JP2012142082A - Substrate for suspension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate for a suspension having grounding means capable of sufficiently preventing electrostatic destruction and suppressing noises with few faults when components to be arranged on the substrate for the suspension are arranged.SOLUTION: The substrate for the suspension includes: a metal substrate which has an opening for a ground terminal; an insulating layer which is formed on the metal substrate and is arranged so as to surround the periphery of the opening for the ground terminal; a wire for grounding which is formed on the insulating layer and is arranged so as to cover the opening for the ground terminal; a protective plated layer which is formed on the surface of the wire for grounding; and a ground terminal which is formed by filling the opening for the ground terminal with a material for a ground terminal and is connected to the metal substrate and the wire for grounding.

Description

  The present invention relates to a suspension substrate having a grounding means that has few obstacles when arranging components to be disposed on a suspension substrate and can sufficiently prevent electrostatic breakdown and suppress noise.

  In recent years, due to the spread of the Internet and the like, there has been a demand for an increase in the amount of information processing of personal computers and an increase in information processing speed, and along with this, the capacity of hard disk drives (HDD) incorporated in personal computers has increased. Increasing information transmission speed is required. In addition, a component called a magnetic head suspension that supports the magnetic head used in the HDD also has a signal line such as a copper wiring directly formed on a stainless steel spring from a conventional type in which a signal line such as a gold wire is connected. The so-called wireless suspension is now integrated into a wiring integrated type (flexure).

  Recently, there has been an increase in demand for HDDs mounted on various small devices such as portable applications. For this reason, HDDs have become denser and magnetic heads have become smaller, and magnetic heads have become more sensitive. It is easily affected by static electricity. Therefore, there has been a problem that the characteristics of the small magnetic head element are changed by the electric charge accumulated in the slider, or in the worst case, it is destroyed.

  Further, as another problem, in order to improve the signal transmission speed and accuracy of the HDD, in recent years, there has been a tendency to use a higher frequency electric signal. However, as the frequency becomes higher, the noise of the transmitted electric signal becomes smaller. There was a problem of increasing.

  For these problems, electrical connection using a conductive resin has been performed between the magnetic head slider and the suspension. However, since the current conductive resin is not sufficiently conductive, there is a problem that static electricity cannot be sufficiently removed by connection using such a conductive resin.

On the other hand, in Patent Document 1, in order to prevent electrostatic breakdown and suppress noise, a metal pad is formed on the surface of the insulating layer laminated on the metal substrate, and the metal substrate is further formed on the insulating layer and the metal pad. There has been proposed a grounding means in which a ground terminal for connecting the metal substrate and the metal pad is formed in a through hole formed so as to be exposed. According to such a grounding means, it is possible to prevent the slider from being electrostatically damaged by connecting the grounding wiring connected to the slider to the metal pad. Further, by installing the metal pad in the vicinity of the signal wiring, it is possible to suppress noise generated on the suspension substrate and to stabilize the signal passing through the signal wiring.
However, in the grounding means disclosed in Patent Document 1, the ground terminal is formed on the insulating layer side of the suspension board on which the signal wiring, the slider, and the like are mounted, and the suspension board has the insulating layer side. Since the shape protrudes from the surface of the slider, there is a possibility that when the components such as the slider are arranged on the suspension board, the ground terminal may be an obstacle, and it may be difficult to arrange the components such as the slider. was there.

JP 2006-202359 A

  The present invention has been made in view of the above problems, and there are few obstacles when placing components to be placed on a suspension board, and grounding means capable of sufficiently preventing electrostatic breakdown and suppressing noise. The main object is to provide a suspension substrate having the following.

  To achieve the above object, the present invention provides a metal substrate having a ground terminal opening, an insulating layer formed on the metal substrate and arranged to surround the ground terminal opening, A grounding wiring formed on the insulating layer and arranged to cover the ground terminal opening, a protective plating layer formed on a surface of the grounding wiring, and a ground terminal opening There is provided a suspension substrate, which is formed by being filled with a terminal material, and has a ground terminal connected to the metal substrate and the ground wiring.

According to the present invention, since the ground terminal material is formed on the metal substrate side of the suspension substrate of the present invention, the ground terminal material is placed on the suspension substrate with a component such as a slider. It can not be an obstacle to placement.
Moreover, electrostatic breakdown prevention and noise suppression can be sufficiently achieved.

  In the present invention, it is preferable that the maximum film thickness portion of the ground terminal material is inside the surface of the metal substrate on the side where the insulating layer is not formed. When manufacturing the HDD using the suspension substrate of the present invention, the maximum film thickness portion of the ground terminal material is inside the surface of the metal substrate on which the insulating layer is not formed. This is because the ground terminal material can be less likely to interfere with other parts constituting the HDD.

  The present invention has a grounding means that has a very high degree of freedom in design because there are few obstacles when placing components to be placed on a suspension board, and further can sufficiently prevent electrostatic breakdown and suppress noise. The suspension substrate can be provided.

It is a schematic plan view which shows an example of the board | substrate for suspensions of this invention. It is a schematic sectional drawing which shows an example of the board | substrate for suspensions of this invention. It is explanatory drawing explaining the ground terminal used for this invention. It is explanatory drawing explaining the ground terminal used for this invention. It is explanatory drawing explaining the ground terminal used for this invention. It is explanatory drawing explaining the ground terminal used for this invention. It is explanatory drawing explaining the ground terminal used for this invention. It is process drawing which shows an example of the manufacturing method of the board | substrate for suspensions of this invention. It is process drawing which shows an example of the manufacturing method of the board | substrate for suspensions of this invention. It is a schematic plan view which shows an example of the conventional board | substrate for suspensions. It is a schematic sectional drawing which shows an example of the conventional board | substrate for suspensions.

Hereinafter, the suspension substrate of the present invention will be described in detail.
The suspension substrate of the present invention includes a metal substrate having a ground terminal opening, an insulating layer formed on the metal substrate and arranged to surround the ground terminal opening, and on the insulating layer. The ground terminal material is formed to cover the ground terminal opening, the protective plating layer is formed on the surface of the ground wiring, and the ground terminal material is formed in the ground terminal opening. It is formed by being filled, and has a ground terminal connected to the metal substrate and the grounding wiring.

  Such a suspension substrate of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing an example of a suspension substrate according to the present invention, and FIG. 2 is a cross-sectional view taken along the line AA of FIG. As illustrated in FIGS. 1 and 2, the suspension substrate 10 of the present invention is formed on the metal substrate 1 having the ground terminal opening 3, the metal substrate 1, and the ground terminal opening 3. An insulating layer 2 arranged so as to surround the periphery, a grounding wiring 4 formed on the insulating layer 2 so as to cover the opening 3 for the ground terminal, and a surface of the grounding wiring 4 The protective plating layer 5 is formed, and the ground terminal material 6 is filled in the ground terminal opening 3, and the ground terminal 7 is connected to the metal substrate 1 and the ground wiring 4. Is.

Conventionally, as illustrated in FIG. 11, which is a plan view illustrated in FIG. 10 and a cross-sectional view taken along line BB in FIG. 10, the ground terminal opening 103 is formed on the metal substrate 101. The grounding wiring 104 formed so as to surround the ground terminal opening 103 and covered with the protective plating layer 105 is connected to the metal substrate 101 and the grounding wiring 104. A suspension substrate 100 having a ground terminal material 106 filled in and a ground terminal 107 formed by filling the ground terminal opening 106 with the ground terminal material 106 has been used. In such a conventional suspension substrate, the ground terminal material protrudes from the insulating layer side surface of the suspension substrate.
Here, since the suspension substrate is usually provided with a component such as a slider on the side where the insulating layer is formed, the ground terminal material has a shape protruding from the surface of the suspension substrate on the insulating layer side. When placing components such as a slider on the suspension board, there is a problem that the ground terminal material may be an obstacle, making it difficult to place the slider and other components. For this reason, conventionally, the ground terminal material is filled with the ground terminal material so that the ground terminal material does not become an obstacle when arranging components such as a slider mounted on the suspension board. It was necessary to design the position.

On the other hand, according to the present invention, the ground terminal material is formed on the metal substrate side of the suspension substrate of the present invention, and the ground terminal material protrudes from the insulating layer side of the suspension substrate. Therefore, the ground terminal material does not become an obstacle when a component such as a slider is arranged on the suspension substrate.
As a result, since it is not necessary to consider the presence or absence of obstacles when placing components such as a slider, the degree of freedom in designing the position of the ground terminal opening and the like can be increased.
Further, since the grounding wiring is connected to the metal substrate via the ground terminal, when such grounding wiring is connected to, for example, a slider, the electrostatic breakdown of the slider is prevented. Can be sufficiently achieved. In addition, when the grounding wiring is installed in the vicinity of the signal wiring formed on the suspension board of the present invention, it is possible to sufficiently suppress noise generated on the suspension board, The signal passing through the signal wiring can be sufficiently stabilized.

  The suspension substrate of the present invention has a metal substrate, an insulating layer, a grounding wiring, a protective plating layer, and a ground terminal. Hereinafter, each structure of the suspension substrate of the present invention will be described.

(1) Ground terminal The ground terminal used in the present invention is formed by filling a ground terminal material in a ground terminal opening formed in a metal substrate described later.

(A) Opening for ground terminal The opening for ground terminal used in the present invention is formed on a metal substrate described later, and its periphery is surrounded by an insulating layer described later.

The formation position of the opening for the ground terminal used in the present invention is not particularly limited as long as it can be covered by the grounding wiring described later, and depends on the use of the suspension substrate of the present invention. Can be set as appropriate. Specifically, it may be provided at the tip of the suspension substrate on which the magnetic head slider is mounted.
When provided at the tip of the suspension substrate, the ground terminal opening may be formed at a position away from the slider installation position.
Further, as illustrated in FIG. 3, it may be formed at a position adjacent to the slider installation position 20. In the present invention, since the ground terminal material filled in the ground terminal opening does not protrude from the insulating layer side of the suspension substrate, the ground terminal opening is a slider on which a slider is installed. This is because the ground terminal material does not come into contact with the slider even when it is formed at a location adjacent to the installation position.
Furthermore, as illustrated in FIG. 4, it may be formed so as to overlap with the slider installation position 20 in plan view. Since the ground terminal material does not protrude from the insulating layer side of the suspension substrate, a part of the slider is in contact with the ground wiring formed to cover the ground terminal opening. Even in this case, the slider can be stably mounted on the suspension substrate.
Furthermore, as illustrated in FIG. 5, it may be provided in a portion other than the tip of the suspension substrate. In FIG. 5, the ground terminal opening 3 and the ground wiring 4 formed so as to cover the ground terminal opening 3 are formed between the signal wiring 14 and the signal wiring 14.
In FIGS. 3 to 5, drawing of the protective plating layer and the ground terminal material constituting the suspension substrate of the present invention is omitted for easy explanation of the formation position of the ground terminal opening.

The shape of the opening for ground terminal used in the present invention in plan view is not particularly limited as long as the ground terminal material can be filled and the ground terminal can be formed. , Circular, elliptical, quadrilateral or pentagonal polygonal shapes, comb shapes, cross shapes, rod shapes, and the like. Usually, a circular one is used.
In the present invention, when the shape of the opening for the ground terminal is circular, the diameter is preferably within a range of 30 μm to 300 μm, and more preferably within a range of 30 μm to 200 μm. In particular, it is preferably in the range of 50 μm to 100 μm. This is because, when the ground terminal opening is filled with the ground terminal material, the connection between the metal substrate and the ground wiring, which will be described later, can be made stable. In addition, when the ground terminal opening is formed between the signal wiring and the signal wiring, the formation is easy.

(B) Ground Terminal Material The ground terminal material used in the present invention fills the opening for the ground terminal and is connected to the ground wiring and the metal substrate.

The type of the ground terminal material used in this embodiment is not particularly limited as long as it is a conductive material having excellent conductivity and can fill the opening for the ground terminal. However, it is preferable that the material has excellent adhesion to the upper metal substrate and the ground wiring. Examples of such a material include metals and conductive resins. In the present invention, metal is preferably used. Specifically, silver (Ag), gold (Au), copper (Cu), nickel (Ni) and the like can be used, and among them, silver (Ag) and nickel (Ni) can be preferably used. Nickel (Ni) can be preferably used. This is because it is highly conductive and inexpensive.
These materials can be identified by XPS (X-ray Photoelectron Spectroscopy).
Moreover, as conductive resin, the resin which has electroconductivity independently, and the mixture of resin and a metal can be mentioned.

As a method for filling the ground terminal material used in the present invention, when the ground terminal material is a metal, various methods such as electrolytic plating, electroless plating, and soldering can be used. Electrolytic plating is preferable because the resistance value of the terminal can be lowered and miniaturization is easy.
When the ground terminal material is a conductive resin, a conductive resin dispenser or a printing method such as printing can be used.

As the cross-sectional shape of the ground terminal material used in the present invention, any material may be used as long as it fills the opening for the ground terminal and is connected to the ground wiring and the metal substrate. Specifically, as illustrated in FIGS. 6 and 7, the ground terminal material 6 and the metal substrate 1 are connected only at the side wall in the ground terminal opening 3 of the metal substrate 1. The maximum film thickness portion of the ground terminal material may be formed so as to be inside the lower surface of the metal substrate, which is the surface of the metal substrate on which the insulating layer is not formed.
Here, in FIG. 6, the ground terminal material 6 is connected at a part of the side wall in the ground terminal opening 3 of the metal substrate 1. In FIG. 7, the ground terminal material 6 is formed so as to cover all the side walls in the ground terminal opening 3 of the metal substrate 1.
Further, as illustrated in FIG. 2, the ground terminal material 6 and the metal substrate 1 are connected to each other on the side wall and the lower surface in the ground terminal opening 3 of the metal substrate 1. May be. Since the ground terminal material is formed so as to be in contact with the metal substrate over a wide area, the connection between the metal substrate and the ground wiring via the ground terminal material can be made more stable. It is. In such a case, the ground terminal material may be formed so as to overlap the signal wiring and the slider installation position in plan view. This is because the signal wiring and the like are usually arranged on the insulating layer side of the suspension substrate and do not interfere with the ground terminal material.
The maximum film thickness portion of the ground terminal material refers to a portion of the surface of the ground terminal material that has the longest distance from the surface of the protective plating layer in the ground terminal opening. Further, the maximum film thickness portion of the ground terminal material is inside the lower surface of the metal substrate. When the surface of the lower surface of the metal substrate is extended to the opening for the ground terminal, the ground terminal material It means that the maximum film thickness portion is located on the ground wiring side from the surface.

  As the cross-sectional shape of the ground terminal material used in the present invention, any of the above can be suitably used. In the present invention, the maximum film thickness portion of the ground terminal material is the metal substrate. It is preferable to be formed so as to be inside the lower surface of the metal substrate. Particularly, the maximum film thickness portion of the ground terminal material is formed to be inside the lower surface of the metal substrate, and The ground terminal material is preferably formed so as to cover all the side walls in the ground terminal opening of the metal substrate. Since the maximum film thickness portion of the ground terminal material is inside the lower surface of the metal substrate, the ground terminal material constitutes the HDD even when the suspension substrate is used for the HDD. This is because there is little risk of interference with other parts. In addition, since the ground terminal material is formed so as to cover all of the side walls in the ground terminal opening of the metal substrate, the connection between the metal substrate and the ground wiring is stable. Because it can be done.

  In addition, when the ground terminal material is connected to the metal substrate on the side wall and the lower surface in the opening for the ground terminal, the thickness of the ground terminal material on the lower surface of the metal substrate. Is preferably in the range of 15 μm to 35 μm. When the suspension substrate according to the present invention is used for an HDD, the ground terminal material can be less likely to interfere with other parts constituting the HDD. is there.

The film thickness of the ground terminal material used in the present invention is not particularly limited as long as it can be stably connected to the metal substrate and grounding wiring described later, and the insulation described later. Although it varies depending on the film thickness of the layer, it is preferably within a range of 15 μm to 50 μm, and more preferably within a range of 15 μm to 35 μm. If the thickness is smaller than the above range, it may be difficult to stably connect to the metal substrate and the ground wiring, or static electricity and noise may not be sufficiently removed. On the other hand, if the thickness is larger than the above range, when the suspension board of the present invention is used in an HDD, the suspension board may interfere with other parts constituting the HDD.
The film thickness in the ground terminal opening is the shortest distance from the surface on the ground terminal opening side of the protective plating layer covering the ground wiring to the surface of the ground terminal material. It means something.
In the present invention, the film thickness of the ground terminal material may be formed so as to be within a desired range from the beginning, and is ground after being formed thicker than the desired range. It may be adjusted accordingly.

(C) Ground terminal The ground terminal used in the present invention is formed by filling the ground terminal opening with the ground terminal material, and is connected to a ground wiring and a metal substrate described later.

  The resistance value of the ground terminal is not particularly limited as long as it can prevent electrostatic breakdown and suppress noise. For example, it is preferably 5Ω or less, and more preferably 1Ω or less. It is particularly preferable that it is in the range of 0.10Ω to 0.25Ω.

(2) Grounding wiring The grounding wiring used in the present invention is formed on an insulating layer, which will be described later, and is disposed so as to cover the ground terminal opening.

The formation position of the grounding wiring used in the present invention is not particularly limited as long as it can achieve desired electrostatic breakdown prevention and noise suppression, and is used for the application of the suspension substrate of the present invention. It can be set accordingly. Specifically, it may be provided at the tip of the suspension substrate on which the magnetic head slider is mounted.
When it is provided at the tip of the suspension substrate, it is formed so as to extend from the ground terminal opening formed at a position away from the slider installation position to a position where it can be connected to the slider. May be.
Further, as illustrated in FIG. 3 described above, the grounding wiring 4 may be formed so as to surround the slider installation position 20. Usually, since the suspension substrate and the slider are bonded using an adhesive, the grounding wiring is formed so as to surround the slider installation position where the suspension substrate and the slider are bonded. This is because it is possible to prevent the adhesive from flowing out.

Furthermore, as illustrated in FIG. 4 described above, the grounding wiring 4 may be formed so as to overlap the slider installation position 20 in plan view. Since the ground terminal material does not have a shape protruding from the insulating layer side of the suspension substrate, the slider is mounted on the suspension substrate even when a part of the slider is in contact with the ground wiring. It is because it can be stably mounted on the top. In addition, the contact between the slider and the grounding wiring makes it possible to remove static electricity more efficiently than when the slider is connected to the metal substrate via a conductive resin. .
Furthermore, as illustrated in FIG. 5, it may be provided in a portion other than the tip of the suspension substrate. In FIG. 5, the ground terminal opening 3 and the ground wiring 4 formed so as to cover the ground terminal opening 3 are formed between the signal wiring 14 and the signal wiring 14.

  Examples of the material for the grounding wiring used in the present invention include copper (Cu).

  The thickness of the grounding wiring used in the present invention is not particularly limited as long as the desired electrical conductivity can be exhibited, but it is usually preferably in the range of 6 μm to 18 μm, especially 8 μm. It is preferable to be within a range of ˜12 μm. It is because sufficient electroconductivity can be exhibited by being in the above range, and electrostatic breakdown prevention and noise removal can be sufficiently achieved.

  The line width of the ground wiring used in the present invention is not particularly limited as long as it can be formed so as to cover the opening for the ground terminal, but is in the range of 10 μm to 100 μm. It is preferable that it is in the range of 15 micrometers-50 micrometers especially. This is because, by being in the above range, for example, it can be easily installed between signal wirings with a narrow pitch.

(3) Insulating layer The insulating layer used in the present invention is formed on a metal substrate, which will be described later, and is formed so as to surround the periphery of the opening for ground terminal of the metal substrate.

  Examples of the material for the insulating layer include polyimide (PI).

  The thickness of the insulating layer is not particularly limited as long as a desired insulating property can be exhibited, but is usually about 5 μm to 30 μm.

(4) Metal substrate The metal substrate used for this invention has the said opening part for ground terminals, Comprising: It has electroconductivity. Moreover, since it is used for suspension applications, it usually has an appropriate spring property.

  Examples of the material of the metal substrate include SUS.

  In this invention, it is preferable to have a conductive layer in the area | region in which the said ground terminal material is formed, such as the side surface by the side of the opening part for ground terminals among the surfaces of the said metal substrate. This is because by providing the conductive layer, conduction by the ground terminal becomes more efficient. Specific examples of the material for the conductive layer include copper (Cu). The conductive layer can be formed by, for example, a plating method.

  The thickness of the metal substrate is not particularly limited as long as the desired spring characteristics can be exhibited, and varies depending on the material of the metal substrate, but is usually in the range of 10 μm to 30 μm. It is preferable that it is in the range, and it is preferable that it exists in the range of 15 micrometers-25 micrometers especially.

(5) Protective plating layer The protective plating layer used in the present invention is directly formed on the surface of the ground wiring. The material of the grounding wiring is usually copper (Cu) and is likely to be corroded. For this reason, the grounding wiring can be made resistant to corrosion by forming a protective plating layer made of another metal on the surface of the grounding wiring.

The protective plating layer used in the present invention only needs to be formed so as to cover at least the entire surface of the grounding wiring that is not protected from corrosion or the like by a coverlay or the like to be described later. . Therefore, it may be formed so as to cover the entire surface of the grounding wiring, or only an exposed portion that is not covered with a coverlay or the like may be formed.
In addition, the protective plating layer in the present invention is usually formed also on the surface in the ground terminal opening of the ground wiring. As shown in the manufacturing method of the suspension substrate of the present invention to be described later, when a protective plating layer is formed on the grounding wiring, the surface in the ground terminal opening of the grounding wiring is usually coated with a plating solution. This is because it is exposed.

  As a material for forming the protective plating layer used in the present invention, nickel (Ni) and gold (Au) can be used, and among them, gold (Au) can be preferably used. This is because the metal having excellent corrosion resistance can make the grounding wiring resistant to corrosion.

  The thickness of the protective plating layer used in the present invention is preferably 5 μm or less, and more preferably in the range of 1 μm to 2 μm. It is because it is easy to form the said protective plating layer stably in the surface of the said grounding wiring because it is the said range.

  As a method for forming a protective plating layer used in the present invention, for the purpose of cost reduction, a signal wiring and a ground wiring for transmitting an electrical signal or the like on a suspension substrate are usually provided on the insulating layer described above. The signal wiring and the ground wiring are formed to be connected via a connection wiring. Next, a method in which a protective plating layer is formed on the surfaces of the signal wiring and the ground wiring by using the signal wiring and the ground wiring as a power feeding layer is preferably used. In addition, a method of forming by electroless plating without forming the connection wiring for connecting the ground wiring and the signal wiring can also be used.

(6) Suspension substrate The suspension substrate of the present invention may have a coverlay (CL) on the insulating layer, if necessary. Although it does not specifically limit as thickness of the said coverlay, Usually, it is about 5 micrometers-about 30 micrometers. The material of the cover lay is not particularly limited, and the same material as the cover lay used for a general flexible substrate or the like can be used.

The suspension board of the present invention has signal wiring for transmitting an electrical signal in addition to the grounding wiring described above. The signal wiring usually includes a write wiring and a read wiring. The signal wiring may be formed of the same material as the grounding wiring described above, or may be formed of a different material, but is usually formed of the same material (the same wiring forming layer). . This is because the cost can be reduced.
Further, the pitch width between the signal wirings used in the present invention is preferably in the range of 60 μm to 200 μm at the narrowest portion, and more preferably in the range of 60 μm to 100 μm. This is because the suspension substrate of the present invention can exert its effect more by being in the above range.

  The method for manufacturing the suspension substrate according to the present invention is not particularly limited as long as each component of the suspension substrate can be accurately placed at a desired position. For example, FIG. As shown in FIG. 2, the metal substrate 1, the insulating layer forming layer 2 'made of the material constituting the insulating layer, and the grounding wiring forming layer made of the material constituting the grounding wire are formed on the metal substrate 1. 4 ′ is formed. Next, a photoresist 11 such as a dry film is provided on both surfaces of the laminate, and patterned into a predetermined shape (FIG. 8B). Thereafter, the metal substrate 1 and the grounding wiring forming layer 4 'are patterned by etching (FIG. 8C), and the photoresist 11 is peeled off, whereby the ground terminal opening 3 and the grounding wiring 4 are removed. (FIG. 8D). At this stage, the signal wiring 14 is also formed at the same time if necessary.

Subsequently, as shown in FIG. 9A, a photoresist 11 such as a dry film is provided and patterned into a predetermined shape. Next, the insulating layer forming layer 2 'is patterned by etching, and the photoresist 11 is peeled off to form the insulating layer 2 having an opening surrounding the ground terminal opening 3 (FIG. 9B). ).
Further, a protective plating layer 5 is formed on the surface of the ground wiring 4 using the ground wiring 4 as a power feeding layer (FIG. 9C).
Further, after that, a photoresist 11 such as a dry film is provided on both surfaces of the laminate, patterned into a predetermined shape (FIG. 9 (d)), and the ground wiring material is used as the power feeding layer. The metal 6 is filled in the opening 3 for the ground terminal to form the ground terminal 7 for connecting the metal substrate 1 and the grounding wiring 4, and then the photoresist 11 is peeled off, thereby The method for forming the suspension substrate 10 of the invention can be used (FIG. 9E).

  Here, FIGS. 8A to 8D are ground wiring forming steps, and FIGS. 9A to 9B are insulating layer forming steps. Moreover, FIG.9 (c) is a protective plating layer formation process, and FIG.9 (d)-(e) is a ground terminal formation process.

  The suspension substrate of the present invention is used for a magnetic head suspension or the like of a hard disk drive (HDD), and in particular, a magnetic head of a hard disk drive (HDD) having a high-density signal wiring with a narrow pitch. It is suitably used for a suspension substrate.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the technical idea described in the claims of the present invention has substantially the same configuration and exhibits the same function and effect regardless of the case. It is included in the technical scope of the invention.

Hereinafter, the present invention will be described more specifically with reference to examples.
[Example]
SUS304 (metal substrate) having a thickness of 20 μm, a polyimide layer (insulating layer forming layer) having a thickness of 10 μm, and a Cu wiring layer (wiring forming layer) made of electrolytic copper having a thickness of 9 μm were laminated in this order. A laminated body is prepared, and the ground terminal material as shown in FIG. 1 is formed on the metal substrate side by performing the following chemical etching or the like in the laminated body manufacturing method of the present invention described above. In addition, a suspension substrate having a grounding means having a larger outer diameter of the ground terminal material than the outer diameter of the ground wiring was obtained.

First, the Cu wiring layer and the metal substrate of the laminate were chemically etched to form a metal substrate having a ground wiring, a signal wiring, and a circular ground terminal opening having a diameter of 100 μm.
Here, the ground wiring was formed such that the outer diameter at the portion covering the opening for the ground terminal was 200 μm, and the line width at other portions was 25 μm.
The signal wiring has a line width of 25 μm, and the distance from the ground wiring is 25 μm in a region where the ground terminal opening is not formed, and in the region where the ground terminal opening is formed. It formed so that it might become 100 micrometers.

  Next, by chemically etching the polyimide layer with a photosensitive resist, an opening having the same diameter as the ground terminal opening is grounded at the same position as the ground terminal opening. The wiring for use was exposed.

  Next, nickel (Ni) was electroplated to the surface of the ground wiring and signal wiring by about 0.2 μm, and then gold (Au) was electroplated by about 1.5 μm to form a protective plating layer.

Thereafter, nickel (Ni) was filled as a ground terminal material, and the ground terminal material was filled by electrolytic plating using the ground wiring as a power feeding portion to form a ground terminal material. The nickel plating was performed until the electrodeposition started from the surface in the ground terminal opening of the grounding wiring until it was connected to the side wall and the lower surface in the ground terminal opening of the metal substrate. After completion of electroplating, the nickel plating on the lower surface of the metal substrate had a circular shape with a diameter of 280 μm and a thickness of 20 μm.
Further, the outer diameter of the ground terminal material is larger than the outer diameter of the ground wiring on the ground terminal opening. However, the ground terminal material can be formed without obstructing other signal wiring. did it.

Furthermore, a suspension cover substrate was formed by applying a photosensitive coverlay for wiring protection, exposing and developing, and forming a coverlay of a predetermined shape.
The resistance value at the ground terminal of the suspension board thus obtained was 0.2Ω, and the same characteristics as the ground terminal in the grounding means of the conventional suspension board could be obtained.

DESCRIPTION OF SYMBOLS 1,101 ... Metal substrate 2,102 ... Insulating layer 2 '... Insulating layer forming layer 3, 103 ... Opening for ground terminal 4, 104 ... Grounding wiring 4' ... Grounding wiring forming layer 5, 105 ... Protection Plating layer 6, 106 ... Ground terminal material 7, 107 ... Ground terminal 10, 100 ... Suspension substrate 11 ... Photoresist 20 ... Slider installation position

Claims (2)

A metal substrate having a ground terminal opening;
An insulating layer formed on the metal substrate and arranged to surround the ground terminal opening;
A grounding wiring formed on the insulating layer and arranged to cover the opening for the ground terminal;
A protective plating layer formed on the surface of the ground wiring;
A suspension substrate, wherein the ground terminal opening is filled with a ground terminal material, and has a ground terminal connected to the metal substrate and the ground wiring.   2. The suspension substrate according to claim 1, wherein a maximum film thickness portion of the ground terminal material is inside a surface of the metal substrate on the side where the insulating layer is not formed.