JP2009118626A - Suspension substrate and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension substrate suppressing growth of an intermetallic compound layer generated on a contact interface between a connection portion and a gold plating layer and preventing deterioration of the connection portion. <P>SOLUTION: This suspension base board having a connection region includes: a conductive layer; the gold plating layer formed on a surface of the conductive layer to prevent corrosion of the conductive layer; the connection portion for electrically connecting the conductive layer and the member to be connected through the gold plating layer. The connection portion is made of Au-Sn alloy composed mostly of Au. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a suspension board capable of suppressing the growth of an intermetallic compound layer generated at a contact interface between a connection portion and a gold plating layer and preventing the deterioration of the connection portion, and a method for manufacturing the same.

  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 has been shifted to the integrated wiring type.

  The conductive layer used for the wiring of such a wireless suspension (suspension substrate) is electrically connected to other members (members to be connected) in several areas because of its function. Specifically, in the ground terminal region, the conductive layer (ground conductive layer) and the metal supporting board are electrically connected. In the gimbal region, the conductive layer (wiring portion) of the suspension board and an element such as a magnetic head slider are electrically connected. Furthermore, in the relay board connection region, the conductive layer (terminal part) of the suspension board and the terminal part of the relay board are electrically connected.

  As for a connection method in the ground terminal region, for example, Patent Document 1 discloses that a ground terminal for short-circuiting a wiring and a suspension board is provided on a suspension with wiring. Here, since the additive method is used in the formation process of the ground terminal, a power feeding layer forming step by a dry process and a wiring layer forming step by an electrolytic plating method are performed. On the other hand, with respect to the connection method in the gimbal region, for example, Patent Document 2 discloses that electrical connection is performed using a conductive resin between a magnetic head and a suspension.

  Regarding the connection method in the relay board connection region, for example, in Patent Document 3, a suspension member, a support member for attaching the suspension member, and the support member are attached to electrically connect the far end of the electrical conductor lead. A suspension system is disclosed that includes an electroreceptive pad member. Furthermore, it discloses that the far end of the electrical conductor lead and the electrical receiving pad member are connected by solder.

JP 2006-12205 A JP-A-8-1111015 Japanese Patent No. 3063901

  Currently, copper is often used as a material for the conductive layer existing in the ground terminal region, the gimbal region, or the relay substrate connection region. Moreover, since copper is easily corroded, the conductive layer is usually usually plated with gold. Therefore, the conductive layer and the connected member are usually electrically connected via gold plating. Here, when the connection portion is formed using, for example, a solder made of a Sn—Ag—Cu alloy, Au of gold plating diffuses into the solder, and an intermetallic compound layer grows at the contact interface between the two, and as a result, There is a problem that a crack occurs in the connection portion. Note that the growth of the intermetallic compound layer is prominent at high temperatures.

  The present invention has been made in view of the above circumstances, and a suspension board capable of suppressing the growth of an intermetallic compound layer generated at a contact interface between a connection portion and a gold plating layer and preventing deterioration of the connection portion. The main purpose is to provide.

  In order to solve the above problems, in the present invention, a conductive layer, a gold plating layer that is formed on the surface of the conductive layer and prevents corrosion of the conductive layer, the conductive layer and the connected member are combined with the gold layer. A suspension board having a connection region electrically connected via a plating layer, wherein the connection portion is formed of an Au-Sn alloy mainly composed of Au. A suspension board is provided.

  According to the present invention, the growth of the intermetallic compound layer can be suppressed at the contact interface between the connection portion and the gold plating layer by using the Au—Sn alloy containing Au as a main component. Thereby, for example, a suspension board having a ground terminal with low resistance and high durability can be obtained.

  In the said invention, it is preferable that Sn density | concentration of the said Au-Sn type alloy exists in the range of 15 weight%-37 weight%. This is because the melting point of the Au—Sn alloy can be lowered.

  In the said invention, it is preferable that Au concentration of the said Au-Sn type alloy is 80 weight%, and Sn concentration is 20 weight%. This is because it corresponds to the eutectic point of the Au—Sn alloy and has a low melting point.

  In the present invention, the conductive layer, the gold plating layer formed on the surface of the conductive layer and preventing corrosion of the conductive layer, and the conductive layer and the connected member are electrically connected via the gold plating layer. Suspension board comprising a connection region having a connection portion for connection, wherein the connection portion is made of an alloy having Au as a main component and a melting point of 450 ° C. or lower. Providing a substrate.

  According to the present invention, it is possible to suppress the growth of the intermetallic compound layer at the contact interface between the connecting portion and the gold plating layer by using an alloy containing Au as a main component and having a melting point of 450 ° C. or less. Thereby, for example, a suspension board having a ground terminal with low resistance and high durability can be obtained.

  In the above invention, the connection region is a ground terminal region, and the connection part electrically connects the conductive layer and the metal support substrate as the connected member through the opening of the insulating layer. It is preferable. This is because the conductive layer (ground conductive layer) and the terminal portion of the relay substrate can be satisfactorily connected.

  In the above invention, the conductive layer has an opening, and the connection portion electrically connects the metal support substrate exposed from the openings of the conductive layer and the insulating layer and the conductive layer. Preferably it is. This is because it is a general-purpose structure.

  In the above invention, the metal support substrate has an opening, and the connection portion electrically connects the conductive layer exposed from the opening of the metal support substrate and the insulating layer and the metal support substrate. It is preferable. This is because the wettability between the gold plating layer on the conductive layer and the solder is excellent, and pretreatment such as application of flux is unnecessary.

  In the above invention, it is preferable that the connection region is a gimbal region, and the connection part electrically connects the conductive layer and the element that is the connected member. This is because the conductive layer (wiring portion) of the suspension board and the element having the magnetic head can be satisfactorily connected.

  In the above invention, the element is preferably a magnetic head slider or an actuator. This is because it is used for general purposes.

  In the above invention, it is preferable that the connection region is a relay board connection region, and the connection part electrically connects the conductive layer and a terminal part of the relay board which is the connected member. This is because the conductive layer (terminal part) of the suspension board and the terminal part of the relay board can be satisfactorily connected.

  In the present invention, the conductive layer, the gold plating layer formed on the surface of the conductive layer and preventing corrosion of the conductive layer, and the conductive layer and the connected member are electrically connected via the gold plating layer. A suspension board having a connection region that is electrically connected to the suspension substrate, wherein the connection portion is formed by dropping an Au-Sn alloy mainly composed of Au in a molten state. There is provided a method for manufacturing a suspension board, comprising a connecting portion forming step.

  According to the present invention, for example, by using an Au 80% -Sn 20% alloy having a eutectic composition, the alloy can be melted at a relatively low temperature, and a connection portion can be efficiently formed.

  In the present invention, the conductive layer, the gold plating layer formed on the surface of the conductive layer and preventing corrosion of the conductive layer, and the conductive layer and the connected member are electrically connected via the gold plating layer. A suspension board having a connection region, wherein the connection portion is formed by dropping an alloy containing Au as a main component and having a melting point of 450 ° C. or lower in a molten state. There is provided a method for manufacturing a suspension board, comprising a connecting portion forming step of forming a connector.

  According to the present invention, by using an alloy containing Au as a main component and having a melting point of 450 ° C. or less, the alloy can be melted at a relatively low temperature, and a connection portion can be formed efficiently.

  In the present invention, the conductive layer, the gold plating layer formed on the surface of the conductive layer and preventing corrosion of the conductive layer, and the conductive layer and the connected member are electrically connected via the gold plating layer. A suspension board having a connection region having a connection portion, wherein the gold plating layer has a thickness of 0.5 μm or less.

  According to this invention, it can suppress that an intermetallic compound layer grows in the contact interface of a connection part and a gold plating layer by making thickness of a gold plating layer into a specific range or less. Thereby, for example, a suspension board having a ground terminal with low resistance and high durability can be obtained.

  In this invention, there exists an effect that the growth of the intermetallic compound layer produced in the contact interface of a connection part and a gold plating layer can be suppressed, and deterioration of a connection part can be prevented.

  Hereinafter, the suspension board and the manufacturing method thereof according to the present invention will be described in detail.

A. Suspension board First, the suspension board of the present invention will be described. The suspension board of the present invention can be roughly divided into three embodiments. Hereinafter, the suspension board of the present invention will be described by being divided into first to third embodiments.

1. First Embodiment First, a first embodiment of the suspension board of the present invention will be described. The suspension board according to this embodiment includes a conductive layer, a gold plating layer that is formed on the surface of the conductive layer and prevents corrosion of the conductive layer, and the conductive layer and the connected member via the gold plating layer. A suspension board having a connection region having electrical connection portions, wherein the connection portions are formed of an Au-Sn alloy mainly composed of Au. is there.

  According to this embodiment, the growth of the intermetallic compound layer can be suppressed at the contact interface between the connection portion and the gold plating layer by using the Au—Sn alloy containing Au as a main component. Thereby, for example, a suspension board having a ground terminal with low resistance and high durability can be obtained. Moreover, in this embodiment, it can suppress that Au of a gold plating layer diffuses into a connection part by using the alloy which has Au as a main component. This is presumably because Au in the gold plating layer is difficult to diffuse into the connection part because Au is previously contained in the alloy forming the connection part. In addition, the Au—Sn alloy containing Au as a main component can have a low melting point by appropriately selecting the composition. Therefore, there is an advantage that the connection portion can be easily formed.

  FIG. 1 is a schematic plan view showing an entire image of a general suspension board. The suspension board shown in FIG. 1 has a gimbal part 21 for mounting a magnetic head at one end, and a relay board connecting part 22 for connecting to the relay board at the other end. Furthermore, it has wiring 23 (wirings 23a to 23d) for connecting the gimbal part 21 and the relay board connecting part 22. The wirings 23a and 23b and the wirings 23c and 23d form a wiring pair, one for recording and the other for reproduction. The basic structure of the suspension board of this embodiment is basically the same.

  FIG. 2 is a schematic plan view for explaining an example of the suspension board according to the present embodiment. More specifically, FIG. 2 is a schematic plan view showing an enlarged front end portion on which a magnetic head slider or the like is mounted. The suspension board shown in FIG. 2 has a conductive layer 3 made of Cu (ground conductive layer 3a and wiring part 3b) on SUS as a metal support board 1 having spring properties through polyimide as an insulating layer 2. Has a formed structure. Note that the region A shown in FIG. 2 is an example of the ground terminal region in the present embodiment. A region B shown in FIG. 2 is an example of a gimbal region (device-suspension substrate connection region) in this embodiment.

  Next, the area A (ground terminal area) shown in FIG. 2 will be described. 3 is a cross-sectional view taken along the line XX of FIG. The suspension substrate shown in FIG. 3 is formed on the metal support substrate 1, the metal support substrate 1, the insulating layer 2 having the opening 6 through which the metal support substrate 1 is exposed, the insulating layer 2, and The conductive layer 3 (ground conductive layer 3a) disposed in the vicinity of the opening 6, the gold plating layer 4 formed on the surface of the conductive layer 3 to prevent corrosion of the conductive layer 3, and the opening of the insulating layer 2 6 includes a ground terminal region having a connection portion 5 (ground terminal 5a) for electrically connecting the conductive layer 3 and the metal supporting board 1 via the gold plating layer 4. This embodiment is characterized in that the connecting portion 5 is formed of an Au—Sn alloy mainly composed of Au.

Further, for example, when the connection portion is formed using a solder made of an Sn—Ag—Cu-based alloy and then left in a high temperature atmosphere for a long time, as shown in FIG. By diffusing to 5 (the ground terminal 5a), the intermetallic compound layer 7 grows at the contact interface between the gold plating layer 4 and the connection portion 5. There is a problem that a crack is generated in the connection portion 5 due to the influence. On the other hand, in this embodiment, the growth of the intermetallic compound layer can be suppressed and the increase of the resistance value can be suppressed by using the Au—Sn alloy mainly composed of Au. .
Hereinafter, the suspension board of the present embodiment will be described separately for the components of the suspension board and the configuration of the suspension board.

(1) Suspension board member The suspension board of this embodiment usually has a metal support board, an insulating layer, a conductive layer, a gold plating layer, a cover layer, and the like. Hereinafter, each member will be described in detail.

(I) Connection part The connection part used for this embodiment electrically connects a conductive layer and a to-be-connected member. Furthermore, in this embodiment, the connection portion is formed of an Au—Sn alloy mainly composed of Au. In this embodiment, “having Au as a main component” means that the component of Au is the largest among the components constituting the alloy. Considering that the Au—Sn alloy is usually a binary alloy of Au and Sn, the Au concentration of the Au—Sn alloy is usually 50% by weight or more.

  The Sn concentration of the Au—Sn alloy is not particularly limited as long as a connection part capable of suppressing the growth of the intermetallic compound layer can be obtained, but is usually less than 50% by weight, and in particular, 15% by weight to It is preferably within the range of 37% by weight. This is because if the Sn concentration is too high, it becomes difficult to suppress the growth of the intermetallic compound layer, and if the Sn concentration is too low, the melting point of the Au—Sn alloy increases. FIG. 5 is an alloy phase diagram of an Au—Sn alloy. As shown in FIG. 5, when the Sn concentration of the Au—Sn alloy is within the above range, an alloy having a sufficiently low melting point can be obtained. In addition, if the melting point of the Au—Sn alloy is low, there is an advantage that the formation of the connection portion is facilitated, as described in a suspension board manufacturing method described later. In particular, in this embodiment, it is preferable that the Au concentration of the Au—Sn alloy is 80 wt% and the Sn concentration is 20 wt%. This is because it corresponds to the eutectic point and the melting point can be 278 ° C.

  Although it does not specifically limit as resistance value of a connection part, For example, it is preferable that it is 5 ohms or less, especially 1 ohms or less, especially 0.5 ohms or less.

(Ii) Conductive layer and gold plating layer Next, the conductive layer and the gold plating layer used in this embodiment will be described. The conductive layer used in this embodiment is usually formed on an insulating layer. The gold plating layer used in this embodiment is formed on the surface of the conductive layer and prevents corrosion of the conductive layer.

  The material of the conductive layer is not particularly limited as long as it has good conductivity, and examples thereof include copper (Cu). The thickness of the conductive layer varies depending on the type of connection region, but is usually in the range of 6 μm to 18 μm, and preferably in the range of 8 μm to 12 μm.

  On the other hand, the gold plating layer is a layer provided to prevent the conductive layer from being exposed to the outside air. In this embodiment, since the connection portion is formed of an Au—Sn alloy containing Au as a main component, it is possible to effectively prevent Au from diffusing from the gold plating layer. Therefore, the thickness of the gold plating layer can be set relatively arbitrarily. The thickness of the gold plating layer is usually in the range of 0.1 μm to 4.0 μm, and preferably in the range of 0.2 μm to 3.0 μm. In this embodiment, a Ni plating layer may be provided between the conductive layer and the gold plating layer. The thickness of the Ni plating layer is the same as the thickness of the Ni plating layer in a general suspension board.

(Iii) Other members The suspension board of this embodiment usually has an insulating layer, a metal supporting board and a cover layer in addition to the above-mentioned members.

(Insulating layer)
The insulating layer used in this embodiment is formed between the metal support substrate and the conductive layer. The material of the insulating layer is not particularly limited as long as desired insulating properties can be exhibited, and examples thereof include polyimide (PI). The thickness of the insulating layer is usually in the range of 5 μm to 10 μm.

(Metal support substrate)
The metal support substrate used in this embodiment supports the above insulating layer and the like. The metal support substrate usually has appropriate springiness and conductivity. Examples of the material for the metal support substrate include SUS. In addition, the thickness of the metal support substrate is usually in the range of 10 μm to 20 μm, although it varies depending on the material of the metal support substrate.

(Cover layer)
The cover layer in this embodiment protects the exposed insulating layer and the like. Examples of the material for the cover layer include a polyimide resin and an epoxy resin. The material of the cover layer may be a photosensitive resin or a non-photosensitive resin. Although it does not specifically limit as thickness of a cover layer, Usually, it exists in the range of 5 micrometers-30 micrometers, and it is preferable to exist in the range of 5 micrometers-15 micrometers especially.

(2) Configuration of Suspension Board Next, the configuration of the suspension board of this embodiment will be described. The “connection region” in this embodiment can be roughly divided into a ground terminal region, a gimbal region, and a relay board connection region. Each configuration will be described in detail below.

(I) When the connection region is a ground terminal region When the connection region in this embodiment is a ground terminal region, the connection portion corresponds to a ground terminal, the connected member corresponds to a metal support substrate, and the conductive layer corresponds to the ground. Corresponds to the conductive layer. That is, when the connection region is a ground terminal region, the connection portion (ground terminal) connects the conductive layer (ground conductive layer) and the connected member (metal support substrate) through the opening of the insulating layer. Connect electrically. The ground conductive layer is usually called a ground pad or a ground line depending on its shape.

  In the present embodiment, as shown in FIG. 6A, the ground terminal 5a preferably has a convex shape. This is because the ground terminal having such a shape can be formed by, for example, a method of dropping a molten alloy into the opening, and this method can easily reduce the cost and simplify the process. Usually, when a molten alloy is dropped onto the opening, the molten alloy flows after landing, so that a convex shape having the landing point as a vertex is formed. In other words, the connection part (ground terminal) is preferably formed by dropping an Au—Sn alloy containing Au as a main component in a molten state. On the other hand, when the ground terminal is formed by plating, the shape of the ground terminal 5a has a recess near the center of the opening 6 as shown in FIG.

  The position where the ground terminal region is formed is not particularly limited as long as the ground terminal is a position where the ground conductive layer and the metal supporting board can be electrically connected. As shown in FIG. 2 described above, the magnetic head slider or the like may be provided at the tip of the suspension board, or as shown in FIG. 7, at a portion other than the tip of the suspension board. In FIG. 7, a line-shaped ground conductive layer 3a (ground line) is formed between a plurality of wiring portions 3b.

  The insulating layer has an opening for forming a ground terminal. In order to form the ground terminal, at least one of the ground conductive layer and the metal support substrate needs to further have an opening. In this embodiment, the ground conductive layer may have an opening, and the metal support substrate may have an opening. When the ground conductive layer has an opening, in other words, the conductive layer (ground conductive layer) has an opening, and the connection portion (ground terminal) is exposed from the openings of the conductive layer and the insulating layer. In this state, the support substrate and the conductive layer are electrically connected. Specifically, as shown in FIG. 8A, the ground terminal 5a includes the ground conductive layer 3a and the metal support substrate 1 exposed from the opening 6 of the insulating layer 2, and the ground conductive layer 3a. It is in an electrically connected state.

  On the other hand, when the metal support substrate has an opening, in other words, the metal support substrate has an opening, and the connection portion (ground terminal) is exposed from the opening of the metal support substrate and the insulating layer (ground). The conductive layer is electrically connected to the metal support substrate. Specifically, as shown in FIG. 8B, the ground terminal 5 a electrically connects the ground conductive layer 3 a exposed from the openings of the metal support substrate 1 and the insulating layer 2 and the metal support substrate 1. Connected. The gold plating layer 4 is formed on the exposed surface of the ground conductive layer 3a. Thus, when a metal support substrate has an opening part, it has the advantage that a connection part can be easily formed by the method of dripping the molten Au-Sn type alloy to an opening part. Furthermore, since this method drops the directly melted Au—Sn alloy on the gold plating layer having good wettability, it is possible to form a connection portion with little contact failure. On the other hand, when forming the suspension substrate as shown in FIG. 8A, there is a method of dropping a molten Au—Sn alloy on a metal support substrate such as SUS. At that time, the alloy is dropped. In order to remove oxides and the like on the surface of SUS immediately before, it is necessary to perform flux treatment and various types of cleaning. On the other hand, the above method melts and drops the Au-Sn alloy having good wettability with the target metal (gold plating layer), so there is no need to perform flux treatment or various types of cleaning, and productivity is improved. It has the advantage that it can be improved.

  In the present embodiment, it is preferable that the ground terminal is formed only inside the region surrounded by the end of the opening of the insulating layer. This is because the ground conductive layer disposed in the vicinity of the opening can be reduced in size, and space saving and weight reduction can be achieved. In addition, if the weight can be reduced, the metal support substrate can be thinned. Specifically, as illustrated in FIG. 9A, the ground conductive layer 3 a has an opening, and the ground terminal 5 a is only inside the region surrounded by the end of the opening 6 of the insulating layer 2. Can be mentioned. In this embodiment, the ground conductive layer 3 a may have an opening smaller than the opening 6 of the insulating layer 2 as shown in FIG. 9B. Similarly, as shown in FIG. 9C, the metal support substrate 1 has an opening, and the ground terminal 5 a is formed only inside the region surrounded by the end of the opening 6 of the insulating layer 2. Can be mentioned. In the present embodiment, the metal support substrate 1 may have an opening smaller than the opening 6 of the insulating layer 2 as shown in FIG. Further, from the viewpoint of improving the bonding reliability, it is preferable that the connection portion is formed so as to fill the opening of the insulating layer. On the other hand, from the viewpoint of weight reduction, the connection portion may be formed so as not to partially fill the opening of the insulating layer. As a method of forming such a connection portion, for example, as described in “B. Suspension substrate manufacturing method” described later, when the alloy is molten and dropped into the opening of the insulating layer, the molten alloy A method of making the diameter smaller than the diameter of the opening of the insulating layer can be exemplified.

  Further, the shape of the opening of the insulating layer is not particularly limited as long as the connecting portion is a shape that can electrically connect the metal support substrate and the ground conductive layer. An arbitrary polygonal shape such as a quadrangle and a pentagon, a comb shape, a cross shape, a rod shape, and the like. In addition, as a shape of the opening part of an insulating layer, circular shape is common, and the diameter is in the range of 50 micrometers-300 micrometers normally in that case. The same applies to the ground conductive layer or the opening of the metal support substrate. In the present embodiment, the ground conductive layer or the metal support substrate may have an opening smaller than the opening of the insulating layer, or have an opening having the same size as the opening of the insulating layer. Alternatively, the opening may be larger than the opening of the insulating layer.

  The ground conductive layer used in this embodiment is formed on the insulating layer and disposed in the vicinity of the opening of the insulating layer. The “near the opening” means a position where the opening can be substantially grounded via the ground terminal. For example, it refers to a region within a range of 50 μm from the end of the opening of the insulating layer.

  The shape of the ground conductive layer is not particularly limited as long as it can be electrically connected to the metal support substrate through the ground terminal, and can be set to an arbitrary shape. Usually, the ground conductive layer is formed so as to surround the opening of the insulating layer in plan view. For example, as shown in FIG. 10, the ground conductive layer 3a is formed so as to surround the opening 6 formed in the insulating layer 2 in plan view.

  As described above, the ground conductive layer is formed so as to surround the opening in a plan view and, as will be described later, a low melting point alloy is melted and dropped into the opening. Therefore, when forming the ground terminal, there is no escape of air during dripping, and an air pool is generated. As a result, there is a possibility that the contact between the ground terminal and the metal supporting board becomes insufficient. Specifically, as shown in FIG. 11, the air pool 8 is generated, and there is a possibility that the contact between the ground terminal 5 a and the metal supporting board 1 becomes insufficient.

  Therefore, in the above case, it is preferable that at least one of the ground conductive layer and the insulating layer has an air vent portion that suppresses air accumulation generated when the ground terminal is formed. This is because the contact area between the ground terminal and the metal support substrate can be sufficiently increased by suppressing the occurrence of air accumulation. As an example of the ground conductive layer having an air vent portion, for example, as shown in FIG. 12A, a ground conductive layer 3a having an air vent portion 9 can be cited. In the present embodiment, only the ground conductive layer 3a may have the air vent portion 9 (FIG. 12A), and both the ground conductive layer 3a and the insulating layer 2 have the air vent portion 9. Is also good (FIG. 12B). When the ground conductive layer is made of copper, an air vent portion of about 20 μm to 50 μm can be provided. Further, the ground conductive layer or the insulating layer may have a plurality of air vent portions.

In the present embodiment, the ground conductive layer may not be formed so as to surround the opening of the insulating layer in plan view. Specifically, as shown in FIG. 13A, the ground conductive layer 3 a may be simply formed in the vicinity of the opening 6 of the insulating layer 2. That is, the shape of the ground conductive layer in the vicinity of the opening may be a line. Even in such a case, as shown in FIG. 13B, the ground terminal 5 a can sufficiently conduct the ground conductive layer 3 a and the metal support substrate 1. In this case, it is not necessary to provide the above-described air vent portion in the ground conductive layer or the insulating layer. Further, as shown in FIG. 14A, a plurality of line-shaped ground conductive layers 3 a may be formed in the vicinity of the opening 6 of the insulating layer 2. Thereby, joining reliability can be improved. On the other hand, as shown in FIG. 14B, the line-shaped ground conductive layer 3a may be formed so as to be in contact with the opening 6 of the insulating layer 2 at the side in a plan view. Thereby, the freedom degree of design of the position of an opening part can be improved.

  In this embodiment, as will be described later, a ground terminal that contacts the metal support substrate and the ground conductive layer can be formed by dropping the molten alloy into the opening of the insulating layer in a molten state. In this case, the ground conductive layer can be reduced in size and space and weight can be reduced as compared with a conventional method of forming a ground terminal by plating or the like. From the viewpoint of preventing the deterioration of the insulating layer, it is preferable to form the ground conductive layer so that the ground terminal and the insulating layer do not come into contact with each other. Here, as shown in FIG. 15, the distance between the end of the ground conductive layer 3a on the opening 6 side and the end on the side away from the opening 6 is a distance C. In the present embodiment, when the ground terminal is formed using the above method, the ground conductive layer can be downsized as compared with the conventional plating method or the like. In this case, the distance C can be set to 75 μm or less, particularly 50 μm or less.

  Furthermore, in this embodiment, as will be described later, when the alloy is melted and dropped into the opening of the insulating layer, the diameter of the molten alloy can be made smaller than the diameter of the opening of the insulating layer. preferable. This is because the ground conductive layer disposed in the vicinity of the opening can be further reduced in size. In this case, the distance C can be set to 40 μm or less, particularly 30 μm or less. On the other hand, the distance C is usually 20 μm or more from the viewpoint of securing the mechanical strength of the ground conductive layer.

  The suspension board of this embodiment usually has a cover layer on the insulating layer. In this embodiment, as shown in FIG. 16A, the cover layer 11 may be formed so as to cover a part of the ground conductive layer 3a, and as shown in FIG. The cover layer 11 may be formed so as not to cover the ground conductive layer 3a and to be adjacent to the ground conductive layer 3a, and as shown in FIG. The cover layer 11 may be formed at a predetermined interval from the conductive layer 3a.

  FIG. 17 is a schematic plan view illustrating the structure around the ground terminal in this embodiment. FIG. 17A shows an NSMD type ground terminal 5a in which the cover layer 11 does not cover the ground conductive layer 3a, and the ground terminal 5a is formed along the opening of the ground conductive layer 3a. FIG. 17B shows an SMD type ground terminal 5a in which the cover layer 11 covers a part of the ground conductive layer 3a, and includes the air vent portion 9, the cover layer 11, and the insulating layer cover layer 11 ′. . In this case, the ground terminal 5 a is formed along the opening of the cover layer 11. FIG. 17C shows an SMD type ground terminal 5a in which the cover layer 11 covers a part of the ground conductive layer 3a, and has a line-shaped ground conductive layer 3a. In this case, the ground terminal 5 a is formed along the opening of the cover layer 11. FIG. 17D shows an NSMD type ground terminal 5 a in which the cover layer 11 does not cover a part of the ground conductive layer 3 a, and has an air vent portion 9. In this case, the ground terminal 5a is formed along the opening of the ground conductive layer 3a.

(Ii) When the connection region is a gimbal region When the connection region in this embodiment is a gimbal region, the connected member corresponds to an element, and the conductive layer corresponds to a wiring portion. That is, when the connection region is a gimbal region, the connection part electrically connects the conductive layer and the element that is the member to be connected. When electrical connection is made in the gimbal region, the suspension board includes elements such as a magnetic head slider in addition to the suspension board. Even in such a case, in this embodiment, it will be called a suspension board. That is, when the connection region is a gimbal region, the suspension board of this embodiment includes a configuration including elements.

  FIG. 18 is a schematic plan view for explaining an example of the suspension board of the present embodiment. More specifically, FIG. 18 is a schematic plan view showing an enlarged tip end portion on which an element such as a magnetic head slider is mounted. The suspension board shown in FIG. 18 has a structure in which a conductive layer 3 (wiring portion 3b) made of Cu is formed on SUS as a metal support board 1 having spring properties through polyimide as an insulating layer 2. have. Further, the connection part 5 electrically connects the conductive layer 3 (wiring part 3 b) and the element 20 via the gold plating layer 4.

  19 is a YY cross-sectional view of FIG. The suspension board shown in FIG. 19 includes a metal supporting board 1, an insulating layer 2 formed on the metal supporting board 1, a conductive layer 3 (wiring part 3b) formed on the insulating layer 2, and a conductive layer 3 A gimbal region having a gold plating layer 4 for preventing corrosion of the conductive layer 3 and a connection portion 5 for electrically connecting the conductive layer 3 and the element 20 via the gold plating layer 4. It is provided. This embodiment is characterized in that the connecting portion 5 is formed of an Au—Sn alloy mainly composed of Au.

  Specific examples of the element used in this embodiment include a magnetic head slider and an actuator. The actuator may have a magnetic head or may not have a magnetic head. Examples of the method for forming the connection portion in the gimbal region include a method of dropping a molten alloy (solder) (Solder Bump Bonding, SBB).

(Iii) When the connection area is a relay board connection area When the connection area in this embodiment is a relay board connection area, the connected member corresponds to the terminal part of the relay board, and the conductive layer corresponds to the terminal part of the suspension board. Applicable. That is, when the connection region is a relay board connection region, the connection part electrically connects the conductive layer and the terminal part of the relay board that is the connected member. When electrical connection is performed in the relay board connection region, the suspension board includes the relay board and other members in addition to the suspension board. Even in such a case, in this embodiment, it will be called a suspension board. That is, when the connection area is a relay board connection area, the suspension board of this embodiment includes a configuration including the relay board and other members.

  FIG. 20 is a schematic cross-sectional view for explaining an example of the suspension board of the present embodiment, and more specifically, a schematic cross-sectional view in which a relay board connection region is enlarged. In FIG. 20, the relay substrate 30 includes an insulating layer 32, a terminal portion 33, a gold plating layer 34, and a cover layer 35. On the other hand, the suspension board 12 has a flying lead 3c and a gold plating layer 4 covering the periphery thereof. Here, the connection part 5 electrically connects the flying lead 3 c of the suspension board 12 and the terminal part 33 of the relay board 30 via the gold plating layers 4 and 34. On the other hand, as a connection method in the relay board region, there is a method of connecting the suspension board and the relay board at a right angle. Specifically, as shown in FIG. 21, there is a method of connecting the conductive layer 3 of the suspension board 12 and the terminal portion 33 of the relay board so as to be at right angles.

2. Second Embodiment Next, a second embodiment of the suspension board of this embodiment will be described. The suspension board according to this embodiment includes a conductive layer, a gold plating layer that is formed on the surface of the conductive layer and prevents corrosion of the conductive layer, and the conductive layer and the connected member via the gold plating layer. A suspension board having a connection region having electrical connection, wherein the connection portion is made of an alloy containing Au as a main component and having a melting point of 450 ° C. or lower. Is.

  According to this embodiment, it is possible to suppress the growth of the intermetallic compound layer at the contact interface between the connection portion and the gold plating layer by using an alloy containing Au as a main component and a melting point of 450 ° C. or less. . Thereby, for example, a suspension board having a ground terminal with low resistance and high durability can be obtained. Moreover, in this embodiment, it can suppress that Au of a gold plating layer diffuses into a connection part by using the alloy which has Au as a main component. This is presumably because Au in the gold plating layer is difficult to diffuse into the connection part because Au is previously contained in the alloy forming the connection part. Moreover, since the alloy used in this embodiment has a low melting point, it has an advantage that the connection portion can be easily formed.

  The suspension board of this embodiment is described in “1. First embodiment” above, except that the connection portion is made of an alloy having Au as a main component and a melting point of 450 ° C. or lower. Since the contents are the same as those described above, description thereof is omitted here. Hereinafter, the alloy used in this embodiment will be described.

  In this embodiment, the connection portion is formed of an alloy containing Au as a main component and a melting point of 450 ° C. or lower. In this embodiment, “having Au as a main component” means that the component of Au is the largest among the components constituting the alloy. The alloy used in the embodiment may be a two-component system or a three-component system or more as long as it has Au as a main component and a melting point of 450 ° C. or lower. The Au concentration in the alloy is preferably selected as appropriate so that the melting point of the alloy is lowered.

  The melting point of the alloy used in this embodiment is usually 450 ° C. or lower, preferably 350 ° C. or lower, particularly preferably 250 ° C. or lower. This is because if the melting point of the alloy is low, the metal can be easily melted and the connection portion can be formed easily.

  In this embodiment, the “melting point” refers to the temperature at which a solid phase substance maintains equilibrium with the liquid phase under a constant pressure, and is also referred to as the melting point. In the case of a eutectic composition (a mixture of two or more crystals crystallized simultaneously from a liquid containing two or more components) with two or more components, the melting point coincides with the freezing point (the temperature at which the liquid solidifies). Also, in the case of an alloy that is not a eutectic composition composed of two or more components coexisting in equilibrium, the relationship between the liquid or solid composition composed of two or more components coexisting in equilibrium and the temperature, that is, the melting point When the temperature (melting point) is taken on the vertical axis and the composition (ratio of components) is taken on the horizontal axis, the temperature at which the liquid phase and the solid phase are kept in equilibrium is drawn. A liquidus is obtained, and the liquidus point here is the melting point. Further, the lower limit of the melting point of the alloy is not particularly limited as long as it is solid at normal temperature (25 ° C.), but is usually 100 ° C. or higher.

  The melting point of the metal can be measured by differential thermal analysis (DTA) or differential scanning calorimetry (DSC) according to JIS Z3198-1. Examples of the thermal analyzer include DSC8230 and TG8120 manufactured by Rigaku Corporation.

  The type of the alloy is not particularly limited as long as it is mainly composed of Au and has a melting point of 450 ° C. or lower. However, an Au—Bi alloy, an Au—Cd alloy, an Au—Ga alloy, Au-Ge alloy, Au-Hg alloy, Au-In alloy, Au-Na alloy, Au-Pb alloy, Au-Sb alloy, Au-Si alloy, Au-Sn alloy, Au- Te alloy, Au-Ti alloy, etc. can be mentioned. In addition, the alloy shown here is not limited to a two-component system, but shows a minimum component, and may be a ternary or higher alloy. However, from the viewpoint of easily determining the behavior of the melting point, the alloy is preferably a binary system.

  In this embodiment, it is preferable that the alloy does not contain lead. This is because the environmental load can be reduced. Specifically, the alloy is preferably an Au—Bi alloy, an Au—In alloy, an Au—Sn alloy, or an Au—Sb alloy. In particular, in the present embodiment, the alloy is preferably an Au—Sn alloy. This is because an alloy having a low melting point can be obtained.

3. Third Embodiment Next, a third embodiment of the suspension board of this embodiment will be described. The suspension board according to this embodiment includes a conductive layer, a gold plating layer that is formed on the surface of the conductive layer and prevents corrosion of the conductive layer, and the conductive layer and the connected member via the gold plating layer. A suspension board having a connection region having an electrical connection portion, wherein the gold plating layer has a thickness of 0.5 μm or less.

  According to this embodiment, it is possible to suppress the growth of the intermetallic compound layer at the contact interface between the connection portion and the gold plating layer by setting the thickness of the gold plating layer to a specific range or less. Thereby, for example, a suspension board having a ground terminal with low resistance and high durability can be obtained.

  The thickness of the gold plating layer is usually 0.5 μm or less, preferably 0.4 μm or less, particularly preferably 0.3 μm or less. This is because, within the above range, Au can be further suppressed from diffusing into the connecting portion and growing the intermetallic compound layer. On the other hand, the thickness of the plating layer is, for example, 0.05 μm or more, preferably 0.1 μm or more. This is because the conductive layer can be protected from corrosion within the above range.

  Moreover, it is preferable that the connection part used for this embodiment is formed with the alloy. Especially, in this embodiment, it is preferable that the connection part is formed of an Au—Sn alloy containing Au as a main component or an alloy containing Au as a main component and having a melting point of 450 ° C. or less. Since these alloys are the same as the contents described in “1. First embodiment” and “2. Second embodiment” described above, description thereof is omitted here. In addition, the “connection region” in the present embodiment is preferably a ground terminal region, a gimbal region, or a relay board connection region, for example. Since these areas are the same as the contents described in “1. First embodiment” described above, description thereof is omitted here.

B. Next, a method for manufacturing a suspension board according to the present invention will be described. The suspension board manufacturing method of the present invention can be roughly divided into two embodiments. Hereinafter, a method for manufacturing a suspension board according to the present invention will be described by dividing it into a first embodiment and a second embodiment.

1. First Embodiment First, a first embodiment of the suspension board manufacturing method of the present invention will be described. The suspension board manufacturing method of this embodiment includes a conductive layer, a gold plating layer formed on the surface of the conductive layer to prevent corrosion of the conductive layer, the conductive layer and the connected member, and the gold plating layer. A suspension board having a connection region that is electrically connected via an Au-Sn-based alloy containing Au as a main component by dropping in a molten state. It has the connection part formation process which forms a connection part, It is characterized by the above-mentioned.

  According to this embodiment, by using an Au—Sn alloy containing Au as a main component, the alloy can be melted at a relatively low temperature, and a connection portion can be formed efficiently.

  In particular, when the ground terminal is formed by the suspension board manufacturing method of this embodiment, the following advantages are obtained. That is, when the ground terminal is formed by the conventional plating method, the step of laminating the dry film, the step of exposing the dry film, the step of developing the dry film after exposure, the SUS surface of the opening forming the ground terminal Many processes such as a process of removing the oxide film, a process of plating the opening, and a process of peeling off the dry film are necessary. Furthermore, in order to plate the minute openings, it is necessary to mask many other areas, which is a very inefficient operation. On the other hand, in this embodiment, the ground terminal can be formed only by the step of dripping the molten alloy and the pretreatment step of the metal support substrate, which is performed as necessary, thereby reducing costs and steps. Can be simplified. Further, for example, when the shape of the opening is complicated, if the ground terminal is formed by a conventional plating method, the obtained ground terminal becomes brittle and may not have sufficient strength. On the other hand, in this embodiment, since the metal is dropped in a molten state, there is an advantage that the obtained ground terminal does not become brittle as in the plating method. Moreover, according to this embodiment, a ground terminal can be formed with respect to an opening having an arbitrary shape.

  On the other hand, when the terminal part with the relay board is formed by the suspension board manufacturing method of the present embodiment, the following advantages are obtained. That is, when the terminal portion with the relay substrate is formed by the conventional paste method, it is necessary to perform reflow after the paste is applied. Therefore, the suspension substrate (substrate forming member) before the terminal portion with the relay substrate is formed. ) Had to have some heat resistance. On the other hand, in the present embodiment, heating is required to melt the alloy, but heating is not required in principle for the substrate forming member. Therefore, for example, it is possible to prevent deterioration of the metal interface adhesion strength between polyimide and the like used as an insulating layer and the terminal portion, and to suppress diffusion of the underlying Cu to the gold plating of the terminal portion.

  Next, a method for manufacturing the suspension board of this embodiment will be described with reference to the drawings. FIG. 22 is a process diagram showing an example of a manufacturing method of the suspension board according to the present embodiment. More specifically, a case where a connection portion (ground terminal) is formed in the ground terminal region will be described. The suspension board manufacturing method shown in FIG. 22 is formed on the metal support board 1, the insulating layer 2 formed on the metal support board 1 and having the opening 6 through which the metal support board 1 is exposed, and the insulating layer 2. And a conductive layer 3 (ground conductive layer 3a) disposed in the vicinity of the opening 6, and a gold plating layer 4 formed on the surface of the conductive layer 3 to prevent corrosion of the conductive layer. Member 10 is prepared (FIG. 22 (a)), and then the molten alloy 42 is quantitatively dropped into the opening 6 using the dropping device 41 (FIG. 22 (b)). 1 and a connection portion forming step of forming a connection portion 5 (ground terminal 5a) in contact with the ground conductive layer 3a (FIG. 22C).

  The “connection region” in this embodiment can be roughly divided into a ground terminal region, a gimbal region, and a relay board connection region. In particular, in this embodiment, the connection region is preferably a ground terminal region. Since the connection region is the same as that described in “A. Suspension board”, description thereof is omitted here.

(1) Connection part formation process The connection part formation process in this embodiment is a process which forms a connection part by dripping the Au-Sn type alloy which has Au as a main component in the molten state. In addition, about the alloy used for this embodiment, it is the same as that of the content described in said "A. suspension board | substrate 1. 1st embodiment."

  The dropping method for dropping the alloy in a molten state is not particularly limited. For example, an alloy ball having a predetermined diameter is used, and the alloy ball is sequentially melted and dropped. An example is a method in which an alloy is stored in a molten state in a container, and quantitatively dropped from the container little by little.

  Especially, in this embodiment, it is preferable that the dropping method is a method in which alloy balls having a predetermined diameter are used and the alloy balls are sequentially melted and dropped. This is because the amount of molten alloy dropped can be freely adjusted by appropriately selecting the diameter of the alloy balls as the raw material. Although it does not specifically limit as a diameter of an alloy ball, Usually, it exists in the range of 60 micrometers-250 micrometers. In this embodiment, it is preferable to determine the diameter of the alloy ball in consideration of the size of the portion where the molten alloy is dropped.

As a dropping device that performs dropping using an alloy ball, for example, a raw material supply unit that supplies the alloy ball, a melting unit that melts the supplied alloy ball, and a dropping unit that drops the molten alloy ball are included. The thing etc. can be mentioned. In such an apparatus, first, an alloy ball as a raw material is filled in the raw material supply unit, and thereafter, the alloy ball is sequentially supplied from the raw material supply unit to the melting unit to melt the supplied alloy ball. Examples of the melting method include a YAG laser. Thereafter, molten alloy balls are dropped from the dropping portion. Examples of the method of dropping the molten alloy ball include a method of extruding a molten alloy ball with an inert gas such as N ₂ . Such dropping apparatus, specifically, PAC-TECH PACKAGING TECHNOLOGIES Gmbh Co., can be mentioned SB ² -jet like.

  In the present embodiment, a predetermined amount of molten alloy necessary for forming the connection portion may be dropped at once, or may be dropped at a plurality of times. When dripping at once, there is an advantage that the number of steps is small, and when dropping at a plurality of times, there is an advantage that the occurrence of air accumulation can be suppressed by dripping little by little.

  Further, in this embodiment, when forming the ground terminal, when the alloy is dropped in a molten state, the diameter of the molten alloy is set so that contact with the end of the opening of the insulating layer does not occur. It is preferable to set. Specifically, when the alloy is dropped in a molten state, the diameter of the molten alloy is preferably smaller than the diameter of the opening of the insulating layer. This is because the molten alloy can be landed more reliably. Thereby, generation | occurrence | production of an air pool can be suppressed, the joining area of a metal support substrate and a ground terminal increases, and joining reliability improves. Furthermore, by improving the landing accuracy, the ground conductive layer disposed in the vicinity of the opening of the insulating layer can be reduced in size, and space saving and weight reduction can be achieved. In addition, if the weight can be reduced, the metal support substrate can be thinned.

  Specifically, as shown in FIG. 23A, when the molten alloy 42 is dropped into the opening 6 of the insulating layer 2 using the dropping device 41, the horizontal diameter 42x of the molten alloy 42 is set. The diameter of the opening 6 is made smaller. As a result, as shown in FIG. 23B, the molten alloy 42 is easily landed on the surface of the metal support substrate 1 exposed from the opening 6. Further, as shown in FIG. 23C, the obtained ground terminal 5 a is formed only inside the region surrounded by the end of the opening 6 of the insulating layer 2. The obtained ground terminal is the same as the content described in “A. Suspension board”, and a description thereof is omitted here.

  The diameter of the molten alloy mentioned above refers to the size in the horizontal direction when the molten alloy dropped from a dropping device or the like enters the opening of the insulating layer (reference numeral 42x in FIG. 23A). On the other hand, the diameter of the opening of the insulating layer differs depending on the shape of the opening. For example, when the shape of the opening is a circle, the diameter is the diameter. In this embodiment, the diameter of the molten alloy is preferably smaller than the diameter of the opening of the insulating layer, for example, by 10 μm or more, and particularly preferably within a range of 15 μm to 30 μm. Although it does not specifically limit as a diameter of the molten alloy, Usually, it exists in the range of 40 micrometers-150 micrometers, and it is preferable to exist in the range of 60 micrometers-100 micrometers especially. On the other hand, the diameter of the opening of the insulating layer is the same as that described in “A. Suspension substrate”.

  Moreover, if the diameter of the molten alloy is too small, the formed ground terminal may not be able to sufficiently connect the metal support substrate and the ground conductive layer. Therefore, when forming the ground terminal by one drop, it is preferable to set the diameter of the molten alloy so that the metal support substrate and the ground conductive layer can be sufficiently connected. At this time, it is preferable to consider the relationship between the volume of the molten alloy and the area of the opening of the insulating layer. On the other hand, even when the diameter of the molten alloy is too small, as described above, it is possible to sufficiently connect the metal support substrate and the ground conductive layer by dropping in a plurality of times. .

  Further, in the suspension board shown in FIG. 8A described above, since the ground conductive layer 3a has an opening, a molten alloy is formed on the exposed surface of the metal support board 1 when the connection part is formed. Dripping. In this case, for example, when SUS is used as the metal support substrate, it is preferable to perform a pretreatment to remove impurities present on the SUS surface before dropping. Specific examples of the pretreatment include flux treatment, pickling treatment, plasma washing treatment, and degreasing treatment. On the other hand, when the suspension board shown in FIG. 8 (b) described above is manufactured, since the molten alloy is directly dropped onto the gold plating layer having good wettability, a ground terminal with few contact failures can be formed. Has the advantage.

  Moreover, in this embodiment, the connection part may be formed by arranging the alloy ball as a raw material in a position where the connection part is formed in advance and melting the alloy ball.

(2) Other Steps In the present embodiment, the same steps as the respective steps in a general suspension board manufacturing method can be adopted except for the connection portion forming step.

2. Second Embodiment Next, a second embodiment of the suspension board manufacturing method of the present invention will be described. The suspension board manufacturing method of this embodiment includes a conductive layer, a gold plating layer formed on the surface of the conductive layer to prevent corrosion of the conductive layer, the conductive layer and the connected member, and the gold plating layer. A suspension board having a connection region electrically connected via a wire, and dropping a molten alloy mainly composed of Au and having a melting point of 450 ° C. or lower. And a connecting part forming step for forming the connecting part.

  According to this embodiment, by using an alloy containing Au as a main component and having a melting point of 450 ° C. or lower, the alloy can be melted at a relatively low temperature, and a connection portion can be formed efficiently.

  The manufacturing method of the suspension board of the present embodiment is the same as that described in “1. First embodiment” except that an alloy containing Au as a main component and having a melting point of 450 ° C. or lower is used. Since there is, explanation here is omitted. Further, the alloy used in this embodiment is the same as that described in “A. Suspension board 1. First embodiment”, and therefore the description thereof is omitted here.

  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 1]
(Production of substrate forming member)
Prepare a laminated body in which SUS304 (metal support substrate) with a thickness of 20 μm, a polyimide layer (insulating layer) with a thickness of 10 μm, and an electrolytic copper foil (conductive layer) with a thickness of 18 μm are laminated in this order. The chemical etching described below was performed. First, the region of the conductive layer forming the ground terminal is processed into a shape having an outer diameter of 250 μm and an inner diameter (opening diameter) of 100 μm by chemical etching, and then SUS is chemically etched to define the outer shape of the suspension board, and then Chemical etching was performed on the polyimide layer to form an opening having a diameter of 100 μm. Thereafter, Ni was plated by electrolysis to a thickness of about 0.2 μm, and Au was plated by electrolysis to a thickness of about 0.5 μm on the surface of the conductive layer forming the ground terminal. This obtained the member for board | substrate formation.

(Formation of connecting part)
Next, in order to activate the SUS surface in the opening, treatment (pickling) was performed using phosphoric acid as a pretreatment. Thereafter, Au80-Sn20 (Au80 wt%, Sn wt%) having a diameter of 0.1mm made of an alloy, providing a solder ball, using Pac-Tech Co. ^SB 2 -jet, while melting the solder ball opening By dropping on the part, a connection part (ground terminal) was formed, and a suspension board was obtained.

[Comparative Example 1]
A suspension board was obtained in the same manner as in Example 1 except that a Sn-3.0Ag-0.5Cu alloy was used instead of the Au80-Sn20 alloy.

[Evaluation 1]
Using the suspension substrates obtained in Example 1 and Comparative Example 1, a high-temperature treatment test was performed, and changes in the appearance and element distribution of the connection part before and after the evaluation were evaluated. The high temperature treatment test was conducted by leaving it at 125 ° C. for 144 hours.

  FIG. 24 is a plan view showing the appearance of the connection part before and after the high-temperature treatment test. In Comparative Example 1, it can be seen that the intermetallic compound layer has grown at the contact interface between the connecting portion and the gold plating layer after the high temperature treatment test. Furthermore, it was confirmed that a crack occurred in the center of the connection portion. On the other hand, in Example 1, the growth of the intermetallic compound layer was not recognized even after the high temperature treatment test.

  FIG. 25 is a cross-sectional view showing the appearance of the connection part before and after the high-temperature treatment test. In Comparative Example 1, it was confirmed that an intermetallic compound layer was already formed before the high temperature treatment test. Furthermore, after the high temperature treatment test, it was confirmed that the gold plating layer in contact with the connection portion had disappeared. This is presumably because all of the gold plating layer has diffused into the connecting portion. Moreover, it was confirmed that the shape of the connection part changed remarkably before and after the high temperature treatment test. This is considered to be the influence of stress due to the growth of the intermetallic compound layer. This shape change may adversely affect the bondability between the connection portion and the metal support substrate. On the other hand, in Example 1, no growth of the intermetallic compound layer was observed even after the high temperature treatment test, and no change in the shape of the connecting portion was observed.

  FIG. 26 shows the result of EDX measurement of the connection portion of the suspension board of Comparative Example 1 before and after the high temperature treatment test. As a result of EDX measurement, it was confirmed that all Au of the gold plating layer was diffused in the connection part after the high temperature treatment test. On the other hand, FIG. 27 shows the result of EDX measurement of the connection part of the suspension board of Example 1 before and after the high temperature treatment test. As a result of the EDX measurement, Au was not diffused from the gold plating layer even after the high temperature treatment test.

  Further, the suspension substrate obtained in Example 1 and Comparative Example 1 was used to evaluate the temporal change in the resistance value of the ground terminal in the high-temperature treatment test. The results are shown in Table 1. FIG. 28 is a graph comparing the average resistance values (AVG) of Example 1 and Comparative Example 1.

  As shown in Table 1 and FIG. 28, it was confirmed that in Comparative Example 1, the resistance value increased with time. On the other hand, in Example 1, even after the high temperature treatment test for 144 hours, there was almost no difference from the resistance value before the high temperature treatment test.

[Example 2]
A suspension board was obtained in the same manner as in Comparative Example 1 except that the thickness of the gold plating layer was changed to 0.2 μm.

[Comparative Example 2]
A suspension board was obtained in the same manner as in Comparative Example 1 except that the thickness of the gold plating layer was changed to 1.0 μm.

[Evaluation 2]
Using the suspension boards obtained in Example 2 and Comparative Example 2, a high-temperature treatment test was performed to evaluate changes in the appearance of the connection portion over time. The high temperature treatment test was carried out by leaving it at 125 ° C. and confirming the state after 0 hours, 12 hours, 24 hours and 144 hours.

  FIG. 29 is a plan view showing the appearance of the connection part in the high-temperature treatment test. In Comparative Example 2, formation of the intermetallic compound layer was confirmed after 12 hours, and it was confirmed that the intermetallic compound layer was further grown after 144 hours. On the other hand, in Example 2, although the formation of the intermetallic compound layer was confirmed after 12 hours, it was confirmed that the growth of the intermetallic compound layer was suppressed even after 144 hours.

It is a schematic plan view which shows the whole image of a general suspension board. It is a schematic plan view explaining an example of the suspension board of the present invention. It is XX sectional drawing of FIG. It is a schematic sectional drawing explaining an example of the conventional suspension board. It is an alloy phase diagram of an Au-Sn type alloy. It is a schematic sectional drawing explaining an example of the suspension board of this invention. It is a schematic plan view explaining an example of the position which forms a ground terminal area. It is a schematic sectional drawing explaining the suspension board of this invention. It is a schematic sectional drawing explaining the suspension board of this invention. It is a schematic plan view explaining an example of the suspension board of the present invention. It is a schematic sectional drawing explaining an example of the suspension board of this invention. It is a schematic plan view explaining the suspension board of the present invention. It is explanatory drawing explaining an example of the suspension board of this invention. It is a schematic plan view explaining the suspension board of the present invention. It is a schematic sectional drawing explaining an example of the suspension board of this invention. It is a schematic sectional drawing explaining the suspension board of this invention. It is a schematic plan view explaining the suspension board of the present invention. It is a schematic plan view explaining an example of the suspension board of the present invention. It is YY sectional drawing of FIG. It is a schematic sectional drawing explaining an example of the suspension board of this invention. It is a schematic sectional drawing explaining an example of the suspension board of this invention. It is a schematic sectional drawing explaining an example of the manufacturing method of the suspension board of this invention. It is a schematic sectional drawing explaining an example of the manufacturing method of the suspension board of this invention. 2 is a plan photograph showing the results of Example 1 and Comparative Example 1. 2 is a cross-sectional photograph showing the results of Example 1 and Comparative Example 1. It is a cross-sectional photograph which shows the result of the EDX measurement of the comparative example 1. It is a cross-sectional photograph which shows the result of the EDX measurement of Example 1. It is a graph which shows the result of resistance value (ohm) of the ground terminal of Example 1 and Comparative Example 1. 6 is a plan photograph showing the results of Example 2 and Comparative Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Metal support board 2 ... Insulating layer 3 ... Conductive layer 3a ... Ground conductive layer 3b ... Wiring layer 3c ... Flying lead 4 ... Gold plating layer 5 ... Connection part 5a ... Ground terminal 6 ... Opening part 7 ... Intermetallic compound layer DESCRIPTION OF SYMBOLS 8 ... Air pool 9 ... Air vent part 10 ... Board | substrate formation member 11 ... Cover layer 12 ... Suspension board

Claims (13)

A conductive layer; a gold plating layer formed on the surface of the conductive layer to prevent corrosion of the conductive layer; and a connection portion for electrically connecting the conductive layer and the connected member via the gold plating layer. A suspension board having a connection region having
The suspension board, wherein the connection portion is formed of an Au-Sn alloy mainly composed of Au.   The suspension board according to claim 1, wherein the Sn concentration of the Au-Sn alloy is in the range of 15 wt% to 37 wt%.   The suspension board according to claim 1 or 2, wherein the Au-Sn alloy has an Au concentration of 80 wt% and an Sn concentration of 20 wt%. A conductive layer; a gold plating layer formed on the surface of the conductive layer to prevent corrosion of the conductive layer; and a connection portion for electrically connecting the conductive layer and the connected member via the gold plating layer. A suspension board having a connection region having
The suspension board is characterized in that the connection portion is made of an alloy having Au as a main component and a melting point of 450 ° C. or lower.   The connection region is a ground terminal region, and the connection part electrically connects the conductive layer and the metal supporting board as the connected member through an opening of an insulating layer. The suspension board according to any one of claims 1 to 4.   The conductive layer has an opening, and the connection portion electrically connects the conductive layer and the metal support substrate exposed from the openings of the conductive layer and the insulating layer. The suspension board according to claim 5.   The metal support substrate has an opening, and the connection portion electrically connects the conductive layer exposed from the opening of the metal support substrate and the insulating layer, and the metal support substrate. The suspension board according to claim 5, wherein:   5. The device according to claim 1, wherein the connection region is a gimbal region, and the connection part electrically connects the conductive layer and the element that is the connected member. The suspension board according to any one of the claims.   The suspension board according to claim 8, wherein the element is a magnetic head slider or an actuator.   2. The connection area is a relay board connection area, and the connection part electrically connects the conductive layer and a terminal part of the relay board as the connected member. The suspension board according to claim 4. A conductive layer; a gold plating layer formed on the surface of the conductive layer to prevent corrosion of the conductive layer; and a connection portion for electrically connecting the conductive layer and the connected member via the gold plating layer. A method for manufacturing a suspension board having a connection region having
A method of manufacturing a suspension board, comprising: a connecting portion forming step of forming the connecting portion by dropping an Au-Sn alloy containing Au as a main component in a molten state. A conductive layer; a gold plating layer formed on the surface of the conductive layer to prevent corrosion of the conductive layer; and a connection portion for electrically connecting the conductive layer and the connected member via the gold plating layer. A method for manufacturing a suspension board having a connection region having
A method for manufacturing a suspension board, comprising: a connecting portion forming step of forming the connecting portion by dropping an alloy containing Au as a main component and having a melting point of 450 ° C. or lower in a molten state. A conductive layer; a gold plating layer formed on the surface of the conductive layer to prevent corrosion of the conductive layer; and a connection portion for electrically connecting the conductive layer and the connected member via the gold plating layer. A suspension board having a connection region having
A suspension board, wherein the gold plating layer has a thickness of 0.5 μm or less.

Images