Wiring circuit board

Abstract

The present invention provides a wiring circuit board that can suppress contact between a piezoelectric element and an insulating layer while the piezoelectric element is mounted on the wiring circuit board. [Solution] The circuit-equipped suspension substrate 1 comprises a metal support layer 21 having an opening 21A capable of receiving a piezoelectric element Pz1, a first insulating layer 22, a first terminal 12A exposed within the opening 21A and connectable to one end of the piezoelectric element Pz1, and a second terminal 13A exposed within the opening 21A and connectable to the other end of the piezoelectric element Pz1. The first insulating layer 22 has a first portion 224A located within the opening 21A and a second portion 225A located within the opening 21A and thinner than the first portion 224A. The second portion 225A is located between the first terminal 12A and the second terminal 13A and faces the piezoelectric element Pz1.

Description

Technical Field

[0001] The present invention relates to a wiring circuit board.

Background Art

[0002] Conventionally, as an example of a wiring circuit board, a circuit-mounted suspension board on which a slider including a magnetic head and a piezo element (piezoelectric element) can be mounted has been proposed (see, for example, Patent Document 1 below).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a circuit-mounted suspension board as described in Patent Document 1, when a piezo element is mounted on the circuit-mounted suspension board, there is a possibility that the piezo element contacts a part of the circuit-mounted suspension board (specifically, the base insulating layer) between the tip end portion and the rear end portion of the piezo element.

[0005] The present invention provides a wiring circuit board capable of suppressing contact between a piezoelectric element and an insulating layer in a state where the piezoelectric element is mounted on the wiring circuit board.

Means for Solving the Problems

[0006] The present invention [1] includes a wiring circuit board on which a piezoelectric element can be mounted, comprising: a metal support layer having an opening capable of receiving the piezoelectric element when the piezoelectric element is mounted on the wiring circuit board; an insulating layer; a first terminal supported by the insulating layer, exposed within the opening, and connectable to one end of the piezoelectric element; and a second terminal supported by the insulating layer, exposed within the opening, and connectable to the other end of the piezoelectric element, the second terminal being positioned away from the first terminal in a first direction perpendicular to the thickness direction of the insulating layer, wherein the insulating layer has a first portion positioned within the opening and a second portion positioned within the opening and thinner than the first portion, the second portion being positioned between the first terminal and the second terminal in the first direction and facing the piezoelectric element in the thickness direction when the piezoelectric element is mounted on the wiring circuit board.

[0007] With this configuration, a thin portion (second portion) of the first insulating layer is formed between the first terminal and the second terminal.

[0008] Therefore, when the piezoelectric element is mounted on a wiring circuit board, a gap can be secured between the piezoelectric element and the first insulating layer between the first terminal and the second terminal.

[0009] As a result, contact between the piezoelectric element and the first insulating layer can be suppressed while the piezoelectric element is mounted on the wiring circuit board.

[0010] The present invention [2] includes the wiring circuit board described in [1] above, wherein the insulating layer has a first through hole disposed within the opening and a second through hole disposed within the opening, the second through hole being located away from the first through hole in the first direction, the first terminal being exposed into the opening through the first through hole and the second terminal being exposed into the opening through the second through hole.

[0011] The present invention [3] includes the wiring circuit board of [1] or [2] described above, wherein the first portion is positioned between the inner circumferential edge of the opening and the second portion.

[0012] The present invention [4] includes, when the piezoelectric element is mounted on the wiring circuit board, one of the above [1] to [3] wiring circuit boards, which is opposed in the thickness direction to a portion of the piezoelectric element in a second direction perpendicular to both the thickness direction and the first direction.

[0013] The present invention [5] includes the wiring circuit board described in [4] above, wherein the wiring circuit board is capable of mounting the piezoelectric element and the second piezoelectric element, and when the piezoelectric element and the second piezoelectric element are mounted on the wiring circuit board, the second piezoelectric element is positioned away from the piezoelectric element in a second direction perpendicular to both the thickness direction and the first direction, the piezoelectric element has an outer end in the second direction and an inner end positioned between the outer end and the second piezoelectric element in the second direction, and the second portion does not face the inner end of the piezoelectric element but faces the outer end of the piezoelectric element.

[0014] With this configuration, contact between the outer end of the piezoelectric element and the first insulating layer can be suppressed between the first terminal and the second terminal.

[0015] The present invention [6] includes the wiring circuit board described in [4] above, wherein the wiring circuit board is capable of mounting the piezoelectric element and the second piezoelectric element, and when the piezoelectric element and the second piezoelectric element are mounted on the wiring circuit board, the second piezoelectric element is positioned away from the piezoelectric element in a second direction perpendicular to both the thickness direction and the first direction, the piezoelectric element has an outer end in the second direction and an inner end positioned between the outer end and the second piezoelectric element in the second direction, and the second portion does not face the outer end of the piezoelectric element but faces the inner end of the piezoelectric element.

[0016] With this configuration, contact between the inner end of the piezoelectric element and the first insulating layer can be suppressed between the first terminal and the second terminal.

[0017] According to the present invention [7], when the piezoelectric element is mounted on the wiring circuit board, the second portion includes all of the piezoelectric element in a second direction orthogonal to both the thickness direction and the first direction, and the wiring circuit board according to any one of [1] to [3] facing in the thickness direction.

[0018] According to such a configuration, contact between all of the piezoelectric element and the first insulating layer can be suppressed between the first terminal and the second terminal.

Advantages of the Invention

[0019] According to the wiring circuit board of the present invention, contact between the piezoelectric element and the insulating layer can be suppressed in a state where the piezoelectric element is mounted on the wiring circuit board.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a plan view (viewed from one side in the thickness direction) showing an embodiment of a circuit-mounted suspension board of the present invention. [Figure 2] FIG. 2 is a rear view (viewed from the other side in the thickness direction) of the circuit-mounted suspension board shown in FIG. 1. [Figure 3] FIGS. 3A and 3B are cross-sectional views taken along line A-A of the circuit-mounted suspension board shown in FIG. 1. FIG. 3B is a cross-sectional view taken along line B-B of the circuit-mounted suspension board shown in FIG. 2. [Figure 4] FIGS. 4A and 4B show a first insulating layer forming step in the manufacturing process of the circuit-mounted suspension board. [Figure 5] FIGS. 5A and 5B show a conductor layer forming step in the manufacturing process of the circuit-mounted suspension board. [Figure 6] FIGS. 6A and 6B show a second insulating layer forming step in the manufacturing process of the circuit-mounted suspension board. [Figure 7] FIGS. 7A and 7B show an opening forming step in the manufacturing process of the circuit-mounted suspension board. [Figure 8] FIGS. 8A and 8B show an etching step in the manufacturing process of the circuit-mounted suspension board. [Figure 9] FIG. 9A and FIG. 9B show an outer shape processing step in a manufacturing process of a suspension substrate with a circuit. [Figure 10] FIG. 10 is a plan view of a modified example (1) of a suspension substrate with a circuit. [Figure 11] FIG. 11 is a plan view of a modified example (2) of a suspension substrate with a circuit.

MODE FOR CARRYING OUT THE INVENTION

[0021] 1. Suspension Substrate with Circuit As shown in FIG. 1, a suspension substrate with a circuit 1 as an example of a wiring circuit board is a component that constitutes a head gimbal assembly of a hard disk drive. The suspension substrate with a circuit 1 can mount a slider (not shown) having a magnetic head, a piezoelectric element Pz1 (see FIG. 2), and a piezoelectric element Pz2 (see FIG. 2). The magnetic head can read data from the recording surface of the hard disk and write data to the recording surface of the hard disk. In the present embodiment, when the slider is mounted on the suspension substrate with a circuit 1, the slider is disposed on one side in the thickness direction (see FIG. 3A) with respect to the suspension substrate with a circuit 1. When the piezoelectric element Pz1 and the piezoelectric element Pz2 are mounted on the suspension substrate with a circuit 1, the piezoelectric element Pz1 and the piezoelectric element Pz2 are disposed on the other side in the thickness direction with respect to the suspension substrate with a circuit 1. That is, in a state where the slider, the piezoelectric element Pz1, and the piezoelectric element Pz2 are mounted on the suspension substrate with a circuit 1, the piezoelectric element Pz1 and the piezoelectric element Pz2 are disposed on the side opposite to the slider with respect to the suspension substrate with a circuit 1.

[0022] The suspension substrate with a circuit 1 has a mounting portion 1A, a wiring portion 1B, and an outrigger portion 1C.

[0023] (1) Mounting Portion The mounting section 1A is located at the tip of the circuit-equipped suspension board 1. The slider, piezoelectric element Pz1, and piezoelectric element Pz2 are mounted on the mounting section 1A. The mounting section 1A is supported at the tip of the wiring section 1B by the outrigger section 1C. The mounting section 1A extends in a first direction and a second direction. The first direction is the direction in which the first terminal 12A and the second terminal 13A, described later, are aligned. In other words, the first direction is the direction in which the piezoelectric element Pz1 expands and contracts. The second direction is the direction in which the magnetic head connection terminals 11A, 11B, 11C, and 11D, described later, are aligned. The second direction is perpendicular to the first direction. The first and second directions are perpendicular to the thickness direction of the first insulating layer 22 (see Figure 3A), described later.

[0024] As shown in Figure 2, when piezoelectric elements Pz1 and Pz2 are mounted on the mounting section 1A, piezoelectric element Pz2 is positioned away from piezoelectric element Pz1 in the second direction. When piezoelectric elements Pz1 and Pz2 are mounted on the mounting section 1A, piezoelectric element Pz2 is positioned on the other side of piezoelectric element Pz1 in the second direction.

[0025] As shown in Figure 1, the mounting section 1A includes a plurality of magnetic head connection terminals 11A, 11B, 11C, 11D, a first terminal 12A, a second terminal 13A, a third terminal 12B, a fourth terminal 13B, and a portion of each of the plurality of wirings 14A, 14B, 14C, 14D, 15A, 15B. In other words, the suspension board with circuitry 1 includes a first terminal 12A, a second terminal 13A, a third terminal 12B, and a fourth terminal 13B.

[0026] The magnetic head connection terminals 11A, 11B, 11C, and 11D are aligned in the second direction. With the slider mounted on the mounting section 1A, the magnetic head connection terminals 11A, 11B, 11C, and 11D are connected to the magnetic head.

[0027] The first terminal 12A is located in the center of the mounting section 1A in the first direction. In the first direction, the first terminal 12A is located between the magnetic head connection terminals 11A, 11B, 11C, 11D and the second terminal 13A. In the second direction, the first terminal 12A is located at one end of the mounting section 1A. When the piezoelectric element Pz1 is mounted on the mounting section 1A, the first terminal 12A is connected to one end of the piezoelectric element Pz1. The first terminal 12A has a substantially rectangular shape.

[0028] The second terminal 13A is positioned away from the first terminal 12A in the first direction. The second terminal 13A is positioned on the other side of the first terminal 12A in the first direction. The second terminal 13A is positioned at the other end of the mounting portion 1A in the first direction. The second terminal 13A is positioned at one end of the mounting portion 1A in the second direction. When the piezoelectric element Pz1 is mounted on the mounting portion 1A, the second terminal 13A is connected to the other end of the piezoelectric element Pz1. The second terminal 13A has a substantially rectangular shape.

[0029] The third terminal 12B is located in the center of the mounting section 1A in the first direction. In the first direction, the third terminal 12B is located between the magnetic head connection terminals 11A, 11B, 11C, 11D and the fourth terminal 13B. In the second direction, the third terminal 12B is located away from the first terminal 12A. In the second direction, the third terminal 12B is located on the other side of the first terminal 12A. In the second direction, the third terminal 12B is located at the other end of the mounting section 1A. When the piezoelectric element Pz2 is mounted on the mounting section 1A, the third terminal 12B is connected to one end of the piezoelectric element Pz2. The third terminal 12B has a substantially rectangular shape.

[0030] The fourth terminal 13B is positioned away from the third terminal 12B in the first direction. The fourth terminal 13B is positioned on the other side of the third terminal 12B in the first direction. The fourth terminal 13B is positioned at the other end of the mounting section 1A in the first direction. The fourth terminal 13B is positioned away from the second terminal 13A in the second direction. The fourth terminal 13B is positioned on the other side of the second terminal 13A in the second direction. The fourth terminal 13B is positioned at the other end of the mounting section 1A in the second direction. When the piezoelectric element Pz1 is mounted on the mounting section 1A, the fourth terminal 13B is connected to the other end of the piezoelectric element Pz2. The fourth terminal 13B has a substantially rectangular shape.

[0031] (2) Wiring section The wiring section 1B is located on the other side of the mounting section 1A in a first direction. The wiring section 1B is located away from the mounting section 1A. The wiring section 1B extends in a first direction. The wiring section 1B has a belt shape. The wiring section 1B has wiring 14A, 14B, 14C, 14D and wiring 15A, 15B, a plurality of external connection terminals 101A, 101B, 101C, 101D and a plurality of external connection terminals 102A, 102B.

[0032] Wiring 14A electrically connects the magnetic head connection terminal 11A and the external connection terminal 101A, which will be described later. One end of wiring 14A is connected to the magnetic head connection terminal 11A. The other end of wiring 14A is connected to the external connection terminal 101A.

[0033] Wiring 14B electrically connects the magnetic head connection terminal 11B and the external connection terminal 101B, which will be described later. One end of wiring 14B is connected to the magnetic head connection terminal 11B. The other end of wiring 14B is connected to the external connection terminal 101B.

[0034] Wiring 14C electrically connects the magnetic head connection terminal 11C and the external connection terminal 101C, which will be described later. One end of wiring 14C is connected to the magnetic head connection terminal 11C. The other end of wiring 14C is connected to the external connection terminal 101C.

[0035] Wiring 14D electrically connects the magnetic head connection terminal 11D and the external connection terminal 101D, which will be described later. One end of wiring 14D is connected to the magnetic head connection terminal 11D. The other end of wiring 14D is connected to the external connection terminal 101D.

[0036] Wiring 15A electrically connects the second terminal 13A and the external connection terminal 102A, which will be described later. One end of wiring 15A is connected to the second terminal 13A. The other end of wiring 15A is connected to the external connection terminal 102A.

[0037] Wiring 15B electrically connects the fourth terminal 13B and the external connection terminal 102B, which will be described later. One end of wiring 15B is connected to the fourth terminal 13B. The other end of wiring 15B is connected to the external connection terminal 102B.

[0038] External connection terminals 101A, 101B, 101C, 101D, and external connection terminals 102A, 102B are arranged in a predetermined direction with a distance between them. The direction in which external connection terminals 101A, 101B, 101C, 101D, and external connection terminals 102A, 102B are arranged may be different from the second direction.

[0039] (3) Outrigger section The outrigger section 1C is positioned around the mounting section 1A. The outrigger section 1C has a substantially frame shape. The outrigger section 1C is made of the same material as the metal support layer 21, which will be described later. As shown in Figure 2, the outrigger section 1C is continuous with the metal support layer 21 of the mounting section 1A and the metal support layer 21 of the wiring section 1B.

[0040] 2. Layer configuration of the circuit-equipped suspension board Next, the layer configuration of the circuit-equipped suspension substrate 1 will be described.

[0041] As shown in Figure 3A, the circuit-equipped suspension substrate 1 comprises a metal support layer 21, a first insulating layer 22 as an example of an insulating layer, a conductor layer 23, and a second insulating layer 24.

[0042] The conductor layer 23 includes magnetic head connection terminals 11A, 11B, 11C, 11D, first terminal 12A, second terminal 13A, third terminal 12B, fourth terminal 13B, multiple wirings 14A, 14B, 14C, 14D, 15A, 15B, and external connection terminals 101A, 101B, 101C, 101D, 102A, 102B.

[0043] (1) Metal support layer The metal support layer 21 supports the first insulating layer 22, the conductor layer 23, and the second insulating layer 24. Examples of materials for the metal support layer 21 include stainless steel and copper alloys.

[0044] As shown in Figure 2, the metal support layer 21 of the mounting section 1A has two openings 21A and 21B.

[0045] When the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the opening 21A is capable of receiving the piezoelectric element Pz1.

[0046] The opening 21B is positioned away from the opening 21A in the second direction. When the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the opening 21B is capable of receiving the piezoelectric element Pz2.

[0047] (2) First insulating layer As shown in Figure 3A, the first insulating layer 22 is positioned on one side surface of the metal support layer 21 in the thickness direction. The first insulating layer 22 is positioned between the metal support layer 21 and the conductor layer 23. The first insulating layer 22 insulates the metal support layer 21 from the conductor layer 23. The first insulating layer 22 is made of a resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester. The first insulating layer 22 is preferably made of polyimide.

[0048] As shown in Figure 2, the first insulating layer 22 of the mounting portion 1A has a first through hole 221A, a second through hole 222A, a third through hole 221B, a fourth through hole 222B, and two through holes 223A and 223B (see Figure 1).

[0049] The first through-hole 221A and the second through-hole 222A are located within the opening 21A. The second through-hole 222A is located away from the first through-hole 221A in the first direction. The second through-hole 222A is located on the other side of the first through-hole 221A in the first direction.

[0050] The third through-hole 221B and the fourth through-hole 222B are located within the opening 21B. The fourth through-hole 222B is located away from the third through-hole 221B in the first direction. The fourth through-hole 222B is located on the other side of the third through-hole 221B in the first direction.

[0051] As shown in Figure 1, the through hole 223A is located near the first through hole 221A. The through hole 223A is not located within the opening 21A (see Figure 2). In the thickness direction, the through hole 223A overlaps with the metal support layer 21.

[0052] The through hole 223B is located near the third through hole 221B. The through hole 223B is not located within the opening 21B (see Figure 2). In the thickness direction, the through hole 223B overlaps with the metal support layer 21.

[0053] (3) Conductor layer As shown in Figure 3A, the conductor layer 23 is arranged on one side surface of the first insulating layer 22 in the thickness direction. The conductor layer 23 is made of a metal. Examples of metals include copper, silver, gold, iron, aluminum, and alloys thereof. The conductor layer 23 is preferably made of copper. The conductor layer 23 is supported by the first insulating layer 22. In other words, the first terminal 12A, the second terminal 13A, the third terminal 12B, and the fourth terminal 13B are supported by the first insulating layer 22.

[0054] The first terminal 12A contacts the metal support layer 21 through the through hole 223A. This electrically connects the first terminal 12A to the metal support layer 21. The first terminal 12A is exposed into the opening 21A through the first through hole 221A. As a result, when the piezoelectric element Pz1 is mounted on the mounting section 1A, the first terminal 12A is connected to one end of the piezoelectric element Pz1 via the bonding agent B.

[0055] The second terminal 13A is exposed into the opening 21A through the second through-hole 222A. As a result, when the piezoelectric element Pz1 is mounted on the mounting section 1A, the second terminal 13A is connected to the other end of the piezoelectric element Pz1 via the bonding agent B.

[0056] As shown in Figure 1, the third terminal 12B contacts the metal support layer 21 (see Figure 2) through the through hole 223B. This electrically connects the third terminal 12B to the metal support layer 21. As shown in Figure 2, the third terminal 12B is exposed into the opening 21B through the third through hole 221B. This connects the third terminal 12B to one end of the piezoelectric element Pz2 when the piezoelectric element Pz2 is mounted on the mounting section 1A.

[0057] The fourth terminal 13B is exposed into the opening 21B through the fourth through-hole 222B. As a result, when the piezoelectric element Pz2 is mounted on the mounting section 1A, the fourth terminal 13B is connected to the other end of the piezoelectric element Pz2.

[0058] (4) Second insulating layer As shown in Figure 3A, the second insulating layer 24 is arranged on one side surface of the first insulating layer 22 in the thickness direction. The second insulating layer 24 covers the wiring 14A, 14B, 14C, 14D, 15A, 15B, the first terminal 12A, the second terminal 13A, the third terminal 12B, and the fourth terminal 13B. The second insulating layer 24 does not cover the magnetic head connection terminals 11A, 11B, 11C, and 11D. The second insulating layer 24 is made of resin. The same resin as the first insulating layer 22 described above can be used as the resin. Preferably, the second insulating layer 24 is made of polyimide.

[0059] 3. Details of the first insulating layer As shown in Figure 2, the first insulating layer 22 has a first portion 224A, a second portion 225A, a third portion 224B, and a fourth portion 225B.

[0060] (1) Part 1 The first portion 224A is positioned within the opening 21A. The first portion 224A is positioned within the opening 21A around the second portion 225A. The first portion 224A is positioned between the inner circumferential edge of the opening 21A and the second portion 225A.

[0061] (2)Second part The second portion 225A is positioned within the opening 21A. In the first direction, the second portion 225A is positioned between the first terminal 12A and the second terminal 13A. The second portion 225A is thinner than the first portion 224A. More specifically, in the thickness direction, the other surface of the second portion 225A is positioned one side (towards the conductor layer 23) than the other surface of the first portion 224A. In other words, in the thickness direction, the second portion 225A is recessed one side (towards the conductor layer 23) than the first portion 224A. When the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the second portion 225A faces the piezoelectric element Pz1 in the thickness direction. This suppresses contact between the piezoelectric element Pz1 and the first insulating layer 22 between the first terminal 12A and the second terminal 13A.

[0062] As shown in Figures 2 and 3B, in this embodiment, when the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the second portion 225A faces a part of the piezoelectric element Pz1 in the second direction in the thickness direction.

[0063] More specifically, the second part 225A has an outer end E1 and an inner end E2 in the second direction. The inner end E2 is positioned between the outer end E1 and the opening 21B in the second direction. When the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the inner end E2 is positioned between the outer end E1 and the piezoelectric element Pz2 in the second direction. The piezoelectric element Pz1 has an outer end E11 and an inner end E12 in the second direction. When the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the inner end E12 is positioned between the outer end E11 and the opening 21B in the second direction. When the piezoelectric elements Pz1 and Pz2 are mounted on the circuit-equipped suspension substrate 1, the inner end E12 is positioned between the outer end E11 and the piezoelectric element Pz2 in the second direction.

[0064] In this embodiment, when the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the inner end E2 of the second portion 225A is positioned between the outer end E11 and the inner end E12 of the piezoelectric element Pz1 in the second direction. Therefore, when the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the second portion 225A does not face the inner end E12 of the piezoelectric element Pz1.

[0065] On the other hand, when the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the outer end E1 of the second portion 225A is positioned on one side (outside) of the outer end E11 of the piezoelectric element Pz1 in the second direction. Therefore, when the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the outer end E11 of the piezoelectric element Pz1 is positioned between the outer end E1 of the second portion 225A and the inner end E2 of the second portion 225A in the second direction. In other words, when the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the second portion 225A faces the outer end E11 of the piezoelectric element Pz1. This makes it possible to suppress contact between the outer end E11 of the piezoelectric element Pz1 and the first insulating layer 22 between the first terminal 12A and the second terminal 13A.

[0066] (3) Third part The third portion 224B is positioned within the opening 21B. Within the opening 21B, the third portion 224B is positioned around the fourth portion 225B. The third portion 224B is positioned between the inner circumferential edge of the opening 21B and the fourth portion 225B.

[0067] (4) Fourth part The fourth portion 225B is positioned within the opening 21B. In the first direction, the fourth portion 225B is positioned between the third terminal 12B and the fourth terminal 13B. The fourth portion 225B is thinner than the third portion 224B. More specifically, in the thickness direction, the other surface of the fourth portion 225B is positioned to one side of the other surface of the third portion 224B. In other words, in the thickness direction, the fourth portion 225B is recessed to one side compared to the third portion 224B. When the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the fourth portion 225B faces the piezoelectric element Pz2 in the thickness direction. This suppresses contact between the piezoelectric element Pz2 and the first insulating layer 22 between the third terminal 12B and the fourth terminal 13B.

[0068] As shown in Figure 2, in this embodiment, when the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the fourth portion 225B faces a part of the piezoelectric element Pz1 in the second direction in the thickness direction.

[0069] More specifically, the fourth portion 225B has an outer end E21 and an inner end E22 in the second direction. The inner end E22 is positioned between the outer end E21 and the opening 21A in the second direction. When the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the inner end E22 is positioned between the outer end E21 and the piezoelectric element Pz1 in the second direction. The piezoelectric element Pz2 has an outer end E31 and an inner end E32 in the second direction. When the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the inner end E32 is positioned between the outer end E31 and the opening 21A in the second direction. When the piezoelectric elements Pz1 and Pz2 are mounted on the circuit-equipped suspension substrate 1, the inner end E32 is positioned between the outer end E31 and the piezoelectric element Pz1 in the second direction.

[0070] In this embodiment, when the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the inner end E22 of the fourth portion 225B is positioned between the outer end E31 and the inner end E32 of the piezoelectric element Pz2 in the second direction. Therefore, when the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the fourth portion 225B does not face the inner end E32 of the piezoelectric element Pz2.

[0071] On the other hand, when the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the outer end E21 of the fourth portion 225B is positioned on the other side (outside) of the outer end E31 of the piezoelectric element Pz2 in the second direction. Therefore, when the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the outer end E31 of the piezoelectric element Pz2 is positioned between the outer end E21 of the fourth portion 225B and the inner end E22 of the fourth portion 225B in the second direction. In other words, when the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the fourth portion 225B faces the outer end E31 of the piezoelectric element Pz2. This prevents the outer end E31 of the piezoelectric element Pz2 from coming into contact with the first insulating layer 22 between the third terminal 12B and the fourth terminal 13B.

[0072] 4. Manufacturing method of a suspension board with circuitry Next, a method for manufacturing the circuit-equipped suspension substrate 1 will be described.

[0073] The manufacturing method for the circuit-equipped suspension substrate 1 includes a first insulating layer formation step (see Figures 4A and 4B), a conductor layer formation step (see Figures 5A and 5B), a second insulating layer formation step (see Figures 6A and 6B), an opening formation step (see Figures 7A and 7B), an etching step (see Figures 8A and 8B), and an outer shape processing step (see Figures 9A and 9B).

[0074] (1) First insulating layer formation process As shown in Figures 4A and 4B, in the first insulating layer formation step, the first insulating layer 22 is formed on a metal substrate M. The metal substrate M is the material for the metal support layer 21 and the outrigger portion 1C.

[0075] In the first insulating layer formation step, a first insulating layer 22 having a first recess 220A, a second recess 220B, a third recess 220C (not shown), a fourth recess 220D (not shown), and through holes 223A, 223B is formed by gradation exposure. The first recess 220A is formed in the area where the first terminal 12A is formed, the second recess 220B is formed in the area where the second terminal 13A is formed, the third recess 220C is formed in the area where the third terminal 12B is formed, and the fourth recess 220D is formed in the area where the fourth terminal 13B is formed.

[0076] In more detail, first, a photosensitive resin solution (varnish) is applied to the substrate M and dried to form a photosensitive resin coating.

[0077] Next, the photosensitive resin coating is subjected to gradation exposure using a photomask having light-shielding portions, fully transparent portions, and semi-transparent portions. The light-shielding portions face the portions of the photosensitive resin coating where the first insulating layer 22 is not formed and where through holes 223A and 223B are formed. The semi-transparent portions face the portions of the photosensitive resin coating where the first recess 220A, second recess 220B, third recess 220C, and fourth recess 220D are formed. The fully transparent portions face the remaining portions of the photosensitive resin coating.

[0078] Next, the exposed coating is developed. The portion of the coating facing the semi-transparent portion is developed to be thinner than the portion facing the fully transparent portion. As the coating is developed, a first insulating layer 22 is formed having a first recess 220A, a second recess 220B, a third recess 220C, a fourth recess 220D, and through holes 223A, 223B.

[0079] (2) Conductor layer formation process Next, as shown in Figures 5A and 5B, in the conductor layer formation process, the conductor layer 23 is formed on the first insulating layer 22.

[0080] More specifically, in the conductor layer formation process, a seed layer is first formed in the thickness direction on one side surface of the first insulating layer 22 and on one side surface of the substrate M. The seed layer is formed, for example, by sputtering. Examples of materials for the seed layer include chromium, copper, nickel, titanium, and alloys thereof.

[0081] Next, a plating resist is applied to one side surface of the substrate M in the thickness direction. The plating resist covers the first insulating layer 22.

[0082] Next, the plating resist is exposed and developed. This removes the plating resist in the areas where the conductive layer 23 will be formed, exposing the seed layer in those areas. On the other hand, the plating resist remains in the areas where the conductive layer will not be formed.

[0083] Next, a conductive layer 23 is formed on the exposed seed layer by electroplating. After the electroplating is completed, the plating resist is peeled off. Then, the seed layer exposed by the peeling off of the plating resist is removed by etching.

[0084] (3) Second insulating layer formation process Next, as shown in Figures 6A and 6B, in the second insulating layer formation step, the second insulating layer 24 is formed on the first insulating layer 22.

[0085] The second insulating layer 24 is formed in the same manner as the first insulating layer 22. More specifically, in the second insulating layer formation step, first, a photosensitive resin solution (varnish) is applied to the conductor layer 23, the first insulating layer 22, and the substrate M, and dried to form a photosensitive resin coating.

[0086] Next, the photosensitive resin coating is exposed to light and developed. This forms a second insulating layer 24 on top of the first insulating layer 22.

[0087] (4) Opening formation process Next, as shown in Figures 7A and 7B, in the opening formation step, the substrate M is etched to form openings 21A and 21B. As a result of the opening formation step, the first insulating layer 22 is exposed within openings 21A and 21B.

[0088] (5) Etching process Next, as shown in Figures 8A and 8B, the first insulating layer 22 in the opening 21A and the first insulating layer 22 in the opening 21B are etched. This exposes the first terminal 12A and the second terminal 13A in the opening 21A and forms the second portion 225A. In addition, the third terminal 12B and the fourth terminal 13B are exposed in the opening 21B and form the fourth portion 225B.

[0089] (6) External shape processing process Next, as shown in Figures 9A and 9B, the substrate M is etched to form the metal support layer 21 and the outrigger portion 1C (see Figure 2).

[0090] Thus, a suspension board with circuitry 1 is obtained.

[0091] 5. Effects (1) In the circuit-equipped suspension board 1, as shown in Figures 2 and 3B, a portion of the first insulating layer 22 (second portion 225A) is formed thinly between the first terminal 12A and the second terminal 13A.

[0092] Therefore, when the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, a gap can be secured between the piezoelectric element Pz1 and the first insulating layer 22 between the first terminal 12A and the second terminal 13A.

[0093] As a result, contact between the piezoelectric element Pz1 and the first insulating layer 22 can be suppressed while the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1.

[0094] (2) With the circuit-equipped suspension board 1, as shown in Figures 2 and 3B, the second portion 225A does not face the inner end E12 of the piezoelectric element Pz1, but faces the outer end E11 of the piezoelectric element Pz1.

[0095] Therefore, a gap can be secured between the outer end E11 of the piezoelectric element Pz1 and the first insulating layer 22 between the first terminal 12A and the second terminal 13A.

[0096] As a result, contact between the outer end E11 of the piezoelectric element Pz1 and the first insulating layer 22 can be suppressed between the first terminal 12A and the second terminal 13A.

[0097] 6. Variations A modified example will now be described. In the modified example, the same reference numerals are used for components similar to those in the above-described embodiment, and their descriptions are omitted.

[0098] (1) As shown in Figure 10, the second portion 225A may not face the outer end E11 of the piezoelectric element Pz1, but may face the inner end E12 of the piezoelectric element Pz1.

[0099] In this modified example, when the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the outer end E1 of the second portion 225A is positioned in the second direction between the outer end E11 of the piezoelectric element Pz1 and the inner end E12 of the piezoelectric element Pz1.

[0100] Furthermore, when the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the inner end E2 of the second portion 225A is positioned on the other side (inward) of the inner end E12 of the piezoelectric element Pz1 in the second direction. When the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the inner end E12 of the piezoelectric element Pz1 is positioned between the outer end E1 of the second portion 225A and the inner end E2 of the second portion 225A in the second direction.

[0101] Furthermore, the fourth portion 225B may not face the outer end E31 of the piezoelectric element Pz2, but rather face the inner end E32 of the piezoelectric element Pz2.

[0102] When the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the outer end E21 of the fourth portion 225B is positioned in the second direction between the outer end E31 of the piezoelectric element Pz2 and the inner end E32 of the piezoelectric element Pz2.

[0103] Furthermore, when the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the inner end E22 of the fourth portion 225B is positioned to one side (inward) of the inner end E32 of the piezoelectric element Pz2 in the second direction. When the piezoelectric element Pz2 is mounted on the circuit-equipped suspension substrate 1, the inner end E32 of the piezoelectric element Pz2 is positioned between the outer end E21 of the fourth portion 225B and the inner end E22 of the fourth portion 225B in the second direction.

[0104] This modified example also provides the same effects and benefits as the embodiment described above.

[0105] Furthermore, in this modified example, a gap can be secured between the inner end E12 of the piezoelectric element Pz1 and the first insulating layer 22 between the first terminal 12A and the second terminal 13A.

[0106] As a result, contact between the inner end E12 of the piezoelectric element Pz2 and the first insulating layer 22 can be suppressed between the first terminal 12A and the second terminal 13A.

[0107] (2) As shown in Figure 11, when the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the second portion 225A may face the entire piezoelectric element Pz1 in the second direction in the thickness direction.

[0108] In this modified example, when the piezoelectric element Pz1 is mounted on the circuit-equipped suspension substrate 1, the outer end E1 of the second portion 225A is positioned on one side (outer) than the outer end E11 of the piezoelectric element Pz1 in the second direction, and the inner end E2 of the second portion 225A is positioned on the other side (inner) than the inner end E12 of the piezoelectric element Pz1 in the second direction.

[0109] This modified example also provides the same effects and benefits as the embodiment described above.

[0110] Furthermore, in this modified example, a gap can be secured between the entire piezoelectric element Pz1 in the second direction and the first insulating layer 22 between the first terminal 12A and the second terminal 13A.

[0111] As a result, contact between the piezoelectric element Pz2 and the first insulating layer 22 between the first terminal 12A and the second terminal 13A can be more reliably suppressed. [Explanation of Symbols]

[0112] 1 Circuit-equipped suspension board 12A Terminal 1 13A 2nd terminal 21 Metal support layer 21A opening 22 First insulating layer 221A First through hole 222A 2nd through hole 224A Part 1 225A 2nd part Pz1 Piezoelectric element E11 Outer end of piezoelectric element E12 Inner end of piezoelectric element Pz2 Piezoelectric element (second piezoelectric element)

Claims

1. A wiring circuit board capable of mounting piezoelectric elements, A metal support layer having an opening capable of receiving the piezoelectric element when the piezoelectric element is mounted on the wiring circuit board, Insulating layer and, A first terminal is supported by the insulating layer, exposed within the opening, and connectable to one end of the piezoelectric element, A second terminal supported by the insulating layer, exposed within the opening, and connectable to the other end of the piezoelectric element, wherein the second terminal is positioned away from the first terminal in a first direction perpendicular to the thickness direction of the insulating layer. Equipped with, The insulating layer is A first portion disposed within the opening, It has a second portion that is positioned within the opening and is thinner than the first portion, The second portion is a wiring circuit board, which is positioned between the first terminal and the second terminal in the first direction and faces the piezoelectric element in the thickness direction when the piezoelectric element is mounted on the wiring circuit board.

2. The insulating layer is A first through hole is disposed within the opening, A second through-hole disposed within the opening, wherein the second through-hole is disposed away from the first through-hole in the first direction. It has, The first terminal is exposed into the opening through the first through hole, The wiring circuit board according to claim 1, wherein the second terminal is exposed in the opening through the second through hole.

3. The wiring circuit board according to claim 1, wherein the first portion is disposed between the inner circumferential edge of the opening and the second portion.

4. The wiring circuit board according to claim 1, wherein when the piezoelectric element is mounted on the wiring circuit board, the second portion faces a part of the piezoelectric element in the second direction which is orthogonal to both the thickness direction and the first direction, in the thickness direction.

5. The aforementioned wiring circuit board can be equipped with the piezoelectric element and the second piezoelectric element. When the piezoelectric element and the second piezoelectric element are mounted on the wiring circuit board, The second piezoelectric element is positioned away from the piezoelectric element in a second direction perpendicular to both the thickness direction and the first direction. The piezoelectric element has an outer end in the second direction and an inner end positioned between the outer end and the second piezoelectric element in the second direction. The wiring circuit board according to claim 4, wherein the second portion does not face the inner end of the piezoelectric element, but faces the outer end of the piezoelectric element.

6. The aforementioned wiring circuit board can be equipped with the piezoelectric element and the second piezoelectric element. When the piezoelectric element and the second piezoelectric element are mounted on the wiring circuit board, The second piezoelectric element is positioned away from the piezoelectric element in a second direction perpendicular to both the thickness direction and the first direction. The piezoelectric element has an outer end in the second direction and an inner end positioned between the outer end and the second piezoelectric element in the second direction. The wiring circuit board according to claim 4, wherein the second portion does not face the outer end of the piezoelectric element, but faces the inner end of the piezoelectric element.

7. The wiring circuit board according to claim 1, wherein when the piezoelectric elements are mounted on the wiring circuit board, the second portion faces all of the piezoelectric elements in the second direction which is orthogonal to both the thickness direction and the first direction, in the thickness direction.

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