Manufacturing device and manufacturing method of junction

Abstract

To provide a manufacturing device of a junction, capable of preferably transferring a joint material to a chip.SOLUTION: A manufacturing device of a junction 10 comprises: a stage 12 to which a transfer sheet 110 into which a release sheet 112 and a joint material 114 are laminated is mounted, and which sucks and holds the transfer sheet 110; and a tool head 14 that includes a suction tool 30 that holds a chip 102; and a controller 16. The controller 16 moves the suction tool 30 in a state where the chip 102 is held so as to press the chip 102 to the joint material 114, and thereby jointing the joint material 114 to the chip 102, and a suction and a suction cancellation of the transfer sheet 110 by the stage 12 can be switched so as to be linked to a movement of the suction tool 30.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This specification discloses a bonded body manufacturing apparatus and a bonded body manufacturing method for manufacturing a bonded body formed by transferring a bonding material to a chip.

Background Art

[0002] In recent years, in order to bond a chip to a circuit board, it has been proposed to use sintering bonding using metal nanoparticles or microparticles such as silver (Ag). In order to enable such sintering bonding, it has been proposed to previously transfer a bonding material made of a sintering material to the lower surface of the chip.

[0003] For example, Patent Document 1 discloses a technique for transferring a bonding material (referred to as a "sintering film" in Patent Document 1) to a chip. In Patent Document 1, the bonding material is transferred to the chip by pressing and heating the chip in a state where the bonding material is in contact with the chip.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the bonding between the chip and the bonding material is weak, there is a risk that a part of the bonding material peels off from the chip when the chip is lifted after the bonding process. In other words, there is a risk that a part of the bonding material transferred to the chip is chipped.

[0006] Therefore, this specification discloses a bonded body manufacturing apparatus and a bonded body manufacturing method capable of more favorably transferring a bonding material to a chip.

Means for Solving the Problems

[0007] The bonding body manufacturing apparatus disclosed in this specification includes a stage on which a transfer sheet with a release sheet and a bonding material laminated thereon is placed, and which sucks and holds the transfer sheet, a tool head having a tool for holding a chip, and a controller. The controller moves the tool relative to the transfer sheet to ground the held chip to the bonding material for bonding, and then separates the chip from the release sheet. In conjunction with the separation of the tool, the controller is configured to adjust the suction force of the transfer sheet by the stage or the tension of the transfer sheet.

[0008] In this case, the controller may be configured to raise the tool together with the chip in a state where the suction of the transfer sheet by the stage is released after the tool is grounded to the bonding material, and then resume the suction of the transfer sheet.

[0009] Also, the controller may resume the suction by the stage at the timing when the chip reaches a specified resumption height.

[0010] In this case, the resumption height may be a variable value that changes according to at least one of the type of the chip and the position of the transfer area transferred to the chip within the transfer sheet.

[0011] Also, the stage may be capable of partially switching the suction state of the transfer sheet, and the controller may be configured to release the suction of the transfer sheet only within a certain range from the transfer area transferred to the chip after bonding the bonding material.

[0012] Also, the tool head may have a vibration source that applies ultrasonic vibration to the chip, and the controller may be further configured to apply ultrasonic vibration to the chip at the timing when the chip is pressed against the bonding material.

[0013] The method for manufacturing a bonded body disclosed in this specification is characterized in that a transfer sheet in which a release sheet and an adhesive are laminated is sucked and held on a stage, and a tool holding the chip is moved so as to press the chip against the adhesive, thereby bonding the adhesive to the chip, and the suction and release of the transfer sheet by the stage are switched in conjunction with the movement of the tool.

Advantages of the Invention

[0014] According to the technology disclosed in this specification, since the suction and release of the transfer sheet are switched in conjunction with the movement of the tool, and thus the chip, excessive force can be prevented from being applied to the adhesive bonded to the chip. As a result, chipping of the adhesive can be effectively prevented, and the adhesive can be more favorably transferred to the chip.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0016] Hereinafter, the configuration of the bonded body manufacturing apparatus 10 will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of the bonded body manufacturing apparatus 10. In FIG. 1, for ease of viewing, the dimensional ratios of the respective members are greatly changed from the actual dimensional ratios. In particular, the thickness of the transfer sheet 110 with respect to the size of the chip 102 is shown to be significantly larger than the actual one. Actually, for example, when one side of the chip 102 is several millimeters, the thickness of the transfer sheet 110 is several tens of μm, or around 100 μm.

[0017] The bonded body manufacturing apparatus 10 transfers the bonding material 114 onto the bottom surface of the semiconductor chip (hereinafter referred to as "chip 102") in order to obtain a bonded body 100 (see FIG. 2) in which the bonding material 114 is bonded to the chip 102. Such a bonded body manufacturing apparatus 10 includes a stage 12, a tool head 14, and a controller 16.

[0018] The stage 12 has the transfer sheet 110 placed thereon and sucks the transfer sheet 110. The transfer sheet 110 is a sheet in which the bonding material 114 and the release sheet 112 are laminated. The release sheet 112 is a sheet that supports the bonding material 114 and is made of, for example, resin. The bonding material 114 is made of, for example, metal and is a thin film transferred to the chip 102. Such a bonding material 114 is, for example, a film-like sintering bonding composition containing at least conductive metal-containing sinterable particles and a binder component. The sinterable particles are particles containing a conductive metal element and capable of sintering. The sinterable particles are composed of, for example, gold, silver, copper, palladium, tin, nickel, and an alloy of two or more metals selected from this group. Cuts 115 corresponding to the shape of the chip 102 described later may be formed in advance in such a bonding material 114. For example, when the chip 102 is a rectangle of a predetermined size, cuts may be formed in a lattice pattern in the bonding material 114 so that rectangles of a predetermined size are arranged.

[0019] On the upper surface of the stage 12, a support layer 22 is provided, and the bonding material 114 is placed on this support layer 22. The support layer 22 is made of a rigid material such as metal like stainless steel or aluminum, or ceramic. Further, a plurality of suction holes (not shown) are formed on the surface of the stage 12. These suction holes are fluidly connected to the sheet suction source 26. The sheet suction source 26 applies a negative pressure to the transfer sheet 110 through the suction holes, and is, for example, a suction pump. By driving this sheet suction source 26, the transfer sheet 110 is suction-held on the upper surface of the stage 12.

[0020] The stage 12 is further provided with a clamp 24. The clamp 24 fixes the end portion of the transfer sheet 110 to the stage 12 by pressing the end portion of the transfer sheet 110 toward the upper surface of the stage 12. In the illustrated example, the clamp 24 presses and fixes the right and left ends of the transfer sheet 110 to the stage 12.

[0021] The tool head 14 includes a suction tool 30 that suction-holds the chip 102, and a moving mechanism (not shown) that moves the suction tool 30. By the moving mechanism, the suction tool 30 can move in the horizontal and vertical directions. On the end face of the suction tool 30, a suction hole (not shown) is formed. This suction hole is fluidly connected to the chip suction source 34. The chip suction source 34 applies a negative pressure to the chip 102 through the suction hole, and is, for example, a suction pump. By driving the chip suction source 34, the chip 102 is suction-held by the suction tool 30. Then, by moving the suction tool 30 while suction-holding the chip 102, the chip 102 is transported. The height sensor 36 detects the height of the suction tool 30, and thus the chip 102, and transmits it to the controller 16.

[0022] The tool head 14 further has a vibration source 32. The vibration source 32 applies ultrasonic vibrations to the suction tool 30, and thus to the chip 102 held by the suction tool 30. Such a vibration source 32 has, for example, an ultrasonic vibration element and an AC power supply. The ultrasonic vibration element receives a drive signal that is a voltage signal and generates longitudinal vibrations. This ultrasonic vibration element has, for example, lead zirconate titanate (commonly known as PZT) that vibrates upon receiving an AC voltage, and is a bolt-clamped Langevin type vibrator (commonly known as BLT or BL vibrator) in which the PZT is sandwiched between metal blocks and bolted with bolts to apply clamping pressure. The controller 16 described later drives the vibration source 32 to apply ultrasonic vibrations to the chip 102 after grounding the chip 102 to the transfer sheet 110. Then, due to this ultrasonic vibration, the bonding material 114 is ultrasonically bonded to the chip 102.

[0023] The controller 16 controls the operations of each part of the bonded body manufacturing apparatus 10. For example, the controller 16 controls the movement of the suction tool 30, the ON / OFF of the suction sources 26, 34, the ON / OFF of the vibration source 32, etc. Such a controller 16 is physically a computer having a processor 40 and a memory 42. In FIG. 1, the controller 16 is illustrated as a single computer, but the controller 16 may be configured by combining a plurality of physically separated computers.

[0024] Next, the manufacturing process of the bonded body 100 by such a bonded body manufacturing apparatus 10 will be described. FIG. 2 is a schematic diagram showing the manufacturing process of the bonded body 100, and FIG. 3 is a flowchart showing the manufacturing process. When manufacturing the bonded body 100 by transferring the bonding material 114 to the chip 102, first, the transfer sheet 110 is set on the stage 12 (S10). Then, suction of the transfer sheet 110 by the sheet suction source 26 is started (S12).

[0025] The controller 16 causes the chip 102 to be sucked and held by the suction tool 30, and moves the suction tool 30 above the transfer area of the transfer sheet 110. Then, the chip 102 is gradually lowered toward the transfer sheet 110 together with the suction tool 30 (S14). As a result of the lowering, when the chip 102 contacts the transfer sheet 110 (Yes in S16), the controller 16 presses the chip 102 and presses it against the bonding material 114 (S18). Further, in this state, the controller 16 drives the vibration source 32 to apply ultrasonic vibration to the chip 102 (S18). The upper part of FIG. 2 shows this state. By applying ultrasonic vibration to the chip 102, the bonding material 114 is ultrasonically bonded to the chip 102 and thus transferred.

[0026] If the bonding material 114 is bonded to the chip 102, subsequently, the controller 16 raises the suction tool 30 and moves the chip 102 (S22). At this time, the controller 16 switches the suction and suction release of the transfer sheet 110 by the sheet suction source 26 in conjunction with the movement of the suction tool 30 (S20 to S26). This will be described in comparison with the prior art.

[0027] Conventionally, the bonding material 114 has often been bonded (i.e., transferred) using heat and pressure rather than ultrasonic waves. That is, as shown in the upper part of FIG. 6, while the chip 102 is in contact with the bonding material 114, the chip 102 is heated and pressed. As a result, the bonding material 114 is thermally eutectically bonded to the chip 102. After bonding, the chip 102 was raised while the transfer sheet 110 was being sucked by the stage 12.

[0028] However, in the case of thermal eutectic bonding, as shown in the lower part of FIG. 6, due to the influence of heat, a round shape (fillet) in which the corners of the bonding material 114 bonded to the chip 102 are rounded and chipped is likely to occur. Such a round shape causes defects in the subsequent processes of semiconductor manufacturing.

[0029] Therefore, it is conceivable to join the bonding material 114 by ultrasonic bonding instead of thermocompression bonding. According to ultrasonic bonding, the above-described round shape can be effectively prevented. However, since the bonding force by ultrasonic bonding is weak, the bonding material 114 is relatively easily peeled off from the chip 102. Therefore, when the chip 102 is simply lifted with the transfer sheet 110 sucked to the stage 12 after bonding, as shown in FIG. 7, some of the bonding material 114 remains on the release sheet 112, and the bonding material 114 may not be properly transferred to the chip 102.

[0030] Therefore, in this example, in order to prevent chipping of the bonding material 114, the suction of the transfer sheet 110 by the sheet suction source 26 is released at least in part of the rising process of the chip 102. Specifically, after the bonding material 114 is ultrasonically bonded to the chip 102, the controller 16 stops the ultrasonic vibration and releases the suction of the transfer sheet 110 by the sheet suction source 26 (S20). Then, as shown in the middle row of FIG. 2, the controller 16 raises the chip 102 together with the suction tool 30 while the suction of the transfer sheet 110 is released (S22). By releasing the suction force, the release sheet 112 easily lifts. As a result, as shown in the middle row of FIG. 2, the release sheet 112 is pulled upward together with the bonding material 114 without being forcibly peeled off from the bonding material 114.

[0031] In this state, when the chip 102 is further raised, the release sheet 112 peels off from the bonding material 114. Since this peeling gradually occurs from the end of the bonding material 114, an excessive force is less likely to be applied to the bonding material 114, and chipping of the bonding material 114 is less likely to occur.

[0032] Thereafter, when the chip 102 reaches a pre-defined restart height Hd (Yes in S24), the controller 16 resumes the suction of the transfer sheet 110 by the sheet suction source 26 (S26). Along with the resumption of suction, as shown in the lower part of FIG. 2, the transfer sheet 110 is drawn towards the stage 12. As a result, the release sheet 112 peels off from the bonding material 114. Here, at the timing of resuming suction, the peeling of the release sheet 112 starts at the end of the bonding material 114. Therefore, even if the suction is resumed and the peeling of the release sheet 112 progresses, it is difficult for a load to be generated on the bonding material 114, and chipping of the bonding material 114 is less likely to occur. As a result, the bonding material 114 can be favorably transferred onto the chip 102.

[0033] Thereafter, the controller 16 drives the tool head 14 to convey the transferred chip to a predetermined position. If there is a next chip 102 to be transferred, the controller 16 causes the chip held by the suction tool 30 to be exchanged (S30), and then repeats the processes after step S14. On the other hand, if the transfer of all the chips 102 is completed, the process ends.

[0034] As is clear from the above description, according to this example, by temporarily releasing the suction of the transfer sheet 110 during the rising process of the chip 102, chipping of the bonding material 114 can be prevented, and the bonding material 114 can be favorably transferred onto the chip 102. Further, since the bonding material 114 is bonded to the chip 102 by ultrasonic bonding, it is possible to effectively prevent the round shape at the corner of the bonding material 114.

[0035] Note that the restart height Hd may be determined in advance by experiments or simulations. Such restart height Hd may always be a fixed value or a variable value that changes according to conditions. For example, the restart height Hd may be changed according to at least one of the type of the transfer sheet 110 and the type of the chip 102. For example, the larger the size of the chip 102, the higher the restart height Hd may be set. Also, the restart height Hd may be changed according to the difference in the thickness and material of the transfer sheet 110. Further, the restart height Hd may be changed according to the position within the transfer sheet 110 of the transfer area transferred to the chip 102. For example, the closer the transfer area is to the restraint position by the clamp 24, that is, the closer to the end of the transfer sheet 110, the lower the restart height Hd may be set.

[0036] Furthermore, the restart height Hd may be changed according to the most recent transfer quality. That is, as shown in FIG. 3, usually, the transfer process of the bonding material 114 is sequentially executed for a plurality of chips 102. The controller 16 may monitor the transfer quality of the processed chip 102 periodically or randomly, and change the restart height Hd in the subsequent transfer process according to the quality result. For example, when a predetermined height H1 is set as the restart height Hd (i.e., Hd = H1) and a chip of the bonding material 114 occurs after transfer, the controller 16 increases the current restart height Hd by a predetermined adjustment amount ΔH in the subsequent transfer process, and sets Hd = H1 + ΔH. If a chip of the bonding material 114 still occurs when the transfer process is executed with this new restart height Hd = H1 + ΔH, then this time, the restart height Hd is decreased by the adjustment amount ΔH from the height before the increase, and Hd = H1 - ΔH. Thereafter, the optimal restart height Hd may be searched while gradually increasing the adjustment amount ΔH until no chip of the bonding material 114 occurs. With such a configuration, even if the behavior of the peeling of the release sheet 112 changes due to temperature, humidity, etc., the bonding material 114 can be transferred appropriately.

[0037] Furthermore, when raising the suction tool 30, the chip 102 may be tilted together with the suction tool 30. For example, as shown in FIG. 4, a swing mechanism 48 may be provided to swing the suction tool 30 about a swing axis 46 (see FIG. 2) extending in the horizontal direction. Then, during the process of raising the chip 102 or after the raising is completed, the chip 102 may be tilted together with the suction tool 30. With such a configuration, the release sheet 112 can be peeled off more smoothly, so that chipping of the bonding material 114 can be more effectively prevented.

[0038] Also, the configurations described so far are merely examples, and other configurations may be appropriately changed as long as they include the configuration described in claim 1. For example, in the previous description, the suction of the transfer sheet 110 is resumed according to the height of the chip 102. However, the timing of resuming suction may be determined based on other parameters. For example, a load sensor for detecting the load acting on the suction tool 30 may be provided on the tool head 14, and the timing of resuming suction may be determined based on the detected load detected by this load sensor. For example, it is presumed that when the peeling of the release sheet 112 starts during the process of raising the chip 102, the load acting on the suction tool 30 rapidly decreases. Therefore, during the process of raising the chip 102, the suction of the transfer sheet 110 may be resumed at the timing when the load suddenly changes.

[0039] In the previous description, only one suction system for the transfer sheet 110 has been described, but a plurality of suction systems may be provided. For example, as shown in the upper part of FIG. 5, the stage 12 may have a plurality of suction paths 50a to 50f for each area. In this case, a plurality of switching valves 52a to 52f for switching the communication state between the plurality of suction paths 50a to 50f and the sheet suction source 26 are provided. The controller 16 may switch the opening / closing of the switching valves 52a to 52f according to the situation of the transfer process. For example, consider the case of transferring the bonding material 114 in a certain area Ac to the chip 102. In this case, when the chip 102 is lifted after the transfer is completed, the valves 52b to 52d corresponding to the area Ac and its peripheral areas Ab and Ad are closed, and the valves 52a and 52f corresponding to the other areas Aa, Ae, and Af may be opened.

[0040] With such a configuration, only the areas Ab to Ad within a certain range from the transfer area are released from suction, and the sheet suction in the other areas Aa, Ae, and Af continues. As a result, the bonding material 114 can be lifted under the same conditions in any area.

[0041] That is, when the suction of the entire transfer sheet 110 is released, as shown in the lower part of FIG. 5, depending on the distance from the bonding material 114 to the clamp 24, the inclination of the release sheet 112 that is lifted together with the bonding material 114, and thus the mode of peeling of the release sheet 112 from the bonding material 114, will be different. On the other hand, as described above, when the suction of the transfer sheet 110 is partially released, the sheet suction position becomes the sheet restraint position. Therefore, when the suction of the transfer sheet 110 is partially released, the distance from the transfer area to the sheet restraint position can always be made constant. As a result, the inclination of the release sheet 112 that is lifted together with the bonding material 114, and thus the peeling mode of the release sheet 112, can always be made constant.

[0042] Also, heretofore, if the suction and suction release of the transfer sheet 110 are switched in conjunction with the movement of the suction tool 30, the switching timing of the suction state may be changed as appropriate. For example, in the above description, the suction of the transfer sheet 110 is released prior to the ascent of the chip 102. However, the suction of the transfer sheet 110 may be released after the chip 102 starts to ascend. Further, the bonding material 114 may be bonded to the chip 102 by other bonding methods in addition to ultrasonic bonding. For example, if the problem of the round shape can be avoided, the bonding material 114 may be thermocompression bonded to the chip 102.

[0043] Furthermore, heretofore, it has been described that the suction tool 30 moves relative to the transfer sheet 110 placed on the stage 12. The suction tool 30 only needs to move relative to the transfer sheet 110. For example, the stage 12 may be configured to move up and down relative to the suction tool 30.

[0044] Furthermore, in conjunction with the separation of the suction tool 30 from the release sheet 112, instead of the suction force applied to the transfer sheet 110, the tension applied to the transfer sheet 110 may be changed. For example, in conjunction with the separation of the suction tool 30 from the release sheet 112, the tension of the transfer sheet 110 may be adjusted by changing the holding force of the clamp 24 and changing the clamp position.

Description of Reference Numerals

[0045] 10 Bonding body manufacturing apparatus, 12 Stage, 14 Tool head, 16 Controller, 22 Support layer, 24 Clamp, 26 Sheet suction source, 30 Suction tool, 32 Vibration source, 34 Chip suction source, 36 Height sensor, 40 Processor, 42 Memory, 46 Oscillation axis, 48 Oscillation mechanism, 100 Bonding body, 102 Chip, 110 Transfer sheet, 112 Release sheet, 114 Bonding material, 115 Notch, Hd Resume height.

Claims

1. A transfer sheet on which a release sheet and an adhesive are laminated is placed, a stage that sucks and holds the transfer sheet, a tool head having a tool for holding a chip, a controller, and is provided with, and the controller moves the tool relative to the transfer sheet, grounds the held chip to the adhesive to join it, and then separates it from the release sheet, adjusts the suction force of the transfer sheet by the stage or the tension of the transfer sheet in conjunction with the separation of the tool, and is configured as such. A bonding body manufacturing apparatus characterized by this.

2. The bonding body manufacturing apparatus according to claim 1, wherein the controller is configured to raise the tool together with the chip in a state where the suction of the transfer sheet by the stage is released after the tool has grounded to the adhesive, and then resume the suction of the transfer sheet. A bonding body manufacturing apparatus characterized by this.

3. The bonding body manufacturing apparatus according to claim 2, wherein the controller resumes the suction by the stage at the timing when the chip reaches a specified resumption height. A bonding body manufacturing apparatus characterized by this.

4. The bonding body manufacturing apparatus according to claim 3, wherein the resumption height is a variable value that changes according to at least one of the type of the chip and the position of the transfer area transferred to the chip within the transfer sheet. A bonding body manufacturing apparatus characterized by this.

5. The bonding body manufacturing apparatus according to any one of claims 1 to 4, wherein the stage can partially switch the suction state of the transfer sheet, and the controller is configured to release the suction of the transfer sheet only within a certain range from the transfer area transferred to the chip after bonding of the adhesive. A bonding body manufacturing apparatus characterized by this.

6. The bonding body manufacturing apparatus according to any one of claims 1 to 4, wherein the tool head has a vibration source that applies ultrasonic vibration to the chip, and the controller is further configured to apply ultrasonic vibration to the chip at the timing when the chip is pressed against the adhesive. A bonding body manufacturing apparatus characterized by this.

7. A method for manufacturing a bonded body, sucking and holding a transfer sheet on which a release sheet and an adhesive are laminated with a stage, By moving a tool holding the chip so as to press the chip against the bonding material, the bonding material is bonded to the chip. The suction and suction release of the transfer sheet by the stage are switched in conjunction with the movement of the tool. A method for manufacturing a bonded body, characterized by the above.

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