Wiring circuit board, and method for manufacturing a wiring circuit board

Abstract

To provide a wiring circuit board whose pedestal can be efficiently formed and a wiring circuit board manufacturing method.SOLUTION: A suspension substrate 1 fitted with a circuit includes a wiring region 2 and a loading region 3. The wiring region 2 has part of wires 143A, 143B, 143C, and 143D. The loading region 3 is continuous with the wiring region 2. A slider S is loaded in the loading region 3. The loading region has a pedestal 16A for supporting the slider S. The wiring region 2 has: a metal support layer 11; a first conductor layer 12 which is arranged on the metal support layer 11; a first insulating layer 13 which is arranged on the first conductor layer 12; and a second conductor layer 14 which is arranged on the first insulating layer 13. The second conductor layer 14 forms the wires 143A, 143B, 143C, and 143D. The pedestal 16A has the first conductor layer 12.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a wiring circuit board and a method for manufacturing the wiring circuit board.

Background Art

[0002] Conventionally, as a wiring circuit board, for example, a suspension substrate with a circuit mounted on a head gimbal assembly of a hard disk drive is known. The suspension substrate with a circuit can mount a slider having a magnetic head.

[0003] In such a suspension substrate with a circuit, it is known to provide a pedestal for supporting the slider at a slider mounting portion (see Patent Document 1 below).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the wiring circuit board as described in Patent Document 1 above, there is a desire to efficiently form the pedestal.

[0006] The present invention provides a wiring circuit board capable of efficiently forming a pedestal and a method for manufacturing the wiring circuit board.

Means for Solving the Problems

[0007] The present invention [1] includes a wiring circuit board comprising a wiring region having at least a portion of the wiring, and a mounting region continuous with the wiring region, on which electronic components are mounted, and having a base for supporting the electronic components, wherein the wiring region comprises a metal support layer, a first conductor layer disposed on the metal support layer, an insulating layer disposed on the first conductor layer, and a second conductor layer disposed on the insulating layer and forming the wiring, and the base having the first conductor layer.

[0008] In this configuration, the wiring region has a first conductor layer below the wiring.

[0009] Therefore, in the wiring area, it is possible to reduce the transmission loss of the wiring.

[0010] Furthermore, the base has a first conductor layer that constitutes the wiring area.

[0011] Therefore, the base can be efficiently formed by utilizing the process of forming the first conductor layer in the wiring area.

[0012] The present invention [2] includes the wiring circuit board of [1], wherein the base further comprises the insulating layer.

[0013] With this configuration, the thickness of the base can be efficiently adjusted by utilizing the process of forming an insulating layer in the wiring area.

[0014] The present invention [3] includes the wiring circuit board of [1] or [2] above, wherein the base further comprises the second conductor layer.

[0015] With this configuration, the thickness of the base can be efficiently adjusted by utilizing the process of forming a second conductor layer in the wiring area.

[0016] The present invention [4] is a method for manufacturing a wiring circuit board according to any one of the above [1] to [3], comprising the steps of: preparing the metal support layer; setting the wiring region and the mounting region on the metal support layer; forming the first conductor layer on the wiring region and forming the first conductor layer for forming the base on the mounting region; forming the insulating layer on at least the first conductor layer on the wiring region; and forming the second conductor layer on the insulating layer.

[0017] According to this method, in the process of forming a first conductor layer on a wiring area, a first conductor layer for forming a base is formed on a mounting area.

[0018] Therefore, the base can be efficiently formed by utilizing the process of forming the first conductor layer in the wiring area. [Effects of the Invention]

[0019] According to the wiring circuit board and the method for manufacturing the wiring circuit board of the present invention, it is possible to reduce the transmission loss of wiring in the wiring area and to efficiently form a base in the mounting area. [Brief explanation of the drawing]

[0020] [Figure 1] Figure 1 is a plan view of the suspension board with circuitry. [Figure 2] Figure 2A is a cross-sectional view AA of the circuit-equipped suspension board shown in Figure 1. Figure 2B is a cross-sectional view BB of the circuit-equipped suspension board shown in Figure 1. [Figure 3] Figures 3A and 3B are explanatory diagrams illustrating a method for manufacturing a circuit-equipped suspension substrate. Figure 3A shows the process of preparing a metal support layer and setting wiring areas and mounting areas on the metal support layer, while Figure 3B shows the process of forming a first conductor layer. [Figure 4]FIG. 4A and FIG. 4B are explanatory diagrams for explaining a method of manufacturing a suspended circuit board, following FIGS. 3A and 3B. FIG. 4A shows the step of forming a first insulating layer, and FIG. 4B shows the step of forming a second conductor layer. [Figure 5] FIG. 5A is an explanatory diagram for explaining a first modification. FIG. 5B is an explanatory diagram for explaining a second modification. FIG. 5C is an explanatory diagram for explaining a third modification. [Figure 6] FIG. 6A is an explanatory diagram for explaining a fourth modification. FIG. 6B is an explanatory diagram for explaining a fifth modification. FIG. 6C is an explanatory diagram for explaining a sixth modification.

BEST MODE FOR CARRYING OUT THE INVENTION

[0021] 1. Suspended Circuit Board Referring to FIGS. 1 and 2A, a suspended circuit board 1 as an example of a wiring circuit board will be described.

[0022] The suspended circuit board 1 is a component that constitutes a head gimbal assembly of a hard disk drive. The suspended circuit board 1 can mount a slider S (see FIG. 1) as an example of an electronic component. The slider S includes a magnetic head. 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. The suspended circuit board 1 supports the slider S and electrically connects the magnetic head to the control board of the hard disk drive.

[0023] As shown in FIG. 1, the suspended circuit board 1 has a wiring region 2 and a mounting region 3.

[0024] The wiring area 2 is an area electrically connected to the control board of the hard disk drive. The wiring area 2 includes parts of the wiring 143A, 143B, 143C, and 143D described later. The wiring area 2 extends in a first direction. The first direction is perpendicular to the thickness direction of the circuit-equipped suspension board 1. The wiring area 2 has a belt shape.

[0025] Mounting area 3 is the area that supports the slider S. Mounting area 3 is located at one end of the circuit-equipped suspension board 1. Mounting area 3 is continuous with one end of the wiring area 2. Mounting area 3 has a slider mounting section 3A and an outrigger section 3B.

[0026] A slider S is mounted on the slider mounting section 3A. In other words, a slider S is mounted on the mounting area 3. In this embodiment, the slider mounting section 3A has a substantially rectangular shape in plan view. However, the shape of the slider mounting section 3A is not limited.

[0027] The outrigger section 3B is arranged around the slider mounting section 3A so as to surround it. In this embodiment, the outrigger section 3B has a frame shape that is substantially rectangular in plan view. However, the shape of the outrigger section 3B is not limited. One end of the slider mounting section 3A is continuous with the inner periphery of the outrigger section 3B.

[0028] As shown in Figure 2A, the circuit-equipped suspension substrate 1 comprises a metal support layer 11, a first conductor layer 12, a first insulating layer 13 as an example of an insulating layer, a second conductor layer 14, and a second insulating layer 15.

[0029] (1) Metal support layer The metal support layer 11 supports the first conductor layer 12, the first insulating layer 13, the second conductor layer 14, and the second insulating layer 15. Examples of materials for the metal support layer 11 include stainless steel and copper alloys.

[0030] (2) First conductor layer The first conductor layer 12 is arranged on the metal support layer 11 in the thickness direction. The first conductor layer 12 is made of metal. Examples of metals include copper, silver, gold, iron, aluminum, chromium, and alloys thereof. From the viewpoint of obtaining good electrical properties, copper is preferred.

[0031] The circuit-equipped suspension substrate 1 may also include an adhesion layer between the metal support layer 11 and the first conductor layer 12. The adhesion layer improves the adhesion of the first conductor layer 12 to the metal support substrate 11. The adhesion layer is made of metal. Examples of metals include chromium, nickel, titanium, and alloys thereof.

[0032] (3) First insulating layer The first insulating layer 13 is positioned on the metal support layer 11 and the first conductor layer 12 in the thickness direction. The first insulating layer 13 insulates the second conductor layer 14 from the metal support layer 11 and the first conductor layer 12. The first insulating layer 13 is made of resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0033] The circuit-equipped suspension substrate 1 may also include a protective layer between the first conductor layer 12 and the first insulating layer 13. The protective layer protects the first conductor layer 12. The protective layer is made of metal. Examples of metals include chromium, nickel, titanium, and alloys thereof.

[0034] (3) Second conductor layer The second conductor layer 14 is arranged on the first insulating layer 13 in the thickness direction. The second conductor layer 14 is made of a metal. Examples of metals include copper, silver, gold, iron, aluminum, chromium, and alloys thereof. From the viewpoint of obtaining good electrical properties, copper is preferred.

[0035] The second conductor layer 14 forms a conductor pattern. As shown in Figure 1, the conductor pattern has multiple terminals 141A, 141B, 141C, 141D, multiple terminals 142A, 142B, 142C, 142D, and multiple wirings 143A, 143B, 143C, 143D. In other words, the second conductor layer 14 forms the wirings 143A, 143B, 143C, 143D. The shape of the conductor pattern is not limited.

[0036] (3-1) Terminals 141A, 141B, 141C, 141D Terminals 141A, 141B, 141C, and 141D are arranged on one side of the slider mounting section 3A in the first direction. Terminals 141A, 141B, 141C, and 141D are spaced apart from each other in the second direction. The second direction is perpendicular to the thickness direction and intersects with the first direction. When the slider S is mounted on the circuit-equipped suspension board 1, terminals 141A, 141B, 141C, and 141D are electrically connected to the magnetic head of the slider S. Each of terminals 141A, 141B, 141C, and 141D has a corner land shape.

[0037] (3-2) Terminals 142A, 142B, 142C, 142D Terminals 142A, 142B, 142C, and 142D are located at the other end of wiring area 2 in the first direction. Terminals 142A, 142B, 142C, and 142D are electrically connected to the control board of the hard disk drive.

[0038] (3-3) Wiring Wiring 143A electrically connects terminals 141A and 142A. One end of wiring 143A is connected to terminal 141A. The other end of wiring 143A is connected to terminal 142A.

[0039] Wiring 143B electrically connects terminals 141B and 142B. One end of wiring 143B is connected to terminal 141B. The other end of wiring 143B is connected to terminal 142B.

[0040] Wiring 143C electrically connects terminals 141C and 142C. One end of wiring 143C is connected to terminal 141C. The other end of wiring 143B is connected to terminal 142C.

[0041] Wiring 143D electrically connects terminals 141D and 142D. One end of wiring 143D is connected to terminal 141D. The other end of wiring 143D is connected to terminal 142D.

[0042] (4) Second insulating layer As shown in Figure 2A, the second insulating layer 15 covers the wiring 143A, 143B, 143C, and 143D. The second insulating layer 15 is positioned on top of the first insulating layer 13 in the thickness direction. The second insulating layer 15 does not cover the terminals 141A, 141B, 141C, 141D, and the terminals 142A, 142B, 142C, and 142D. The second insulating layer 15 is made of resin. Examples of resins include polyimide, maleimide, epoxy resin, polybenzoxazole, and polyester.

[0043] 2. Details of the wiring area Next, we will describe the details of wiring area 2 with reference to Figure 2A.

[0044] As shown in Figure 2A, the wiring region 2 has a metal support layer 11, a first conductor layer 12, a first insulating layer 13, and a second conductor layer 14, as described above.

[0045] In wiring region 2, the first conductor layer 12 is positioned below wiring 143A, 143B, 143C, and 143D. This reduces the transmission loss of wiring 143A, 143B, 143C, and 143D in wiring region 2. The first conductor layer 12 may also be positioned below terminals 142A, 142B, 142C, and 142D.

[0046] Furthermore, in wiring region 2, the first insulating layer 13 is positioned on top of the first conductor layer 12 in the thickness direction. The first insulating layer 13 is positioned between the first conductor layer 12 and the second conductor layer 14. The first insulating layer 13 insulates the second conductor layer 14 from the first conductor layer 12.

[0047] 3. Details of the mounting area Next, we will describe the details of mounting area 3 with reference to Figures 1 and 2B.

[0048] As shown in Figure 2B, in mounting region 3, the first conductor layer 12 is not located below the conductor pattern (wiring 143A, 143B, 143C, 143D, and terminals 141A, 141B, 141C, 141D).

[0049] In mounting region 3, the first insulating layer 13 is positioned between the metal support layer 11 and the second conductor layer 14. The first insulating layer 13 insulates the second conductor layer 14 from the metal support layer 11.

[0050] Furthermore, as shown in Figure 1, the mounting area 3 has multiple bases 16A, 16B, and 16C. The bases 16A, 16B, and 16C are arranged independently of the first conductor layer 12 of the wiring area 2. Specifically, the bases 16A, 16B, and 16C are arranged apart from each other in the mounting area 3 so as to form the vertices of a triangle. Each of the bases 16A, 16B, and 16C has a circular shape in plan view. When the slider S is mounted on the circuit-equipped suspension board, the bases 16A, 16B, and 16C support the slider S. The arrangement of the bases 16A, 16B, and 16C is not limited as long as the slider S can be stably supported.

[0051] As shown in Figure 2B, the base 16A has a first conductor layer 12, a first insulating layer 13, a second conductor layer 14, and a second insulating layer 15. In other words, the base 16A has the same layer structure as the wiring region 2 (see Figure 2A). Therefore, the base 16A can be efficiently formed using the manufacturing process of the circuit-equipped suspension substrate 1.

[0052] Bases 16B and 16C have the same structure as base 16A. Therefore, the explanation for bases 16B and 16C is omitted.

[0053] 4. Manufacturing method of a suspension board with circuitry Next, the manufacturing method of the circuit-equipped suspension substrate 1 will be described with reference to Figures 2A to 4B.

[0054] To manufacture the circuit-equipped suspension substrate 1, first, a metal support layer 11 is prepared as shown in Figure 3A. In this embodiment, the metal support layer 11 is a metal foil drawn from a roll of metal foil.

[0055] Next, the wiring area 2 and mounting area 3 described above are set in the metal support layer 11.

[0056] Next, as shown in Figure 3B, a first conductor layer 12 is formed on the wiring region 2, and a first conductor layer 12 for forming the bases 16A, 16B, and 16C is formed on the mounting region 3. The first conductor layer 12 is formed, for example, by electroplating.

[0057] In more detail, a plating resist is bonded onto the metal support layer 11, and the plating resist is exposed to light while the area where the first conductor layer 12 is to be formed is shielded from light.

[0058] Next, the exposed plating resist is developed. This removes the plating resist from the light-shielded areas, exposing the metal support layer 11 in the areas where the first conductor layer 12 will be formed. The plating resist remains in the exposed areas, i.e., the areas where the first conductor layer 12 will not be formed.

[0059] Next, a first conductive layer 12 is formed on the exposed metal support layer 11 by electroplating. After the electroplating is completed, the plating resist is peeled off.

[0060] Alternatively, before forming the first conductor layer 12 (before bonding the plating resist to the metal support layer 11), the above-described adhesion layer may be formed on the metal support layer 11, and the first conductor layer 12 may be formed on top of the adhesion layer.

[0061] Alternatively, the protective layer described above may be formed on the first conductor layer 12 after the first conductor layer 12 has been formed (after the plating resist has been removed).

[0062] Methods for forming an adhesion layer or protective layer include, for example, sputtering, electrolytic plating, and electroless plating.

[0063] Next, as shown in Figure 4A, a first insulating layer 13 is formed on the first conductor layer 12 of the wiring area 2 and the mounting area 3. More specifically, the first insulating layer 13 is formed on the first conductor layer 12 of the wiring area 2 and on the metal support layer 11 of the mounting area 3 (the part that will become the outrigger section 3B). If a protective layer is formed on the first conductor layer 12, the first insulating layer 13 is formed on the protective layer. At this time, in the mounting area 3, the first insulating layer 13 for forming the bases 16A, 16B, and 16C is formed on the first conductor layer 12 for forming the bases 16A, 16B, and 16C.

[0064] To form the first insulating layer 13, first, a photosensitive resin solution (varnish) is applied to the metal support layer 11 or the first conductor layer 12 and dried to form a photosensitive resin coating. Next, the photosensitive resin coating is exposed to light and developed. This forms the first insulating layer 13.

[0065] Next, as shown in Figure 4B, a second conductor layer 14 is formed on the first insulating layer 13. More specifically, a conductor pattern (second conductor layer 14) is formed on the first insulating layer 13 in the wiring area 2 and the mounting area 3 (the part that will become the outrigger section 3B). At this time, in the mounting area 3, a second conductor layer 14 for forming the bases 16A, 16B, and 16C is formed on the first insulating layer 13 for forming the bases 16A, 16B, and 16C. The second conductor layer 14 is formed, for example, by electroplating.

[0066] More specifically, a seed layer is formed on the surface of the first insulating layer 13. The seed layer is formed, for example, by sputtering. Examples of materials for the seed layer include chromium, copper, nickel, titanium, and alloys thereof.

[0067] Next, a plating resist is bonded onto the first insulating layer 13 on which the seed layer is formed, and the plating resist is exposed to light while the area where the second conductive layer 14 will be formed is shielded from light.

[0068] Next, the exposed plating resist is developed. This removes the plating resist from the light-shielded areas, exposing the seed layer in the areas where the second conductive layer 14 will be formed. The plating resist remains in the exposed areas, i.e., the areas where the second conductive layer 14 will not be formed.

[0069] Next, a second conductive layer 14 is formed on the exposed seed layer by electroplating. After the electroplating is complete, the plating resist is removed.

[0070] Next, the seed layer, which was covered by the plating resist, is removed by etching.

[0071] Next, a second insulating layer 15 (see Figures 2A and 2B) is formed on the first insulating layer 13 and the second conductor layer 14 in the same manner as the formation of the first insulating layer 13. Specifically, the second insulating layer 15 is formed on the first insulating layer 13 and the second conductor layer 14 in the wiring area 2 and the mounting area 3 (the part that will become the outrigger section 3B). At this time, in the mounting area 3, the second insulating layer 15 for forming the bases 16A, 16B, and 16C is formed on the second conductor layer 14 for forming the bases 16A, 16B, and 16C.

[0072] Next, the metal support layer 11 is etched to form the outer shape of the circuit-equipped suspension substrate 1. This completes the circuit-equipped suspension substrate 1.

[0073] 5. Effects (1) According to the circuit-equipped suspension board 1, as shown in Figure 2A, the wiring region 2 has a first conductor layer 12 below the wirings 143A, 143B, 143C, and 143D.

[0074] Therefore, in wiring area 2, the transmission loss of wiring 143A, 143B, 143C, and 143D can be reduced.

[0075] Furthermore, as shown in Figure 2B, the base 16A has a first conductor layer 12 that constitutes the wiring region 2 (see Figure 2A).

[0076] Therefore, the base 16A can be efficiently formed by utilizing the process of forming the first conductor layer 12 in the wiring region 2.

[0077] (2) According to the circuit-equipped suspension board 1, as shown in Figure 2B, the base 16A further has a first insulating layer 13.

[0078] Therefore, the thickness of the base 16A can be efficiently adjusted by utilizing the process of forming the first insulating layer 13 in the wiring area 2.

[0079] (3) According to the circuit-equipped suspension board 1, as shown in Figure 2B, the base 16A further has a second conductor layer 14.

[0080] Therefore, the thickness of the base 16A can be efficiently adjusted by utilizing the process of forming the second conductor layer 14 in the wiring region 2.

[0081] (4) According to the manufacturing method of the circuit-equipped suspension substrate 1, as shown in Figure 3B, in the step of forming the first conductor layer 12 on the wiring region 2, the first conductor layer 12 for forming the base 16A is formed on the mounting region 3.

[0082] Therefore, the base 16A can be efficiently formed by utilizing the process of forming the first conductor layer 12 in the wiring region 2.

[0083] 6. Variations Next, a modified example will 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.

[0084] (1) The base 16A may be placed in the mounting area 3 in the portion where the wiring of the conductor pattern is formed. In this case, as shown in Figure 5A, the second conductor layer 14 of the base 16A may be wiring 100A, 100B.

[0085] (2) As shown in Figure 5B, the base 16A may consist only of the first conductor layer 12.

[0086] (3) As shown in Figure 5C, the base 16A may be composed of a first conductor layer 12 and a first insulating layer 13.

[0087] (4) As shown in Figure 6A, the base 16A may be composed of a first conductor layer 12, a first insulating layer 13, and a second conductor layer 14.

[0088] (5) As shown in Figure 6B, the base 16A may be composed of a first conductor layer 12 and a second conductor layer 14.

[0089] (6) As shown in Figure 6C, the base 16A may be composed of a first conductor layer 12, a second conductor layer 14, and a second insulating layer 15.

[0090] (7) The electronic component is not limited to a slider. The wiring circuit board is not limited to a suspension board with circuits. The electronic component may be an integrated circuit such as a processor. The wiring circuit board may be a wiring circuit board on which a processor can be mounted. [Explanation of Symbols]

[0091] 1 Circuit-equipped suspension board 2 Wiring area 3 Loading area 11 Metal support layer 12. First Conductor Layer 13. First insulating layer 14. Second Conductor Layer 16A Base 143A Wiring S Slider

Claims

1. A wiring area having at least a portion of the wiring, The mounting area is continuous with the wiring area and includes a mounting area on which electronic components are mounted, and has a base for supporting the electronic components. The aforementioned wiring area is Metal support layer, A first conductor layer is disposed on the metal support layer so as to be in contact with the metal support layer, or is disposed on the metal support layer via an adhesive layer made of metal, An insulating layer disposed on the first conductor layer, It has a second conductor layer disposed on the insulating layer and forming the wiring, The base is a wiring circuit board having the first conductor layer.

2. The wiring circuit board according to claim 1, wherein the base further comprises the insulating layer.

3. The wiring circuit board according to claim 1 or claim 2, wherein the base further comprises the second conductor layer.

4. A method for manufacturing a wiring circuit board according to any one of claims 1 to 3, The steps include preparing the aforementioned metal support layer, The process of setting the wiring area and the mounting area in the metal support layer, The steps include forming the first conductor layer on the wiring region and forming the first conductor layer for forming the base on the mounting region, The steps include forming the insulating layer on the first conductor layer in at least the wiring region, A step of forming the second conductor layer on the insulating layer, A method for manufacturing a wiring circuit board, including the method described above.

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