Pre-solder forming method and pre-solder forming apparatus

Abstract

The preliminary solder forming method is a method for forming preliminary solder on an aluminum electrode formed of aluminum. The preparation solder forming method includes: a disposing step of disposing solder on an aluminum electrode; and a bonding step in which the solder is bonded to the aluminum electrode by melting and solidifying the solder using a laser. In the joining step, the laser light is irradiated such that the energy of the laser light irradiated to the aluminum electrode is greater than the energy of the laser light irradiated to the solder.

Description

Technical Field

[0001] One aspect of the present invention relates to a method and apparatus for forming a pre-solder. Background Technology

[0002] For example, Patent Document 1 describes a method in which solder is bonded to an LSI chip by irradiating it with a laser.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 9-237963 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] If the method described above is used to form a pre-solder on an aluminum electrode, there is a possibility that the solder cannot be properly bonded due to the poor wettability of the aluminum electrode relative to the solder.

[0008] Therefore, one objective of the present invention is to provide a method and apparatus for forming a pre-solder that can effectively form a pre-solder on an aluminum electrode.

[0009] Technical means to solve the problem

[0010] One aspect of the present invention is a method for forming a pre-solder, [1] “A method for forming a pre-solder, which is a method for forming a pre-solder on an aluminum electrode formed of aluminum, comprising: a placement step in which solder is placed on the aluminum electrode; and a bonding step in which the solder is bonded to the aluminum electrode by melting and solidifying the solder using a laser, wherein the laser is irradiated in such a way that the energy of the laser irradiating the aluminum electrode is greater than the energy of the laser irradiating the solder.”

[0011] In the bonding step of this pre-solder forming method, the laser is irradiated with an energy greater than that of the laser irradiating the solder. This allows the aluminum electrode to be heated before the solder, ensuring the aluminum electrode is in a heated state at the point when the solder melts. As a result, the aluminum electrode can be easily wetted by the solder at the bonding site, thus enabling good bonding of the solder to the aluminum electrode. Therefore, according to this pre-solder forming method, pre-solder can be well formed on the aluminum electrode. Furthermore, "the energy of the laser irradiating the aluminum electrode is greater than that of the laser irradiating the solder" includes the case where the energy of the laser irradiating the solder is zero (i.e., the laser does not irradiate the solder).

[0012] One aspect of the pre-solder forming method of the present invention may also be, [2] "as described in [1], wherein, in the above-mentioned bonding process, all of the above-mentioned laser is irradiated onto the above-mentioned aluminum electrode." In this case, the aluminum electrode can be heated stably, and the yield can be improved.

[0013] One aspect of the pre-solder forming method of the present invention may also be, [3] "as described in [1], wherein, in the above-mentioned bonding process, a portion of the laser is irradiated onto the aluminum electrode, and the remainder of the laser is irradiated onto the solder." In this case, the aluminum electrode and the solder can be heated evenly, and the process can be shortened.

[0014] One aspect of the pre-solder forming method of the present invention may also be, [4] "the pre-solder forming method as described in any one of [1] to [3], wherein, in the above-mentioned bonding process, the laser is irradiated such that the center of the laser is located outside the solder." In this case, the laser can be easily irradiated in such a way that the energy of the laser irradiating the aluminum electrode is greater than the energy of the laser irradiating the solder.

[0015] One aspect of the pre-solder forming method of the present invention may also be, [5] "the pre-solder forming method as described in any one of [1] to [4], wherein, in the above-mentioned bonding process, the laser is irradiated in such a way that the area of ​​the laser irradiating the aluminum electrode is greater than the area of ​​the laser irradiating the solder." In this case, the laser can be easily irradiated in such a way that the energy of the laser irradiating the aluminum electrode is greater than the energy of the laser irradiating the solder.

[0016] One aspect of the pre-solder forming method of the present invention may also be, [6] "the pre-solder forming method as described in any one of [1] to [5], wherein, in the above-mentioned bonding process, the laser is irradiated while the pressure-adhesion member disposed on the opposite side of the aluminum electrode relative to the solder is in contact with the solder." In this case, the solder can be further and better bonded to the aluminum electrode.

[0017] One aspect of the pre-solder forming method of the present invention may also be, [7] "as described in [6], wherein the aforementioned bonding member is transmissive to the aforementioned laser, and in the aforementioned bonding process, the laser is irradiated onto the surface of the aluminum electrode on which the aforementioned solder is disposed via the aforementioned bonding member." In this case, the laser can be irradiated in the area overlapping with the bonding member.

[0018] One aspect of the pre-solder forming method of the present invention may also be, [8] "the pre-solder forming method as described in any one of [1] to [7], wherein, in the above-mentioned bonding process, the solder is irradiated with the laser while being surrounded by the surrounding member when viewed from the irradiation direction of the laser." In this case, the movement of the molten solder can be suppressed by the surrounding member, and the solder can be further and better bonded to the aluminum electrode.

[0019] One aspect of the pre-solder forming method of the present invention may also be, [9] "the pre-solder forming method as described in [8], wherein the aforementioned surrounding member is formed of epoxy glass or silicone." In this case, the thermal conductivity of the surrounding member can be reduced, and heat escape from the solder through the surrounding member can be suppressed. In addition, the heat resistance of the surrounding member can be improved, and damage to the surrounding member due to the temperature during processing can be suppressed.

[0020] One aspect of the pre-solder forming method of the present invention may also be,

[10] "the pre-solder forming method as described in [8] or [9], wherein the surrounding member is transmissive to the laser." In this case, since it is not necessary to avoid irradiating the laser from the surrounding member, the laser irradiation can be simplified.

[0021] One aspect of the pre-solder forming method of the present invention may also be,

[11] "the pre-solder forming method described in any one of [1] to

[10] , wherein, in the above-mentioned bonding process, a pressing member disposed on the opposite side of the aluminum electrode relative to the solder is in contact with the solder, and the solder is surrounded by a surrounding member when viewed from the irradiation direction of the laser, wherein the pressing member and the surrounding member are integrally formed." In this case, by using the pressing member and the surrounding member, the solder can be further and better bonded to the aluminum electrode. In addition, since the pressing member and the surrounding member are integrally formed, the number of members can be reduced and the operation time can be shortened.

[0022] One aspect of the pre-solder forming method of the present invention may also be,

[12] "the pre-solder forming method as described in any one of [1] to

[11] , wherein, in the above-mentioned bonding process, the surface of the aluminum electrode on which the solder is disposed is irradiated with the laser." In this case, the solder can be reliably bonded to the aluminum electrode.

[0023] One aspect of the pre-solder forming method of the present invention may also be,

[13] "the pre-solder forming method as described in any one of [1] to

[11] , wherein, in the above-mentioned bonding process, the surface opposite to the surface of the aluminum electrode on which the solder is disposed is irradiated with the laser." In this case, since it is not necessary to avoid irradiating the solder with the laser, the irradiation of the laser can be simplified.

[0024] One aspect of the pre-solder forming method of the present invention may also be,

[14] "the pre-solder forming method as described in any one of [1] to

[13] , wherein, in the above-mentioned configuration step, the solder containing flux is configured on the aluminum electrode." According to this pre-solder forming method, even solder containing flux can be well bonded to the aluminum electrode.

[0025] One aspect of the present invention is a pre-solder forming apparatus,

[15] "A pre-solder forming apparatus for forming pre-solder on an aluminum electrode made of aluminum, comprising: an irradiation unit that irradiates a laser; and a control unit that controls the irradiation unit to irradiate the laser in such a way that the energy of the laser irradiating the aluminum electrode is greater than the energy of the laser irradiating the solder disposed on the aluminum electrode, thereby melting and solidifying the solder and thereby bonding the solder to the aluminum electrode." According to this pre-solder forming apparatus, for the above reasons, the solder can be well bonded to the aluminum electrode.

[0026] The effects of the invention

[0027] According to one aspect of the present invention, a method and apparatus for forming a pre-solder can be provided that can effectively bond solder to an aluminum electrode. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the pre-solder forming apparatus.

[0029] Figure 2 It is a cross-sectional view used to illustrate the method of forming pre-solder.

[0030] Figure 3 This is a flowchart used to illustrate the operation of the pre-solder forming apparatus.

[0031] Figure 4 (a) and (b) are diagrams used to illustrate the position of the laser irradiation.

[0032] Figure 5 This is a cross-sectional view used to illustrate the pre-solder formation method of the comparative example.

[0033] Figure 6 This is a cross-sectional view used to illustrate the pre-solder formation method of the first modified example.

[0034] Figure 7 It is a cross-sectional view showing the state where solder is placed on flux.

[0035] Figure 8 This is a cross-sectional view used to illustrate the pre-solder formation method of the second variation.

[0036] Figure 9 This is a cross-sectional view used to illustrate the pre-solder formation method of the third variation.

[0037] Figure 10 This is a cross-sectional view used to illustrate the pre-solder formation method of the fourth variation.

[0038] Figure 11 This is a schematic diagram of the pre-solder forming apparatus for the fifth variation.

[0039] Figure 12 This is a flowchart illustrating the operation of the pre-solder forming apparatus in the fifth variation. Detailed Implementation

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements are referred to by the same reference numerals, and repeated descriptions are omitted.

[0041] like Figure 1 As shown, the pre-solder forming apparatus 1 includes a frame 2, an irradiation head 3 (irradiation unit), a camera 4, and a control unit 5. The pre-solder forming apparatus 1 is used to form pre-solder 30 on an aluminum electrode 10 formed of aluminum. Figure 2 The device is described above. The pre-solder 30 is solder that is pre-formed on the aluminum electrode 10 before being joined with the bonding object. When the aluminum electrode 10 is welded to the bonding object, for example, the pre-solder 30 can be melted and solidified to join the aluminum electrode 10 to the bonding object, or solder can be added to the pre-solder 30 to join the aluminum electrode 10 to the bonding object.

[0042] In the pre-solder forming apparatus 1, a laser L is irradiated onto an aluminum electrode 10 disposed on a frame 2 by a self-irradiation head 3. The aluminum electrode 10 is formed, for example, in a rectangular plate shape. Solder 20 is disposed on the aluminum electrode 10, and the solder 20 is melted and solidified by using the laser L, thereby bonding the solder 20 to the aluminum electrode 10 and forming pre-solder 30 on the aluminum electrode 10. Details of this bonding process are described below.

[0043] The frame 2 has a base portion 2a and a cover portion 2b disposed on the base portion 2a. The frame 2 is generally box-shaped, with the base portion 2a forming its bottom wall. An aluminum electrode 10, the object to be processed, is disposed on the base portion 2a. Solder 20 is disposed on the aluminum electrode 10. This solder 20 is a solder material bonded to the aluminum electrode 10. The solder 20 may, for example, be solder paste made by covering spherical metal materials with resin material.

[0044] The irradiation head 3 irradiates the aluminum electrode 10 with laser L. The irradiation head 3 is mounted on the cover 2b of the frame 2 in a manner that allows it to move along the XY plane. The XY plane is a plane perpendicular to the irradiation direction of the laser L irradiated by the irradiation head 3, i.e., the Z direction. Furthermore, the irradiation head 3 and the pedestal 2a only need to be able to move relative to each other along the XY plane; the pedestal 2a can also be configured as a stage capable of moving along the XY plane.

[0045] Camera 4 photographs the aluminum electrode 10 disposed on the pedestal 2a. Camera 4 is, for example, mounted on the cover 2b of the frame 2. Figure 1 This represents an example of an image P obtained through camera 4.

[0046] The control unit 5 is connected to each element of the pre-solder forming apparatus 1, which includes the irradiation head 3 and the camera 4, and controls each element of the pre-solder forming apparatus 1. The control unit 5 is, for example, a computer equipped with a processor such as a CPU and storage media such as RAM and ROM.

[0047] A method for forming pre-solder using the pre-solder forming apparatus 1 will be described. First, an aluminum electrode 10 is placed on the pedestal portion 2a, and solder 20 is placed on the aluminum electrode 10 (placement step). The placement step can be performed, for example, by a prescribed machine. In the placement step, solder 20 can be placed on the aluminum electrode 10 placed on the pedestal portion 2a, or the aluminum electrode 10 with solder 20 can be placed on the pedestal portion 2a. The solder 20 is, for example, distributed by a distributor (hereinafter referred to as...). Figure 11 The distributor 6 shown is disposed on the aluminum electrode 10.

[0048] Subsequently, by using laser L to melt and solidify the solder 20, the solder 20 is bonded to the aluminum electrode 10 (bonding process). Figure 2 More specifically, the solder 20 is melted by irradiation with laser L, and then the irradiation with laser L is stopped, thereby allowing the solder 20 to cool and solidify. In the bonding process, laser L is irradiated from the irradiation head 3. More specifically, the control unit 5 controls the irradiation head 3 to irradiate laser L.

[0049] In the bonding process, the laser L is irradiated in such a manner that the energy of the laser L irradiating the aluminum electrode 10 is greater than the energy of the laser L irradiating the solder 20. In this example, since the solder 20 is not irradiated by the laser L, the energy of the laser L irradiating the solder 20 is zero. In this example, as... Figure 2 As shown, at the start time of the joining process (at Figure 2 In the state shown on the left), the laser L is fully irradiated onto the aluminum electrode 10. In addition, the laser L is irradiated onto the surface 10a of the aluminum electrode 10 where the solder 20 is disposed.

[0050] Thus, in this example, laser L does not irradiate the solder 20; instead, it irradiates the aluminum electrode 10 entirely. Consequently, the aluminum electrode 10 is first heated. Then, the solder 20 is melted by the heat from the aluminum electrode 10. The molten solder 20... Figure 2 As shown on the right, the solder 20 moves to the heated portion (the portion irradiated by the laser L) of the aluminum electrode 10. The moving solder 20 solidifies in this portion and bonds to the aluminum electrode 10. Thus, a pre-solder 30 is formed on the aluminum electrode 10. In this bonding process, since the solder 20 easily wets the heated portion of the aluminum electrode 10, the solder 20 can be reliably bonded to the aluminum electrode 10.

[0051] Reference Figure 3 The operation of the pre-solder forming apparatus 1 in the bonding process will be explained. The following operations are performed by the control unit 5 controlling various elements of the pre-solder forming apparatus 1. First, the camera 4 acquires an image of the aluminum electrode 10 (step S11). Then, based on the image acquired by the camera 4 (e.g., through image processing), the control unit 5 determines whether the entire area to be irradiated by the laser L is located outside the solder 20 (step S12). If the determination result indicates that the entire area is located outside the solder 20 (yes in step S12), the control unit 5 causes the irradiation head 3 to begin irradiation by the laser L (step S13). On the other hand, if the determination indicates that at least a portion of the area is located inside the solder 20 (no in step S12), the control unit 5 moves the irradiation head 3 (step S14). Then, the control unit 5 executes the process of step S11 again. Through the above processing, irradiation by the laser L begins when the entire aluminum electrode 10 is irradiated by the laser L.

[0052] Here, refer to Figure 4 The location of the laser L's irradiation is explained. Figure 4 (a) and Figure 4 (b) shows a cross-sectional view on the top and a top view on the bottom. For example... Figure 4 As shown in (a), in the example above, the entire laser L irradiates the aluminum electrode 10. Figure 4 In (a), the center C of the laser L is located outside the solder 20 (solder 20 before melting) (solder 20 at the start time of the bonding process). The center C is the center of the irradiation area (irradiation spot) of the laser L on the surface 10a of the aluminum electrode 10. Furthermore, in Figure 4 In (a), when viewed from above (in the Z direction), the area of ​​laser L irradiating the aluminum electrode 10 is larger than the area of ​​laser L irradiating the solder 20. Furthermore, in this example, since laser L does not irradiate the solder 20, the area of ​​laser L irradiating the solder 20 is zero. The phrase "the center of the laser is located outside the solder" means that the center of the laser is located outside the solder's placement area. For example, as... Figure 4 As shown in the example, when the solder 20 is circular, it means that the center C of the laser L is located outside the outer periphery of the solder 20. When the solder 20 is annular, it means that the center C of the laser L is located outside the outer periphery or inside the inner periphery of the solder 20.

[0053] It is also possible to Figure 4 The laser L is shown in (b). Figure 4 In (b), a portion of the laser L irradiates the aluminum electrode 10, while the remainder of the laser L irradiates the solder 20. Figure 4 In (b), the center C of laser L is also located outside the solder 20. Additionally, in Figure 4 In (b), when viewed from above, the area of ​​the laser L irradiating the aluminum electrode 10 is also larger than the area of ​​the laser L irradiating the solder 20.

[0054] like Figure 4 As shown by the dashed line B in (b), the center C of the laser L can also be located on the outer edge of the solder 20. In this case, when viewed from above, the area of ​​the laser L irradiating the aluminum electrode 10 is also larger than the area of ​​the laser L irradiating the solder 20.

[0055] In any of the above cases, the energy of the laser L irradiating the aluminum electrode 10 is greater than the energy of the laser L irradiating the solder 20. For example, when the intensity distribution of the laser L is uniform, this energy is proportional to the irradiated area of ​​the laser L. When the intensity distribution of the laser L is non-uniform, this energy becomes the value obtained by integrating the intensity distribution of the laser L over the corresponding irradiated area. The intensity distribution of the laser L can also be a Gaussian distribution or a flat-top distribution (uniform distribution). Furthermore, the energy of the laser L irradiating the aluminum electrode 10 only needs to be greater than the energy of the laser L irradiating the solder 20, or it can be equal to... Figure 4 (a) and Figure 4 Unlike example (b), the center C of laser L is located inside solder 20.

[0056] Reference Figure 5 A comparative example is used to explain the advantages of the pre-solder formation method of the embodiment. Figure 5 In the comparative example of the pre-solder formation method, the laser L is completely irradiated onto the solder 20. In this case, the energy of the laser L irradiating the aluminum electrode 10 is zero, less than the energy of the laser L irradiating the solder 20. Therefore, the solder 20 is heated first, and the solder 20 melts before the aluminum electrode 10 is heated. As a result, the solder 20 does not easily wet the unheated aluminum electrode 10, and thus... Figure 5As shown on the right, the solder 20 forms a spherical shape and moves on the aluminum electrode 10, making it impossible to properly bond the solder 20 to the aluminum electrode 10. Furthermore, due to the small contact area between the solder 20 and the aluminum electrode 10, it is difficult to utilize the heat from the solder 20 to heat the aluminum electrode 10, thus also preventing proper bonding of the solder 20. Moreover, as... Figure 5 The reason why solder 20 is spherical as shown on the right is that solder 20 has a large free energy.

[0057] One reason for the poor wettability of the aluminum electrode 10 relative to the solder 20 is the influence of the passivation film formed on the surface of the aluminum electrode 10. When aluminum is exposed to the atmosphere, a passivation film composed of aluminum oxide (Al2O3) forms on its surface. Due to the presence of this passivation film, the solder does not easily wet the aluminum electrode.

[0058] To address this issue, flux is sometimes included in the solder to promote soldering. The flux in the solder is used to remove the passivation film formed on the surface of the aluminum electrode. However, in this case, removing the passivation film with flux takes time, thus raising concerns that the solder may melt before the passivation film is removed, causing the solder to become spherical and move on the aluminum electrode.

[0059] In this regard, as described above, in the pre-solder formation method of the embodiment, laser L is irradiated onto aluminum electrode 10, and aluminum electrode 10 is heated ( Figure 2 Then, the solder 20 is heated and melted by the heat from the aluminum electrode 10. The molten solder 20 moves to the heated portion of the aluminum electrode 10 and solidifies. Since the solder 20 easily wets the heated portion of the aluminum electrode 10, the solder 20 can be reliably bonded to the aluminum electrode 10. In addition, since the solder 20 moves (concentrates) to the heated portion of the aluminum electrode 10, the solder 20 can be easily positioned.

[0060] [Functions and Effects]

[0061] In the pre-solder formation method of the embodiment, the laser L is irradiated such that the energy of the laser L irradiating the aluminum electrode 10 is greater than the energy of the laser L irradiating the solder 20. Therefore, the aluminum electrode 10 can be heated before the solder 20, and the aluminum electrode 10 is in a heated state at the point when the solder 20 melts. As a result, the aluminum electrode 10 is easily wetted by the solder 20 at the bonding site with the solder 20, thereby enabling the solder 20 to be well bonded to the aluminum electrode 10. Therefore, according to the pre-solder formation method of the embodiment, pre-solder 30 can be well formed on the aluminum electrode 10. Furthermore, "the energy of the laser L irradiating the aluminum electrode 10 is greater than the energy of the laser L irradiating the solder 20" includes the case where the energy of the laser L irradiating the solder 20 is zero (i.e., the laser L does not irradiate the solder 20).

[0062] In the bonding process, the entire laser L is irradiated onto the aluminum electrode 10. This allows for stable heating of the aluminum electrode 10, thereby improving the yield. That is, for example, compared to the case where only a portion of the laser L is irradiated onto the aluminum electrode 10, the irradiation position of the laser L is easier to adjust, and the aluminum electrode 10 can be heated stably.

[0063] In the bonding process, a portion of the laser L can be directed onto the aluminum electrode 10, while the remainder of the laser L is directed onto the solder 20. In this case, both the aluminum electrode 10 and the solder 20 can be heated evenly, thus shortening the process.

[0064] In the bonding process, the laser L is irradiated with its center located outside the solder 20. This allows the laser L to be irradiated more easily than the laser L irradiating the solder 20. The pre-solder formation method of this embodiment is particularly effective when the intensity distribution of the laser L is a Gaussian distribution with high intensity in the central area, or a flat-top distribution with uniform intensity.

[0065] In the bonding process, the laser L is irradiated such that the area of ​​the laser L irradiating the aluminum electrode 10 is larger than the area of ​​the laser L irradiating the solder 20. Therefore, the laser L can be easily irradiated in such a way that the energy of the laser L irradiating the aluminum electrode 10 is greater than the energy of the laser L irradiating the solder 20.

[0066] In the bonding process, laser L is irradiated onto the surface 10a of the aluminum electrode 10 where the solder 20 is disposed. As a result, the solder 20 can be reliably bonded to the aluminum electrode 10.

[0067] The pre-solder forming apparatus 1 is used to form pre-solder 30 on an aluminum electrode 10 made of aluminum. The pre-solder forming apparatus 1 includes an irradiation head 3 (irradiation section) for irradiating with a laser L, and a control section 5 for controlling the irradiation head 3. The control section 5 irradiates the irradiation head 3 with the laser L in such a manner that the energy of the laser L irradiating the aluminum electrode 10 is greater than the energy of the laser L irradiating the solder 20 disposed on the aluminum electrode 10, causing the solder 20 to melt and solidify, thereby bonding the solder 20 to the aluminum electrode 10. Based on the pre-solder forming apparatus 1, for the above reasons, solder can be well bonded to the aluminum electrode 10.

[0068] [Variation Example]

[0069] like Figure 6As shown in the first modification, during the bonding process, the laser L can be irradiated while the pressing member 40, positioned opposite the solder 20 on the aluminum electrode 10, is in contact with the solder 20. The pressing member 40 is formed of a material that is permeable to the laser L. In this example, the pressing member 40 is formed of glass in a plate shape. In this example, the laser L is irradiated onto the surface 10a of the aluminum electrode 10 via the pressing member 40 (through the pressing member 40). In the first modification, the entire laser L is irradiated onto the aluminum electrode 10. By irradiating the solder 20 with the pressing member 40 pressed against it, the solder 20 is melted, and the movement of the solder 20 can be restricted by the pressing member 40.

[0070] Furthermore, the pre-solder formation method of the first modification can be suitably used when the solder 20 contains flux. For example... Figure 7 As shown, when the solder 20 contains flux 21, the solder 20 may be placed on the flux 21 and fail to bond the solder 20 well to the aluminum electrode 10.

[0071] In contrast, such as Figure 6 As shown, when using the pressure-adhesion member 40, since the heated solder 20 expands, the pressure-adhesion member 40 is used to restrict its movement upwards in the figure, thereby applying a force downwards (towards the aluminum electrode 10) to the solder 20 in the figure. Through this force, as... Figure 6 As shown, the solder 20 can push aside the flux 21 and come into contact with the aluminum electrode 10, thereby allowing the solder 20 to be well bonded to the aluminum electrode 10.

[0072] In the first modification, similarly to the embodiment described above, a pre-formed solder 30 can be well formed on the aluminum electrode 10. Furthermore, since the laser L is irradiated while the pressure member 40, positioned opposite the solder 20 on the aluminum electrode 10, is in contact with the solder 20, the solder 20 can be further well bonded to the aluminum electrode 10. Additionally, since the pressure member 40 is transmissive to the laser L, during the bonding process, the laser L is irradiated through the pressure member 40 onto the surface 10a of the aluminum electrode 10 where the solder 20 is disposed, thus irradiating the area overlapping with the pressure member 40. Furthermore, even solder 20 containing flux 21 can be well bonded to the aluminum electrode 10. Moreover, in the bonding process of the first modification, similarly to the embodiment described above, a portion of the laser L is irradiated onto the aluminum electrode 10, and the remainder of the laser L is irradiated onto the solder 20.

[0073] like Figure 8As shown in the second variation, during the bonding process, the solder 20 can be irradiated with the surrounding member 50 while viewed from above (from the direction of laser irradiation). The surrounding member 50 is formed of a material having a higher melting point than the solder 20 and lower bonding strength with the solder 20. Furthermore, the surrounding member 50 is formed of a material that is permeable to the laser L. In this example, the surrounding member 50 is formed of epoxy glass or silicone. The surrounding member 50 has an adhesion portion 51 disposed on the opposite side of the aluminum electrode 10 relative to the solder 20, and a sidewall portion 52 that surrounds the solder 20 when viewed from above. The adhesion portion 51 and the sidewall portion 52 are formed integrally, for example.

[0074] like Figure 8 As shown, in this example, laser L is irradiated on the outside of the surrounding member 50. In the second modification, the entire laser L is irradiated onto the aluminum electrode 10. By irradiating the solder 20 with the surrounding member 50 surrounding it, movement of the molten solder 20 can be suppressed, and the solder 20 can be reliably bonded to the aluminum electrode 10 inside the surrounding member 50. Furthermore, in the second modification, similar to the first modification, the solder 20 is melted by irradiating the laser L with the pressing portion 51 pressed against it, thus restricting movement of the solder 20 in the Z direction. That is, the pressing portion 51 can also be considered as a pressing member that performs the same function as the pressing member 40 in the first modification. In this case, the sidewall portion 52 can be considered as a surrounding member. In the bonding process of the second modification, laser L is irradiated with the pressing portion 51 in contact with the solder 20 and the solder 20 surrounded by the sidewall portion 52. Therefore, the solder 20 can be well bonded to the aluminum electrode 10. Furthermore, since the pressing portion 51 and the sidewall portion 52 are integrally formed, the number of components can be reduced, and the operation time can be shortened. Moreover, in the second modification, the surrounding member 50 may also lack the pressing portion 51 and only have the sidewall portion 52. In the bonding process of the second modification, similarly to the above embodiment, a portion of the laser L can be irradiated onto the aluminum electrode 10, and the remainder of the laser L can be irradiated onto the solder 20. Figure 8 In this example, the laser L is irradiated onto the aluminum electrode 10 from the outer side of the sidewall portion 52, but the laser L can also be irradiated onto the aluminum electrode 10 from the inner side of the sidewall portion 52. In this case, the laser L irradiates the aluminum electrode 10 through the pressing portion 51.

[0075] In the second variation, the pre-formed solder 30 can be formed well on the aluminum electrode 10 in the same manner as in the embodiment described above. Furthermore, since the laser L is irradiated while the solder 20 is surrounded by the surrounding member 50 in a top view, the movement of the molten solder 20 can be suppressed by the surrounding member 50, allowing the solder to be better bonded to the aluminum electrode 10. Additionally, since the surrounding member 50 is formed of epoxy glass or silicone, its thermal conductivity is reduced, preventing heat from escaping from the solder 20 through the surrounding member 50. Furthermore, the heat resistance of the surrounding member 50 is improved, preventing damage (e.g., scorching) caused by the temperature during processing. Moreover, since the surrounding member 50 is translucent relative to the laser L, it is not necessary to avoid irradiating the laser L through the surrounding member 50, simplifying the irradiation process.

[0076] like Figure 9 As shown in the third modification, during the bonding process, while the surface 10a of the aluminum electrode 10 is in contact with the solder paste layer 60, which serves as the base material for the solder 20, a laser L can be irradiated onto the surface 10b opposite to the surface 10a of the aluminum electrode 10. In the third modification, the surface 10b is heated by the irradiation of the laser L, and this heat is transferred to the surface 10a, thereby melting a portion of the solder paste layer 60 (solder 20). The molten solder paste layer 60 solidifies and bonds to the surface 10a of the aluminum electrode 10. In the third modification, since the molten portion (solder 20) in the solder paste layer 60 is surrounded by the unmolten portion in the solder paste layer 60, movement of the molten solder 20 can be suppressed, and the solder 20 can be reliably bonded to the aluminum electrode 10. That is, the unmolten portion in the solder paste layer 60 can also be considered as a surrounding member that performs the same function as the surrounding member 50 in the second modification.

[0077] In the third variation, the prepared solder 30 can be well formed on the aluminum electrode 10 in the same manner as in the above embodiment. In addition, since the laser L is irradiated on the surface 10b opposite to the surface 10a on which the solder 20 is disposed in the aluminum electrode 10, it is not necessary to avoid irradiating the solder 20 with the laser L, thus simplifying the irradiation of the laser L.

[0078] like Figure 10 As shown in the fourth variation, during the bonding process, the surface 10b opposite to the surface 10a of the aluminum electrode 10 may also be irradiated with laser L. In the fourth variation, the surface 10b is heated by the irradiation of laser L, and this heat is transferred to the surface 10a, thereby melting the solder 20. The molten solder 20 solidifies and bonds to the surface 10a of the aluminum electrode 10.

[0079] In the fourth variation, the prepared solder 30 can also be well formed on the aluminum electrode 10 in the same manner as in the above embodiment. In addition, since the laser L is irradiated on the surface 10b opposite to the surface 10a on which the solder 20 is disposed in the aluminum electrode 10, it is not necessary to avoid irradiating the solder 20 with the laser L, thus simplifying the irradiation of the laser L.

[0080] like Figure 11 As shown in the fifth variation, the solder preparation apparatus 1 may also omit the camera 4. In this case, the control unit 5 controls the irradiation position of the laser L of the irradiation head 3 via numerical control instead of image recognition. In this case, as... Figure 12 As shown, firstly, the distributor 6 applies (coats) solder 20 in a predetermined amount to a predetermined position on the aluminum electrode 10 (step S21). Then, the control unit 5 obtains the position information of the solder 20 from the distributor 6 (step S22). Next, the control unit 5 moves the irradiation head 3 to the position corresponding to the solder 20 (step S23). Then, the control unit 5 causes the irradiation head 3 to begin irradiating the laser L (step S24). Through the above processing, for example, irradiation of the laser L begins while the entire laser L is irradiated onto the aluminum electrode 10. In the fifth modification, the solder 20 can also be well bonded to the aluminum electrode 10 in the same manner as in the above embodiment. In the bonding process of the fifth modification, a portion of the laser L can be irradiated onto the aluminum electrode 10, and the remaining portion of the laser L can be irradiated onto the solder 20, just as in the above embodiment.

[0081] This invention is not limited to the embodiments and modifications described above. For example, the materials and shapes of the structures are not limited to those described above, and various materials and shapes can be used. The shape of the irradiation area of ​​the laser L is not limited to... Figure 5 The circular shape shown can also be any shape. The shape of the irradiation area of ​​the laser L can also be annular (ring-shaped). The shape of the aluminum electrode 10 is not limited to a plate shape and can be any shape.

[0082] In the above embodiment, the laser is irradiated in such a way that the energy of the laser L irradiating the aluminum electrode 10 is greater than the energy of the laser L irradiating the solder 20. However, the laser L may also be irradiated in such a way that the energy of the laser L absorbed by the aluminum electrode 10 is greater than the energy of the laser L absorbed by the solder 20. That is, the laser L may also be irradiated considering the absorptivity of the laser L on the aluminum electrode 10 and the solder 20. The absorptivity of the solder 20 is higher than that of the aluminum electrode 10. The energy of the laser L absorbed by the aluminum electrode 10 is the amount obtained by multiplying the energy of the laser L irradiating the aluminum electrode 10 by the absorptivity of the laser L on the aluminum electrode 10, and the energy of the laser L absorbed by the solder 20 is the amount obtained by multiplying the energy of the laser L irradiating the solder 20 by the absorptivity of the laser L on the solder 20. In this case, the solder 20 can also be well bonded to the aluminum electrode 10.

[0083] Explanation of symbols

[0084] 1…Prepared solder forming apparatus, 3…Irradiation head (irradiation section), 5…Control section, 10…Aluminum electrode, 10a, 10b…Surface, 20…Solder, 21…Fluoride, 30…Prepared solder, 40…Pressure attachment member, 50…Enclosing member, 51…Pressure attachment section (Pressure attachment member), 52…Side wall section (Enclosing member), C…Center, L…Laser.

Claims

1. A method for forming a pre-solder, wherein, This is a method for forming pre-solder on an aluminum electrode made of aluminum. have: The configuration process involves configuring solder on the aluminum electrode; and The bonding process involves using a laser to melt and solidify the solder, thereby bonding the solder to the aluminum electrode. In the bonding process, the laser is irradiated in such a manner that the energy of the laser irradiating the aluminum electrode is greater than the energy of the laser irradiating the solder.

2. The method for forming pre-solder as described in claim 1, wherein, In the bonding process, the entire laser beam is directed onto the aluminum electrode.

3. The method for forming pre-solder as described in claim 1, wherein, In the bonding process, a portion of the laser is directed onto the aluminum electrode, and the remainder of the laser is directed onto the solder.

4. The method for forming pre-solder as described in claim 1 or 3, wherein, In the bonding process, the laser is irradiated with its center located outside the solder.

5. The method for forming pre-solder as described in claim 1 or 3, wherein, In the bonding process, the laser is irradiated such that the area of ​​the laser irradiating the aluminum electrode is larger than the area of ​​the laser irradiating the solder.

6. The method for forming pre-solder as described in claim 1 or 2, wherein, In the bonding process, the laser is irradiated while the pressure attachment member, which is positioned on the opposite side of the aluminum electrode relative to the solder, is in contact with the solder.

7. The method for forming pre-solder as described in claim 6, wherein, The pressure-adhesion member is transmissive to the laser. In the bonding process, the laser is irradiated onto the surface of the aluminum electrode on which the solder is disposed via the pressing member.

8. The method for forming pre-solder as described in claim 1 or 2, wherein, In the joining process, the solder is irradiated with the laser while it is surrounded by the surrounding member when viewed from the irradiation direction of the laser.

9. The method for forming pre-solder as described in claim 8, wherein, The surrounding member is formed of epoxy glass or silicone.

10. The method for forming pre-solder as described in claim 8, wherein, The surrounding member is transparent to the laser.

11. The method for forming pre-solder as described in claim 1 or 2, wherein, In the bonding process, the lamination member, positioned opposite the aluminum electrode to the solder, contacts the solder, and the solder is surrounded by the surrounding member when viewed from the irradiation direction of the laser, before being irradiated by the laser. The pressing member is integrally formed with the surrounding member.

12. The method for forming pre-solder as described in claim 1 or 2, wherein, In the bonding process, the laser is used to irradiate the surface of the aluminum electrode on which the solder is disposed.

13. The method for forming pre-solder as described in claim 1 or 2, wherein, In the bonding process, the laser is irradiated onto the surface of the aluminum electrode opposite to the surface on which the solder is disposed.

14. The method for forming pre-solder as described in claim 1 or 2, wherein, In the configuration process, the solder containing flux is configured onto the aluminum electrode.

15. A pre-solder forming apparatus, wherein, It is a pre-solder forming apparatus for forming pre-solder on aluminum electrodes made of aluminum. have: The irradiation section, which irradiates with laser light; and The control unit controls the irradiation unit. The control unit irradiates the irradiation unit with the laser in such a way that the energy of the laser irradiating the aluminum electrode is greater than the energy of the laser irradiating the solder disposed on the aluminum electrode, thereby melting and solidifying the solder and bonding the solder to the aluminum electrode.

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