Wiring circuit substrate and method for manufacturing the same

Abstract

A wiring circuit substrate (1) includes: a base insulating layer (2); a first wiring layer (7) disposed on one side in a thickness direction of the base insulating layer (2); and a cover insulating layer (3) disposed on the one side in the thickness direction of the base insulating layer (2) so as to cover the first wiring layer (7). The first wiring layer (7) includes: a first wiring portion (8) in contact with the one side of the base insulating layer; and a second wiring portion (9) in contact with the one side in the thickness direction of the first wiring portion. Both end surfaces of the second wiring portion (9) in a width direction orthogonal to the thickness direction and a transmission direction are disposed at positions inside the both end surfaces of the first wiring portion (8) in the width direction.

Description

Technical Field

[0001] This invention relates to wiring circuit boards and methods for manufacturing the same. Background Technology

[0002] Previously, a wiring circuit board was known to include: a base insulating layer; a wiring layer formed on the base insulating layer, the wiring layer having a rectangular cross-section; and a covering insulating layer covering the wiring layer (see, for example, Patent Document 1 below).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-119599 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In recent years, there has been a demand for efficient transmission of large currents in the wiring layer of circuit boards.

[0008] Therefore, the following solutions were attempted: widening the width or increasing the thickness of the routing layer to increase the cross-sectional area and reduce the resistance of the routing layer. When the space for routing layers is limited, there are situations where the width of the routing layer cannot be increased. Based on this, increasing the thickness of the routing layer was particularly explored.

[0009] However, in this case, there is a defect that the covering insulation layer is easily peeled off from both ends of the wiring in the width direction from the top.

[0010] The present invention provides a wiring circuit board capable of reducing the resistance of the wiring layer and suppressing the peeling of the covering insulating layer from the wiring layer, and a method thereof.

[0011] Solution for solving the problem

[0012] The present invention (1) includes a wiring circuit board, wherein the wiring circuit board comprises: a substrate insulating layer; a wiring layer disposed on one side of the substrate insulating layer in the thickness direction; and a cover insulating layer disposed on one side of the substrate insulating layer in the thickness direction to cover the wiring layer, the wiring layer comprising: a first wiring portion contacting the side of the substrate insulating layer in the thickness direction; and a second wiring portion contacting the side of the first wiring portion in the thickness direction, wherein the two end faces of the second wiring portion in the width direction orthogonal to the thickness direction and the transmission direction are disposed at a position closer to the inside of the width direction than the two end faces of the first wiring portion.

[0013] In this wiring circuit board, the wiring layer includes a first wiring portion and a second wiring portion. Therefore, the cross-sectional area can be increased, thereby reducing the resistance of the wiring layer.

[0014] Furthermore, the two end faces of the second wiring portion in the width direction are positioned further inward in the width direction than the two end faces of the first wiring portion. Therefore, at each of the two ends in the width direction of the wiring layer, two steps can be formed by the first wiring portion and the second wiring portion. Thus, by covering these steps with an insulating layer and achieving an anchoring effect, peeling of the insulating layer from the wiring layer can be suppressed.

[0015] The present invention (2) includes the wiring circuit board described in (1), wherein the ratio of the thickness T2 of the second wiring portion to the thickness T1 of the first wiring portion, i.e., T2 / T1, is 0.7 or more and 3.0 or less.

[0016] In this wiring circuit board, since the ratio (T2 / T1) of the thickness T2 of the second wiring portion to the thickness T1 of the first wiring portion is 0.7 or more and 3.0 or less, the cross-sectional area of ​​the wiring layer can be increased, and the anchoring effect can be reliably exerted, thus more reliably suppressing the peeling of the covering insulation layer from the wiring layer.

[0017] The present invention (3) includes the wiring circuit board described in (1) or (2), wherein the wiring layer further comprises: a third wiring portion that is in surface contact with one side of the substrate insulating layer in the thickness direction; and a fourth wiring portion that is spaced apart from the third wiring portion on one side in the thickness direction.

[0018] In this wiring circuit board, the wiring layer includes a third wiring portion and a fourth wiring portion, so the third wiring portion and the fourth wiring portion can be used for the same purpose as the first wiring portion and the second wiring portion or for different purposes. Therefore, the wiring layer can be used for a wide range of applications.

[0019] The present invention (4) includes the wiring circuit board described in (3), wherein the wiring layer comprises: a first pattern portion comprising the first wiring portion and the second wiring portion; and a second pattern portion comprising the third wiring portion and the fourth wiring portion, and is independent of the first pattern portion.

[0020] In this wiring circuit board, the wiring layer has a first pattern and a second pattern that is independent of the first pattern, so that these patterns can be used for their respective purposes.

[0021] The present invention (5) includes a method for manufacturing a wiring circuit board, which is the method for manufacturing a wiring circuit board described in (4), wherein the method for manufacturing a wiring circuit board comprises: a step of forming the substrate insulating layer; a step of forming the first wiring portion and the third wiring portion; a step of simultaneously forming the second wiring portion and the fourth wiring portion; and a step of forming the covering insulating layer.

[0022] In this method, since the second wiring portion included in the first pattern portion and the fourth wiring portion included in the second pattern portion are formed simultaneously, it is possible to easily form the second wiring portion and the fourth wiring portion included in different pattern portions in one go.

[0023] The effects of the invention

[0024] The wiring circuit board of the present invention can reduce the resistance of the wiring layer and suppress the peeling of the covering insulating layer from the wiring layer.

[0025] According to the manufacturing method of the wiring circuit board of the present invention, it is possible to easily form the second wiring portion and the fourth wiring portion containing different patterns in one step. Attached Figure Description

[0026] Figure 1 In Figure 1 A~ Figure 1 B is an enlarged view of one embodiment of the wiring circuit board of the present invention. Figure 1 A is the top view. Figure 1 B is along Figure 1 A frontal sectional view of the X-X line of A.

[0027] Figure 2 In Figure 2 A~ Figure 2 B is Figure 1 A~ Figure 1 The side sectional view of the wiring circuit board shown in B. Figure 2 A is along Figure 1 A~ Figure 1 A cross-sectional view of line B along the Y-Y line. Figure 2 B is along Figure 1 A~ Figure 1 A cross-sectional view of line Z-Z of B.

[0028] Figure 3 In Figure 3 A~ Figure 3 E is Figure 1 The diagram shown in B illustrates the manufacturing process of the wiring circuit board. Figure 3 A represents the process of preparing the base insulating layer. Figure 3 B indicates the process of forming the first wiring section and the third wiring section. Figure 3 C indicates the process of forming the first covering insulation layer. Figure 3 D indicates the process of forming the second and fourth wiring sections. Figure 3 E indicates the process of forming the second covering insulation layer.

[0029] Figure 4 yes Figure 1 A cross-sectional view of a modified example of the wiring circuit board shown in B (the first patterned portion has a second covering insulating layer).

[0030] Figure 5 yes Figure 1 A cross-sectional view of a modified example of the wiring circuit board shown in B (the form in which the second covering insulating layer contacts a portion of the side surface of the second wiring portion).

[0031] Figure 6 yes Figure 1 A cross-sectional view of a modified example of the wiring circuit board shown in B (a configuration in which the second covering insulating layer contacts a portion of the surface on one side of the first wiring portion in the thickness direction).

[0032] Figure 7 yes Figure 1 A cross-sectional view of a modified example of the wiring circuit board shown in B (a configuration where the awning portion and the second wiring portion are continuous).

[0033] Figure 8 In Figure 8 A~ Figure 8 B is Figure 1 A~ Figure 1 The modified example of the wiring circuit board shown in B (the form that has the first pattern portion but not the second pattern portion) Figure 8 A is the top view. Figure 8 B is along Figure 8 A side sectional view of line Z-Z of A.

[0034] Figure 9 In Figure 9 A~ Figure 9 E is a process diagram of another wiring circuit board manufacturing method, and is a cross-sectional view of the wiring circuit board. Figure 9 A represents the process of forming the first wiring section. Figure 9 B indicates the process of forming the second and third wiring sections. Figure 9 C indicates the process of forming the first covering insulation layer. Figure 9 D indicates the process of forming the 4th wiring section. Figure 9 E indicates the process of forming the second covering insulation layer.

[0035] Figure 10 This is a cross-sectional view of the wiring circuit board of Comparative Example 1. Detailed Implementation

[0036] <One implementation method>

[0037] Reference Figure 1 A~ Figure 2 B will be used to illustrate one embodiment of the wiring circuit board of the present invention. Furthermore, in Figure 1 In A, the covering insulation layer 3 (described later) is omitted in order to clearly show the relative position of the wiring layer 6 (described later).

[0038] The wiring circuit board 1 has a predetermined thickness and has a front-to-back direction (is) Figure 1 The top and bottom directions on the paper in A are... Figure 1 The flat strip shape extends longer in the depth direction of the paper in B. The wiring circuit board 1 includes a base insulating layer 2, a wiring layer 6 disposed on one side in the thickness direction of the base insulating layer 2, and a cover insulating layer 3 covering the wiring layer 6.

[0039] The substrate insulating layer 2 has the same shape as the wiring circuit board 1 when viewed from above. For example, insulating resins such as polyimide can be used as materials for the substrate insulating layer 2. The thickness of the substrate insulating layer 2 is, for example, 5 μm or more, and also, for example, 30 μm or less.

[0040] The wiring layer 6 includes a first wiring layer 7, a second wiring layer 10, and a third wiring layer 12. For example, copper or other conductors can be used as the material for the wiring layer 6. The wiring layer 6 extends in the front-to-back direction. That is, the direction in which the wiring layer 6 extends is the transmission direction, which is also the front-to-back direction. The shape, arrangement, and dimensions of the wiring layer 6 will be described in detail later.

[0041] The cover insulating layer 3 is disposed on one side of the base insulating layer 2 in the thickness direction. The cover insulating layer 3 covers the wiring layer 6. As a material for the cover insulating layer 3, insulating resins such as polyimide can be cited as examples.

[0042] Furthermore, the wiring circuit board 1 includes a first patterned portion 4 and a second patterned portion 5. The first patterned portion 4 is one side portion of the wiring circuit board 1 in the width direction (a direction orthogonal to the thickness direction and the front-back direction), and the second patterned portion 5 is the other side portion of the wiring circuit board 1 in the width direction. The first patterned portion 4 and the second patterned portion 5 are spaced apart from each other in the width direction. A margin portion 19 is provided between the first patterned portion 4 and the second patterned portion 5. The margin portion 19 does not contain the covering insulating layer 3 and the wiring layer 6 (described later), but only contains the base insulating layer 2.

[0043] like Figure 1 The left side diagram of B and Figure 2 As shown in A, the first patterned part 4 includes a base insulating layer 2, a first wiring layer 7, and a cover insulating layer 3.

[0044] The first wiring layer 7 is, for example, a power wiring used to transmit power current (e.g., large currents of 10mA or more, even 100mA or more). The first wiring layer 7 is an example of the first pattern.

[0045] The first wiring layer 7 has a generally rectangular shape that extends along the front-to-back direction when viewed from above. Alternatively, the first wiring layer 7 has a generally convex (inverted T) shape in a cross section orthogonal to the transmission direction of the first wiring layer 7.

[0046] like Figure 1 As shown in Figure B, the first wiring layer 7 has a first wiring portion 8 and a second wiring portion 9 with a width smaller than that of the first wiring portion 8 on one side facing the thickness direction. Preferably, the first wiring layer 7 has only the first wiring portion 8 and the second wiring portion 9.

[0047] The first wiring portion 8 is the other side portion of the first wiring layer 7 in the thickness direction. The first wiring portion 8 is disposed on one side surface of the substrate insulating layer 2 in the thickness direction. The first wiring portion 8 has a generally rectangular shape that is longer in the width direction. The entire other side surface of the first wiring portion 8 in the thickness direction is in contact with the other side surface of the substrate insulating layer 2 in the thickness direction.

[0048] The second wiring section 9 is one side portion of the first wiring layer 7 in the thickness direction. The second wiring section 9 is disposed in the middle portion (between the two ends) of the width direction of one side surface of the first wiring section 8 in the thickness direction. The second wiring section 9 has a generally rectangular shape in a cross-section orthogonal to the transmission direction of the first wiring layer 7. The entire other side surface of the second wiring section 9 does not contact the two ends in the width direction of one side surface of the first wiring section 8 in the thickness direction, but rather contacts the middle portion in the width direction of one side surface of the first wiring section 8 in the thickness direction.

[0049] Therefore, in the first wiring layer 7, the two end faces of the second wiring portion 9 in the width direction are positioned inside the width direction than the two end faces of the first wiring portion 8.

[0050] At one end of the first wiring layer 7 in the width direction, two side steps 17 are formed, which are formed by the side end face of the first wiring portion 8 and one side face in the thickness direction, and the side end face of the second wiring portion 9 and one side face in the thickness direction. At the other end of the first wiring layer 7 in the width direction, two other side steps 18 are formed, which are formed by the side end face of the first wiring portion 8 and one side face in the thickness direction, and the side end face of the second wiring portion 9 and one side face in the thickness direction.

[0051] The first wiring section 8 and the second wiring section 9 constitute the first pattern.

[0052] The thickness T1 of the first wiring portion 8 is, for example, 3 μm or more, preferably 5 μm or more, and also, for example, 40 μm or less, preferably 25 μm or less. The thickness T2 of the second wiring portion 9 is, for example, 3 μm or more, preferably 5 μm or more, and also, for example, 50 μm or less, preferably 30 μm or less. The ratio (T2 / T1) of the thickness T2 of the second wiring portion 9 to the thickness T1 of the first wiring portion 8 is, for example, 0.7 or more, preferably 0.9 or more, more preferably 1.0 or more, and also, for example, 3.0 or less, preferably 2.0 or less, more preferably 1.5 or less. The thickness T1 of the first wiring portion 8 is the length between one side of the first wiring portion 8 in the thickness direction and one side of the substrate insulating layer 2 in the thickness direction. The thickness T2 of the second wiring portion 9 is the length between one side of the second wiring portion 9 in the thickness direction and one side of the first wiring portion 8 in the thickness direction. If the cross-sectional area of ​​the first wiring layer 7 is within the above range, the anchoring effect of the covering insulation layer 3 (the second covering insulation layer 16) relative to the first wiring layer 7 can be reliably exerted, and the peeling of the covering insulation layer 3 from the first wiring layer 7 can be more reliably suppressed.

[0053] The width of the first wiring portion 8 is, for example, 10 μm or more, preferably 20 μm or more, more preferably 30 μm or more, and also, for example, 500 μm or less, preferably 250 μm or less. The width of the first wiring portion 8 is the distance between its two end faces in the width direction. If the width of the first wiring portion 8 is less than or equal to the above-mentioned upper limit, the first wiring layer 7 can be configured even in a small space.

[0054] The width of the second wiring portion 9 is, for example, 5 μm or more, preferably 15 μm or more, more preferably 20 μm or more, and also, for example, 450 μm or less, preferably 200 μm or less. The width of the second wiring portion 9 is the distance between its two end faces in the width direction. The ratio of the width of the second wiring portion 9 to the width of the first wiring portion 8 is, for example, 0.8 or less, preferably 0.6 or less, and also, for example, 0.1 or more, preferably 0.3 or more.

[0055] The thickness of the first wiring layer 7 is the sum of the thickness T1 of the first wiring section 8 and the thickness T2 of the second wiring section 9. The width of the first wiring layer 7 is the same as the width of the first wiring section 8.

[0056] Furthermore, terminals (not shown) are connected to both ends of the first wiring layer 7 in the front-back direction. The terminals are electrically connected to electrodes. Electrodes are provided in a power supply device for inputting power current to the first wiring layer 7 and a drive device for conducting power current out of the first wiring layer 7.

[0057] like Figure 1 B and Figure 2As shown in Figure A, in the first patterned portion 4, the covering insulating layer 3 includes a second covering insulating layer 16. Specifically, in this embodiment, the covering insulating layer 3 only includes the second covering insulating layer 16.

[0058] like Figure 1 As shown in the left-hand diagram of B, the second cover insulating layer 16 covers the first wiring layer 7. Specifically, the second cover insulating layer 16 contacts the portion of one side of the base insulating layer 2 near the outer side of the first wiring portion 8 in the thickness direction, the two end faces of the first wiring portion 8 in the width direction and one side face in the thickness direction, and the two end faces of the second wiring portion 9 in the width direction and one side face in the thickness direction. More specifically, the second cover insulating layer 16 contacts (closely fits) the two side steps 17 and the two side steps 18 of the first wiring layer 7. The second cover insulating layer 16 is fixed to both ends of the first wiring layer 7 in the width direction.

[0059] The length between one side of the second covering insulating layer 16 in the thickness direction and one side of the second wiring portion 9 in the thickness direction is equivalent to the thickness of the second covering insulating layer 16. The thickness of the second covering insulating layer 16 is, for example, 5 μm or more, and also, for example, 50 μm or less.

[0060] like Figure 1 The right side diagram of B and Figure 2 As shown in B, the second patterned portion 5 includes a base insulating layer 2, a second wiring layer 10, a first cover insulating layer 15, a third wiring layer 12, and a second cover insulating layer 16.

[0061] The base insulating layer 2 of the second patterned part 5 is the same as the base insulating layer 2 of the first patterned part 4.

[0062] The second wiring layer 10 is, for example, a signal wiring layer for transmitting electrical signals (e.g., weak currents less than 10mA or even less than 1mA). The second wiring layer 10 has a third wiring portion 13 with a generally rectangular shape. Preferably, the second wiring layer 10 only has the third wiring portion 13.

[0063] The third wiring portion 13 is disposed on one side of the substrate insulating layer 2 in the thickness direction. The entire other side of the third wiring portion 13 in the thickness direction is in contact with the side of the substrate insulating layer 2 in the thickness direction. The thickness T3 of the third wiring portion 13 is, for example, the same as the thickness T1 of the first wiring portion 8. The width of the third wiring portion 13 is not particularly limited; in this embodiment, for example, the width of the third wiring portion 13 is the same as the width of the second wiring portion 9.

[0064] In this embodiment, the width of the third wiring portion 13 is smaller than the width of the first wiring portion 8.

[0065] The first covering insulating layer 15 covers the third wiring portion 13 in a cross-section orthogonal to the transmission direction of the first wiring layer 7. Specifically, the first covering insulating layer 15 contacts the portion of the first insulating layer 2 near the outer side of the third wiring portion 13 on one side in the thickness direction, as well as the two end faces of the third wiring portion 13 in the width direction and one side face in the thickness direction. The length between the first insulating layer 15 and the third wiring portion 13 in the thickness direction is equivalent to the thickness of the first insulating layer 15. The thickness of the first insulating layer 15 is, for example, 5 μm or more, and also, for example, 50 μm or less.

[0066] The third wiring layer 12 is, for example, a signal wiring layer for transmitting electrical signals (e.g., weak currents less than 10mA or even less than 1mA). The third wiring layer 12 has a fourth wiring portion 14 with a generally rectangular shape. Preferably, the third wiring layer 12 only has the fourth wiring portion 14.

[0067] The fourth wiring portion 14 is disposed on one side of the first covering insulating layer 15 in the thickness direction. The entire other side of the fourth wiring portion 14 in the thickness direction is in contact with the side of the first covering insulating layer 15 in the thickness direction. When projected along the thickness direction, the fourth wiring portion 14 overlaps with the third wiring portion 13. Specifically, the top view shape of the fourth wiring portion 14 is the same as the top view shape of the third wiring portion 13. The thickness T4 of the fourth wiring portion 14 is, for example, the same as the thickness T3 of the third wiring portion 13. The width of the fourth wiring portion 14 is the same as the width of the third wiring portion 13.

[0068] The second wiring layer 10 and the third wiring layer 12 described above are examples of the second pattern. The third wiring section 13 and the fourth wiring section 14 constitute the second pattern.

[0069] The second insulating layer 16 covers the fourth wiring portion 14. Specifically, the second insulating layer 16 contacts the portion of the first insulating layer 15 near the outer side of the fourth wiring portion 14 on one side in the thickness direction, and the two end faces and one side face in the thickness direction of the fourth wiring portion 14. The length between the side face of the second insulating layer 16 in the thickness direction and the side face of the fourth wiring portion 14 in the thickness direction is equivalent to the thickness of the second insulating layer 16. The thickness of the second insulating layer 16 is, for example, 5 μm or more, and also, for example, 50 μm or less.

[0070] The first covering insulating layer 15 and the second covering insulating layer 16 are included in the covering insulating layer 3. Preferably, the covering insulating layer 3 of the second patterned portion 5 only includes the first covering insulating layer 15 and the second covering insulating layer 16.

[0071] Next, refer to Figure 3 A~ Figure 3E will be used to describe the manufacturing method of the wiring circuit board 1. The manufacturing method of the wiring circuit board 1 includes a first step of preparing a base insulating layer 2, a second step of forming a first wiring portion 8 and a third wiring portion 13, a third step of forming a first covering insulating layer 15, a fourth step of forming a second wiring portion 9 and a fourth wiring portion 14, and a fifth step of forming a second covering insulating layer 16. Steps 1 to 5 are performed sequentially.

[0072] like Figure 3 As shown in A, in the first step, for example, a photosensitive insulating resin composition is photolithographically formed to form a substrate insulating layer 2.

[0073] like Figure 3 As shown in B, in the second process, for example, the first wiring section 8 and the third wiring section 13 are formed simultaneously by pattern forming methods such as additive or subtractive methods.

[0074] In the second pattern section 5, a second wiring layer 10 (signal wiring) having a third wiring section 13 is formed.

[0075] like Figure 3 As shown in C, in the third step, for example, a photosensitive insulating resin composition is applied to one side of the substrate insulating layer 2 in the thickness direction, covering the first wiring portion 8 and the third wiring portion 13, and then photolithography is performed. As a result, a first covering insulating layer 15 covering the third wiring portion 13 is formed in the second patterned portion 5.

[0076] like Figure 3 As shown in D, in the fourth process, for example, the second wiring section 9 and the fourth wiring section 14 are formed simultaneously by pattern forming methods such as additive or subtractive methods.

[0077] Therefore, in the first pattern section 4, a first wiring layer 7 (power wiring) is formed, which includes a first wiring section 8 and a second wiring section 9. In addition, in the second pattern section 5, a third wiring layer 12 (signal wiring) is formed, which includes a fourth wiring section 14.

[0078] like Figure 3 As shown in step E, in the fifth step, for example, a photosensitive insulating resin composition is applied to one side of the base insulating layer 2 in the thickness direction and one side of the first cover insulating layer 15 in the thickness direction, covering the second wiring portion 9 and the fourth wiring portion 14, and then photolithography is performed. As a result, a second cover insulating layer 16 is formed in both the first pattern portion 4 and the second pattern portion 5. As a result, a cover insulating layer 3 having the second cover insulating layer 16 is formed in the first pattern portion 4. A cover insulating layer 3 having the first cover insulating layer 15 and the second cover insulating layer 16 is formed in the second pattern portion 5.

[0079] (Effects of one implementation method)

[0080] Furthermore, in this wiring circuit board 1, the first wiring layer 7 of the wiring layer 6 includes a first wiring portion 8 and a second wiring portion 9. Therefore, the cross-sectional area can be increased, thereby reducing the resistance of the first wiring layer 7.

[0081] Furthermore, the two end faces of the second wiring portion 9 in the width direction are positioned more inwardly in the width direction than the two end faces of the first wiring portion 8. Therefore, at one end of the first wiring layer 7 in the width direction, two side steps 17 can be formed by the first wiring portion 8 and the second wiring portion 9. At the other end of the first wiring layer 7 in the width direction, two other side steps 18 can be formed by the first wiring portion 8 and the second wiring portion 9. Therefore, by covering these steps with the insulating layer 3 and providing an anchoring effect, peeling of the insulating layer 3 from the first wiring layer 7 can be suppressed.

[0082] On the other hand, such as Figure 10 As shown in Comparative Example 1, if the two end faces of the second wiring portion 9 in the width direction are at the same position as the two end faces of the first wiring portion 8, and there is one step 17 on one side and one step 18 on the other side, the anchoring effect of the covering insulation layer 3 relative to the first wiring layer 7 will be significantly reduced. Therefore, it is not possible to sufficiently suppress the peeling of the covering insulation layer 3 from the first wiring layer 7.

[0083] In addition, in a wiring circuit board 1 of one embodiment, if the ratio (T2 / T1) of the thickness T2 of the second wiring portion 9 to the thickness T1 of the first wiring portion 8 is 0.9 or more and 2.0 or less, the area of ​​the cross section of the first wiring layer 7 can be increased, and the anchoring effect can be reliably exerted, and the peeling of the covering insulating layer 3 from the first wiring layer 7 can be more reliably suppressed.

[0084] Furthermore, in this wiring circuit board 1, the second wiring layer 10 of the wiring layer 6 includes a third wiring portion 13, and the third wiring layer 12 includes a fourth wiring portion 14. Therefore, the second wiring layer 10 including the third wiring portion 13 and the third wiring layer 12 including the fourth wiring portion 14 can be used for purposes different from the first wiring portion 8 and the second wiring portion 9, specifically for signal wiring. Therefore, the wiring layer 6 can be used for a wide range of applications.

[0085] In addition, in the wiring circuit board 1, the wiring layer 6 includes a first wiring layer 7 (first pattern) and a second wiring layer 10 and a third wiring layer 12 (second pattern) that are independent of the first wiring layer 7. Therefore, for example, the first wiring layer 7 can be used as a power supply wiring, and the second wiring layer 10 and the third wiring layer 12 can be used as signal wiring.

[0086] Additionally, in this method, such as Figure 3As shown in D, the second wiring section 9 contained in the first wiring layer 7 and the fourth wiring section 14 contained in the third wiring layer 12 are formed simultaneously, so that the second wiring section 9 and the fourth wiring section 14 contained in different patterns can be formed easily in one go.

[0087] (Modified Example)

[0088] In the following variations, the same reference numerals are used for components and processes identical to those in the above embodiment, and detailed descriptions are omitted. Furthermore, unless otherwise specified, each variation achieves the same effect as the first embodiment. Moreover, an embodiment and its variations can be appropriately combined.

[0089] like Figures 4-7 As shown, the allowance portion 19 may also include a covering insulating layer 3. In these variations, the covering insulating layer 3 of the allowance portion 19 is a first covering insulating layer 15. The first covering insulating layer 15 of the allowance portion 19 connects the first covering insulating layer 15 of the first pattern portion 4 and the first covering insulating layer 15 of the second pattern portion 5 in the width direction.

[0090] like Figure 4 As shown, in the first pattern section 4, the covering insulating layer 3 further includes a first covering insulating layer 15. That is, in the first pattern section 4, the covering insulating layer 3 includes a first covering insulating layer 15 and a second covering insulating layer 16.

[0091] The first covering insulating layer 15 contacts the portion of one side of the base insulating layer 2 in the thickness direction that is close to the outside of the first wiring portion 8 and the two end faces of the first wiring portion 8 in the width direction.

[0092] The second covering insulation layer 16 is in surface contact with one side of the second wiring portion 9 in the thickness direction.

[0093] like Figure 5 As shown, the second covering insulating layer 16 contacts one side of the thickness direction of the two end faces of the second wiring portion 9 in the width direction. On the other hand, the first covering insulating layer 15 contacts the other side of the thickness direction of the two end faces of the second wiring portion 9 in the width direction.

[0094] like Figure 6 As shown, the second covering insulating layer 16 contacts the entire length of both end faces of the second wiring portion 9 in the width direction and the portion of one side face of the first wiring portion 8 in the thickness direction near the outer side of the second wiring portion 9. On the other hand, the first covering insulating layer 15 contacts the two ends of one side face of the first wiring portion 8 in the thickness direction and both ends in the width direction.

[0095] like Figure 7As shown, a awning 20 may be continuously provided on one side of the thickness direction of both end faces in the width direction of the second wiring portion 9. The awning 20 protrudes outwards in the width direction from one side of the thickness direction of both end faces in the width direction of the second wiring portion 9. The length between the end face of one side of the awning 20 in the width direction and the end face of the other side of the awning 20 in the width direction is, for example, the same as the width of the first wiring portion 8. In this modified example, a groove 23 is formed between the awning 20 and the end face of the first wiring portion 8 in the width direction. Furthermore, the other side of the thickness direction of both end faces in the width direction of the second wiring portion 9 is positioned in the width direction further inward than the end faces in the width direction of the first wiring portion 8, forming the groove 23 together with the awning 20 and the two ends of the first wiring portion 8. The first covering insulation layer 15 is filled in the groove 23. Therefore, the covering insulation layer 3 can exert an anchoring effect based on the groove 23.

[0096] like Figure 8 A~ Figure 8 As shown in B, the wiring circuit board 1 does not have a second patterned portion 5, but has a first patterned portion 4.

[0097] The first pattern section 4 has a front region 21 and a rear region 22 facing the rear.

[0098] The front section of region 21 is along Figure 8 A~ Figure 8 The cross-section of B's ​​X-ray, and Figure 1 The left-hand diagram of B is the same. For example... Figure 1 As shown in the left side view of B, the first patterned part 4 has a base insulating layer 2, a first wiring part 8, a second wiring part 9 and a second covering insulating layer 16 in the front region 21.

[0099] The positive section of the rear region 22 is along Figure 8 A~ Figure 8 The cross-section of the Y-Y line of B, and Figure 1 The diagram on the right side of B is the same. For example... Figure 1 As shown in the right side view of B, the first patterned part 4 has a base insulating layer 2, a third wiring part 13, a first covering insulating layer 15, a fourth wiring part 14 and a second covering insulating layer 16 in the rear region 22.

[0100] like Figure 8 As shown in Figure B, the first patterned portion 4 includes a single-layer fourth wiring layer 24 comprising a first wiring portion 8 and a third wiring portion 13, and a fifth wiring layer 25 comprising a second wiring portion 9 and a fourth wiring portion 14. In the front region 21, the first wiring portion 8 and the second wiring portion 9 are in contact with each other in the thickness direction, therefore, the fourth wiring layer 24 and the fifth wiring layer 25 are electrically connected.

[0101] Similarly, in the wiring circuit board 1, as Figure 1 As shown in the left side view of B, in the front region 21, the peeling of the covering insulation layer 3 from the first wiring portion 8 and the second wiring portion 9 can be suppressed by the two side steps 17 and the two other side steps 18.

[0102] like Figure 3 As shown by the imaginary line E, the wiring circuit board 1 may also include a metal support layer 29. The metal support layer 29 is in surface contact with the other side of the substrate insulating layer 2 in the thickness direction.

[0103] Additionally, refer to Figure 9 A~ Figure 9 E illustrates other variations of the manufacturing method of the wiring circuit board of the present invention.

[0104] In one embodiment of the manufacturing method, such as Figure 3 As shown in D, the second wiring portion 9 is formed simultaneously with the fourth wiring portion 14, but for example, in this modified example, as Figure 9 As shown in B, the second wiring section 9 is formed simultaneously with the third wiring section 13.

[0105] In this variation, firstly, as Figure 9 As shown in Figure A, a base insulating layer 2 is prepared. Next, only the first wiring section 8 is formed.

[0106] Next, as Figure 9 As shown in B, the second wiring section 9 and the third wiring section 13 are formed simultaneously.

[0107] Next, as Figure 9 As shown in C, the first covering insulating layer 15 is formed to cover the second wiring portion 9 and the third wiring portion 13.

[0108] Next, as Figure 9 As shown in D, only the fourth wiring section 14 is formed.

[0109] After that, as Figure 9 As shown in E, the second covering insulation layer 16 is formed to cover only the fourth wiring portion 14.

[0110] In the first patterned portion 4 of the wiring circuit board 1 obtained by this method, the covering insulating layer 3 includes a first covering insulating layer 15.

[0111] Of the manufacturing methods of this modified example and the manufacturing methods of this embodiment, the manufacturing method of this embodiment is preferred.

[0112] If it is a manufacturing method in one implementation, then as Figure 3 As shown in B, the first wiring section 8 and the third wiring section 13 can be formed in one step. Additionally, as... Figure 3As shown in Figure D, the second wiring section 9 and the fourth wiring section 14 are formed in one step. Therefore, it is possible to achieve this in two processes ( Figure 3 B. Figure 3 D) to form wiring layer 6.

[0113] In contrast, if it is a variation of the above example, then it is possible to Figure 9 In process A, the first wiring section 8 is formed. Figure 9 In process B, the second wiring section 9 is formed. Figure 9 The fourth wiring section 14 is formed in process D. Therefore, the wiring layer 6 is formed in 3 processes, which is more time than in one embodiment.

[0114] Furthermore, the above-described invention is provided as an illustrative embodiment of the present invention, but this is merely illustrative and not intended to limit the scope of the invention. Modifications of the invention that will be apparent to those skilled in the art are contained in the foregoing claims.

[0115] Industrial availability

[0116] Wiring circuit boards are used in a variety of electronic applications.

[0117] Explanation of reference numerals in the attached figures

[0118] 1. Wiring circuit board; 2. Substrate insulating layer; 3. Cover insulating layer; 4. First patterned part; 5. Second patterned part; 6. Wiring layer; 7. First wiring layer; 8. First wiring part; 9. Second wiring part; 10. Second wiring layer; 12. Third wiring layer; 13. Third wiring part; 14. Fourth wiring part.

Claims

1. A wiring circuit board, characterized in that, The wiring circuit board has the following features: Substrate insulation layer; A wiring layer disposed on one side of the substrate insulating layer in the thickness direction; and A covering insulating layer, which is made of insulating resin, is disposed on one side of the base insulating layer in the thickness direction in a manner that covers the wiring layer. The wiring layer includes: The first pattern portion includes a first wiring portion that is in surface contact with one side of the substrate insulating layer in the thickness direction; and a second wiring portion that is in surface contact with one side of the first wiring portion in the thickness direction. and The second pattern portion, which is independent of the first pattern portion, includes a third wiring portion, which is arranged at a distance from the first pattern portion in a width direction orthogonal to the thickness direction and the transmission direction, and is in contact with a surface of the substrate insulating layer on one side in the thickness direction. And a fourth wiring portion, which is spaced apart from the third wiring portion on one side in the thickness direction. The thickness of the third wiring portion is the same as the thickness of the first wiring portion. The two end faces of the second wiring portion in the width direction are positioned inside the width direction compared to the two end faces of the first wiring portion. The covering insulation layer is in contact with the two end faces of the first wiring portion.

2. The wiring circuit board according to claim 1, characterized in that, The ratio of the thickness T2 of the second wiring portion to the thickness T1 of the first wiring portion, i.e., T2 / T1, is 0.7 or more and 3.0 or less.

3. A method for manufacturing a wiring circuit board, which is the method for manufacturing a wiring circuit board according to claim 1 or 2, characterized in that, The method for manufacturing this wiring circuit board includes: The process of forming the substrate insulating layer; The process of forming the first wiring portion and the third wiring portion; The process of simultaneously forming the second wiring section and the fourth wiring section; and The process of forming the covering insulating layer.

Images