JP6287538B2 - Multilayer substrate and manufacturing method thereof - Google Patents

Description

  The present invention relates to a multilayer substrate and a manufacturing method thereof.

  In order to achieve high heat resistance, high reliability, and downsizing of an in-vehicle ECU (Electronic Control Unit), a component-embedded substrate using an LCP (Liquid Crystal Polymer) resin has become widespread. In-vehicle ECUs use lead parts such as vehicle connectors. In order to mount the lead component, a through hole is formed in the substrate.

  Patent Document 1 discloses a multilayer printed circuit board in which a plurality of resin films are superimposed. In the multilayer printed board of Patent Document 1, a conductive paste is formed on the conductor pattern around the through hole. A plurality of resin films are superposed by a heat fusion press.

JP 2009-130050 A

Problems that occur in the multilayer printed circuit board of Patent Document 1 will be described with reference to FIG.
FIG. 19 is a cross-sectional view showing a configuration around the through-hole 1 of the multilayer printed board. In FIG. 19, the conductors 112, 122, and 132 are provided on the resin films 110 to 130, respectively. The conductor 112 and the conductor 122 are connected by a conductive paste 122. The conductor 122 and the conductor 132 are connected by a conductive paste 133.

  Conductive pastes 132 and 133 are formed around the through-hole 1. Therefore, when the plurality of resin films 110 to 130 are overlapped, the conductive pastes 123 and 133 of each layer overlap. The portion where the conductive paste 123 and the conductive paste 133 overlap is thicker by the thickness T than the portion that does not overlap. Therefore, when a plurality of substrates are collectively heat fusion pressed, the press pressure is concentrated around the through-hole 1. Therefore, depending on the press pressure, the multilayer printed circuit board may be damaged, and productivity is lowered.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a highly productive multilayer substrate and a method for manufacturing the same.

  A multilayer substrate according to one embodiment of the present invention is a multilayer substrate including n (n is an integer of 3 or more) substrates, and conductive patterns are provided on both surfaces of each substrate, and the substrate is formed on the substrate. Inner wall conductors for connecting the conductive patterns on both sides of the substrate are provided on the inner walls of the through holes, and the through holes are connected to connect the conductive patterns provided facing two adjacent substrates. A conductive sintered body is provided between the two substrates in the periphery of the substrate, and the sintered body provided between the substrates is shifted from a sintered body provided between the other substrates in plan view. It is what has been.

In the multilayer substrate, the through holes provided in the n substrates are arranged so as to overlap each other in a plan view, so that a through through hole penetrating the multilayer substrate is provided. A bonded body is formed in a part of the through-through hole in the circumferential direction, and the sintered body provided between the substrates in the plan view is provided with the sintered body provided between the other substrates and the through-through hole. It may be displaced in the circumferential direction.
In the multilayer substrate, the sintered body is provided between (n-1) substrates provided in the multilayer substrate around the through-through hole, and the through-through hole is seen in a plan view. By providing the sintered body in a region divided by (n-1) in the circumferential direction, (n-1) pieces of the sintered body correspond to one circumference of the through-through hole. It may be.
In the multilayer substrate, the through-hole provided in the substrate may be arranged so as to be shifted from the through-hole provided in the other substrate in a plan view.
In the multilayer substrate, the through holes provided in the substrate may be arranged without overlapping with all other through holes in plan view.
In the multilayer substrate, the two adjacent substrates may be welded.

A manufacturing method of a multilayer substrate according to one embodiment of the present invention is a manufacturing method of a multilayer substrate including n (n is an integer of 3 or more) substrates, and includes a through hole, a conductive pattern provided on both surfaces, and A step of preparing n substrates each having an inner wall conductor provided on the inner wall of the through hole to connect the conductive patterns provided on both surfaces; and forming a conductive paste on the conductive pattern And the step of laminating the n number of substrates, and the conductive paste is sintered in a state where the n number of the laminated substrates are pressed to be opposed to the two adjacent substrates. Forming a sintered body for connecting the conductive patterns, and in a plan view, the sintered body provided between the substrates is displaced from a sintered body provided between other substrates. Are arranged.
In the above manufacturing method, the through holes provided in the n substrates are arranged so as to overlap each other in plan view, thereby providing a through through hole penetrating the multilayer substrate, and the firing between the substrates is performed. A bonded body is formed in a part of the through-through hole in the circumferential direction, and the sintered body provided between the substrates in the plan view is provided with the sintered body provided between the other substrates and the through-through hole. It may be displaced in the circumferential direction.

In the above manufacturing method, the sintered body is provided between the (n-1) substrates provided in the multilayer substrate around the through-through hole, and the through-through hole is seen in a plan view. By providing the sintered body in a region divided by (n-1) in the circumferential direction, (n-1) pieces of the sintered body correspond to one circumference of the through-through hole. It may be.
In the above manufacturing method, the through hole provided in the substrate may be shifted from the through hole provided in another substrate in a plan view.
In the above manufacturing method, the through holes provided in the substrate may be arranged without overlapping with all other through holes in a plan view.
In the above manufacturing method, when the conductive paste is sintered, two adjacent substrates may be welded.

  According to the present invention, it is possible to provide a multilayer substrate with high productivity and a method for manufacturing the same.

It is a figure which shows sectional drawing which shows the structure of the multilayer substrate which concerns on this embodiment. It is sectional drawing for demonstrating the structure of each board | substrate of the multilayer substrate which concerns on this embodiment. It is a top view which shows the structure around a through-hole. It is a top view which shows the surrounding structure of a 2nd lure hole. It is a top view which shows the structure around a 3rd through hole. It is a top view which shows the structure around a 4th through hole. It is a top view which shows the structure around a 5th through hole. It is a flowchart which shows the manufacturing method of the multilayer substrate which concerns on this embodiment. It is a manufacturing process sectional view of a multilayer substrate concerning this embodiment. It is a manufacturing process sectional view of a multilayer substrate concerning this embodiment. It is a manufacturing process sectional view of a multilayer substrate concerning this embodiment. It is a manufacturing process sectional view of a multilayer substrate concerning this embodiment. In the manufacturing process of the multilayer substrate concerning this embodiment, it is a sectional view expanding and showing the circumference of a through hole. It is a manufacturing process sectional view of a multilayer substrate concerning this embodiment. It is a manufacturing process sectional view of a multilayer substrate concerning this embodiment. In the manufacturing method of the multilayer substrate concerning this Embodiment 2, it is a sectional view showing the composition of the lamination structure. It is sectional drawing which shows the structure of the multilayer substrate concerning this Embodiment 2. FIG. 6 is a plan view showing a configuration around a second through hole in a multilayer substrate according to a second embodiment. It is sectional drawing for demonstrating the reason that pressure concentration generate | occur | produces around a through hole.

  Hereinafter, embodiments of a processing method and a processing apparatus according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. In addition, for clarity of explanation, the following description and drawings are simplified as appropriate.

Embodiment 1 FIG.
The multilayer substrate according to this embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view showing the configuration of the multilayer substrate 100. In the following drawings, an explanation will be given using an orthogonal coordinate system where the thickness direction of the multilayer substrate 100 is the Z direction and the directions orthogonal to the Z direction are the X direction and the Y direction as appropriate. The X direction and the Y direction are orthogonal to each other within the main surface of the multilayer substrate 100. Further, the + Z side is the upper side of the multilayer substrate 100, and the −Z side is the lower side of the multilayer substrate 100.

  The multilayer substrate 100 includes a first substrate 10, a second substrate 20, a third substrate 30, a fourth substrate 40, and a fifth substrate 50. The first substrate 10, the second substrate 20, the third substrate 30, the fourth substrate 40, and the fifth substrate 50 are stacked in order from the top. Here, the laminated substrate 100 has five substrates, but the number of substrates may be three or more.

  For example, each of the first substrate 10 to the fifth substrate 50 is an LCP substrate, and the basic configuration is the same. The first substrate 10 is a plate-like member made of an insulating base material such as a liquid crystal polymer. Furthermore, the conductor 12 is formed on both surfaces of the first substrate 10. The second substrate 20 to the fifth substrate 50 also have the same configuration as the first substrate 10. Conductors 22 are formed on both surfaces of the second substrate 20. Conductors 32 are formed on both surfaces of the third substrate 30. Conductors 42 are formed on both surfaces of the fourth substrate 40. Conductors 52 are formed on both surfaces of the fifth substrate 50. The conductors 22 to 52 are wirings provided on the first substrate 10 to the fifth substrate 50, respectively.

  Further, a conductive sintered body 23 is provided between the first substrate 10 and the second substrate 20. The sintered body 23 electrically connects the conductor 12 and the conductor 22. Similarly, a sintered body 33 that electrically connects the conductor 22 and the conductor 32 is provided between the second substrate 20 and the third substrate 30. A sintered body 43 that electrically connects the conductor 32 and the conductor 42 is provided between the third substrate 30 and the fourth substrate 40. A sintered body 53 that electrically connects the conductor 42 and the conductor 52 is provided between the fourth substrate 40 and the fifth substrate 50. The sintered bodies 23 to 53 have a thickness of 100 to 200 μm, for example.

  The multilayer substrate 100 is provided with through through holes 1 penetrating the first substrate 10 to the fifth substrate 50. A lead or the like is inserted into the space of the through through hole 1. As a result, lead components (not shown) are mounted on the multilayer substrate 100. By providing the through through hole 1, the conductor 12 of the first substrate 10 and the conductor 52 of the fifth substrate 50 are electrically connected.

  Further, the third substrate 30 and the fourth substrate 40 are provided with a space 61 for arranging the electronic component 60. The electronic component 60 is, for example, a semiconductor device such as an IC, a resistor, a capacitor, or the like. The electronic component 60 is mounted on the fifth substrate 50. The electronic component 60 is connected to the conductor 52. Thus, the multilayer substrate 100 is a component built-in substrate in which the electronic component 60 is built.

  Next, the through-through hole 1 and the surrounding configuration will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the multilayer substrate 100 in a state where the substrates are separated, in order to explain the configuration of each substrate constituting the multilayer substrate 100.

  The multilayer substrate 100 includes the first substrate 10 to the fifth substrate 50 as described above. Here, an interlayer portion 29 is defined between the first substrate 10 and the second substrate 20. Similarly, an interlayer portion 39 is provided between the second substrate 20 and the third substrate 30, and an interlayer portion 49 is provided between the third substrate 30 and the fourth substrate 40, and the fourth substrate 40 and the fifth substrate 50 are The space is referred to as an interlayer portion 59.

  As described above, the first substrate 10 to the fifth substrate 50 include the conductors 12 to 52, respectively. The first substrate 10 includes a first through hole 11 and a conductor 12. The conductor 12 includes a conductive pattern 12a, a conductive pattern 12b, and an inner wall conductor 12c. The conductive pattern 12a is formed on the upper surface of the first substrate 10, that is, on the + Z side surface. The conductive pattern 12b is formed on the lower side of the first substrate 10, that is, on the −Z side surface.

  The first through hole 11 passes through the first substrate 10. An inner wall conductor 12 c is formed on the inner wall of the first through hole 11. Since the inner wall conductor 12c is formed over the entire inner wall of the first through hole 11, the first through hole 11 is illustrated as being filled with the inner wall conductor 12c in FIG. The conductive pattern 12 a and the inner wall conductor 12 c are formed around the first through hole 11.

  The conductive pattern 12 a is electrically connected to the conductive pattern 12 b via the inner wall conductor 12 c in the first through hole 11. Therefore, the conductive patterns 12a and 12b provided on both surfaces of the first substrate 10 are electrically connected via the inner wall conductor 12c. In FIG. 2, the conductive pattern 12 a and the conductive pattern 12 b are formed in a recess provided in the first substrate 10. That is, by processing the first substrate 10, concave portions for providing the conductive pattern 12 a and the conductive pattern 12 b are formed.

  The second substrate 20 to the fifth substrate 50 have the same configuration as the first substrate 10. Therefore, the conductive pattern 22a and the conductive pattern 22b provided on both surfaces of the second substrate 20 are connected via the inner wall conductor 22c. The conductive pattern 32a and the conductive pattern 32b provided on both surfaces of the third substrate 30 are connected via an inner wall conductor 32c. The conductive pattern 42a and the conductive pattern 42b provided on both surfaces of the fourth substrate 40 are connected via an inner wall conductor 42c. The conductive pattern 52a and the conductive pattern 52b provided on both surfaces of the fifth substrate 50 are connected via an inner wall conductor 52c. As described above, each of the first substrate 10 to the fifth substrate 50 has conductive patterns provided on both surfaces.

  The inner wall conductors 12c to 52c are formed on the inner walls of the first through hole 11 to the fifth through hole 51, respectively. The first through hole 11 to the fifth through hole 51 are arranged so as to overlap each other. In the through hole 1, the first through hole 11, the second through hole 21, the third through hole 31, the fourth through hole 41, and the fifth through hole 51 are substantially the same size.

  In the XY plan view, the first through hole 11 to the fifth through hole 51 are formed at the same position, whereby the through through hole 1 penetrating the multilayer substrate 100 is formed. The through through hole 1 includes a first through hole 11, a second through hole 21, a third through hole 31, a fourth through hole 41, and a fifth through hole 51.

  In the interlayer portion 29, a conductive sintered body 23 is provided. The sintered body 23 is disposed between the conductive pattern 12b and the conductive pattern 22a. That is, in the XY plan view, the sintered body 23 is provided at a position overlapping the conductive pattern 12b and the conductive pattern 22a, and is in contact with the conductive pattern 12b and the conductive pattern 22a. Thereby, the conductive pattern 12b and the conductive pattern 22a are connected.

  The sintered bodies 23 to 53 are, for example, sintered bodies obtained by sintering a copper paste and have conductivity. The sintered bodies 33 to 53 are also arranged in the same manner as the sintered body 23. The sintered body 33 of the interlayer part 39 is disposed between the conductive pattern 22b and the conductive pattern 32a. Therefore, the conductive pattern 22 b and the conductive pattern 32 a are connected via the sintered body 33. Similarly, the sintered body 43 of the interlayer part 49 is disposed between the conductive pattern 32b and the conductive pattern 42a. The conductive pattern 32 b and the conductive pattern 42 a are connected via the sintered body 43. The sintered body 53 of the interlayer part 59 is disposed between the conductive pattern 42b and the conductive pattern 52a. The conductive pattern 42 b and the conductive pattern 52 a are connected via the sintered body 53. The conductive pattern of each layer is connected via a sintered body.

  In this way, the uppermost conductive pattern 12 a and the lowermost conductive pattern 52 b are electrically connected via the sintered bodies 23 to 53. That is, by providing the through-hole 1 penetrating from the upper surface to the lower surface of the multilayer substrate 100, the conductive pattern 12a provided on the uppermost surface of the multilayer substrate 100 and the conductive pattern 52b provided on the lowermost surface are electrically connected. Connecting. In FIG. 2, ten layers of conductive patterns are electrically connected.

  The third substrate 30 and the fourth substrate 40 are formed with component through holes 38 and 48 for placing the electronic component 60, respectively. A space 61 for forming the electronic component 60 shown in FIG. 1 is formed by the component through hole 38 and the component through hole 48.

  Here, the arrangement of the sintered bodies 23 to 53 provided around the through-hole 1 will be described with reference to FIGS. FIG. 3 is an XY plan view schematically showing the arrangement of the sintered bodies 23 to 53 provided around the through-hole 1. FIG. 4 is an XY plan view schematically showing a configuration around the second through hole 21 of the second substrate 20. FIG. 5 is an XY plan view schematically showing a configuration around the third through hole 31 of the third substrate 30. FIG. 6 is an XY plan view schematically showing a configuration around the fourth through hole 41 of the fourth substrate 40. FIG. 7 is an XY plan view schematically showing a configuration around the fifth through hole 51 of the fifth substrate 50.

  As shown in FIG. 3, the penetrating through hole 1 is formed in a circular shape. A sintered body 23, a sintered body 33, a sintered body 43, and a sintered body 53 are provided around the through through hole 1. The sintered body 23, the sintered body 33, the sintered body 43, and the sintered body 53 are each disposed in a part of the periphery of the through-through hole 1. In the XY plan view, the sintered body 23, the sintered body 33, the sintered body 43, and the sintered body 53 are arranged so as not to overlap each other. Specifically, the sintered body 23, the sintered body 33, the sintered body 43, and the sintered body 53 are arranged in a fan-shaped region obtained by dividing the peripheral portion of the through through hole 1 in the circumferential direction.

  For example, the sintered body 23 is disposed on the upper right side of the through through hole 1, and the sintered body 33 is disposed on the lower left side of the through through hole 1. The sintered body 43 is disposed on the lower right side of the through through hole 1, and the sintered body 53 is disposed on the upper left side of the through through hole 1. Therefore, in the XY plan view, the sintered body 23, the sintered body 43, the sintered body 33, and the sintered body 53 are arranged in the clockwise direction in the circumferential direction around the center of the through-hole 1.

  FIG. 4 shows a configuration around the second through hole 21. In the XY plan view, the second through hole 21 is provided in a circular shape having the same size as the through through hole 1. The conductive pattern 22 a is formed around the second through hole 21. The conductive pattern 22 a is disposed on the entire circumferential direction of the second through hole 21. The conductive pattern 22 a around the second through hole 21 serves as an electrode pad for connection with the sintered body 23.

  The sintered body 23 is formed so as to overlap with a part of the conductive pattern 22a. In the XY plan view, the conductive pattern 22 a is formed in an annular shape so as to surround the second through hole 21. A sintered body 23 is disposed on a part of the conductive pattern 22a. Specifically, the sintered body 23 is arranged by 90 ° in the circumferential direction. Considering an XY orthogonal coordinate system with the center of the through-hole 1 as the origin, the sintered body 23 is arranged in the first quadrant. The sintered body 23 is formed only in a part of the periphery of the second through hole 21.

  FIG. 5 shows a configuration around the third through hole 31. In the XY plan view, the third through hole 31 is provided in a circular shape having the same size as the through through hole 1. The conductive pattern 32 a is formed around the third through hole 31. The conductive pattern 32 a is disposed on the entire circumferential direction of the third through hole 31. The conductive pattern 32a around the third through hole 31 serves as an electrode pad for connection to the sintered body 33.

  The sintered body 33 is formed so as to overlap with a part of the conductive pattern 32a. In the XY plan view, the conductive pattern 32 a is formed in an annular shape so as to surround the third through hole 31. A sintered body 33 is disposed on a part of the conductive pattern 32a. Specifically, the sintered body 33 is arranged by 90 ° in the circumferential direction. Considering an XY orthogonal coordinate system with the center of the through-hole 1 as the origin, the sintered body 33 is arranged in the third quadrant. The sintered body 33 is formed only in a part of the periphery of the third through hole 31.

  Therefore, as shown in FIG. 3, the sintered body 23 and the sintered body 33 are arranged so as to face each other through the through-through hole 1. The sintered body 23 and the sintered body 33 have substantially the same area and substantially the same shape. Therefore, the sintered body 23 and the sintered body 33 are arranged rotationally symmetrically with respect to the center of the through through hole 1.

  FIG. 6 shows a configuration around the fourth through hole 41. In the XY plan view, the fourth through hole 41 is provided in a circular shape having the same size as the through through hole 1. The conductive pattern 42 a is formed around the fourth through hole 41. The conductive pattern 42 a is disposed on the entire circumferential direction of the fourth through hole 41. The conductive pattern 42 a around the fourth through hole 41 serves as an electrode pad for connection with the sintered body 43.

  The sintered body 43 overlaps with a part of the conductive pattern 42a. In the XY plan view, the conductive pattern 42 a is formed in an annular shape so as to surround the fourth through hole 41. And the sintered compact 43 is arrange | positioned on a part of conductive pattern 42a. Specifically, the sintered body 43 is arranged by 90 ° in the circumferential direction. Considering an XY orthogonal coordinate system with the center of the through-hole 1 as the origin, the sintered body 43 is arranged in the fourth quadrant. The sintered body 43 is formed only in a part of the periphery of the fourth through hole 41.

  FIG. 7 shows a configuration around the fifth through hole 51. In the XY plan view, the fifth through hole 51 is provided in a circular shape having the same size as the through through hole 1. The conductive pattern 52 a is formed around the fifth through hole 51. The conductive pattern 52 a is disposed on the entire circumferential direction of the fifth through hole 51. The conductive pattern 52 a around the fifth through hole 51 serves as an electrode pad for connecting to the sintered body 53.

  The sintered body 53 is formed so as to overlap with a part of the conductive pattern 52a. In the XY plan view, the conductive pattern 52 a is formed in an annular shape so as to surround the fifth through hole 51. A sintered body 53 is disposed on a part of the conductive pattern 52a. Specifically, the sintered body 53 is arranged by 90 ° in the circumferential direction. Considering an XY orthogonal coordinate system with the center of the through-hole 1 as the origin, the sintered body 53 is arranged in the second quadrant. The sintered body 53 is formed only in a part of the periphery of the fifth through hole 51.

  Therefore, as shown in FIG. 3, the sintered body 43 and the sintered body 53 are arranged so as to face each other through the through-through hole 1. The sintered body 43 and the sintered body 43 have substantially the same area and substantially the same shape. Therefore, the sintered body 43 and the sintered body 53 are arranged rotationally symmetrically with respect to the center of the through through hole 1.

  In the XY plan view, the sintered body 23, the sintered body 33, the sintered body 43, and the sintered body 53 have the same size and the same shape, and have different directions by 90 °. The sintered body 23, the sintered body 33, the sintered body 43, and the sintered body 53 each have a size corresponding to 90 ° in the circumferential direction. In the circumferential direction, the sintered body 23, the sintered body 33, the sintered body 43, and the sintered body 53 are arranged at a 90 ° pitch. Therefore, as shown in FIG. 3, in the XY plane, the sintered body 23, the sintered body 33, the sintered body 43, and the sintered body 53 are arranged at shifted positions so as not to overlap each other.

  Sintered bodies 23 to 53 are formed in a region obtained by radially dividing the periphery of the through through hole 1 into four. In a plan view, when the sintered body 23, the sintered body 33, the sintered body 43, and the sintered body 53 are synthesized, an annular shape surrounding the through-through hole 1 is obtained as shown in FIG. The region where the four sintered bodies 23 to 53 are provided makes a round around the through-hole 1. That is, the four sintered bodies 23 to 53 correspond to 360 ° in the circumferential direction. A sintered body is provided in a region obtained by dividing the periphery of the through-through hole 1 in the circumferential direction, that is, radially. By doing so, the four sintered bodies 23 to 53 correspond to one circumference of the through-hole 1.

  The positions of the sintered body 23 to the sintered body 53 are changed for each layer. That is, the sintered bodies 23 to 53 are arranged while being shifted in the circumferential direction. With such a configuration, a local thickness change can be reduced. In the press welding process for manufacturing the multilayer substrate 100, substrate damage due to concentration of the press pressure can be prevented. Therefore, productivity can be improved.

  Next, the manufacturing process of the multilayer substrate 100 will be described with reference to FIG. FIG. 8 is a flowchart showing the manufacturing process of the multilayer substrate. In the description of FIG. 8, the manufacturing process cross-sectional views of FIGS.

  First, as shown in FIG. 9, a base material 15 to be the first substrate 10 is introduced (S11). The base material 15 is an insulating substrate having a flat upper surface and lower surface. As described above, the base material 15 is a thermoplastic substrate such as an LCP substrate. The base material 15 is formed with a thickness of 100 to 200 μm, for example. Further, as the base material 15, a glass epoxy resin or other thermoplastic resin may be used. In addition, when using a glass epoxy resin as the base material 15, you may make it provide an adhesive sheet between board | substrates. When glass epoxy resin is used as the base material 15, the base material 15 has a thickness of about 0.4 mm to 1 mm. By using a flexible material as the base material 15, the first substrate 10 can be a flexible substrate.

  Next, as shown in FIG. 10, the base material 15 is processed and subjected to a hydrophilic treatment (S12). First, a through hole penetrating the base material 15 is formed, and the first through hole 11 and the through hole 18 are formed. In addition, a recess 16 is formed in the base material 15. That is, the recess 16 is formed by drilling the base material 15 halfway in the thickness direction. The recess 16 is formed around the first through hole 11 and the through hole 17 in order to form the conductor 12 in a later process. Further, the recess 16 is formed at a location where a wiring pattern is formed by the conductor 12. The recess 16 around the first through hole 11 is formed in an annular shape so as to surround the first through hole 11 in plan view. The recesses 16 are provided on both surfaces of the base material 15. The recess 16 is formed with a depth of several tens of μm, for example.

  Next, a hydrophilic treatment is performed on the surface of the substrate 15. A place where the conductor 12 is formed in a later step, for example, the recess 16, the inner wall of the first through hole 11, and the inner wall of the through hole 18 is subjected to a hydrophilic treatment. Here, the recess 16, the inner wall of the first through hole 11, and the inner wall of the through hole 18 are irradiated with an excimer laser or the like to perform a hydrophilic treatment. Of course, the hydrophilization treatment may be performed by a treatment other than the excimer laser irradiation.

  Then, a circuit pattern using copper ink is printed to form the conductor 12 (S13). Therefore, first, the base material 15 is set on the stage 80 as shown in FIG. The surface of the stage 80 has hydrophobicity. Then, a circuit pattern is printed on the base material 15 placed on the stage 80 using copper ink. For example, as shown in FIG. 12, the copper ink 82 is ejected from the nozzle 81 to the recess 16. Thereby, the copper ink 82 is applied to the portion of the base material 15 where the conductor 12 of the base material 15 is formed.

  FIG. 13 is an enlarged view of the dotted line circle portion of FIG. 12, that is, the peripheral portion of the first through hole 11. The surface of the base material 15 is a hydrophilic surface with respect to the copper ink 82 by the hydrophilization treatment. On the other hand, the surface of the stage 80 is a hydrophobic surface with respect to the copper ink 82. For this reason, the base material 15 has higher affinity for the copper ink 82 than the stage 80.

  Therefore, the copper ink 82 spreads wet to the concave portion 16 between the base material 15 and the stage 80 by capillary action. As a result, the copper ink is applied to the recess 16 provided on the lower surface of the substrate 15. That is, the copper ink 82 discharged on the upper surface of the base material 15 spreads to the lower surface of the base material 15 along the inner wall 11 b of the first through hole 11. As a result, the copper ink 82 is applied to both surfaces of the base material 15 and the inner wall 11 b of the first through hole 11.

  As described above, after the hydrophilic treatment, the copper ink 82 is applied to the upper surface of the base material 15. By carrying out like this, the conductor 22 can be formed in the both surfaces of a base material, and the inner wall of a through hole, without inverting the base material 15. FIG. Therefore, a printing process can be simplified and productivity can be improved.

  When the printing of the copper ink 82 is completed, the printed copper ink 82 is heated and cured (S14). Thereby, the copper ink 82 is thermally cured, and as shown in FIG. 14, the conductive pattern 22a, the conductive pattern 22b, and the inner wall conductor 22c are formed. That is, the first substrate 10 having the first through hole 11 and the conductor 12 is completed.

  By producing the second substrate 20 to the fifth substrate 50 by the same process as described above, the substrate of each layer can be prepared (S15). That is, a plurality of base materials are prepared, and steps S12 to S14 are performed for each. By doing so, the second substrate 20 to the fifth substrate 50 are produced. In addition, about the 5th board | substrate 50, after carrying out circuit printing with the copper ink 82, the electronic component 60 is mounted. Then, after mounting the electronic component 60, the copper ink 82 is heated and cured.

  The formation of the conductors 12 to 52 is not limited to the application of the copper ink 82. For example, it can be applied using conductive ink or paste. Alternatively, the conductors 12 to 52 may be formed by plating, vapor deposition, sputtering, or the like. As described above, any method may be used as long as the wiring pattern can be provided on the substrate surface.

  After preparing the first substrate 10 to the fifth substrate 50, a copper paste for interlayer connection is applied (S16). Here, as shown in FIG. 15, the copper paste 84 is applied to the upper surfaces of the second substrate 20, the third substrate 30, the fourth substrate 40, and the fifth substrate 50. The copper paste 84 is a sintered material, and becomes sintered bodies 23 to 53 through a heat curing step (S18) described later. Of course, a conductive paste other than a copper paste may be used.

  The copper paste 84 around the through-hole 1 is arranged so as not to overlap the copper paste 84 between other substrates. That is, as shown in FIG. 3, the copper paste 84 of each layer is applied to a 90 ° fan-shaped region in the circumferential direction of the through-hole 1 so that the sintered bodies 23 to 53 do not overlap. Accordingly, the four copper pastes 84 around the through-hole 1 correspond to one circumference (360 °) of the through-through hole 1 in the XY plane.

  Copper paste 84 is formed on conductive pattern 22a, conductive pattern 32a, conductive pattern 42a, and conductive pattern 52a. As described above, the copper paste 84 is applied on the conductive patterns 22a to 52a around the second through hole 21 to the fifth through hole 51, respectively. Further, the copper paste 84 is also applied to the through holes 27 other than the through hole 1, the through holes 37, and the conductive patterns 22 a to 42 a provided around the through holes 47.

  The copper paste 84 around the through-hole 1 is displaced so that the sintered bodies 23 to 53 have the configuration shown in FIG. That is, the interlayer copper paste 84 does not overlap in the XY plan view.

  The copper paste 84 is applied on the conductive patterns 22a to 42a so as to protrude from the surface of each substrate. In other words, the copper paste 84 is applied in an amount that protrudes from the recess provided in each base material. For example, the copper paste 84 on the conductive pattern 22a is formed so as to protrude to the + Z side from the recess 26. The copper paste 84 on the conductive pattern 22a protrudes toward the first substrate 10 from the surface of the base material 25. Similarly, the copper paste 84 on the conductive pattern 32 a protrudes to the second substrate 20 side from the surface of the base material 35. The copper paste 84 on the conductive pattern 42 a protrudes toward the third substrate 30 side from the surface of the base material 45. The copper paste 84 on the conductive pattern 52 a protrudes toward the fourth substrate 40 side from the surface of the base material 55.

  Then, the first substrate 10 to the fifth substrate 50 are stacked (S17). Thereby, as shown in FIG. 15, the laminated structure 101 in which the first substrate 10 to the fifth substrate 50 are laminated is formed. In the laminated structure 101, the first through hole 11 to the fifth through hole 51 overlap to form the through through hole 1.

  Next, the stacked first substrate 10 to fifth substrate 50 are press welded to heat cure the copper paste 84 (S18). For example, in the press welding step, the copper paste 84 is temporarily cured by heating at 70 ° C. to 80 ° C. for 15 minutes. After temporary curing, the laminated structure 101 is heated to about 180 ° C. to 300 ° C. in a state where the laminated first substrate 10 to fifth substrate 50 are pressed. As a result, the copper paste 84 is sintered to form the sintered bodies 23 to 53 as shown in FIGS. That is, the sintered bodies 23 to 53 fix the first substrate 10 to the fifth substrate 50.

  A sintered body in which the copper paste 84 is sintered is also formed in the through holes 27, 37, 47. For example, the copper paste 84 around the through hole 27 is disposed in the through hole 27 by a press pressure. Furthermore, in this heat curing step, the liquid crystal polymer as the base material 15 is melted, and the first substrate 10 to the fifth substrate 50 are welded. That is, the resin material of the base material 15 is welded, and the first substrate 10 to the fifth substrate 50 are fixed.

  In addition, what is necessary is just to determine the heating temperature in S18 with the welding temperature of the base materials 15-55. For example, when the first substrate 10 to the fifth substrate 50 are LCP substrates, they can be heated at 300 ° C. When the first substrate 10 to the fifth substrate 50 are glass epoxy resins, they can be heated at 180 ° C.

  Thus, a heating process can be reduced by performing press welding of the 1st substrate 10-the 5th substrate 50, and heat joining of copper paste 84 collectively. Thereby, the damage by a heat history can be reduced.

  Moreover, the position where the copper paste 84 is shifted for each layer is arranged. That is, the sintered bodies 23 to 53 do not overlap with the sintered bodies 23 to 53 of other layers. Therefore, the local thickness change of the laminated structure 101 can be reduced, and the concentration of the press pressure can be reduced. That is, since the press pressure applied to the periphery of the through through hole 1 can be reduced, the substrate can be prevented from being damaged. Therefore, productivity can be improved.

  Note that the copper paste 84 may be deformed by the pressing pressure. For example, the copper paste 84 at the time of application of S16 may spread due to the press pressure. In this case, the spread of the copper paste 84 can be reduced by temporarily curing the copper paste 84 before press-bonding. Thereby, it becomes easy to make the sintered compacts 23-53 into an appropriate shape. Further, due to the spreading of the copper paste 84, a part of the copper paste 84 may overlap with the copper paste 84 of another layer. Therefore, a part of the sintered body may overlap with the sintered body of the other layer.

  Next, the circuit pattern of the outermost layer is printed with ink (S19), and ink heating is performed (S20). That is, the copper ink is printed on at least one of the upper surface of the first substrate 10 and the lower surface of the fifth substrate 50. Here, the copper ink 82 can be printed by the nozzle 81 used in step S13. Then, by heating the copper ink 82, the conductive patterns 12a and 52b to be the outermost circuit patterns can be formed. Of course, the circuit pattern may be formed by a method different from S13. If all the outermost circuit patterns are formed in S13, steps S19 and S20 can be omitted. By doing so, the number of heating steps can be reduced.

  In the present embodiment, through holes are drilled, copper ink 82 is applied, and copper paste 84 is applied before the substrate is welded. Therefore, a manufacturing process can be shortened and productivity can be improved. Furthermore, since the through holes are formed in each substrate before the plurality of substrates are stacked, it is possible to prevent the LCP substrate from melting and covering the conductors 12 to 52 during press welding. Therefore, the interlayer connection by the through hole can be reliably performed, and the generation of defective products can be prevented. Thereby, productivity can be improved.

  A plurality of substrates are press welded together, and press welding and sintering are performed in the same heating process. Thereby, since the heating process after mounting an electronic component can be reduced, the influence by heat can be reduced.

  In this Embodiment, each board | substrate is joined by welding of the sintered compacts 23-53 and a board | substrate. Therefore, since a plurality of substrates can be securely fixed, connection reliability can be increased. The multilayer substrate 100 according to the present embodiment is suitable for an in-vehicle ECU because of high connection reliability. As described above, since the fixing can be ensured, the connection can be maintained even when the substrate is thermally expanded due to a temperature change. Therefore, the heat resistance and reliability of the multilayer substrate 100 can be improved.

  In the above description, the multilayer substrate 100 including five substrates has been described. However, the number of substrates may be three or more. In the case of three substrates, since the number of interlayer portions corresponding to the substrates is two, one sintered body corresponds to 180 ° around the through-hole 1. In the case of four substrates, since the number of interlayer portions is two, one sintered body corresponds to 120 ° around the through-through hole 1.

  It is assumed that the multilayer substrate 100 is composed of n (n is an integer of 3 or more) substrates. In this case, it is preferable to form one sintered body in a fan-shaped region of 360 ° / (n−1). That is, the outer periphery of the through-hole 1 is radially divided into (n−1) equal parts, and the sintered body of each layer is disposed. By making the areas where the respective sintered bodies are provided substantially the same, connection reliability by the sintered bodies can be improved.

  Of course, the size of the sintered body of each layer may be different. A sintered body is provided between the (n−1) substrates provided in the multilayer substrate 100 around the through-hole 1. Then, in the XY plan view, a sintered body is provided in a region obtained by dividing the periphery of the through-through hole 1 in the circumferential direction by (n−1), so that (n−1) sintered bodies are formed through the through-hole. This corresponds to one outer circumference of the. In other words, the sintered bodies are respectively arranged in the areas where the periphery of the through-hole 1 is radially divided. Thereby, a sintered compact can be formed over the circumference | surroundings of the outer periphery of the through through-hole 1, ie, the area | region corresponding to 360 degrees. Therefore, concentration of the press pressure can be prevented and productivity can be improved.

  In addition, the sintered bodies provided between the substrates do not have to be evenly disposed as long as they are displaced in the circumferential direction. For example, when five substrates 10 to 50 are provided so that there are four interlayer portions, the sintered bodies 23 and 33 are formed in a range of 80 °, and the sintered bodies 43 and 53 are 90 °. It may be formed in the range. As described above, the fan-shaped region forming the sintered body may have a different size for each interlayer portion. Or you may provide a clearance gap between the fan-shaped area | regions which form a sintered compact. For example, when five substrates 10 to 50 are provided so that there are four interlayer portions, the sintered bodies 23 to 53 may be formed in a range of 80 °. In this case, a 10 ° gap is generated between the sintered bodies in the XY plan view. A sintered body between the substrates is formed in a part of the through-through hole 1 in the circumferential direction, and the sintered body provided between the substrates is formed between the other substrates and the through-through in the XY plan view. What is necessary is just to be arrange | positioned and shifted | deviated to the circumferential direction of the hole 1. FIG.

Embodiment 2. FIG.
A configuration and manufacturing method of the multilayer substrate 100 according to the present embodiment will be described with reference to FIGS. 16 and 17 are cross-sectional views of the manufacturing process of the multilayer substrate 100. FIG. In the present embodiment, the arrangement of a plurality of through holes is different from that in the first embodiment. Specifically, the through holes of each layer are arranged so as not to overlap with the through holes of different layers. Since the configuration and manufacturing method of the multilayer substrate 100 according to the present embodiment are basically the same as those of the first embodiment, description thereof is omitted.

  In the present embodiment, as shown in FIGS. 16 and 17, the laminated structure 101 includes a first substrate 10, a second substrate 20, and a third substrate 30. That is, as shown in FIG. 17, the multilayer substrate 100 is composed of three substrates. The copper paste 84 formed in the interlayer part 29 becomes a sintered body 23 through a heating process, and connects the conductor 12 and the conductor 22. Similarly, the copper paste 84 formed in the interlayer part 39 becomes a sintered body 33 through a heating process, and connects the conductor 22 and the conductor 32.

  The first through hole 11, the second through hole 21, and the third through hole 31 are formed at different positions. That is, in the XY plan view, the first through hole 11, the second through hole 21, and the third through hole 31 are arranged so as not to overlap each other.

  When the laminated structure 101 shown in FIG. 17 is press-welded, the sintered bodies 23 and 33 are obtained by sintering the copper paste 84 as shown in FIG. Therefore, the first substrate 10 to the third substrate 30 are fixed to form the multilayer substrate 100. The sintered body 23 is formed in a part of the periphery of the second through hole 21. The sintered body 33 is formed in a part of the periphery of the third through hole 31.

  In the present embodiment, the first through hole 11 to the third through hole 31 are formed at different positions, and no through through hole penetrating the multilayer substrate 100 is provided. For this reason, the sintered body 23 and the sintered body 33 are separated from each other in the XY plan view. As in the first embodiment, the local thickness change of the multilayer substrate 100 can be reduced, and the pressure concentration during pressing can be reduced. Also in the present embodiment, the same effect as in the first embodiment can be obtained.

  In the present embodiment, it is preferable that one through hole is formed so as not to overlap with all other through holes. That is, it is preferable to arrange the through holes provided in one substrate so as not to overlap with the through holes provided in all other substrates. By doing in this way, it can be set as the structure where two or more through-holes do not overlap at all. It is possible to prevent two or more sintered bodies from overlapping, and to reduce pressure concentration during pressing.

  In addition, the modification of the sintered compact 23 is shown in FIG. In the present embodiment, the sintered body 23 can be formed on the entire circumference of the second through hole 21. That is, if the sintered body 23 does not overlap with the other sintered bodies 33, the sintered body 23 may be arranged so as to surround the second through hole 21. Thereby, since the area of the sintered compact 23 can be enlarged, the connection reliability between layers can be made higher.

  It is possible to combine the configuration of the second embodiment and the configuration of the first embodiment. For example, the through-through hole 1 can be configured as in the first embodiment, and the other through-holes can be configured as in the second embodiment.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Through through hole 10 1st board | substrate 11 1st through hole 12 Conductor 12a Conductive pattern 12b Conductive pattern 12c Inner wall conductor 15 Base material 20 2nd board | substrate 21 2nd through hole 22 Conductor 22a Conductive pattern 22b Conductive pattern 22c Conductor 23 Sintered body 30 Third substrate 31 Third through hole 32 Conductor 32a Conductive pattern 32b Conductive pattern 32c Conductor 33 Sintered body 40 Fourth substrate 41 Fourth through hole 42 Conductor 42a Conductive pattern 42b Conductive pattern 42c Conductor 43 Sintered body 50 Fifth substrate 51 Fifth through hole 52 Conductor 52a Conductive pattern 52b Conductive pattern 52c Conductor 53 Sintered body

Claims (6)

a multilayer substrate including n (n is an integer of 3 or more) substrates,
Conductive patterns are provided on both sides of each substrate,
The inner wall of the through hole formed in the substrate is provided with inner wall conductors connecting the conductive patterns on both sides of the substrate,
In order to connect the conductive patterns provided opposite to the two adjacent substrates, a conductive sintered body is provided between the two substrates in the periphery of the through hole,
In a plan view, the through holes provided in the n substrates are arranged so as to overlap with each other, thereby providing a through through hole penetrating the multilayer substrate,
The sintered body between the substrates is formed in a part in the circumferential direction of the through-hole,
In a plan view, a multilayer substrate having the sintered body provided between said substrate are shifted between the sintered body provided between the other substrate in the circumferential direction of the through hole. The sintered bodies are provided between (n-1) substrates provided in the multilayer substrate around the through-holes, respectively.
In a plan view, the sintered body is provided in a region obtained by dividing the periphery of the through-through hole in the circumferential direction by (n−1), so that (n−1) pieces of the sintered bodies are provided in the through-through hole. The multilayer substrate according to claim 1 , which corresponds to one circumference of the outer periphery of the substrate. The multi-layer substrate of claim 1 or 2 wherein the two substrates adjacent is welded. A method of manufacturing a multilayer substrate including n (n is an integer of 3 or more) substrates,
Preparing n substrates including through holes, conductive patterns provided on both sides, and inner wall conductors provided on inner walls of the through holes to connect the conductive patterns provided on both sides; Forming a conductive paste on the conductive pattern;
stacking n said substrates;
The conductive paste is sintered in a state in which the n stacked substrates are pressed to form a sintered body for connecting the conductive patterns provided facing two adjacent substrates. A process,
In a plan view, the through holes provided in the n substrates are arranged so as to overlap with each other, thereby providing a through through hole penetrating the multilayer substrate,
The sintered body between the substrates is formed in a part in the circumferential direction of the through-hole,
In plan view, a method for manufacturing a multilayer substrate on which the sintered body provided between said substrate are shifted in a circumferential direction of the sintered body and the through holes provided between the other substrate. The sintered bodies are provided between (n-1) substrates provided in the multilayer substrate around the through-holes, respectively.
In a plan view, the sintered body is provided in a region obtained by dividing the periphery of the through-through hole in the circumferential direction by (n−1), so that (n−1) pieces of the sintered bodies are provided in the through-through hole. The manufacturing method of the multilayer substrate according to claim 4 , which corresponds to one circumference of the outer periphery. The method for producing a multilayer substrate according to claim 4 or 5 , wherein two adjacent substrates are welded when the conductive paste is sintered.

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