JP4508151B2 - Bonding apparatus and bonding method - Google Patents

Description

  The present invention relates to a bonding apparatus and a bonding method for bonding a bonded body such as a flip chip on which bonding bumps are formed to a bonded body such as a substrate.

As a device for bonding a bonded body such as a flip chip to a bonded body such as a substrate, the bonded body is held by a bonding tool equipped with a vibrator, and the bonded body vibrates while being pressed against the bonded body. The vibration is applied to the bonded body by transmitting the friction between the bonded surface of the bonded body (for example, a bump formed on a flip chip) and the bonded surface of the bonded body (for example, an electrode on the substrate). There is known an ultrasonic bonding apparatus that causes both of them to be bonded (see Patent Document 1).
Japanese Patent No. 3565063

  By the way, since only one bonded body can be held in the bonding tool, there is a limit in tact-up in the conventional bonding apparatus that performs bonding with only one bonding tool.

  Therefore, an object of the present invention is to provide a bonding apparatus and a bonding method that enable continuous bonding with a plurality of independent bonding tools.

  The bonding apparatus according to claim 1, a plurality of bonding tools that transmit a load and vibration to the bonded body, a load applying unit that applies a load to the plurality of bonding tools and presses the bonded body against the bonded body, A plurality of vibration applying means provided corresponding to the plurality of bonding tools and independently applying vibrations to the corresponding bonding tools, and a high frequency voltage for generating a high frequency voltage applied to any of the plurality of vibration applying means A generating unit; and a selecting unit that selects any one of the bonding tools to which the high-frequency voltage is applied. The high-frequency voltage is applied to any one of the bonding tools selected by the selecting unit.

  The bonding apparatus according to claim 2 is the bonding apparatus according to claim 1, wherein the fundamental frequency unique to each of the plurality of bonding tools and the voltage of the high-frequency voltage applied to the vibration applying means of the plurality of bonding tools are respectively used. A storage unit that stores values corresponding to the plurality of bonding tools, and the high-frequency voltage generation unit includes the basic frequency and the voltage value corresponding to any one of the bonding tools selected by the selection unit. A high frequency voltage is generated based on the above, and an equivalent vibration power is generated in any of the plurality of bonding tools.

The bonding method according to claim 3, wherein a plurality of bonding tools for transmitting a load and vibration to the bonded body, a load applying means for applying a load to the plurality of bonding tools and pressing the bonded body against the bonded body, A plurality of vibration applying means provided corresponding to the plurality of bonding tools and independently applying vibrations to the corresponding bonding tools, and a high frequency voltage for generating a high frequency voltage applied to any of the plurality of vibration applying means A bonding method in a bonding apparatus, comprising: a generation unit; and a selection unit that selects any one of the bonding tools to which the high-frequency voltage is applied, the step of selecting any one of the plurality of bonding tools Generating a high-frequency voltage to be applied to the selected bonding tool; and The high-frequency voltage and a step of bonding the bonded body by applying a load to the object to be bonded to the selected bonding tool is applied with the vibration applying unit of the selected bonding tool.

  According to a fourth aspect of the present invention, there is provided the bonding method according to the third aspect, wherein the bonding apparatus has a fundamental frequency unique to each of the plurality of bonding tools and vibration applying means for the plurality of bonding tools. A storage unit that stores a voltage value of the high-frequency voltage to be applied in association with the plurality of bonding tools; and in the step of generating the high-frequency voltage, the basic corresponding to any of the selected bonding tools A high frequency voltage is generated based on the frequency and the voltage value, and an equivalent vibration power is generated in any of the plurality of bonding tools.

  According to the present invention, continuous bonding by a plurality of independent bonding tools is possible, and tact up can be realized.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of a bonding apparatus according to an embodiment of the present invention, and FIG. 2 is a flowchart showing a bonding operation in the bonding apparatus according to the embodiment of the present invention.

  First, the overall configuration of the bonding apparatus in the present embodiment will be described with reference to FIG. The bonding apparatus is an apparatus for bonding a bonded body to a bonded body by applying a load and vibration. In the bonding apparatus 1 according to the present embodiment, the load and vibration are applied to the chip 3 held by the bonding tool 2. A bonding operation of applying and bonding to the substrate 5 held on the bonding stage 4 is executed. The bonding tool 2 is composed of a horn or the like, and is provided with an action part 2a for adsorbing and holding the chip 3 as a bonded body at the lower part. The bonding stage 4 is mounted on a moving table 6, and is configured to be horizontally movable in a state in which a substrate 5 as a bonded body is held horizontally. The moving table 6 functions as a positioning means for relatively positioning a bonding portion set in advance on the substrate 5 below the chip 3 by horizontally moving the substrate 5 held on the bonding stage 4.

  The bonding apparatus 1 includes a plurality of bonding tools 2 and is configured to be able to apply a load and vibration to the chip 3 held by each bonding tool 2. Each bonding tool 2 is mounted on a plurality of lifting heads 8 that can be lifted and lowered independently of the lifting mechanism 7. Each bonding tool 2 is provided with a plurality of vibrators 9 each composed of a piezoelectric element or the like, and the horn resonates due to ultrasonic vibration generated by the electrostrictive action of the piezoelectric element or the like. A predetermined vibration power is generated by applying vibration to the chip 3 held by 2a. When the bonding tool 2 is lowered while the chip 3 is held on the action part 2a, the bump 3a formed on the bonding surface of the chip 3 comes into contact with the substrate 5 and further lowered to apply a load to the chip 3. Press against the substrate 5. At this time, when vibration is applied to the chip 3, the oxide film and organic contaminants at the bonding interface are removed at the initial application stage, and the bonding between the chip 3 and the substrate 5 is completed when a preset application time or energy is reached. . As described above, the lifting mechanism 7 functions as a load applying unit that applies a load to the chip 3, and adjusts the load applied to the chip 3 by adjusting the lifting / lowering movement amount of the lifting head 8. Further, the vibrator 9 functions as a vibration applying unit that applies vibration to the chip 3.

The bonding apparatus 1 includes a control unit 10 that controls a bonding operation, and is configured such that each driving unit performs a predetermined operation in response to a control signal transmitted from the control unit 10. The control unit 10 includes a storage unit 11 in which various data and programs necessary for controlling the bonding operation, for example, data related to the chip 3, data related to bonding points set on the substrate 5, and a control program related to the bonding operation are stored in advance. The bonding operation is controlled based on these data and programs.

  In the bonding apparatus 1, the bonding operation is controlled so that the plurality of chips 3 are bonded to the plurality of bonding portions set on the substrate 5 with appropriate strength. For this reason, work data such as bonding conditions, that is, bonding load, bonding time, and vibration power in each bonding tool 2 are stored in the storage unit 11 in advance. The vibration power is generally set by a power value, but may be set by a current value, a vibration amplitude value of the action part 2a, etc. in addition to the power value. In addition, since there are many types of chips 3 having different materials and dimensions, the bonding conditions are set and stored for each type of chip 3 handled in the bonding apparatus.

  Of the bonding conditions, the vibration power is set by the high-frequency voltage applied to each vibrator 9, so a high-frequency voltage control unit 20 that controls the high-frequency voltage applied to each vibrator 9 is provided. The high-frequency voltage control unit 20 has a function of adjusting the frequency of the high-frequency voltage applied to each vibrator 9 and the applied voltage, and applies a high-frequency voltage corresponding to the bonding tool 2 for performing bonding to the vibrator 9 and bonding. Control of making the frequency of the high frequency voltage applied to the vibrator 9 follow the fluctuation of the resonance frequency by monitoring the fluctuation of the resonance frequency inside.

  The high-frequency voltage generation unit 21 has a function of generating a voltage having a predetermined frequency and applying the voltage to each vibrator 9. Even if each bonding tool 2 has the same shape, there are some individual differences particularly in vibration characteristics. Therefore, in order to obtain the same vibration power in each bonding tool 2, the voltage value corresponding to each bonding tool 2 is It is desirable to apply a voltage of frequency. As the reference (initial value) frequency, the fundamental frequency of each bonding tool 2 (resonance frequency when the bonding tool 2 is oscillated in the air without a load applied) is used. Further, the voltage value of the voltage to be applied is set based on the correlation between the applied voltage value and vibration power (for example, power value) in each bonding tool 2 and is necessary for generating the same vibration power in each bonding tool 2. The voltage value is set corresponding to each bonding tool 2. The frequency and voltage value set corresponding to each bonding tool 2 are stored in the storage unit 11, and a high-frequency voltage having a frequency and voltage value corresponding to the bonding tool 2 that performs bonding is generated in the high-frequency voltage generation unit 21. 9 is applied.

  The high-frequency voltage generation unit 21 and the vibrator 9 of each bonding tool 2 are connected via a connection switching unit 22 so that energization is possible. The connection switching unit 22 is constituted by a semiconductor relay such as a photo moss relay, and performs bonding by switching the connection between each vibrator 9 and the high-frequency voltage generation unit 21 in response to a control signal from the control unit 10. A high frequency voltage is applied to the tool 2. Since the bonding apparatus 1 includes three bonding tools 2 for one substrate 5, a high frequency voltage is applied to each vibrator 9 of the three bonding tools 2 in a predetermined order, and each bonding tool 2 is applied. Throughput is improved by continuously bonding the held chips 3 to the substrate 5. The connection switching unit 22 functions as a selection unit that selects the bonding tool 2 to which the high frequency voltage generated by the high frequency voltage generation unit 21 is applied.

The detection unit 23 has a function of detecting the voltage and current of power supplied to the vibrator 9. The voltage and current detected by the detection unit 23 are transmitted to the phase comparison unit 24. In general, when a load is applied to the bonding tool 2 during bonding, the vibration characteristics of the horn constituting the bonding tool 2 may change and the resonance frequency may vary. As a result, a deviation occurs from the fundamental frequency applied as the reference (initial value) frequency, and the vibration power decreases. Therefore, the phase comparison means 24 detects the resonance frequency fluctuation amount Δf from the phase difference between the voltage and the current and transmits it to the high frequency voltage generator 21, and the frequency of the high frequency voltage applied to the vibrator 9 from the high frequency voltage generator 21 Control is performed to change the resonance frequency of the bonding tool 2 to follow the fluctuation.

  In this way, the bonding apparatus 1 stores in advance the bonding conditions common to all the bonding tools 2, and the vibration power of the bonding conditions is the frequency of the voltage applied to the vibrator 9 corresponding to each bonding tool 2. And the voltage value is stored. Therefore, by controlling the bonding operation based on the bonding condition set by the frequency and voltage value corresponding to the bonding tool 2 that executes the bonding operation, it is possible to generate the same vibration power in all the bonding tools 2. Thus, it is possible to achieve uniform bonding by eliminating variations in bonding quality for each bonding tool 2. In addition, since a single high-frequency voltage generator 21 can apply a high-frequency voltage to a plurality of bonding tools 2, the bonding apparatus 1 can be reduced in size and cost can be reduced.

  Next, the bonding operation in the bonding apparatus 1 will be described in the order of steps. First, a bonding condition serving as basic data for bonding operation control is set (ST1). Specifically, the data is stored in the storage unit 11 as work data such as bonding load, bonding time, and vibration power. Among these, the vibration power is set corresponding to each bonding tool 2, and the fundamental frequency and the voltage value are stored corresponding to the bonding tool 2. Next, one of the plurality of bonding tools 2 provided in the bonding apparatus 1 is selected (ST2). The bonding operation is controlled according to a control program stored in advance in the storage unit 11, and the connection between the bonding tool 2 and the high-frequency voltage generation unit 21 is switched in the order programmed in advance. It is also possible for the operator to select an arbitrary bonding tool 2 by operating the connection switching unit 22 that is a selection means. Next, a high frequency voltage corresponding to the selected bonding tool 2 is generated (ST3). The frequency and voltage value set corresponding to each bonding tool 2 are stored in the storage unit 11, and a high frequency voltage having a basic frequency and a voltage value corresponding to the selected bonding tool 2 is generated in the high frequency voltage generation unit 21. Is done.

  Next, a load and vibration are applied to the selected bonding tool 2 to bond the chip 3 to a predetermined bonding location on the substrate 5 (ST4). These loads and vibrations are set based on the bonding conditions stored in the storage unit 11 and controlled so as to be bonded with appropriate strength. Further, the moving table 6 is controlled based on the bonding portion data of the substrate 5 stored in the storage unit 11, and the bonding portion of the substrate 5 is positioned below the chip 3 held by the bonding tool 2.

  Through the above steps, the bonding operation for bonding the chip 3 held by any one of the bonding tools 2 to a predetermined bonding portion of the substrate 5 is completed, and thereafter the steps ST2 to ST4 are repeated to perform pre-programmed mounting. The chip 3 is joined to all the places. In the bonding apparatus 1, a high frequency voltage is applied to each vibrator 9 of the three bonding tools 2 in a predetermined order, and the chips 3 held in the bonding tools 2 are continuously bonded to the substrate 5 to improve the throughput. I am letting.

  According to the present invention, continuous bonding with a plurality of independent bonding tools is possible, and tact-up can be realized, which is useful in the field of bonding a large number of chips to a substrate.

1 is an overall configuration diagram of a bonding apparatus according to an embodiment of the present invention. The flowchart which shows the bonding operation | movement in the bonding apparatus of embodiment of this invention.

Explanation of symbols

1 Bonding device 2 Bonding tool 3 Chip (joint)
5 Substrate (bonded body)
7 Lifting mechanism (load application means)
9 vibrator (vibration applying means)
DESCRIPTION OF SYMBOLS 10 Control part 11 Memory | storage part 21 High frequency voltage generation part 22 Connection switching part (selection means)

Claims (4)

A plurality of bonding tools that transmit load and vibration to the joined body;
A load applying means for applying a load to the plurality of bonding tools to press the bonded body against the bonded body;
A plurality of vibration applying means that are provided corresponding to the plurality of bonding tools and independently apply vibrations to the corresponding bonding tools;
A high-frequency voltage generator that generates a high-frequency voltage to be applied to any of the plurality of vibration applying means;
Selection means for selecting any bonding tool to apply the high-frequency voltage;
With
A bonding apparatus for applying the high-frequency voltage to any one of the bonding tools selected by the selection means. A storage unit that stores a fundamental frequency unique to each of the plurality of bonding tools and a voltage value of the high-frequency voltage applied to the vibration applying unit of the plurality of bonding tools in association with the plurality of bonding tools; Prepared,
The high-frequency voltage generation unit generates a high-frequency voltage based on the fundamental frequency and the voltage value corresponding to any one of the bonding tools selected by the selection unit, and is equivalent in any of the plurality of bonding tools. The bonding apparatus according to claim 1, wherein vibration power is generated. A plurality of bonding tools that transmit load and vibration to the joined body;
A load applying means for applying a load to the plurality of bonding tools to press the bonded body against the bonded body;
A plurality of vibration applying means that are provided corresponding to the plurality of bonding tools and independently apply vibrations to the corresponding bonding tools;
A high-frequency voltage generator that generates a high-frequency voltage to be applied to any of the plurality of vibration applying means;
Selection means for selecting any bonding tool to apply the high-frequency voltage;
A bonding method in a bonding apparatus comprising:
Selecting any one of the plurality of bonding tools;
Generating a high frequency voltage to be applied to the selected bonding tool;
Applying the generated high-frequency voltage to the vibration applying means of the selected bonding tool and applying a load to the selected bonding tool to bond the bonded body to the bonded body;
Including bonding method. The bonding apparatus stores the fundamental frequency unique to each of the plurality of bonding tools and the voltage value of the high-frequency voltage applied to the vibration applying means of the plurality of bonding tools in association with the plurality of bonding tools. A storage unit
In the step of generating the high-frequency voltage, a high-frequency voltage is generated based on the fundamental frequency and the voltage value corresponding to any one of the selected bonding tools, and the same vibration power in any of the plurality of bonding tools The bonding method according to claim 3, wherein:

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