JP7252767B2 - Method for manufacturing suspension board with circuit, and suspension board assembly with circuit - Google Patents

Description

The present invention relates to a method for manufacturing a suspension board with circuit and a suspension board assembly with circuit.

2. Description of the Related Art Conventionally, a suspension board with circuit mounted with a slider having a magnetic head and mounted on a hard disk drive has been known.

For example, a metal supporting substrate, a base insulating layer arranged on one side of the metal supporting substrate, a conductor pattern arranged on one side of the base insulating layer, and a conductor pattern arranged on one side of the base insulating layer and covering the conductive pattern A suspension board with circuit has been proposed that includes an insulating cover layer that supports a slider, and a support layer that is disposed on one side of the insulating cover layer and supports a slider (see, for example, Patent Document 1).

In order to manufacture such a suspension board with circuit, first, a varnish containing a photosensitive resin is coated on a metal supporting board, and then exposed and developed to form an insulating base layer. After that, a conductive pattern is formed on the base insulating layer by an additive method or a subtractive method, and then a varnish containing a photosensitive resin is applied on the base insulating layer and the conductive pattern, and then exposed and developed to cover. forming an insulating layer; Next, a varnish containing a photosensitive resin is applied onto the insulating cover layer, and then exposed and developed to form a support layer.

JP 2016-152051 A

However, in the production of the suspension board with circuit described in Patent Document 1, there are cases where the insulating layers (the insulating base layer, the insulating cover layer, and the support layer) are poorly formed due to errors such as failure to perform exposure. .

Therefore, in manufacturing the suspension board with circuit, it is desired to improve the quality of the suspension board with circuit by inspecting the formation defect of the insulating layer.

The present invention provides a method of manufacturing a suspension board with circuit and a suspension board assembly with circuit, which can inspect formation defects of the first insulating layer and/or the second insulating layer.

The present invention [1] comprises the steps of preparing a metal supporting layer, forming a first insulating layer on one side of the metal supporting layer in the thickness direction, and forming a conductive pattern on one side of the first insulating layer in the thickness direction. forming a second insulating layer on one side in the thickness direction of the first insulating layer; and inspecting a formation defect of the first insulating layer and/or the second insulating layer; In the step of forming the first insulating layer and/or the step of forming the second insulating layer, the metal support layer is formed by the same step as the step of forming the first insulating layer and/or the second insulating layer forming an inspection insulating layer at a position different from the first insulating layer on one side in the thickness direction, and in the step of inspecting, bringing a probe into contact with the inspection insulating layer to inspect continuity with the metal support layer , a method of manufacturing a suspension board with circuit.

According to this method, the test insulating layer is formed in the same step as the formation of the first insulating layer and/or the second insulating layer. While both the insulating layer and/or the second insulating layer and the test insulating layer are formed, if an error occurs in the process of forming the insulating layers, the first insulating layer and/or the second insulating layer and the test insulating layer are formed. malformation occurs in both

Therefore, in the inspection process, if the probe contacts the inspection insulating layer and the conduction with the metal support layer is blocked, it can be confirmed that the first insulating layer and/or the second insulating layer are formed normally. If the probe contacts and conducts with the metal support layer without contacting the test insulating layer, it can be confirmed that the first insulating layer and/or the second insulating layer are malformed.

As a result, it is possible to inspect for formation defects of the first insulating layer and/or the second insulating layer using a simple method.

In the present invention [2], the step of forming the second insulating layer includes forming a first insulating cover layer on one surface in the thickness direction of the first insulating layer so as to cover the conductor pattern; and forming a second insulating cover layer on one side in the thickness direction of the first insulating cover layer, wherein the step of forming the second insulating cover layer is performed on the one side in the thickness direction of the first insulating cover layer. a step of collectively applying a varnish containing a photosensitive resin to the surface and a position different from the first insulating layer on the one surface in the thickness direction of the metal support layer; and exposing and developing the applied varnish. and forming the second insulating cover layer and the inspection insulating layer at the same time.

According to this method, the varnish containing the photosensitive resin is collectively applied to one surface of the first insulating cover layer in the thickness direction and to a position different from that of the first insulating layer on one surface of the metal support layer in the thickness direction. After application, the applied varnish is exposed and developed to simultaneously form a second cover insulating layer and a test insulating layer.

Therefore, if the steps of forming the second cover insulating layer and the inspection insulating layer are performed normally, both the second cover insulating layer and the inspection insulating layer can be reliably formed, while the second cover insulating layer and the inspection insulating layer If an error occurs in the process of forming the , for example, exposure is not performed, both the second cover insulating layer and the inspection insulating layer are not formed.

As a result, it is possible to improve the inspection accuracy for defective formation of the second insulating cover layer.

In particular, since the second insulating cover layer does not affect the conduction of the conductor pattern, it is difficult to confirm the formation defect of the second insulating cover layer in the conduction test of the conductor pattern. On the other hand, according to the method described above, it is possible to smoothly inspect for defective formation of the second insulating cover layer.

The present invention [3] is a suspension board assembly with circuit comprising a plurality of suspension boards with circuit, comprising a plurality of suspension parts corresponding to the plurality of suspension boards with circuit, and a plurality of suspension boards with circuit. A metal support layer including a support portion for collective support, a first insulating layer arranged on one side in the thickness direction of the suspension portion, and a conductor pattern arranged on one side in the thickness direction of the first insulating layer. , forming a second insulating layer arranged on one side in the thickness direction of the first insulating layer, and forming the first insulating layer and/or the second insulating layer arranged on one side in the thickness direction of the supporting portion; and an inspection insulating layer for inspecting for defects.

According to such a configuration, the suspension board with circuit assembly includes the inspection insulating layer arranged on one side in the thickness direction of the support portion, so that the inspection step in the method for manufacturing the suspension board with circuit described above can be smoothly carried out. It is possible to inspect the formation defects of the first insulating layer and/or the second insulating layer.

In addition, since the inspection insulating layer is arranged in a support portion different from the suspension portion corresponding to the suspension board with circuit, the probe is placed on the inspection insulating layer as compared with the case where the inspection insulating layer is arranged in the suspension portion. can be brought into contact with the Therefore, the inspection insulating layer can be smoothly used for inspection of formation defects of the first insulating layer and/or the second insulating layer.

In the present invention [4], the second insulating layer comprises a first insulating cover layer arranged on one side in the thickness direction of the first insulating layer so as to cover the conductor pattern, and the first insulating cover layer. and a second insulating cover layer arranged on one side in the thickness direction of the layer, wherein the thickness of the inspection insulating layer is equal to or greater than the thickness of the second insulating cover layer. A suspension board assembly is included.

According to such a configuration, since the thickness of the inspection insulation layer is equal to or greater than the thickness of the second cover insulation layer, the probe is brought into contact with the inspection insulation layer from the thickness direction to inspect the continuity with the metal support layer. Sometimes it is possible to make a stable contact between the test insulating layer and the probe. Therefore, it is possible to further improve the inspection accuracy for defective formation of the second insulating cover layer.

In the present invention [5], the dimension of the inspection insulating layer in a first direction orthogonal to the thickness direction is 30 μm or more and 500 μm or less, and the dimension in a second direction orthogonal to both the thickness direction and the first direction is The suspension board with circuit assembly according to the above [4] or [5], wherein the inspection insulating layer has a dimension of 30 μm or more and 500 μm or less.

According to this configuration, since the dimension of the inspection insulating layer in the first direction is within the above range and the dimension of the inspection insulating layer in the second direction is within the above range, the probe is brought into contact with the inspection insulating layer. When testing continuity with the metal support layer, the test insulating layer and probes can be brought into contact with each other more stably.

According to the method for manufacturing a suspension board with circuit of the present invention, it is possible to inspect for defective formation of the first insulating layer and/or the second insulating layer, although it is a simple method.

The suspension-board-with-circuit assembly of the present invention can smoothly perform the inspection step in the above-described suspension-board-with-circuit manufacturing method, and the inspection insulating layer is used to detect defects in the first insulating layer and/or the second insulating layer. can be used smoothly for the inspection of

FIG. 1 shows a plan view of an assembly sheet as one embodiment of the suspension board assembly with circuit of the present invention. FIG. 2 shows an enlarged view of the suspension board with circuit shown in FIG. FIG. 3 shows a cross-sectional view of the suspension board with circuit shown in FIG. 2 along the line AA. FIG. 4 shows an enlarged view of the inspection part shown in FIG. FIG. 5 shows a BB cross-sectional view of the inspection section shown in FIG. FIG. 6A shows the step of preparing a metal support layer. FIG. 6B shows the step of forming a base insulating layer and an inspection base layer on the metal support layer following FIG. 6A. FIG. 6C shows a step of forming a conductor pattern on the insulating base layer and forming an inspection conductor layer on the inspection base layer, following FIG. 6B. FIG. 6D shows a step of forming a first insulating cover layer on the insulating base layer and forming an inspection cover layer on the inspection base layer, following FIG. 6C. FIG. 7A shows the step of forming a cover film following FIG. 6D. FIG. 7B shows a step of exposing the cover film through a photomask following FIG. 7A. FIG. 7C shows the step of developing the cover coating to form a second cover insulating layer and a test insulating layer following FIG. 7B. FIG. 8 shows a first modification of the inspection section shown in FIG. 5 (a form in which the inspection insulating layer and the base insulating layer are formed in the same process). FIG. 9 shows a second modification of the inspection portion shown in FIG. 5 (a form in which the inspection insulation layer is formed in the same process as the first cover insulation layer). FIG. 10 shows a third modification (mode in which a plurality of inspection insulating layers are provided) of the inspection section shown in FIG. FIG. 11 shows a first modified example (an embodiment including a conductor pattern and a second conductor pattern) of the suspension board with circuit shown in FIG. FIG. 12 shows a fourth modified example of the inspection section shown in FIG.

<First embodiment>
1. Assembly Sheet Hereinafter, an assembly sheet 1 as a first embodiment of a suspension assembly with circuit according to the present invention will be described with reference to FIGS. 1 to 5. FIG.

As shown in FIG. 1 , the assembly sheet 1 includes a plurality of suspension groups 2 , a support section 3 as an example of a support section, and a plurality of inspection sections 4 . In FIG. 1, the number of the plurality of suspension groups 2 is four and the number of the plurality of inspection units 4 is four for the sake of convenience. not.

The plurality of suspension groups 2 are separated from each other by a grid-like frame 6, which will be described later. Each suspension group 2 is composed of a plurality of suspension boards with circuit 5 extending in a predetermined direction, and in each suspension group 2, the plurality of suspension boards with circuit 5 are spaced apart from each other in an alignment direction orthogonal to the predetermined direction. ing. That is, the assembly sheet 1 includes a plurality of suspension boards with circuit 5 .

More specifically, the assembly sheet 1 has a plurality (two) of rows of a plurality (two) of suspension groups 2 arranged in a row direction orthogonal to the longitudinal direction (predetermined direction) of the suspension board with circuit 5 in the longitudinal direction. Prepare.

Although FIG. 1 shows three suspension boards with circuit 5 in each suspension group 2 for convenience, the number of suspension boards with circuit 5 provided in each suspension group 2 is not particularly limited.

In FIG. 1, the vertical direction of the paper is the longitudinal direction (first direction) of the suspension board with circuit 5, the upper side of the paper is one longitudinal direction side (first direction one side), and the lower side of the paper is the other longitudinal direction side (first direction). one direction and the other side).

In FIG. 1, the horizontal direction of the paper is the alignment direction (second direction) in which the plurality of suspension boards with circuit 5 are aligned. side (the other side in the second direction).

In FIG. 1, the paper thickness direction is the thickness direction of the aggregate sheet 1 (the third direction orthogonal to the first direction and the second direction), and the front side of the paper is one side in the thickness direction (one side in the third direction). , is the other side in the thickness direction (the other side in the third direction). Specifically, it conforms to the directional arrows in each figure.

In the following description, the longitudinal direction of the suspension board with circuit 5 is simply referred to as the longitudinal direction, the alignment direction of the plurality of suspension boards with circuit 5 is simply the alignment direction, and the thickness direction of the assembly sheet 1 is simply the thickness direction.

The supporting portion 3 is continuous with a metal support 8 (described later) of the plurality of suspension boards with circuit 5 and collectively supports the plurality of suspension boards with circuit 5 . The support portion 3 includes a frame 6 and a plurality of connection portions 7 . The frame 6 has a lattice shape, and one suspension group 2 is arranged in each of the plurality of openings 6A defined by the frame 6 . Thereby, the frame 6 surrounds the suspension groups 2 one by one, and separates the plurality of suspension groups 2 . The connecting portion 7 connects the metal support 8 and the frame 6, which will be described later.

A plurality of inspection units 4 are provided on a frame 6 of the support unit 3 . In this embodiment, the inspection units 4 correspond to the suspension group 2 and are provided in the same number as the suspension group 2 .

2. Suspension Board with Circuit Next, details of the suspension board with circuit 5 will be described with reference to FIGS. 2 and 3. FIG.

As shown in FIG. 2, each suspension board with circuit 5 has a flat belt shape extending in the longitudinal direction, and the middle portion (for example, the central portion) in the longitudinal direction is bent in the alignment direction.

As shown in FIG. 3, such a suspension board with circuit 5 includes a metal support 8 as an example of a suspension portion, an insulating base layer 9 as an example of a first insulating layer, a conductor pattern 10, and a second insulating layer. An insulating cover layer 11 as an example of an insulating layer is provided in order from the other side in the thickness direction toward the one side. Note that the insulating base layer 9 and the insulating cover layer 11 are omitted in FIG. 1 for the sake of convenience.

As shown in FIG. 1, the metal support 8 has the same outer shape as the suspension board with circuit 5 described above, extends in the longitudinal direction, and has a middle portion (for example, central portion) in the longitudinal direction. is bent into The metal support 8 has openings 16 . The opening 16 is arranged at one longitudinal end of the metal support 8 . The opening 16 has a concave shape that opens toward one side in the longitudinal direction. The opening 16 penetrates the metal support 8 in the thickness direction.

Such a metal support 8 is integrated with the support portion 3 described above, and the support portion 3 and the metal support 8 are positioned on the same plane. The support portion 3 and the metal support 8 constitute a metal support layer 12 . That is, the metal support layer 12 includes a plurality of metal supports 8 corresponding to the plurality of suspension boards with circuit 5 and the support portion 3 .

Examples of the material of the metal support layer 12 include metal materials such as stainless steel, 42 alloy, aluminum, copper-beryllium, and phosphor bronze, preferably stainless steel. The thickness of the metal support layer 12 is, for example, 10 μm or more, preferably 15 μm or more, and for example, 35 μm or less, preferably 25 μm or less.

As shown in FIG. 3, the insulating base layer 9 is arranged on one surface of the metal support 8 in the thickness direction. Although not shown, the insulating base layer 9 is provided as a predetermined pattern corresponding to the conductor pattern 10 to be described later, and is arranged between the metal support 8 and the conductor pattern 10 in the thickness direction.

Examples of materials for the base insulating layer 9 include synthetic resins such as polyimide resin, polyamideimide resin, acrylic resin, polyether resin, nitrile resin, polyethersulfone resin, polyethylene terephthalate resin, polyethylene naphthalate resin, and polyvinyl chloride resin. and preferably a polyimide resin. The thickness of the insulating base layer 9 is, for example, 1 μm or more, preferably 3 μm or more, and for example, 25 μm or less, preferably 15 μm or less.

The conductive pattern 10 is arranged on one side of the insulating base layer 9 in the thickness direction. As shown in FIG. 2 , the conductor pattern 10 includes multiple (four) magnetic head terminals 13 , multiple (four) external connection terminals 14 , and multiple (four) wirings 15 .

The plurality (four) of magnetic head terminals 13 are electrically connected to the magnetic head of the slider 100 when the slider 100 is mounted on the suspension board with circuit 5 (see FIG. 3). The plurality of magnetic head terminals 13 are arranged at one longitudinal end of the suspension board with circuit 5 . The plurality of magnetic head terminals 13 are arranged on one side in the thickness direction of the insulating base layer 9 so as to be surrounded by the opening 16 when viewed from the one side in the thickness direction.

A plurality of (four) external connection terminals 14 are arranged on one surface of the insulating base layer 9 in the thickness direction at the other longitudinal end of the suspension board with circuit 5 .

A plurality of (four) wirings 15 are routed on the insulating base layer 9 to electrically connect the plurality of magnetic head terminals 13 and the plurality of external connection terminals 14 .

Examples of the material of the conductive pattern 10 include conductive materials such as copper, nickel, gold, solder, or alloys thereof, preferably copper. The thickness of the conductive pattern 10 is, for example, 1 μm or more, preferably 3 μm or more, and for example, 20 μm or less, preferably 12 μm or less.

As shown in FIG. 3 , the insulating cover layer 11 is arranged on one side of the insulating base layer 9 in the thickness direction. The insulating cover layer 11 includes a first insulating cover layer 18 and a second insulating cover layer 19 .

The first insulating cover layer 18 is arranged on one side in the thickness direction of the insulating base layer 9 so as to cover the conductive pattern 10 . Specifically, as shown in FIG. 2, the first insulating cover layer 18 has a pattern shape that exposes the magnetic head terminals 13 and the external connection terminals 14 and covers the wiring 15 when viewed from one side in the thickness direction. ing.

Examples of the material of the first insulating cover layer 18 include the same synthetic resin as the insulating base layer 9, preferably polyimide resin. The thickness of the first insulating cover layer 18 is, for example, 2 μm or more, preferably 4 μm or more, and for example, 20 μm or less, preferably 15 μm or less.

As shown in FIG. 3 , the second insulating cover layer 19 is arranged on one surface of the first insulating cover layer 18 in the thickness direction. The second insulating cover layer 19 includes a pair of pedestals 20 that support the slider 100 when the slider 100 is mounted on the suspension board with circuit 5 .

The pair of pedestals 20 is arranged on one side in the longitudinal direction of the plurality of magnetic head terminals 13 . The pair of pedestals 20 are arranged with a space therebetween in the longitudinal direction. Each of the pedestals 20 has a rectangular shape in a plan view extending in the row direction (see FIG. 2).

Examples of the material of the second insulating cover layer 19 include the same synthetic resin as the insulating base layer 9, preferably polyimide resin. The thickness of the second insulating cover layer 19 is, for example, 1 μm or more, preferably 2 μm or more, and for example, 10 μm or less, preferably 8 μm or less.

3. Support Section Next, the details of the support section 3 will be described with reference to FIG.

The support portion 3 includes the frame 6 and the plurality of connection portions 7 as described above.

The frame body 6 has a lattice shape and integrally includes a plurality (three) of vertical frames 22 and a plurality (three) of horizontal frames 23 .

The plurality of vertical frames 22 are arranged at intervals so as to sandwich each suspension group 2 in the alignment direction. Each vertical frame 22 has a substantially rectangular shape in a plan view extending in the longitudinal direction.

The plurality of horizontal frames 23 are arranged at intervals so as to sandwich each suspension group 2 in the longitudinal direction. The plurality of horizontal frames 23 are connected to the plurality of vertical frames 22 so as to form a grid pattern with the plurality of vertical frames 22 . Each horizontal frame 23 has a substantially rectangular shape in plan view extending in the row direction.

The plurality of connecting portions 7 correspond to the plurality of suspension boards with circuit 5 . More specifically, as shown in FIG. 2, the connecting portions 7 are provided on both sides of each suspension board with circuit 5 in the longitudinal direction.

The connection portion 7 positioned on one longitudinal side of the suspension board with circuit 5 is formed by connecting one longitudinal end of the metal support 8 and a lateral frame positioned on one longitudinal side of the suspension board with circuit 5 . 23 and located on the other side in the longitudinal direction with respect to the suspension board with circuit 5 , the other end in the longitudinal direction of the metal support 8 and It connects with the horizontal frame 23 located on the other side.

4. Inspection Unit Next, details of the inspection unit 4 will be described with reference to FIGS. 2, 4 and 5. FIG.

As shown in FIG. 2 , the inspection section 4 is arranged on the horizontal frame 23 of the support section 3 . In the present embodiment, one inspection unit 4 corresponds to each suspension group 2, and is arranged so as to overlap the suspension board with circuit 5 positioned at one end in the alignment direction of each suspension group 2 when viewed from the longitudinal direction. (See FIG. 1).

As shown in FIGS. 4 and 5, the inspection section 4 includes an inspection base layer 25, an inspection conductor layer 26, an inspection cover layer 27, and an inspection insulation layer .

The inspection base layer 25 is arranged on one surface of the horizontal frame 23 in the thickness direction. The inspection base layer 25 is located on the same plane as the base insulating layer 9 (see FIG. 3). The inspection base layer 25 has a planar rectangular shape extending in the alignment direction when viewed from the thickness direction.

The inspection base layer 25 has a first opening 25A and a second opening 25B.

The first opening 25A is arranged on one side of the inspection base layer 25 in the alignment direction. The first opening 25A penetrates the inspection base layer 25 in the thickness direction and exposes one surface of the horizontal frame 23 in the thickness direction. The first opening 25A has a rectangular shape in plan view.

The second opening 25B is spaced apart from the first opening 25A on the other side in the alignment direction. The second opening 25B penetrates the inspection base layer 25 in the thickness direction and exposes one side of the horizontal frame 23 in the thickness direction. The second opening 25B has a circular shape in plan view.

The material of the inspection base layer 25 is the same as the material of the base insulating layer 9 . The thickness of the inspection base layer 25 is the same as the thickness of the insulating base layer 9 .

The inspection conductor layer 26 includes inspection terminals 29 and via portions 30 .

The inspection terminals 29 are arranged on one surface of the inspection base layer 25 in the thickness direction. The inspection terminal 29 is located on the side opposite to the first opening 25A with respect to the second opening 25B.

The inspection terminal 29 has a substantially rectangular shape in plan view. The longitudinal dimension of the inspection terminal 29 is, for example, 15 μm or more, preferably 30 μm or more, and for example, 1000 μm or less, preferably 500 μm or less. The dimension of the inspection terminals 29 in the alignment direction is, for example, 15 μm or more, preferably 30 μm or more, and for example, 1000 μm or less, preferably 500 μm or less.

The via portion 30 is positioned on one side of the inspection terminals 29 in the alignment direction and is continuous with the inspection terminals 29 . The via portion 30 is electrically connected to the horizontal frame 23 through the second opening 25B. The central portion of the via portion 30 is depressed to fill the second opening 25B and is in contact with the lateral frame 23 . A peripheral portion of the via portion 30 is arranged on one surface of the inspection base layer 25 in the thickness direction.

The material of the inspection conductor layer 26 is the same as the material of the conductor pattern 10 . The thickness of the inspection conductor layer 26 is the same as the thickness of the conductor pattern 10 .

The inspection cover layer 27 is arranged on one side in the thickness direction of the inspection base layer 25 so as to cover the via portion 30 . The inspection cover layer 27 has a communication port 27A and a terminal exposure port 27B.

The communication port 27A penetrates the inspection cover layer 27 in the thickness direction and communicates with the first opening 25A. The communication port 27A has the same shape as the first opening 25A when viewed in the thickness direction.

The terminal exposure opening 27B is positioned on the other side in the alignment direction with a space therebetween with respect to the communication opening 27A. The terminal exposure opening 27B penetrates the inspection cover layer 27 in the thickness direction and exposes the inspection terminal 29 .

The material of the inspection cover layer 27 is the same as the material of the first insulating cover layer 18 . The thickness of the inspection cover layer 27 is the same as the thickness of the first insulating cover layer 18 .

In this embodiment, the inspection insulating layer 28 is used to inspect formation defects of the second insulating cover layer 19 (see FIG. 3).

The inspection insulating layer 28 is arranged on one side in the thickness direction of the horizontal frame 23 in the first opening 25A. The inspection insulating layer 28 has a rectangular shape in plan view.

The longitudinal dimension of the inspection insulating layer 28 is, for example, 15 μm or more, preferably 30 μm or more, and for example, 1000 μm or less, preferably 500 μm or less.

In addition, the longitudinal dimension of the inspection insulating layer 28 is, for example, 1 time or more, preferably 2 times or more, for example, 30 times or less, and preferably, the outer shape of the first insulation layer inspection probe 42 described later. 20 times or less.

The dimension in the alignment direction of the inspection insulating layer 28 is, for example, 15 μm or more, preferably 30 μm or more, and for example, 1000 μm or less, preferably 500 μm or less.

In addition, the dimension in the alignment direction of the inspection insulating layer 28 is, for example, 1 time or more, preferably 2 times or more, for example 30 times or less, and preferably, the outer shape of the first insulation layer inspection probe 42 described later. 20 times or less.

The material of the inspection insulation layer 28 is the same as the material of the second cover insulation layer 19 . The thickness of the inspection insulating layer 28 is, for example, the thickness of the second insulating cover layer 19 or more, preferably 1.1 times or more the thickness of the second insulating cover layer 19, for example, the thickness of the second insulating cover layer 19. is less than 5 times the thickness of the

Specifically, the thickness of the inspection insulating layer 28 is, for example, 2 μm or more, preferably 4 μm or more, more preferably 5 μm or more, for example, 30 μm or less, preferably 20 μm or less.

5. Method for Manufacturing Suspension Board with Circuit Next, a method for manufacturing the suspension board with circuit 5 as an embodiment of the method for manufacturing the suspension board with circuit of the present invention will be described with reference to FIGS. 6A to 7C.

The manufacturing method of the suspension board with circuit 5 includes a manufacturing process of the assembly sheet 1 and an inspection process of inspecting the formation defect of the second insulating cover layer 19 .

(5-1) Assembly Sheet Manufacturing Process The assembly sheet 1 manufacturing process is performed by, for example, a roll-to-roll method. In the manufacturing method of the assembly sheet 1, first, as shown in FIG. 6A, the metal support layer 12 is prepared. The metal support layer 12 has an elongated flat belt shape.

Next, as shown in FIG. 6B, an inspection base layer 25 is formed on one side in the thickness direction of the metal support layer 12 (FIG. 6B-2) by the same process as the formation of the insulating base layer 9 (see FIG. 6B-1). reference).

Specifically, a varnish containing a photosensitive resin (for example, polyimide) is applied to the entire one surface of the metal support layer 12 in the thickness direction and dried to form a base film. After that, the base film is exposed and developed, and heat-hardened if necessary to simultaneously form the insulating base layer 9 and the inspection base layer 25 .

A method of forming the insulating base layer 9 and the inspection base layer 25, a method of forming the first insulating cover layer 18 and the inspection cover layer 27, which will be described later, and a method of forming the second insulating cover layer 19 and the inspection insulating layer 28, which will be described later. are similar to each other. Therefore, the method of forming the second insulating cover layer 19 and the inspection insulating layer 28, which will be described later, will be illustrated and explained in detail, and the method of forming the other insulating layers will be omitted.

Next, as shown in FIG. 6C, for example, by an additive method or a subtractive method, a conductive pattern 10 is formed on one side in the thickness direction of the base insulating layer 9 (see FIG. 6C-1), and an inspection base layer 25 is formed. An inspection conductor layer 26 is formed on one side in the thickness direction (see FIG. 6C-2).

Next, as shown in FIG. 6D, a first insulating cover layer 18 is formed on one side in the thickness direction of the insulating base layer 9 so as to cover the wiring 15 in the same manner as the insulating base layer 9 and the inspection base layer 25 described above. is formed (see FIG. 6D-1), and an inspection cover layer 27 is formed on one surface in the thickness direction of the inspection base layer 25 so as to cover the via portion 30 (see FIG. 6D-2).

Next, as shown in FIGS. 7A to 7C, the second insulating cover layer 19 is formed on one surface of the first insulating cover layer 18 in the thickness direction, and the horizontal frame 23 exposed from the first opening 25A is also covered in the thickness direction. A test insulating layer 28 is formed on the surface.

Specifically, as shown in FIG. 7A, a varnish containing a photosensitive resin (for example, polyimide) is applied to the base insulating layer 9, the conductor pattern 10, the first cover insulating layer 18, the inspection base layer 25, A cover film 32 is formed by coating and drying so as to cover the inspection conductor layer 26 and the inspection cover layer 27 collectively.

In other words, the varnish containing the photosensitive resin is collectively applied to one surface in the thickness direction of the first insulating cover layer 18 and one surface in the thickness direction of the metal support layer 12 exposed from the first openings 25A.

A surface 32</b>A (one side in the thickness direction) of the cover film 32 is a flat surface parallel to the metal support layer 12 .

After that, as shown in FIG. 7B, a photomask 33 is arranged to face the surface 32A of the cover film 32, and the cover film 32 is exposed through the photomask 33. Then, as shown in FIG.

The photomask 33 has a first light-transmitting portion 33A (see FIG. 7B-1) corresponding to the pattern (a pair of pedestal portions 20) of the second insulating cover layer 19 and a second light-transmitting portion 33A corresponding to the inspection insulating layer . It includes a portion 33B (see FIG. 7B-2) and a light shielding portion 33C.

The thickness of the portion of the cover film 32 facing the first light transmitting portion 33A (hereinafter referred to as the first portion 32B) is the distance from one surface of the first insulating cover layer 18 in the thickness direction to the surface 32A. 2 It is shorter than the thickness of the portion of the cover film 32 facing the light transmitting portion 33B (hereinafter referred to as the second portion 32C) (the distance from one side in the thickness direction of the metal support layer 12 to the surface 32A).

Therefore, in the case of exposure, when ultraviolet rays capable of sufficiently insolubilizing the entire thickness direction of the first portion 32B of the cover film 32 are irradiated, the thickness of the insolubilized portion in the second portion 32C of the cover film 32 is equal to the thickness of the first portion 32B. thickness or more.

Next, as shown in FIG. 7C, the cover film 32 is developed with a known developing solution (eg, γ-butyrolactone) to dissolve and remove the unexposed portions and insufficiently exposed portions of the cover film 32 .

After that, the second insulating cover layer 19 and the inspection insulating layer 28 are formed in the same step by heating and curing as necessary.

Then, as shown in FIGS. 3 and 5, the metal support layer 12 is contoured to form the support 3 and the plurality of metal supports 8 by known processing methods.

As described above, the assembly sheet 1 is manufactured.

(5-2) Inspection Step Next, in the present embodiment, formation defects of the second insulating cover layer 19 are inspected.

More specifically, as shown in FIG. 1, an inspection jig 40 is used to inspect disconnection and/or short-circuiting of the wiring 15 of the plurality of suspension boards with circuit 5 in each suspension group 2, and to inspect the second cover insulation. Inspect layer 19 for malformations.

As shown in FIGS. 3 and 5, the inspection jig 40 includes a plurality of first conductor inspection probes 41, a plurality of second conductor inspection probes (not shown), and a first insulation layer inspection probe as an example of probes. 42 and a second insulating layer inspection probe 43 .

As shown in FIG. 3 , the plurality of first conductor inspection probes 41 can contact the plurality of magnetic head terminals 13 . In FIG. 3, one first conductor inspection probe 41 is in contact with one magnetic head terminal 13 for convenience, but the number of first conductor inspection probes 41 in contact with each magnetic head terminal 13 is There are no particular restrictions, and the number may be two or more. Each first conductor inspection probe 41 has a needle shape extending in the thickness direction. Although not shown, the first conductor inspection probe 41 is electrically connected to a first voltage detection circuit capable of detecting voltage.

A plurality of second conductor inspection probes (not shown) can contact the plurality of external connection terminals 14 . The number of second conductor inspection probes in contact with each external connection terminal 14 is, for example, the same as the number of first conductor inspection probes 41 in contact with each magnetic head terminal 13 . Although not shown, the second conductor inspection probe is electrically connected to a voltage application device capable of applying voltage.

As shown in FIG. 5, a first insulating layer inspection probe 42 is capable of contacting the test insulating layer 28 . In FIG. 5, one first insulating layer inspection probe 42 is in contact with each inspection insulating layer 28 for convenience, but the number of first insulating layer inspection probes 42 in contact with each inspection insulating layer 28 is particularly limited. may be two or more.

The first insulating layer inspection probe 42 has a needle shape extending in the thickness direction. The outer diameter of the first insulating layer inspection probe 42 is, for example, 30 μm or more and 100 μm or less. Although not shown, the first insulating layer inspection probe 42 is electrically connected to a second voltage detection circuit capable of detecting voltage.

The second insulating layer inspection probe 43 can contact the inspection terminal 29 . The number of the second insulating layer inspection probes 43 in contact with the inspection terminals 29 is, for example, the same as the number of the first insulating layer inspection probes 42 in contact with the inspection insulating layer 28 .

The second insulating layer inspection probe 43 has a needle shape extending in the thickness direction. The outer diameter range of the second insulating layer inspection probe 43 is the same as the outer diameter range of the first insulating layer inspection probe 42 . Although not shown, the second insulating layer inspection probe 43 is electrically connected to a voltage applying device capable of applying voltage.

In the inspection process, first, as shown in FIG. 1, the inspection jig 40 is opposed to one suspension group 2 from one side in the thickness direction.

Then, as shown in FIG. 3, the first conductor inspection probe 41 is brought into contact with the corresponding magnetic head terminal 13 and the second conductor inspection probe (not shown) is brought into contact with the corresponding external connection terminal 14 .

Also, as shown in FIG. 5, the first insulating layer inspection probe 42 is brought into contact with the inspection insulating layer 28 and the second insulating layer inspection probe 43 is brought into contact with the inspection terminal 29 .

However, in the process of forming the second insulating cover layer 19 and the inspection insulating layer 28 described above (see FIGS. 7A to 7C), if an error occurs, for example, exposure is not performed, the second insulating cover layer 19 and Neither test insulating layer 28 is formed. In this case, the first insulation layer inspection probe 42 contacts the horizontal frame 23 without contacting the inspection insulation layer 28 .

Next, a voltage application device (not shown) applies a voltage to the wiring 15 via a second conductor inspection probe (not shown), and a first voltage detection circuit (not shown) connected to the first conductor inspection probe 41 (not shown) checks wiring 15 for breaks and/or shorts depending on whether it senses voltage.

A voltage applying device (not shown) applies a voltage to the inspection conductor layer 26 via the second insulating layer inspection probe 43 .

When the inspection insulating layer 28 is formed, the first insulating layer inspection probe 42 is in contact with the inspection insulating layer 28 and the conduction with the lateral frame 23 is blocked. A second voltage sensing circuit (not shown) connected to probe 42 senses no voltage. This confirms that the second insulating cover layer 19 and the inspection insulating layer 28 are formed.

On the other hand, when the inspection insulating layer 28 is not formed, the first insulating layer inspection probe 42 is in contact with the horizontal frame 23, so the voltage from the second insulating layer inspection probe 43 is It is detected by a second voltage detection circuit (not shown) connected to the first insulation layer inspection probe 42 via the frame 23 and the first insulation layer inspection probe 42 . This confirms that the second insulating cover layer 19 and the inspection insulating layer 28 are not formed.

That is, by bringing the first insulating layer inspection probe 42 into contact with the inspection insulating layer 28 and inspecting the continuity with the lateral frame 23 , it is confirmed whether or not the second insulating cover layer 19 is formed.

Thus, the inspection process for one suspension group 2 (that is, inspection for disconnection and/or short circuit of wiring 15 and inspection for defective formation of second insulating cover layer 19) is completed.

Thereafter, the inspection jig 40 is moved and the inspection process is repeated so that all the suspension groups 2 are subjected to the inspection process.

After the inspection process for all the suspension groups 2 is completed, the plurality of connecting portions 7 are cut to separate the plurality of suspension boards with circuit 5 from the frame 6 .

As described above, a plurality of suspension boards with circuit 5 are manufactured.

According to the method for manufacturing the suspension board with circuit 5 described above, as shown in FIG. After the varnish is coated on one side and the other side at once, the coated varnish is exposed and developed to form an inspection insulating layer 28 in the same process as the formation of the second insulating cover layer 19, as shown in FIG. 7C.

Therefore, when the steps of forming the second insulating cover layer 19 and the inspection insulating layer 28 are normally performed, both the second insulating cover layer 19 and the inspection insulating layer 28 are formed, while the second insulating cover layer 19 and the inspection insulating layer 28 are both formed. In the process of forming the inspection insulating layer 28, if an error occurs, for example, exposure is not performed, both the second cover insulating layer 19 and the inspection insulating layer 28 are not formed.

As a result, as shown in FIG. 5, when the first insulating layer inspection probe 42 comes into contact with the inspection insulating layer 28 and the conduction with the lateral frame 23 is blocked, the second insulating cover layer 19 is not normally formed. If the first insulating layer inspection probe 42 is in contact with the horizontal frame 23 without contacting the inspection insulating layer 28 and is electrically connected, it can be confirmed that the second insulating cover layer 19 is not formed.

In other words, it is possible to inspect the formation defect of the second insulating cover layer 19 using a simple method.

In particular, since the second insulating cover layer 19 does not affect the continuity of the conductive pattern 10 , it is difficult to check for defective formation of the second insulating cover layer 19 in the continuity test of the conductive pattern 10 . On the other hand, according to the above method, it is possible to smoothly inspect the second insulating cover layer 19 for defective formation.

As shown in FIG. 1, in the assembly sheet 1, the inspection insulating layer 28 is arranged on the supporting portion 3, so that the inspection process in the manufacturing method of the suspension board with circuit 5 can be smoothly carried out. Formation defects of the second cover insulating layer 19 can be inspected.

Moreover, as shown in FIG. 5 , the thickness of the inspection insulating layer 28 is equal to or greater than the thickness of the second cover insulating layer 19 . Therefore, when the first insulating layer inspection probe 42 is brought into contact with the inspection insulating layer 28 from the thickness direction to inspect continuity with the lateral frame 23, the inspection insulating layer 28 and the first insulating layer inspection probe 42 are brought into contact with each other. stable contact. As a result, it is possible to further improve the inspection accuracy for defective formation of the second insulating cover layer 19 .

Further, as shown in FIG. 4, the longitudinal dimension of the inspection insulating layer 28 is within the above range, and the alignment direction dimension of the inspection insulating layer 28 is within the above range. Therefore, when the first insulation layer inspection probes 42 are brought into contact with the inspection insulation layer 28 to inspect continuity with the horizontal frame 23, the inspection insulation layer 28 and the first insulation layer inspection probes 42 are brought into contact with each other more stably. can be made

<Modification>
In the above-described embodiment, the inspection insulating layer 28 is formed in the same process as the second insulating cover layer 19 and is used for inspection of formation defects of the second insulating cover layer 19. However, the configuration of the inspection insulating layer is It is not limited to this.

For example, as shown in FIG. 8, an inspection insulating layer may be formed in the same process as the insulating base layer 9 and used to inspect for defective formation of the insulating base layer 9 . In this case, the inspection base layer 25 does not have the first opening 25A, and the portion of the inspection base layer 25 exposed from the communication port 27A is defined as the inspection insulating layer 44 .

Further, as shown in FIG. 9, the inspection insulating layer can be formed in the same process as the first insulating cover layer 18 and used for inspection of formation defects of the first insulating cover layer 18 . In this case, the inspection cover layer 27 does not have the communication port 27A and is filled so as to drop into the first opening 25A of the inspection base layer 25 . A portion of the inspection cover layer 27 located within the first opening 25</b>A is configured as an inspection insulating layer 45 .

Also, as shown in FIG. 10, a plurality of inspection insulating layers can be provided.

For example, on the horizontal frame 23, a first inspection insulating layer 46 formed in the same process as the base insulating layer 9, a second inspection insulating layer 47 formed in the same process as the first cover insulating layer 18, and a second cover insulating layer The layer 19 and the third inspection insulating layer 48 formed in the same process may be spaced apart from each other. This makes it possible to collectively inspect for defects in the insulating base layer 9, the first insulating cover layer 18, and the second insulating cover layer 19 in the inspection process.

Further, as shown in FIG. 11 , the suspension board with circuit 5 may be provided with a second conductor pattern 50 on one surface of the first insulating cover layer 18 in the thickness direction. In this case, the first insulating cover layer 18 is an intermediate insulating layer arranged between the conductor pattern 10 and the second conductor pattern 50 . The second insulating cover layer 19 is arranged on one side in the thickness direction of the first insulating cover layer 18 so as to cover the second conductor pattern 50 .

In such a mode, as shown in FIG. 9, an inspection insulating layer 45 formed in the same process as the first insulating cover layer 18 may be arranged on the horizontal frame 23, and as shown in FIG. On the frame 23 , a first inspection insulating layer 46 formed in the same process as the base insulating layer 9 , a second inspection insulating layer 47 formed in the same process as the first cover insulating layer 18 , and a second cover insulating layer 19 . A third inspection insulating layer 48 formed by the same process may be arranged.

In addition, in the above embodiment, the inspection unit 4 includes the inspection base layer 25, the inspection conductor layer 26, the inspection cover layer 27, and the inspection insulating layer 28, but the configuration of the inspection unit 4 is Not limited. For example, as shown in FIG. 12, the inspection section 4 may consist of only the inspection insulating layer 28 .

In this case, for example, in the inspection process, a voltage is applied to the metal support 8 via the ground wiring included in the suspension board with circuit 5, and the first insulating layer inspection probes 42 are brought into contact with the inspection insulating layer 28, Conductivity with the horizontal frame 23 is inspected.

Further, in the above-described embodiment, one inspection unit 4 corresponds to each suspension group 2, but the arrangement and number of inspection units 4 are not particularly limited. Only one inspection unit 4 may be provided in the aggregate sheet 1 . Also, a plurality of inspection units 4 may be provided for one suspension group 2 .

In the above-described embodiment, the cover film 32 is a negative type in which the exposed portion is insolubilized and the unexposed portion is soluble. It may be a positive type in which is solubilized. In this case, the photomask 33 has a pattern opposite to that of the embodiment described above.

These can also provide the same effects as the above-described embodiment. Further, the above-described embodiment and modifications can be appropriately combined.

REFERENCE SIGNS LIST 1 assembly sheet 3 support part 4 inspection part 5 suspension board with circuit 8 metal support 9 base insulating layer 10 conductor pattern 11 cover insulating layer 12 metal supporting layer 18 first cover insulating layer 19 second cover insulating layer 28 inspection insulating layer 44 inspection insulation layer 45 inspection insulation layer 46 first inspection insulation layer 47 second inspection insulation layer 48 third inspection insulation layer

Claims (5)

providing a metal support layer;
forming a first insulating layer on one side in the thickness direction of the metal support layer;
forming a conductor pattern on one surface of the first insulating layer in the thickness direction;
forming a second insulating layer on one side of the first insulating layer in the thickness direction;
inspecting the formation defects of the first insulating layer and/or the second insulating layer;
In the step of forming the first insulating layer and/or the step of forming the second insulating layer, the thickness of the metal support layer is reduced by the same step as the step of forming the first insulating layer and/or the second insulating layer. forming an inspection insulating layer at a position different from the first insulating layer on one side in the direction;
A method of manufacturing a suspension board with circuit, wherein in the inspecting step, a probe is brought into contact with the inspection insulating layer to inspect continuity with the metal support layer. The step of forming the second insulating layer includes:
forming a first insulating cover layer on one side in the thickness direction of the first insulating layer so as to cover the conductor pattern;
forming a second insulating cover layer on one surface in the thickness direction of the first insulating cover layer,
The step of forming the second insulating cover layer includes:
A step of collectively applying a varnish containing a photosensitive resin to the one surface of the first insulating cover layer in the thickness direction and a position different from the first insulating layer on the one surface of the metal support layer in the thickness direction. and,
2. The method of manufacturing a suspension board with circuit according to claim 1, wherein the applied varnish is exposed and developed to simultaneously form the second insulating cover layer and the inspection insulating layer. A suspension board with circuit assembly comprising a plurality of suspension boards with circuit,
a metal support layer including a plurality of suspension portions corresponding to the plurality of suspension boards with circuit and a support portion collectively supporting the plurality of suspension boards with circuit;
a first insulating layer disposed on one surface in the thickness direction of the suspension portion;
a conductor pattern arranged on one surface in the thickness direction of the first insulating layer;
a second insulating layer arranged on one side of the first insulating layer in the thickness direction;
an inspection unit disposed on the support portion;
with
The inspection unit
an inspection base layer disposed on one side in the thickness direction of the metal support layer;
an inspection conductor layer arranged on one side in the thickness direction of the inspection base layer;
with
The inspection base layer has a second opening penetrating the inspection base layer in the thickness direction,
The inspection conductor layer includes an inspection terminal and a via section that is continuous with the inspection terminal,
a central portion of the via portion is recessed into the second opening to be filled and is in contact with the metal support layer;
The inspection unit further
and an inspection insulating layer arranged on one side in the thickness direction of the supporting portion for inspecting formation defects of the first insulating layer and/or the second insulating layer. board assembly. A suspension board with circuit assembly comprising a plurality of suspension boards with circuit,
a metal support layer including a plurality of suspension portions corresponding to the plurality of suspension boards with circuit and a support portion collectively supporting the plurality of suspension boards with circuit;
a first insulating layer disposed on one surface in the thickness direction of the suspension portion;
a conductor pattern arranged on one surface in the thickness direction of the first insulating layer;
a second insulating layer arranged on one side of the first insulating layer in the thickness direction;
an inspection insulating layer arranged on one side in the thickness direction of the supporting portion for inspecting formation defects of the first insulating layer and/or the second insulating layer;
The second insulating layer is
a first insulating cover layer arranged on one side in the thickness direction of the first insulating layer so as to cover the conductor pattern;
a second insulating cover layer disposed on one surface in the thickness direction of the first insulating cover layer,
The suspension board assembly with circuit, wherein the thickness of the inspection insulating layer is equal to or greater than the thickness of the second insulating cover layer. a dimension of the inspection insulating layer in a first direction perpendicular to the thickness direction is 30 μm or more and 500 μm or less;
5. The suspension board with circuit assembly according to claim 3, wherein the dimension of said inspection insulating layer in a second direction perpendicular to both said thickness direction and said first direction is 30 μm or more and 500 μm or less. body.

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