Joined body and method for manufacturing joined body

Abstract

Provided are: a joined body having high joining strength and favorable conductivity; and a method for manufacturing a joined body. This joined body comprises: an insulating substrate having electrical insulating properties; an anisotropic conductive member which is provided so as to pass through in the thickness direction of the insulating substrate, and has a plurality of conductive paths including a protrusion portion protruding from at least one surface of the insulating substrate; and a member to be joined which is joined to the anisotropic conductive member. The member to be joined has a resin layer and a metal layer, and the resin layer is formed of polyimide or polybenzoxazole.

Description

Joint and method for manufacturing the joint

[0001] The present invention relates to a joint in which an anisotropic conductive member and a member to be joined are joined, and to a method for manufacturing the joint, and more particularly to a joint in which the member to be joined has a resin layer and a metal layer, and to a method for manufacturing the joint.

[0002] Currently, various joining methods are used to obtain electrical connections between electronic components such as semiconductor elements, and between electronic components and circuit boards. Various forms have been proposed for connecting semiconductor elements to each other, and between semiconductor elements and substrates, such as wafer-on-wafer, chip-on-wafer, or chip-on-chip. Anisotropic conductive members that have conductivity in the thickness direction of an insulating substrate are used as electronic connecting members for joining the aforementioned electronic components. For example, a specific example is shown in Patent Document 1.

[0003] For example, Patent Document 1 describes a method for manufacturing a multilayer wiring board comprising an anisotropic conductive bonding member and a wiring board having a plurality of electrodes, wherein the anisotropic conductive bonding member has an insulating substrate made of an inorganic material and a plurality of conductive passages made of a conductive material that penetrate the insulating substrate in the thickness direction and are insulated from each other, the plurality of conductive passages have protruding portions that protrude from the surface of the insulating substrate, the height of the plurality of electrodes on the wiring board is 10 μm or less, and the method for manufacturing a multilayer wiring board comprises, in this order, a temporary bonding process in which the anisotropic conductive bonding member and the wiring board are bonded using a non-conductive thermosetting resin, and a final bonding process in which the conductive passages on the anisotropic conductive bonding member and the electrodes on the wiring board are electrically bonded by heating at a temperature below the curing temperature of the thermosetting resin.

[0004] Japanese Patent Publication No. 2018-037509

[0005] When the above-mentioned anisotropic conductive member is used as an electronic connection member, it is preferable that the bonding strength is high and the conductivity is good. However, in Patent Document 1, as described above, a temporary bonding process is performed in which the anisotropic conductive bonding member and the wiring board are bonded using a non-conductive thermosetting resin, followed by the main bonding process. After the main bonding process, the thermosetting resin is cured by heating it to a temperature above its curing temperature, but the thermosetting resin may not provide sufficient bonding strength compared to the physical bonding between the electrode and the conductive passage. In addition, if the thermosetting resin penetrates the bonding surface, conductivity may be impaired. The object of the present invention is to provide a bonded body and a method for manufacturing a bonded body that have high bonding strength and good conductivity.

[0006] The above-mentioned objective can be achieved with the following configuration. Invention [1] is a joint comprising an insulating substrate having electrical insulating properties, an anisotropic conductive member having a plurality of conductive passages provided through the thickness direction of the insulating substrate and having protrusions protruding from at least one surface of the insulating substrate, and a member to be joined to the anisotropic conductive member, wherein the member to be joined has a resin layer and a metal layer, and the resin layer is polyimide or polybenzoxazole.

[0007] Invention [2] is the bonded body according to Invention [1], wherein the member to be bonded has a convex portion, and the anisotropic conductive member has a concave portion corresponding to the convex portion. Invention [3] is the bonded body according to Invention [1] or [2], wherein the member to be bonded has an area ratio of the resin layer to the metal layer, expressed as the area of ​​the resin layer / the area of ​​the metal layer, of 5 to 10%. Invention [4] is the bonded body according to any one of Inventions [1] to [3], wherein a plurality of anisotropic conductive members are arranged via the member to be bonded in the lamination direction between the anisotropic conductive member and the member to be bonded. Invention [5] is the bonded body according to any one of Inventions [1] to [4], wherein the metal layer of the member to be bonded contains Cu, Au, Ag, or Al. Invention [6] is the bonded body according to any one of Inventions [1] to [5], wherein the member to be bonded is a power semiconductor element.

[0008] Invention [7] is a method for manufacturing a joined body, comprising a joining step of joining a member to be joined and a joining member, wherein the joining step pressurizes the member to be joined and the joining member when they are heated and when they are cooled. Invention [8] is a method for manufacturing a joined body according to Invention [7], wherein the oxygen concentration at the time of joining the member to be joined and the joining member is 40 ppm or less. Invention [9] is a method for manufacturing a joined body according to Invention [7] or [8], wherein the joining member is an anisotropic conductive member having an insulating substrate having electrical insulating properties and a plurality of conductive passages provided that penetrate the thickness direction of the insulating substrate and have protrusions that protrude from at least one surface of the insulating substrate, and the member to be joined has a resin layer and a metal layer, and the resin layer is polyimide or polybenzoxazole.

[0009] According to the present invention, it is possible to provide a joint with high bonding strength and good conductivity, and a method for manufacturing the joint.

[0010] This is a schematic plan view showing a first example of a joint according to an embodiment of the present invention. This is a schematic cross-sectional view showing a first example of a joint according to an embodiment of the present invention. This is a schematic cross-sectional view showing a second example of a joint according to an embodiment of the present invention. This is a schematic diagram showing an example of an apparatus used in the method for manufacturing a joint according to an embodiment of the present invention. This is a schematic diagram showing an example of joining conditions for the method for manufacturing a joint according to an embodiment of the present invention. This is a schematic cross-sectional view showing a third example of a joint according to an embodiment of the present invention. This is a schematic cross-sectional view showing a fourth example of a joint according to an embodiment of the present invention. This is a schematic cross-sectional view showing an example of an anisotropic conductive member of a laminate according to an embodiment of the present invention. This is a schematic plan view showing an example of an anisotropic conductive member of a laminate according to an embodiment of the present invention.

[0011] The joint and method for manufacturing the joint of the present invention will be described in detail below based on the preferred embodiments shown in the attached drawings. The figures described below are illustrative for illustrating the present invention and have been simplified for illustrative purposes. Therefore, the present invention is not limited to the figures shown below. In the following, the "~" indicating a numerical range includes the numerical values ​​indicated on both sides. For example, ε is the numerical value ε α ~ numerical value ε β Therefore, the range of ε is the numerical value ε α and the numerical value ε βThis range includes ε α ≦ε≦ε β The following applies to "specific angles" and "parallelism": unless otherwise specified, the tolerance range is generally acceptable in the relevant technical field. Similarly, the tolerance range for length and thickness is generally acceptable in the relevant technical field unless otherwise specified. The tolerance range for temperature, pressure, and concentration is also generally acceptable in the relevant technical field unless otherwise specified.

[0012] In the present invention, a jointed body is defined simply by indicating a state in which an anisotropic conductive member and a member to be joined are joined together. The jointed body in the present invention does not use a manufacturing method to define its structure. The jointed body constitutes part of a functional device or performs a specific function on its own. Specific examples of jointed bodies are described below. [First Example of a Joined Body] Figure 1 is a schematic plan view showing a first example of a jointed body according to an embodiment of the present invention. Figure 2 is a schematic cross-sectional view showing a first example of a jointed body according to an embodiment of the present invention. Note that in Figure 1, the guide passage 52 (see Figure 2) and the protruding portion 52a (see Figure 8) are omitted from the illustration. Also, in Figure 2, the protruding portions 52a and 52b (see Figure 8) are omitted from the illustration. The jointed body 10 shown in Figure 1 includes, for example, an anisotropic conductive member 12, a first member to be joined 14, and a second member to be joined 16. The jointed body 10 has a configuration having two members to be joined. The joined body 10 is constructed by stacking the first member to be joined 14, the anisotropic conductive member 12, and the second member to be joined in that order from bottom to top. The direction in which the first member to be joined 14, the anisotropic conductive member 12, and the second member to be joined are stacked is the stacking direction Ds (see Figure 2). It is preferable that the thickness direction Dt of the insulating base material 50 of the anisotropic conductive member 12 and the stacking direction Ds are substantially parallel.

[0013] The anisotropic conductive member 12 will be described in detail later, but it has an insulating substrate 50 having electrical insulating properties and a plurality of conductive passages 52 that penetrate the insulating substrate 50 in the thickness direction Dt and have protrusions 52a, 52b (see Figure 8) that protrude from at least one surface of the insulating substrate 50. The protrusions are physically and electrically joined to the metal layer, which will be described later. For this reason, the anisotropic conductive member 12 needs to have protrusions on the surface facing the metal layer. The surface 12a of the anisotropic conductive member 12 is the surface 50a (see Figure 8) of the insulating substrate 50. The back surface 12b of the anisotropic conductive member 12 is the back surface 50b (see Figure 8) of the insulating substrate 50. The surface 12a and the back surface 12b of the anisotropic conductive member 12 are opposing surfaces in the thickness direction Dt of the insulating substrate 50.

[0014] The first member to be joined 14 has a substrate 20 and a resin layer 22, a metal layer 24, and a metal layer 25 provided on the surface 20a of the substrate 20. As shown in Figure 1, the substrate 20 has, for example, a rectangular shape in plan view. This rectangle has, for example, all interior angles of 90°. Here, viewing the joined body 10 from the surface 12a side of the anisotropic conductive member 12 is called a plan view. The resin layer 22 is provided along the outer edges of three of the four sides of the surface 20a of the substrate 20. On the surface 20a of the substrate 20, a rectangular section 21b is provided on the remaining side 20d, sharing a part of the side, and the resin layer 22 is provided along the outer circumference of the section 21b. The resin layer 22 is positioned to protrude towards the center of the substrate 20 along the surface 20a of the substrate 20 in one direction D of the substrate 20. This protruding portion is the convex portion 23 described later. The region on the surface 20a of the substrate 20 surrounded by the resin layer 22 is section 21a. In this way, the resin layer 22 is arranged in a pattern, for example, to divide the substrate 20 into two sections 21a and 21b. In one direction D of the substrate 20, there is a resin layer 22 between section 21a and section 21b, and this is a protrusion 23. The height of the protrusion 23 made of the resin layer 22 is higher than the metal layers 24 and 25, and the protrusion 23 protrudes from the surface 20a of the substrate 20 toward the anisotropic conductive member 12. Note that one direction D of the substrate 20 is the direction parallel to the side 20e which is perpendicular to the side 20d.

[0015] The rectangular section 21b has, for example, all interior angles of 90°. Sections 21a and 21b have different areas, with section 21a having a larger area than section 21b. A metal layer 24 is provided in section 21a, and a metal layer 25 is provided in section 21b. The metal layers 24 and 25 function, for example, as source electrodes, drain electrodes, or gate electrodes when the first bonded member 14 is a transistor. As a method for forming sections 21a and 21b of the first bonded member 14, for example, a resin film is formed on the entire surface 20a of the substrate 20, and patterns corresponding to sections 21a and 21b are formed on the resin film by laser processing. For example, an ultrashort pulse laser with a wavelength of 530 nm is used for laser processing.

[0016] The anisotropic conductive member 12 has, for example, a rectangular shape in plan view. The anisotropic conductive member 12 has a recess 13 that corresponds to the protrusion 23 of the first member to be joined 14. The anisotropic conductive member 12 and the metal layer 24 and metal layer 25 are physically and electrically joined with the protrusion 23 of the first member to be joined 14 fitted into the recess 13 of the anisotropic conductive member 12. Having a recess 13 that corresponds to the protrusion 23 of the first member to be joined 14 is preferable because it further increases the bonding strength, especially the shear strength of the substrate 20 in one direction D. Note that the protrusion 23 of the first member to be joined 14 may not protrude; in this case, the anisotropic conductive member 12 will not have a recess 13 that corresponds to the protrusion 23 of the first member to be joined 14. The configuration in which the protrusion 23 does not protrude from the first member to be joined 14 means that the height of the protrusion 23 is less than or equal to the height of the metal layers 24 and 25. As described above, a configuration in which the protrusion 23 does not protrude is also called a configuration without the protrusion 23. A configuration in which the protrusion 23 protrudes is also called a configuration with the protrusion 23.

[0017] The second member to be joined 16 has a substrate 26, a wiring layer 27, and a resin layer (not shown). The wiring layer 27 corresponds to the metal layers 24 and 25 of the first member to be joined 14. The second member to be joined 16 has, for example, a rectangular shape in plan view, and for example, all interior angles are 90°. The external shape of the second member to be joined 16 is similar to that of the first member to be joined 14. The area of ​​the second member to be joined 16 is smaller than that of the first member to be joined 14. The area is in the order of anisotropic conductive member 12, second member to be joined 16, and first member to be joined 14. As shown in Figure 1, the wiring layer 27 is provided in the region where the surface 12a of the anisotropic conductive member 12 and the back surface 26b of the substrate 26 of the second member to be joined 16 overlap. The anisotropic conductive member 12 and the wiring layer 27 are physically and electrically joined.

[0018] In the joint 10, the metal layers 24 and 25 and the wiring layer 27 are electrically connected by the anisotropic conductive member 12. Here, being physically and electrically joined means that even when the joint 10 is transported for handling, the anisotropic conductive member 12 and the first joined member 14 and the second joined member 16 do not separate, and there is conductivity between the first joined member 14, the anisotropic conductive member 12, and the second joined member 16, allowing electrical signals to be input to the first joined member 14 and the second joined member 16, and allowing electrical signals to be output from the first joined member 14 and the second joined member 16 to the outside. The joint 10 has high bonding strength and good conductivity due to the above configuration. The joint 10 has a configuration having one anisotropic conductive member 12 and two joined members, but the joint only needs to have a configuration in which at least one anisotropic conductive member and one joined member are joined.

[0019] The substrate 20 is made of, for example, SiC. The substrate 26 is also made of, for example, SiC. The resin layer 22 is made of, for example, polyimide or polybenzoxazole (PBO). Polyimide and polybenzoxazole (PBO) are preferred because they have excellent electrical insulation properties. The metal layer 24 and the metal layer 25 are made of, for example, Cu, Au, Ag, or Al. Cu, Au, Ag, or Al may be individual metals or alloys thereof. An example of an alloy is an Al-Si alloy. Cu, Au, Ag, and Al, as well as their alloys, are preferred because they bond well with the anisotropic conductive member. The wiring layer 27 is made of the same individual metal or alloy as the metal layer 24 and the metal layer 25. The metal layer 24, the metal layer 25, and the wiring layer 27 are formed, for example, by electroplating. The resin layer (not shown) of the second member to be joined 16 is made of, for example, polyimide or polybenzoxazole (PBO).

[0020] [Second Example of a Joined Body] Figure 3 is a schematic cross-sectional view showing a second example of a laminate according to an embodiment of the present invention. In Figure 3, the same components as those in the joined body 10 shown in Figures 1 and 2 are denoted by the same reference numerals, and their detailed descriptions are omitted. The joined body 11 shown in Figure 3 differs from the joined body 10 shown in Figures 1 and 2 in that the first member to be joined 14a does not have a resin layer 22 except for the protrusions 23 shown in Figures 1 and 2, and the other components are the same as those in the joined body 10 shown in Figure 1. As shown in the joined body 11 in Figure 3, the first member to be joined 14a can be configured without a resin layer 22 except for the protrusions 23 shown in Figures 1 and 2. The first member to be joined 14a may also have a configuration in which the protrusions 23 do not protrude, similar to the first member to be joined 14 described above, in which case the anisotropic conductive member 12 will not have a recess 13 corresponding to the protrusions 23 of the first member to be joined 14a.

[0021] [First Example of Method for Manufacturing a Joined Body] Figure 4 is a schematic diagram showing an example of an apparatus used in the method for manufacturing a joined body according to an embodiment of the present invention. Figure 5 is a schematic diagram showing an example of joining conditions for the method for manufacturing a joined body according to an embodiment of the present invention. In Figure 4, the same reference numerals are used for components identical to the joined body 10 shown in Figures 1 and 2 and the joined body 11 shown in Figure 3, and their detailed descriptions are omitted. In Figure 5, the numeral L indicates the pressure profile in the joining process. The numeral T indicates the temperature profile in the joining process. The numeral C indicates the oxygen concentration profile in the joining process. The joining process includes a joining step of joining a member to be joined and a joining member. The joining member is, for example, the anisotropic conductive member 12 shown in Figure 3 above. The members to be joined are, for example, the first member to be joined 14a and the second member to be joined 16 shown in Figure 3 above.

[0022] For the manufacture of the bonded body 10, methods such as flip-chip bonding (FCB) and wafer bonding (WB) can be used as bonding methods. For the manufacture of the bonded body 11, for example, the apparatus 30 shown in Figure 4 is used, but is not limited to this. The apparatus 30 shown in Figure 4 has a stage 32 and a chamber 34 that is movable on the surface 32a of the stage 32. The stage 32 is equipped with a heater 33 inside and can also heat the first member to be bonded 14a, the anisotropic conductive member 12 and the second member to be bonded 16. A pressure head 35 is provided inside 34a of the chamber 34, facing the surface 32a of the stage 32. The pressure head 35 can move closer to and further away from the surface 32a of the stage 32. The pressure head 35 can press the second member to be bonded 16 against the anisotropic conductive member 12 and the first member to be bonded 14a. Furthermore, the pressurizing head 35 is equipped with a heater (not shown) that can heat the second member to be joined 16, the anisotropic conductive member 12, and the first member to be joined 14a. A gas supply unit 36 ​​is also provided to supply gas to the interior 34a of the chamber 34. A concentration meter 38 is provided to measure the oxygen concentration inside the interior 34a of the chamber 34. The gas supply unit 36 ​​can supply a predetermined amount of a specific type of gas, such as nitrogen gas, to the interior 34a of the chamber 34. The oxygen concentration inside the interior 34a of the chamber 34 is controlled by adjusting the amount of nitrogen gas supplied from the gas supply unit 36.

[0023] The chamber 34 constitutes a closed space, and the joining process is carried out inside 34a. The configuration of the chamber 34 is not particularly limited as long as it can house the objects to be joined and carry out the joining process. A pump (not shown) may be provided in the chamber 34 to reduce the pressure inside 34a of the chamber 34. In this case, it is preferable to provide a pressure gauge (not shown) in the chamber 34 to measure the pressure inside 34a.

[0024] A bonding step is performed inside 34a of a chamber 34 of an apparatus 30. Specifically, a first member to be bonded 14a is placed on a surface 32a of a stage 32, an anisotropic conductive member 12 is placed on the first member to be bonded 14a, and a second member to be bonded 16 is placed on the anisotropic conductive member 12. In this state, the pressure head 35 presses the second member to be bonded 16 toward the anisotropic conductive member 12, and pressurizes the pressure head 35 until the pressure reaches a preset pressure shown in FIG. 5. At this time, for example, nitrogen gas is supplied from the gas supply unit 36 into the interior 34a of the chamber 34 to lower the oxygen concentration in the interior 34a of the chamber 34. The interior 34a of the chamber 34 is replaced with nitrogen gas. In a state where the oxygen concentration in the interior 34a of the chamber 34 becomes equal to or lower than a preset concentration as shown in FIG. 5, the heater (not shown) of the stage 32 and the heater (not shown) of the pressure head 35 are heated, and the first member to be bonded 14a, the anisotropic conductive member 12 and the second member to be bonded 16 are heated to a preset bonding temperature (see FIG. 5). Bonding starts when the bonding temperature is reached. The bonding temperature is maintained for a preset period of time. Thereby, bonding is performed. A period in which the oxygen concentration in the interior 34a of the chamber 34 is adjusted to be equal to or lower than a preset concentration as shown in FIG. 5 and heating is performed up to the bonding temperature is referred to as a replacement region R of the bonding step １ . After the bonding temperature is reached, that is, after the replacement region R １ , a period in which the bonding temperature is maintained for a preset time is referred to as a bonding region R of the bonding step ２ .

[0025] After a predetermined time has elapsed for the bonding temperature, the supply of nitrogen gas from the gas supply unit 36 ​​to the interior 34a of the chamber 34 is stopped. As a result, the oxygen concentration inside the chamber 34a increases as shown in Figure 5. After maintaining the bonding temperature for a predetermined time, the heating of the heater of the stage 32 and the heater of the pressurizing head 35 is stopped. Then, as shown in Figure 5, the pressure is maintained, i.e., the pressurized state is maintained while cooling to room temperature, and the pressurization of the pressurizing head 35 is released. In the bonding process, the first member to be bonded 14a, the anisotropic conductive member 12 (bonding member), and the second member to be bonded 16 are pressurized during heating and cooling. In this way, a bonded body 11 (see Figure 3) of the first member to be bonded 14a, the anisotropic conductive member 12 (bonding member), and the second member to be bonded 16 is obtained. Then, the bonded body is removed from the chamber 34. Furthermore, after maintaining the bonding temperature for a predetermined time, i.e., in the bonding region R ２ After that, the period during which the pressurized state is maintained and the mixture is cooled to room temperature is called the cooling region R of the bonding process. ３ This means that by applying pressure to the first member to be joined 14a, the anisotropic conductive member 12 (joining member), and the second member to be joined 16 during heating and cooling, the pressurized state is maintained until the joining process is completed. As a result, close contact between the anisotropic conductive member and the member to be joined is maintained during the joining process, resulting in a good bond and high joint strength. Moreover, since the constituent metals are directly joined and have good conductivity, the conductivity between the first member to be joined 14a and the second member to be joined 16 in the joined body 11 is also good.

[0026] It is preferable to temporarily join the first member to be joined 14a, the anisotropic conductive member 12, and the second member to be joined 16 before the joining process. This is preferable because it physically fixes the first member to be joined 14a, the anisotropic conductive member 12, and the second member to be joined 16, thereby preventing them from separating. This allows the first member to be joined 14a, the anisotropic conductive member 12, and the second member to be joined 16 to be transported while they are positioned on top of each other.

[0027] The atmosphere during the joining process, for example, the oxygen concentration inside the chamber 34a at the time of joining the members to be joined and the joining members, is preferably 40 ppm or less, more preferably 30 ppm or less, and even more preferably 10 ppm or less, in order to suppress oxidation of the passages of the anisotropic conductive member 12, etc. The lower limit of the oxygen concentration is ideally 0 ppm.

[0028] In the joining process, it is preferable that the joining temperature between the members to be joined and the joining member is 150°C to 350°C. A joining temperature of 150°C to 350°C is preferable because it allows for more reliable joining. The joining temperature is the temperature of the heater of the stage 32 and the temperature of the heater of the pressure head 35. The temperatures of the heater of the stage 32 and the heater of the pressure head 35 are, for example, the set temperatures of each heater. To achieve the set joining temperature, for example, the set temperature of the heater of the stage 32 and the set temperature of the heater of the pressure head 35 are set to be the same. In the joining process, it is preferable that the joining pressure is 5 MPa to 150 MPa. A joining pressure of 5 MPa to 150 MPa is preferable because it allows for more reliable joining. The joining pressure is the value obtained by dividing the pressurizing load on the anisotropic conductive member 12 by the area of ​​the anisotropic conductive member 12.

[0029] Furthermore, in the above-described apparatus 30, if the configuration of the joint consists only of the first member to be joined 14a and the anisotropic conductive member 12, the anisotropic conductive member 12 is placed on the first member to be joined 14a placed on the stage 32, and the anisotropic conductive member 12 is pressed with the pressure head 35 to join the first member to be joined 14a and the anisotropic conductive member 12 in the same manner as the joining method described above. Even when the configuration of the joint consists only of the first member to be joined 14a and the anisotropic conductive member 12, the pressurized state is maintained until the joining process is completed, so that close contact between the anisotropic conductive member and the member to be joined is maintained during the joining process, resulting in a good joint and high joint strength. Moreover, the conductivity between the first member to be joined 14a and the anisotropic conductive member 12 in the joint 11 (see Figure 3) is also good.

[0030] As described above, the method for manufacturing the joined body was explained using the anisotropic conductive member 12, the first member to be joined 14a, and the second member to be joined 16 shown in Figure 3, but it is not limited to this. The joined body 10 (see Figures 1 and 2) can be manufactured using the first member to be joined 14 shown in Figures 1 and 2 instead of the first member to be joined 14a. Even when manufacturing the joined body 10 shown in Figures 1 and 2 using the first member to be joined 14 shown in Figures 1 and 2, the joined body can be manufactured in the manner described above. When manufacturing the joined body, the first member to be joined 14, the anisotropic conductive member 12 (joining member), and the second member to be joined 16 are pressurized during heating and cooling, and the pressurized state is maintained until the joining process is completed. As a result, close contact between the anisotropic conductive member and the member to be joined is maintained during the joining process, a good bond can be achieved, and the joint strength is increased. Furthermore, since the constituent metals are directly joined together and have good conductivity, the conductivity between the first joined member 14 and the second joined member 16 in the joined body 10 is also good.

[0031] [Third Example of a Joined Body] Figure 6 is a schematic cross-sectional view showing a third example of a laminate according to an embodiment of the present invention. In Figure 6, the same components as those in the joined body 10 shown in Figures 1 and 2 are denoted by the same reference numerals, and their detailed descriptions are omitted. The joined body 11a shown in Figure 6 differs from the joined body 10 shown in Figures 1 and 2 in that an anisotropic conductive member 40 is joined via a metal layer 29 provided on the back surface 14b of the first member to be joined 14, and an insulating heat dissipation circuit board 42 is joined to the back surface 40b of the anisotropic conductive member 40. The other configurations are the same as those of the joined body 10 shown in Figure 1. In the joined body 11a as well, it is preferable that the thickness direction Dt of the insulating base material 50 of the anisotropic conductive member 12 and the lamination direction Ds are substantially parallel.

[0032] The metal layer 29 may be formed over the entire surface of the back surface 14b of the first member to be joined 14, or it may be formed in a pattern on the back surface 14b of the first member to be joined 14. If the metal layer 29 is formed in a pattern, a resin layer may also be formed. The metal layer 29 is composed of a single metal or an alloy, similar to the metal layers 24 and 25. The resin layer is composed of, for example, polyimide or polybenzoxazole (PBO). The anisotropic conductive member 40 has the same configuration as the anisotropic conductive member 12 (see Figure 2) described above, except that it is a flat plate without the recess 13 (see Figure 2). The insulating heat dissipation circuit board 42 is, for example, provided with a metal layer 44 on the surface 43a of a ceramic substrate 43, and a metal layer 45 on the back surface 43b of the ceramic substrate 43. The back surface 40b of the anisotropic conductive member 40 and the surface 44a of the metal layer 44 are joined together. In the bonded body 11a, a heat sink can be bonded to the surface 45a of the metal layer 45, for example. The ceramic substrate 43 can be, for example, SiN, Al ２ O ３ It is constructed using , or AlN. The metal layers 44 and 45 are made of, for example, copper or aluminum. The bonded body 11a has high bonding strength and good conductivity due to the above-described configuration. Furthermore, the bonded body 11a can be manufactured, for example, using the apparatus 30 shown in Figure 4 and under the bonding conditions shown in Figure 5, similar to the bonded body 11 shown in Figure 3.

[0033] [Fourth Example of Joined Body] Figure 7 is a schematic cross-sectional view showing a fourth example of a joined body according to an embodiment of the present invention. In Figure 7, the same components as those in the joined body 10 shown in Figures 1 and 2 are denoted by the same reference numerals, and their detailed descriptions are omitted. The joined body 11b shown in Figure 7 differs from the joined body 10 shown in Figures 1 and 2 in that it has three anisotropic conductive members 12 and three first joined members 14, and the first joined member 14 and anisotropic conductive member 12 are stacked in that order from bottom to top. Also, compared to the joined body 10 shown in Figure 1, the joined body 11b is joined to the anisotropic conductive member 12 via a metal layer 29 provided on the back surface 14b of the first joined member 14. The other components are the same as those in the joined body 10 shown in Figure 1. In the bonded body 11b, it is preferable that the thickness direction Dt of the insulating base material 50 of the anisotropic conductive member 12 and the lamination direction Ds are substantially parallel. The metal layer 29 has the same configuration as the metal layer 29 of the bonded body 11a described above. Therefore, a detailed explanation is omitted. In the bonded body 11b, if the metal layer 29 is formed in a pattern, a resin layer may also be formed. The bonded body 11b has high bonding strength and good conductivity due to the above configuration. The bonded body 11b is configured to have three first members to be joined 14 and three anisotropic conductive members 12, but the number of first members to be joined 14 and anisotropic conductive members 12 is not particularly limited to three each, and depending on the application, the number of first members to be joined 14 and anisotropic conductive members 12 may be two each, or four or more. Furthermore, the joined body 11b can be manufactured, for example, using the apparatus 30 shown in Figure 4, under the joining conditions shown in Figure 5, similar to the joined body 11 shown in Figure 3.

[0034] (Anisotropic Conductive Member) Figure 8 is a schematic cross-sectional view showing an example of an anisotropic conductive member of a laminate according to an embodiment of the present invention. Figure 9 is a schematic plan view showing an example of an anisotropic conductive member of a laminate according to an embodiment of the present invention. Figure 9 is a plan view seen from the surface 50a side of the insulating base material 50 in Figure 8, and shows a state where the resin layer 54 is not provided. The anisotropic conductive member 12 shown in Figure 8 includes an insulating base material 50 having electrical insulating properties, and a plurality of conductive paths 52 that penetrate the insulating base material 50 in the thickness direction Dt, are provided in a state of being electrically insulated from each other, and each have a protruding portion protruding from at least one surface. The anisotropic conductive member 12 further includes a resin layer 54 that covers at least one surface of the insulating base material 50. The anisotropic conductive member 12 has conductivity in the thickness direction Dt of the insulating base material 50. In the joined body 10 described above (see Figure 1), the anisotropic conductive member 12 is laminated with a member to be joined such as the first member to be joined 14 such that the thickness direction Dt of the insulating base material 50 is parallel to the lamination direction Ds of the joined body 10. It should be noted that in the anisotropic conductive member 12, the resin layer 54 is not necessarily required, and a configuration without the resin layer 54 is also acceptable.

[0035] Multiple conductive passages 52 are provided in the insulating substrate 50 in a state where they are electrically insulated from each other. In this case, for example, the insulating substrate 50 has multiple pores 51 that penetrate in the thickness direction Dt. Conductive passages 52 are provided in the multiple pores 51. The conductive passages 52 protrude from the surface 50a of the insulating substrate 50 and have a protruding portion 52a. Also, the conductive passages 52 protrude from the back surface 50b of the insulating substrate 50 and have a protruding portion 52b. In the case of anisotropic conductive members, it is sufficient to have a configuration in which a protruding portion protrudes from at least one surface of the insulating substrate 50, so it is sufficient to have a configuration in which either the protruding portion 52a or the protruding portion 52b is present. However, as described above, in the case of anisotropic conductive members, from the viewpoint of physical bonding with the metal layer and electrical bonding with the metal layer, it is necessary to have a protruding portion on the surface facing the metal layer. The conductive passages 52 only need to protrude from one surface in the thickness direction Dt of the insulating substrate 50. For example, a resin layer 54 is provided on the surface of the insulating substrate 50 on which the conduit 52 protrudes. The resin layer 54 covers the protruding portion 52a of the conduit 52, and the protruding portion 52a is embedded in the resin layer 54. The resin layer 54 also covers the protruding portion 52b of the conduit 52, and the protruding portion 52b is embedded in the resin layer 54. The insulating substrate 50 is made of, for example, an anodic oxide film. The anodic oxide film is formed, for example, by anodizing valve metal. An example of an anodic oxide film of valve metal is an anodic oxide film of aluminum. The surface 50a and the back surface 50b of the insulating substrate 50 are opposing surfaces in the thickness direction Dt of the insulating substrate 50.

[0036] The anisotropic conductive member 12 has anisotropic conductivity and, as described above, has conductivity in the thickness direction Dt, but its conductivity in the direction parallel to the surface 50a of the insulating substrate 50 is sufficiently low. As shown in Figure 9, the anisotropic conductive member 12 has, for example, a rectangular shape in plan view, and for example, all interior angles are 90°. The external shape and size of the anisotropic conductive member 12 are determined as appropriate according to the application, etc. For example, the anisotropic conductive member 12 is joined without the resin layer 54, or with the resin layer 54 present but nothing on the surface 54a.

[0037] Hereinafter, the configuration of the anisotropic conductive member will be described more specifically. The anisotropic conductive member has, for example, the same configuration as the structure described in International Publication No. WO 2022 / 163260, and can be manufactured in the same manner as the above-described structure.

[0038] <Insulating Base Material> The insulating base material 50 is configured to keep a plurality of conductive paths 52 formed of a conductor in a mutually electrically insulated state. As described above, the insulating base material 50 has electrical insulation properties. Further, the insulating base material 50 has a plurality of pores 51 in which the conductive paths 52 are formed. The composition and the like of the insulating base material 50 will be described later. The length of the insulating base material 50 in the thickness direction Dt, that is, the thickness ht of the insulating base material 50 is preferably within the range of 1 to 1000 µm, more preferably within the range of 5 to 500 µm, and still more preferably within the range of 10 to 300 µm. When the thickness ht of the insulating base material 50 falls within this range, the handleability of the insulating base material 50 becomes favorable. From the viewpoint of ease of winding, the thickness ht of the insulating base material 50 is preferably 30 µm or less, and more preferably 5 to 20 µm.

[0039] The thickness of the insulating base material can be measured by cutting the insulating base material in the thickness direction Dt using a focused ion beam (FIB), and acquiring a photographed image of the cross-section at a magnification of 50000 times using a scanning electron microscope (SEM). In the photographed image, the length of the portion corresponding to the thickness of the insulating base material is measured at 10 locations, and the average value of the lengths of the 10 measured locations is obtained. This average value is taken as the thickness of the insulating base material.

[0040] <Average diameter of pores> The average diameter of the pores 51 is preferably 1 μm or less, more preferably 5 to 500 nm, even more preferably 20 to 400 nm, even more preferably 40 to 200 nm, and most preferably 50 to 100 nm. When the average diameter d of the pores 51 is 1 μm or less and within the above range, a guideway 52 having the above average diameter can be obtained. The average diameter of the pores 51 can be measured by taking a picture of the surface of the insulating substrate 50 from directly above at a magnification of 100 to 10000 using a scanning electron microscope (SEM) and obtaining the captured image. In the captured image, at least 20 pores that are connected in an annular shape around the periphery are extracted, their diameters are measured and defined as the aperture diameter, and the average value of these aperture diameters is calculated as the average diameter of the pores. The magnification can be appropriately selected within the above range so as to obtain a captured image in which 20 or more pores can be extracted. The aperture diameter is determined by measuring the maximum distance between the ends of the pore portions. In other words, the shape of the pore opening is not limited to a roughly circular shape. If the shape of the opening is not circular, the maximum distance between the ends of the pore portion is taken as the opening diameter. Therefore, for example, even in the case of a pore that is formed by the integration of two or more pores, it is considered as a single pore, and the maximum distance between the ends of the pore portion is taken as the opening diameter.

[0041] <Conducting passages> As described above, the plurality of conductive passages 52 are provided in an insulating substrate 50, for example, an anodic oxide film, in a state where they are electrically insulated from one another. The plurality of conductive passages 52 are electrically conductive. The conductive passages are made of a conductive material. The conductive material is not particularly limited, but metals are an example. Specific examples of metals that are preferably exemplified are gold (Au), silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), nickel (Ni), zinc (Zn), and cobalt (Co). From the viewpoint of electrical conductivity, copper, gold, aluminum, nickel, and cobalt are preferred, copper and gold are more preferred, and copper is the most preferred. Metals have superior ductility and are easily deformable compared to oxide conductors, and are also easily deformed by compression during joining, so it is preferable to make the conductive passages out of metal. The height of the conductive passages 52 in the thickness direction Dt is preferably 10 to 300 μm, and more preferably 20 to 30 μm.

[0042] <<Shape of the guide channels>> The average diameter d of the guide channels 52 is preferably 1 μm or less, more preferably 5 to 500 nm, even more preferably 20 to 400 nm, even more preferably 40 to 200 nm, and most preferably 50 to 100 nm. The density of the guide channels 52 is 20,000 particles / mm 2 Preferably, the density is 2 million pieces / mm². 2 It is more preferable that the number be greater than or equal to 10 million pieces / mm². 2 It is even more preferable that the number be 50 million / mm² or higher. 2 It is particularly preferable that the value be 100 million pieces / mm². 2 The above is most preferable. Furthermore, the distance p between the centers of each adjacent guideway 52 is preferably 20 nm to 500 nm, more preferably 40 nm to 200 nm, and even more preferably 50 nm to 140 nm.

[0043] The average diameter of the guide channels is determined by taking images of the surface of the insulating substrate from directly above using a scanning electron microscope at a magnification of 100 to 10,000 times. In the images, at least 20 guide channels with a ring-like structure are extracted, their diameters are measured and defined as the aperture diameters, and the average of these aperture diameters is calculated as the average diameter of the guide channels. The magnification can be appropriately selected within the above range to obtain images in which 20 or more guide channels can be extracted. If the shape of the opening is not circular, the maximum distance between the ends of the guide channel portion is defined as the aperture diameter. Therefore, even in the case of a guide channel with a shape in which two or more guide channels are integrated, for example, it is considered as a single guide channel, and the maximum distance between the ends of the guide channel portion is defined as the aperture diameter. The average diameter d of the guide channels 52 is the same as the average diameter of the protrusions. The distance p between the centers of adjacent guide channels 52 is determined by further identifying the center position (not shown) of the identified guide channels in the images of the insulating substrate 50 obtained as described above. The distance between the center positions of adjacent guide channels was determined at 10 locations. This average value was defined as the distance p between the centers of each adjacent conduit 52. The center position is the center position of the region corresponding to the conduit 52 in the captured image described above. In the captured image, a known image analysis method was used to calculate the center position of the region.

[0044] <<Protruding part>> The protruding part is part of the guide passage and is columnar. The protruding part is preferably cylindrical in shape so that the contact area with the object to be joined can be increased. The average protruding length ha of the protruding part 52a and the average length hb of the protruding part 52b are preferably 500 nm to 5 μm, and more preferably 1 μm to 3 μm. If the average protruding length ha and the average length hb are 500 nm to 5 μm, the joining with the member to be joined will be good. The average protruding length ha of the protruding part 52a and the average length hb of the protruding part 52b are the average values ​​obtained by taking a cross-sectional image of the protruding part using a scanning electron microscope as described above, and measuring the height of the protruding part at 10 points based on the cross-sectional image.

[0045] With respect to the guide passage 52, the spacing between adjacent protrusions is preferably 20 nm to 200 nm, and more preferably 40 nm to 100 nm. When the spacing between adjacent protrusions is within the above range, the spacing of the guide passage 52 can be maintained on the surface 50a or back surface 50b of the insulating substrate 50 of the guide passage 52. This suppresses short circuits of the guide passage 52 when joining with a connection target such as a semiconductor device, and further increases the reliability of the joining.

[0046] <<Recesses>> An anisotropic conductive member may have recesses corresponding to the shape of the member to be joined. For example, if the member to be joined has a convex portion, the member will have recesses corresponding to the convex portion. Recesses are formed, for example, by laser processing. A recess is a region in which the thickness in the thickness direction Dt of the insulating substrate 50 is thinner than the back surface 50b of the insulating substrate 50. For example, the recess 13 shown in Figure 2 is a region recessed from the back surface 50b of the insulating substrate 50 toward the front surface 50a.

[0047] <<Resin Layer>> As described above, the resin layer covers at least one of the front and back surfaces of the insulating substrate, protecting the insulating substrate and the conduit. If the conduit has a protrusion, for example, the resin layer will embed the protrusion. That is, the resin layer covers the end of the conduit protruding from the insulating substrate, protecting the protrusion. In order to perform the above functions, it is preferable that the resin layer exhibits fluidity in a temperature range of 50°C to 200°C and hardens at 200°C or higher. The resin layer is a thermoplastic layer composed of, for example, a thermoplastic resin, but the resin layer will be described in detail later. The average thickness hm of the resin layer 54 is greater than the average protrusion length ha and the average length hb of the protrusion 52b, and is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm or less. If the average thickness hm of the resin layer 54 is 10 μm or less as described above, it can adequately protect the protrusion of the conduit 52 and fully exhibit the effect of filling the area around the electrode when joining with a connection target such as a semiconductor device. The average thickness hm of the resin layer 54 is the average distance from the surface 50a of the insulating substrate 50, or the average distance from the back surface 50b of the insulating substrate 50. The average thickness hm of the resin layer 54 described above is determined by cutting the resin layer in the thickness direction Dt of the anisotropic conductive member 12 and acquiring an image of the cross-section using a scanning electron microscope. In the acquired image, the distance from the surface 50a of the insulating substrate 50 corresponding to the resin layer is measured at 10 locations, and the average value of the lengths at the 10 measured locations is calculated. This average value is taken as the average thickness hm of the resin layer 54 on the surface 50a side of the insulating substrate 50. Furthermore, the distance from the back surface 50b of the insulating substrate 50 is measured at 10 locations. The average value of the lengths at the 10 measured locations is calculated. This average value is taken as the average thickness hm of the resin layer 54 on the back surface 50b side of the insulating substrate 50. Note that the scanning electron microscope (SEM) may be a field emission scanning electron microscope (FE-SEM).

[0048] The resin layer may also be composed of the following elements. The composition of the resin layer will be described below. For example, the resin layer may contain a polymer material and may also contain an antioxidant material. Specific examples of resin materials constituting the resin layer include thermoplastic resins such as ethylene copolymers, polyamide resins, polyester resins, polyurethane resins, polyolefin resins, acrylic resins, acrylonitrile resins, and cellulose resins. Polyacrylonitrile can also be used as the resin material constituting the resin layer 54. In addition to the above, the resin layer may contain, for example, a main composition comprising an acrylic polymer, an acrylic monomer, and a maleimide compound as described in International Publication No. 2022 / 163260.

[0049] (Member to be joined) The member to be joined has a resin layer and a metal layer. Preferably, the area ratio of the resin layer to the metal layer of the member to be joined is 5 to 10%, expressed as (area of ​​resin layer) / (area of ​​metal layer). It is preferable that the area ratio (= (area of ​​resin layer) / (area of ​​metal layer)) is within the above range because it increases the bonding strength between the anisotropic conductive member and the member to be joined. The above area ratio is measured, for example, as follows. First, an image is taken from the surface 20a side of the substrate 20 shown in Figure 1. In the image, the region corresponding to the resin layer is identified and the area of ​​the region corresponding to the resin layer is determined. Next, in the image, the region corresponding to the metal layer is identified and the area of ​​the region corresponding to the metal layer is determined. The area of ​​the resin layer and the area of ​​the metal layer are determined in this way. Next, the area ratio is calculated using the area of ​​the region corresponding to the resin layer and the area of ​​the region corresponding to the metal layer. The area ratio of the resin layer to the metal layer is in units of %, and is calculated as: Area ratio of the resin layer to the metal layer (%) = ((area of ​​resin layer) / (area of ​​metal layer)) × 100. The component to be bonded is, for example, a power semiconductor device. Examples of power semiconductor devices include IGBTs (Insulated Gate Bipolar Transistors), SiC-MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), and GaN-HEMTs (High Electron Mobility Transistors). When the component to be bonded is a power semiconductor device, the metal layer is, for example, a source electrode, a drain electrode, or a gate electrode.

[0050] Furthermore, the member to be bonded may have a configuration having a metal layer and a resin layer as described above. Examples include electronic components having a metal layer such as electrodes, terminals, or wiring, and a resin layer, printed wiring boards, printed circuit boards, and TSVs (Through Silicon Vias). Examples of electronic components include semiconductor elements other than the power semiconductor elements described above. Examples of semiconductor elements include logic LSIs (Large Scale Integration), ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), and ASSPs (Application Specific Standard Products). Other examples include microprocessors such as CPUs (Central Processing Units) and GPUs (Graphics Processing Units). Also, examples include memory such as DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), HMC (Hybrid Memory Cube), MRAM (Magnetic RAM), PCM (Phase-Change Memory), ReRAM (Resistive RAM), FeRAM (Ferroelectric RAM), and flash memory.Other examples include LEDs (Light Emitting Diodes), MEMS (Micro Electro Mechanical Systems), GPS (Global Positioning System), FM (Frequency Modulation), NFC (Nearfield Communication), RFEM (RF Expansion Module), MMIC (Monolithic Microwave Integrated Circuit), WLAN (Wireless Local Area Network), discrete elements, BSI (Back Side Illumination), CIS (Contact Image Sensor), camera modules, passive devices, SAW (Surface Acoustic Wave) filters, RF (Radio Frequency) filters, RFIPD (Radio Frequency Integrated Passive Devices), etc. Examples of MEMS include sensors, actuators, and antennas. Sensors include various types of sensors such as acceleration, sound, pressure, and light sensors, as well as gyroscopes. The member to be bonded may be a semiconductor device in which multiple semiconductor elements are stacked and electrically connected, as long as it has a metal layer and a resin layer as described above. A semiconductor device is a collection of multiple semiconductor elements that perform a specific function, but it also includes devices that only transmit electrical signals. A semiconductor device may be, for example, a logic device with a two-dimensional (2D), 2.5-dimensional (2.5D), or three-dimensional (3D) architecture. A semiconductor device may also be, for example, a DRAM stack made by stacking multiple DRAMs, or a configuration in which a DRAM stack and a logic LSI are stacked.

[0051] The present invention is basically configured as described above. Although the joint and method for manufacturing the joint of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various improvements or modifications may be made without departing from the spirit of the present invention.

[0052] The features of the present invention will be further described in detail below with reference to examples. The materials, reagents, amounts and proportions of substances, and procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following examples. In the examples, the joints of Examples 1 to 13 and the joint of Comparative Example 1 were prepared. The strength and anisotropic conductivity of the joints of Examples 1 to 13 and the joint of Comparative Example 1 were evaluated. The evaluation results of strength and anisotropic conductivity are shown in Table 1 below. The anisotropic conductive members of the joints, as well as the bottom tip and top tip, which are the members to be joined and are the targets of the anisotropic conductive members, will be described below.

[0053] [Anisotropic Conductive Material] <Preparation of Aluminum Substrate> A molten metal was prepared using an aluminum alloy containing Si: 0.06 mass%, Fe: 0.30 mass%, Cu: 0.005 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn: 0.001 mass%, and Ti: 0.03 mass%, with the remainder being Al and unavoidable impurities. After molten metal treatment and filtration, an ingot with a thickness of 500 mm and a width of 1200 mm was produced by DC (Direct Chill) casting. Next, the surface was machined to an average thickness of 10 mm using a surface mill, and then it was heated to 550°C for about 5 hours. Once the temperature dropped to 400°C, it was rolled into a 2.7 mm thick sheet using a hot rolling mill. Furthermore, after heat treatment at 500°C using a continuous annealing machine, the material was cold-rolled to a thickness of 1.0 mm to obtain an aluminum substrate conforming to JIS (Japanese Industrial Standards) 1050. After widening this aluminum substrate to 1030 mm, the following treatments were performed.

[0054] <Electrolytic Polishing Treatment> The above-mentioned aluminum substrate was subjected to electrolytic polishing treatment using an electrolytic polishing solution with the following composition under the conditions of a voltage of 25V, a liquid temperature of 65°C, and a liquid flow rate of 3.0 m / min. A carbon electrode was used as the cathode, and a GP0110-30R (manufactured by Takasago Seisakusho Co., Ltd.) was used as the power supply. The flow rate of the electrolyte was measured using a vortex-type flow monitor FLM22-10PCW (manufactured by AS ONE Corporation).

[0055] (Electrolytic polishing solution composition) • 85% by mass phosphoric acid (reagent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 660 mL • Pure water 160 mL • Sulfuric acid 150 mL • Ethylene glycol 30 mL

[0056] <Anodizing Process> Next, the aluminum substrate after electropolishing was subjected to anodizing by a self-regulating method according to the procedure described in Japanese Patent Publication No. 2007-204802. The aluminum substrate after electropolishing was subjected to a pre-anodizing treatment for 5 hours with an electrolyte of 0.50 mol / L oxalic acid under the conditions of a voltage of 40 V, a liquid temperature of 16 °C, and a liquid flow rate of 3.0 m / min. After that, the aluminum substrate after pre-anodizing was subjected to a defilm removal treatment by immersing it in a mixed aqueous solution of 0.2 mol / L anhydrous chromic acid and 0.6 mol / L phosphoric acid (liquid temperature: 50 °C) for 12 hours. After that, a re-anodizing treatment was performed for 3 hours and 45 minutes with an electrolyte of 0.50 mol / L oxalic acid under the conditions of a voltage of 40 V, a liquid temperature of 16 °C, and a liquid flow rate of 3.0 m / min to obtain an anodic oxide film with a thickness of 30 μm. For both the pre-anodic oxidation and re-anodic oxidation processes, a stainless steel electrode was used as the cathode, and a GP0110-30R power supply (manufactured by Takasago Seisakusho Co., Ltd.) was used. A NeoCool BD36 (manufactured by Yamato Scientific Co., Ltd.) was used as the cooling device, and a Pair Stirrer PS-100 (manufactured by EYELA Tokyo Rikakikai Co., Ltd.) was used as the stirring and heating device. Furthermore, the electrolyte flow rate was measured using a vortex flow monitor FLM22-10PCW (manufactured by AS ONE Corporation).

[0057] <Barrier Layer Removal Process> Next, after the anodic oxidation process, an etching treatment was performed by immersing the substrate in an alkaline aqueous solution prepared by dissolving zinc oxide in a sodium hydroxide aqueous solution (50 g / l) at a concentration of 2000 ppm at 30°C for 150 seconds. This removed the barrier layer at the bottom of the micropores of the anodic oxide film and simultaneously deposited zinc on the surface of the exposed aluminum substrate. The average thickness of the anodic oxide film after the barrier layer removal process was 30 μm.

[0058] <Metal Filling Process> Next, electroplating was performed using an aluminum substrate as the cathode and platinum as the cathode. Specifically, a copper plating solution with the following composition was used, and constant current electrolysis was performed to create a metal-filled microstructure in which nickel was filled inside the micropores. Here, constant current electrolysis was performed using a plating device manufactured by Yamamoto Plating Testing Equipment Co., Ltd., with a power supply (HZ-3000) manufactured by Hokuto Denko Co., Ltd., and after confirming the deposition potential by performing cyclic voltammetry in the plating solution, the process was carried out under the following conditions. (Copper plating solution composition and conditions) ・Copper sulfate 100 g / L ・Sulfuric acid 50 g / L ・Hydrochloric acid 15 g / L ・Temperature 25℃ ・Current density 10 A / dm ２

[0059] The surface of the anodic oxide film after filling micropores with metal was observed using a scanning electron microscope (SEM). The presence or absence of metal sealing in 1000 micropores was observed, and the sealing rate (number of sealed micropores / 1000) was calculated to be 98%. Furthermore, the anodic oxide film after filling micropores with metal was machined in the thickness direction using a focused ion beam (FIB), and surface photographs (magnification 50,000x) of the cross-section were taken using a scanning electron microscope (SEM). When the inside of the micropores was examined, it was found that the inside of the sealed micropores was completely filled with metal.

[0060] <Substrate Removal Process> Next, the aluminum substrate was dissolved and removed by immersion in a mixed solution of copper chloride and hydrochloric acid, thereby fabricating a metal-filled microstructure with an average thickness of 30 μm. The diameter of the conduction channels in the fabricated metal-filled microstructure was 60 nm, the pitch between the conduction channels was 100 nm, and the density of the conduction channels was 57.7 million cells / mm². ２ That was the case.

[0061] <Protrusion Process> After the substrate removal process, the metal-filled microstructure was immersed in an aqueous potassium hydroxide (KOH) solution (concentration: 0.01 mol / L), and the immersion time was adjusted so that the height of the protrusions was 1 μm, selectively dissolving the surface of the aluminum anodic oxide film. Then, it was washed with water and dried to protrude the copper cylinders that serve as conductive channels. Similarly, copper cylinders that serve as conductive channels were protruded from the back surface of the aluminum anodic oxide film so that the height of the protrusions was 1 μm. Next, the metal-filled microstructure was processed to a size of 1 mm x 3 mm to produce an anisotropic conductive member.

[0062] [Top Chip and Bottom Chip] A top chip measuring 3 mm x 3 mm was used. The top chip consisted of a SiC substrate with a thickness of 700 μm, on which a wiring layer and a resin layer with a film thickness of 200 nm were formed. The top chip corresponds to the second bonded member 16 shown in Figure 2. The wiring layer was made of gold, and the resin layer was made of polyimide. A bottom chip measuring 6 mm x 6 mm was used. The bottom chip consisted of a SiC substrate with a thickness of 500 μm, on which a resin layer 22 was formed in the pattern shown in Figure 1. The pattern of the resin layer 22 was formed by ultrashort pulse laser processing. The thickness of the resin layer 22 was 200 μm. The resin layer 22 formed a 140 μm x 70 μm section 21b on one side of the SiC substrate. The resin layer 22 surrounded the outer edge of the SiC substrate and the periphery of section 21b, forming a section 21a surrounded by the resin layer 22. The resin layer 22 between section 21a and section 21b has a length of 70 μm. Metal layers with a thickness of 200 nm are formed in sections 21a and 21b on the SiC substrate, respectively. The bottom chip corresponds to the first member to be joined 14 shown in Figure 2. The bottom chip has two metal layers. Of the two metal layers, one metal layer corresponds to the metal layer 24 of the first member to be joined 14, and the other metal layer corresponds to the metal layer 25 of the first member to be joined 14.

[0063] The joining method is described below. Before joining, the anisotropic conductive members were immersed in a citric acid aqueous solution (1% by mass) at a liquid temperature of 20°C for 1 minute, and then rinsed with pure water for 5 minutes. Before joining, the bottom tips with a copper film were immersed in a sulfuric acid aqueous solution (10% by mass) at a liquid temperature of 40°C for 30 seconds. The immersion time was adjusted as appropriate between 5 seconds and 1 minute depending on the state of the surface oxide film formation of the copper film. Before joining, the top and bottom tips with a gold film were cleaned with MEK (methyl ethyl ketone). Before joining, the bottom tips with a tin film were cleaned with pure water.

[0064] A flip-chip bonding apparatus (FC3000 (model) manufactured by Toray Engineering Co., Ltd.) was used for bonding, and the bonding method was flip-chip bonding. The bottom chip was placed on the stage inside the chamber of the bonding apparatus with the SiC substrate facing it. The stage was equipped with a heater. Next, the anisotropic conductive member was placed on the bottom chip. Next, the top chip was placed on the anisotropic conductive member. As a result, the bottom chip, anisotropic conductive member, and top chip were arranged as shown in Figure 1 above.

[0065] Next, in this stacked state, a pressurizing head equipped with a heater was lowered to press the top tip, anisotropic conductive member, and bottom tip from the top tip side. The pressurizing head pressurized the top tip, anisotropic conductive member, and bottom tip to a preset pressure as shown in Figure 5. At this time, for example, nitrogen gas was supplied into the chamber to lower the oxygen concentration inside the chamber. When the oxygen concentration inside the chamber was below the preset concentration as shown in Figure 5, the heater on the stage (not shown) and the heater on the pressurizing head (not shown) were heated to heat the anisotropic conductive member to a preset bonding temperature (see Figure 5). Bonding began when the bonding temperature was reached. The bonding temperature was maintained for a preset time. After the preset time for the bonding temperature had elapsed, the supply of nitrogen gas into the chamber was stopped, and the oxygen concentration inside the chamber was increased as shown in Figure 5. After the preset time for the bonding temperature had elapsed, the heating of the heater on the stage and the heater on the pressurizing head was stopped. Thereafter, as shown in Figure 5, the pressure was maintained, that is, the pressurized state was maintained, and the chamber was cooled to room temperature, and the pressurizing head was raised to release the pressure. A joint was obtained in this manner. Note that if the top tip and bottom tip (members to be joined) and the anisotropic conductive member (joining member) are pressurized during the heating and cooling processes described above, "Yes" is indicated in the "Pressure Cooling" column of Table 1 below. If no pressure is applied, "No" is indicated in the "Pressure Cooling" column of Table 1 below.

[0066] In the bonding process, the bonding temperature was set to 290°C, and the holding time at the bonding temperature was set to 250 seconds. The cooling time was set to 10 seconds. The bonding temperature was set to the set temperature of the stage heater and the pressure head heater. The set bonding temperature was achieved by making the set temperatures of the stage heater and the pressure head heater the same. The bonding temperature was adjusted by changing the set temperatures of the stage heater and the pressure head heater. The bonding pressure was the value obtained by dividing the pressurized load on one top tip by the area of ​​one top tip. The bonding pressure was adjusted by adjusting the pressurized load on one top tip. The oxygen concentration was measured using an oxygen concentration meter (manufactured by Toray Engineering D Solutions Co., Ltd.).

[0067] (Example 1) The resin layer of the bottom tip was made of polyimide, and the metal layer was made of gold (Au). The bottom tip had a convex portion, and the anisotropic conductive member had a recess corresponding to the convex portion. The recess was formed by laser processing. The size of the recess was 1.2 mm in length in one direction and 12 μm in depth. In the region where the bottom tip and the anisotropic conductive member overlapped, the area ratio of the resin layer to the metal layer was 10%. The oxygen concentration at the time of bonding was 10 ppm. (Example 2) Example 2 differed from Example 1 in that the resin layer was made of polybenzoxazole (PBO), and otherwise the bonded body was obtained in the same manner as in Example 1.

[0068] (Example 3) Example 3 differs from Example 1 in that no pressure was applied during cooling, but otherwise the bonded body was obtained in the same manner as in Example 1. In Example 3, after a predetermined time had elapsed for the bonding temperature during bonding, the heating of the stage heater and the pressure head heater was stopped, the pressure head was raised to release the pressure, and the bonded body was obtained by cooling to room temperature without maintaining the pressurized state. (Example 4) Example 4 differs from Example 3 in that the resin layer was composed of polybenzoxazole (PBO), but otherwise the bonded body was obtained in the same manner as in Example 3.

[0069] (Example 5) Example 5 differs from Example 1 in that the resin layer is made of epoxy resin, and otherwise the bonded body was obtained in the same manner as Example 1. (Example 6) Example 6 differs from Example 1 in that the metal layer of the bottom tip is made of silver (Ag), and otherwise the bonded body was obtained in the same manner as Example 1. (Example 7) Example 7 differs from Example 1 in that the metal layer of the bottom tip is made of copper (Cu), and otherwise the bonded body was obtained in the same manner as Example 1.

[0070] (Example 8) Example 8 differs from Example 1 in that the metal layer of the bottom tip is made of an Al-Si alloy, and otherwise the bonded body was obtained in the same manner as in Example 1. (Example 9) Example 9 is an example in which the structure of the bonded body is as shown in Figure 7, in which the bottom tip and anisotropic conductive members are alternately stacked, and there are three layers of anisotropic conductive members. The bonded body of Example 9 can be obtained in the same manner as in Example 1.

[0071] (Example 10) Example 10 differs from Example 1 in that the metal layer of the bottom tip is made of Sn, and otherwise the bonded body was obtained in the same manner as in Example 1.

[0072] (Example 11) Example 11 differs from Example 1 in that there is no protrusion on the bottom tip and no recess on the anisotropic conductive member, but otherwise the bonded body was obtained in the same manner as Example 1. (Example 12) Example 12 differs from Example 1 in that the area ratio was set to 30%, but otherwise the bonded body was obtained in the same manner as Example 1. (Example 13) Example 13 differs from Example 1 in that the area ratio was set to 30% and the oxygen concentration at the time of bonding was 100 ppm, but otherwise the bonded body was obtained in the same manner as Example 1. The oxygen concentration at the time of bonding was set to 100 ppm by adjusting the amount of nitrogen gas supplied.

[0073] (Comparative Example 1) Comparative Example 1 differs from Example 1 in that the resin layer is made of epoxy resin and no pressure is applied during cooling, but otherwise the bonded body is obtained in the same manner as in Example 1. In Comparative Example 1, after a predetermined time has elapsed for the bonding temperature during bonding, the heating of the stage heater and the pressure head heater is stopped, the pressure head is raised to release the pressure, and the bonded body is obtained by cooling to room temperature without maintaining the pressurized state and cooling to room temperature.

[0074] The following describes the strength evaluation and anisotropic conductivity evaluation performed on the joint. (Strength Evaluation) Strength was evaluated using shear strength. Shear strength was evaluated by measuring the shear strength between the bottom tip and the anisotropic conductive material using a die shear device (Stellar 4000 (device name) manufactured by Nordson Advanced Technologies, Inc.). Shear strength is determined from the obtained fracture load and the area of ​​the anisotropic conductive material. Shear strength was evaluated according to the following evaluation criteria. (Evaluation Criteria) A: 40 MPa ≤ Shear Strength B: 30 MPa ≤ Shear Strength < 40 MPa C: Shear Strength < 30 MPa

[0075] (Evaluation of Anisotropic Conductivity) Anisotropic conductivity was evaluated as follows: The wiring pattern of the top chip was pre-set so that each metal layer of the bottom chip, corresponding to the metal layers 24 and 25 of the first bonded member 14 shown in Figure 1, could be electrically connected to the top chip. Anisotropic conductivity was evaluated by attempting to measure the electrical resistance between the wiring connected to one metal layer of the bottom chip and the wiring connected to the other metal layer of the bottom chip using a tester. Anisotropic conductivity was evaluated based on the obtained electrical resistance according to the following evaluation criteria: (Evaluation Criteria) A: Electrical resistance of 20 MΩ or more B: Electrical resistance of 10 MΩ or more and less than 20 MΩ C: Electrical resistance of less than 10 MΩ

[0076]

[0077] As shown in Table 1, Examples 1 to 13 exhibited superior strength and anisotropic conductivity compared to Comparative Example 1. From Examples 1 and 11, it can be said that higher strength was achieved when the joined member had protrusions and the anisotropic conductive member had corresponding recesses. Furthermore, from Examples 1, 6 to 8 and 10, it can be predicted that higher strength is achieved when the metal layer contains Cu, Au, Ag, or Al.

[0078] 10, 11, 11a, 11b Joint 12 Anisotropic conductive member 12a, 20a Surface 12b, 14b, 26b Back surface 13 Recess 14 First member to be joined 16 Second member to be joined 20 Substrate 20d, 20e Side 21a, 21b Section 22 Resin layer 23 Protrusion 24, 25, 29 Metal layer 26 Substrate 27 Wiring layer 30 Device 32 Stage 32a Surface 33 Heater 34 Chamber 34a Interior 35 Pressurized head 36 Gas supply unit 38 Concentration meter 40 Anisotropic conductive member 40b, 43b, 50b Back surface 42 Insulating heat dissipation circuit board 43 Ceramic substrate 43a, 44a, 45a, 50a, 54a Surface 44, 45 Metal layer 50 Insulating substrate 51 Pore 52 Conductor 52a, 52b Protrusion 54 Resin layer D Direction Ds Lamination direction Dt Thickness direction d Average diameter hm Average thickness ht Thickness p Distance between centers

Claims

1. A joint comprising an insulating substrate having electrical insulating properties, an anisotropic conductive member having a plurality of conductive passages provided through the thickness direction of the insulating substrate and having protrusions protruding from at least one surface of the insulating substrate, and a member to be joined to the anisotropic conductive member, wherein the member to be joined has a resin layer and a metal layer, and the resin layer is polyimide or polybenzoxazole.

2. The joint according to claim 1, wherein the member to be joined has a protrusion, and the anisotropic conductive member has a recess corresponding to the protrusion.

3. The joined body according to claim 1, wherein the joined member has an area ratio of the resin layer to the metal layer, expressed as the area of ​​the resin layer / the area of ​​the metal layer, which is 5 to 10%.

4. The joint according to claim 1, wherein a plurality of the anisotropic conductive members are arranged via the member to be joined in the stacking direction between the anisotropic conductive members and the member to be joined.

5. The joint according to claim 1, wherein the metal layer of the member to be joined comprises Cu, Au, Ag, or Al.

6. The bonded body according to claim 1, wherein the member to be bonded is a power semiconductor element.

7. A method for manufacturing a joined body, comprising a joining step of joining a member to be joined and a joining member, wherein the joining step involves pressurizing the member to be joined and the joining member when they are heated and when they are cooled.

8. The method for manufacturing a joined body according to claim 7, wherein the oxygen concentration at the time of joining the member to be joined and the joining member is 40 ppm or less.

9. The method for manufacturing a bonded body according to claim 7 or 8, wherein the bonding member is an anisotropic conductive member having an insulating substrate having electrical insulating properties and a plurality of conductive passages provided that penetrate the insulating substrate in the thickness direction and have protrusions that protrude from at least one surface of the insulating substrate, and the member to be bonded has a resin layer and a metal layer, and the resin layer is polyimide or polybenzoxazole.

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