Circuit module and method for manufacturing circuit module

Abstract

According to the present invention, a mounting electrode is located on a positive principal surface of a resin layer located in the most positive Z-axis direction among a plurality of resin layers.　An inner conductor layer overlaps the mounting electrode as seen in the Z-axis direction.　The positive Z-axis end of a first interlayer connecting conductor is in contact with the mounting electrode.　The negative Z-axis end of the first interlayer connecting conductor is in contact with the inner conductor layer.　An article comprises a connecting member bonded to the mounting electrode.　The first interlayer connecting conductor includes first and second areas.　The first and second areas are arranged in that order in the negative Z-axis direction.　The material of the first area is the same as the material of the mounting electrode.　The Young's modulus of the second area is lower than the Young's modulus of the first area.

Description

Circuit module and method for manufacturing the circuit module

[0001] The present invention relates to an article and a circuit module comprising a circuit board.

[0002] A known example of a conventional invention relating to a circuit module is a semiconductor device described in Patent Document 1. The semiconductor device includes an IC chip and a multilayer wiring substrate. A plurality of IC connection terminals are provided on an upper main surface of the multilayer wiring substrate. A plurality of via connection terminals and a plurality of support vias are provided inside the multilayer wiring substrate. Each of the plurality of support vias connects a plurality of IC connection terminals to a plurality of via connection terminals.

[0003] The IC chip also has a plurality of solder bumps, each of which is bonded to a corresponding one of the IC connection terminals.

[0004] JP 2008-243884 A

[0005] In the field of semiconductor devices described in Patent Document 1, multiple solder bumps and multiple IC connection terminals are sometimes joined using ultrasonic bonding technology. In this case, ultrasonic vibrations are transmitted to the multiple IC connection terminals and multiple support vias. As a result, vibrations are applied to the boundaries between the multiple support vias and the multiple via connection terminals, which may cause damage to these connections.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a circuit module and a method for manufacturing the circuit module that can prevent damage from occurring in the connection portion between the interlayer connection conductor and the internal conductor layer.

[0007] a first interlayer connection conductor penetrating the resin layers in the Z-axis direction, the first interlayer connection conductor having an end in the Z-axis direction in contact with the mounting electrode, and an end in the Z-axis direction in contact with the internal conductor layer; and a connecting member solid-state welded to the mounting electrode, the first interlayer connection conductor including a first region and a second region, the first region and the second region being aligned in this order in the Z-axis direction. The Young's modulus of the second region is lower than the Young's modulus of the first region.

[0008] a third interlayer connection conductor penetrating the resin layer in the Z-axis direction, wherein an end of the third interlayer connection conductor in the positive Z-axis direction is in contact with the mounting electrode and an end of the third interlayer connection conductor in the negative Z-axis direction is in contact with the internal conductor layer; and a fourth interlayer connection conductor penetrating the resin layer in the Z-axis direction and overlapping the mounting electrode in the Z-axis direction, wherein an end of the fourth interlayer connection conductor in the positive Z-axis direction is in contact with the internal conductor layer. The article comprises a connection member solid-state welded to the mounting electrode, the fourth interlayer connection conductor includes a third region and a fourth region aligned in the Z-axis direction, the material of the third interlayer connection conductor and the material of the third region are the same as the material of the mounting electrode, and the Young's modulus of the fourth region is lower than the Young's modulus of the third region.

[0009] The circuit module according to the present invention can prevent damage to the connection portion between the interlayer connection conductor and the internal conductor layer.

[0010] Fig. 1 is a cross-sectional view of a circuit module 10. Fig. 2 is a cross-sectional view of a circuit module 10a. Fig. 3 is a cross-sectional view of a circuit module 10b. Fig. 4 is a cross-sectional view of a circuit module 10c.

[0011] EMBODIMENTS [Structure of Circuit Module] The structure of a circuit module 10 according to an embodiment of the present invention will be described below with reference to the drawings. FIG.

[0012] In this specification, directions are defined as follows: The stacking direction of the laminate 12 is defined as the up-down direction. The up-down direction also coincides with the Z-axis direction. The up-down direction is the positive direction of the Z-axis. The down-down direction is the negative direction of the Z-axis. Directions perpendicular to the up-down direction are defined as the left-right direction and the front-rear direction. The left-right direction is perpendicular to the front-rear direction. Note that the up-down direction and the down-down direction in the up-down direction may be interchanged, the left-right direction and the right-left direction in the left-right direction may be interchanged, and the front-rear direction and the rear-rear direction in the front-rear direction may be interchanged.

[0013] The circuit module 10 is used in, for example, a wireless communication terminal such as a smartphone, etc. The circuit module 10 includes a circuit board 11 and an article 100.

[0014] The circuit board 11 transmits high-frequency signals and includes a laminate 12, a protective layer 16, conductor layers 18a to 18c and 20a to 20c, internal conductor layers 19a to 19f, first interlayer connection conductors V1a and V1b, interlayer connection conductors v1, v3a to v3c, and second interlayer connection conductors v2a to v2f.

[0015] The laminate 12 has a plate shape with upper and lower main surfaces. The laminate 12 has a structure in which resin layers 14a to 14d, each having an upper main surface (a front main surface located in the positive direction of the Z axis) and a lower main surface, are stacked in the vertical direction (Z axis direction). The resin layers 14a to 14d are arranged in this order from top to bottom. The resin layers 14a to 14d have a rectangular shape when viewed in the vertical direction. The resin layers 14a to 14d are made of resin. The resin layers 14a to 14d are made of, for example, a thermoplastic resin. The thermoplastic resin is, for example, a liquid crystal polymer. This gives the laminate 12 flexibility.

[0016] The conductor layers 18a to 18c are provided on the laminate 12. The conductor layers 18a to 18c are located on the upper main surface (front main surface) of the resin layer 14a, which is located at the top (most positive direction on the Z axis) of the resin layers 14a to 14d. The conductor layers 18a to 18c also have mounting electrodes E1 to E3. Therefore, the mounting electrodes E1 to E3 are located on the upper main surface (front main surface) of the resin layer 14a, which is located at the top (most positive direction on the Z axis) of the resin layers 14a to 14d. The mounting electrodes E1 to E3 are portions of the conductor layers 18a to 18c that are exposed from the protective layer 16, which will be described later. The mounting electrodes E1 to E3 have a rectangular shape when viewed in the vertical direction.

[0017] The conductor layers 18a to 18c are arranged in this order from left to right. The conductor layer 18a extends in the left-right direction. The mounting electrode E1 is located at the right end of the conductor layer 18a. The conductor layer 18b has a square shape. The mounting electrode E2 is located in the center of the conductor layer 18b. The conductor layer 18c extends in the left-right direction. The mounting electrode E3 is located at the left end of the conductor layer 18c.

[0018] The internal conductor layers 19a to 19c are provided in the laminate 12. The internal conductor layers 19a to 19c are located on the upper main surface of the resin layer 14b. The internal conductor layers 19a to 19c are arranged in this order from left to right. The internal conductor layers 19a to 19c extend in the left-right direction. Furthermore, the internal conductor layers 19a and 19b overlap with the mounting electrodes E1 and E2, respectively, when viewed in the vertical direction (Z-axis direction). In this embodiment, the right end of the internal conductor layer 19a overlaps with the mounting electrode E1 when viewed in the vertical direction. The left end of the internal conductor layer 19b overlaps with the mounting electrode E2 when viewed in the vertical direction.

[0019] The internal conductor layers 19d to 19f are provided in the laminate 12. The internal conductor layers 19d to 19f are located on the lower main surface of the resin layer 14c. The internal conductor layers 19d to 19f are arranged in this order from left to right.

[0020] The conductor layers 20a to 20c are provided on the laminate 12. The conductor layers 20a to 20c are located on the lower main surface of the resin layer 14d. The conductor layers 20a to 20c are arranged in this order from left to right. The conductor layers 20a to 20c have a rectangular shape when viewed in the vertical direction. The conductor layers 20a to 20c are, for example, external electrodes.

[0021] The conductor layers 18a to 18c, 20a to 20c, and internal conductor layers 19a to 19f are formed by patterning metal foil attached to the upper main surfaces of the resin layers 14a and 14b and the lower main surfaces of the resin layers 14c and 14d. The metal foil is, for example, copper foil.

[0022] The mounting electrodes E1 to E3 have a structure in which the surface of the copper foil is plated with nickel and gold. Thus, the surface material of the mounting electrodes E1 to E3 is gold.

[0023] The protective layer 16 covers substantially the entire front principal surface (upper principal surface) of the resin layer 14a, which is located at the top (positive direction of the Z axis) among the resin layers 14a to 14d. As a result, the protective layer 16 protects the conductor layers 18a to 18c. However, the mounting electrodes E1 to E3 are not covered by the protective layer 16. Furthermore, the protective layer 16 is not a part of the laminate 12. No conductor layer is provided on the upper principal surface of the protective layer 16.

[0024] The first interlayer connection conductors V1a and V1b are provided in the laminate 12. In this embodiment, the first interlayer connection conductors V1a and V1b penetrate the resin layer 14a in the vertical direction (Z-axis direction). When viewed in the vertical direction, the first interlayer connection conductor V1a overlaps with the mounting electrode E1 and the right end of the internal conductor layer 19a. Therefore, the upper end (the end in the positive direction of the Z-axis) of the first interlayer connection conductor V1a contacts the mounting electrode E1. The lower end (the end in the negative direction of the Z-axis) of the first interlayer connection conductor V1a contacts the internal conductor layer 19a. Furthermore, when viewed in the vertical direction, the first interlayer connection conductor V1b overlaps with the mounting electrode E2 and the left end of the internal conductor layer 19b. Therefore, the upper end (the end in the positive direction of the Z-axis) of the first interlayer connection conductor V1b contacts the mounting electrode E2. The lower end (the end in the negative direction of the Z axis) of the first interlayer connection conductor V1b is in contact with the internal conductor layer 19b.

[0025] The first interlayer connection conductors V1a and V1b have a shape in which the area of ​​a cross section perpendicular to the up-down direction decreases from bottom to top. Specifically, the first interlayer connection conductors V1a and V1b have a truncated cone shape. The area of ​​the upper ends of the first interlayer connection conductors V1a and V1b is smaller than the area of ​​the lower ends of the first interlayer connection conductors V1a and V1b.

[0026] Each of the first interlayer connection conductors V1a and V1b includes a first region A1 and a second region A2. The first region A1 and the second region A2 are arranged in this order downward (negative direction of the Z axis). Therefore, the second region A2 is located below the first region A1 (negative direction of the Z axis). The volume of the first region A1 is 30% or more of the volume of the first interlayer connection conductors V1a and V1b. The Young's modulus of the second region A2 is lower than that of the first region A1. As a result, the Young's modulus of the lower half of the first interlayer connection conductors V1a and V1b is different from that of the upper half of the first interlayer connection conductors V1a and V1b. Furthermore, the second region A2 has a lower heat conductivity than that of the first region A1. The material of the first region A1 is the same as the material of the mounting electrodes E1 and E2. Therefore, the material of the first region A1 and the materials of the mounting electrodes E1, E2 are, for example, copper, aluminum, or silver. The material of such a second region A2 is an alloy whose main component is tin. The alloy whose main component is tin is, for example, an alloy of tin and copper or an alloy of tin and silver. The second region A2 is formed by sintering a conductive paste, which is a mixture of metal powder and resin.

[0027] The interlayer connection conductor v1 is provided in the laminate 12. In this embodiment, the interlayer connection conductor v1 penetrates the resin layer 14a in the vertical direction (Z-axis direction). The upper end of the interlayer connection conductor v1 contacts the right end of the conductor layer 18c. The lower end of the interlayer connection conductor v1 contacts the left end of the internal conductor layer 19c. The structure of the interlayer connection conductor v1 is the same as that of the first interlayer connection conductors V1a and V1b, so a description thereof will be omitted.

[0028] The second interlayer connecting conductors v2a to v2c are located below the first interlayer connecting conductors V1a and V1b (in the negative direction of the Z axis). The second interlayer connecting conductors v2a to v2c penetrate the resin layer 14b in the up-and-down direction (the Z axis direction). The upper end of the second interlayer connecting conductor v2a is in contact with the left end of the internal conductor layer 19a. The upper end of the second interlayer connecting conductor v2b is in contact with the right end of the internal conductor layer 19b. The upper end of the second interlayer connecting conductor v2c is in contact with the right end of the internal conductor layer 19c.

[0029] The second interlayer connection conductors v2a to v2c have a shape in which the area of ​​the cross section perpendicular to the up-down direction decreases from bottom to top. Specifically, the second interlayer connection conductors v2a to v2c have a truncated cone shape. The area of ​​the upper ends of the second interlayer connection conductors v2a to v2c is smaller than the area of ​​the lower ends of the second interlayer connection conductors v2a to v2c.

[0030] The second interlayer connecting conductors v2d to v2f are located below the first interlayer connecting conductors V1a and V1b (in the negative direction of the Z axis). The second interlayer connecting conductors v2d to v2f penetrate the resin layer 14c in the up-down direction (Z axis direction). The upper end of the second interlayer connecting conductor v2d is in contact with the second interlayer connecting conductor v2a. The lower end of the second interlayer connecting conductor v2d is in contact with the internal conductor layer 19d. The upper end of the second interlayer connecting conductor v2e is in contact with the second interlayer connecting conductor v2b. The lower end of the second interlayer connecting conductor v2e is in contact with the right end of the internal conductor layer 19e. The upper end of the second interlayer connecting conductor v2f is in contact with the second interlayer connecting conductor v2c. The lower end of the second interlayer connecting conductor v2f is in contact with the internal conductor layer 19f.

[0031] The second interlayer connection conductors v2d to v2f have a shape in which the area of ​​the cross section perpendicular to the up-down direction decreases from top to bottom. Specifically, the second interlayer connection conductors v2d to v2f have a truncated cone shape. The area of ​​the lower ends of the second interlayer connection conductors v2d to v2f is smaller than the area of ​​the upper ends of the second interlayer connection conductors v2d to v2f.

[0032] The Young's modulus of the second interlayer connection conductors v2a to v2f described above is lower than that of the first region A1. The Young's modulus of the second interlayer connection conductors v2a to v2f is equal to that of the second region A2. The material of such second interlayer connection conductors v2a to v2f is an alloy containing tin as its main component. Examples of alloys containing tin as its main component include an alloy of tin and copper, and an alloy of tin and silver. The second interlayer connection conductors v2a to v2f are formed by sintering a conductive paste, which is a mixture of metal powder and resin.

[0033] The interlayer connection conductors v3a to v3c are provided in the laminate 12. In this embodiment, the interlayer connection conductors v3a to v3c penetrate the resin layer 14d in the vertical direction. The upper end of the interlayer connection conductor v3a is in contact with the internal conductor layer 19d. The lower end of the interlayer connection conductor v3a is in contact with the conductor layer 20a. The upper end of the interlayer connection conductor v3b is in contact with the left end of the internal conductor layer 19e. The lower end of the interlayer connection conductor v3b is in contact with the conductor layer 20b. The upper end of the interlayer connection conductor v3c is in contact with the internal conductor layer 19f. The lower end of the interlayer connection conductor v3c is in contact with the conductor layer 20c.

[0034] The interlayer connection conductors v3a to v3c have a shape in which the area of ​​the cross section perpendicular to the up-down direction decreases from top to bottom. Specifically, the interlayer connection conductors v3a to v3c have a truncated cone shape. The area of ​​the lower ends of the interlayer connection conductors v3a to v3c is smaller than the area of ​​the upper ends of the interlayer connection conductors v3a to v3c.

[0035] Each of the interlayer connection conductors v3a to v3c includes a first region A1 and a second region A2. The second region A2 is located above the first region A1. The structures of the first region A1 and the second region A2 of the interlayer connection conductors v3a to v3c are the same as the structures of the first region A1 and the second region A2 of the first interlayer connection conductors V1a and V1b, so a description thereof will be omitted.

[0036] In the process of forming the first interlayer connection conductors V1a, V1b and the interlayer connection conductors v1, v3a to v3c, through-holes are formed that penetrate the resin layers 14a, 14d in the vertical direction (Z-axis direction). The through-holes are then plated to form the first regions A1. After the first regions A1 are formed, the through-holes are filled with a conductive paste, which is then solidified by heating to form the second regions A2.

[0037] The item 100 is mounted on mounting electrodes E1 to E3 of a circuit board 11. The item 100 is an element that generates heat during operation. The item 100 is, for example, an IC (Integrated Circuit). The item 100 is, for example, an RFIC (Radio Frequency Integrated Circuit), a CPU (Central Processing Unit), a power supply IC, or the like. The item 100 includes an item main body 102 and connection members B1 to B3. The item main body 102 has a rectangular parallelepiped shape. The connection members B1 to B3 are located on the underside of the item main body 102. The connection members B1 to B3 are arranged in this order from left to right. The connection members B1 to B3 are solid-state welded to the mounting electrodes E1 to E3, respectively. Solid-state bonding is bonding in which a bonding boundary is formed by contact between the solid phases of the connection members B1 to B3 and the solid phases of the mounting electrodes E1 to E3. In solid-state bonding, two metals are joined without a low-melting-point metal.

[0038] The connection members B1 to B3 described above are gold bumps. Therefore, the surface material of the connection members B1 to B3 is gold. In this embodiment, the entire material of the connection members B1 to B3 is gold. Each of the connection members B1 to B3 is then bonded to the mounting electrodes E1 to E3 using ultrasonic bonding technology. During ultrasonic bonding, a portion of the gold of the connection members B1 to B3 and a portion of the gold of the mounting electrodes E1 to E3 melts and then solidifies. In this way, each of the connection members B1 to B3 is bonded to the mounting electrodes E1 to E3.

[0039] [Effects] (a) The circuit module 10 can prevent damage to the connection between the first interlayer connection conductor V1a and the internal conductor layer 19a. More specifically, the surface of the connection member B1 is made of gold. Therefore, the connection member B1 is bonded to the mounting electrode E1 using ultrasonic bonding technology. For the connection member B1 to be firmly bonded to the mounting electrode E1, the mounting electrode E1 only needs to be supported by the hard first interlayer connection conductor V1a. For example, the material of the first interlayer connection conductor V1a may be the same as the material of the mounting electrode E1. This allows ultrasonic vibrations to be efficiently transmitted to the connection member B1 and the mounting electrode E1. As a result, the connection member B1 is firmly bonded to the mounting electrode E1.

[0040] However, if the first interlayer connection conductor V1a is too hard, damage may occur at the connection between the first interlayer connection conductor V1a and the internal conductor layer 19a. More specifically, the upper end of the first interlayer connection conductor V1a is in contact with the mounting electrode E1. The lower end of the first interlayer connection conductor V1a is in contact with the internal conductor layer 19a. Therefore, the ultrasonic vibration is transmitted to the first interlayer connection conductor V1a and the internal conductor layer 19a via the mounting electrode E1. If the first interlayer connection conductor V1a is too hard, the ultrasonic vibration is likely to be applied to the joint between the first interlayer connection conductor V1a and the internal conductor layer 19a.

[0041] Therefore, the first interlayer connection conductor V1a includes a first region A1 and a second region A2. The first region A1 and the second region A2 are arranged downward in this order. The Young's modulus of the second region A2 is lower than that of the first region A1. As a result, the mounting electrode E1 is supported by the harder first region A1. Therefore, the connecting member B1 is firmly joined to the mounting electrode E1. Meanwhile, the soft second region A2 exists between the mounting electrode E1 and the internal conductor layer 19a. Therefore, ultrasonic vibrations are less likely to be transmitted from the first interlayer connection conductor V1a to the internal conductor layer 19a. Therefore, the circuit module 10 can prevent damage to the connection between the first interlayer connection conductor V1a and the internal conductor layer 19a. For the same reason, the circuit module 10 can prevent damage to the connection between the first interlayer connection conductor V1b and the internal conductor layer 19b.

[0042] (b) In the circuit module 10, the volume of the first region A1 is 30% or more of the volume of the first interlayer connection conductor V1a. This makes the first interlayer connection conductor V1a hard, and the mounting electrode E1 is supported by the hard first interlayer connection conductor V1a. As a result, ultrasonic vibrations are efficiently transmitted to the connection member B1 and the mounting electrode E1. As a result, the connection member B1 is firmly joined to the mounting electrode E1.

[0043] (c) In the circuit module 10, ultrasonic vibrations are suppressed from being transmitted inside the laminate 12. More specifically, the second interlayer connection conductors v2a to v2f are located below the first interlayer connection conductors V1a and V1b (in the negative direction of the Z axis). The Young's modulus of the second interlayer connection conductors v2a to v2f is lower than the Young's modulus of the first region A1. This makes it difficult for ultrasonic vibrations to propagate inside the laminate 12 via the second interlayer connection conductors v2a to v2f. As a result, in the circuit module 10, ultrasonic vibrations are suppressed from being transmitted inside the laminate 12. As a result, disconnections are suppressed inside the laminate 12 of the circuit module 10.

[0044] (d) In the circuit module 10, the occurrence of warping in the circuit board 11 is suppressed. More specifically, the first interlayer connection conductors V1a, V1b and interlayer connection conductor v1 penetrate the resin layer 14a in the vertical direction. The interlayer connection conductors v3a to v3c penetrate the resin layer 14d in the vertical direction. The first interlayer connection conductors V1a, V1b and interlayer connection conductors v1, v3a to v3c include a first region A1 and a second region A2. This makes the circuit board 11 closer to a vertically symmetrical structure. Therefore, the linear expansion coefficient near the upper main surface of the circuit board 11 approaches the linear expansion coefficient near the lower main surface of the circuit board 11. As described above, in the circuit module 10, the occurrence of warping in the circuit board 11 is suppressed.

[0045] (e) In the circuit module 10, the resin layers 14a to 14d are made of a thermoplastic resin. Therefore, the resin layers 14a to 14d are thermocompression-bonded to form the laminate 12. Furthermore, during the thermocompression-bonding, the second regions A2 of the first interlayer connection conductors V1a and V1b, the second regions A2 of the interlayer connection conductors v1, v3a to v3c, and the second interlayer connection conductors v2a to v2f can be hardened.

[0046] (First Modification) The structure of a circuit module 10a according to a first modification will be described below with reference to the drawings. Fig. 2 is a cross-sectional view of the circuit module 10a.

[0047] The circuit module 10a differs from the circuit module 10 in the structure of the second interlayer connection conductors v2a to v2f. More specifically, the second interlayer connection conductors v2a to v2f include a first region A1 and a second region A2. In the second interlayer connection conductors v2a to v2c, the first region A1 is located above the second region A2. In the second interlayer connection conductors v2d to v2f, the second region A2 is located above the first region A1. The other structure of the circuit module 10a is the same as that of the circuit module 10, so a description thereof will be omitted. The circuit module 10a can achieve the effects (a), (b), (d), and (e).

[0048] (f) In the circuit module 10a, the second interlayer connection conductors v2a to v2f become hard, which in turn hardens the circuit board 11a, making it easier for ultrasonic vibrations to be transmitted through the circuit board 11a, and thus the connection members B1 to B3 are firmly joined to the mounting electrodes E1 to E3, respectively.

[0049] (g) According to the circuit module 10a, all of the first interlayer connection conductors V1a, V1b, interlayer connection conductors v1, v3a to v3c, and second interlayer connection conductors v2a to v2f include the first region A1 and the second region A2. Therefore, all of the first interlayer connection conductors V1a, V1b, interlayer connection conductors v1, v3a to v3c, and second interlayer connection conductors v2a to v2f can be formed by the same method.

[0050] (Second Modification) The structure of a circuit module 10b according to a second modification will be described below with reference to the drawings. Fig. 3 is a cross-sectional view of the circuit module 10b.

[0051] The circuit module 10b differs from the circuit module 10 in the structure of the article 100. More specifically, the connection members B1 and B3 are gold wires. The remaining structure of the circuit module 10b is the same as that of the circuit module 10, and therefore will not be described further. The circuit module 10b can achieve the effects (a) to (e). Furthermore, when connecting the connection members B1 and B3 to the mounting electrodes E1 and E3, respectively, the connection member B1 is first connected to the mounting electrode E1 using ultrasonic bonding technology, and then the connection member B3 is connected to the mounting electrode E3 using ultrasonic bonding technology. In this way, the connection members B1 and B3 are connected to the mounting electrodes E1 and E3 in multiple steps, thereby ensuring a more reliable connection of the connection members B1 and B3 to the mounting electrodes E1 and E3.

[0052] (Third Modification) The structure of a circuit module 10c according to a third modification will be described below with reference to the drawings. Fig. 4 is a cross-sectional view of the circuit module 10c.

[0053] The circuit module 10c differs from the circuit module 10 in that it includes third interlayer connecting conductors v13a-v13c and a fourth interlayer connecting conductor V4. The third interlayer connecting conductors v13a-v13c penetrate the resin layer 14a in the up-down direction (Z-axis direction). The upper end (end in the positive direction of the Z-axis) of the third interlayer connecting conductor v13a contacts the mounting electrode E1. The lower end (end in the negative direction of the Z-axis) of the third interlayer connecting conductor v13a contacts the internal conductor layer 19a. The upper end (end in the positive direction of the Z-axis) of the third interlayer connecting conductor v13b contacts the mounting electrode E2. The lower end (end in the negative direction of the Z-axis) of the third interlayer connecting conductor v13b contacts the internal conductor layer 19b. The upper end (end in the positive direction of the Z-axis) of the third interlayer connecting conductor v13c contacts the conductor layer 18c. The lower end (the end in the negative direction of the Z axis) of the third interlayer connection conductor v13c is in contact with the internal conductor layer 19c.

[0054] The third interlayer-connecting conductors v13a to v13c have a shape in which the area of ​​the cross section perpendicular to the up-down direction decreases from top to bottom. Specifically, the third interlayer-connecting conductors v13a to v13c have a truncated cone shape. The area of ​​the upper ends of the third interlayer-connecting conductors v13a to v13c is smaller than the area of ​​the lower ends of the third interlayer-connecting conductors v13a to v13c.

[0055] The Young's modulus of the third interlayer connecting conductors v13a to v13c described above is higher than that of the fourth region A4, which will be described later. The Young's modulus of the third interlayer connecting conductors v13a to v13c is equal to that of the third region A3, which will be described later. The material of such third interlayer connecting conductors v13a to v13c is the same as that of the mounting electrodes E1 to E3. Therefore, the material of the third interlayer connecting conductors v13a to v13c is, for example, copper, aluminum, or silver.

[0056] The fourth interlayer connection conductor V4 penetrates the resin layer 14b in the vertical direction (Z-axis direction). The fourth interlayer connection conductor V4 overlaps with the mounting electrode E2 when viewed in the vertical direction (Z-axis direction). The upper end (the end in the positive direction of the Z-axis) of the fourth interlayer connection conductor V4 is in contact with the internal conductor layer 19b.

[0057] The fourth interlayer connection conductor V4 includes a third region A3 and a fourth region A4 aligned in the vertical direction (Z-axis direction). The fourth region A4 is located below the third region A3. The volume of the third region A3 is 30% or more of the volume of the fourth interlayer connection conductor V4. The Young's modulus of the fourth region A4 is lower than that of the third region A3. The material of the third region A3 is the same as the material of the mounting electrodes E1 to E3. Therefore, the material of the third region A3 and the material of the mounting electrodes E1 to E3 are, for example, copper, aluminum, or silver. The material of the fourth region A4 is an alloy primarily containing tin. The alloy primarily containing tin is, for example, an alloy of tin and copper or an alloy of tin and silver. The fourth region A4 is formed by sintering a conductive paste, which is a mixture of metal powder and resin. The other structural features of the circuit module 10c are the same as those of the circuit module 10, and therefore will not be described here. The circuit module 10c can achieve the effect (b).

[0058] The circuit module 10c can prevent damage to the connection between the third interlayer connection conductor v13a and the internal conductor layer 19a. More specifically, the surface of the connection member B2 is made of gold. Therefore, the connection member B2 is bonded to the mounting electrode E2 using ultrasonic bonding technology. To firmly bond the connection member B2 to the mounting electrode E2, the mounting electrode E2 only needs to be supported by the hard third interlayer connection conductor v13b. For example, the material of the third interlayer connection conductor v13b may be the same as the material of the mounting electrode E2. This allows ultrasonic vibrations to be efficiently transmitted to the connection member B2 and the mounting electrode E2. As a result, the connection member B2 is firmly bonded to the mounting electrode E2.

[0059] However, if the third interlayer connection conductor v13b is too hard, damage may occur at the connection between the third interlayer connection conductor v13b and the internal conductor layer 19b. More specifically, the upper end of the third interlayer connection conductor v13b contacts the mounting electrode E2. The lower end of the third interlayer connection conductor v13b contacts the internal conductor layer 19b. Therefore, the ultrasonic vibration is transmitted to the third interlayer connection conductor v13b and the internal conductor layer 19b via the mounting electrode E2. If the third interlayer connection conductor v13b is too hard, the ultrasonic vibration is likely to be applied to the joint between the third interlayer connection conductor v13b and the internal conductor layer 19b.

[0060] Therefore, the upper end of the fourth interlayer connection conductor V4 contacts the internal conductor layer 19b. The fourth interlayer connection conductor V4 includes a third region A3 and a fourth region A4 aligned in the vertical direction (Z-axis direction). The Young's modulus of the fourth region A4 is lower than that of the third region A3. As a result, the internal conductor layer 19b is supported by the fourth interlayer connection conductor V4, including the soft fourth region A4. Therefore, when ultrasonic vibrations are applied to the third interlayer connection conductor v13b and the internal conductor layer 19b, the fourth region A4 absorbs the ultrasonic vibrations. Force is less likely to be applied to the connection between the third interlayer connection conductor v13b and the internal conductor layer 19b. Therefore, the circuit module 10c can prevent damage to the connection between the third interlayer connection conductor v13b and the internal conductor layer 19b.

[0061] In the process of forming the fourth interlayer connection conductor V4, a through hole is formed in the resin layer 14b in the vertical direction (Z-axis direction). The through hole is plated to form the third region A3. After the third region A3 is formed, the through hole is filled with a conductive paste, which is then solidified by heating to form the fourth region A4.

[0062] Other Embodiments The multilayer substrate according to the present invention is not limited to the circuit modules 10, 10a to 10c, and can be modified within the scope of the invention. Furthermore, the structures of the circuit modules 10, 10a to 10c may be combined in any manner.

[0063] The item 100 is not limited to an electronic component. The item 100 may be a circuit board. In this case, the connection members B1 to B3 are mounting electrodes of the circuit board. Gold is present on the surfaces of the connection members B1 to B3.

[0064] The surface materials of the connection members B1 to B3 may be other than gold, such as aluminum or silver.

[0065] The material of the first region A1 may be different from the material of the mounting electrodes E1 to E3.

[0066] The multilayer substrate may further include a protective layer that covers the lower main surface of the laminate 12 .

[0067] The materials of the conductor layers 18a to 18c and 20a to 20c, the materials of the internal conductor layers 19a to 19f, the material of the first region A1, and the material of the third region A3 may be aluminum or silver.

[0068] The fourth area A4 may be located above the third area A3.

[0069] Note that the phrase "the first region A1 and the second region A2 are arranged in this order downward" includes cases where the first region A1 is located above the second region A2, as well as cases where at least a portion of the second region A2 is located below the first region A1. In this case, the first region A1 and the second region A2 may be in contact with the conductor layers 18a and 18b. However, the area where the first region A1 is in contact with the conductor layers 18a and 18b is equal to or larger than the area where the second region A2 is in contact with the conductor layers 18a and 18b.

[0070] The lower main surface of the conductor layer 18a has a uniform structure. A uniform structure means a planar shape or a shape with periodic irregularities. The boundary between the first region A1 and the conductor layer 18a is the lower main surface where the state of the lower main surface of the conductor layer 18a is uniform. In other words, due to the existence of irregularities on the lower main surface of the conductor layer 18a, protrusions protruding downward from the conductor layer 18a are part of the conductor layer 18a, and not part of the first region A1.

[0071] The present invention has the following structure:

[0072] (1) A circuit board and an article, wherein the circuit board comprises: a laminate having a structure in which a plurality of resin layers, each having a positive main surface located in the positive direction of the Z axis, are laminated in the Z axis direction; a mounting electrode located on the positive main surface of the resin layer located furthest in the positive direction of the Z axis among the plurality of resin layers; an internal conductor layer provided on the laminate and overlapping the mounting electrode as viewed in the Z axis direction; and a first interlayer connection conductor penetrating the resin layer in the Z axis direction, wherein an end of the first interlayer connection conductor in the positive direction of the Z axis contacts the mounting electrode and an end of the first interlayer connection conductor in the negative direction of the Z axis contacts the internal conductor layer; and the article comprises: a connecting member solid-state welded to the mounting electrode, wherein the first interlayer connection conductor includes a first region and a second region, and the first region and the second region are arranged in this order in the negative direction of the Z axis, The Young's modulus of the second region is lower than the Young's modulus of the first region.

[0073] (2) The circuit module according to (1), wherein the volume of the first region is 30% or more of the volume of the first interlayer connection conductor.

[0074] (3) The circuit module according to (1) or (2), wherein the material of the first region is the same as the material of the mounting electrode.

[0075] (4) The circuit module according to (3), wherein the material of the first region and the material of the mounting electrode are copper, aluminum, or silver.

[0076] (5) The circuit module according to any one of (1) to (4), wherein the material of the second region is an alloy containing tin as a main component.

[0077] (6) A circuit module described in any one of (1) to (5), wherein the circuit board further includes a second interlayer connection conductor located in the negative direction of the Z axis from the first interlayer connection conductor and penetrating the resin layer in the Z axis direction, and the Young's modulus of the second interlayer connection conductor is lower than the Young's modulus of the first region.

[0078] (7) The circuit module according to (6), wherein the second interlayer connection conductor is made of an alloy containing tin as a main component.

[0079] (8) The circuit module according to any one of (1) to (7), wherein the circuit board further includes a protective layer covering the front main surface of the resin layer that is located furthest in the positive direction of the Z axis among the plurality of resin layers.

[0080] (9) The circuit module according to any one of (1) to (8), wherein the material of the resin layer is a thermoplastic resin.

[0081] (10) The circuit module according to any one of (1) to (9), wherein the material of the surface of the connection member is gold.

[0082] (11) The circuit module according to any one of (1) to (10), wherein the Young's modulus of the lower half of the first interlayer connection conductor is different from the Young's modulus of the upper half of the first interlayer connection conductor.

[0083] (12) The circuit module according to any one of (1) to (11), wherein the first interlayer connection conductor has a truncated cone shape.

[0084] (13) A method for manufacturing a circuit module according to any one of (1) to (12), wherein in the step of forming the first interlayer connection conductor, a through hole penetrating the resin layer in the Z-axis direction is formed, the through hole is plated to form the first region, and after forming the first region, the through hole is filled with a conductive paste to form the second region, and the connection member is joined to the mounting electrode by ultrasonic bonding technology.

[0085] (14) A circuit board and an article, wherein the circuit board comprises: a laminate having a structure in which a plurality of resin layers, each having a front principal surface located in the positive direction of the Z axis, are laminated in the Z axis direction; a mounting electrode located on the front principal surface of the resin layer located furthest in the positive direction of the Z axis among the plurality of resin layers; an internal conductor layer provided on the laminate and overlapping the mounting electrode as viewed in the Z axis direction; a third interlayer connection conductor penetrating the resin layer in the Z axis direction, wherein an end of the third interlayer connection conductor in the positive direction of the Z axis contacts the mounting electrode and an end of the third interlayer connection conductor in the negative direction of the Z axis contacts the internal conductor layer; and a fourth interlayer connection conductor penetrating the resin layer in the Z axis direction and overlapping the mounting electrode as viewed in the Z axis direction, wherein the end of the fourth interlayer connection conductor in the positive direction of the Z axis contacts the internal conductor layer; and the article, wherein a connecting member that is solid-state welded to the mounting electrode, wherein the fourth interlayer connection conductor includes a third region and a fourth region that are aligned in the Z-axis direction, the material of the third interlayer connection conductor and the material of the third region are the same as the material of the mounting electrode, and the Young's modulus of the fourth region is lower than the Young's modulus of the third region.

[0086] (15) A method for manufacturing a circuit module according to (14), wherein in the step of forming the fourth interlayer connection conductor, a through hole penetrating the resin layer in the Z-axis direction is formed, and the third region is formed by plating the through hole, and after the third region is formed, the fourth region is formed by filling the through hole with a conductive paste, and in the step of joining the connection member to the mounting electrode, the connection member is joined to the mounting electrode by ultrasonic joining technology.

[0087] 10, 10a to 10c: Circuit module 11, 11a: Circuit board 12: Laminate 14a to 14d: Resin layer 16: Protective layer 18a to 18c, 20a to 20c: Conductor layer 19a to 19f: Internal conductor layer 100: Article 102: Article main body A1: First region A2: Second region A3: Third region A4: Fourth region B1 to B3: Connection member E1 to E3: Mounting electrodes V1a, V1b: First interlayer connection conductor V4: Fourth interlayer connection conductor v1, v3a to v3c: Interlayer connection conductor v13a to v13c: Third interlayer connection conductor v2a to v2f: Second interlayer connection conductor

Claims

1. A circuit board; The goods, Equipped with The circuit board includes: a laminate having a structure in which a plurality of resin layers, each having a positive principal surface located in the positive direction of the Z axis, are laminated in the Z axis direction; a mounting electrode located on the positive principal surface of a resin layer that is located furthest in the positive direction of the Z axis among the plurality of resin layers; an internal conductor layer provided on the laminate and overlapping the mounting electrode when viewed in the Z-axis direction; a first interlayer connection conductor penetrating the resin layer in the Z-axis direction, an end of the first interlayer connection conductor in the positive direction of the Z-axis being in contact with the mounting electrode and an end of the first interlayer connection conductor in the negative direction of the Z-axis being in contact with the internal conductor layer; Equipped with The article comprises: A connection member to be solid-phase-joined to the mounting electrode, We are equipped with the first interlayer connection conductor includes a first region and a second region; the first region and the second region are arranged in this order in the negative direction of the Z axis, the first region is in contact with the mounting electrode, The Young's modulus of the second region is lower than the Young's modulus of the first region. Circuit module.

2. a volume of the first region is 30% or more of a volume of the first interlayer connection conductor; The circuit module according to claim 1 .

3. The material of the first region is the same as the material of the mounting electrode. The circuit module according to claim 1 or 2.

4. The material of the first region and the material of the mounting electrode are copper, aluminum, or silver. The circuit module according to claim 3 .

5. The material of the second region is an alloy mainly composed of tin. The circuit module according to claim 1 or 2.

6. The circuit board includes: a second interlayer connection conductor located in a negative direction of the Z-axis from the first interlayer connection conductor and penetrating the resin layer in the Z-axis direction; In addition, The Young's modulus of the second interlayer connection conductor is lower than the Young's modulus of the first region. The circuit module according to claim 1 or 2.

7. the material of the second interlayer connection conductor is an alloy containing tin as a main component; The circuit module according to claim 6 .

8. The circuit board includes: A protective layer covering the positive main surface of the resin layer located most in the positive direction of the Z axis among the plurality of resin layers, In addition, The circuit module according to claim 1 or 2.

9. The material of the resin layer is a thermoplastic resin. The circuit module according to claim 1 or 2.

10. The material of the surface of the connection member is gold. The circuit module according to claim 1 or 2.

11. the Young's modulus of a lower half of the first interlayer connection conductor is different from the Young's modulus of an upper half of the first interlayer connection conductor; The circuit module according to claim 1 or 2.

12. the first interlayer connection conductor has a truncated cone shape; The circuit module according to claim 1 or 2.

13. 3. A method for manufacturing the circuit module according to claim 1, further comprising the steps of: In the step of forming the first interlayer connection conductor, a through hole penetrating the resin layer in the Z-axis direction is formed, and the first region is formed by plating the through hole. After the first region is formed, the through hole is filled with a conductive paste to form the second region. The connection member is joined to the mounting electrode by ultrasonic bonding. A method for manufacturing a circuit module.

14. A circuit board; The goods, Equipped with The circuit board includes: a laminate having a structure in which a plurality of resin layers, each having a positive principal surface located in the positive direction of the Z axis, are laminated in the Z axis direction; a mounting electrode located on the positive principal surface of a resin layer that is located furthest in the positive direction of the Z axis among the plurality of resin layers; an internal conductor layer provided on the laminate and overlapping the mounting electrode when viewed in the Z-axis direction; a third interlayer connection conductor penetrating the resin layer in the Z-axis direction, an end of the third interlayer connection conductor in the positive direction of the Z-axis being in contact with the mounting electrode and an end of the third interlayer connection conductor in the negative direction of the Z-axis being in contact with the internal conductor layer; a fourth interlayer connection conductor that penetrates the resin layer in the Z-axis direction and overlaps with the mounting electrode when viewed in the Z-axis direction, and an end of the fourth interlayer connection conductor in the positive direction of the Z-axis is in contact with the internal conductor layer; Equipped with The article comprises: A connection member to be solid-phase bonded to the mounting electrode, We are equipped with the fourth interlayer connection conductor includes a third region and a fourth region aligned in the Z-axis direction, the third region is in contact with the internal conductor layer, a material of the third interlayer connection conductor and a material of the third region are the same as a material of the mounting electrode, The Young's modulus of the fourth region is lower than the Young's modulus of the third region. Circuit module.

15. A method for manufacturing a circuit module according to claim 14, comprising the steps of: In the step of forming the fourth interlayer connection conductor, a through hole penetrating the resin layer in the Z-axis direction is formed, and the through hole is plated to form the third region. After the third region is formed, the through hole is filled with a conductive paste to form the fourth region. In the step of joining the connection member to the mounting electrode, the connection member is joined to the mounting electrode by ultrasonic bonding. A method for manufacturing a circuit module.