Substrate and method for manufacturing substrate

Abstract

To provide a substrate capable of preventing disconnection of each layer and suppressing manufacturing cost, and to provide a method of manufacturing the substrate.SOLUTION: Substrate 1 includes insulating base material 10, upper conductive layer 11 and lower conductive layer 12 provided on base material 10, central through hole 13 provided to penetrate upper conductive layer 11 and lower conductive layer 12 in a vertical direction, first upper insulating layer 15 covering upper conductive layer 11, and first lower insulating layer 16 covering lower conductive layer 12. The first upper insulating layer 15 is provided with an upper through hole 15A, and the first lower insulating layer 16 is provided with a lower through hole 16A. The center through-hole 13, the upper through-hole 15A, and the lower through-hole 16A are filled with a conductive material 19, and the semiconductor device further includes a second upper insulating layer 17 provided on the first upper insulating layer 15 so as to close an opening of the upper through-hole 15A, and a second lower insulating layer 18 provided on the first lower insulating layer 16 so as to close an opening of the lower through-hole 16A.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a substrate and a method for manufacturing a substrate. [Background technology]

[0002] Conventionally, flexible multilayer substrates have been widely used as electronic devices become smaller. In multilayer substrates, circuit patterns are formed on each layer, and the circuit patterns on each layer are electrically connected by plating through holes that penetrate the substrate in the vertical direction (thickness direction) (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-176871 Summary of the Invention [Problem to be solved by the invention]

[0004] However, because conventional multilayer boards are flexible, bending deformation can cause plating to peel off from through holes, potentially resulting in disconnections in the circuit patterns of each layer. To address this issue, increasing the thickness of the plating layer could be considered to improve the strength of the plating, but this increases the manufacturing costs of the board.

[0005] The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a substrate and a method for manufacturing the substrate that can prevent breakage of each layer and reduce manufacturing costs. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the substrate according to the present invention has the following features. an insulating base material; an upper conductive layer and a lower conductive layer provided on the upper surface and the lower surface of the base substrate, respectively; a central through-hole provided to penetrate the upper conductive layer and the lower conductive layer in the vertical direction; a first upper insulating layer provided on the upper surface of the base substrate so as to cover the upper conductive layer; a first lower insulating layer provided on the lower surface of the base substrate so as to cover the lower conductive layer, an upper through-hole that faces the central through-hole in the vertical direction is provided in the first upper insulating layer; a lower through hole that faces the central through hole in the vertical direction is provided in the first lower insulating layer; a conductive material filled in the central through hole, the upper through hole, and the lower through hole; a second upper insulating layer provided on the first upper insulating layer so as to close the opening of the upper through-hole; a second lower insulating layer provided on the first lower insulating layer so as to close the opening of the lower through hole, substrate.

[0007] In order to achieve the above-mentioned object, the method for manufacturing a substrate according to the present invention has the following features. forming an upper conductive layer and a lower conductive layer on the upper and lower surfaces of an insulating base substrate, respectively; forming a central through-hole that passes through in a vertical direction from the upper conductive layer to the lower conductive layer; forming a first upper insulating layer from above the upper conductive layer, the first upper insulating layer having an upper through hole that faces the central through hole in the up-down direction; forming a first upper insulating layer from above the lower conductive layer, the first upper insulating layer having a lower through hole that faces the central through hole in the up-down direction; a step of filling the central through hole, the upper through hole, and the lower through hole with a conductive material; forming a second upper insulating layer from above the first upper insulating layer to close the opening of the upper through hole; and forming a second lower insulating layer from above the first upper insulating layer to close the opening of the lower through hole. A method for manufacturing a substrate. [Effects of the Invention]

[0008] The substrate and the method for manufacturing the substrate according to the present invention have the advantage that breaks in the wiring of each layer can be prevented and manufacturing costs can be reduced.

[0009] The present invention has been briefly described above. The details of the present invention will become clearer by reading the following detailed description of the invention (hereinafter referred to as "embodiments") with reference to the accompanying drawings. [Brief explanation of the drawings]

[0010] [Figure 1] Figure 1(a) is a cross-sectional view showing a state in which an upper conductive layer 11 and a lower conductive layer are provided on the upper and lower surfaces of a base substrate, Figure 1(b) is a cross-sectional view showing a state in which a plating layer has been provided in the central through hole from the state shown in Figure 1(a), Figure 1(c) is a cross-sectional view showing a state in which a first upper insulating layer and a first lower insulating layer have been provided from the state shown in Figure 1(b), Figure 1(d) is a cross-sectional view showing a state in which a conductive material has been filled in the central through hole from the state shown in Figure 1(c), and Figure 1(e) is a cross-sectional view showing a state in which a second upper insulating layer and a second lower insulating layer have been attached from the state shown in Figure 1(d). DETAILED DESCRIPTION OF THE INVENTION

[0011] <Embodiment> Hereinafter, a substrate and a method for manufacturing a substrate according to an embodiment of the present invention will be described with reference to the drawings.

[0012] <Board structure> First, the structure of the substrate 1 will be described. As shown in FIG. 1( e), the substrate 1 is a flexible double-sided mounting type FPC (Flexible Printed Circuit) substrate. The substrate 1 includes a base substrate 10 made of insulating polyimide (Pi), upper and lower conductive layers 11 and 12 made of copper (Cu) provided on the upper and lower surfaces of the base substrate 10, respectively, and a central through-hole 13 extending vertically through the upper and lower conductive layers 11 and 12. The upper and lower conductive layers 11 and 12 are pads for mounting circuit patterns and electronic components. The central through-hole 13 is formed by laser processing or the like to penetrate the upper and lower conductive layers 11 and 12 at predetermined positions, and is provided with a conductive plating layer 14 on its inner surface. The plating layer 14 is formed such that a cylindrical portion 14A covers the inner surface of the central through-hole 13, and an annular portion 14B covers a portion of the surface of the upper and lower conductive layers 11 and 12, thereby electrically connecting the upper and lower conductive layers 11 and 12.

[0013] The substrate 1 also includes a first upper insulating layer 15 provided on the upper surface of the base substrate 10 to cover the upper conductive layer 11, and a first lower insulating layer 16 provided on the lower surface of the base substrate 10 to cover the lower conductive layer 12. The first upper insulating layer 15 and the first lower insulating layer 16 are so-called coverlays formed by printing or the like, and cover the entire surfaces of the upper conductive layer 11 and the lower conductive layer 12 except for a portion of the annular portion 14B of the plating layer 14 and the locations of the solder pads. Therefore, in the substrate 1, the first upper insulating layer 15 is provided with an upper through-hole 15A that faces the central through-hole 13 in the vertical direction, and the first lower insulating layer 16 is provided with a lower through-hole 16A that faces the central through-hole 13 in the vertical direction.

[0014] The central through-hole 13, the upper through-holes 15A, and the lower through-holes 16A of the substrate 1 are filled with a conductive material 19. The conductive material 19 is solder, which is filled into the central through-hole 13, the upper through-holes 15A, and the lower through-holes 16A when solder is applied to the solder pads on the upper conductive layer 11 and the lower conductive layer 12 by printing or the like, and is solidified by a reflow process after electronic components are placed on the solder pads.

[0015] The substrate 1 also includes a second upper insulating layer 17 provided on the first upper insulating layer 15 so as to close the opening of the upper through hole 15A, and a second lower insulating layer 18 provided on the first lower insulating layer 16 so as to close the opening of the lower through hole 16A. The second upper insulating layer 17 and the second lower insulating layer 18 are made of insulating adhesive tape or the like, and are attached so as to close the upper through hole 15A and the lower through hole 16A, respectively.

[0016] <Substrate manufacturing method> Next, a method for manufacturing the substrate 1 will be described. First, as shown in FIG. 1(a), an upper conductive layer 11 and a lower conductive layer 12 are formed on the upper and lower surfaces of an insulating base substrate 10, respectively.

[0017] 1(b), after the step of forming a central through-hole 13 that penetrates vertically from the upper conductive layer 11 to the lower conductive layer 12, a plating layer 14 is formed. At this time, a ring portion 14B that covers the upper conductive layer 11 to a part of the lower conductive layer 12 is formed by appropriately applying masking or the like.

[0018] 1(c), the following steps are performed: forming a first upper insulating layer 15 having upper through-holes 15A that are vertically opposed to the central through-hole 13 from above the upper conductive layer 11; and forming a first lower insulating layer 16 having lower through-holes 16A that are vertically opposed to the central through-hole 13 from above the lower conductive layer 12. These steps may be performed sequentially or simultaneously.

[0019] Next, as shown in FIG. 1(d), after the process of filling the central through hole 13, the upper through hole 15A, and the lower through hole 16A with conductive material 19, the conductive material 19 is solidified by a reflow process after placing an electronic component on the solder pad.

[0020] 1(e), the substrate 1 is obtained by performing a step of forming a second upper insulating layer 17 on the first upper insulating layer 15 to close the opening of the upper through-hole 15A, and a step of forming a second lower insulating layer 18 on the first lower insulating layer 16 to close the opening of the lower through-hole 16A. These steps may be performed sequentially or simultaneously.

[0021] <Actions and Effects> As described above, according to substrate 1 of the embodiment of the present invention, central through hole 13, upper through hole 15A, and lower through hole 16A are filled with conductive material 19, and the opening of upper through hole 15A is blocked by second upper insulating layer 17, and the opening of lower through hole 16A is blocked by second lower insulating layer 18, so that conductive material 19 is reliably held in central through hole 13. Therefore, according to substrate 1 of the embodiment of the present invention, conductive material 19 is unlikely to peel off from central through hole 13 even if substrate 1 is curved and deformed, which makes it difficult for upper conductive layer 11 and lower conductive layer 12 to break.

[0022] Furthermore, according to the substrate 1 of the embodiment of the present invention, the plating layer 14 is provided on the inner surface of the central through hole 13, making it even more difficult for the conductive material 19 to peel off even when the substrate 1 is bent and deformed. In particular, according to the substrate 1 of the embodiment of the present invention, it is not necessary to thicken the plating layer 14 to prevent disconnection of the upper conductive layer 11 and the lower conductive layer 12 as in the conventional case, thereby reducing manufacturing costs. In particular, according to the substrate 1 of the embodiment of the present invention, the second upper insulating layer 17 and the second lower insulating layer 18 reliably hold the conductive material 19 within the central through hole 13, making it possible to make the plating layer 14 thinner than in the conventional case, which reduces the manufacturing costs of the substrate.

[0023] Furthermore, according to the substrate 1 of the embodiment of the present invention, since the conductive material 19 is solder, when applying solder to the pads of the upper conductive layer 11 and the lower conductive layer 12, the conductive material 19 can be filled into the central through hole 13, the upper through hole 15A and the lower through hole 16A, thereby simplifying the manufacturing process.

[0024] Furthermore, according to the method for manufacturing a substrate of an embodiment of the present invention, the method includes the steps of filling the central through hole 13, the upper through hole 15A and the lower through hole 16A with conductive material 19, forming a second upper insulating layer 17 from above the first upper insulating layer 15 to block the opening of the upper through hole 15A, and forming a second lower insulating layer 18 from above the first lower insulating layer 16 to block the opening of the lower through hole 16A, so that the desired substrate 1 can be obtained without increasing manufacturing costs.

[0025] <Other forms> The present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. are possible as appropriate. In addition, the material, shape, dimensions, number, location, etc. of each component in the above-described embodiments are arbitrary and not limited as long as the present invention can be achieved.

[0026] According to the above-described embodiment, the plating layer 14 is provided, but it is not essential to provide the plating layer 14. The plating layer 14 may not be provided, and the upper conductive layer 11 and the lower conductive layer 12 may be electrically connected by the conductive material 19.

[0027] Here, the features of the embodiments of the substrate and the method for manufacturing the substrate according to the present invention described above will be briefly summarized and listed below in [1] to [4].

[0028] [1] an insulating base substrate (10); an upper conductive layer (11) and a lower conductive layer (12) provided on the upper and lower surfaces of the base substrate (10), respectively; a central through-hole (13) extending vertically through the upper conductive layer (11) and the lower conductive layer (12); a first upper insulating layer (15) provided on the upper surface of the base substrate (10) so as to cover the upper conductive layer (11); a first lower insulating layer (16) provided on the lower surface of the base substrate (10) so as to cover the lower conductive layer (12), The first upper insulating layer (15) is provided with an upper through-hole (15A) that faces the central through-hole (13) in the vertical direction, The first lower insulating layer (16) is provided with a lower through-hole (16A) that faces the central through-hole (13) in the vertical direction, a conductive material (19) filled in the central through-hole (13), the upper through-hole (15A), and the lower through-hole (16A); a second upper insulating layer (17) provided on the first upper insulating layer (15) so as to close the opening of the upper through-hole (15A); a second lower insulating layer (18) provided on the first lower insulating layer (16) so as to close the opening of the lower through-hole (16A), Circuit board (1).

[0029] According to the substrate (1) having the above configuration [1], even if the substrate (1) is bent and deformed, the conductive material (19) is unlikely to peel off from the central through-hole (13), thereby making the upper conductive layer (11) and the lower conductive layer (12) less likely to break.

[0030] [2] In the substrate (1) described in [1] above, The device further includes a conductive plating layer (14) provided on the inner surface of the central through hole (13). Circuit board (1).

[0031] According to the substrate (1) having the configuration [2] above, the plating layer (14) is provided on the inner surface of the central through-hole (13), so that the conductive material (19) is even less likely to peel off even when the substrate is bent and deformed.

[0032] [3] In the substrate (1) described in [1] above, The conductive material (19) is solder. Circuit board (1).

[0033] According to the substrate (1) having the configuration [3] above, since the conductive material (19) is solder, when applying solder to the pads of the upper conductive layer (11) and the lower conductive layer (12), the conductive material (19) can be filled into the upper through-hole (15A) and the lower through-hole (16A), thereby simplifying the manufacturing process.

[0034] [4] forming an upper conductive layer (11) and a lower conductive layer (12) on the upper and lower surfaces of an insulating base substrate (10), respectively; forming a central through-hole (13) that penetrates vertically from the upper conductive layer (11) to the lower conductive layer (12); forming a first upper insulating layer (15) having an upper through-hole (15A) that faces the central through-hole (13) in the vertical direction from above the upper conductive layer (11); forming a first lower insulating layer (16) having a lower through-hole (16A) that faces the central through-hole (13) in the vertical direction from above the lower conductive layer (12); a step of filling the central through-hole (13), the upper through-hole (15A), and the lower through-hole (16A) with a conductive material (19); forming a second upper insulating layer (17) on the first upper insulating layer (15) to close the opening of the upper through-hole (15A); and forming a second lower insulating layer (18) on the first lower insulating layer (16) to close the opening of the lower through hole (16A). A method for manufacturing a substrate.

[0035] According to the manufacturing method of the substrate (1) having the above configuration [4], the desired substrate 1 can be obtained without increasing the manufacturing cost. [Explanation of symbols]

[0036] 1 board 10 Base material 11 Upper conductive layer 12 Lower conductive layer 13 Central through hole 14 plating layer 15 First upper insulating layer 15A upper through hole 16 First lower insulating layer 16A Lower through hole 17 Second upper insulating layer 18 Second lower insulating layer 19 Conductive materials

Claims

1. an insulating base material; an upper conductive layer and a lower conductive layer provided on the upper surface and the lower surface of the base substrate, respectively; a central through-hole provided to penetrate the upper conductive layer and the lower conductive layer in the vertical direction; a first upper insulating layer provided on the upper surface of the base substrate so as to cover the upper conductive layer; a first lower insulating layer provided on the lower surface of the base substrate so as to cover the lower conductive layer, an upper through-hole that faces the central through-hole in the vertical direction is provided in the first upper insulating layer; a lower through-hole that faces the central through-hole in the vertical direction is provided in the first lower insulating layer; a conductive material filled in the central through hole, the upper through hole, and the lower through hole; a second upper insulating layer provided on the first upper insulating layer so as to close the opening of the upper through-hole; a second lower insulating layer provided on the first lower insulating layer so as to close the opening of the lower through hole, substrate.

2. The substrate according to claim 1 , The central through hole further includes a conductive plating layer provided on an inner surface thereof. substrate.

3. The substrate according to claim 1 , The conductive material is solder. substrate.

4. forming an upper conductive layer and a lower conductive layer on the upper and lower surfaces of an insulating base substrate, respectively; forming a central through-hole that passes through in a vertical direction from the upper conductive layer to the lower conductive layer; forming a first upper insulating layer from above the upper conductive layer, the first upper insulating layer having an upper through hole that faces the central through hole in the vertical direction; forming a first upper insulating layer from above the lower conductive layer, the first upper insulating layer having a lower through hole that faces the central through hole in the vertical direction; a step of filling the central through hole, the upper through hole, and the lower through hole with a conductive material; forming a second upper insulating layer from above the first upper insulating layer to close the opening of the upper through hole; and forming a second lower insulating layer from above the first upper insulating layer to close the opening of the lower through hole. A method for manufacturing a substrate.

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