JP6100725B2 - Suspension substrate manufacturing method - Google Patents

Description

  The present invention relates to a suspension substrate having excellent connection terminal strength.

  2. Description of the Related Art A suspension board on which elements such as a magnetic head slider are mounted is known as a circuit board used for an HDD (Hard Disk Drive). The suspension substrate usually has a basic structure in which a metal support substrate (for example, SUS), an insulating layer (for example, polyimide resin), and a wiring layer (for example, Cu) are laminated in this order. And an external circuit board connection area for connecting to an external circuit board at the other end.

  In order to make an electrical connection between the element and an external circuit board, the suspension board is usually provided with a connection terminal region including a connection terminal. This connection terminal usually has a flying structure protruding from the metal support substrate. There are various reasons for this. One of the reasons is that if the connecting terminal does not have a flying structure, the insulating layer located under the connecting terminal is melted by heat during soldering, and the connecting terminal And the metal support substrate may be short-circuited. On the other hand, since the connection terminal of the flying structure is not supported by the metal support substrate, there is a problem that the mechanical strength is low and the connection terminal is easily deformed.

  Here, in Patent Document 1, a pattern termination portion serving as a connection terminal for connection to a terminal of a magnetic head is formed in a circuit pattern, and an end surface of the pattern termination portion is an end surface of an insulating layer immediately below the pattern termination portion. There is disclosed a suspension board with circuit that is aligned or protrudes in the distal direction from the end face of the insulating layer. In this technique, the insulating layer has a specific shape so that the insulating layer is not easily irradiated with laser light even when laser light is irradiated around the solder balls. However, as described later, in the method described in Patent Document 1, the insulating layer cannot be processed with high accuracy, and it is difficult to align the end face of the pattern termination portion and the end face of the insulating layer. it is conceivable that. As a result, there is a problem that the pattern end portion is not supported by the insulating layer and is likely to be deformed.

  Further, in Patent Document 2, in the polyimide film etching method, first, a photosensitive resin layer is arranged on both sides of the polyimide film, and exposure development is performed to form a resist pattern, and then the obtained resist It is described that the pattern is further irradiated with ultraviolet rays to improve the hardness of the resist pattern. This technique relates to processing of a polyimide resin useful as a material for an insulating layer, and is intended to improve the resist pattern etching resistance by further ultraviolet irradiation. However, even if the etching resistance of the resist pattern is improved, the adhesion between the polyimide resin and the resist pattern is not sufficient, as described later, so that the etching solution penetrates between the two, and the insulating layer is processed. There is a problem that it cannot be performed with high accuracy.

JP 2006-120288 A JP 2001-305750 A

  The present invention has been made in view of the above problems, and has as its main object to provide a suspension substrate having excellent connection terminal strength.

  In order to solve the above problems, in the present invention, a metal support substrate, an insulating layer formed on the metal support substrate, and a wiring layer formed on the insulating layer are provided. The wiring layer protrudes from the end of the metal support substrate and has a wiring layer protrusion that constitutes a connection terminal. In the connection terminal region, the insulating layer is more than the end of the metal support substrate. A suspension substrate, characterized in that it has an insulating layer protruding portion that protrudes and supports the wiring layer protruding portion, and an end portion of the wiring layer protruding portion and an end portion of the insulating layer protruding portion are coincident with each other. provide.

  According to the present invention, since the end of the wiring layer protrusion matches the end of the insulating layer protrusion, the wiring layer protrusion can be effectively reinforced by the insulating layer protrusion, and external force, etc. It is possible to suppress the deformation of the wiring layer protrusion due to. As a result, a suspension substrate with excellent connection terminal strength can be obtained.

  In the above invention, the connection terminal region is preferably a region for connecting to an element.

  In the above invention, it is preferable that the exposed width of the wiring layer protrusion exposed from the insulating layer protrusion is 3 μm or less.

  In the said invention, it is preferable that the edge part of the said insulating-layer protrusion part is a taper shape in which the lower end part protruded rather than the upper end part. This is because the thickness of the insulating layer protrusion at the upper end of the insulating layer protrusion can be increased, and the deformation of the wiring layer protrusion can be effectively prevented.

  In the above invention, the insulating layer has the insulating layer protruding portion and an insulating layer supporting portion that supports the root of the insulating layer protruding portion, and the intersection of the insulating layer protruding portion and the insulating layer supporting portion is A curved shape is preferred. This is because the strength of the connection terminal can be further improved by making the base of the protruding portion of the insulating layer that easily deforms into a curved shape.

  In the above invention, the insulating layer includes the insulating layer protruding portion and an insulating layer supporting portion that supports a base of the insulating layer protruding portion, and an end portion of the insulating layer supporting portion is formed on the metal supporting substrate. It is preferable to protrude from the end.

  In the present invention, a laminate having a metal support member, an insulating member formed on the metal supporting member, and a wiring layer formed on the insulating member at a position where the connection terminal region is formed. The layered body preparation step to be prepared and the insulating layer protrusion that supports the wiring layer protruding portion by wet-etching the insulating member by using, as a resist, the wiring layer protruding portion constituting the connection terminal in the wiring layer. After the insulating member etching step for forming an insulating layer having a portion and the insulating member etching step, the metal supporting member is etched to form a metal supporting substrate, and the wiring layer protruding portion and the insulating layer protruding portion are There is provided a method for manufacturing a suspension substrate, comprising: a metal support member etching step that protrudes from an end portion of the metal support substrate.

  According to the present invention, the end of the wiring layer protruding portion and the insulating layer are etched by using the portion of the wiring layer that becomes the wiring layer protruding portion as a resist and etching the insulating member before etching the metal supporting member. A suspension substrate in which the end portions of the layer protrusions coincide can be obtained.

  In the above invention, in the insulating member etching step, the resist pattern is formed so that a curved shape is formed at the intersection of the insulating layer protruding portion and the insulating layer supporting portion supporting the base of the insulating layer protruding portion. It is preferable to form and wet-etch the insulating member. This is because the strength of the connection terminal can be further improved by making the base of the protruding portion of the insulating layer that easily deforms into a curved shape.

  In the above invention, in the metal support member etching step, the metal support member is etched so that the insulating layer support portion that supports the base of the insulating layer protrusion portion protrudes from the end portion of the metal support substrate. It is preferable.

  The present invention also provides a suspension including the above-described suspension substrate.

  According to the present invention, a suspension having excellent connection stability can be obtained by using the suspension substrate described above.

  The present invention also provides an element-equipped suspension comprising the above-described suspension and an element mounted in an element mounting region of the suspension.

  According to the present invention, by using the above-described suspension, a suspension with an element having excellent connection stability can be obtained.

  The present invention also provides a hard disk drive including the above-described suspension with an element.

  According to the present invention, a hard disk drive with higher functionality can be obtained by using the above-described suspension with an element.

  In the present invention, there is an effect that a suspension substrate having excellent connection terminal strength can be obtained.

It is a schematic plan view which shows an example of the board | substrate for suspensions of this invention. It is a schematic diagram explaining the board | substrate for suspensions of this invention. It is a schematic sectional drawing explaining the board | substrate for suspensions of this invention. It is a schematic sectional drawing explaining the board | substrate for suspensions of this invention. It is a schematic diagram explaining the board | substrate for suspensions of this invention. It is a schematic plan view explaining the board | substrate for suspensions of this invention. It is a schematic sectional drawing explaining an example of the manufacturing method of the board | substrate for suspensions of this invention. It is a schematic sectional drawing explaining the difference between the manufacturing method of the conventional suspension board | substrate, and the manufacturing method of the suspension board | substrate of this invention. It is a schematic diagram explaining the manufacturing method of the board | substrate for suspensions of this invention. It is a schematic plan view which shows an example of the suspension of this invention. It is a schematic plan view which shows an example of the suspension with an element of this invention. It is a schematic plan view which shows an example of the hard disk drive of this invention. It is a schematic sectional drawing which shows the manufacturing method of the board | substrate for suspensions of a comparative example.

  The suspension substrate, suspension substrate manufacturing method, suspension, suspension with element, and hard disk drive of the present invention will be described in detail below.

A. First, the suspension substrate of the present invention will be described. The suspension substrate of the present invention includes a metal support substrate, an insulating layer formed on the metal support substrate, and a wiring layer formed on the insulating layer. In the connection terminal region, the wiring layer is A wiring layer protruding portion that protrudes from an end portion of the metal support substrate and constitutes a connection terminal. In the connection terminal region, the insulating layer protrudes from an end portion of the metal support substrate, and the wiring layer An insulating layer protruding portion that supports the protruding portion is provided, and an end portion of the wiring layer protruding portion and an end portion of the insulating layer protruding portion coincide with each other.

  FIG. 1 is a schematic plan view showing an example of the suspension substrate of the present invention. For convenience, the description of the insulating layer and the cover layer is omitted. A suspension substrate 20 shown in FIG. 1 is formed on the head portion side, an element mounting region 11 for mounting elements, and an external circuit substrate connection region 12 formed on the tail portion side for connection to an external circuit substrate. And wiring layers 13 (13a to 13d) for electrically connecting the element mounting region 11 and the external circuit board connection region 12. The wiring layers 13a and 13b and the wiring layers 13c and 13d form a wiring pair, one for recording and the other for reproduction.

  FIG. 2A is an enlarged view in which the periphery of the head portion in FIG. 1 is enlarged. For convenience, the cover layer is not shown. As illustrated in FIG. 2A, the wiring layers 13 a to 13 d are formed so as to be connected to elements mounted in the element mounting region 11. Moreover, FIG.2 (b) is AA sectional drawing of Fig.2 (a). The suspension substrate shown in FIG. 2B has a metal support substrate 1, an insulating layer 2 formed on the metal support substrate 1, and a wiring layer 3 formed on the insulating layer 2. . Further, in the connection terminal region X, the wiring layer 3 has a wiring layer protruding portion 3A that protrudes from the end portion 1a of the metal support substrate 1 and constitutes a connection terminal. Further, in the connection terminal region X, the insulating layer 2 has an insulating layer protrusion 2A that protrudes from the end 1a of the metal support substrate 1 and supports the wiring layer protrusion 3A. Furthermore, the positions of the end 3a of the wiring layer protrusion 3A and the end 2a of the insulating layer protrusion 2A are the same. Note that “match” in the present invention is not only a complete match but also a concept having a certain extent.

  FIG. 2C is an enlarged view showing the periphery of the connection terminal region X. In the present invention, the exposed width W of the wiring layer protruding portion 3A exposed from the insulating layer protruding portion 2A is preferably 3 μm or less. In the present invention, the end 2 a of the insulating layer protrusion 2 </ b> A preferably has a tapered shape in which the lower end 22 protrudes from the upper end 21.

  As shown in FIG. 3, the wiring layer protrusion 3 </ b> A in the connection terminal area X and the connection terminal 23 of the element 24 mounted in the element mounting area 11 are electrically connected by solder balls 25.

  According to the present invention, since the end of the wiring layer protrusion matches the end of the insulating layer protrusion, the wiring layer protrusion can be effectively reinforced by the insulating layer protrusion, and external force, etc. It is possible to suppress the deformation of the wiring layer protrusion due to. As a result, a suspension substrate with excellent connection terminal strength can be obtained.

  Further, in FIG. 3A of Patent Document 1 described above, a suspension substrate in which the end of the wiring layer protruding portion and the end of the insulating layer protruding portion coincide is described. There is no description about the manufacturing method. Furthermore, there is a problem of penetration of the etching solution described later, and it is difficult to match the end of the wiring layer protrusion with the end of the insulating layer protrusion by the conventional method. Therefore, it is considered that Patent Document 1 does not substantially disclose a suspension substrate in which the end of the wiring layer protrusion and the end of the insulating layer protrusion match. The problem of the penetration of the etching solution will be described in detail with reference to FIG.

In addition, the suspension substrate of the present invention has a great feature in that the insulating layer protruding portion exists up to the position of the end portion of the wiring layer protruding portion. Since the insulating layer protrusions exist up to the end of the wiring layer protrusions, good shape retention can be achieved up to the ends of the wiring layer protrusions in the thickness direction. There is also an advantage that the positional accuracy in the height direction in the connection can be improved.
Hereinafter, the suspension substrate of the present invention will be described separately for the suspension substrate member and the suspension substrate configuration.

1. First, members of the suspension substrate of the present invention will be described. The suspension substrate of the present invention has at least a metal support substrate, an insulating layer, and a wiring layer.

  The metal support substrate in the present invention is usually used as a support substrate for a suspension substrate. The material of the metal support substrate is not particularly limited, but is preferably a metal having a spring property. Examples of the material for the metal support substrate include SUS. Moreover, although the thickness of a metal support substrate changes with kinds of the material, it exists in the range of 10 micrometers-20 micrometers, for example.

  The insulating layer in the present invention is a layer formed on a metal support substrate. Examples of the material for the insulating layer include polyimide resin (PI). In addition, the material of the insulating layer may be a photosensitive material or a non-photosensitive material. Moreover, the thickness of an insulating layer exists in the range of 5 micrometers-10 micrometers, for example.

  The wiring layer in the present invention is formed on the insulating layer. Examples of the material for the wiring layer include metals, and copper (Cu) is preferable among them. The thickness of the wiring layer is, for example, in the range of 5 μm to 18 μm, and preferably in the range of 9 μm to 12 μm. The wiring layer in this invention may be coat | covered with the plating part. An example of the plating part is a gold plating part. Moreover, the nickel plating part may be formed as a foundation | substrate of a gold plating part. The thickness of the plating portion is, for example, in the range of 0.1 μm to 4.0 μm.

  The suspension substrate of the present invention preferably has a cover layer that covers the wiring layer. Examples of the material for the cover layer include polyimide resin (PI). The material of the cover layer may be a photosensitive material or a non-photosensitive material. Although the thickness of a cover layer is not specifically limited, For example, it is preferable to exist in the range of 2 micrometers-30 micrometers, and it is more preferable to exist in the range of 2 micrometers-10 micrometers.

2. Next, the configuration of the suspension substrate of the present invention will be described. The suspension substrate of the present invention has a connection terminal region. The connection terminal area may be an area for connecting to an element as shown in FIG. 2 or an area for connecting to an external circuit board such as a relay board. In the former case, the connection terminal region is formed on the head portion side of the suspension substrate, for example, and in the latter case, the connection terminal region is formed on the tail portion side of the suspension substrate, for example. Examples of the element mounted on the suspension substrate include a magnetic head slider, an actuator, and a semiconductor. The actuator may have a magnetic head or may not have a magnetic head.

  In the present invention, as shown in FIG. 2C, when the exposed width of the wiring layer protrusion 3A exposed from the insulating layer protrusion 2A is W, W is preferably 3 μm or less, and preferably 2 μm or less. More preferably, it is more preferably 1 μm or less, and particularly preferably 0.5 μm or less. This is because the deformation of the wiring layer protrusion 3A can be prevented more effectively.

  In the present invention, as shown in FIG. 2C, the end 2 a of the insulating layer protrusion 2 </ b> A preferably has a tapered shape in which the lower end 22 protrudes from the upper end 21. This is because the thickness of the insulating layer protrusion 2A at the upper end 21 of the insulating layer protrusion 2A can be increased, and the deformation of the wiring layer protrusion 3A can be effectively prevented. When this taper angle is α, the taper angle α is preferably 45 ° or more, and more preferably in the range of 45 ° to 85 °. In the present invention, as shown in FIG. 4, the lower end 22 of the insulating layer protrusion 2A may protrude beyond the end 3a of the wiring layer protrusion 3A. In this case, the thickness of the insulating layer protrusion 2A at the end 3a of the wiring layer protrusion 3A can be sufficiently increased, and deformation of the wiring layer protrusion 3A can be prevented more effectively.

In the connection terminal region, the wiring layer and the insulating layer have a wiring layer protruding portion and an insulating layer protruding portion that protrude from the end portion of the metal support substrate, respectively. Here, FIG. 5A is a schematic sectional view showing the periphery of the connection terminal region in the present invention, FIG. 5B is a schematic plan view of FIG. 5A observed from the wiring layer 3 side, FIG. 5C is a schematic plan view of FIG. 5A observed from the metal support substrate 1 side. In the present invention, as shown in FIG. 5A, the length L ₃ from which the wiring layer protruding portion 3A protrudes from the end portion 1a of the metal support substrate 1 is preferably in the range of 25 μm to 80 μm, for example. . Further, as shown in FIG. 5 (b), the width _{W 3} of the wiring layer protruding section 3A, for example, preferably in the range of 25Myuemu～80myuemu.

  Further, as can be seen by comparing FIG. 5B and FIG. 5C, in the present invention, the shape of the insulating layer protrusion 2A is substantially the same as the shape of the corresponding wiring layer protrusion 3A in plan view. become. Furthermore, not only the length direction X of the insulating layer protrusion 2A but also the width direction Y of the insulating layer protrusion 2A is substantially the same as the shape of the wiring layer protrusion 3A. The reason why such a shape is obtained is that, as will be described later, by using the insulating layer protrusion 2A as a resist, the penetration of the etching solution can be prevented, and the processing of the insulating layer can be performed with high accuracy. .

Further, in the present invention, as shown in FIG. 5C, the insulating layer 2 has an insulating layer protruding portion 2A and an insulating layer supporting portion 2B that supports the base of the insulating layer protruding portion 2A. It is preferable that the end portion 2 b of the layer support portion 2 </ b> B protrudes from the end portion 1 a of the metal support substrate 1. This is because such a structure can prevent the wiring layer protrusion 3A and the metal supporting board 1 from coming into contact with each other and short-circuiting during, for example, bending. In addition, the deformation of the wiring layer protrusion 3A can be prevented. Further, when the end portion 2b of the insulating layer support portion 2B does not protrude from the end portion 1a of the metal support substrate 1, the wiring layer protrusion portion 3A and the metal support substrate 1 may come into contact with each other and be short-circuited during bending, There is also a possibility of short-circuiting when soldering after bending. Therefore, from the viewpoint of facilitating bending, it is preferable to remove the metal support substrate 1 at the tip (protrusion) to form a flying structure. Here, if the length of the insulating layer protrusion 2A protrudes from the end portion 1a of the metal supporting board 1 was L _2, L ₂ is the length L ₂₁ of the insulating layer protrusion 2A, the insulating layer supporting section 2B it can be expressed as the sum of the length L ₂₂ of. L ₂₂ / L ₂ is, for example, preferably 50% or more, and more preferably in the range of 50% to 80%. L ₂₂ is preferably 40 μm or more, for example, and more preferably in the range of 40 μm to 80 μm. On the other hand, L ₂₁ is preferably in the range of 20 μm to 60 μm, for example, and more preferably in the range of 20 μm to 40 μm. In addition, in FIG.5 (c), although the insulating layer 2 illustrated what has the insulating layer support part 2B, the insulating layer 2 in this invention may not have the insulating layer support part 2B.

  6A is a schematic plan view of the connection terminal region observed from the metal support substrate 1 side, as in FIG. 5C. FIG. 6B shows the connection terminal region of the wiring layer 3. It is the schematic plan view observed from the side. In the present invention, as shown in FIGS. 6A and 6B, the insulating layer 2 has an insulating layer protrusion 2A and an insulating layer support 2B that supports the base of the insulating layer protrusion 2A. The intersection of the insulating layer protrusion 2A and the insulating layer support 2B is preferably a curved shape C. This is because the strength of the connection terminal can be further improved by making the base of the insulating layer protruding portion 2A that easily deforms into a curved shape. Furthermore, the curved shape C is preferably an arc shape, and the radius thereof is preferably in the range of 3 μm to 30 μm, for example.

B. Next, a method for manufacturing a suspension substrate according to the present invention will be described. According to the suspension board manufacturing method of the present invention, a metal support member, an insulating member formed on the metal support member, and a wiring layer formed on the insulating member are formed at positions where the connection terminal regions are formed. A laminate preparation step for preparing a laminate having the wiring layer, and a portion of the wiring layer that becomes a wiring layer protrusion constituting the connection terminal as a resist, and wet etching the insulating member to support the wiring layer protrusion An insulating member etching step for forming an insulating layer having an insulating layer protrusion, and after the insulating member etching step, the metal support member is etched to form a metal support substrate, and the wiring layer protrusion and the insulating layer And a metal supporting member etching step for causing the protruding portion to protrude from the end portion of the metal supporting substrate.

  FIG. 7 is a schematic cross-sectional view illustrating an example of a method for manufacturing a suspension substrate according to the present invention. In the suspension board manufacturing method in FIG. 7, first, the metal support member 1X, the insulating member 2X formed on the metal support member 1X, and the insulating member 2X are formed at positions where the connection terminal regions are formed. A laminated member having the wiring member 3X prepared is prepared (FIG. 7A). Next, a resist pattern is produced on the wiring member 3X using DFR (dry film resist), and the wiring member 3X exposed from the resist pattern is wet-etched to form the wiring layer 3 (FIG. 7). (B)). At this time, etching of the metal support member 1X in a portion not shown may be performed at the same time. Next, the cover layer 4 is formed on the wiring layer 3 so that at least a part of the portion that becomes the wiring layer protrusion 3A is exposed. Thereby, the laminated body in this invention is obtained (FIG.7 (c)).

  Thereafter, a resist pattern 9 is formed on the wiring layer 3 so as to expose at least a part of the portion that becomes the wiring layer protrusion 3A (FIG. 7D). The resist pattern 9 is mainly for protecting the insulating member 2X exposed from between the plurality of wiring layers 3. Next, the insulating member 2X is wet-etched using a portion of the wiring layer 3 that becomes the wiring layer protrusion 3A as a resist, and the insulating layer 2 having the insulating layer protrusion 2A that supports the wiring layer protrusion 3A is formed. (FIG. 7 (e)). Next, the resist pattern 9 is peeled off (FIG. 7F), and the plated portion 5 is formed on the exposed wiring layer 3 (FIG. 7G). Finally, the metal support member 1X at the position where the connection terminal region is formed is removed by wet etching to form the metal support substrate 1 to obtain the suspension substrate 20 (FIG. 7 (h)).

  According to the present invention, the end of the wiring layer protruding portion and the insulating layer are etched by using the portion of the wiring layer that becomes the wiring layer protruding portion as a resist and etching the insulating member before etching the metal supporting member. A suspension substrate in which the end portions of the layer protrusions coincide can be obtained. In this suspension substrate, since the end of the wiring layer protrusion and the end of the insulating layer protrusion coincide with each other, the wiring layer protrusion can be effectively reinforced with the insulating layer protrusion. It is possible to suppress the deformation of the wiring layer protrusion due to. As a result, a suspension substrate with excellent connection terminal strength can be obtained.

  Next, the difference between the conventional method for manufacturing a suspension substrate and the method for manufacturing a suspension substrate of the present invention will be described with reference to FIG. As shown in FIG. 8A, in the conventional manufacturing method, after the metal support member is etched to form the metal support substrate 1, the insulating member 2X is etched. Therefore, usually, the resist pattern 9 is formed on both surfaces of the object to be etched. At this time, as a material of the resist pattern 9, a solvent type photoresist or an alkali development peeling type photoresist is typically used. Here, since the adhesion between the insulating member 2X and the resist pattern 9 is not high, the etching solution (typically an alkaline etching solution) of the insulating member 2X penetrates from the portion indicated by Y in the drawing. As a result, as shown in FIG. 8B, the insulating layer 2 that is excessively etched is formed.

On the other hand, as shown in FIG. 8C, in the present invention, the insulating member 2X is etched before the metal supporting member 1X is etched. Since the adhesiveness between the insulating member 2X and the metal support member 1X is high, it is possible to prevent the etching solution (typically an alkaline etching solution) of the insulating member 2X from being infiltrated. As a result, a suspension substrate in which the end 3a of the wiring layer protrusion 3A and the end 2a of the insulating layer protrusion 2A coincide with each other can be obtained. Further, since the metal support member 1X is in a state before etching, the tapered insulating layer 2 tends to be easily generated by the liquid flow. It is considered that this tapered shape cannot be formed by a conventional manufacturing method.
Hereinafter, the method for manufacturing a suspension substrate according to the present invention will be described step by step.

1. Laminate Preparation Step In the laminate preparation step of the present invention, a metal support member, an insulating member formed on the metal support member, and a wiring layer formed on the insulating member are formed at positions where connection terminal regions are formed. (A) to (c)).

  The method for forming the laminate is not particularly limited as long as the desired laminate can be obtained. As an example of the method for forming the laminated body, as shown in FIGS. 7A to 7C, a method using a laminated member can be exemplified.

  When using a laminated member having a metal support member, an insulating member, and a wiring member, the wiring layer is formed by etching the wiring member. Although the method for etching the wiring member is not particularly limited, specific examples include wet etching. The type of etchant used for wet etching is preferably selected as appropriate according to the type of wiring member. For example, when the material of the wiring member is copper, an iron chloride-based etching solution or the like can be used. In the present invention, a resist pattern is usually formed using DFR or the like, and the wiring member exposed from the resist pattern is etched.

  Moreover, the laminated body in this invention may further have a cover layer which covers a wiring layer. The method for forming the cover layer is preferably selected as appropriate depending on the material type of the cover layer. For example, when the material of the cover layer is a photosensitive material, the cover layer having a predetermined pattern can be formed by exposure and development. On the other hand, when the material of the cover layer is a non-photosensitive material, the cover layer having a predetermined pattern can be formed by etching through the resist pattern.

  In addition, about each member used for a laminated body, it is the same as that of the content described in the said "A. suspension board | substrate". In the present invention, a laminate may be formed by an additive method.

2. Insulating Member Etching Step Next, the insulating member etching step in the present invention will be described. In the insulating member etching step according to the present invention, in the wiring layer, the insulating layer is formed by wet-etching the insulating member using a portion serving as a wiring layer protruding portion constituting the connection terminal as a resist, and supporting the wiring layer protruding portion. This is a step of forming an insulating layer having a protrusion (FIGS. 7D to 7F).

  The type of the etching solution used for wet etching of the insulating member is preferably selected as appropriate according to the type of the insulating layer. For example, when the material of the insulating member is a polyimide resin, an alkaline etching solution or the like can be used. .

  One feature of the present invention is that the portion of the wiring layer that becomes the wiring layer protrusion is used as a resist. As described above, since the adhesion between the wiring layer and the insulating member is higher than the adhesion between the resist pattern using DFR or the like and the insulating layer, the penetration of the etching solution can be prevented, which is substantially the same as the wiring layer protruding portion. Insulating layer protrusions having the same shape can be formed. Further, since the wiring layer is not usually etched by the etching solution for the insulating member, it is useful as a resist for the insulating member.

  In the present invention, in the insulating member etching process, a resist pattern is formed so that a curved shape is formed at the intersection of the insulating layer protrusion and the insulating layer support that supports the base of the insulating layer protrusion. In addition, it is preferable to wet-etch the insulating member. This is because the strength of the connection terminal can be further improved by making the base of the insulating layer protruding portion that is likely to be deformed into a curved shape. Specifically, as shown in FIGS. 9A and 9B, it is preferable to provide a curved shape C in the resist pattern 9 formed on the wiring layer 3. The curved shape C can be obtained by performing predetermined exposure and development when forming the resist pattern 9.

3. Metal Support Member Etching Step Next, the metal support member etching step in the present invention will be described. In the metal support member etching step of the present invention, after the insulating member etching step, the metal support member is etched to form a metal support substrate, and the wiring layer protruding portion and the insulating layer protruding portion are formed on the metal supporting substrate. This is a step of projecting from the end (FIG. 7 (h)).

  Although the method for etching the metal support member is not particularly limited, specific examples include wet etching. The type of etchant used for wet etching is preferably selected as appropriate according to the type of metal support member. For example, when the material of the metal support member is SUS, an iron chloride-based etchant or the like can be used. In the present invention, a resist pattern is usually formed using DFR or the like, and the metal support member exposed from the resist pattern is etched.

  In the present invention, in the metal support member etching step, it is preferable that the metal support member is etched so that the insulating layer support portion that supports the base of the insulating layer protrusion portion protrudes from the end portion of the metal support substrate. This is because such a structure can prevent the wiring layer protruding portion and the metal supporting board from coming into contact with each other and short-circuiting during bending, for example.

4). Other Steps In the present invention, in addition to the steps described above, it is preferable to have a plating portion forming step for forming a plating portion on the surface of the wiring layer exposed in the connection terminal region (FIG. 7G). Examples of the method for forming the plating portion include an electrolytic plating method. Further, the suspension substrate obtained by the present invention is the same as the content described in the above-mentioned “A. Suspension substrate”, and therefore description thereof is omitted here.

C. Suspension Next, the suspension of the present invention will be described. The suspension of the present invention includes the above-described suspension substrate.

  According to the present invention, a suspension having excellent connection stability can be obtained by using the suspension substrate described above.

  FIG. 10 is a schematic plan view showing an example of the suspension of the present invention. A suspension 50 shown in FIG. 10 includes the above-described suspension substrate 20 and a load beam 40 provided on the surface of the suspension substrate 20 opposite to the surface on which the element mounting region 11 is formed. is there.

  The suspension of the present invention has at least a suspension substrate, and usually further has a load beam. The suspension substrate is the same as the content described in “A. Suspension substrate”, and therefore, the description thereof is omitted here. The load beam can be the same as the load beam used for a general suspension.

D. Next, the suspension with an element of the present invention will be described. A suspension with an element of the present invention includes the above-described suspension and an element mounted in an element mounting region of the suspension.

  According to the present invention, by using the above-described suspension, a suspension with an element having excellent connection stability can be obtained.

  FIG. 11 is a schematic plan view showing an example of the suspension with an element of the present invention. A suspension 60 with an element shown in FIG. 11 includes the suspension 50 described above and an element 51 mounted on the element mounting region 11 of the suspension 50.

  The suspension with an element of the present invention has at least a suspension and an element. The suspension is the same as the content described in “C. Suspension”, and therefore, the description thereof is omitted here.

E. Next, the hard disk drive of the present invention will be described. The hard disk drive of the present invention is characterized by including the above-described suspension with an element.

  According to the present invention, a hard disk drive with higher functionality can be obtained by using the above-described suspension with an element.

  FIG. 12 is a schematic plan view showing an example of the hard disk drive of the present invention. The hard disk drive 70 shown in FIG. 12 includes the above-described suspension 60 with an element, a disk 61 on which the element suspension 60 writes and reads data, a spindle motor 62 that rotates the disk 61, and the elements of the suspension 60 with an element. Arm 63 and voice coil motor 64, and a case 65 for sealing the above members.

  The hard disk drive of the present invention has at least a suspension with an element, and usually further includes a disk, a spindle motor, an arm, and a voice coil motor. The suspension with an element is the same as that described in the above “D. Suspension with an element”, and therefore description thereof is omitted here. As other members, the same members as those used in a general hard disk drive can be used.

  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]
A suspension substrate was produced in the same manner as shown in FIG. First, a laminated member having a metal supporting member 1X that is 20 μm thick stainless steel (SST), an insulating member 2X that is 10 μm thick polyimide resin, and a wiring member 3X that is 9 μm thick plated copper is prepared. (FIG. 7A). Next, the surface of the wiring member 3X of the laminated member is covered with an acrylic photosensitive dry film, and exposure / development is performed to form a predetermined resist pattern. Thereafter, the wiring member 3X exposed from the resist pattern is chlorinated. Wiring layer 3 was formed by wet etching using an iron-based etchant (FIG. 7B). Next, the cover layer 4 was formed using the non-photosensitive polyimide resin described in JP2008-310946A (FIG. 7C).

Thereafter, an acrylic photosensitive dry film (thickness 38 μm) is placed on the surface of the wiring layer 3 of the obtained laminate, and ultraviolet rays with an irradiation amount of 150 mJ / cm ² are irradiated from a high pressure mercury lamp using a photomask. Further, a predetermined resist pattern 9 was formed by spray development using an aqueous Na ₂ CO ₃ solution having a concentration of 1 wt% (FIG. 7D). Next, the insulating member 2X was etched with an organic alkali etching solution under the condition of 80 ° C. for 3 minutes while allowing the etching solution to overflow from the upper side surface of the etching tank (FIG. 7E). Next, a 1 wt% sodium hydroxide aqueous solution heated to 50 ° C. was sprayed at a spray pressure of 1 kg / cm ² to peel off the resist pattern 9 (FIG. 7F). Then, the plating part 5 was formed, and the metal support member 1X was etched (FIGS. 7G and 7H). Thus, a suspension substrate was obtained.

  The obtained suspension substrate had a tapered shape in which the end portion of the insulating layer protruding portion protruded from the upper end portion at the lower end portion, and the taper angle was 79 °. Further, the exposed width of the wiring layer protrusion exposed from the insulating layer protrusion was 1 μm. Further, the film thickness change of the protruding portion of the insulating layer did not occur, and the original film thickness could be maintained. Further, when the ratio of occurrence of wrinkles (deformation) in the wiring layer protruding portion was measured with a stereomicroscope, the deformation occurrence rate was 0%.

[Comparative example]
A suspension substrate was produced by the method shown in FIG. First, a laminated member having a metal supporting member 1X that is 20 μm thick stainless steel (SST), an insulating member 2X that is 10 μm thick polyimide resin, and a wiring member 3X that is 9 μm thick plated copper is prepared. (FIG. 13A). Next, both surfaces of the laminated member are covered with an acrylic photosensitive dry film, and a predetermined resist pattern is formed by performing exposure and development, and then the wiring member 3X and the metal support member 1X exposed from the resist pattern are The wiring layer 3 and the metal support substrate 1 were formed by wet etching using an iron chloride-based etchant (FIG. 13B). Next, the cover layer 4 was formed using the non-photosensitive polyimide resin described in JP2008-310946A (FIG. 13C).

Thereafter, an acrylic photosensitive dry film (thickness: 38 μm) is arranged on both sides of the obtained laminate, irradiated with ultraviolet rays with a dose of 150 mJ / cm ² from a high-pressure mercury lamp using a photomask, A predetermined resist pattern 9 was formed by spray development using a 1 wt% Na ₂ CO ₃ aqueous solution (FIG. 13D). At this time, the opening of the metal support substrate 1 was protected by the resist pattern 9. Next, the insulating member 2X was etched with an organic alkali etching solution under conditions of 80 ° C. for 3 minutes while allowing the etching solution to overflow from the upper side surface of the etching tank (FIG. 13E). Next, a 1 wt% sodium hydroxide aqueous solution heated to 50 ° C. was sprayed at a spray pressure of 1 kg / cm ² to peel off the resist pattern 9 (FIG. 13F). Then, the plating part 5 was formed and the board | substrate for suspensions was obtained (FIG.13 (g)).

  The obtained suspension substrate had an inverted taper shape in which the end portion of the insulating layer protruding portion protruded from the lower end portion, and the taper angle was 40 °. Further, the exposed width of the wiring layer protrusion exposed from the insulating layer protrusion was 5 μm. Furthermore, the film thickness of the insulating layer protruding portion was reduced by etching, and the film thickness became half or less of the initial value in the range from the end of the insulating layer protruding portion to about 10 μm. Further, when the ratio of occurrence of wrinkles (deformation) in the wiring layer protruding portion was measured with a stereomicroscope, the deformation occurrence rate was 3.5%.

  DESCRIPTION OF SYMBOLS 1 ... Metal support board, 1X ... Metal support member, 2 ... Insulating layer, 2A ... Insulating layer protrusion part, 2X ... Insulating member, 3 ... Wiring layer, 3A ... Wiring layer protrusion part, 3X ... Wiring member, 4 ... Cover layer DESCRIPTION OF SYMBOLS 5 ... Plating part, 11 ... Element mounting area | region, 12 ... External circuit board connection area | region, 13 ... Wiring layer, 20 ... Suspension board | substrate, 21 ... Upper end part of insulating layer protrusion part, 22 ... Lower end part of insulating layer protrusion part , 23 ... element connection terminals, 24 ... element, 25 ... solder balls, 30 ... laminate, X ... connection terminal area

Claims (3)

A laminate preparation step of preparing a laminate having a metal support member, an insulating member formed on the metal support member, and a wiring layer formed on the insulating member at a position where the connection terminal region is formed; ,
In the wiring layer, the insulating layer and the wiring layer protruding portion are supported by the metal support member using the portion that becomes the wiring layer protruding portion constituting the connection terminal as a resist. The member is wet-etched to form an insulating layer having an insulating layer protruding portion that supports the wiring layer protruding portion and has a tapered shape in which the end portion on the metal supporting member side protrudes from the end portion on the wiring layer side. Insulating member etching step;
After the insulating member etching step, the metal support member is etched to form a metal support substrate, and the wiring layer protrusion and the insulating layer protrusion are protruded from the end of the metal support substrate. Process,
A method for manufacturing a suspension substrate, comprising: In the insulating member etching step, a resist pattern is formed so that a curved shape is formed at an intersection of the insulating layer protruding portion and an insulating layer supporting portion that supports a base of the insulating layer protruding portion, and the insulating The method for manufacturing a suspension substrate according to claim 1, wherein the member is wet-etched. In the metal support member etching step, the metal support member is etched so that an insulating layer support portion supporting a base of the insulating layer protrusion portion protrudes from an end portion of the metal support substrate. The manufacturing method of the board | substrate for suspensions of Claim 1 or Claim 2.

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