultrasonic vibrator 25 in the ultrasonic vibration direction A is in contact with the tip surface 48 of the plug 43. The other end portion 25 b of the ultrasonic transducer 25 in the ultrasonic vibration direction A is in contact with the bottom surface 46 of the recess 47. Therefore, the ultrasonic transducer 25 is built in the ultrasonic horn 22 with both end portions 25 a and 25 b in the ultrasonic vibration direction A in contact with the ultrasonic horn 22.

  The predetermined retraction amount D2 is selected to be a length obtained by adding a length D3 that is ½ of the dimension in the ultrasonic vibration direction A of the ultrasonic transducer 25 to the length D3 of a quarter wavelength of the ultrasonic wave. . Therefore, the center of the ultrasonic vibration direction A of the ultrasonic transducer 25 can be disposed at a position that is closer to the other end by a quarter wavelength from one end of the ultrasonic horn 22 in the ultrasonic vibration direction A.

  The bottom surface 46 of the recess 47 and the front end surface 48 of the plug 43 are arranged at the center on the cross section perpendicular to the ultrasonic vibration direction A of the ultrasonic horn 22. Therefore, the ultrasonic horn 22 can be disposed at the center on the cross section. Thereby, the whole ultrasonic horn 22 can be resonated stably.

  A lead-out hole 49 communicating with the insertion hole 41 is formed around the insertion hole 41 of the horn body 42. The extraction hole 49 is disposed at the same position as the ultrasonic transducer 25 with respect to the ultrasonic vibration direction A. A resin layer having electrical insulation is formed on the inner peripheral surface facing the extraction hole 49 of the horn body 42.

  A cable 50 is electrically connected to the ultrasonic transducer 25. The cable 50 is drawn out of the horn main body 42 through the lead-out hole 49. The cable 50 drawn out of the horn main body 42 is led to the high frequency generator 51 in a slightly slack state. As a result, the vibration of the ultrasonic horn 22 in the direction perpendicular to the ultrasonic vibration direction A can be allowed.

  The cable 50 is electrically connected to the high frequency generator 51. The high frequency generator 51 provides a high frequency electrical signal to the ultrasonic transducer 25 via the cable 50. The ultrasonic transducer 25 vibrates mechanically, that is, ultrasonically vibrates in response to a high-frequency electric signal supplied from the high-frequency generator 51.

  FIG. 4 is a cross-sectional view of the chip holder 27. Referring also to FIG. 1, the chip holder 27 has a short quadrangular prism shape and protrudes outward from the outer peripheral surface of the ultrasonic horn 22. The tip surface of the chip holder 27 is the chip holding surface 27a.

  An opening 61 is formed in the chip holding surface 27a. The opening 61 is disposed at the center of the chip holding surface 27a. A first suction hole 62 extending along the reference axis L1 communicates with the opening 61. A second suction hole 63 extending in the ultrasonic vibration direction A communicates with the first suction hole 62. The second suction hole 63 communicates with a third suction hole 64 extending in a direction parallel to the chip holding surface 27a and perpendicular to the ultrasonic vibration direction A. A vacuum source 66 is connected to the third suction hole 64 via a conduit 65. Therefore, the semiconductor chip 23 in contact with the chip holding surface 27a can be vacuum-sucked.

  FIG. 5 is a front view showing the overall configuration of the bonding apparatus 21 in a simplified manner. The joining device 21 further includes a table 71. The table 71 is a movable table. The substrate holder 28 is placed on the table 71. The table 71 moves the substrate holder 28 in the X direction and the Y direction. The X direction and the Y direction are directions parallel to the substrate holding surface 28a and are orthogonal biaxial directions. By such a table 71, the semiconductor chip 23 and the circuit board 24 can be aligned.

  The pressing means 29 includes a base 72, a movable body 73 provided on the base 72 so as to be movable along the reference axis L1, and a movable body 73 displaced with respect to the base 72 along the reference axis L1. Displacement driving means 74.

  The base 72 includes a fixed substrate 75 and a pair of guide members 76a and 76b that are connected to the fixed substrate 75 and extend in the pressing direction B1 along the reference axis L1. The movable body 73 is formed with insertion holes 77a and 77b through which the guide members 76a and 76b are inserted. The movable body 73 is guided by the guide members 76a and 76b. The top plate 34 of the holder 33 is connected to the movable body 73.

  The displacement drive means 74 has a motor 78 fixed to the fixed substrate 75, a male screw portion 79 connected to the output shaft of the motor 78, and a female screw portion 80 through which the male screw portion 79 is inserted and screwed. . The external thread 79 is coaxial with the reference axis L1. The female thread portion 80 is formed integrally with the movable body 73. With such a displacement driving means 74, the chip holder 27 can be moved forward and backward along the reference axis L1 with respect to the substrate holder 28. Further, the semiconductor chip 23 can be pressed against the circuit board 24 by the displacement driving means 74.

  The substrate holder 28 is retracted in the direction B2 opposite to the pressing direction B1 from the ends 68, 69 opposite to the side connected to the ultrasonic horn 22 of the support members 31a, 31b. The circuit board 24 is held. As a result, the distance between the chip holding surface 27a of the chip holding body 27 and the substrate holding surface 28a of the substrate holding body 28 can be reduced, and the required amount of movement of the chip holding body 27 can be reduced.

  FIG. 6 is a block diagram showing an electrical configuration of the joining device 21. The joining device 21 further includes the vacuum source 66, a camera 81, a camera moving device 82, a pressure sensor 83, the high frequency generator 51, and a control means 84. The camera 81 images the semiconductor chip 23 and the circuit board 24. The camera moving device 82 moves the camera 81 between the imaging position and the retracted position. The pressure sensor 83 detects the pressing force of the semiconductor chip 23 against the circuit board 24.

  The control means 84 is configured by a central processing unit (abbreviated as CPU). The control means 84 is given an imaging result from the camera 81 and a detection result from the pressure sensor 83. The control means 84 controls the vacuum source 66, the table 71, the motor 78, the camera moving device 82, and the high frequency generator 51. The control means 84 has a timer 85.

  FIG. 7 is a flowchart for explaining the joining operation of the joining device 21. The bonding operation is started in a state where the semiconductor chip 23 is held by the chip holder 27 and the circuit board 24 is held by the substrate holder 28. In this state, one surface of the semiconductor chip 23 faces downward, one surface of the circuit board 24 faces upward, and one surface of the semiconductor chip 23 and one surface of the circuit board 24 face each other. When holding the semiconductor chip 23, suction is performed by the vacuum source 66 with the other surface of the semiconductor chip 23 being in contact with the chip holding surface 27 a of the chip holder 27.

  When the bonding operation is started, the semiconductor chip 23 and the circuit board 24 are aligned in step a1. In this step a1, first, the camera 81 is moved from the retracted position to the imaging position by the camera moving device 82, thereby causing the camera 81 to enter the space between the semiconductor chip 23 and the circuit board 24 without contact. Next, the semiconductor chip 23 and the circuit board 24 are imaged by the camera 81. When an imaging result is given from the camera 81, a relative positional deviation between the semiconductor chip 23 and the circuit board 24 is detected based on the imaging result. Based on the detection result, the table 71 is controlled so as to correct the positional deviation of the circuit board 24 with the semiconductor chip 23 as a reference. When the alignment is completed, the camera moving device 82 moves the camera 81 from the imaging position to the retracted position, and the process proceeds to step a2.

  In step a2, advancement of the chip holder 27 by the motor 78 is started, and the process proceeds to step a3. In step a3, based on the detection result given from the pressure sensor 83, it is determined whether or not the pressing force of the semiconductor chip 23 against the circuit board 24 exceeds a predetermined pressing value. The operation of step a3 is repeatedly executed until the predetermined pressing value is exceeded, and if it is determined that the predetermined pressing value has been exceeded, the process proceeds to step a4. In step a4, the advancement of the chip holder 27 by the motor 78 is terminated, and the process proceeds to step a5.

  In step a5, the ultrasonic vibration of the ultrasonic transducer 25 by the high frequency generator 51 is started, and the process proceeds to step a6. In step a6, it is timed by the timer 85, and it is determined whether or not a predetermined joining time has elapsed since the start of ultrasonic vibration by the ultrasonic transducer 25. The operation of step a6 is repeatedly executed until the predetermined joining time elapses. When it is determined that the predetermined joining time has elapsed, the process proceeds to step a7. In step a7, the ultrasonic vibration of the ultrasonic transducer 25 by the high frequency generator 51 is terminated, and the process proceeds to step a8. In Step a8, the tip 78 is moved backward by the motor 78, and the joining operation is completed.

  In such a joining operation, if it is determined in step a3 that the predetermined pressing value has been exceeded, the advancement of the tip holder 27 by the motor 78 is terminated in step a4. Further, the advancement of the tip holding body 27 may be continued until the other predetermined pressing value is high.

  In the present embodiment, a standing wave as shown in FIG. FIG. 1 (2) shows the displacement of each point in the ultrasonic horn 22. In FIG. 1 (2), the horizontal axis indicates the position of each point at rest, and the vertical axis indicates the displacement of each point from the position at rest. On the vertical axis, the displacement from the stationary position to the ultrasonic vibration direction A1 is positive, and the displacement from the stationary position to the ultrasonic vibration direction other A2 is negative. In FIG. 1 (2), only the waveforms of standing waves at the first and second times t1 and t2 at which the displacement of each point from the stationary position is maximum are shown.

  The waveform of the standing wave at the first time t1 is a sine curve as shown by a solid line 91, and the waveform of the standing wave at the second time t2 is a sine curve as shown by a virtual line 92. At the first time t1, the displacement of the ultrasonic horn 22 in the ultrasonic vibration direction A1 is the maximum at both ends in the ultrasonic vibration direction A, and the displacement in the ultrasonic vibration direction other A2 is the center between the both ends. Maximum. At the second time t2, the displacement of the ultrasonic horn 22 in the ultrasonic vibration direction A2 is maximized at both ends in the ultrasonic vibration direction A, and the displacement in the ultrasonic vibration direction one A1 is centered between the both ends. Maximum.

  Among the points in the ultrasonic horn 22, there is a point that vibrates most in the ultrasonic vibration direction A during resonance. The stationary position of the most vibrating point is referred to as a resonance antinode position in the ultrasonic horn 22. In the present embodiment, both ends P1, P2 in the ultrasonic vibration direction A of the ultrasonic horn 22 and the center P3 between the both ends are the antinode positions. The antinode portion of the ultrasonic horn 22 has a smaller pressure change than the remaining portion, and therefore vibration in a direction perpendicular to the ultrasonic vibration direction A due to the pressure change is small.

  Among the points in the ultrasonic horn 22, there are points that do not vibrate in the ultrasonic vibration direction A during resonance. The stationary position of the point that does not vibrate is called a resonance node position in the ultrasonic horn 22. In the present embodiment, the position P4 that is closer to the other end by a quarter wavelength from one end of the ultrasonic horn 22 in the ultrasonic vibration direction A and the other end of the ultrasonic horn 22 in the ultrasonic vibration direction A 1 / A position P5 that is closer to one end by four wavelengths is a node position. The portion of the node position of the ultrasonic horn 22 has the largest pressure change, and therefore the vibration in the direction perpendicular to the ultrasonic vibration direction A caused by the pressure change is the largest.

  According to the present embodiment as described above, both ends 22 a and 22 b of the ultrasonic horn 22 in the ultrasonic vibration direction A are supported by the support means 26. The both end portions 22 a and 22 b of the ultrasonic horn 22 are portions of the antinode position of the ultrasonic horn 22. The portion at the antinode position of the ultrasonic horn 22 has less vibration in the direction perpendicular to the ultrasonic vibration direction A than the remaining portion. Therefore, the problem that the semiconductor chip 23 vibrates in a direction perpendicular to the semiconductor chip 23 in the pressed state can be suppressed as much as possible. Therefore, damage to the semiconductor chip 23 can be prevented.

  The both end portions 22a and 22b of the ultrasonic horn 22 are portions of the antinode of the ultrasonic horn 22, and therefore vibrate in the ultrasonic vibration direction A. Considering this, the both end portions 22a and 22b of the ultrasonic horn 22 are supported by the support means 26 so that the both end portions 22a and 22b of the ultrasonic horn 22 can vibrate in the ultrasonic vibration direction A. Thereby, the vibration of the both end portions 22a and 22b of the ultrasonic horn 22 is allowed, and the influence of the support means 26 that supports the ultrasonic horn 22 on the resonance of the ultrasonic horn 22 can be suppressed.

  The ultrasonic transducer 25 is arranged at a position closer to the other end by a quarter wavelength from one end in the ultrasonic vibration direction A of the ultrasonic horn 22. This position is a node position of the ultrasonic horn 22. The minute vibration at the node position of the ultrasonic horn 22 becomes large vibration at the antinode position of the ultrasonic horn 22. Therefore, the ultrasonic vibration of the ultrasonic vibrator 25 can be used effectively, and the transmission efficiency of the ultrasonic vibration can be improved.

  Moreover, the ultrasonic transducer 25 is built in the ultrasonic horn 22 with both end portions 25 a and 25 b in the ultrasonic vibration direction A in contact with the ultrasonic horn 22. As described above, since the ultrasonic vibrator 25 is supported from both sides in the ultrasonic vibration direction A, it is possible to prevent a problem that the ultrasonic vibrator 25 is displaced during ultrasonic vibration. Thereby, the stability of resonance can be improved, and the semiconductor chip 23 and the circuit board 24 can be reliably flip-chip bonded. In addition, since the above-mentioned problem is prevented, the ultrasonic vibration of the ultrasonic vibrator 25 can be used more effectively, and the transmission efficiency of the ultrasonic vibration can be further improved.

  In this embodiment, the semiconductor chip 23 and the circuit board 24 can be reliably flip-chip bonded without damaging the semiconductor chip 23. Therefore, the yield can be improved and the production cost can be reduced.

  Further, according to the present embodiment, the both end portions 22a and 22b in the ultrasonic vibration direction A of the ultrasonic horn 22 are portions of the antinodes of resonance, and the ultrasonic horn 22 is supported by the support means 26. Therefore, the ultrasonic horn 22 and the support means 26 can be easily connected by fastening using a bolt member.

  Further, according to the present embodiment, the inertial mass of the ultrasonic horn 22 is selected to be 1.0% or less of the inertial mass of the entire bonding apparatus 21. When the ultrasonic horn 22 resonates, the center of gravity does not change, but the antinode portion vibrates in the ultrasonic vibration direction A. Therefore, vibration is transmitted to the support means 26. Due to this vibration, the remaining part other than the ultrasonic horn 22 in the entire bonding apparatus 21 may vibrate.

  In particular, as in the present embodiment, when the distance between the support members 31a and 31b corresponds to a length that is a natural number times the wavelength of the ultrasonic wave, the ultrasonic horn 22 connected to the support members 31a and 31b. Both end portions 22a and 22b in the ultrasonic vibration direction A of the same vibrate in the same direction. Therefore, the remaining part may vibrate.

  When the inertial mass of the ultrasonic horn 22 exceeds 1.0% of the inertial mass of the entire bonding apparatus 21, the remaining portion vibrates with the resonance of the ultrasonic horn 22. If the inertial mass of the ultrasonic horn 22 is 1.0% or less of the total inertial mass of the bonding apparatus 21, the problem that the remaining portion vibrates with the resonance of the ultrasonic horn 22 can be prevented.

  Furthermore, when the movable body 73 has a rigid structure with the base 72, the inertial mass of the remaining portion can be regarded as an inertial mass combining the movable body 73 and the base 72. On the other hand, when the movable body 73 is flexibly attached to the base 72, the inertia mass of the remaining portion should be regarded as the inertia mass of the movable body 73. In this case, the inertial mass of the ultrasonic horn 22 is selected to be sufficiently smaller (two digits or more) than the inertial mass of the movable body 73. Specifically, the inertial mass of the ultrasonic horn 22 is selected to be 1% or less of the inertial mass of the movable body 73.

  Further, according to the present embodiment, the support members 31 a and 31 b are connected to the both end portions 22 a and 22 b of the ultrasonic horn 22 and extend in the pressing direction B <b> 1 of the semiconductor chip 23. A holder 33 is connected to the ends of the support members 31a and 31b opposite to the side connected to the ultrasonic horn 22 via the connection members 32a and 32b. The circuit board substrate 28 is located at a position retracted in the direction B2 opposite to the pressing direction B1 from the ends 68, 69 opposite to the side connected to the ultrasonic horn 22 of the support members 31a, 31b. 24 is held. The substrate holding body 28 can be enlarged and the inertial mass of the substrate holding body 28 can be increased without increasing the size of the entire bonding apparatus 21.

  By increasing the inertial mass of the substrate holder 28 in this way, it is possible to suppress the vibration of the substrate holder 28 that occurs during ultrasonic flip chip bonding. As a result, a decrease in relative vibration between the semiconductor chip 23 and the circuit board 24 can be suppressed, and the semiconductor chip 23 and the circuit board 24 can be reliably flip-chip bonded. Therefore, a module having high reliability can be obtained, and the yield can be improved.

  Table 1 shows the shear strength and the rate of occurrence of breakage of the semiconductor chip for the samples prepared using the bonding apparatus 21 of the present embodiment and the conventional bonding apparatus, respectively. Using the bonding apparatus 21 of the present embodiment, 50 samples were created under predetermined bonding conditions. For comparison, 50 samples were prepared using the conventional joining apparatus as shown in FIG. 8 under the same joining conditions as the predetermined joining conditions. From each of these samples, the shear strength and the breakage rate of the semiconductor chip were determined. For the preparation of the sample, the following semiconductor chip and circuit board were used.

  The external dimensions of the semiconductor chip are 10 × 10 × 0.1 (mm). 350 electrodes are formed on one surface of the semiconductor chip. Each electrode is formed by sputtering and is made of aluminum. Each electrode is 90 μm square and has a thickness of 1 μm. Each electrode is provided with a gold ball bump having a diameter of 60 μm and a height of 30 μm.

  The external dimensions of the circuit board are 14 × 14 × 0.1 (mm). The circuit board is made of a glass epoxy board or the like, and 350 electrodes are formed on one surface of the circuit board. Each electrode is formed by sequentially plating nickel (Ni) and gold (Au) on a copper wiring formed on one surface of a circuit board. The gold formed on the outermost layer is formed to a thickness of 0.5 μm, for example, by electroless plating.

  In joining the semiconductor chip and the circuit board, after positioning the semiconductor chip and the circuit board, pressurization to each bump provided on the semiconductor chip is started, and the applied pressure per bump reaches 30 MPa. Then, ultrasonic vibration was started. The ultrasonic output was 1 W, and this output was maintained for 500 ms. The applied pressure per bump was finally increased to 90 MPa.

  In measuring the shear strength, after the semiconductor chip and the circuit board were flip-chip bonded, first, the semiconductor chip was removed leaving each bump. And the shear strength of the junction part of each bump and each electrode of a circuit board was measured using the shear tool. The shear strength of the joint corresponds to the joint strength.

  As shown in Table 1, when the conventional joining apparatus was used, although the shear strength was sufficiently high, breakage such as disconnection was found in 8 out of 50 pieces. On the other hand, when the bonding apparatus 21 of the present embodiment was used, a higher shear strength was obtained than when the conventional bonding apparatus was used, and the semiconductor chip was not damaged.

  Table 2 shows the shear strength and the occurrence rate of breakage of the semiconductor chip when the ultrasonic output is lowered. Using the bonding apparatus 21 of the present embodiment, 50 samples were created under the bonding conditions similar to the predetermined bonding conditions. The difference from the predetermined joining condition is that the ultrasonic output is 500 mW, which is half of 1W. From each of the prepared samples, the shear strength and the breakage rate of the semiconductor chip were determined.

  As shown in Table 2, even when the ultrasonic output was lowered to 500 mW, the same shear strength as that obtained when the conventional joining apparatus shown in Table 1 was used was obtained. Therefore, when the bonding apparatus 21 of the present embodiment is used, the transmission efficiency of ultrasonic vibration is improved by about twice as compared with the conventional bonding apparatus, and the flip chip bonding can be performed with low ultrasonic energy. It turns out that it is possible. Even when the ultrasonic output was lowered to 500 mW, the semiconductor chip was not damaged.

  The above-described embodiment is merely an example of the present invention, and the configuration can be changed within the scope of the present invention. The connection between the ultrasonic horn 22 and the support members 31a and 31b only needs to be able to be firmly fixed, and the ultrasonic horn 22 and the support members 31a and 31b may be connected by welding, for example. The same applies to the connection between the support members 31 a and 31 b and the connection members 32 a and 32 b and the connection between the connection members 32 a and 32 b and the holder 33.

  The ultrasonic transducer 25 is not limited to a piezoelectric element, and may be a magnetostrictive element, for example. The material of the ultrasonic horn 22 is not limited to iron, and may be, for example, an aluminum alloy, brass, stainless steel, or titanium alloy.

  The ultrasonic horn 22 has one of a length that is a natural number multiple of the ultrasonic wavelength and a length that is a natural multiple of the ultrasonic wavelength plus a half wavelength of the ultrasonic wave in the ultrasonic vibration direction A. What is necessary is just to have length. When there are a plurality of resonance node positions in the ultrasonic horn 22, the ultrasonic transducer 25 is arranged at a node position farthest from the chip holder 27 among the plurality of node positions. Accordingly, the influence of the ultrasonic transducer 25 from the chip holder 27 can be suppressed.

  The circuit board 24 may be heated by a heating means at the time of ultrasonic flip chip bonding. In this case, the temperature of the circuit board 24 may be measured by a thermometer, and the control unit 84 may determine the bonding time based on the timer measurement result and the thermometer measurement result.

  When the circuit board 24 is heated, the chip holder 27 is also heated via the bumps and the semiconductor chip 23. Considering this, as described above, the ultrasonic transducer 25 and the chip holder 27 are arranged at the node position farthest from the chip holder 27 among the plurality of node positions. Increase the distance between.

  Thus, by increasing the distance between the ultrasonic transducer 25 and the chip holder 27, the problem that the ultrasonic transducer 25 is also heated is prevented. Further, by increasing the distance between the ultrasonic transducer 25 and the chip holder 27 and using a cooling means such as a cooling fan, the wind is sent to the portion around the ultrasonic transducer 25 in the ultrasonic horn 22. In addition, the problem that even the ultrasonic transducer 25 is heated can be prevented more reliably. The cooling means is attached to the holder 33, for example.

  As described above, since the problem that even the ultrasonic transducer 25 is heated is prevented, a piezoelectric element having low heat resistance can be used as the ultrasonic transducer 25.

It is a figure for demonstrating the structure of the ultrasonic flip-chip bonding apparatus 21 of one Embodiment of this invention. It is a perspective view which shows the supporting member 31a. 4 is an enlarged cross-sectional view showing one end portion 22a of an ultrasonic horn 22 in an ultrasonic vibration direction A. FIG. 3 is a cross-sectional view of a chip holder 27. 1 is a front view showing a simplified overall configuration of a bonding apparatus 21. FIG. 3 is a block diagram showing an electrical configuration of a joining device 21. FIG. 4 is a flowchart for explaining a joining operation of the joining device 21. It is a front view which simplifies and shows the structure of the ultrasonic bonding apparatus 1 of the 2nd prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Ultrasonic flip chip bonding apparatus 22 Ultrasonic horn 23 Semiconductor chip 24 Circuit board 25 Ultrasonic transducer 26 Support means 27 Chip holder 28 Substrate holder 29 Press means 31a, 31b Support members 32a, 32b Connecting member 33 Holder

Claims (6)

An ultrasonic flip chip bonding apparatus for flip chip bonding a semiconductor chip and a circuit board using ultrasonic vibration,
An ultrasonic vibrator that vibrates ultrasonically;
An ultrasonic horn that resonates in the direction of ultrasonic vibration by ultrasonic vibration by an ultrasonic vibrator;
Support means for supporting the ultrasonic horn;
A chip holder that is provided in the ultrasonic horn and holds the semiconductor chip in parallel with the ultrasonic vibration direction;
A substrate holder for holding the circuit board in parallel with the semiconductor chip held by the chip holder;
Pressing means for pressing the semiconductor chip held by the chip holder against the circuit board held by the substrate holder,
The support means supports the antinode portion of the ultrasonic horn so that the antinode portion of the resonance of the ultrasonic horn can vibrate in the ultrasonic vibration direction.
The ultrasonic vibrator is disposed at a resonance node position in the ultrasonic horn, and is provided in the ultrasonic horn with both ends in the ultrasonic vibration direction being in contact with the ultrasonic horn. apparatus. When there are multiple resonance node positions in the ultrasonic horn,
2. The ultrasonic flip-chip bonding apparatus according to claim 1, wherein the ultrasonic transducer is disposed at a node position farthest from the chip holder among the plurality of node positions.   3. The ultrasonic flip-chip bonding apparatus according to claim 1, wherein the supporting means supports both ends of the ultrasonic horn in the ultrasonic vibration direction.   The ultrasonic flip-chip bonding apparatus according to any one of claims 1 to 3, wherein an inertial mass of the ultrasonic horn is selected to be 1.0% or less of an inertial mass of the entire apparatus. Support means are
A support member connected to the antinode portion of the ultrasonic horn and extending in the pressing direction of the semiconductor chip, and having flexibility in the ultrasonic vibration direction;
A holder connected to the end of the support member opposite to the side connected to the ultrasonic horn,
The substrate holder holds the circuit board at a position retracted in a direction opposite to the pressing direction of the semiconductor chip from an end of the support member opposite to the side connected to the ultrasonic horn. The ultrasonic flip chip bonding apparatus according to any one of claims 1 to 4. An ultrasonic flip chip bonding apparatus for flip chip bonding a semiconductor chip and a circuit board using ultrasonic vibration,
An ultrasonic vibrator that vibrates ultrasonically;
An ultrasonic horn that resonates in the direction of ultrasonic vibration by ultrasonic vibration by an ultrasonic vibrator;
A chip holder that is provided in the ultrasonic horn and holds the semiconductor chip in parallel with the ultrasonic vibration direction;
A substrate holder for holding the circuit board in parallel with the semiconductor chip held by the chip holder;
Pressing means for pressing the semiconductor chip held by the chip holder against the circuit board held by the substrate holder,
The ultrasonic transducer is arranged at a resonance node position in the ultrasonic horn, and is provided in the ultrasonic horn with both ends in the ultrasonic vibration direction being in contact with the ultrasonic horn. apparatus.

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