Wired circuit board

Abstract

To provide a wiring circuit board capable of easily adjusting elasticity of a wiring part in a thickness direction.SOLUTION: The wired circuit substrate 1 includes a wire portion 2 and a first support portion 3A supporting one end portion of the wire portion 2. The wire portion 2 has a metallic support layer 11, a conductive layer 12, a first insulating layer 13, and a wire 143A. The ratio (W1 / T1) of the thickness T1 of the metallic support layer 11 to the breadth W1 of the metallic support layer 11 is less than 1. The conductive layer 12 is disposed on the one side surface S1 of the metallic support layer 11 in the thickness direction of the metallic support layer 11.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a printed circuit board. [Background technology]

[0002] BACKGROUND ART Conventionally, a wired circuit board is known that includes a plurality of wiring bodies and a connector that connects the ends of the plurality of wiring bodies (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-212656 Summary of the Invention [Problem to be solved by the invention]

[0004] In a wired circuit board such as that described in Patent Document 1, when a first electronic component is fixed to one connecting body and the other connecting body is fixed to a second electronic component, it may be desirable to support the first electronic component so that it can move elastically in the thickness direction of the wired circuit board relative to the second electronic component. In this case, it is necessary to adjust the elasticity of the wiring portion.

[0005] The present invention provides a wired circuit board in which the elasticity of the wiring portion in the thickness direction can be easily adjusted. [Means for solving the problem]

[0006] The present invention [1] includes a wired circuit board having wiring extending in a first direction, and comprising a wiring portion extending in the first direction and a first support portion supporting one end of the wiring portion in the first direction, wherein the wiring portion has a metal support layer, a conductor layer arranged on one surface of the metal support layer in a thickness direction of the metal support layer, the wiring arranged on one side of the conductor layer in the thickness direction, and an insulating layer arranged between the conductor layer and the wiring in the thickness direction, and wherein the ratio of the thickness of the metal support layer to the dimension of the metal support layer in a second direction perpendicular to both the thickness direction and the first direction is less than 1.

[0007] According to this configuration, in the wiring portion, the ratio of the thickness of the metal support layer to the dimension of the metal support layer in the second direction is less than 1.

[0008] Therefore, movement of the wiring portion in the thickness direction can be permitted while suppressing movement of the wiring portion in the second direction.

[0009] The wiring portion has a metal support layer and a conductor layer disposed on one surface of the metal support layer in the thickness direction.

[0010] Therefore, the metal support layer ensures the elasticity of the wiring portion in the thickness direction, while the conductor layer can adjust the elasticity of the wiring portion in the thickness direction.

[0011] As a result, the elasticity of the wiring portion in the thickness direction can be easily adjusted.

[0012] The present invention [2] includes the wired circuit board according to the above [1], wherein the thickness of the metal support layer is greater than 30 μm.

[0013] With this configuration, the elasticity of the wiring portion in the thickness direction can be ensured.

[0014] The present invention [3] includes the wired circuit board according to the above [1] or [2], wherein the thickness of the conductor layer is 1 μm or more.

[0015] With this configuration, the elasticity of the wiring portion in the thickness direction can be adjusted.

[0016] The present invention [4] includes the wired circuit board of any one of the above [1] to [3], wherein the ratio of the thickness of the conductor layer to the thickness of the metal support layer is 1 / 30 to 1 / 3.

[0017] According to this configuration, the elasticity of the wiring portion in the thickness direction can be adjusted while ensuring the elasticity of the wiring portion in the thickness direction.

[0018] The present invention [5] includes the wired circuit board of any one of the above [1] to [4], wherein the ratio of the dimension of the conductor layer in the second direction to the dimension of the metal support layer in the second direction is 1 / 2 or more.

[0019] With this configuration, the elasticity of the wiring portion in the thickness direction can be adjusted.

[0020] The present invention [6] includes the wired circuit board of any one of the above [1] to [5], further comprising a second support portion that supports the other end of the wiring portion in the first direction.

[0021] The present invention [7] includes the wired circuit board of any one of the above [1] to [6], which comprises a first circuit pattern having the wiring and a first terminal connected to the wiring, and a second circuit pattern having a second terminal connected to the conductor layer and independent from the first circuit pattern.

[0022] According to this configuration, it is possible to use the conductor layer to design a circuit independent of the first circuit pattern.

[0023] Therefore, the degree of freedom in circuit design can be increased while the elasticity of the wiring portion in the thickness direction can be adjusted. [Effects of the Invention]

[0024] According to the wired circuit board of the present invention, the elasticity of the wiring portion in the thickness direction can be easily adjusted. [Brief explanation of the drawings]

[0025] [Figure 1] Fig. 1 is a plan view of a printed circuit board according to one embodiment of the present invention, in which the second insulating layer is omitted. [Figure 2] Fig. 2A is a cross-sectional view taken along line AA of the printed circuit board shown in Fig. 1. Fig. 2B is a cross-sectional view taken along line BB of the printed circuit board shown in Fig. 1. [Figure 3] 3A and 3B are diagrams illustrating the mounting state of the wired circuit board shown in FIG. 2A. Fig. 3A shows a state in which a first electronic component is fixed to a first support portion and a second electronic component is fixed to a second support portion. Fig. 3B shows a state in which the first electronic component has moved in the thickness direction relative to the second electronic component. [Figure 4] 4A to 4D are process diagrams illustrating a method for manufacturing the wired circuit board shown in FIG. 2B. Fig. 4A shows a conductor layer forming process. Fig. 4B shows a first insulating layer forming process. Fig. 4C shows a circuit pattern forming process. Fig. 4D shows a second insulating layer forming process. [Figure 5] FIG. 5 is a plan view of the printed circuit board of the modified example (1). [Figure 6] FIG. 6 is a plan view of the printed circuit board of the modified example (2). [Figure 7] FIG. 7 is a plan view of the printed circuit board of the modified example (3). [Figure 8] 8 is a cross-sectional view taken along CC of the printed circuit board shown in FIG. [Figure 9] 9A and 9B are process diagrams illustrating the conductive layer forming step in the method for producing a wired circuit board according to variant (4). Fig. 9A shows the step of preparing a metal-clad laminate. Fig. 9B shows the step of etching the metal-clad laminate to form a conductive layer. DETAILED DESCRIPTION OF THE INVENTION

[0026] 1. Wiring circuit board As shown in FIG. 1, the wired circuit board 1 includes a wiring portion 2 and a plurality of support portions 3 (first support portions 3A and second support portions 3B in this embodiment).

[0027] The wiring portion 2 is disposed between the first support portion 3A and the second support portion 3B in the first direction. The wiring portion 2 extends in the first direction. More specifically, the wiring portion 2 has a width in the second direction and extends in the first direction. Wiring portions 143A and 143B, which will be described later, extend in the first direction in the wiring portion 2. That is, the wiring portion 2 has a width in the second direction and extends in the direction in which the wiring portions 143A and 143B extend. The first direction is perpendicular to the thickness direction of the wired circuit board 1. The second direction is perpendicular to both the thickness direction and the first direction. One end of the wiring portion 2 in the first direction is connected to the first support portion 3A. The other end of the wiring portion 2 in the first direction is connected to the second support portion 3B. The shape of the wiring portion 2 is not limited. The wiring portion 2 may be linear or curved. At least a portion of the wiring portions 143A and 143B is disposed in the wiring portion 2.

[0028] The first support portion 3A and the second support portion 3B are arranged at an interval from each other in the first direction. The shapes of the first support portion 3A and the second support portion 3B are not limited. The first support portion 3A supports one end portion of the wiring portion 2 in the first direction. Terminals 141A and 141B, which will be described later, may be arranged on the first support portion 3A. The second support portion 3B supports the other end portion of the wiring portion 2 in the first direction. Terminals 142A and 142B, which will be described later, may be arranged on the second support portion 3B.

[0029] As shown in FIG. 2A, the wired circuit board 1 includes a metal support layer 11, a conductor layer 12, a first insulating layer 13, a circuit pattern 14, and a second insulating layer 15.

[0030] (1) Metal support layer Metal support layer 11 is disposed on wiring portion 2 and support portion 3 (first support portion 3A and second support portion 3B). That is, wiring portion 2 has metal support layer 11. Metal support layer 11 supports first insulating layer 13, circuit pattern 14, and second insulating layer 15.

[0031] The Young's modulus of the metal support layer 11 is, for example, 100 GPa or more, preferably 130 GPa or more, and more preferably 170 GPa or more. When the Young's modulus of the metal support layer 11 is equal to or greater than the above lower limit, the elasticity of the wiring portion 2 in the thickness direction can be ensured. The Young's modulus of the metal support layer 11 is, for example, 250 GPa or less, preferably 210 GPa or less. When the Young's modulus of the metal support layer 11 is equal to or less than the above upper limit, the flexibility of the wiring portion 2 in the thickness direction can be ensured. The Young's modulus of the metal support layer 11 is, for example, 100 GPa to 250 GPa, preferably 130 GPa to 210 GPa, and more preferably 170 GPa to 210 GPa. When the Young's modulus of the metal support layer 11 is within the above range, the elasticity of the wiring portion 2 and the flexibility of the wiring portion 2 can both be achieved in the thickness direction.

[0032] Examples of materials for the metal support layer 11 include copper, nickel, cobalt, titanium, iron, and alloys thereof. Examples of alloys include copper alloys and stainless steel. A preferred material for the metal support layer 11 is stainless steel.

[0033] As shown in FIG. 2B , the thickness T1 of the metal support layer 11 is, for example, greater than 30 μm, preferably greater than or equal to 35 μm. When the thickness T1 of the metal support layer 11 is equal to or greater than the above lower limit, the elasticity of the wiring portion 2 in the thickness direction can be ensured. The thickness T1 of the metal support layer 11 is, for example, 100 μm or less, preferably 90 μm or less. When the thickness T1 of the metal support layer 11 is equal to or less than the above upper limit, the flexibility of the wiring portion 2 in the thickness direction can be ensured. The thickness T1 of the metal support layer 11 is, for example, greater than 30 μm and 100 μm or less, preferably 35 μm to 90 μm. When the thickness T1 of the metal support layer 11 is within the above range, both the elasticity of the wiring portion 2 and the flexibility of the wiring portion 2 in the thickness direction can be achieved.

[0034] The width W1 of the metal support layer 11 (the dimension of the metal support layer 11 in the second direction) is larger than the thickness T1 of the metal support layer 11. The width W1 of the metal support layer 11 is, for example, larger than 30 μm, preferably 50 μm or more, and more preferably 100 μm or more. When the width W1 of the metal support layer 11 is equal to or larger than the above-mentioned lower limit, the rigidity of the wiring portion 2 in the second direction can be ensured. The upper limit of the width W1 of the metal support layer 11 is not limited. The width W1 of the metal support layer 11 is, for example, 1000 μm or less, preferably 800 μm or less.

[0035] The ratio (T1 / W1) of the thickness T1 of the metal support layer 11 to the width W1 of the metal support layer 11 is less than 1, preferably 0.5 or less. When the ratio (T1 / W1) is equal to or greater than the above-mentioned lower limit, movement of the wiring portion 2 in the second direction is suppressed while movement of the wiring portion 2 in the thickness direction is permitted. The lower limit of the ratio (T1 / W1) is not limited. The ratio (T1 / W1) is, for example, 0.01 or more, preferably 0.02 or more.

[0036] (2) Conductor layer As shown in FIG. 2A, the conductor layer 12 is disposed on the wiring portion 2 and the support portion 3 (first support portion 3A and second support portion 3B). That is, the wiring portion 2 has the conductor layer 12. The conductor layer 12 reinforces the metal support layer 11. The conductor layer 12 is disposed on one surface S1 of the metal support layer 11 in the thickness direction of the metal support layer 11. The conductor layer 12 is preferably disposed on one surface S1 of the metal support layer 11 via a bonding layer that bonds the metal support layer 11 and the conductor layer 12. In other words, a bonding layer is preferably disposed between the metal support layer 11 and the conductor layer 12. The bonding layer is made of a metal. The bonding layer is, for example, a sputtering layer. Examples of materials for the bonding layer include chromium, nickel, titanium, and alloys thereof. The conductor layer 12 does not have a wiring pattern.

[0037] The conductor layer 12 overlaps the entire circuit pattern 14 in the thickness direction. The conductivity of the conductor layer 12 is higher than that of the metal support layer 11. Therefore, the transmission loss of the circuit pattern 14 can be reduced. Examples of materials for the conductor layer 12 include copper, silver, gold, iron, aluminum, chromium, and alloys thereof. The conductor layer 12 is preferably made of copper. The conductor layer 12 is a plated layer. Therefore, the thickness T2 (see FIG. 2B) of the conductor layer 12 can be easily adjusted. Therefore, the elasticity of the wiring portion 2 in the thickness direction can be more easily adjusted.

[0038] 2B, the thickness T2 of the conductor layer 12 is, for example, 1 μm or more, preferably 2 μm or more. When the thickness T2 of the conductor layer 12 is equal to or greater than the above-mentioned lower limit, the conductivity of the conductor layer 12 can be ensured while adjusting the elasticity of the wiring portion 2 in the thickness direction. The thickness T2 of the conductor layer 12 is, for example, 30 μm or less, preferably 20 μm or less. When the thickness T2 of the conductor layer 12 is equal to or less than the above-mentioned upper limit, the flexibility of the wiring portion 2 in the thickness direction can be ensured.

[0039] The ratio (T2 / T1) of the thickness T2 of the conductor layer 12 to the thickness T1 of the metal support layer 11 is, for example, 1 / 30 to 1 / 3, or preferably 1 / 15 to 1 / 4. When the ratio (T2 / T1) is within the above range, the elasticity of the wiring portion 2 in the thickness direction can be adjusted while ensuring the conductivity of the conductive layer 12.

[0040] As shown in FIGS. 2A and 2B, the conductor layer 12 covers the entire one-side surface S1 of the metal support layer 11, excluding the outer peripheral edge E of the metal support layer 11. The conductor layer 12 may cover the entire one-side surface S1 of the metal support layer 11, including the outer peripheral edge E of the metal support layer 11. As shown in FIG. 2B, in the wiring portion 2, the ratio (W2 / W1) of the width W2 of the conductor layer 12 (the dimension of the conductor layer 12 in the second direction) to the width W1 of the metal support layer 11 (the dimension of the metal support layer 11 in the second direction) is, for example, 1 / 2 or more, preferably 2 / 3 or more, more preferably 4 / 5 or more, and even more preferably 9 / 10 or more. The width W2 of the conductor layer 12 may be the same as the width W1 of the metal support layer 11. The ratio (W2 / W1) is, for example, 1 or less, preferably 99 / 100 or less.

[0041] (3) First insulating layer As shown in FIG. 2A, the first insulating layer 13 is disposed on the wiring portion 2 and the support portion 3 (first support portion 3A, second support portion 3B). That is, the wiring portion 2 has the first insulating layer 13. The first insulating layer 13 is disposed on one side of the metal support layer 11 in the thickness direction. The first insulating layer 13 is disposed on one surface S1 of the metal support layer 11 in the thickness direction. The first insulating layer 13 covers the conductor layer 12. The first insulating layer 13 is disposed between the conductor layer 12 and the circuit pattern 14 in the thickness direction. That is, as shown in FIG. 2B, the first insulating layer 13 of the wiring portion 2 is disposed between the conductor layer 12 and the wirings 143A and 143B in the thickness direction. The first insulating layer 13 insulates the conductor layer 12 from the circuit pattern 14.

[0042] Preferably, a protective metal layer for protecting the metal support layer 11 and the conductor layer 12 is disposed between the metal support layer 11 and the first insulating layer 13, and between the conductor layer 12 and the first insulating layer 13. The protective metal layer is made of a metal. The protective metal layer is, for example, a sputtering layer. Examples of materials for the protective metal layer include chromium, nickel, titanium, and alloys thereof.

[0043] The first insulating layer 13 is made of a resin. Examples of the resin include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester. Preferably, the first insulating layer 13 is made of polyimide.

[0044] The thickness of the first insulating layer 13 is in the range of, for example, 1 μm to 30 μm, or preferably 3 μm to 25 μm.

[0045] (4) Circuit pattern The circuit pattern 14 is disposed on one side of the conductor layer 12 in the thickness direction. That is, in the wiring section 2, the wirings 143A and 143B are disposed on one side of the conductor layer 12 in the thickness direction. The circuit pattern 14 is disposed away from the conductor layer 12 in the thickness direction. The circuit pattern 14 is independent from the conductor layer 12. The circuit pattern 14 is disposed on one side of the first insulating layer 13 in the thickness direction. The circuit pattern 14 is disposed on one surface of the first insulating layer 13 in the thickness direction. The circuit pattern 14 is disposed on the opposite side of the conductor layer 12 with respect to the first insulating layer 13 in the thickness direction. The circuit pattern 14 is made of a metal. Examples of metals include copper, silver, gold, iron, aluminum, chromium, and alloys thereof. The circuit pattern 14 is preferably made of copper. The shape of the circuit pattern 14 is not limited.

[0046] As shown in FIG. 1, the circuit pattern 14 has a plurality of terminals 141A and 141B, a plurality of terminals 142A and 142B, and a plurality of wirings 143A and 143B.

[0047] (4-1) Terminal The terminals 141A and 141B are arranged on the first support portion 3A. Each of the terminals 141A and 141B has a substantially rectangular shape. In this embodiment, the terminals 141A and 141B are aligned in the second direction. The terminals 141A and 141B are arranged at an interval from each other in the second direction. The direction in which the terminals 141A and 141B are aligned is not limited to the second direction. The terminal 141A is connected to one end of the wiring 143A. The terminal 141B is connected to one end of the wiring 143B.

[0048] The terminals 142A and 142B are arranged on the second support portion 3B. Each of the terminals 142A and 142B has a substantially rectangular shape. The terminals 142A and 142B are aligned in the second direction. The terminals 142A and 142B are arranged at an interval from each other in the second direction. Note that the direction in which the terminals 142A and 142B are aligned is not limited to the second direction. The terminal 142A is connected to the other end of the wiring 143A. The terminal 142B is connected to the other end of the wiring 143B.

[0049] (4-2) Wiring At least a portion of each of the wirings 143A and 143B is arranged in the wiring section 2. That is, the wiring section 2 has the wirings 143A and 143B. Each of the wirings 143A and 143B extends in a first direction in the wiring section 2. The wirings 143A and 143B are aligned in a second direction in the wiring section 2. The wirings 143A and 143B are arranged at an interval from each other in the second direction. The wiring 143A electrically connects the terminal 141A and the terminal 142A. The wiring 143B electrically connects the terminal 141B and the terminal 142B.

[0050] The thickness of each of the wirings 143A and 143B is in the range of, for example, 5 μm to 50 μm, or preferably 7 μm to 45 μm. (5) Second insulating layer 2A, the second insulating layer 15 is disposed at least on the wiring portion 2. That is, the wiring portion 2 has the second insulating layer 15. The second insulating layer 15 may also be disposed on the support portion 3 (first support portion 3A, second support portion 3B) as needed. The second insulating layer 15 does not cover the terminals 141A, 141B, 142A, and 142B.

[0051] As shown in FIG. 2B, the second insulating layer 15 covers all of the wirings 143A and 143B. The second insulating layer 15 is disposed on the first insulating layer 13 in the thickness direction. The second insulating layer 15 is made of a resin. Examples of the resin include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester. Preferably, the second insulating layer 15 is made of polyimide.

[0052] The second insulating layer 15 has a thickness of, for example, 1 μm to 30 μm, or preferably 3 μm to 25 μm.

[0053] 2. Mounting condition of wiring circuit board Next, the mounting state of the wired circuit board 1 will be described.

[0054] As shown in Fig. 3A, the wired circuit board 1 is used to electrically connect a first electronic component P1 and a second electronic component P2. For example, the first electronic component P1 is fixed to a first support portion 3A. The wired circuit board 1 is fixed to the second electronic component P2 at a second support portion 3B. The wiring portion 2 is disposed between the first electronic component P1 and the second electronic component P2.

[0055] As shown in FIG. 3B, the first electronic component P1 is movable in the thickness direction relative to the second electronic component P2 against the elasticity of the wiring portion 2.

[0056] 3. Manufacturing method of printed circuit board Next, a method for manufacturing the wired circuit board 1 will be described.

[0057] The method for manufacturing the wired circuit board 1 includes a conductor layer forming step (see FIG. 4A), a first insulating layer forming step (see FIG. 4B), a circuit pattern forming step (see FIG. 4C), a second insulating layer forming step (see FIG. 4D), and an exterior processing step (see FIG. 2B).

[0058] (1) Conductor layer formation process As shown in FIG. 4A, in the conductor layer forming step, a conductor layer 12 is formed on one surface of a substrate M made of metal.

[0059] Specifically, first, the above-described bonding layer is formed on one surface of the substrate M in the thickness direction. The bonding layer is formed by, for example, sputtering.

[0060] Next, the bonding layer is covered with a plating resist.

[0061] Next, the plating resist is exposed to light and developed, whereby the plating resist is removed from the area where the conductor layer 12 is to be formed, exposing the bonding layer in the area where the conductor layer 12 is to be formed. On the other hand, the plating resist remains in the area where the conductor layer 12 is not to be formed.

[0062] Next, the conductor layer 12 is formed on the exposed bonding layer by electrolytic plating. After the electrolytic plating is completed, the plating resist is peeled off.

[0063] As a result, the conductor layer 12 is formed on the substrate M.

[0064] (2) First insulating layer formation process Next, as shown in FIG. 4B, in the first insulating layer forming step, a first insulating layer 13 is formed on one surface of the base material M.

[0065] More specifically, in the first insulating layer forming step, first, the protective metal layer is formed in the thickness direction on one surface of the base material M and the conductor layer 12. The protective metal layer is formed by, for example, sputtering.

[0066] Next, a photosensitive resin solution (varnish) is applied onto the substrate M and the conductor layer 12 and dried to form a photosensitive resin coating. Next, the photosensitive resin coating is exposed to light and developed. This results in the first insulating layer 13.

[0067] (3) Circuit pattern formation process Next, as shown in FIG. 4C, in the circuit pattern forming step, a circuit pattern 14 is formed on the first insulating layer 13.

[0068] Specifically, first, a seed layer is formed on one surface of the first insulating layer 13 and one surface of the substrate M in the thickness direction. The seed layer is formed by, for example, sputtering. Examples of materials for the seed layer include chromium, copper, nickel, titanium, and alloys thereof.

[0069] The seed layer is then coated with a plating resist.

[0070] Next, the plating resist is exposed to light and developed, which removes the plating resist from the area where the circuit pattern 14 is to be formed, exposing the seed layer in the area where the circuit pattern 14 is to be formed. On the other hand, the plating resist remains in the area where the circuit pattern 14 is not to be formed.

[0071] Next, the circuit pattern 14 is formed on the exposed seed layer by electrolytic plating. After the electrolytic plating is completed, the plating resist is stripped off, and the seed layer exposed by the stripping of the plating resist is removed by etching.

[0072] As a result, a circuit pattern 14 is formed on the first insulating layer 13.

[0073] (4) Second insulating layer formation process Next, as shown in FIG. 4D, in the second insulating layer forming step, second insulating layer 15 is formed on first insulating layer 13.

[0074] More specifically, in the second insulating layer forming process, a photosensitive resin solution (varnish) is first applied onto the substrate M, the first insulating layer 13, and the circuit pattern 14 and then dried to form a photosensitive resin coating.

[0075] Next, the photosensitive resin coating is exposed to light and developed, thereby forming second insulating layer 15 on first insulating layer 13.

[0076] (5) External shape processing process Next, as shown in FIG. 2B, in the contour processing step, the substrate M is etched to form the contour of the metal support layer 11.

[0077] In this way, the above-described wired circuit board 1 is obtained.

[0078] 4. Effects (1) In the wired circuit board 1, the ratio (T1 / W1) of the thickness T1 of the metal support layer 11 to the width W1 of the metal support layer 11 in the wiring portion 2 is less than 1, as shown in FIG. 2B.

[0079] Therefore, movement of the wiring portion 2 in the thickness direction can be permitted while movement of the wiring portion 2 in the second direction is suppressed.

[0080] The wiring portion 2 has a metal support layer 11 and a conductor layer 12 disposed on one surface S1 of the metal support layer 11 in the thickness direction.

[0081] Therefore, the metal support layer 11 ensures the elasticity of the wiring portion 2 in the thickness direction, while the conductor layer 12 can adjust the elasticity of the wiring portion 2 in the thickness direction.

[0082] As a result, the elasticity of the wiring portion 2 in the thickness direction can be easily adjusted.

[0083] (2) According to the wired circuit board 1, the thickness T1 of the metal support layer 11 is greater than 30 μm.

[0084] Therefore, the elasticity of the wiring portion 2 in the thickness direction can be ensured.

[0085] (3) According to the wired circuit board 1, the thickness T2 of the conductor layer 12 is 1 μm or more.

[0086] Therefore, the elasticity of the wiring portion 2 in the thickness direction can be adjusted.

[0087] (4) In the wired circuit board 1, the ratio (T2 / T1) of the thickness T2 of the conductor layer 12 to the thickness T1 of the metal support layer 11 is 1 / 30 to 1 / 3.

[0088] Therefore, the elasticity of the wiring portion 2 in the thickness direction can be adjusted while ensuring the elasticity of the wiring portion 2 in the thickness direction.

[0089] (5) In the wired circuit board 1, the ratio (W2 / W1) of the width W2 of the conductor layer 12 to the width W1 of the metal support layer 11 is 1 / 2 or more.

[0090] Therefore, the elasticity of the wiring portion 2 in the thickness direction can be adjusted.

[0091] 5. Variations Next, a modified example will be described. In the modified example, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0092] (1) The wired circuit board 1 may have three or more support portions 3. For example, as shown in Fig. 5, the wired circuit board 1 may have a third support portion 3C in addition to the first support portion 3A and second support portion 3B described above. In this case, the wired circuit board 1 has a plurality of wiring portions 2A and 2B.

[0093] Each of the wirings 143A and 143B extends from the first support portion 3A, through the third support portion 3C, to the second support portion 3B. A middle portion of each of the wirings 143A and 143B is disposed on the third support portion 3C.

[0094] The third support portion 3C is disposed between the first support portion 3A and the second support portion 3B in the first direction. The third support portion 3C supports the other end of the wiring portion 2A and one end of the wiring portion 2B. The wiring portions 2A and 2B have the same structure as the wiring portion 2 of the above-described embodiment.

[0095] In this modification, the middle portions of the wirings 143A and 143B can be supported by the third support portion 3C.

[0096] (2) As shown in FIG. 6 , the terminals 141A and 141B do not have to be arranged on the first support portion 3A. The terminals 142A and 142B do not have to be arranged on the second support portion 3B. The first support portion 3A may be arranged between the terminals 141A and 141B and the wiring portion 2 in the first direction. The second support portion 3B may be arranged between the terminals 142A and 142B and the wiring portion 2 in the first direction. Each of the first support portion 3A and the second support portion 3B may have a through hole 20. A fastener such as a screw or a pin passes through the through hole 20.

[0097] (3) As shown in FIGS. 7 and 8, the wired circuit board 1 may include the above-mentioned circuit pattern 14 (first circuit pattern) and a second circuit pattern 30 independent from the circuit pattern 14.

[0098] The second circuit pattern 30 has a terminal 31 and a terminal 32. The second circuit pattern 30 functions as an electric circuit independent of the circuit pattern 14 by electrically connecting the terminal 31 and the terminal 32 via the conductor layer 12 (see FIG. 8).

[0099] As shown in Fig. 7, the terminal 31 is disposed on, for example, the second support portion 3B. The terminal 31 has, for example, a substantially rectangular shape. The position and shape of the terminal 31 are not limited. As shown in Fig. 8, the terminal 31 is disposed on one side of the first insulating layer 13 in the thickness direction. The terminal 31 is electrically connected to the conductor layer 12 through a through hole 13A in the first insulating layer 13.

[0100] As shown in FIG. 7 , the terminal 32 is disposed apart from the terminal 31 in the first direction. For example, the terminal 32 may be disposed on the opposite side of the wiring portion 2 with respect to the first support portion 3A in the first direction. The terminal 32 may protrude from the first support portion 3A in the first direction. The terminal 32 may have a generally rectangular columnar shape. The position and shape of the terminal 32 are not limited. As shown in FIG. 8 , the terminal 32 is continuous with the metal support layer 11 and the conductor layer 12. This allows the terminal 32 to be electrically connected to the conductor layer 12. The terminal 32 may have a metal layer 321 continuous with the metal support layer 11 and a terminal conductor layer 322 continuous with the conductor layer 12. The metal layer 321 is made of, for example, the same material as the metal support layer 11. The terminal conductor layer 322 is made of, for example, the same material as the conductor layer 12.

[0101] According to this modification, the conductor layer 12 can be used to design a circuit independent of the first circuit pattern.

[0102] Therefore, the degree of freedom in circuit design can be increased while the elasticity of the wiring portion 2 in the thickness direction can be adjusted.

[0103] (4) The method for forming the conductor layer 12 is not limited to plating. For example, in the conductor layer forming step described above, the conductor layer 12 may be formed by etching the metal-clad laminate.

[0104] 9A, a metal-clad laminate 100 is prepared in which a metal layer M2 is formed on a metal substrate M1. The substrate M1 is made of the material of the metal support layer 11 described above. The metal layer M2 is made of the material of the conductor layer 12 described above.

[0105] Next, the metal layer M2 is covered with an etching resist.

[0106] Next, the etching resist is exposed to light and developed, whereby the etching resist remains in the areas where the conductor layer 12 is to be formed and is removed in the areas where the conductor layer 12 is not to be formed.

[0107] Next, the metal layer M2 is removed by an etching solution from the portion where the conductor layer 12 is not formed. After the etching is completed, the etching resist is peeled off.

[0108] As a result, the conductor layer 12 is formed on the substrate M1, as shown in FIG. 9B.

[0109] Thereafter, similarly to the above-described embodiment, the first insulating layer forming step (see FIG. 4B), the circuit pattern forming step (see FIG. 4C), the second insulating layer forming step (see FIG. 4D), and the outer shape processing step (see FIG. 2B) are carried out in this order to obtain the wired circuit board 1.

[0110] (5) The above-described terminal 141A may have multiple conductor layers. For example, the terminal 141A may have a first conductor layer and a second conductor layer. The first conductor layer is disposed on the first insulating layer 13. The wiring 143A is connected to the first conductor layer of the terminal 141A. The material of the first conductor layer may be, for example, the same material as the above-described circuit pattern 14. The second conductor layer is disposed on the first conductor layer. The second conductor layer may be made of the same material as the first conductor layer. The second conductor layer may be made of a different material (e.g., solder) from the first conductor layer.

[0111] Furthermore, the terminal 141A described above may have a coating layer that coats the surface of the conductor layer. The coating layer has at least a surface layer. The surface layer is made of, for example, gold. The surface layer may be an electroless gold plating layer. The coating layer preferably has an intermediate layer. The coating layer does not have to have an intermediate layer. The intermediate layer is disposed between the conductor layer and the surface layer. The intermediate layer is made of, for example, nickel. The intermediate layer may be an electroless nickel plating layer.

[0112] The same applies to the terminals 141B, 142A, and 142B.

[0113] (6) The above-described modifications (1) to (5) can also provide the same effects as the above-described embodiment. [Explanation of symbols]

[0114] 1 Wiring circuit board 2 Wiring section 3A 1st support part 3B 2nd support part 11 Metal support layer 12 Conductor layer 13 First insulating layer (an example of an insulating layer) 14 Circuit pattern (example of first circuit pattern) 141A terminal (example of first terminal) 143A wiring 30 Second circuit pattern 31 terminal (example of second terminal) S1 One side surface of the metal support layer T1 Thickness of metal support layer T2 Conductor layer thickness W1: Dimension of the metal support layer in the second direction W2: Dimension of the conductor layer in the second direction

Claims

1. a wiring portion having wiring extending in a first direction and extending in the first direction; a first support portion that supports one end of the wiring portion in the first direction; Equipped with The wiring portion is a metal support layer; a conductor layer disposed on one surface of the metal support layer in a thickness direction of the metal support layer; the wiring arranged on one side of the conductor layer in the thickness direction; an insulating layer disposed between the conductor layer and the wiring in the thickness direction; and A printed circuit board, wherein the ratio of the thickness of the metal support layer to the dimension of the metal support layer in a second direction perpendicular to both the thickness direction and the first direction is less than 1.

2. The printed circuit board according to claim 1 , wherein the metal support layer has a thickness of more than 30 μm.

3. The printed circuit board according to claim 1 , wherein the conductor layer has a thickness of 1 μm or more.

4. 2. The wired circuit board according to claim 1, wherein the ratio of the thickness of said conductor layer to the thickness of said metal support layer is 1 / 30 to 1 / 3.

5. The printed circuit board according to claim 1 , wherein a ratio of a dimension of said conductor layer in said second direction to a dimension of said metal support layer in said second direction is ½ or more.

6. The printed circuit board according to claim 1 , further comprising a second support portion that supports the other end of the wiring portion in the first direction.

7. a first circuit pattern having the wiring and a first terminal connected to the wiring; a second circuit pattern having a second terminal connected to the conductor layer and independent from the first circuit pattern; The wired circuit board according to claim 1 , comprising:

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