JP2012043944A - Mounting device of electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mounting device adapted to convey supersonic oscillation of an oscillator to a horn efficiently and reliably.SOLUTION: A mounting device includes: an oscillator 23 that performs supersonic oscillation; a horn 22 in which one end surface of the horn and one end surface of the oscillator are connected to each other so as to perform supersonic oscillation with the oscillator; a tool part that is provided in the horn and applies supersonic oscillation to a semiconductor chip with a load; an oscillation transmission member 19 in which one side surface is adhered tightly to the one end surface of the oscillator and the other side surface is adhered tightly to the one end surface of the horn when the oscillation transmission member is provided between the one end surface of the horn and the one end surface of the oscillator and connects the oscillator to the horn.

Description

  The present invention relates to an electronic component mounting apparatus that applies a load and sound wave vibration to an electronic component such as a semiconductor chip and mounts the electronic component on a substrate.

  For example, when a semiconductor chip with bumps, which is an electronic component, is mounted on a substrate such as a tape member made of polyimide or a metal lead frame, the semiconductor chip is mounted on the substrate by applying a pressing load and ultrasonic vibration. The method is known. That is, ultrasonic vibration is applied while pressing the semiconductor chip to the bonded surface of the substrate with a predetermined pressure, and the contact portion between the lead formed on the substrate and the bump of the semiconductor chip is bonded.

  Such mounting is performed using an ultrasonic mounting tool. The ultrasonic mounting tool has a horn. A vibrator is connected and fixed to one end of the horn in the longitudinal direction. An ultrasonic oscillator is electrically connected to this vibrator. This ultrasonic oscillator applies a high frequency voltage of 40 kHz, for example, to the vibrator. As a result, the vibrator is driven to vibrate ultrasonically, and the horn vibrates ultrasonically by the vibration wave. That is, the horn vibrates ultrasonically in the lateral direction, which is the longitudinal direction.

  A tool portion for sucking and holding the semiconductor chip is protruded from the lower surface of the middle portion of the horn. A suction hole is formed in the suction surface, which is the lower end surface of the tool portion, and the semiconductor chip is sucked and held on the suction surface of the tool portion by a suction force generated in the suction hole.

  Then, the ultrasonic mounting tool is driven in the descending direction with the semiconductor chip adsorbed and held on the tool portion, whereby the semiconductor chip is bonded to the substrate by ultrasonic vibration. Such prior art is disclosed in Patent Document 1.

  Conventionally, the vibrator and the horn constituting the ultrasonic mounting tool are integrally connected and fixed by, for example, screw connection. In addition, the length of the horn is unique to each ultrasonic mounting tool of each mounting device so that the antinode portion where the amplitude of the ultrasonic vibration transmitted to the horn is maximum is located at the position of the tool portion. It is set according to the characteristics. As a result, the semiconductor chip can be mounted on the substrate with the maximum energy of ultrasonic vibration.

Japanese Patent Laid-Open No. 2006-156813

  By the way, when the vibrator and the horn are screw-coupled, if the axis of the screw formed on the vibrator and the horn is slightly inclined, one end face of the joined vibrator and one end face of the horn Does not adhere to each other. In addition, even if the end surfaces of the vibrator and the horn are precisely polished, the end surfaces may not be in close contact due to the roughness of the end surfaces.

  When the vibrator is ultrasonically vibrated in a state where the vibrator and one end surface of the horn are not sufficiently adhered, that is, in a partial contact state, the ultrasonic vibration is not reliably transmitted from the vibrator to the horn. For this reason, the semiconductor chip may not be reliably mounted on the substrate.

  In addition, when the vibrator repeats ultrasonic vibration in a state where the vibrator and the one end surface of the horn are not in close contact with each other, the horn does not vibrate in conjunction with the ultrasonic vibration of the vibrator, and the one end face of the vibrator does not move. Since it vibrates in a state of repeated collision with the one end surface of the horn, the collision portion is heated to a high temperature to generate carbon, and the carbon is gradually accumulated, and the end surface of the vibrator and the horn The contact area is further reduced. As a result, the transmission efficiency of ultrasonic vibration from the vibrator to the horn is greatly reduced, which may cause a mounting failure of the semiconductor chip.

  Also, in order to position the belly part where the amplitude of ultrasonic vibration is maximized in the tool part provided on the horn according to the unique characteristics of the ultrasonic mounting tool, the horn is conventionally cut. It was done by adjusting the length. However, the workability of adjusting the length of the horn is not only very troublesome but also requires skill in the adjustment work.

  In the present invention, not only can the ultrasonic vibration of the vibrator be efficiently and reliably transmitted to the horn, the belly portion where the amplitude of the ultrasonic vibration transmitted to the horn is maximum is formed in the horn. An object of the present invention is to provide an electronic component mounting apparatus that can be easily positioned at a tool portion.

The present invention is a mounting apparatus for mounting an electronic component on a substrate while applying a load and ultrasonic vibration to the electronic component,
An ultrasonically vibrating vibrator,
A horn having one end face of the vibrator coupled to one end face thereof for ultrasonic vibration with the vibrator;
A tool part that is provided on the horn and applies ultrasonic vibration to the electronic component together with the load,
Provided between one end face of the horn and one end face of the vibrator, when the vibrator and the horn are connected, one side face is in close contact with one end face of the vibrator and the other side face is one end face of the horn. An electronic component mounting apparatus comprising: a vibration transmitting member that is in close contact with the electronic component.

  The vibration transmitting member is preferably formed of either a softer material or a harder material than the material forming the vibrator and the horn.

  The thickness of the vibration transmission member is set so that the antinode portion where the amplitude of the ultrasonic vibration transmitted from the vibrator to the horn is maximum is located in the tool portion provided in the horn. Is preferred.

  According to the present invention, a vibration transmission member is provided between one end surface of the horn and one end surface of the vibrator so that one side surface is in close contact with the one end surface of the vibrator and the other side surface is in close contact with the one end surface of the horn. Therefore, the one end surface of the vibrator and the one end surface of the horn can be brought into close contact with each other via the vibration transmitting member.

  Thereby, the ultrasonic vibration of the vibrator can be transmitted to the horn efficiently and surely, and by setting the thickness of the vibration transmitting member, the portion of the belly where the amplitude of the ultrasonic vibration is maximized can be It becomes possible to position on the tool part formed in this.

The front view of the mounting apparatus which shows one embodiment of this invention. The side view of the mounting apparatus shown in FIG. Sectional drawing which shows the state before a vibrator | oscillator and a horn are connected. Sectional drawing which shows the state with which the vibrator | oscillator and the horn were connected. The figure explaining the position of the antinode part of the ultrasonic vibration with respect to the tool part of a horn.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a side view of the mounting apparatus of the present invention, and FIG. 2 is a front view. As shown in FIG. 1, the mounting apparatus includes an apparatus main body 1. The apparatus main body 1 is provided with a Y guide body 2 along the Y direction, and the Y guide body 2 is provided with a Y movable body 3 indicated by an arrow so as to be driven in the Y direction.

  On the front end surface of the Y movable body 3, a pair of X guide bodies 4 spaced apart at a predetermined interval in the vertical direction are provided along the X direction. An X movable body 5 is provided on the X guide body 4 so as to be driven. The X movable body 5 has a side surface formed in an inverted L shape, and a receiving portion 6 that is movably engaged with the X guide body 4 is provided on the outer surface of the vertical wall.

  A pair of Z guide bodies 7 are provided on the inner surface of the vertical wall 5a of the X movable body 5 along the vertical direction so as to be spaced apart at a predetermined interval in the X direction. A Z movable body 8 is provided on the Z guide body 7 so as to be driven in the vertical direction indicated by an arrow Z. A plurality of, for example, four springs 11 are stretched between the upper surface of the Z movable body 8 and the lower surface of the horizontal wall 5b of the X movable body 5 to urge the Z movable body 8 in the upward direction. is doing.

  A cylinder 12 as a Z drive source is provided on the upper surface of the horizontal wall of the X movable body 5 with the axis line vertical. A pressing member 14 is provided at the tip of the rod 13 of the cylinder 12. The pressing member 14 is in contact with a roller 15 provided on the upper surface of the Z movable body 8 with the rotation axis line horizontal. Therefore, when the rod 13 of the cylinder 12 is biased in the protruding direction, the Z movable body 8 can be driven in the downward direction against the restoring force of the spring 11.

A θ drive source 16 is provided on the lower surface of the Z movable body 8. An ultrasonic mounting tool 21 is attached to the θ movable body 17 that is rotationally driven by the θ driving source 16. The ultrasonic mounting tool 21 has a prismatic horn 22 as shown in FIG. Similarly, a prismatic vibrator 23 is connected and fixed to one end in the longitudinal direction of the horn 22 via a vibration transmitting member 19 as will be described later.
Although not shown in detail, the vibrator 23 is configured by integrally coupling a plurality of piezoelectric elements in the axial direction.

  An oscillator (not shown) is electrically connected to the vibrator 23, and a high frequency voltage of 40 kHz, for example, is applied from this oscillator. Thereby, the vibrator 23 is ultrasonically vibrated, and the horn 22 is also ultrasonically vibrated together with the vibrator 23.

  A rectangular base portion 24 is provided on the lower surface of the central portion of the horn 22 in the longitudinal direction. On the lower surface of the base portion 24, the tool portion 25 protrudes over the entire length of the horn 22 in the width direction of the horn 22 where the amplitude of the ultrasonic vibration transmitted to the horn 22 is maximized. Is formed.

  One end of a suction hole (not shown) is formed in the lower end surface of the tool portion 25. The lower end surface of the tool portion 25 is adapted to be sucked and held by the suction force generated in the suction hole by the semiconductor chip C as an electronic component.

  A load receiving portion 27 having substantially the same planar shape as that of the base portion 24 is formed to protrude at the portion of the anti-vibration antinode S which is the central portion of the upper surface of the horn 22 corresponding to the tool portion 25. ing. The tool portion 25 and the load receiving portion 27 are integrally formed with the horn 22.

  On the upper surface of the load receiving portion 27, a strip-like bracket 28 having the same width dimension as the horn 22 and a length dimension shorter than that of the horn 22 is provided in contact with the lower surface of the central portion in the longitudinal direction. Both ends of the bracket 28 are connected and fixed to the nodes of the vibration wave where the amplitude of the ultrasonic vibration of the horn 22 is minimized by screws 29. The ultrasonic mounting tool 21 vibrates in the axial direction, that is, in the lateral direction.

  A portion between both end portions of the bracket 28 and a portion in contact with the load receiving portion 27 is formed as a low-rigidity portion 28 a that makes the rigidity of this portion lower than that of the other portions of the bracket 28. The low-rigidity portion 28 a is formed by a cavity 30 that penetrates the bracket 28 in the width direction. The hollow portion 30 has a long H shape along the longitudinal direction of the bracket 28, and the corner portion is formed in an R shape so as to avoid stress concentration.

  Therefore, in order to fix the bracket 28 to the horn 22 through the load receiving portion 27, when the screws 29 at both ends of the bracket 28 are tightened into the horn 22, the low-rigidity portion 28a in which the hollow portion 30 of the bracket 28 is formed. Is elastically deformed and curved. Therefore, even if both end portions of the bracket 28 are connected and fixed to the horn 22 with the screws 29, the center portion in the longitudinal direction of the bracket 28 and the load receiving portion 27 are maintained in a surface contact state.

  In the bracket 28, the upper surface of the portion that is in contact with the load receiving portion 27 is attached and fixed to the lower surface of the θ movable body 17. Therefore, the ultrasonic mounting tool 21 can be driven in the X, Y, Z, and θ directions.

  As shown in FIGS. 1 and 2, a stage 31 having a built-in heater 31 a is disposed below the ultrasonic mounting tool 21. Although not shown in detail, the stage 31 can be driven in the X, Y, and Z directions. A substrate 32 such as a polyimide tape-shaped member or a metal lead frame is supplied and mounted on the upper surface of the stage 31. The tool portion 25 of the ultrasonic mounting tool 21 is positioned and lowered with respect to the substrate 32.

Thereby, the semiconductor chip C held by the tool portion 25 is pressure-bonded, that is, mounted on the substrate 32 by the pressure applied by the Z movable body 8, the lateral vibration of the horn 22, and the heat of the heater 31 a provided on the stage 31. It has become so.
Although not shown, a heater may also be provided in the horn 22, and the mounting efficiency of the semiconductor chip C may be increased by the heat of the heater.

  FIG. 3 and FIG. 4 show the connection structure of the horn 22 and the vibrator 23 constituting the ultrasonic mounting tool 21. As shown in FIG. 3, on one end surface 22a of the horn 22 and one end surface 23a of the vibrator 23, screws 22b and 23b are formed to open to the central portions of the end surfaces 22a and 23a, respectively.

  As shown in FIG. 4, one end of a double-cut male screw 34 is screwed to the female screw 22b of the horn 22, and the other end of the male screw 34 is screwed to the female screw 23b of the vibrator 23. Is done. The vibration transmitting member 19 interposed between the one end surface 22a of the horn 22 and the one end surface 23a of the vibrator 23 is a rectangular plate member having a through hole 19a formed in the center, and is formed in the through hole 19a. The male screw 34 is inserted. Therefore, the horn 22 and the vibrator 23 are screw-coupled via the vibration transmission member 19.

  The horn 22 is made of steel such as high-speed steel or SKD11, and the vibrator 23 is made of metal such as iron, Ti alloy, or aluminum alloy. The vibration transmitting member 19 is made of a material softer than the metal material forming the horn 22 and the vibrator 23, for example, a metal material such as brass, or a resin material such as glass epoxy, peak material, or Rossna board (trade name). ing.

  Therefore, if the horn 22 and the vibrator 23 are screw-coupled by the external screw 34 and the vibration transmission member 19 is deformed by the hardness of the horn 22 and the vibrator 23, one side surface of the vibration transmission member 19 is obtained. Is in close contact with one end surface 22 a of the horn 22 and the other side surface is in close contact with the one end surface 23 a of the vibrator 23. That is, the one end surface 22 a of the horn 22 and the one end surface 23 a of the vibrator 23 are closely fixed via the vibration transmission member 19.

  If the one end surface 22a of the horn 22 and the one end surface 23a of the vibrator 23 are in close contact with each other, when the vibrator 23 is ultrasonically vibrated, the ultrasonic vibration is efficiently and reliably transmitted to the horn 22. .

  That is, when the vibrator 23 vibrates ultrasonically, the horn 22 integrally vibrates ultrasonically, so that the one end face 23a of the vibrator 23 repeatedly collides against the one end face 22a of the horn 22 to increase the temperature to a high temperature. It will not rise.

  This prevents carbon from being deposited between the end faces 22a of the horn 22 and the vibrator 23, so that the transmission efficiency of ultrasonic vibration from the vibrator 23 to the horn 22 is not reduced.

  By interposing the vibration transmission member 19 between the horn 22 and the vibrator 23, the total length of the ultrasonic mounting tool 21 can be adjusted by the thickness of the vibration transmission member 19. The thickness of the vibration transmitting member 19 is preferably equal to or less than a quarter of the wavelength of ultrasonic vibration.

  Accordingly, when the antinode portion where the amplitude of the ultrasonic vibration becomes maximum is displaced from the position of the tool portion 25 provided on the horn 22, the thickness of the vibration transmitting member 19 is changed to change the total length of the ultrasonic mounting tool 21. Is adjusted, the position of the antinode where the amplitude of the ultrasonic vibration becomes maximum can be matched with the tool portion 25.

  That is, when the thickness of the vibration transmission member 19 is t, the position of the antinode S where the amplitude of the ultrasonic vibration is maximum is shifted toward the vibrator 23 shown by S1 with respect to the tool portion 25 as shown in FIG. If the vibration transmitting member 19 is made thicker than t according to the amount of deviation, the position of the antinode where the amplitude is maximum can be adjusted from S1 to S.

  On the contrary, when the position of the antinode is shifted to the side opposite to the vibrator 23 as indicated by S2, the amplitude can be maximized if the thickness of the vibration transmitting member 19 is made smaller than t in accordance with the shift amount. Can be adjusted from S2 to S.

  Thus, according to the embodiment of the present invention, a material softer than the material forming the horn 22 and the vibrator 23 is provided between the one end face 22a of the horn 22 and the one end face 23a of the vibrator 23. The horn 22 and the vibrator 23 are screwed together with the formed vibration transmission member 19 interposed.

  Therefore, the one end surface 22a of the horn 22 and the one end surface 23a of the vibrator 23 are brought into close contact with each other via the vibration transmitting member 19, so that the ultrasonic vibration of the vibrator 23 can be reliably and efficiently transmitted to the horn 22. Therefore, the mounting efficiency of the semiconductor chip C on the substrate 32 can also be improved.

  The ultrasonic wave transmitted to the horn 22 by changing the overall length of the ultrasonic mounting tool 21 depending on the thickness of the vibration transmitting member 19 provided between the one end surface 22 a of the horn 22 and the one end surface 23 a of the vibrator 23. The position of the antinode S where the amplitude of vibration is maximized can be adjusted.

  Therefore, when the position of the ultrasonic vibration antinode S deviates from the tool portion 25 formed on the horn 22 due to the inherent characteristics of the ultrasonic mounting tool 21, the ultrasonic wave is adjusted by adjusting the thickness of the vibration transmitting member 19. The vibration belly S can be positioned at the tool portion 25.

  The horn 22 and the vibrator 23 are integrally coupled by a screw 34 via a vibration transmission member 19. Therefore, when the connection angle (rotation angle) with respect to the circumferential direction of the horn 22 and the vibrator 23 is limited, for example, the screwing amount of the external screw 34 with respect to the female screw 22b of the horn 22 is set to the thickness of the vibration transmitting member 19. Therefore, the connection angle of the vibrator 23 with respect to the horn 22 can be set to a desired angle.

  On the other hand, when the vibration transmission member 19 is formed of a heat insulating material such as resin, when the heater is attached to the horn 22 and the horn 22 is heated to 400 ° C., for example, the temperature of the vibrator 23 is The temperature can be lower than that of the horn 22, for example, 200 ° C., depending on the heat conductivity and thickness of the 19 materials. That is, the temperature rise of the entire ultrasonic mounting tool 21 can be changed depending on the material and thickness of the vibration transmitting member 19.

  Thus, when the temperature of the ultrasonic mounting tool 21 increases, the overall frequency decreases. For example, when the frequency of the ultrasonic mounting tool 21 is 40 KHZ, a difference of 2 KHZ may occur in the frequency due to a temperature rise. That is, the frequency of the ultrasonic mounting tool 21 changes due to the temperature rise.

  Therefore, the frequency of the ultrasonic mounting tool 21 can be adjusted by selecting the material and thickness of the vibration transmitting member 19 and changing the temperature rise of the entire ultrasonic mounting tool 21 by the heater provided on the horn 22. It becomes possible to do.

  That is, conventionally, the frequency is set by changing the total length of the ultrasonic mounting tool 21, but by using the vibration transmitting member 19, the ultrasonic wave is changed depending on the thickness and the heat insulation property of the material. The frequency of the mounting tool 21 can be changed.

  When the vibration transmission member 19 changes the frequency of the ultrasonic mounting tool 21, the position of the antinode of the ultrasonic vibration is displaced. Therefore, in this case, the thickness of the vibration transmission member 19 may be set so that the position of the antinode is located on the tool portion 25 of the horn 22.

  In the above embodiment, the vibration transmission member is made of a material softer than the material forming the horn and the vibrator. However, the vibration transmission member is made of a material harder than the material forming the horn and the vibrator. By using it, when the horn and the vibrator are screw-coupled, the end faces of the horn and the vibrator may be deformed and brought into close contact with the side surface of the vibration transmitting member.

  In addition, by using a material softer than the material that forms the horn and vibrator for the vibration transmission member, the vibration transmission member is deformed when the horn and the vibrator are screwed together. You may make it form with any material of the material which deform | transforms, or the material which elastically deforms.

  DESCRIPTION OF SYMBOLS 19 ... Vibration transmission member, 21 ... Ultrasonic mounting tool, 22 ... Horn, 22b ... Female screw, 23 ... Vibrator, 23b ... Female screw, 25 ... Tool part, 32 ... Substrate, 34 ... Male screw, C ... Semiconductor chip (Electronic components).

Claims (3)

A mounting device for mounting an electronic component on a substrate while applying a load and ultrasonic vibration to the electronic component,
An ultrasonically vibrating vibrator,
A horn having one end face of the vibrator coupled to one end face thereof for ultrasonic vibration with the vibrator;
A tool part that is provided on the horn and applies ultrasonic vibration to the electronic component together with the load,
Provided between one end face of the horn and one end face of the vibrator, when the vibrator and the horn are connected, one side face is in close contact with one end face of the vibrator and the other side face is one end face of the horn. An electronic component mounting apparatus comprising: a vibration transmitting member that is in close contact with the electronic component.   2. The electronic component mounting apparatus according to claim 1, wherein the vibration transmitting member is formed of either a softer material or a hard material than a material forming the vibrator and the horn.   The thickness of the vibration transmission member is set so that the antinode portion where the amplitude of the ultrasonic vibration transmitted from the vibrator to the horn is maximum is located in the tool portion provided in the horn. The electronic component mounting apparatus according to claim 1, wherein:

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