Method for repairing join

Abstract

To provide a technique of allowing formation of an excellent joining state between joining targets even if a part which is not joined can be generated in a joining process of joining targets such as semiconductor wafers to each other.SOLUTION: A method for repairing a join repairs a joining state of a part which is not joined by applying a laser beam to that part when a part which is not joined is generated in at least a part of a joining target site in a joining process of joining two joining targets in the joining target site set in faces opposed to each other of the two joining targets.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a joining technique using laser light. [Background technology]

[0002] There are semiconductor device manufacturing technologies that include a process for bonding two semiconductor wafers (hereinafter referred to as a "bonding process"). For example, Patent Document 1 describes a technology in which two semiconductor wafers are stacked on top of each other, pressure is applied from the back side of one of the wafers with gas or liquid, and the back side of the other wafer receives pressure to sandwich the two semiconductor wafers, and in this state, laser light is irradiated onto the opposing surfaces of the wafers to bond them together.

[0003] In recent years, such bonding processes have been used in semiconductor device manufacturing technology when sealing sensors (accelerometers, gyro sensors, etc.) and micromachines (actuators, etc.) within devices, and when manufacturing semiconductor devices with a three-dimensional structure in which chips are stacked. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent application No. 2022-92779 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, in the above bonding process, as described in Patent Document 1, when the semiconductor wafers are sandwiched in a stacked state, a holding part may be required to hold the semiconductor wafer. In that case, the part of the semiconductor wafer held by the holding part cannot be irradiated with laser light even if bonding is required at that part, and that part becomes an unbonded part. If such an unbonded part occurs, there may be problems such as the part being wasted, or problems such as adverse effects on processing and equipment in subsequent steps (such as a cutting process) (adverse effects due to flapping or peeling of the semiconductor wafer).

[0006] Even if the part held by the holding part can be irradiated with laser light by some method, the part held by the holding part cannot be applied with appropriate pressure in the previous process (the process of clamping the semiconductor wafer), and as a result, the part may become poorly bonded and may become unbonded. This problem can also occur when the whole semiconductor wafer is heated while being clamped to bond it. Specifically, when the above-mentioned holding part is necessary, the part held by the holding part may have a similar problem due to a lack of pressure required for clamping even when bonding is required at that part.

[0007] Therefore, an object of the present invention is to provide a technique that makes it possible to form a good bond between objects to be bonded, such as semiconductor wafers, even if unbonded portions may occur in a bonding process between the objects to be bonded. [Means for solving the problem]

[0008] The bond repair method of the present invention is a method for repairing a bond at an unbonded portion by irradiating a laser beam to a bonding target portion during a bonding process in which two objects to be bonded are bonded at a bonding target portion set on their opposing surfaces, in which an unbonded portion occurs in at least a part of the bonding target portion.

[0009] According to the above-described bond repair method, the use of laser light makes it possible to limit the heating area to the unbonded portion, and as a result, it is possible to repair the bonded state of the unbonded portion while preventing the adverse effects of heat and light from being exerted on portions other than the unbonded portion. Effect of the Invention

[0010] According to the present invention, even if an unjoined portion may occur in a joining process, it is possible to form a good joint between the objects to be joined. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2A is a cross-sectional view conceptually illustrating an example of two objects to be joined in a joining process, and FIG. 2B is a plan view illustrating the two objects to be joined with one of the objects removed. [Diagram 2] 1A and 1B are conceptual diagrams showing an example of a bonding apparatus used in a bonding process, showing (A) a state in which the second stage is raised, and (B) a state in which the second stage is lowered. [Diagram 3] FIG. 13 is a conceptual diagram showing a state in which an unwelded portion occurs in a welding target portion. [Figure 4] FIG. 2A is a conceptual diagram showing an example of a bond repair device used in a bond repair method according to an embodiment, and FIG. 2B is a plan view showing an example of a first support part used in the embodiment. [Diagram 5] FIG. 13 is a plan view conceptually illustrating (A) the arrangement of the objects to be joined on a support mechanism provided in the bond repair device, and (B) the arrangement of the objects to be joined when rotated in a circumferential direction. [Figure 6] 1A and 1B are conceptual diagrams showing a detour portion and a linear portion that are reset as a joining target portion to avoid inclusions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [1] Bonding process [1-1] Joining target 1(A) and 1(B) are a cross-sectional view and a plan view conceptually showing an example of two objects to be joined 101 and 102 to be joined in a bonding process. The objects to be joined 101 and 102 are base materials constituted by substrates such as semiconductor wafers. FIG. 1(A) is a cross-sectional view taken along line IA-IA shown in FIG. 1(B). FIG. 1(B) is a plan view showing the two objects to be joined 101 and 102 excluding one of the objects to be joined, 102.

[0013] In the example of FIG. 1(A) and FIG. 1(B), the joining target 101 includes a plurality of device regions Rd that are to be divided into individual pieces by cutting along cutting lines Ct. Each device region Rd becomes a base portion of a device after being divided into individual pieces. In addition, each device region Rd is provided with a recess 103 for forming a cavity within the device. Here, the cavity is an enclosed space for sealing an element 104 that performs the function of the device. The element 104 is a sensor (such as an acceleration sensor or a gyro sensor), a micromachine (such as an actuator), an electronic circuit, etc.

[0014] After the elements 104 are placed in the recesses 103 of each device region Rd in the joining target 101, the joining target 102 is joined to the joining target 101 in a state in which all of the recesses 103 are blocked. As a result, cavities are formed in each device region Rd, and the elements 104 are sealed in the cavities. In addition, the joining target 102 is cut into individual pieces together with the joining target 101 by cutting the joining target 101 along the cutting line Ct, thereby becoming the lid of the device.

[0015] The bonding of the bonding objects 101 and 102 at this time is performed at a bonding target portion Pt set in their opposing surfaces 101a and 102a as shown in Fig. 1(A). In the example of Fig. 1(B), in order to bond the entire circumference of the recess 103 in each device region Rd, a rectangular linear portion Pt1 for bonding the circumference of the recess 103 along the cutting line Ct is set as the bonding target portion Pt. The bonding at this linear portion Pt1 is necessary to maintain the cavity as a sealed space in each device obtained by the individualization even after individualization by cutting along the cutting line Ct.

[0016] 1(B), an annular linear portion Pt2 for joining the objects to be joined 101 and 102 around the entire circumference is set as the joining target portion Pt at the peripheral portion Re of the objects to be joined 101 and 102. The joining at the linear portion Pt2 is necessary to prevent fluttering at the peripheral portion Re of the objects to be joined 101 and 102 that may occur during the cutting process (cutting at the cutting line Ct).

[0017] In the bonding process, the bonding target portion Pt having the above-described pattern shape is irradiated with a laser beam to bond the two objects to be bonded 101 and 102. Specifically, the bonding process is performed using a bonding device as described below.

[0018] The shapes of the objects to be joined 101 and 102 and the pattern shape of the joining target portion Pt are not limited to those described above, and can be appropriately changed according to the shape and size of the device to be manufactured, the joining position, line, area, etc. The joining of the objects to be joined 101 and 102 is not limited to being performed by irradiating the joining target portion Pt with laser light, and may be appropriately changed to being performed by heating the entire objects to be joined 101 and 102 with the pressurized area of ​​the objects to be joined 101 and 102 as the joining target portion Pt.

[0019] [1-2]Joining device Fig. 2(A) is a conceptual diagram showing an example of a bonding apparatus used in the bonding process. In the example of Fig. 2(A), the bonding apparatus includes a chamber mechanism 1, a sealing mechanism 2, a pressurizing mechanism 3, a laser light source 4, and a control unit 5. The configuration of each unit will be specifically described below.

[0020] <Chamber mechanism 1> The chamber mechanism 1 has a first chamber component part 11, a second chamber component part 12, and a drive part 13 that drives at least one of them.

[0021] The first chamber component 11 and the second chamber component 12 are components that constitute an enclosed space (hereinafter referred to as "chamber 10") for carrying out the bonding process, and are configured so that the chamber 10 can be selectively formed or opened by moving relatively close to and away from each other in the vertical direction. More specifically, this is as follows.

[0022] The first chamber component 11 is composed of a first cylindrical portion 111 and a first stage 112 that is supported without any gaps inside the first cylindrical portion 111. The first cylindrical portion 111 is disposed with its central axis aligned with the vertical direction, and the first stage 112 is supported horizontally by the first cylindrical portion 111. Here, the first stage 112 is a stage that is transparent to laser light, and is made of, for example, quartz.

[0023] The second chamber component 12 is composed of a second cylindrical portion 121 arranged coaxially with the first cylindrical portion 111 above the first cylindrical portion 111, a second stage 122 supported inside the second cylindrical portion 121 without any gap and movable up and down, and a drive portion 123 for moving the second stage 122 up and down. The upper end of the first cylindrical portion 111 and the lower end of the second cylindrical portion 121 come into contact with each other without any gap, thereby forming a chamber 10 between the first stage 112 and the second stage 122 as shown in Figures 2(A) and 2(B). Note that Figure 2(A) shows a state in which the second stage 122 is raised, and Figure 2(B) shows a state in which the second stage 122 is lowered.

[0024] 2(B), by lowering the second stage 122 to bring it into surface contact with the back surface 102b of the objects to be joined 102, when pressure is applied to the back surface 101b of the objects to be joined 101 from the first stage 112 side (the lower side in the example of FIG. 2(B)) by the pressure mechanism 3 described below, the pressure can be received by the back surface 102b side (the upper side in the example of FIG. 2(B)) of the objects to be joined 102. In this manner, in this bonding apparatus, the second stage 122 can function as a support part that receives pressure on the back surface 102b side of the objects to be joined 102.

[0025] The drive unit 13 is a part that moves at least one of the first chamber component 11 and the second chamber component 12 in the vertical direction, thereby moving these components relatively closer to or farther apart from each other.

[0026] <Sealing mechanism 2> The sealing mechanism 2 is a mechanism that divides the space within the chamber 10 into a plurality of regions (hereinafter referred to as "chamber regions") and seals between adjacent chamber regions (see FIG. 2(B)). Specifically, the sealing mechanism 2 divides the space within the chamber 10 into a first chamber region R1 facing the rear surface 101b of the joining target 101 and a second chamber region R2 adjacent to the first chamber region R1, and seals between these chamber regions. More specifically, it works as follows.

[0027] The seal mechanism 2 is composed of a flange 21 and a holding part 22. Here, the flange 21 is an annular part that protrudes from a position on the inner surface of the first cylindrical part 111 that is above the first stage 112 (i.e., a position close to the second cylindrical part 121) toward the central axis of the first cylindrical part 111, and extends to a position that faces the peripheral parts Re of the objects to be joined 101 and 102 when the objects to be joined 101 and 102 are placed in the chamber 10. The holding part 22 is composed of an annular seal member (such as an O-ring), and is installed on the upper surface of the tip part of the flange 21 so as to support the peripheral parts Re of the objects to be joined 101 and 102 over the entire circumference when the objects to be joined 101 and 102 are placed in the chamber 10.

[0028] According to such a sealing mechanism 2, when the second stage 122 descends and contacts the back surface 102b of the object to be joined 102, the entire periphery Re of the object to be joined 101 and 102 is sandwiched between the second stage 122 and the holder 22. As a result, as shown in Fig. 2(B), the space within the chamber 10 is partitioned into a first chamber region R1 and a second chamber region R2, and the space between these chamber regions is sealed.

[0029] <Pressure mechanism 3> The pressurizing mechanism 3 is a mechanism that applies pressure to the back surface 101b of the joining object 101 by increasing the internal pressure of the first chamber region R1. Specifically, the pressurizing mechanism 3 is a mechanism that uses a gas or liquid as a pressure transmission medium 30, and applies pressure to the back surface 101b of the joining object 101 with the pressure transmission medium 30 in contact with the back surface 101b of the joining object 101. More specifically, it is as follows.

[0030] The pressurizing mechanism 3 can adjust the internal pressure for each chamber region formed by dividing the inside of the chamber 10 with the sealing mechanism 2, can reduce the pressure in each chamber region, and can further pressurize the first chamber region R1 with the pressure transmission medium 30. Pressurization of the first chamber region R1 is achieved by supplying the pressure transmission medium 30 (gas or liquid) to the first chamber region R1 by, for example, a compression pump. Then, the pressurizing mechanism 3 makes the internal pressure of the first chamber region R1 higher than the internal pressure of the second chamber region R2, and uses the difference between the two to apply pressure to the back surface 101b of the joining object 101.

[0031] <Laser light source 4> The laser light source 4 is a part that emits laser light, and is disposed below the first stage 112 that is transparent to the laser light. The laser light source 4 can irradiate the objects to be joined 101 and 102 with laser light via the first stage 112, while scanning the laser light in a horizontal plane along the pattern shape of the joining target portion Pt. Furthermore, the laser light source 4 can focus the laser light on the joining location (position of the joining target portion Pt) of the objects to be joined 101 and 102.

[0032] <Control unit 5> The control unit 5 is composed of a processing device such as a CPU or a microcomputer, and controls various operating units (such as the chamber mechanism 1, the pressurizing mechanism 3, and the laser light source 4) of the bonding apparatus. Specifically, the bonding process is carried out by the control unit 5 performing control along the following flow.

[0033] The control unit 5 first brings the first chamber component 11 and the second chamber component 12 close to each other and combines them to form the chamber 10 (see FIG. 2(A)). Here, the objects to be joined 101 and 102 are placed on the holder 22 before the chamber 10 is formed.

[0034] Next, the control unit 5 controls the pressurizing mechanism 3 to reduce the internal pressure of the entire chamber 10 until the chamber 10 is in a vacuum state. At this time, the peripheral portions Re of the objects to be joined 101 and 102 are not yet sandwiched between the second stage 122 and the holding unit 22, and are therefore in a state of being released from the seal. Therefore, the gas present between the objects to be joined 101 and 102 can be discharged to the outside (into the chamber 10) through between the objects to be joined 101 and 102. Therefore, the internal pressure between the objects to be joined 101 and 102 can also be reduced.

[0035] Thereafter, the control unit 5 lowers the second stage 122 to contact the back surface 102b of the object to be joined 102, thereby sandwiching the entire periphery Re of the objects to be joined 101 and 102 between the second stage 122 and the holding unit 22 (see FIG. 2(B)). As a result, a first chamber region R1 and a second chamber region R2 are formed, and the space between them is sealed.

[0036] In this state, the control unit 5 controls the pressurizing mechanism 3 to increase the internal pressure of the first chamber region R1 while keeping the second chamber region R2 in a vacuum state. As a result, the internal pressure of the first chamber region R1 becomes higher than the internal pressure of the second chamber region R2, and a pressure according to the difference between the internal pressures is applied to the back surface 101b of the bonding object 101. As a result, the bonding objects 101 and 102 are sandwiched between the pressure transmission medium 30 and the second stage 122 (pressurizing step). At this time, by changing the internal pressure of the first chamber region R1, the pressure applied to the back surface 101b of the bonding object 101 can be changed to a desired value. Note that the internal pressure of the first chamber region R1 may be set to a value lower than atmospheric pressure, set to a value approximately equal to atmospheric pressure, or set to a value higher than atmospheric pressure, as long as it is higher than the internal pressure of the second chamber region R2.

[0037] After the pressure mechanism 3 applies pressure to the rear surface 101b of the joining objects 101, the control unit 5 maintains that state and controls the laser light source 4 to irradiate the joining target portions Pt of the joining objects 101 and 102 with laser light. At this time, the control unit 5 scans the laser light in a horizontal plane along the pattern shape of the joining target portions Pt. In this manner, the joining process for joining the two joining objects 101 and 102 is performed by the joining device.

[0038] In addition, the above-mentioned joining device is not limited to one that joins the joining objects 101 and 102 by irradiating laser light to a joining target portion Pt having a pattern shape, but may be appropriately modified to one that joins the joining objects 101 and 102 by heating the entire joining objects 101 and 102, with the pressure area for the joining objects 101 and 102 being the joining target portion Pt.

[0039] [1-3] Occurrence of unjoined parts In the above-mentioned joining device, when the joining process is performed, the entire periphery Re of the joining objects 101 and 102 is sandwiched between the second stage 122 and the holding part 22 (see Fig. 1(B) and Fig. 2(B)). For this reason, as shown in Fig. 3, when the joining target part Pt is irradiated with laser light, the presence of the sealing mechanism 2 including the holding part 22 prevents the laser light from being irradiated to the part (annular linear part Pt2) set on the periphery Re of the joining target part Pt, and as a result, this part becomes an unjoined part Pu. If such an unjoined part Pu occurs, it becomes impossible to suppress fluttering at the periphery Re of the joining objects 101 and 102 that may occur in the cutting process (cutting at the cutting line Ct).

[0040] In addition, not only when the joining process is performed using the above-mentioned joining device, but also when a holding part is required to hold the two joining objects 101 and 102 when they are sandwiched together in a superimposed state, a part of the joining target part Pt may be hidden by the holding part (and the mechanism including it). In that case, the part of the joining target part Pt that is hidden by the holding part cannot be irradiated with laser light, and this part becomes an unjoined part Pu. When such an unjoined part Pu occurs, not only the above-mentioned fluttering problem but also problems such as the part where the unjoined part Pu occurs being wasted and adverse effects (such as peeling) on ​​processing and equipment in subsequent steps may occur.

[0041] Furthermore, even if it were possible to irradiate the laser light to the portion of the welding target part Pt that is hidden by the holding part (and the mechanism including it) in some way, in the previous process (the process of clamping the welding objects 101 and 102), it would be impossible to apply appropriate pressure to the portion held by the holding part, which would result in a poor welding at that portion, resulting in an unwelded part Pu. This problem can also occur when the welding objects 101 and 102 are clamped and then heated as a whole to be bonded, if a holding part as described above is required, because the pressure required for clamping will be insufficient at the portion held by the holding part.

[0042] Therefore, even if an unbonded portion Pu may occur in the bonding process, in order to form a good bonded state between the objects to be bonded 101 and 102, the present inventor proposes a bond repair method for repairing the bonded state at the unbonded portion Pu by irradiating the unbonded portion Pu with a laser beam. The bond repair method will be specifically described below.

[0043] In addition to the above-mentioned reasons, other possible reasons for the occurrence of the unbonded portion Pu include a foreign object being caught between the two objects to be bonded 101 and 102, preventing the objects to be bonded 101 and 102 from coming into close contact with each other, or a temporary insufficient output of the laser light source 4 causing a shortage of power of the laser light required for bonding. A method for repairing the bonded state of the unbonded portion Pu caused by these reasons will be described in the second modified example described later.

[0044] [2] Joint repair method The bond repair method according to the embodiment can be performed using a bond repair device as described below.

[0045] 4(A) is a conceptual diagram showing an example of a bond repair device. The bond repair device includes a support mechanism 6, a laser light source 7, and a control unit 8.

[0046] The support mechanism 6 is a mechanism including a first support part 61 and a second support part 62, and supports the joining objects 101 and 102 after the above-mentioned joining step is performed by sandwiching them from their back surfaces 101b and 102b between the first support part 61 and the second support part 62. The support mechanism 6 supports the joining objects 101 and 102 with the first support part 61 and the second support part 62, and may further have a pressurizing function of sandwiching and pressing them.

[0047] In this embodiment, the first support portion 61 is disposed so as to be located on the laser light incident side (the rear surface 101b side of the object to be joined 101 in the example of FIG. 4(A)) with respect to the objects to be joined 101 and 102. A support portion having a window 61w for passing the laser light from the laser light source 7 is used as the first support portion 61. Specifically, the window 61w is formed in the first support portion 61 so that at least a part of the unjoined portion Pu can be seen through the window 61w when the objects to be joined 101 and 102 are sandwiched between the first support portion 61 and the second support portion 62.

[0048] Fig. 4(B) is a plan view showing an example of the first support part 61 used in the embodiment. Here, Fig. 4(B) shows the first support part 61 that can be used to repair the joined state of the unjoined part Pu when the annular linear part Pt2 of the joining target part Pt shown in Fig. 1(B) becomes an unjoined part Pu (in other words, when the unjoined part Pu occurs on the peripheral parts Re of the two joining objects 101 and 102).

[0049] Specifically, the first support portion 61 is composed of a main body portion 611, an annular portion 612, and a beam portion 613. Here, the main body portion 611 is a portion that contacts a central region of the back surface 101b of the joining object 101 that is on the inner side of the peripheral portion Re (see FIG. 4(A)). The annular portion 612 is a portion that contacts a ring-shaped region of the back surface 101b of the joining object 101 that includes the outer periphery and has a width narrower than the peripheral portion Re (see FIG. 4(A)). The beam portion 613 is a portion that connects the ring-shaped portion 612 to the main body portion 611 at at least one point (see FIG. 4(B)). The region surrounded by the main body portion 611, the annular portion 612, and the beam portion 613 is the window 61w of the first support portion 61. 4(B) shows the first support portion 61 in which an annular portion 612 is connected to a main body portion 611 at four locations by four beam portions 613 arranged at equal intervals around the center point, resulting in four windows 61w. Note that the configuration of the first support portion 61 (shape, number, etc. of the windows 61w) is not limited to that shown in FIG. 4(B) and can be changed as appropriate according to the shape of an unjoined portion Pu generated in a joining target portion Pt, etc.

[0050] The laser light source 7 is a part that emits laser light, and can irradiate the laser light through the window 61w of the first support part 61 toward the objects to be joined 101 and 102 supported by the support mechanism 6. Specifically, the laser light source 7 can irradiate the laser light through the window 61w of the first support part 61 to the unjoined portion Pu seen through the window 61w. The laser light source 7 can also scan the laser light in a horizontal plane along the pattern shape of the unjoined portion Pu (here, the pattern shape of the annular linear portion Pt2). Furthermore, the laser light source 4 can focus the laser light on the joining location (the position of the unjoined portion Pu) between the objects to be joined 101 and 102.

[0051] The control unit 8 is composed of a processing device such as a CPU or a microcomputer, and controls various operating units (support mechanism 6, laser light source 7, etc.) of the bond repair device. Specifically, the bond repair method is carried out by the control unit 8 performing control along the following flow.

[0052] The control unit 8 first supports the objects to be joined 101 and 102 with the support mechanism 6 (supporting step; see FIG. 4(A)). At this time, the objects to be joined 101 and 102 are arranged such that at least a part of the unjoined portion Pu is visible through the window 61w of the first support part 61, as shown in FIG. 5(A). At this time, the control unit 8 may control the support mechanism 6 to clamp the objects to be joined 101 and 102 with the first support part 61 and the second support part 62.

[0053] Thereafter, the control unit 8 controls the laser light source 7 to irradiate the unbonded portion Pu seen through the window 61w of the first support portion 61 with laser light (repair step). At this time, the control unit 8 scans the laser light in a horizontal plane along the pattern shape of the unbonded portion Pu (here, the pattern shape of the annular linear portion Pt2). This causes the bonded state of the portion of the unbonded portion Pu seen through the window 61w of the first support portion 61 to be repaired. In this manner, the bond repair method for repairing the bonded state of the unbonded portion Pu is executed by the bond repair device.

[0054] According to this type of bond repair method, the heating area can be limited to the unbonded portion Pu by using laser light, and as a result, the bonded state of the unbonded portion Pu can be repaired while preventing the adverse effects of heat and light from being exerted on portions other than the unbonded portion Pu.

[0055] Furthermore, according to the first support portion 61, the periphery of the unjoined portion Pu seen through the window 61w can be supported by the edge of the window 61w (the main body portion 611, the annular portion 612, and the beam portion 613), thereby increasing the degree of adhesion between the two objects to be joined 101 and 102 at the unjoined portion Pu. Therefore, by irradiating the unjoined portion Pu seen through the window 61w with laser light, it is possible to restore the joint state of the unjoined portion Pu to a good one.

[0056] [3] Variations [3-1] First modified example In the repair step of the above-mentioned bond repair method, the portion of the unbonded portion Pu visible through the window 61w of the first support portion 61 can be irradiated with laser light, but the portion of the unbonded portion Pu hidden by the beam portion 613 cannot be irradiated with laser light, and the bonded state of that portion cannot be repaired (see Figure 5(A)).

[0057] Therefore, after the repair step is performed, the objects 101 and 102 to be joined may be rearranged by rotating the objects 101 and 102 in the circumferential direction so that the portion of the unjoined portion Pu that was hidden by the beam portion 613 is visible through the window 61w, as shown in Fig. 5(B). Note that in Fig. 5(B), the repaired portion of the unjoined portion Pu is indicated by a thick solid line. Then, the above-mentioned repair step may be performed again on the portion of the unjoined portion Pu that was hidden by the beam portion 613.

[0058] According to this bond repair method, even if the bonded state of all the unbonded parts Pu cannot be repaired by one repair step, it is possible to repair the bonded state of all the unbonded parts Pu by rearranging the bonding objects 101 and 102 and performing the repair step again. Moreover, such re-execution of the repair step can be repeated by rearranging the bonding objects 101 and 102 each time until the bonded state of all the unbonded parts Pu can be repaired.

[0059] Incidentally, the bond repair method of this modified example may be appropriately modified so that, instead of rotating the objects to be joined 101 and 102 circumferentially and repositioning them, the first support portion 61 of the bond repair device is rotated circumferentially (in other words, the objects to be joined 101 and 102 are rotated circumferentially relative to the first support portion 61), thereby enabling the portion of the unjoined portion Pu that was hidden by the beam portion 613 to be seen through the window 61w.

[0060] [3-2] Second variant As described above, possible reasons for the occurrence of the unbonded portion Pu include a foreign object being caught between the two objects to be joined 101 and 102 and preventing the objects to be joined 101 and 102 from coming into close contact with each other, and a temporary insufficient output of the laser light source 4 causing a shortage of power of the laser light required for joining. Meanwhile, with regard to the unbonded portion Pu that may occur for these reasons, unlike the case of the above-mentioned embodiment (i.e., the case where it is clear that the portion of the joining target portion Pt held by the holding portion will become the unbonded portion Pu), at the time of completion of the joining process, it is unclear whether or not the unbonded portion Pu has actually occurred, and even if the unbonded portion Pu has occurred, it is unclear where the unbonded portion Pu has occurred.

[0061] Therefore, in order to make it possible to form a good bonded state between the objects to be joined 101 and 102 even if an unbonded portion Pu may occur for these reasons, the present inventor further proposes the following bond repair method.

[0062] First, an unjoined portion Pu occurring in the joining target portion Pt is identified by inspecting the joining state in the joining target portion Pt after the joining process (identification step). Next, the unjoined portion Pu identified in the identification step is irradiated with a laser beam to repair the joining state in the unjoined portion Pu (repair step).

[0063] As a specific example, consider the case where a joining process is performed using the joining device shown in Figure 2(A), and an unjoined portion Pu occurs in an area where pressurization by the pressure transmission medium 30 is possible (area where laser light can be irradiated; in other words, area other than the part where laser light irradiation is prevented by the presence of the sealing mechanism 2 including the retaining portion 22).

[0064] First, consider a case where the cause of the unbonded portion Pu is insufficient power of the laser beam. In this case, after identifying the unbonded portion Pu in the identifying step, the bonding objects 101 and 102 are clamped together (pressurizing step) using the bonding device (see FIG. 2(A)) used in the bonding process again, and then in the repair step, the unbonded portion Pu is irradiated with laser beam in a state where the insufficient power of the laser beam is eliminated, thereby repairing the bonded state of the unbonded portion Pu.

[0065] Next, consider a case where the unbonded portion Pu is caused by a foreign object (inclusion) sandwiched between the objects to be joined 101 and 102. In this case, in the objects to be joined 101 and 102 after the joining process is performed, a bulge having the position of the inclusion as its apex is generated on the back surface 102b of the object to be joined 102. By observing the back surface 102b of the object to be joined 102 with a camera, such a bulge can be observed as an interference pattern. Therefore, in the identifying step, by observing the back surface 102b of the object to be joined 102 with a camera, a portion of the joining target portion Pt that overlaps with the interference pattern observed by the camera can be identified as the unbonded portion Pu. Also, the center position of the interference pattern can be identified as the position of the inclusion.

[0066] In this case, too, the bonding state of the unbonded portion Pu can be repaired by using again the bonding device (see FIG. 2(A)) used in the bonding process. However, since the cause of the unbonded portion Pu is an inclusion, it cannot be removed, and therefore the bulge with the inclusion as its apex cannot be eliminated. Furthermore, if an inclusion is located on the unbonded portion Pu, it is difficult to improve the bonding state of the unbonded portion Pu even if the unbonded portion Pu caused by the inclusion is directly irradiated with laser light.

[0067] Therefore, before performing the repair step, a pressure greater than the pressure applied to the back surface 101b of the objects to be joined 101 when the objects to be joined 101 and 102 are clamped in the joining process is applied by the pressure transmission medium 30 (pressurizing step). This makes it possible to shrink the bulge as much as possible and increase the contact area of ​​the objects to be joined 101 and 102 around the inclusion.

[0068] Then, in the repair step, the bulge is kept in a state in which it has been shrunk as much as possible by the pressurizing step, while laser light is irradiated while avoiding the location of the inclusion identified in the identification step, thereby repairing the bonded state at the unbonded portion Pu.

[0069] Here, if the inclusion is located in a position displaced from the unjoined portion Pu, the bulge is made as small as possible in the above-mentioned pressurizing step to reduce the effect of the inclusion, and then the unjoined portion Pu can be directly irradiated with laser light to repair the joining state of the unjoined portion Pu.

[0070] On the other hand, when an inclusion is located on the unjoined portion Pu, the laser beam is irradiated to a position shifted from the unjoined portion Pu to avoid the position of the inclusion, and the repair of the joint state at the unjoined portion Pu is complemented by the joining at the shifted position. As an example, as shown in Fig. 6(A), a detour portion Pt3 that detours around the position of the inclusion is reset as the joining target portion Pt, and the detour portion Pt3 is irradiated with a laser beam, thereby complementing the repair of the joint state at the unjoined portion Pu. In Fig. 6(A), the part of the joining target portion Pt where the joining has been completed is indicated by a thick solid line (similar to Fig. 6(B)). As another example, as shown in FIG. 6(B), by resetting another linear portion Pt4 as the joining target portion Pt along a part of the joining target portion Pt that includes the unjoined portion Pu (including a portion where joining has already been completed), and irradiating the linear portion Pt4 with laser light, it is possible to complement the repair of the joining state at the unjoined portion Pu (see FIG. 6(B)).

[0071] The irradiation of laser light onto the unjoined portion Pu in the repair step includes not only cases where the laser light is directly irradiated onto the unjoined portion Pu to repair the joined state of the unjoined portion Pu, but also cases where the laser light is not directly irradiated onto the unjoined portion Pu but it is necessary to avoid inclusions, and the repair of the joined state at the unjoined portion Pu can be complemented by irradiating the laser light at a position shifted from the unjoined portion Pu to avoid the inclusions.

[0072] [3-3] Third variant When the cause of the unbonded portion Pu is a foreign object (inclusion) sandwiched between the objects to be bonded 101 and 102, in the above-described second modified example, as a method for repairing the bonded state of the unbonded portion Pu, a pressurizing step is performed before performing the repair step, thereby shrinking the bulge caused by the inclusion as much as possible and increasing the contact area of ​​the objects to be bonded 101 and 102 around the inclusion. However, instead of or in parallel with the pressurizing step, a pre-processing step such as the following may be performed.

[0073] Specifically, before executing the repair step, the inclusion at the position identified in the identification step is irradiated with a pretreatment laser beam to heat and deform the inclusion, or to sublimate the inclusion by a phenomenon such as ablation (pretreatment step). This makes it possible to reduce the height of the bulge, and as a result, to increase the contact area of ​​the objects to be joined 101 and 102 around the inclusion.

[0074] Furthermore, when the inclusions are heated and deformed with laser light in the pretreatment step, a pressure application step can be performed in parallel to pressurize the heated inclusions with pressure, thereby efficiently deforming them, and as a result, the height of the bulge can be reduced.

[0075] In addition, when the inclusions are sublimated by laser light in the pretreatment step, the gas generated by the sublimation can be pushed into the cavity by pressure by performing the pressurization step in parallel, and as a result, the bulge can be eliminated. If the bulge can be eliminated, it becomes possible to irradiate the unbonded part Pu with laser light directly in the repair step without avoiding the inclusions.

[0076] The above-mentioned embodiments and the description of the modifications should be considered as illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims, not by the above-mentioned embodiments and modifications. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope of the claims.

[0077] Furthermore, from the above-mentioned embodiment and modified examples, each step constituting the bond repair method may be extracted individually as a subject of the invention, or a bond repair device used in the bond repair method and each part of the bond repair device (such as the first support part 61) may be extracted individually. Furthermore, a combination of these with a part of a bonding process or a bonding device may be extracted as a subject of the invention. [Explanation of symbols]

[0078] 1. Chamber mechanism 2. Sealing mechanism 3. Pressurizing mechanism 4 Laser light source 5. Control section 6 Support mechanism 7 Laser light source 8. Control Unit 10. Chamber 11 First chamber component 12 Second chamber component 13 Drive unit 21 Flange 22 Holding part 30 Pressure transmission medium 61 1st support part 61w Window 62 Second support part Ct cutting line Pt joint target area Pu unbonded part R1 First chamber area R2 Second chamber area Rd Device Region Re Periphery 101, 102 Joint target 101a, 102a Opposite surface 101b, 102b back 103 Depression 104 Elements 111 First cylindrical part 112 1st Stage 121 Second cylindrical section 122 Second Stage 123 Drive unit 611 Main body 612 Circular section 613 Beam section Pt1, Pt2, Pt4 linear part Pt3 detour section

Claims

1. In a joining process in which two objects to be joined are joined at a joining target area set within their opposing surfaces, if an unjoined area occurs in at least a part of the joining target area, a joining repair method is provided in which the joining state at the unjoined area is repaired by irradiating the unjoined area with laser light. The support step involves supporting the two objects to be joined by sandwiching them between a first support portion and a second support portion from their back sides, wherein the first support portion is a support portion that allows at least a part of the unjoined portion to be seen through a window for passing laser light, After the support step, a repair step is performed to repair the bonding state at the unbonded portion by irradiating the unbonded portion with laser light through the window, Includes, A joint repair method in which, when the unjointed portion occurs at the periphery of the two objects to be joined, the first support portion includes a main body portion that contacts the central region of the back surface inward from the periphery, an annular portion that contacts the annular region along the outer edge of the back surface, and a beam portion that connects the annular portion to the main body portion, wherein the region enclosed by these portions is the window.

2. The joint repair method according to claim 1, wherein after performing the repair step, the two joint targets are rotated circumferentially relative to the first support so that the portion of the unjointed area that was hidden by the beam is visible through the window, and then the repair step is performed again on that portion.

3. A bonding repair method in which two objects to be bonded are bonded at a bonding target portion set on their opposing surfaces, wherein if an unbonded portion occurs in at least a part of the bonding target portion, the bonding state at the unbonded portion is repaired by irradiating the unbonded portion with laser light. A pressurizing step in which pressure is applied to the back surface of one of the two objects to be joined, with a gas or liquid acting as a pressure transmission medium in direct contact, and the pressure is received by a support on the back surface of the other object to be joined, thereby clamping the two objects to be joined together. A repair step in which, while pressing the two objects to be joined together by the pressurization step, laser light is irradiated onto the unjointed portion from the back side of one of the objects to be joined, thereby repairing the joining state at the unjointed portion, A method of repairing a bond, including a method of joining and repairing a joint.

4. The aforementioned pressurizing step is also used in the bonding process, The bonding repair method according to claim 3, wherein in the pressurizing step performed when repairing the unbonded portion, a pressure greater than the pressure applied in the pressurizing step performed before the repair is applied to the back surface of one of the objects to be bonded, using a gas or liquid pressure transmission medium.

5. A selection step to identify the unjoined portion in the target joint by inspecting the joining state at the target joint after the joining process, A repair step in which the bonding state at the unbonded portion identified in the specified step is restored by irradiating the unbonded portion with laser light, A joint repair method according to any one of claims 1 to 4, including the following:

6. A bonding repair method in which two objects to be bonded are bonded at a bonding target portion set on their opposing surfaces, wherein if an unbonded portion occurs in at least a part of the bonding target portion, the bonding state at the unbonded portion is repaired by irradiating the unbonded portion with laser light. A selection step to identify the unjoined portion in the target joint by inspecting the joining state at the target joint after the joining process, A repair step in which the bonding state at the unbonded portion identified in the specified step is restored by irradiating the unbonded portion with laser light, Includes, In the aforementioned identification step, the unjointed portion is identified, and if the cause of the unjointed portion is an inclusion, the location of the inclusion is identified. A bonding repair method comprising the repair step of repairing the bonding state at the unbonded portion by irradiating laser light while avoiding the location of the inclusion identified in the identification step.

7. A bonding repair method in which two objects to be bonded are bonded at a bonding target portion set on their opposing surfaces, wherein if an unbonded portion occurs in at least a part of the bonding target portion, the bonding state at the unbonded portion is repaired by irradiating the unbonded portion with laser light. The identification step involves inspecting the bonding state at the target bonding portion after the bonding process to identify the unbonded portion that occurred at the target bonding portion, and, if the cause of the unbonded portion is an inclusion, to identify the location of the inclusion. A pre-treatment step in which the inclusion at the location identified in the specified step is irradiated with laser light to deform or sublimate the inclusion, After the pre-processing step, a repair step is performed to repair the bonding state at the unbonded portion identified in the specific step by irradiating it with laser light, A method of repairing a bond, including a method of joining and repairing a joint.

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