Mounting device and mounting method

Abstract

The present invention provides a mounting apparatus and mounting method that can suppress the generation of stress in bumps caused by temperature changes during bonding, thereby improving the connection quality between the substrate and the semiconductor chip. [Solution] The control device 30 acquires the position of the pressing unit stage 25 measured by the encoder 23a and the force applied to the pressing unit stage 25 measured by the load sensor 26. If the force applied by the load sensor 26 to pull the pressing unit stage 25 toward the substrate α is greater than or equal to a reference upper limit Fmax, or if the position change of the pressing unit stage 25 toward the substrate α relative to the reference position P2 is greater than or equal to a reference upper limit change, the control device 30 moves the pressing unit stage 25 with the pressing unit drive device 22 so that a force is applied to the semiconductor chip β in a direction that presses the semiconductor chip β toward the substrate α.

Description

Technical Field

[0001] The present invention relates to a mounting device and a mounting method for mounting a semiconductor chip on a substrate.

Background Art

[0002] A mounting device for mounting a semiconductor chip on a substrate is known. The mounting device heats the semiconductor chip while pressing it against the substrate on the stage. The semiconductor chip is connected to the substrate by melting of the bumps.

[0003] In such a mounting device, the bumps of the semiconductor chip are heated to the melting point while being pressed against the substrate. The semiconductor chip with the softened bumps is moved toward the substrate by the force applied by the mounting device. At this time, a plurality of bumps located between the substrate and the semiconductor chip body are greatly deformed as the gap between the substrate and the semiconductor chip body becomes smaller, and may contact adjacent bumps or adjacent wirings of the substrate.

[0004] Therefore, in order to suppress excessive deformation of the bumps, a mounting device that holds a semiconductor chip with softened bumps at a position a predetermined distance away from the substrate is known. The chip mounting device described in Patent Document 1 presses a semiconductor chip against an electrode of a substrate with a predetermined force while heating it with a tool supported by a tool holder. The chip mounting device has a tool holder position detection means for detecting the relative position of the tool holder with respect to the tool holder support means that supports the tool holder. When the relative position of the tool holder detected by the tool holder position detection means reaches a fourth position, the chip mounting device determines that the bumps have melted and raises the tool holder support means to the first position. Thereby, it is possible to prevent the occurrence of bonding failure due to contact between adjacent bumps and to make the interval between the semiconductor chip and the substrate after bonding constant.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Patent No. 5014151 [Overview of the project] [Problems that the invention aims to solve]

[0006] The chip mounting apparatus described in Patent Document 1 suppresses bonding defects between the substrate and the semiconductor chip by maintaining a constant distance between the substrate and the semiconductor chip. However, the bumps shrink in volume as solidification progresses, generating a force that pulls the semiconductor chip body towards the substrate. On the other hand, the tool holder and tool that hold the semiconductor chip shrink in volume as the temperature decreases, generating a force that pulls the semiconductor chip away from the substrate. Therefore, due to the shrinkage of the bumps and the shrinkage of the tool holder, etc., variations in bonding strength and bonding state between the substrate and the semiconductor chip may occur, resulting in a decrease in bonding quality.

[0007] The object of the present invention is to provide a mounting apparatus and mounting method that suppress the generation of tensile stress in bumps due to temperature changes during bonding, thereby improving the connection quality between the substrate and the semiconductor chip. [Means for solving the problem]

[0008] The inventors of the present invention investigated the configuration of a mounting apparatus and a semiconductor chip mounting method that suppress the generation of stress in bumps due to temperature changes during bonding and improve the connection quality between the substrate and the semiconductor chip. As a result of diligent investigation, the inventors of the present invention came up with the following configuration.

[0009] An embodiment of the present invention provides a mounting apparatus comprising: a stage on which a substrate on which a semiconductor chip is mounted is placed; a pressing unit arranged opposite to the stage, which moves to an arbitrary position toward the stage and applies an arbitrary force to the substrate and the semiconductor chip; a heating unit supported by the pressing unit and heating the semiconductor chip; a holding unit supported by the heating unit and holding the semiconductor chip; and a control unit that controls the pressing unit and the heating unit. The mounting apparatus presses the semiconductor chip held by the holding unit against the substrate on the stage, heats the semiconductor chip with the heating unit to melt the bumps, and bonds the semiconductor chip to the substrate.

[0010] The mounting apparatus includes a position measuring unit for measuring the position of the holding portion and a force measuring unit for measuring the force applied to the holding portion. The control unit acquires the position of the holding portion measured by the position measuring unit. The control unit acquires the force applied to the holding portion measured by the force measuring unit. When the control unit determines that the bumps on the semiconductor chip have melted based on at least one of the acquired position of the holding portion and the force applied to the holding portion, while the pressing portion is pressing the semiconductor chip against the substrate and the heating portion is heating the semiconductor chip, the pressing portion holds the holding portion at a reference position for mounting the semiconductor chips on the substrate at predetermined intervals and stops heating the semiconductor chip by the heating portion. Furthermore, if the force measured by the force measuring unit pulling the holding part towards the substrate is greater than or equal to a reference upper limit, or if the position change of the holding part in the thickness direction of the substrate relative to the reference position is greater than or equal to a reference upper limit change, the control unit moves the holding part with the pressing unit so that a force is applied to the semiconductor chip in the direction of pressing the semiconductor chip against the substrate. Also, if the force measured by the force measuring unit pulling the holding part towards the substrate is less than a reference lower limit, or if the position change of the holding part in the thickness direction of the substrate relative to the reference position is less than a reference lower limit change, the control unit stops the movement of the holding part by the pressing unit and maintains the stopped position of the holding part.

[0011] Furthermore, the semiconductor chip mounting method according to an embodiment of the present invention is a semiconductor chip mounting method that involves pressing and heating the semiconductor chip to melt the bumps on the semiconductor chip and mounting it to a substrate. The semiconductor chip mounting method includes a bump heating step, a bump melting determination step, a bump solidification step, and a gap adjustment step. In the bump heating step, the semiconductor chip is pressed against the substrate with a predetermined force and heated. In the bump melting determination step, it is determined that the bumps have melted when the semiconductor chip pressed against the substrate moves toward the substrate by a melting determination distance or more. In the bump solidification step, if it is determined in the bump melting determination step that the bumps have melted, the semiconductor chip is held at a reference position for mounting the semiconductor chips on the substrate at a predetermined interval and the heating of the semiconductor chip is stopped. In the gap adjustment step, if the force pulling the semiconductor chip towards the substrate is greater than or equal to a reference upper limit in the solidification step, or if the positional change of the semiconductor chip portion in the thickness direction of the substrate relative to the reference position is greater than or equal to a reference upper limit change, then a force is applied to press the semiconductor chip against the substrate. Furthermore, in the bump solidification step, if the force pulling the semiconductor chip towards the substrate is less than a reference lower limit, or if the positional change of the semiconductor chip in the thickness direction of the substrate relative to the reference position is less than a reference lower limit change, then the movement of the semiconductor chip is stopped and the stopped position of the semiconductor chip is maintained.

[0012] In the above configuration, when the mounting apparatus and the semiconductor chip mounting method determine that the bumps of the semiconductor chip have melted (bump melting determination step), the holding part holds the semiconductor chip at the reference position and stops heating the semiconductor chip by the heating part (bump solidification step). The bumps begin to solidify at the reference position. At this time, the bumps shrink as solidification progresses. Therefore, a force is generated in the bumps that pulls the semiconductor chip body toward the substrate. On the other hand, the holding part, which had expanded due to heating, shrinks at the reference position as the temperature decreases. Therefore, a force is generated in the holding part that pulls the semiconductor chip toward the substrate. As a result, the semiconductor chip moves toward the substrate from the reference position. Furthermore, the bumps are subjected to both a tensile force that pulls the semiconductor chip toward the substrate and a tensile force caused by the movement of the semiconductor chip toward the substrate.

[0013] If the tensile force of the bump measured by the force measuring unit exceeds a standard upper limit, the mounting apparatus moves the holding unit toward the substrate until the tensile force of the bump falls below a standard lower limit, thereby applying a force that presses the semiconductor chip toward the substrate. In other words, the holding unit is moved to apply a force to the bump that counteracts the tensile force generated on the bump (gap adjustment process). Similarly, if the change in the semiconductor chip measured by the position measuring unit exceeds a standard upper limit change, the mounting apparatus moves the holding unit until the change in the semiconductor chip falls below a standard lower limit change, thereby applying a force that presses the semiconductor chip toward the substrate (gap adjustment process). The gap between the semiconductor chip and the substrate, which has increased due to the contraction of the holding unit, decreases due to the movement of the semiconductor chip. Furthermore, the tensile force of the bump, which was generated by the contraction of the holding unit and the contraction of the bump, is reduced by the movement of the semiconductor chip toward the thickness direction of the substrate. In this way, the mounting apparatus can adjust the position of the semiconductor chip relative to the substrate if the position of the semiconductor chip changes due to the contraction of the holding part as the temperature decreases, using the tensile force as an indicator. Furthermore, if stress is generated in the bumps due to the contraction of the holding part and the bumps as the temperature decreases, the mounting apparatus can reduce the stress generated in the bumps using the tensile force as an indicator. This improves the connection quality between the substrate and the semiconductor chip.

[0014] From another perspective, the mounting apparatus of the present invention preferably includes the following configuration. The control unit determines that the bumps of the semiconductor chip have melted when, in a state in which the semiconductor chip is pressed against the substrate by the pressing unit and the semiconductor chip is heated by the heating unit, the holding unit moves toward the substrate beyond the melting determination distance, or when the force measured by the force measuring unit in the direction of pressing the holding unit against the substrate decreases to or below the melting determination force.

[0015] In the above configuration, the mounting device determines the melting of the bumps, which are difficult to visually confirm with a camera or the like, by at least one of the amount of movement of the holding part or the force applied to the holding part. This makes it possible to indirectly determine the melting of the bumps. Furthermore, when it is determined that the bumps have melted, the semiconductor chip is held at the reference position, which suppresses short circuits between adjacent bumps and between adjacent wiring. This suppresses the generation of stress in the bumps due to temperature changes during bonding, and improves the connection quality between the substrate and the semiconductor chip.

[0016] From another perspective, the mounting apparatus of the present invention preferably includes the following configuration. The control unit controls the pressing unit by torque control, which controls the force applied to the holding unit as a reference, until it determines that the bumps of the semiconductor chip have melted. When the control unit determines that the bumps of the semiconductor chip have melted, it switches to position control, which controls the pressing unit as a reference, based on the position of the holding unit. If the force in the direction of pulling the holding unit towards the substrate is greater than or equal to a reference upper limit, or if the position change of the holding unit in the thickness direction of the substrate relative to the reference position is greater than or equal to a reference upper limit change, the control unit controls the pressing unit by torque control. If the force in the direction of pulling the holding unit towards the substrate, as measured by the force measuring unit, is less than a reference lower limit, or if the position change of the holding unit in the thickness direction of the substrate relative to the reference position is less than a reference lower limit change, the control unit controls the pressing unit by position control.

[0017] In the above configuration, the mounting device presses the semiconductor chip against the substrate with a predetermined force by torque control until the bump melts. In other words, the mounting device maintains the state in which a predetermined force is applied without moving the holding part to the reference position by position control when the bump is not melted. Therefore, in the solidified bump that can support the semiconductor chip body, the stress generated by pressing the semiconductor chip against the substrate with torque control that has a limited output force is smaller than the stress generated by moving the semiconductor chip to the reference position by position control that has no limit on the output force. Furthermore, when the bump of the semiconductor chip melts, the mounting device holds the holding part at the reference position by position control. In other words, in the melted bump, the mounting device moves the semiconductor chip to the reference position without moving it to a movable position by torque control that does not have a defined holding position. Therefore, in the melted bump that cannot support the semiconductor chip body, short circuits of the bump are suppressed by holding the holding part at the reference position.

[0018] Furthermore, when the temperature of the holding portion and the bump decreases and the holding portion and the bump begin to shrink, the mounting apparatus moves the pressing portion toward the substrate by torque control. In other words, when the semiconductor chip body is being attracted to the substrate by the solidified bump, the mounting apparatus does not hold the holding portion in the reference position by position control. Therefore, the force generated in the bump by solidification that attracts the semiconductor chip body to the substrate is suppressed by torque control that applies a force to the semiconductor chip pressing it against the substrate. This suppresses the generation of stress in the bump due to temperature changes during bonding and improves the connection quality between the substrate and the semiconductor chip.

[0019] From another perspective, the mounting apparatus of the present invention preferably includes the following configuration. The control unit stops the movement of the pressing part and holds the stopped position of the pressing part after a predetermined time has elapsed since starting the control of the pressing part by torque control when the force in the direction of pulling the holding part toward the substrate is greater than or equal to a reference upper limit, or when the position change of the holding part toward the substrate thickness direction relative to the reference position is greater than or equal to a reference upper limit change.

[0020] In the above configuration, the mounting device maintains the position of the holding part after a predetermined time has elapsed since the start of mounting the semiconductor chip, and terminates the mounting control of the semiconductor chip. Therefore, the mounting device does not repeatedly apply force to the semiconductor chip to the bump more than a certain number of times. This suppresses the generation of stress in the bump due to temperature changes during bonding, and improves the connection quality between the substrate and the semiconductor chip.

[0021] From another perspective, the mounting device of the present invention preferably includes the following configuration: The pressing unit includes a servo motor and a servo amplifier that supplies current to the servo motor based on a control signal from the control unit. The position measuring unit includes an encoder that detects the rotation angle of the servo motor. The servo amplifier supplies current to the servo motor based on a control signal from the control unit, and when it obtains a feedback signal from the servo motor, it supplies current to the servo motor based on the difference between the control signal and the feedback signal.

[0022] In the above configuration, the control device transmits a control signal to the servo amplifier that constitutes the pressing unit. The servo amplifier that has acquired the control signal from the control device moves the holding unit to the commanded position by the servo motor while acquiring a feedback signal of the rotation angle of the servo motor from the encoder. At this time, the mounting device processes the feedback signal acquired by the servo amplifier without transmitting it to the control device. Therefore, since the pressing unit controls the servo motor by the servo amplifier, control can be performed at a higher speed than when the control unit outputs a control signal to the servo amplifier based on the feedback signal. As a result, it is possible to suppress the generation of stress generated in the bumps due to temperature changes during bonding, and to improve the connection quality between the substrate and the semiconductor chip.

[0023] The technical terms used in this specification are used for the purpose of defining only specific embodiments, and are not intended to limit the invention by said technical terms.

[0024] In this specification, the use of "including", "comprising", "having" and their variants identifies the presence of the described features, steps, operations, elements, components, and / or their equivalents, but can include one or more of steps, operations, elements, components, and / or groups thereof.

[0025] In this specification, "attached", "connected", "coupled" and / or their equivalents are used in a broad sense and include both "direct and indirect" attachment, connection and coupling. Further, "connected" and "coupled" are not limited to physical or mechanical connection or coupling, and can include direct or indirect electrical connection or coupling.

[0026] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Advantages of the Invention

[0027] According to an embodiment of the present invention, the mounting device and the method for mounting a semiconductor chip can suppress the generation of tensile stress generated in the bumps due to temperature changes during bonding, and improve the connection quality between the substrate and the semiconductor chip.

Brief Description of the Drawings

[0028] [Figure 1] FIG. 1 is an overall configuration diagram of a mounting device in an embodiment of the present invention. [Figure 2] FIG. 2 is a control block diagram of the mounting device in an embodiment of the present invention. [Figure 3] FIG. 3 is a process diagram of a method for mounting a semiconductor chip on a substrate by the mounting device of the present invention. [Figure 4] FIG. 4 is a schematic diagram showing a bump heating process in the mounting device in an embodiment of the present invention. [Figure 5] FIG. 5 is a schematic diagram showing a bump melting determination process in the mounting device in an embodiment of the present invention. [Figure 6] FIG. 6 is a schematic diagram showing a bump solidification process in the mounting device in an embodiment of the present invention. [Figure 7] FIG. 7 is a schematic diagram showing the state of the force applied to the holding part in the bump solidification process in the mounting device in an embodiment of the present invention. [Figure 8] FIG. 8 is a schematic diagram showing a gap adjustment process in the mounting device in an embodiment of the present invention. [Figure 9] FIG. 9 is a diagram showing a graph representing the position of the holding part, the force applied to the holding part, and the temperature of the holding part when mounting a semiconductor chip on a substrate by the mounting device in an embodiment of the present invention. [Figure 10]Figure 10 is a graph showing the position of the holding part, the force applied to the holding part, and the temperature of the holding part when mounting a semiconductor chip on a substrate in another mounting method according to an embodiment of the present invention. [Modes for carrying out the invention]

[0029] The mounting device according to the present invention will be described below with reference to the drawings. In each figure, the same parts are denoted by the same reference numerals, and the description of the same parts will not be repeated. The dimensions of the components in each figure do not faithfully represent the actual dimensions of the components or the dimensional ratios of each component. In the following description of embodiments of the present invention, the X direction and Y direction are assumed to be directions on the horizontal plane. The Y direction is perpendicular to the X direction. The Z direction is perpendicular to both the X and Y directions. In this embodiment, the Z direction is defined as the vertical direction. However, this definition of direction is not intended to limit the orientation of the positioning device when it is used in each embodiment.

[0030] <Configuration of the mounting device> Using Figures 1 and 2, we will describe an embodiment of the mounting apparatus according to the present invention, namely mounting apparatus 1. Figure 1 is an overall configuration diagram of mounting apparatus 1 in an embodiment of the present invention. Figure 2 is a control block diagram of mounting apparatus 1.

[0031] As shown in Figures 1 and 2, the mounting device 1 mounts a semiconductor chip β onto a substrate α. The mounting device 1 is installed in a semiconductor manufacturing apparatus (not shown). The mounting device 1 includes a stage unit 10, a first heater 13, a first attachment 14, a pickup unit 20, a pressing unit 21, an encoder 23a which is a position measuring unit, a load sensor 26 which is a force measuring unit, an air gyro 27, a second heater 28, a second attachment 29, and a control device 30.

[0032] In this specification, substrate α refers to a substrate made of materials such as silicon, ceramics, or resin, on which a semiconductor chip β is mounted, and on which a wiring substrate is patterned. Substrate α has wiring made of conductors. The wiring on substrate α is connected by welding bumps γ, which are protruding solder points on the semiconductor chip β. Substrate α includes the semiconductor chip β. In other words, substrate α includes a semiconductor chip on which the semiconductor chip β is mounted.

[0033] As shown in Figure 1, the stage unit 10 positions the substrate α at any position on the XY plane. The stage unit 10 includes a stage drive unit 11 and a stage 12 on which the substrate α is placed. The stage unit 10 is supported by a frame (not shown). The stage unit 10 is configured so that the stage 12 can be moved to any position on the XY plane by the stage drive unit 11. The stage unit 10 supports a first heater 13 and a first attachment 14.

[0034] The heating element, the first heater 13, heats the substrate α via the first attachment 14. The first heater 13 is, for example, a pulse heater having a ceramic housing. The first heater 13 also includes laser heating type heaters that heat using a laser. The first heater 13 is configured to rapidly raise the temperature to a preset temperature. The first heater 13 is fixed to the stage unit 10. The first heater 13 is positioned with its heating surface facing the Z direction. The first heater 13 is configured to be movable integrally with the stage unit 10.

[0035] The first attachment 14 holds the substrate α. The first attachment 14 is made of, for example, a rectangular parallelepiped made of metal. The first attachment 14 is fixed to the heating surface of the first heater 13 in a detachable manner. The first attachment 14 has a plurality of suction holes (not shown) on the surface that holds the substrate α. The first attachment 14 is configured to hold the substrate α by adsorption using the suction force generated in the suction holes. The first attachment 14 is configured to be movable together with the first heater 13 by the stage unit 10. The first attachment 14 is also heated by the first heater 13.

[0036] The pickup unit 20 positions the semiconductor chip β at any position on the XY plane. The pickup unit 20 is supported by a frame (not shown). The pickup unit 20 is configured to be movable to any position on the XY plane. The pickup unit 20 is equipped with a camera 20a that measures the positions of the substrate α and the semiconductor chip β. The pickup unit 20 supports the pressing unit 21. In other words, the pickup unit 20 moves the pressing unit 21 to any position on the XY plane.

[0037] The pressing unit 21, which is the pressing part, is a unit that moves the semiconductor chip β in the Z direction and applies a predetermined force to the semiconductor chip β. The pressing unit 21 has a pressing unit drive device 22 and a pressing unit stage 25. The pressing unit 21 is fixed to the pickup unit 20. The pressing unit 21 is configured to move integrally with the pickup unit 20.

[0038] The pressing unit drive device 22 moves the pressing unit stage 25 to any position in the Z direction. The pressing unit drive device 22 also applies a predetermined force in the Z direction to the pressing unit stage 25. The pressing unit drive device 22 includes, for example, a ball screw (not shown), a servo motor 23 (see Figure 2), and a servo amplifier 24 (see Figure 2). The servo motor 23 has an encoder 23a (see Figure 2), which is a position measuring unit. The ball screw is connected to the pressing unit stage 25. The servo motor 23 is connected to the ball screw. The servo amplifier 24 is connected to the servo motor 23. The servo amplifier 24 is connected to the control device 30.

[0039] The encoder 23a, which is the position measurement unit, detects the rotation angle of the servo motor 23. The encoder 23a outputs the rotation angle of the servo motor 23 as a feedback signal to the servo amplifier 24 in real time. In other words, the encoder 23a measures the amount of movement of the pressing unit stage 25 based on the rotation angle of the servo motor 23.

[0040] The servo motor 23 drives the ball screw with current supplied from the servo amplifier 24 to move the pressing unit stage 25. The servo amplifier 24 supplies current to the servo motor 23 based on a control signal from the control device 30. In the case of position control that controls based on the position of the pressing unit stage 25 in the Z direction, the control device 30 transmits a position control signal to the servo amplifier 24. The servo amplifier 24 supplies current to the servo motor 23 based on the position control signal obtained from the control device 30. Furthermore, when the servo amplifier 24 obtains the feedback signal from the encoder 23a, it supplies current to the servo motor 23 based on the difference between the position control signal and the feedback signal. In other words, the control device 30 transmits a position control signal to the servo amplifier 24 regarding the target position of the servo motor 23. On the other hand, the control device 30 does not transmit a position control signal for the servo motor 23 per unit time to the servo amplifier 24.

[0041] In the case of torque control, where the control device 30 controls based on the torque output to the pressing unit stage 25, it transmits a torque control signal to the servo amplifier 24. The servo amplifier 24 supplies current to the servo motor 23 based on the torque control signal obtained from the control device 30. Furthermore, when the servo amplifier 24 obtains a load feedback signal from the load sensor 26, it supplies current to the servo motor 23 based on the difference between the torque control signal and the load feedback signal. In other words, the control device 30 transmits a torque control signal related to the target torque of the servo motor 23 to the servo amplifier 24. On the other hand, the control device 30 does not transmit a torque control signal for the servo motor 23 per unit time to the servo amplifier 24.

[0042] The pressing unit stage 25, which is the holding part, is moved in the Z direction by the pressing unit drive device 22. The pressing unit stage 25 supports the second attachment 29 that holds the semiconductor chip β. The position of the pressing unit stage 25 in the Z direction is measured by the encoder 23a. Therefore, the pressing unit stage 25 is a reference member for the Z direction position of the semiconductor chip β.

[0043] The load sensor 26, which is the force measuring unit, measures the force applied to the semiconductor chip β. The load sensor 26 is composed of force-measuring sensors such as pressure sensors, load cells, and strain gauges. At least one load sensor 26 is provided between the pressing unit stage 25 and the air gyro 27. In this embodiment, three load sensors 26 are provided on the pressing unit stage 25. The load sensor 26 measures the force in the Z direction applied to the semiconductor chip β by the pressing unit drive device 22. The load sensor 26 also measures the force in the Z direction applied to the semiconductor chip β due to the contraction of the bump γ and the second attachment 29 of the semiconductor chip β. The load sensor 26 is configured to be movable integrally with the pressing unit stage 25.

[0044] The air gyro 27 adjusts the parallelism with respect to the object. The air gyro 27 has a spherical bearing section and a stage section. The air gyro 27 adjusts the tilt error between the contact surface of the object and the stage section by bringing the stage section into contact with the object. One end of the air gyro 27 is fixed to the pressing unit stage 25 via a load sensor 26. A second heater 28 is fixed to the other end of the air gyro 27. The air gyro 27 is configured to move integrally with the pressing unit stage 25.

[0045] The heating element, the second heater 28, heats the semiconductor chip β via the second attachment 29. The second heater 28 is, for example, a pulse heater having a ceramic housing. The second heater 28 also includes laser heating type heaters that heat using a laser. The second heater 28 is configured to rapidly raise the temperature to a preset temperature. The second heater 28 is fixed to the air gyro 27. The second heater 28 is positioned with its heating surface facing the Z direction. The second heater 28 is configured to move integrally with the pressing unit stage 25.

[0046] The second attachment 29, which is the holding part, holds the semiconductor chip β. The second attachment 29 is made of, for example, an inorganic material such as ceramics or glass, or a rectangular parallelepiped made of metal. The second attachment 29 is fixed to the mounting surface of the pressing unit 21 in a detachable manner. The second attachment 29 has suction holes (not shown) on the holding surface that holds the semiconductor chip β. The second attachment 29 holds the semiconductor chip β by suction force generated in the suction holes. The second attachment 29 is configured to be movable integrally with the pressing unit stage 25.

[0047] As shown in Figure 2, the control unit, the control device 30, controls the stage drive unit 11, the first heater 13, the pickup unit 20, the camera 20a, the servo amplifier 24, the second heater 28, and a suction pump (not shown). The control device 30 acquires position information from the encoder 23a. The control device 30 also acquires load information from the load sensor 26. The control device 30 is essentially a CPU, ROM, RAM, HDD, etc., connected by a bus. Alternatively, the control device 30 may be configured as a single-chip LSI or the like. The control device 30 stores various programs and data to control the operation of the stage drive unit 11, the first heater 13, the pickup unit 20, the camera 20a, the servo amplifier 24, the encoder 23a, the load sensor 26, the second heater 28, and a suction pump (not shown).

[0048] The control device 30 is electrically connected to the X-direction actuator and Y-direction actuator of the stage drive unit 11. The control device 30 is electrically connected to the X-direction actuator and Y-direction actuator of the pickup unit drive unit 21a. The control device 30 is electrically connected to the servo amplifier 24. The control device 30 is electrically connected to the first heater 13 and the second heater 28.

[0049] Furthermore, the control device 30 is electrically connected to the camera 20a. The control device 30 is electrically connected to the X-direction scale and Y-direction scale included in the stage drive device 11 and the pickup unit 20. The control device 30 is electrically connected to the encoder 23a and the three load sensors 26. The control device 30 uses the measurement value of the encoder 23a as the Z-direction position of the pressing unit stage 25. The control device 30 uses the average of the measurement values ​​of the three load sensors 26 as the force applied to the semiconductor chip β.

[0050] The control device 30 is configured to output a position control signal to the stage drive device 11 for positioning the first attachment 14 (see Figure 1), which is mounted on the stage unit 10, at the target position.

[0051] The control device 30 is configured to output a position control signal to the pickup unit 20 for positioning the second attachment 29, which is mounted on the pressing unit 21, to the target position. The control device 30 is configured to output a position control signal to the pressing unit drive device 22 for positioning the pressing unit stage 25 to the target position and a torque control signal for outputting a target torque. The control device 30 is also configured to output a temperature control signal to the first heater 13 and the second heater 28 for raising their temperature to a predetermined level. The control device 30 is configured to output a control signal to the camera 20a for imaging the substrate α and the semiconductor chip β. The control device 30 is also configured to output a suction control signal to a suction pump (not shown).

[0052] The control device 30 can acquire the X and Y coordinates of the substrate α and semiconductor chip β using the camera 20a. The control device 30 can acquire the X and Y coordinates of the first attachment 14 and the second attachment 29 using the X and Y direction scales. The control device 30 can acquire the Z coordinate of the second attachment 29 using the encoder 23a.

[0053] In the mounting apparatus 1 configured in this way, when a substrate α is placed on the first attachment 14 of the stage unit 10 from an external transport device, the mounting apparatus 1 holds the substrate α by suction force. The mounting apparatus 1 holds the semiconductor chip β by suction force using the second attachment 29 of the pickup unit 20. The mounting apparatus 1 acquires the position of the substrate α using the camera 20a and adjusts the position of the substrate α in the X and Y directions using the stage drive unit 11. Furthermore, the mounting apparatus 1 adjusts the position of the semiconductor chip β in the X and Y directions using the pickup unit drive unit 21a. The mounting apparatus 1 adjusts the position of the semiconductor chip β in the Z direction using the pressing unit drive unit 22 and places the semiconductor chip β at a predetermined position on the substrate α.

[0054] The mounting apparatus 1 uses a pressing unit drive device 22 to press the semiconductor chip β, which is positioned at a predetermined location on the substrate α, toward the substrate α. Simultaneously, the mounting apparatus 1 heats the substrate α via the first attachment 14 using the first heater 13. The heat transferred to the substrate α via the first attachment 14 melts the bump γ (see Figure 4) of the semiconductor chip β. In this way, the mounting apparatus 1 connects the semiconductor chip β to the predetermined location on the substrate α.

[0055] <Implementation Method> Next, a mounting method for mounting a semiconductor chip β onto a substrate α using a mounting apparatus 1 will be explained using Figures 1 to 9. Figure 3 is a process diagram of the mounting method for mounting a semiconductor chip β onto a substrate α using a mounting apparatus 1. Figure 4 is a schematic diagram showing the bump heating process S1 in the mounting apparatus 1. Figure 5 is a schematic diagram showing the bump melting determination process S2 in the mounting apparatus 1. Figure 6 is a schematic diagram showing the bump solidification process S3 in the mounting apparatus 1. Figure 7 is a schematic diagram showing the state of the force applied to the pressing unit stage 25 in the bump solidification process S3 in the mounting apparatus 1. Figure 8 is a schematic diagram showing the gap adjustment process S4 in the mounting apparatus 1. Figure 9 is a graph showing the position of the pressing unit stage 25, the force applied to the pressing unit stage 25, and the temperature of the pressing unit stage 25 when mounting a semiconductor chip β onto a substrate α using a mounting apparatus 1.

[0056] In this embodiment, the mounting apparatus 1 holds the substrate α by suction on the first attachment 14 and the semiconductor chip β by suction on the second attachment 29. The mounting apparatus 1 also positions the semiconductor chip β relative to the substrate α using a pickup unit 20. Furthermore, the mounting apparatus 1 moves the semiconductor chip β in the Z direction while switching from position control to torque control at a position where the substrate α and the semiconductor chip β are not in contact.

[0057] As shown in Figure 3, the semiconductor chip β mounting method includes a bump heating step S1, a bump dissolution determination step S2, a bump solidification step S3, and a gap adjustment step S4. The mounting apparatus 1 proceeds through the steps in the following order: bump heating step S1, bump dissolution determination step S2, bump solidification step S3, and gap adjustment step S4.

[0058] As shown in Figures 1, 2, 3, 4, and 9, the bump heating process S1 is a process of pressing and heating a semiconductor chip β onto a substrate α with a predetermined force (see Figures 3 and 9). In the bump heating process S1, the mounting apparatus 1 holds the substrate α with a first attachment 14 and the semiconductor chip β with a second attachment 29 (see Figure 4). The control device 30 (see Figure 2) switches the control of the servo motor 23 of the pressing unit drive device 22 to torque control that outputs a constant torque (see Figure 9). The control device 30 transmits a torque control signal to the servo amplifier 24 to move the pressing unit stage 25 in the Z direction with a predetermined force (see Figure 2). The servo amplifier 24 supplies power to the servo motor 23 to output a constant torque. The servo motor 23 moves in the Z direction so as to apply a constant force to the pressing unit stage 25. Thus, the mounting apparatus 1 presses the semiconductor chip β onto the substrate α at a predetermined position with a predetermined force using the pressing unit 21 (see Figure 4). Furthermore, the control device 30 transmits control signals to the first heater 13 and the second heater 28 to cause them to heat up to a predetermined temperature. As a result, the mounting device 1 presses the semiconductor chip β onto the substrate α with a predetermined force and heats it to a predetermined temperature.

[0059] As shown in Figures 1, 2, 3, 5, and 9, the bump dissolution determination step S2 is a step in determining whether or not the bumps on the semiconductor chip β have dissolved. In the bump dissolution determination step S2, the control device 30 acquires a signal from the encoder 23a indicating the position of the pressing unit stage 25 in the Z direction (see Figure 2). The control device 30 calculates the amount of movement of the pressing unit stage 25. The semiconductor chip β, which is pressed against the substrate α with a predetermined force by the pressing unit 21, moves toward the substrate α due to the dissolution of the bump γ. Therefore, the control device 30 determines that the bump γ has dissolved if the amount of movement of the pressing unit stage 25 in the Z direction from the contact position P1 where the semiconductor chip β is in contact with the substrate α is greater than or equal to the dissolution determination distance L0 (see Figures 5 and 9).

[0060] As shown in Figures 1, 2, 3, 6, 7, and 9, the bump solidification step S3 is a step in which bumps γ are solidified to bond semiconductor chips β to the substrate α. In the bump solidification step S3, when the control device 30 determines that bumps γ have dissolved in the bump dissolution determination step S2, it switches the control of the servo motor 23 of the pressing unit drive device 22 to position control (see Figure 9). The control device 30 transmits a position control signal to the servo amplifier 24 to move the pressing unit stage 25 to a reference position P2, which is the position of the pressing unit stage 25 when mounting semiconductor chips β on the substrate α at predetermined intervals (see Figure 2). The servo amplifier 24 supplies power to the servo motor 23 to move the pressing unit stage 25 to the reference position P2. The servo motor 23 moves the pressing unit stage 25 to the reference position P2 (see Figure 9). Therefore, the mounting device 1 uses the pressing unit 21 to position the semiconductor chip β at a predetermined position on the substrate α, at a reference position P2 at a predetermined distance from the substrate α. Furthermore, the control device 30 transmits control signals to the first heater 13 and the second heater 28 to stop them. Thus, the mounting device 1 holds the semiconductor chip β in the predetermined position relative to the substrate α.

[0061] As shown in Figure 7, bump γ shrinks as solidification progresses. Therefore, a force F1 is generated on bump γ and the pressing unit stage 25 in a direction that pulls the semiconductor chip β body toward the substrate α. Also, the pressing unit stage 25 and the second attachment 29, which were thermally expanded due to heating, shrink as the temperature decreases. In other words, the semiconductor chip β moves away from the reference position P2 toward the substrate α due to the contraction of the pressing unit stage 25 and the second attachment 29. Therefore, a force F2 acts on the pressing unit stage 25, which holds the semiconductor chip β via bump γ and the second attachment 29, which is the reaction force to the force that pulls the semiconductor chip β away from the substrate α by moving the semiconductor chip β. Thus, forces F1 and F2, which are forces that pull the semiconductor chip β body toward the substrate α, are applied to the pressing unit stage 25.

[0062] As shown in Figures 1, 2, 3, 8, and 9, the gap adjustment step S4 is a step in which the gap between the substrate α and the semiconductor chip β is adjusted. In the gap adjustment step S4, if the forces F1 and F2 that pull the pressing unit stage 25 and the second attachment 29 toward the substrate α, as measured by the load sensor 26, are greater than or equal to the reference upper limit value Fmax, the control device 30 switches the control of the servo motor 23 of the pressing unit drive device 22 to torque control (see Figure 9). The control device 30 moves the pressing unit stage 25 by the pressing unit drive device 22 so that a force that presses the semiconductor chip β toward the substrate α is applied to the semiconductor chip β (see Figure 8). Furthermore, if the force that pulls the pressing unit stage 25 towards the substrate α, as measured by the load sensor 26, is less than the reference lower limit value Fmin, the control device 30 stops the movement of the pressing unit stage 25 and the second attachment 29 by the pressing unit drive device 22 and maintains the stopped positions of the pressing unit stage 25 and the second attachment 29.

[0063] In this manner, the mounting apparatus 1, which mounts semiconductor chips β onto substrate α, determines the dissolution of bumps γ, which are difficult to visually inspect with a camera 20a or the like, by measuring the force applied to the pressing unit stage 25 and the second attachment 29 during the bump dissolution determination step S2 and the bump solidification step S3. This allows the mounting apparatus 1 to indirectly determine the dissolution of bumps γ.

[0064] Furthermore, in the bump dissolution determination step S2, the mounting apparatus 1 moves the pressing unit stage 25 and the second attachment 29 to the reference position P2 by torque control while the bump γ is not dissolved. Therefore, in a solidified state where the semiconductor chip β can support the semiconductor chip β body, the stress generated by pressing the semiconductor chip β against the substrate α with torque control whose output is limited is smaller than the stress generated by moving the semiconductor chip β to the reference position P2 by position control whose output force is not limited.

[0065] Furthermore, in the bump solidification process S3, the mounting apparatus 1 moves the semiconductor chip β by position control, which determines the holding position when the bumps γ have dissolved. Since the semiconductor chip β is held at the reference position P2 when it is determined that the bumps γ have dissolved, it is possible to suppress short circuits between adjacent bumps γ and short circuits with adjacent wiring on the substrate α.

[0066] Furthermore, in the gap adjustment process S4, if the pressing unit stage 25, the second attachment 29, and the bump γ shrink due to a decrease in temperature, the mounting device 1 moves the pressing unit stage 25 and the second attachment 29 toward the substrate α by torque control.

[0067] The mounting apparatus 1 moves the pressing unit stage 25 and the second attachment 29 so as to apply a force to the bump γ that counteracts the tensile force generated in the bump γ due to the contraction of the pressing unit stage 25 and the second attachment 29. As a result, the gap between the semiconductor chip β and the substrate α, which increased due to the contraction of the pressing unit stage 25 and the second attachment 29, decreases due to the movement of the semiconductor chip β. Furthermore, the tensile force on the bump γ, which was generated by the contraction of the pressing unit stage 25 and the second attachment 29 and the contraction of the bump γ, is reduced by the movement of the semiconductor chip β. Therefore, the stress generated in the bump γ due to the semiconductor chip β being pulled towards the substrate α by solidification is suppressed by applying a force to the semiconductor chip β that presses it against the substrate α using torque control.

[0068] Furthermore, the control device 30 transmits a control signal to the servo amplifier 24 that constitutes the pressing unit drive device 22. The servo amplifier 24, having received the control signal from the control device 30, moves the pressing unit stage 25 and the second attachment 29 while acquiring a feedback signal from the encoder 23a or the load sensor 26. At this time, the servo amplifier 24 processes the acquired feedback signal without transmitting it to the control device 30. Therefore, since the pressing unit drive device 22 controls the servo motor 23 by the servo amplifier 24, it can be controlled at a faster speed than when the control device 30 outputs a control signal to the servo amplifier 24 based on the feedback signal. As a result, the generation of stress in the bump γ due to temperature changes during bonding can be suppressed, and the connection quality between the substrate α and the semiconductor chip β can be improved.

[0069] Thus, even if the semiconductor chip β moves due to the contraction of the pressing unit stage 25 and the second attachment 29, the mounting apparatus 1 can adjust the distance between the substrate α and the semiconductor chip β within an appropriate range relative to the reference position P2, using the tensile force applied to the pressing unit stage 25 and the second attachment 29 as an indicator. Furthermore, the mounting apparatus 1 can reduce the stress generated in the bump γ due to the contraction of the pressing unit stage 25 and the second attachment 29 and the contraction of the bump γ as the temperature decreases, using the tensile force as an indicator. This suppresses the generation of stress in the bump γ due to temperature changes during bonding, and improves the connection quality between the substrate α and the semiconductor chip β.

[0070] <Other implementation methods> Next, another mounting method for the semiconductor chip β in the mounting apparatus 1 will be described using Figure 10. Figure 10 is a graph showing the position of the pressing unit stage 25, the force applied to the pressing unit stage 25, and the temperature of the pressing unit stage 25 when mounting the semiconductor chip β on the substrate α in another mounting method according to an embodiment of the present invention.

[0071] In the bump dissolution determination step S2 described above, if the amount of movement of the pressing unit stage 25 in the Z direction from the position where the semiconductor chip β contacts the substrate α is greater than or equal to the dissolution determination distance L0, it is determined that the bump γ has dissolved (see Figures 3, 5, and 9). However, as shown in Figure 10, the control device 30 may also be configured to determine that the bump γ has dissolved if the force in the direction of pressing the pressing unit stage 25 and the second attachment 29 against the substrate α, as measured by the load sensor 26, decreases to less than or equal to the dissolution determination force change amount F0.

[0072] The mounting apparatus 1 determines the melting of bump γ by the change in the melting determination force F0 applied to the pressing unit stage 25 and the second attachment 29. This allows for indirect determination of bump γ melting. This suppresses the generation of stress in bump γ due to temperature changes during bonding, thereby improving the connection quality between the substrate α and the semiconductor chip β.

[0073] In the gap adjustment step S4 described above, the control device 30 moves the pressing unit stage 25 by the pressing unit drive device 22 so that a force is applied to the semiconductor chip β in a direction that presses the semiconductor chip β against the substrate α if the force in the direction that pulls the pressing unit stage 25, measured by the load sensor 26, is greater than or equal to a reference upper limit value Fmax (see Figures 3, 8, and 9). However, as shown in Figure 10, the control device 30 may also move the pressing unit stage 25 by the pressing unit drive device 22 so that a force is applied to the semiconductor chip β in a direction that presses the semiconductor chip β against the substrate α if the position change of the pressing unit stage 25 and the second attachment 29 in the direction relative to the reference position P2 is greater than or equal to a reference upper limit change amount Lmax.

[0074] If the amount of change in the semiconductor chip β measured by the encoder 23a is greater than or equal to the reference upper limit change Lmax, the mounting device 1 moves the pressing unit stage 25 and the second attachment 29 until the force pulling the pressing unit stage 25 toward the substrate α is less than the reference lower limit Fmin, thereby applying a force to press the semiconductor chip β toward the substrate α. The gap between the semiconductor chip β and the substrate α, which increased due to the contraction of the pressing unit stage 25 and the second attachment 29, decreases due to the movement of the semiconductor chip β. Furthermore, the tensile force of the bump γ, which was generated by the contraction of the pressing unit stage 25 and the second attachment 29 and the contraction of the bump γ, is reduced by the movement of the semiconductor chip β. This improves the connection quality between the substrate α and the semiconductor chip β.

[0075] In the gap adjustment step S4 described above, if the force that pulls the pressing unit stage 25 towards the substrate α, as measured by the load sensor 26, is less than the reference lower limit value Fmin, the control device 30 stops the movement of the pressing unit stage 25 and the second attachment 29 by the pressing unit drive device 22 and maintains the stopped positions of the pressing unit stage 25 and the second attachment 29. However, the control device 30 may also be configured to stop the movement of the pressing unit stage 25 and the second attachment 29 and maintain the stopped positions of the pressing unit stage 25 and the second attachment 29 after a predetermined time has elapsed since the start of torque control of the pressing unit drive device 22.

[0076] In the above configuration, the mounting apparatus 1 maintains the positions of the pressing unit stage 25 and the second attachment 29 after a predetermined time has elapsed since the start of mounting the semiconductor chip β, and terminates the mounting control of the semiconductor chip β. Therefore, the mounting apparatus 1 does not repeatedly apply force to the semiconductor chip β against the bump γ more than a certain number of times. This suppresses the generation of stress in the bump γ due to temperature changes during bonding, and improves the connection quality between the substrate α and the semiconductor chip β.

[0077] [Other embodiments]

[0078] In the above-described embodiment 1, the mounting apparatus 1 positions the semiconductor chip β relative to the substrate α using a pickup unit 20. However, the mounting apparatus may also be configured to position the substrate α relative to the semiconductor chip β using a stage.

[0079] Furthermore, in the above-described embodiment 1, the mounting apparatus 1 holds the substrate α with the first attachment 14 and the semiconductor chip β with the second attachment 29. However, the mounting apparatus may also be configured to hold the semiconductor chip β with the first attachment and the substrate α with the second attachment.

[0080] Furthermore, in the above-described embodiment 1, the mounting device 1 adjusts the inclination of the pressing unit stage 25 with respect to the object using the air gyro 27. However, the mounting device may also be configured without an air gyro.

[0081] Furthermore, in the above-described embodiment 1, the mounting device 1 heats the first attachment 14 with the first heater 13 and the second attachment 29 with the second heater 28. However, the mounting device may also be configured to heat the corresponding attachment with at least one of the first heater or the second heater.

[0082] Furthermore, in the above-described embodiment 1, the mounting device 1 uses the average value of the measured values ​​of the three load sensors 26 as the force applied to the semiconductor chip β. However, the mounting device may, for example, use the average value of the measured values ​​of the multiple load sensors, excluding the maximum and minimum values, as the force applied to the semiconductor chip β. Alternatively, the mounting device may calculate the force applied to the semiconductor chip β using statistical methods.

[0083] Furthermore, in Embodiments 1 and 2 described above, the mounting apparatus 1 heats the first attachment 14 with a first heater 13, which is a ceramic heater, and heats the second attachment 29 with a second heater 28. However, the mounting apparatus may also be configured to heat the attachments with a constant heater or a pulse heater.

[0084] Although embodiments of the present invention have been described above, the embodiments described above are merely examples for carrying out the present invention. Therefore, the invention is not limited to the embodiments described above, and it is possible to carry out the invention by appropriately modifying the embodiments described above without departing from the spirit of the invention. [Explanation of symbols]

[0085] 1. Mounting device 10 Stage Units 11 Stage drive unit 12 stages 13. First heater 14. Attachment 1 20 Pickup Units 20a Camera 21 Pressing Unit 21a Pickup unit drive device 22 Pressing Unit Drive Device 23 Servo motors 23a encoder 24 Servo Amplifier 25 Pressing Unit Stage 26 Load Sensor 27 Air Gyro 28. Second heater 29. Second Attachment 30 Control device L0 Dissolution judgment distance F0 Dissolution determination value change P1 contact position P2 reference position F1, F2 force Fmax upper limit Fmin Lower Limit α substrate β semiconductor chip γ Bump S1 Bump heating process S2 Bump dissolution determination process S3 Bump solidification process S4 Gap adjustment process

Claims

1. A stage on which a substrate for mounting semiconductor chips is placed, A pressing unit is positioned opposite the stage, moves to any position toward the stage, and applies any force to the substrate and the semiconductor chip; A heating section, supported by the pressing section, heats the semiconductor chip, A holding portion supported by the heating portion and holding the semiconductor chip, It has a control unit that controls the pressing unit and the heating unit, A mounting apparatus for pressing the semiconductor chip held by the holding unit onto the substrate on the stage, heating the semiconductor chip with the heating unit to melt the bumps, and bonding the semiconductor chip to the substrate, A position measuring unit for measuring the position of the holding part, It has a force measuring unit that measures the force applied to the holding part, The control unit, The position of the holding part is obtained by the position measuring unit, The force applied to the holding part, measured by the force measuring unit, is acquired. When the semiconductor chip is pressed against the substrate by the pressing unit and heated by the heating unit, if it is determined that the bumps on the semiconductor chip have melted based on at least one of the acquired position of the holding unit and the force applied to the holding unit, the pressing unit holds the holding unit at a reference position for mounting the semiconductor chips on the substrate at predetermined intervals and stops heating the semiconductor chip by the heating unit. If the force applied by the force measuring unit to pull the holding portion toward the substrate is greater than or equal to a reference upper limit, or if the positional change of the holding portion toward the substrate in the thickness direction relative to the reference position is greater than or equal to a reference upper limit change, the pressing unit moves the holding portion so that a force is applied to the semiconductor chip toward the substrate. If the force measured by the force measuring unit in the direction of pulling the holding unit toward the substrate is less than a reference lower limit, or if the positional change of the holding unit toward the substrate thickness relative to the reference position is less than a reference lower limit change, the movement of the holding unit by the pressing unit is stopped and the stopped position of the holding unit is maintained. Mounting device.

2. In the mounting apparatus described in claim 1, The control unit, In a state where the semiconductor chip is pressed against the substrate by the pressing part and the semiconductor chip is heated by the heating part, When the holding portion moves toward the substrate beyond the melting determination distance, or when the force applied by the force measuring unit to press the holding portion toward the substrate decreases to or below the melting determination force, it is determined that the bump of the semiconductor chip has melted. Mounting device.

3. In the mounting apparatus described in claim 1, The control unit, The pressing portion is controlled by torque control, which controls the force applied to the holding portion as a reference, until it is determined that the bumps of the semiconductor chip have melted. Once it is determined that the bumps of the semiconductor chip have melted, the pressing portion is controlled by switching to position control, which controls the position of the holding portion as a reference. If the force pulling the holding portion toward the substrate exceeds a reference upper limit, or if the positional change of the holding portion toward the substrate in the thickness direction relative to the reference position exceeds a reference upper limit, the pressing portion is controlled by the torque control. If the force applied by the force measuring unit to pull the holding unit toward the substrate is less than a reference lower limit, or if the positional change of the holding unit toward the substrate in the thickness direction relative to the reference position is less than a reference lower limit change, the pressing unit is controlled by the position control. Mounting device.

4. In the mounting apparatus described in claim 3, The control unit, When the force pulling the holding portion toward the substrate exceeds a reference upper limit, or when the positional change of the holding portion toward the substrate in the thickness direction relative to the reference position exceeds a reference upper limit, the movement of the holding portion is stopped and the stopped position of the holding portion is maintained after a predetermined time has elapsed since the start of control of the pressing portion by torque control. Mounting device.

5. In the mounting apparatus described in claim 1, The pressing portion is, The servo motor and the servo amplifier which supplies current to the servo motor based on a control signal from the control unit are included. The position measuring unit is, Includes an encoder for detecting the rotation angle of the servo motor, The aforementioned servo amplifier, Based on the control signal from the control unit, current is supplied to the servo motor, and when a feedback signal is obtained from the servo motor, current is supplied to the servo motor based on the difference between the control signal and the feedback signal. Mounting device.

6. A method for mounting a semiconductor chip, comprising pressing and heating the semiconductor chip to melt the bumps on the semiconductor chip and mounting it onto a substrate, A bump heating step in which the semiconductor chip is pressed against the substrate with a predetermined force and heated, A bump dissolution determination step in which it is determined that the bump has dissolved when the semiconductor chip pressed against the substrate moves toward the substrate beyond the dissolution determination distance, If it is determined in the bump dissolution determination step that the bumps have dissolved, a bump solidification step is performed in which the semiconductor chips are held at reference positions for mounting the semiconductor chips on the substrate at predetermined intervals and the heating of the semiconductor chips is stopped. The solidification step includes a gap adjustment step in which, if the force applied to the semiconductor chip held at the reference position in the direction of attracting the semiconductor chip to the substrate is greater than or equal to a reference upper limit, or if the change in the position of the semiconductor chip in the thickness direction of the substrate relative to the reference position is greater than or equal to a reference upper limit change, a force is applied in the direction of pressing the semiconductor chip to the substrate; and if the force applied to the semiconductor chip in the direction of attracting the semiconductor chip to the substrate is less than a reference lower limit, or if the change in the position of the semiconductor chip in the thickness direction of the substrate relative to the reference position is less than a reference lower limit change, the movement of the semiconductor chip is stopped and the stopped position of the semiconductor chip is maintained. Methods for mounting semiconductor chips.

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