Horn and bonding tool

Abstract

A horn (10) is provided with: a block part (20) which is arranged aligned with a vibrator (2) in a first direction; transmission parts (30), (40) which are arranged between the block part and the vibrator in a first direction and transmit vibration (F) from the vibrator to the block part; and a reflection part (50) which is arranged on the opposite side of the block part from the transmission parts in the first direction and reflects the vibration from the block part.

Description

Horns and Bonding Tools

[0001] The present disclosure relates to a horn and a bonding tool.

[0002] For example, Patent Document 1 discloses a horn applied to a bonding tool. A semiconductor element is attached to the suction surface of the horn as an object to be attached. Electrodes are provided on the semiconductor element, and bumps are formed on the electrodes. Electrodes are provided on a substrate. The electrodes on the semiconductor element attached to the suction surface of the horn are aligned with the electrodes on the substrate via the bumps. When the horn is vibrated in this state by a vibrator, the bumps are plastically deformed. As a result, the electrodes on the semiconductor element attached to the suction surface of the horn are bonded to the electrodes on the substrate via the bumps.

[0003] Patent No. 5426762

[0004] However, the suction surface of the horn can become wavy or tilted, which can easily lead to poor bonding when electrodes on a semiconductor element held to the suction surface of the horn are bonded to electrodes on a substrate via bumps.

[0005] The present disclosure has been made in view of the above points, and its purpose is to suppress waviness and tilting on the suction surface of the horn.

[0006] The horn according to the present disclosure comprises a block portion arranged in line with a vibrator in a first direction; a transmission portion arranged between the block portion and the vibrator in the first direction and transmitting vibrations from the vibrator to the block portion; and a reflection portion arranged on the opposite side of the block portion in the first direction from the transmission portion and reflecting the vibrations from the block portion, wherein the block portion includes an adsorption surface facing one side of a second direction intersecting the first direction and having an adsorption portion that adsorbs an object to be adsorbed, and a back surface facing the other side of the second direction opposite to the adsorption surface, the vibrator has a central axis extending in the first direction, and the block portion includes adsorption surface slope portions inclined with respect to the central axis at the connection portion of the adsorption surface to the transmission portion and the connection portion of the adsorption surface to the reflection portion, and the block portion is configured asymmetrically with respect to the central axis.

[0007] The bonding tool according to the present disclosure comprises the horn, the vibrator, and a stage on which a substrate having a substrate-side electrode is placed, and aligns the horn-side electrode provided on the semiconductor element as the object to be attached with the substrate-side electrode via a bump, and then applies the vibration to the horn using the vibrator, thereby bonding the horn-side electrode to the substrate-side electrode via the bump.

[0008] According to the present disclosure, it is possible to suppress waviness and tilting of the suction surface of the horn.

[0009] FIG. 1 shows a front cross-sectional view of a bonding tool including an ultrasonic horn according to a first embodiment. FIG. 2 shows a front cross-sectional view of the ultrasonic horn according to the first embodiment. FIG. 3 shows a plan cross-sectional view of the ultrasonic horn according to the first embodiment. FIG. 4 shows the relationship between the position and displacement in the front-rear direction of the ultrasonic horn according to the first embodiment. FIG. 5 shows the relationship between the position in the front-rear direction and the displacement in the up-down direction of the ultrasonic horn according to the first embodiment. FIG. 6 shows the suppression of tilt of the ultrasonic horn according to the first embodiment. FIG. 7 shows a front cross-sectional view of the ultrasonic horn according to the second embodiment. FIG. 8 shows a front cross-sectional view of the ultrasonic horn according to the third embodiment. FIG. 9 shows a front cross-sectional view of the ultrasonic horn according to the fourth embodiment. FIG. 10 shows a front cross-sectional view of the ultrasonic horn according to the fifth embodiment. FIG. 11 shows a front cross-sectional view of the ultrasonic horn according to the sixth embodiment.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0011] <First embodiment> (Ultrasonic horn) An ultrasonic horn 10 as a horn according to the first embodiment will be described. The ultrasonic horn 10 is applied to a bonding tool 1. Fig. 1 shows a front cross-sectional view of the bonding tool 1 equipped with the ultrasonic horn 10. Fig. 2 shows a front cross-sectional view of the ultrasonic horn 10. Fig. 3 shows a plan cross-sectional view of the ultrasonic horn 10.

[0012] In the following description, the left-right direction in FIG. 1 is referred to as the front-to-back direction (indicated by X) as the first direction, the direction perpendicular to the paper surface in FIG. 1 is referred to as the left-to-right direction (indicated by Y) as the third direction, and the up-to-down direction in FIG. 1 is referred to as the up-to-down direction (indicated by Z) as the second direction.

[0013] The right side of Fig. 1 is the front (indicated by Xa) as one of the first directions, and the left side of Fig. 1 is the rear (indicated by Xb) as the other of the first directions. The bottom of Fig. 1 is the bottom (indicated by Za) as one of the second directions, and the top of Fig. 1 is the top (indicated by Zb) as the other of the second directions. The front-to-back direction, the left-to-right direction, and the up-to-down direction intersect (specifically, are perpendicular to) each other.

[0014] As shown in FIG. 1, the bonding tool 1 includes an ultrasonic horn 10 , a vibrator 2 , a rib 3 , a head 4 , and a stage 5 .

[0015] The ultrasonic horn 10 is configured to be longitudinal in the front-to-rear direction. The ultrasonic horn 10 and the vibrator 2 are arranged side by side in the front-to-rear direction. The vibrator 2 is connected to the front end of the ultrasonic horn 10. The ultrasonic horn 10 is made of, for example, metal.

[0016] As shown in FIG. 2, the ultrasonic horn 10 includes a core block 20 as a block portion, a front side block 30 as a part of the transmission portion, a front connecting block 40 as a part of the transmission portion, a rear side block 50 as a part of the reflection portion, and a rear connecting block 60 as a part of the reflection portion.

[0017] In the ultrasonic horn 10, the front side block 30, the front connecting block 40, the core block 20, the rear connecting block 60, and the rear side block 50 are arranged in this order from front to rear in the longitudinal direction.

[0018] The core block 20 is formed in a substantially rectangular parallelepiped shape. The core block 20 is configured so that its length is in the front-rear direction. The core block 20 is arranged next to the vibrator 2 in the front-rear direction. The core block 20 is arranged rearward of the vibrator 2, with the front side block 30 and the front connecting block 40 sandwiched between them.

[0019] The front side block 30 and the front connecting block 40 are disposed between the core block 20 and the transducer 2 in the front-to-rear direction. The front side block 30 and the front connecting block 40 are connected to each other in the front-to-rear direction. The front side block 30 and the front connecting block 40 connect the core block 20 and the transducer 2 in the front-to-rear direction.

[0020] The front side block 30 constitutes the front end of the ultrasonic horn 10. The front side block 30 is disposed rearward of the transducer 2 and forward of the front connecting block 40 in the front-to-rear direction. A screw hole 31 is formed at the front end of the front side block 30 to receive a screw for attaching the transducer 2. The front side block 30 is formed in a substantially rectangular parallelepiped shape. The front side block 30 is configured to be elongated in the front-to-rear direction. The front side block 30 is smaller than the core block 20.

[0021] The front connecting block 40 is disposed rearward of the front side block 30 and forward of the core block 20 in the front-to-rear direction. The front connecting block 40 is connected to the front end of the core block 20. The front connecting block 40 is formed in a substantially rectangular parallelepiped shape. The front connecting block 40 is configured with its longitudinal axis extending in the front-to-rear direction. The front connecting block 40 has a smaller cross-sectional area, as viewed in the front-to-rear direction, than the front side block 30 (and of course, the cross-sectional area, as viewed in the front-to-rear direction, is smaller than that of the core block 20).

[0022] The rear side blocks 50 and the rear connecting blocks 60 are arranged on the opposite side of the front side blocks 30 and the front connecting blocks 40 in the front-to-rear direction, with the core block 20 sandwiched between them. The rear side blocks 50 and the rear connecting blocks 60 are arranged on the opposite side of the vibrator 2 in the front-to-rear direction, with the core block 20 and the front side blocks 30 and the front connecting blocks 40 sandwiched between them. The rear side blocks 50 and the rear connecting blocks 60 are connected to each other in the front-to-rear direction.

[0023] The rear side block 50 constitutes the rear end of the ultrasonic horn 10. The rear side block 50 is disposed rearward of the core block 20 in the front-to-rear direction, with the rear connecting block 60 sandwiched between them. The rear side block 50 is formed in a substantially rectangular parallelepiped shape. The rear side block 50 is configured to be longitudinal in the front-to-rear direction. The rear side block 50 is smaller than the core block 20.

[0024] The rear connecting block 60 is positioned rearward of the core block 20 and forward of the rear side block 50 in the front-to-rear direction. The rear connecting block 60 is connected to the rear end of the core block 20. The rear connecting block 60 is formed in a substantially rectangular parallelepiped shape. The rear connecting block 60 is configured with its longitudinal axis extending in the front-to-rear direction. The cross-sectional area of ​​the rear connecting block 60, as viewed in the front-to-rear direction, is smaller than that of the rear side block 50 (and of course, the cross-sectional area, as viewed in the front-to-rear direction, is smaller than that of the core block 20).

[0025] The front side block 30 and the rear side block 50 have the same shape and size. The front connecting block 40 and the rear connecting block 60 have the same shape and size.

[0026] As shown in Figure 3, ribs 3 are provided on the left and right side surfaces of the front connecting block 40 of the ultrasonic horn 10. Ribs 3 are provided on the left and right side surfaces of the rear connecting block 60 of the ultrasonic horn 10. The ribs 3 are configured in a generally L-shape, extending outward to the left and right and then upward.

[0027] As shown in Figure 1, the upper end of the rib 3 is connected to the head 4. The head 4 is movable in all directions. The ultrasonic horn 10 is connected to the head 4 via the rib 3. The ultrasonic horn 10 moves in all directions as the head 4 moves.

[0028] The vibrator 2 is composed of, for example, a piezoelectric element. The vibrator 2 is fixed to the front end of the front side block 30 of the ultrasonic horn 10 with a screw. The vibrator 2 generates vibrations. The vibrations generated by the vibrator 2 are longitudinal vibrations (longitudinal waves, compressional waves) whose traveling direction and amplitude direction are in the front-to-rear direction. The vibrations generated by the vibrator 2 are ultrasonic vibrations F.

[0029] The transducer 2 is substantially cylindrical and has a central axis O. The central axis O extends in the front-rear direction. The front-rear direction in which the central axis O extends coincides with the direction of propagation and amplitude of ultrasonic vibration F generated by the transducer 2.

[0030] The ultrasonic vibrations F from the vibrator 2 are transmitted to the ultrasonic horn 10. In the front-to-rear direction, the ultrasonic vibrations F from the vibrator 2 are first transmitted rearward toward the front side block 30, then transmitted rearward toward the front connecting block 40, and then transmitted rearward toward the core block 20. In other words, the front side block 30 and the front connecting block 40 transmit the ultrasonic vibrations F from the vibrator 2 to the core block 20 in the front-to-rear direction.

[0031] The ultrasonic vibrations F transmitted to the core block 20 are transmitted rearward in the front-to-rear direction toward the rear connecting block 60, and then transmitted rearward toward the rear side block 50. The ultrasonic vibrations F transmitted to the rear side block 50 are reflected at the rear end of the rear side block 50. The ultrasonic vibrations F reflected at the rear end of the rear side block 50 are transmitted forward toward the rear connecting block 60, and then transmitted forward toward the core block 20. In other words, the rear side block 50 and the rear connecting block 60 reflect the rearward ultrasonic vibrations F from the core block 20 forward.

[0032] The front connecting block 40 and the rear connecting block 60 have a smaller cross-sectional area in the front-to-rear direction than the core block 20 and the front side block 30 and the rear side block 50. In the front connecting block 40 and the rear connecting block 60, the ultrasonic vibration F is amplified.

[0033] 1, a substrate W1 is placed on the upper surface of the stage 5. The upper surface of the stage 5 faces upward and extends straight in the front-rear and left-right directions. The thickness direction of the substrate W1 is the up-down direction, and the substrate W1 also extends straight in the front-rear and left-right directions. The substrate W1 is, for example, a semiconductor substrate.

[0034] A substrate-side electrode E1 is provided on the upper surface of the substrate W1. The substrate-side electrode E1 is made of, for example, a metal.

[0035] As shown in Figure 2, the core block 20 includes an adsorption surface 21 and a rear surface 22. The adsorption surface 21 faces downward. The adsorption surface 21 extends straight in the front-rear and left-right directions. The adsorption surface 21 is on the opposite side of the rear surface 22 in the up-down direction. The adsorption surface 21 is located below the central axis O of the vibrator 2.

[0036] The rear surface 22 faces upward. The rear surface 22 is located on the opposite side of the adsorption surface 21 in the up-down direction. The rear surface 22 extends straight in the front-rear and left-right directions. The rear surface 22 is located above the central axis O of the vibrator 2.

[0037] A passage 23 is provided inside the core block 20. The passage 23 penetrates the core block 20 in the vertical direction. An upper portion of the passage 23 is formed by a large diameter portion 23a. A lower portion of the passage 23 is formed by a small diameter portion 23b that is smaller in diameter than the large diameter portion 23a. In the core block 20, the upper end of the large diameter portion 23a of the passage 23 opens to the back surface 22. In the core block 20, the lower end of the small diameter portion 23b of the passage 23 opens to the suction surface 21.

[0038] The passage 23 is disposed in a central portion C in the front-rear direction of the ultrasonic horn 10. In particular, the passage 23 is disposed in a central portion C in the front-rear direction of the core block 20.

[0039] The upper end of the large diameter portion 23a of the passage 23, which opens to the back surface 22 of the core block 20, is connected to a vacuum pump (not shown). The lower end of the small diameter portion 23b of the passage 23, which opens to the suction surface 21 of the core block 20, forms a suction hole 24 as a suction portion. In other words, the suction hole 24 is provided in the suction surface 21 of the core block 20.

[0040] When the vacuum pump is driven, air flows through the passage 23 from the suction surface 21 to the back surface 22. The suction holes 24 in the suction surface 21 of the core block 20 suction-hold the semiconductor element W2 as an object to be suctioned. A horn-side electrode E2 is provided on the underside of the semiconductor element W2. The semiconductor element W2 is a component of an electronic circuit made of semiconductors and is also called a semiconductor device. The horn-side electrode E2 is made of, for example, metal.

[0041] Horn-side electrodes E2 provided on semiconductor element W2 are bonded to substrate-side electrodes E1 provided on the upper surface of substrate W1 via bumps B. Bumps B are formed in a protruding shape and are made of, for example, metal.

[0042] The bonding tool 1 aligns the horn-side electrode E2 provided on the semiconductor element W2, which is sucked onto the suction surface 21 of the core block 20 of the ultrasonic horn 10, with the substrate-side electrode E1 provided on the upper surface of the substrate W via the bump B, and applies ultrasonic vibrations F to the ultrasonic horn 10 in the forward and backward directions using the vibrator 2, thereby plastically deforming the bumps B and bonding the horn-side electrode E2 to the substrate-side electrode E1 via the bumps B. The suction surface 21 of the core block 20 vibrates as a standing wave of the ultrasonic vibrations F.

[0043] The central axis O of the vibrator 2 passes through the center of the front side block 30, the center of the front connecting block 40, the center of the rear connecting block 60, and the center of the rear side block 50. The outer shapes of the front side block 30, the outer shapes of the front connecting block 40, the outer shapes of the rear connecting block 60, and the outer shapes of the rear side block 50 are configured symmetrically (specifically, line-symmetrically) with respect to the central axis O of the vibrator 2.

[0044] On the other hand, although details will be described later, the outer shape of the core block 20 is configured to be asymmetric (specifically, non-axially symmetric) with respect to the central axis O of the vibrator 2 .

[0045] The core block 20 includes an adsorption surface slope portion 25. In the core block 20, the adsorption surface slope portion 25 is formed at a connection portion of the adsorption surface 21 to the front connecting block 40 (transmission portion) and at a connection portion of the adsorption surface 21 to the rear connecting block 60 (reflection portion). In the core block 20, the adsorption surface slope portion 25 is formed at both ends (front end and rear end) of the adsorption surface 21 in the front-to-rear direction. The adsorption surface 21, the front connecting block 40, and the rear connecting block 60 are connected to each other via the adsorption surface slope portion 25.

[0046] The suction surface slope portion 25 is inclined at an suction surface slope angle D1, which is an angle on the suction surface side, with respect to the central axis O of the vibrator 2. The suction surface slope angle D1 is the angle formed between the suction surface slope portion 25 and the central axis O of the vibrator 2. The suction surface slope angle D1 is preferably less than 90°. The suction surface slope angle D1 is preferably 30° or greater and 60° or less. The suction surface slope angle D1 is particularly preferably 30° or greater and 45° or less. In this example, the suction surface slope portion 25 extends obliquely and straight (linearly). The suction surface slope angle D1 is constant.

[0047] The core block 20 includes a back surface slope portion 26. In the core block 20, the back surface slope portion 26 is formed at a connecting portion of the back surface 22 to the front connecting block 40 (transmission portion) and at a connecting portion of the back surface 22 to the rear connecting block 60 (reflection portion). In the core block 20, the back surface slope portion 26 is formed at both ends (front end and rear end) of the back surface 22 in the front-to-rear direction. The back surface 22, the front connecting block 40, and the rear connecting block 60 are connected to each other via the back surface slope portion 26.

[0048] The back surface slope portion 26 is inclined at a back surface slope angle D2, which is a back surface angle, with respect to the central axis O of the vibrator 2. The back surface slope angle D2 is the angle formed between the back surface slope portion 26 and the central axis O of the vibrator 2. The back surface slope angle D2 is preferably less than 90°. In this example, the back surface slope angle D2 and the suction surface slope angle D1 are equal to each other. In this example, the back surface slope portion 26 extends diagonally and straight (in a straight line). The back surface slope angle D2 is constant.

[0049] The starting points of the suction surface slope portion 25 on the front connecting block 40 (transmission portion) side and the rear connecting block 60 (reflection portion) side are defined as suction surface starting points P1. The starting points of the rear slope portion 26 on the front connecting block 40 (transmission portion) side and the rear connecting block 60 (reflection portion) side are defined as rear surface starting points P2.

[0050] The suction surface side starting point P1 and the back surface side starting point P2 are located at positions that are the same distance in the front-to-rear direction from the center C of the core block 20. The distance in the front-to-rear direction between the suction surface side starting point P1 and the center C of the core block 20 is equal to the distance in the front-to-rear direction between the back surface side starting point P2 and the center C of the core block 20.

[0051] The adsorption surface side distance Z1, which is the distance in the vertical direction between the adsorption surface 21 of the core block 20 and the central axis O of the vibrator 2, is larger than the back surface side distance Z2, which is the distance in the vertical direction between the back surface 22 of the core block 20 and the central axis O of the vibrator 2.

[0052] As described above, the attraction surface side distance Z1 is greater than the back surface side distance Z2. That is, the core block 20 is configured asymmetrically (specifically, non-axially symmetrically) with respect to the central axis O of the vibrator 2. The shape of the core block 20 is asymmetrically (specifically, non-axially symmetrically) between the region below the central axis O and the region above the central axis O.

[0053] 4 shows the relationship between the position and displacement of the ultrasonic horn 10 in the front-to-rear direction. The horizontal axis indicates the position of the ultrasonic horn 10 in the front-to-rear direction. The vertical axis indicates the displacement of the ultrasonic horn 10 in the front-to-rear direction (the upper side of the vertical axis is the front, and the lower side of the vertical axis is the rear). The vertical axis indicates the relative displacement in the front-to-rear direction at each position of the ultrasonic horn 10 in the front-to-rear direction.

[0054] 5 shows the relationship between the position in the front-to-rear direction and the displacement in the up-down direction of the ultrasonic horn 10. The horizontal axis shows the position in the front-to-rear direction of the ultrasonic horn 10. The vertical axis shows the displacement in the up-down direction of the ultrasonic horn 10. The vertical axis shows the relative displacement in the up-down direction at each position when the displacement in the up-down direction at the center C in the front-to-rear direction of the ultrasonic horn 10 is set to zero.

[0055] 5, the solid line indicates the simulation results for the ultrasonic horn 10 according to this embodiment, and the two-dot chain line indicates the simulation results for the conventional ultrasonic horn 10. In the conventional ultrasonic horn 10, the core block 20 does not include the suction surface slope portion 25 and the back surface slope portion 26.

[0056] In the conventional ultrasonic horn 10, the suction surface 21 of the core block 20 is connected to the front connecting block 40 and the rear connecting block 60 at a step (see the two-dot chain line in FIG. 5 ) perpendicular (90°) to the central axis O of the vibrator 2. In the conventional ultrasonic horn 10, both front and rear ends of the suction surface 21 of the core block 20 are corners.

[0057] In the ultrasonic horn 10 according to the conventional example, the rear surface 22 of the core block 20 is connected to the front connecting block 40 and the rear connecting block 60 at a step that is perpendicular (90°) to the central axis O of the vibrator 2. In the ultrasonic horn 10 according to the conventional example, both front and rear end portions of the rear surface 22 of the core block 20 are cornered.

[0058] The ultrasonic horn 10 according to this embodiment and the ultrasonic horn 10 according to the conventional example are identical in configuration other than that described above.

[0059] In the ultrasonic horn 10 according to the conventional example, when ultrasonic vibrations F are applied in the front-to-rear direction by the vibrator 2, the ultrasonic vibrations F as elastic waves of longitudinal vibrations (longitudinal waves, compressional waves) that oscillate in the front-to-rear direction are transmitted to each part of the ultrasonic horn 10. Each part of the ultrasonic horn 10 according to the conventional example undergoes expansion and contraction displacement in the front-to-rear direction due to the transmitted ultrasonic vibrations F, and the cross-sectional shape shrinks and expands in accordance with the expansion and contraction displacement in the front-to-rear direction (shrinks and expands in the left-to-right and up-to-down directions).

[0060] In the conventional ultrasonic horn 10, ultrasonic vibrations F are transmitted from the front connecting block 40 and rear connecting block 60, which have small cross-sectional areas, to the core block 20, which has a large cross-sectional area, spreading in the front-to-rear direction at a radiation angle of approximately 45° with respect to the central axis O. In the conventional ultrasonic horn 10, the cross-sectional area of ​​the core block 20 shrinks and expands (shrinks and expands in the left-right and up-down directions).

[0061] In the conventional ultrasonic horn 10, the core block 20 does not have an adsorption surface slope portion 25, and the adsorption surface 21 of the core block is connected to the front connecting block 40 and the rear connecting block 60 by steps perpendicular (90°) to the central axis O (both the front and rear ends of the adsorption surface 21 of the core block are corners). In the conventional ultrasonic horn 10, ultrasonic vibrations F with a radiation angle of approximately 45° are transmitted to the front-to-rear central portion of the adsorption surface 21 of the core block 20, but are not transmitted to the front-to-rear corners of both the front and rear ends of the adsorption surface 21 of the core block 20.

[0062] In the conventional ultrasonic horn 10, there is a difference in the degree of transmission of ultrasonic vibrations F between the front-to-rear center of the adsorption surface 21 of the core block 20 and the corners at both front and rear ends of the adsorption surface 21 of the core block 20. In the conventional ultrasonic horn 10, there is a difference in the degree of contraction / expansion of the cross-sectional area (contraction / expansion in the left-to-right and up-to-down directions) between the front-to-rear center of the adsorption surface 21 of the core block 20 and the corners at both front and rear ends of the adsorption surface 21 of the core block 20. In the conventional ultrasonic horn 10, there is a difference in the amount of displacement in the up-to-down direction between the front-to-rear center of the adsorption surface 21 of the core block 20 and the corners at both front and rear ends of the adsorption surface 21 of the core block 20.

[0063] In the conventional ultrasonic horn 10, the adsorption surface 21 of the core block 20 (particularly the corners at both front and rear ends of the adsorption surface 21) undulates up and down in the front-to-rear direction (see the two-dot chain line in FIG. 5). In the conventional ultrasonic horn 10, the vertical displacement of the core block 20 peaks at the corners at both front and rear ends of the adsorption surface 21 of the core block 20, causing the adsorption surface 21 to undulate (see the two-dot chain line in FIG. 5).

[0064] In the conventional ultrasonic horn 10, if the adsorption surface 21 of the core block 20 becomes wavy, when the horn side electrode E2 provided on the semiconductor element W2 adsorbed to the adsorption surface 21 of the core block 20 of the ultrasonic horn 10 is joined to the substrate side electrode E1 provided on the upper surface of the substrate W1 via a bump B, poor bonding is likely to occur due to uneven pressing force or uneven bonding area.

[0065] (Effects) In the ultrasonic horn 10 according to this embodiment, the core block 20 includes an adsorption surface slope portion 25. In the core block 20, the adsorption surface slope portion 25 is formed at a connection portion of the adsorption surface 21 to the front connecting block 40 and a connection portion of the adsorption surface 21 to the rear connecting block 60. The adsorption surface slope portion 25 is inclined at an adsorption surface slope angle D1 with respect to the central axis O of the vibrator 2.

[0066] In the ultrasonic horn 10 according to this embodiment, the ultrasonic vibrations F are transmitted from the front connecting block 40 and the rear connecting block 60, which have small cross-sectional areas, to the core block 20, which has a large cross-sectional area, spreading in the front-to-rear direction at a radiation angle of approximately 45° with respect to the central axis O. In the ultrasonic horn 10 according to this embodiment, the cross-sectional area of ​​the core block 20 shrinks and expands (shrinks and expands in the left-right and up-down directions).

[0067] In the ultrasonic horn 10 of this embodiment, ultrasonic vibrations F with a radiation angle of approximately 45° are transmitted to the central portion C in the front-to-back direction of the adsorption surface 21 of the core block 20, and are also smoothly transmitted along the adsorption surface slope portion 25 to both front-to-back ends of the adsorption surface 21 of the core block 20.

[0068] In the ultrasonic horn 10 of this embodiment, it is possible to suppress differences in the degree of transmission of ultrasonic vibrations F between the central portion C in the front-to-back direction of the adsorption surface 21 of the core block 20 and both ends in the front-to-back direction of the adsorption surface 21 of the core block 20.

[0069] In the ultrasonic horn 10 of this embodiment, there is no difference in the degree of contraction / expansion of the cross-sectional area (contraction / expansion in the left-right and up-down directions) between the central portion C in the front-to-back direction of the suction surface 21 of the core block 20 and both ends in the front-to-back direction of the suction surface 21 of the core block 20.

[0070] In the ultrasonic horn 10 of this embodiment, it is possible to suppress the difference in the amount of vertical displacement between the central portion C in the front-to-back direction of the suction surface 21 of the core block 20 and both ends in the front-to-back direction of the suction surface 21 of the core block 20.

[0071] In the ultrasonic horn 10 according to this embodiment, the suction surface 21 of the core block 20 is prevented from undulating up and down in the front-to-back direction (see the solid lines in FIG. 5 ). In the ultrasonic horn 10 according to this embodiment, the vertical displacement of the core block 20 peaks at the front connecting block 40 and the rear connecting block 60, and the suction surface 21 of the core block 20 changes smoothly in the front-to-back direction (see the solid lines in FIG. 5 ). In the ultrasonic horn 10 according to this embodiment, the vertical displacement of the core block 20 does not peak at the suction surface 21 of the core block 20, and the suction surface 21 of the core block 20 does not undulate.

[0072] In the ultrasonic horn 10 of this embodiment, the adsorption surface 21 of the core block 20 is not wavy, so when the horn side electrode E2 provided on the semiconductor element W2 adsorbed to the adsorption surface 21 of the core block 20 of the ultrasonic horn 10 is joined to the substrate side electrode E1 provided on the upper surface of the substrate W1 via the bump B, poor joining due to uneven pressing force or uneven joining area can be suppressed.

[0073] In the ultrasonic horn 10 according to this embodiment, the tilt of the suction surface 21 of the core block 20 is suppressed by a method described below. In the region where the core block 20 is pulled in the front-rear direction, the cross-sectional area of ​​the core block 20 is reduced (reduced in the left-right and up-down directions). In the region where the core block 20 is compressed in the front-rear direction, the cross-sectional area of ​​the core block 20 is expanded (reduced in the left-right and up-down directions).

[0074] Such a change in the cross-sectional area of ​​the core block 20 (displacement in the left-right and up-down directions) causes a tilt in the core block 20. In particular, the displacement of the core block 20 in the up-down direction causes a tilt in the adsorption surface 21 of the core block 20.

[0075] If the adsorption surface 21 of the core block 20 is tilted, poor bonding is likely to occur when the horn side electrode E2 provided on the semiconductor element W2 adsorbed to the adsorption surface 21 of the core block 20 of the ultrasonic horn 10 is joined to the substrate side electrode E1 provided on the upper surface of the substrate W1 via a bump B.

[0076] In the ultrasonic horn 10 according to this embodiment, the suction surface side distance Z1 between the suction surface 21 of the core block 20 and the central axis O of the vibrator 2 is greater than the back surface side distance Z2 between the back surface 22 of the core block 20 and the central axis O of the vibrator 2. In other words, the core block 20 is configured asymmetrically with respect to the central axis O of the vibrator 2.

[0077] In the ultrasonic horn 10 according to this embodiment, the core block 20 is configured asymmetrically with respect to the central axis O of the vibrator 2, thereby deliberately generating lateral vibrations (transverse waves) that oscillate in the vertical direction on the adsorption surface 21 of the core block 20.

[0078] 6 shows how tilting of the adsorption surface 21 of the core block 20 in the ultrasonic horn 10 is suppressed. In the ultrasonic horn 10 according to this embodiment, tilting of the adsorption surface 21 of the core block 20 can be suppressed by superimposing vertical lateral vibrations on the adsorption surface 21 of the core block 20 in the opposite direction (to the direction in which the adsorption surface 21 of the core block 20 tends to tilt) when the adsorption surface 21 of the core block 20 tends to tilt.

[0079] For example, as shown in the upper diagram of Figure 6, when compressive strain occurs in the front connecting block 40 of the ultrasonic horn 10, the compressive strain occurring in the back slope portion 26 is smaller than the compressive strain occurring in the suction surface slope portion 25. The front connecting block 40 undergoes upward bending deformation.

[0080] At this time, tensile strain occurs in the rear connecting block 60. As described above, the tensile strain occurring in the rear surface slope portion 26 is smaller than the tensile strain occurring in the suction surface slope portion 25. The rear connecting block 60 undergoes downward bending deformation.

[0081] Due to the bending deformation, vertical lateral vibrations acting to tilt the suction surface 21 of the core block 20 counterclockwise are superimposed on the suction surface 21 of the core block 20. The clockwise tilt of the suction surface 21 of the core block 20 caused by the change in the cross-sectional area of ​​the core block 20 (displacement in the left-right and up-down directions) is offset by the vertical lateral vibrations acting counterclockwise on the suction surface 21 of the core block 20.

[0082] The middle diagram of Fig. 6 shows a case where no distortion occurs in the ultrasonic horn 10. The bottom diagram of Fig. 6 shows a case where distortion occurs in the ultrasonic horn 10 in the opposite direction to that in the top diagram of Fig. 6.

[0083] As described above, the ultrasonic horn 10 according to this embodiment can suppress waviness of the suction surface 21 of the core block 20 and can also suppress tilt of the suction surface 21 of the core block 20. In other words, the suction surface 21 of the core block 20 can be vibrated in the front-to-rear direction parallel to the substrate W.

[0084] In the ultrasonic horn 10 of this embodiment, the adsorption surface 21 of the core block 20 is less likely to ripple or tilt, so that poor bonding can be prevented when the horn side electrode E2 provided on the semiconductor element W2 adsorbed to the adsorption surface 21 of the core block 20 of the ultrasonic horn 10 is joined to the substrate side electrode E1 provided on the upper surface of the substrate W1 via the bump B.

[0085] If the adsorption surface slope angle D1 is too small, the dimension of the core block 20 in the front-to-rear direction becomes too large, resulting in an increase in the weight of the core block 20. If the adsorption surface slope angle D1 is too large, the ultrasonic vibration F with a radiation angle of approximately 45° is not properly transmitted to the adsorption surface slope portion 25, making the adsorption surface slope portion 25 prone to undulation. Both of these concerns can be resolved by setting the adsorption surface slope angle D1 to be between 30° and 60°.

[0086] Second Embodiment An ultrasonic horn 10 according to a second embodiment will be described. In the following description, the same components as those in the above embodiment will be designated by the same reference numerals, and detailed description thereof may be omitted. Figure 7 shows a front cross-sectional view of the ultrasonic horn 10.

[0087] In this embodiment, the suction surface slope angle D1, which is the angle between the suction surface slope portion 25 and the central axis O of the vibrator 2, is smaller than the back surface slope angle D2, which is the angle between the back surface slope portion 26 and the central axis O of the vibrator 2.

[0088] The other configurations are the same as those of the first embodiment.

[0089] This embodiment provides the same effects as those of the first embodiment. Furthermore, not only are the adsorption surface side distance Z1 and the back surface side distance Z2 different from each other, but the adsorption surface slope angle D1 and the back surface slope angle D2 are also different from each other, so the core block 20 becomes even more asymmetric with respect to the central axis O of the vibrator 2. This is more advantageous in suppressing the tilt of the adsorption surface 21 of the core block 20.

[0090] Third Embodiment An ultrasonic horn 10 according to a third embodiment will be described. In the following description, the same components as those in the above embodiments will be designated by the same reference numerals, and detailed description thereof may be omitted. Figure 8 shows a front cross-sectional view of the ultrasonic horn 10 according to the third embodiment.

[0091] In this embodiment, the suction surface slope portion 25 extends in a curved shape. The back surface slope portion 26 also extends in a curved shape. The suction surface slope angle D1 of the suction surface slope portion 25 is not constant, but increases as it approaches the suction surface 21 of the core block 20. The back surface slope angle D2 of the back surface slope portion 26 is not constant, but increases as it approaches the back surface 22 of the core block 20.

[0092] The rate of increase of the attraction surface slope angle D1 is smaller than the rate of increase of the back surface slope angle D2.

[0093] The other configurations are the same as those of the first embodiment.

[0094] This embodiment provides the same effects as those of the second embodiment. That is, not only are the attraction surface side distance Z1 and the back surface side distance Z2 different from each other, but the increase rates of the attraction surface slope angle D1 and the back surface slope angle D2 are also different from each other, so the core block 20 becomes even more asymmetric with respect to the central axis O of the vibrator 2. This is more advantageous in suppressing the tilt of the attraction surface 21 of the core block 20.

[0095] Fourth Embodiment An ultrasonic horn 10 according to a fourth embodiment will be described. In the following description, the same components as those in the above embodiments will be designated by the same reference numerals, and detailed description thereof may be omitted. Figure 9 shows a front cross-sectional view of the ultrasonic horn according to the fourth embodiment.

[0096] In this embodiment, the core block 20 includes a rear surface step portion 27. In the core block 20, the rear surface step portion 27 is formed at a connection portion of the rear surface 22 to the front connecting block 40 (transmission portion) and at a connection portion of the rear surface 22 to the rear connecting block 60 (reflection portion). In the core block 20, the rear surface step portion 27 is formed at both ends (front end and rear end) of the rear surface 22 in the front-to-rear direction. The rear surface 22, the front connecting block 40, and the rear connecting block 60 are connected to each other via the rear surface step portion 27.

[0097] The rear step portion 27 is perpendicular to the central axis O of the vibrator 2. The rear step portion 27 forms a rear step angle D2', which is a rear side angle, at a right angle to the central axis O of the vibrator 2. The rear step angle D2' is the angle formed between the rear step portion 27 and the central axis O of the vibrator 2. The rear step angle D2' is 90°.

[0098] The suction surface slope angle D1, which is the angle between the suction surface slope portion 25 and the central axis O of the vibrator 2, is smaller than the rear surface step angle D2', which is the angle between the rear surface step portion 27 and the central axis O of the vibrator 2.

[0099] The other configurations are the same as those of the first embodiment.

[0100] This embodiment provides the same effects as those of the second embodiment. Furthermore, not only are the suction surface side distance Z1 and the back surface side distance Z2 different from each other, but the suction surface slope angle D1 and the back surface step angle D2′ are also significantly different from each other, so the core block 20 becomes even more asymmetric with respect to the central axis O of the vibrator 2. This is more advantageous in suppressing the tilt of the suction surface 21 of the core block 20.

[0101] Fifth Embodiment An ultrasonic horn 10 according to a fifth embodiment will be described. In the following description, the same components as those in the above embodiments will be designated by the same reference numerals, and detailed description thereof may be omitted. Figure 10 shows a front cross-sectional view of the ultrasonic horn 10 according to the fifth embodiment.

[0102] In this embodiment, the adsorption surface side distance Z1, which is the distance in the vertical direction between the adsorption surface 21 of the core block 20 and the central axis O of the vibrator 2, and the back surface side distance Z2, which is the distance in the vertical direction between the back surface 22 of the core block 20 and the central axis O of the vibrator 2, are equal to each other.

[0103] However, the suction surface side starting point P1 on the front connecting block 40 (transmission portion) side and the rear connecting block 60 (reflection portion) side of the suction surface slope portion 25 is located farther from the center C of the core block 20 in the front-to-rear direction than the back surface side starting point P2 on the front connecting block 40 (transmission portion) side and the rear connecting block 60 (reflection portion) side of the back surface slope portion 26. In other words, the distance between the suction surface side starting point P1 and the center C of the core block 20 is greater than the distance between the back surface side starting point P2 and the center C of the core block 20.

[0104] The other configurations are the same as those of the first embodiment.

[0105] This embodiment provides the same effects as the first embodiment. That is, instead of the suction surface side distance Z1 and the back surface side distance Z2 being equal to each other, the suction surface side starting point P1 and the back surface side starting point P2 have different positional relationships with respect to the center C of the core block 20 in the front-to-rear direction. The shape of the core block 20 is asymmetric with respect to the central axis O of the vibrator 2. This makes it possible to suppress waviness of the suction surface 21 of the core block 20 and also suppress tilting of the suction surface 21 of the core block 20.

[0106] Sixth Embodiment An ultrasonic horn 10 according to a sixth embodiment will be described. In the following description, the same components as those in the above embodiments will be designated by the same reference numerals, and detailed description thereof may be omitted. Figure 11 shows a front cross-sectional view of the ultrasonic horn according to the sixth embodiment.

[0107] In this embodiment, the core block 20 includes a rear surface step portion 27. In the core block 20, the rear surface step portion 27 is formed at a connection portion of the rear surface 22 to the front connecting block 40 (transmission portion) and at a connection portion of the rear surface 22 to the rear connecting block 60 (reflection portion).

[0108] The rear step portion 27 is perpendicular to the central axis O of the vibrator 2. The rear step portion 27 forms a rear step angle D2', which is a rear side angle, at a right angle to the central axis O of the vibrator 2. The rear step angle D2' is the angle formed between the rear step portion 27 and the central axis O of the vibrator 2. The rear step angle D2' is 90°.

[0109] The suction surface slope angle D1, which is the angle between the suction surface slope portion 25 and the central axis O of the vibrator 2, is smaller than the rear surface step angle D2', which is the angle between the rear surface step portion 27 and the central axis O of the vibrator 2.

[0110] The suction surface side starting point P1 on the front connecting block 40 (transmission section) side and the rear connecting block 60 (reflection section) side in the suction surface slope section 25 is located farther from the center C of the core block 20 in the front-to-back direction than the rear side starting point P2 on the front connecting block 40 (transmission section) side and the rear connecting block 60 (reflection section) side in the rear step section 27.

[0111] The other configurations are the same as those of the fifth embodiment.

[0112] This embodiment provides the same effects as the fifth embodiment. Furthermore, not only are the positional relationships between the suction surface-side starting point P1 and the rear surface-side starting point P2 different from each other relative to the center C of the core block 20 in the front-rear direction, but the suction surface slope angle D1 and the rear surface step angle D2' are also significantly different from each other, making the core block 20 even more asymmetric with respect to the central axis O of the vibrator 2. This is more advantageous in suppressing the tilt of the suction surface 21 of the core block 20.

[0113] <Other Embodiments> Although the present disclosure has been described above with reference to preferred embodiments, these descriptions are not limiting and, of course, various modifications, substitutions, and combinations are possible.

[0114] The suction surface side distance Z1 may be made larger than the rear surface side distance Z2, and the suction surface side starting point P1 may be positioned further away from the center C of the core block 20 in the front-rear direction than the rear surface side starting point P2.

[0115] The core block 20 may not be formed in a substantially rectangular parallelepiped shape, but may be formed in a polygonal prism shape or may be formed to have some roundness. In particular, the back surface 22 may be formed to have some roundness.

[0116] The transmission unit may be formed of a single member instead of the two members, the front side block 30 and the front connecting block 40. The reflection unit may be formed of a single member instead of the two members, the rear side block 50 and the rear connecting block 60.

[0117] The adsorption surface 21 may face in a direction other than downward, and the back surface 22 may face in a direction other than upward.

[0118] The object to be attracted is not limited to a semiconductor element.

[0119] The vibration is not necessarily limited to ultrasonic vibration, but may be vibration of a frequency lower than that of ultrasonic vibration.

[0120] The horn may be used alone or in combination with a bonding tool.

[0121] The present disclosure is applicable to horns and bonding tools and is therefore extremely useful and has high industrial applicability.

[0122] X: Forward / backward direction (first direction) Xa: Forward (one side of the first direction) Xb: Backward (the other side of the first direction) Y: Left / right direction (third direction) Z: Up / down direction (second direction) Za: Downward (one side of the second direction) Zb: Upward (the other side of the second direction) O: Central axis C: Central portion F: Ultrasonic vibration (vibration) W1: Substrate W2: Semiconductor element (object to be attracted) E1: Substrate-side electrode E2: Horn-side electrode B: Bump P1: Attracting surface-side starting point (starting point) P2: Rear surface-side starting point (starting point) Z1: Attracting surface-side distance (distance) Z2: Rear surface-side distance (distance) D1: Attracting surface slope angle (attracting surface-side angle) D2: Rear surface slope angle (rear surface-side angle) D2': Rear surface step angle (rear surface-side angle) 1: Bonding tool 10: Ultrasonic horn (horn) 2: Vibrator 3 Rib 4 Head 5 Stage 20 Core block (block portion) 21 Adsorption surface 22 Back surface 23 Passage 23a Large diameter portion 23b Small diameter portion 24 Adsorption hole (adsorption portion) 25 Adsorption surface slope portion 26 Back surface slope portion 27 Back surface step portion 30 Front side block (transmission portion) 31 Screw hole 40 Front connecting block (transmission portion) 50 Rear side block (reflecting portion) 60 Rear connecting block (reflecting portion)

Claims

1. A horn comprising: a block portion arranged in line with a vibrator in a first direction; a transmission portion arranged between the block portion and the vibrator in the first direction and transmitting vibrations from the vibrator to the block portion; and a reflection portion arranged on the opposite side of the block portion in the first direction from the transmission portion and reflecting the vibrations from the block portion, wherein the block portion includes: an adsorption surface facing one side of a second direction intersecting the first direction and having an adsorption portion for adsorbing an object to be adsorbed; and a back surface facing the other side of the second direction opposite to the adsorption surface, wherein the vibrator has a central axis extending in the first direction, and the block portion includes an adsorption surface slope portion inclined with respect to the central axis at a connection portion of the adsorption surface to the transmission portion and at a connection portion of the adsorption surface to the reflection portion, and the block portion is configured asymmetrically with respect to the central axis.

2. The horn according to claim 1, wherein the distance between said suction surface and said central axis is greater than the distance between said back surface and said central axis.

3. A horn as described in claim 1, wherein the block portion includes a back slope portion inclined with respect to the central axis or a back step portion perpendicular to the central axis at a connecting portion on the back surface to the transmission portion and a connecting portion on the back surface to the reflection portion, and a starting point of the suction surface slope portion on the transmission portion side and the reflection portion side is located farther from the block portion in the first direction than a starting point of the back slope portion or the back step portion on the transmission portion side and the reflection portion side.

4. A horn as described in any one of claims 1 to 3, wherein the block portion includes a rear slope portion inclined with respect to the central axis or a rear step portion perpendicular to the central axis at the connecting portion on the rear surface to the transmission portion and the connecting portion on the rear surface to the reflection portion, and an adsorption surface side angle which is the angle between the adsorption surface slope portion and the central axis is smaller than a rear side angle which is the angle between the rear slope portion or the rear step portion and the central axis.

5. The horn as set forth in claim 4, wherein the rate of increase of the suction surface side angle is smaller than the rate of increase of the back surface side angle.

6. A horn as described in any one of claims 1 to 3, wherein an adsorption surface side angle, which is the angle between the adsorption surface slope portion and the central axis, is 30° or more and 60° or less.

7. A bonding tool comprising: a horn as claimed in any one of claims 1 to 3; the vibrator; and a stage on which a substrate having a substrate-side electrode is placed, the horn-side electrode provided on a semiconductor element as the object to be attracted is aligned with the substrate-side electrode via a bump, and the vibrator applies the vibration to the horn, thereby bonding the horn-side electrode to the substrate-side electrode via the bump.

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