JP6174838B2 - Suspension substrate, suspension, suspension with element, hard disk drive, and manufacturing method of suspension substrate - Google Patents

Description

  The present invention relates to a suspension board in which corrosion of a terminal portion is prevented.

  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. The suspension substrate (flexure) used in the HDD is, for example, a metal support substrate (for example, stainless steel), an insulating layer (for example, polyimide resin), a wiring layer (for example, copper), and a cover layer (for example, polyimide resin) laminated in this order. It has a basic structure.

  In addition, a wiring covering layer (for example, Ni plating) may be provided between the wiring layer and the cover layer. By providing the wiring covering layer, the metal constituting the wiring layer can be prevented from diffusing into the cover layer. Furthermore, the adhesion between the wiring layer and the cover layer can be improved. In addition, the wiring layer of the suspension substrate usually has a terminal portion that is electrically connected to the recording / reproducing element or the external circuit substrate. It is known that a terminal plating part such as Ni plating is provided on the surface of the terminal part from the viewpoint of preventing corrosion.

  The end of the terminal plating part is particularly susceptible to corrosion. Therefore, an attempt to devise the structure of the end portion of the terminal plating portion is known. For example, in FIG. 2 of Patent Document 1, the end surface of the wiring coating layer, the lower surface portion of the wiring coating layer that is separated from the wiring portion, the upper surface portion (inclined surface) of the wiring portion that is separated from the wiring coating layer, and the terminal portion A suspension substrate having a terminal covering portion formed so as to be in close contact with the surface is disclosed.

JP 2011-096721 A

  As described in FIG. 2 of Patent Document 1, even if the terminal covering portion is formed on the end surface of the wiring covering layer, the wiring covering layer itself is thin and usually has pores (small holes). Therefore, there is a problem that the terminal portion cannot be sufficiently protected. In particular, the terminal portion is likely to be gradually corroded during long-term use.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a suspension substrate in which corrosion of a terminal portion is prevented.

  In order to solve the above problems, in the present invention, a metal support substrate, an insulating layer formed on the metal support substrate, a wiring layer formed on the insulating layer, and formed on the wiring layer are formed. A suspension substrate having a wiring coating layer and a cover layer formed on the wiring coating layer, wherein the wiring layer includes a stepped portion formed on a surface on the cover layer side and the stepped portion. And the terminal portion is separated from the cover layer by the stepped portion, thereby exposing the surface of the cover layer on the wiring layer side. The suspension substrate is characterized in that a terminal plating portion having a single composition is formed on the surface of the terminal portion so as to cover the lower end portion of the cover layer.

In the above invention, the thickness direction of the difference between the lower end and the top surface of the terminal plating portions of the cover layer (H ₁₎ is preferably at 0.3μm or more. This is because it is possible to sufficiently suppress the outside air and liquid from entering the wiring coating layer and the generation of foreign matter (particles) derived from the cover layer.

  According to this invention, since the said terminal plating part is formed, it can be set as the board | substrate for suspensions which prevented the corrosion of the terminal part.

  In the said invention, it is preferable that the material of the said cover layer is a photosensitive material. It is because generation | occurrence | production of the foreign material (particle) originating in a cover layer can be suppressed effectively. When the material of the cover layer is a photosensitive material, the angle θ at the lower end of the cover layer tends to be smaller. This is because the solvent used together with the photosensitive material tends to remain on the surface of the cover layer on the wiring layer side (the bottom surface of the cover layer). Since the solvent tends to promote a photosensitive polymerization reaction (eg, polyimide formation), the photosensitive polymerization reaction tends to proceed on the bottom surface of the cover layer where it is difficult to remove the solvent. As a result, the lower end portion of the cover layer becomes very thin (for example, a nano-order tailing portion is formed) and foreign matter is likely to be generated. However, the present invention can effectively suppress the generation of the foreign matter. There are advantages.

  In the said invention, it is preferable that the said terminal plating part and the said wiring coating layer contain the same metal. This is because the adhesion between the two is improved and corrosion of the terminal portion can be further prevented.

  In the said invention, it is preferable that the said metal is Ni.

  In the said invention, it is preferable that the surface plating part is formed on the said terminal plating part.

  The present invention also provides a suspension comprising the above-described suspension substrate and a load beam provided on the surface of the suspension substrate on the metal support substrate side.

  According to the present invention, by using the suspension substrate described above, a suspension in which corrosion of the terminal portion is prevented can be obtained.

  The present invention also provides an element-equipped suspension comprising the above-described suspension and a recording / reproducing element disposed on the suspension.

  According to the present invention, by using the above-described suspension, it is possible to provide a suspension with an element in which corrosion of the terminal portion is prevented.

  The present invention also provides a hard disk drive having 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, a metal support substrate, an insulating layer formed on the metal support substrate, a wiring layer formed on the insulating layer, a wiring coating layer formed on the wiring layer, A suspension layer having a cover layer formed on the wiring covering layer, wherein the step is formed by etching the surface of the wiring layer on the cover layer side, and the step portion. A terminal that is formed continuously and is thinner than the other part, and that exposes the surface of the cover layer on the wiring layer side by separating the terminal part from the cover layer by the stepped part. A suspension plating board comprising: a portion forming step; and a terminal plating portion forming step of covering a lower end portion of the cover layer on the surface of the terminal portion and forming a terminal plating portion having a single composition. To provide a production method.

  According to the present invention, it is possible to obtain a suspension substrate in which corrosion of the terminal portion is prevented by performing the terminal portion forming step and the terminal plating portion forming step.

  The suspension substrate of the present invention has the effect of preventing corrosion of the terminal portion.

It is a schematic diagram which shows an example of the board | substrate for suspensions of this invention. It is the enlarged view to which the element mounting area | region for recording / reproducing in Fig.1 (a) was expanded. It is AA sectional drawing of FIG. It is a schematic sectional drawing explaining the terminal part in this invention. It is a schematic sectional drawing explaining the terminal part in this invention. It is a schematic diagram explaining the terminal part in this invention. It is a schematic diagram explaining the wiring layer in 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 an example of the manufacturing method of the board | substrate for suspensions by a subtractive method. It is a schematic sectional drawing which shows an example of the manufacturing method of the board | substrate for suspensions by an additive method.

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

A. Suspension Substrate The suspension substrate of the present invention includes a metal support substrate, an insulating layer formed on the metal support substrate, a wiring layer formed on the insulating layer, and a wiring formed on the wiring layer. A suspension substrate having a coating layer and a cover layer formed on the wiring coating layer, wherein the wiring layer is continuous from the step portion formed on the surface on the cover layer side. And the terminal portion is separated from the cover layer by the stepped portion, thereby exposing the surface of the cover layer on the wiring layer side, A terminal plating portion having a single composition is formed on the surface of the terminal portion so as to cover the lower end portion of the cover layer.

  FIG. 1 is a schematic view showing an example of a suspension substrate of the present invention. FIG. 1A is a schematic plan view of a suspension substrate, and FIG. 1B is a cross-sectional view taken along line AA in FIG. In FIG. 1A, for convenience, the description of the cover layer and the insulating layer is omitted. A suspension substrate 100 shown in FIG. 1A includes a recording / reproducing element mounting region 101 formed at one tip portion, an external circuit board connection region 102 formed at the other tip portion, and a recording / playback device. A plurality of wiring layers 103a to 103d for electrically connecting the element mounting region 101 and the external circuit board connection region 102 are provided. The wiring layer 103a and the wiring layer 103b are a pair of wiring layers. Similarly, the wiring layer 103c and the wiring layer 103d are also a pair of wiring layers. One of these two wiring layers is a wiring layer for writing (for recording and writing), and the other is a wiring layer for reading (for reproduction and reading). On the other hand, as shown in FIG. 1B, the suspension substrate 100 includes 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. And a cover layer 4 formed on the wiring layer 3.

  FIG. 2 is an enlarged view of the recording / reproducing element mounting area in FIG. In FIG. 2, four wiring layers 103a to 103d are arranged up to the vicinity of the recording / reproducing element mounting region 101 and are electrically connected to a recording / reproducing element (not shown). 3A is a cross-sectional view taken along the line AA in FIG. 2, and FIG. 3B is an enlarged view of FIG. 3A. As shown in FIGS. 3A and 3B, a wiring covering layer 5 is formed between the wiring layer 3 and the cover layer 4. The wiring layer 3 has a stepped portion 3a formed on the surface on the cover layer 4 side, and a terminal portion 3b formed continuously from the stepped portion 3a and thinner than the other portions. Further, when the terminal portion 3b is separated from the cover layer 4 by the stepped portion 3a, the surface 4a on the wiring layer 3 side of the cover layer 4 is exposed. In other words, the position of the step portion 3a is a position where the surface 4a of the cover layer 4 on the wiring layer 3 side is exposed. Moreover, the terminal plating part 6 which covers the lower end part 4b of the cover layer 4 is formed in the surface of the terminal part 3b. The terminal plating portion 6 is a single composition plating portion, and a surface plating portion 7 made of Au plating or the like is formed on the terminal plating portion 6. The terminal plating portion 6 is preferably thicker than the depth of the step portion 3a as a whole. Further, the wiring covering layer 5 is not formed on the terminal portion 3b side with respect to the step portion 3a.

  According to this invention, since the said terminal plating part is formed, it can be set as the board | substrate for suspensions which prevented the corrosion of the terminal part. Thus, by forming a terminal plating portion that is significantly thicker than before, outside air and liquid (for example, water used for environmental tests) cannot enter the wiring coating layer. As a result, corrosion of the terminal portion (wiring layer) due to the pores of the wiring covering layer can be prevented. In particular, the present invention has an advantage that the corrosion of the terminal portion during long-term use can be effectively prevented.

  Furthermore, according to this invention, since the terminal plating part is formed so that the lower end part of a cover layer may be covered, generation | occurrence | production of the foreign material (particle) originating in a cover layer can be suppressed. For example, when the end portion of the cover layer is very thin, there is a problem that foreign matters derived from the cover layer are generated when the suspension substrate is manufactured and used. On the other hand, according to this invention, since the lower end part (thin part) of a cover layer is covered with a terminal plating part, there exists an advantage that generation | occurrence | production of a foreign material can be suppressed.

  On the other hand, in FIG. 6 of Patent Document 1, a terminal covering portion 6 composed of a first layer 6a (for example, Ni plating portion) and a second layer 6b (for example, Au plating portion) is formed. However, the second layer 6b in Patent Document 1 is usually a thin layer using an Au plating portion, and there is a problem that outside air and liquid easily enter the wiring coating layer. Similarly, since the second layer 6b is a thin layer, there is a problem that it is difficult to suppress the generation of foreign matters (particles) derived from the cover layer. On the other hand, in this invention, there exists an advantage that said problem can be solved by forming a terminal plating part significantly thicker than before.

In addition, since thickening the terminal plating part is disadvantageous for the fine pitch of the terminal part, it is normal practice to increase the thickness of the terminal plating part (first layer 6a in Patent Document 1) as in the present invention. I have not been told. On the other hand, in the present invention, although it is somewhat disadvantageous with respect to the fine pitch of the terminal portion, there is an advantage that the above-described problem can be solved by thickening the terminal plating portion. Further, when the terminal plating portion is made thick, the strength of the terminal portion is improved, and there is an advantage that deformation of the terminal portion at the time of connection with the element (or at the time of detachment for reconnection) can be prevented. Conventionally, a solder ball bonding method is known as a method for connecting a terminal portion and an element. In recent years, a solder ball jet bonding method is being adopted as a connection method suitable for increasing the number of terminals. In the solder jet bonding method, since high heat is instantaneously applied to the terminal portion, an intermetallic compound may be formed between the terminal plating portion functioning as a barrier of the wiring layer and the solder. Therefore, if the terminal plating portion is thin, the barrier property of the terminal plating portion is lowered, and it may be difficult to prevent diffusion of a metal (for example, copper) constituting the wiring layer. On the other hand, in this invention, there exists an advantage that the barrier property of a terminal plating part can be maintained highly by making a terminal plating part thick.
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 functions as a support for the suspension substrate. The material of the metal support substrate is preferably a metal having a spring property, and specific examples include stainless steel. 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 formed on a metal support substrate. The material of the insulating layer is not particularly limited as long as it has insulating properties, and examples thereof include a resin. Examples of the resin include polyimide resin, polybenzoxazole resin, polybenzimidazole resin, acrylic resin, polyether nitrile resin, polyether sulfone resin, polyethylene terephthalate resin, polyethylene naphthalate resin, and polyvinyl chloride resin. Of these, polyimide resin is preferred. It is because it is excellent in insulation, heat resistance and chemical resistance. In addition, the material of the insulating layer may be a photosensitive material or a non-photosensitive material. The thickness of the insulating layer is, for example, preferably in the range of 5 μm to 30 μm, more preferably in the range of 5 μm to 18 μm, and still more preferably in the range of 5 μm to 12 μm.

  The wiring layer in the present invention is formed on the insulating layer. The material of the wiring layer is not particularly limited as long as it has conductivity, but for example, a metal can be cited, and copper (Cu) is particularly preferable. Moreover, the material of the wiring layer may be rolled copper or electrolytic copper. The thickness of the wiring layer is preferably in the range of 5 μm to 18 μm, for example, and more preferably in the range of 9 μm to 12 μm. Examples of the wiring layer in the present invention include a write wiring layer, a read wiring layer, a heat assist wiring layer, an actuator wiring layer, a ground wiring layer, a noise shield wiring layer, a power supply wiring layer, and a flight height control. Wiring layers for sensors, wiring layers for sensors, and the like.

  The wiring coating layer in the present invention is formed on the wiring layer. By providing the wiring covering layer, the metal constituting the wiring layer can be prevented from diffusing into the cover layer. Furthermore, the adhesion between the wiring layer and the cover layer can be improved. Although it does not specifically limit as a material of a wiring coating layer, For example, metals, such as Ni and Sn, and alloys, such as Sn-Cu, Sn-Bi, and Sn-Ag, can be mentioned. Moreover, it is preferable that the wiring coating layer is composed of plating. The thickness of the wiring coating layer is preferably in the range of 50 nm to 500 nm, for example, and more preferably in the range of 100 nm to 300 nm.

  The cover layer in the present invention is formed on the wiring coating layer. By providing the cover layer, deterioration (corrosion etc.) of the wiring layer can be prevented. Examples of the material for the cover layer include those described above as the material for the insulating layer, and among them, a polyimide resin is preferable. The material of the cover layer may be a photosensitive material or a non-photosensitive material.

2. Next, the configuration of the suspension substrate of the present invention will be described. The suspension substrate according to the present invention is characterized in that a specific terminal plating portion is formed on the surface of the terminal portion. Although it does not specifically limit as a terminal plating part, For example, Ni plating, Cu plating, etc. can be mentioned, Ni plating is especially preferable. In particular, in the present invention, it is preferable that the terminal plating portion and the wiring coating layer contain the same metal. This is because the adhesion between the two is improved and corrosion of the terminal portion can be further prevented. The metal is preferably Ni. Moreover, in this invention, it is preferable that the surface plating part is formed on the terminal plating part. This is because the electrochemical stability of the terminal portion can be further increased. Examples of the surface plating portion include Au plating and Ag plating. Among these, Au plating is preferable.

As shown in FIG. 4, the difference in the thickness direction of the top surface of the lower end portion 4b and the plating surface 6 of the cover layer 4 and H _1, the length between the lower end portion 4b of the wiring cover layer 5 and the cover layer 4 was the L _1, the depth of the stepped portion 3a and D _1, the thickness of the wiring cover layer 5 and T _1, the thickness of the surface plated layer 7 and T _2, the angle of the lower end portion 4b of the cover layer 4 ( When the angle of the side surface relative to the bottom surface is θ, H ₁ is preferably 0.3 μm or more, more preferably 0.5 μm or more, and further preferably 1.0 μm or more. If H ₁ is too small, it may be difficult for outside air and liquid to easily enter the wiring coating layer 5 and to suppress the generation of foreign substances (particles) derived from the cover layer. It is. Further, H ₁ may be greater than the thickness of the cover layer. For example, in the case where the terminal portions of the wiring layers, the distance between the terminal portions of the elements apart, is made larger than the cover layer H _1, it is possible to impart the height adjustment function in the plating surface, This is because a highly reliable connection can be performed. On the other hand, the upper limit of an H ₁ is not particularly limited, for example, 10 [mu] m. L ₁ is preferably in the range of 0.3 μm to 5 μm, for example, and more preferably in the range of 0.5 μm to 3 μm. This is because if L ₁ is too small, the wiring covering layer 5 may not be sufficiently removed, and if L ₁ is too large, the cover layer 4 may sink into the wiring layer 3 side.

D ₁ is preferably in the range of 0.5 μm to 8 μm, for example, and more preferably in the range of 1 μm to 4 μm. This is because if D ₁ is too small, the wiring covering layer 5 may not be sufficiently removed, and if D ₁ is too large, the mechanical strength of the terminal portion may be insufficient. T ₁ is preferably in the range of 50 nm to 500 nm, for example, and more preferably in the range of 100 nm to 300 nm. In the T ₁ is too small, since the metal constituting the wiring layers may not be able to sufficiently improve the adhesion of the possibilities and the wiring layer and the cover layer can not be sufficiently prevented from being diffused into the cover layer is there. This is because if T ₁ is too large, the diffusion preventing function and the adhesion improving function are not changed, and only the thickness is increased. T ₂ is preferably in the range of 0.5 μm to 4.0 μm, for example, and more preferably in the range of 0.5 μm to 2.0 μm.

  Moreover, (theta) is usually less than 90 degrees, it is preferable that it is 70 degrees or less, and it is more preferable that it exists in the range of 15 degrees-65 degrees. This is because the generation of foreign matter (particles) derived from the cover layer can be suppressed when θ is in the above range. When the cover layer material is a photosensitive material, θ tends to be smaller. This is because the solvent used together with the photosensitive material tends to remain on the surface of the cover layer on the wiring layer side (the bottom surface of the cover layer). Since the solvent tends to promote a photosensitive polymerization reaction (eg, polyimide formation), the photosensitive polymerization reaction tends to proceed on the bottom surface of the cover layer where it is difficult to remove the solvent. As a result, the lower end portion of the cover layer becomes very thin (for example, a nano-order tailing portion is formed) and foreign matter is likely to be generated. However, the present invention can effectively suppress the generation of the foreign matter. There are advantages.

  Further, the step portion 3a shown in FIG. 4 is composed of a wall portion parallel to the thickness direction, but the step portion in the present invention has a thickness as shown in FIG. 5 (a). It may be a stepped portion 3a composed of a wall portion having a predetermined angle with respect to the direction, or may be a stepped portion 3a composed of a curved wall portion as shown in FIG. 5 (b). good.

  The terminal portion in the present invention may be a head-side terminal portion used for connection to an element (recording / reproducing element, thermal assist element, actuator element), or used for connection to an external circuit board. The terminal portion on the tail side may be used. FIG. 6A is a schematic plan view showing an example of a terminal portion used for connection to an external circuit board, and FIG. 6B is a cross-sectional view taken along line AA of FIG. The terminal portions shown in FIGS. 6A and 6B are so-called flying lead type terminal portions, and are electrically connected to the terminal portions of the external circuit board by ultrasonic bonding or the like.

  The wiring layer in the present invention is formed on the insulating layer. In the present invention, “formed on the insulating layer” is a concept including not only the case of being formed so as to be in contact with the insulating layer but also the case of being formed through some layer between the insulating layer. is there. FIG. 7A is a so-called wiring laminate type suspension substrate, and FIG. 7B is a cross-sectional view taken along the line AA of FIG. As shown in FIG. 7B, the metal support substrate 1, the first insulating layer 2x, the first wiring layer 3x, the second insulating layer 2y, the second wiring layer 3y, and the cover layer 4 are formed in this order. The wiring layer in the present invention may be the first wiring layer 3x or the second wiring layer 3y.

B. Suspension Next, the suspension of the present invention will be described. The suspension according to the present invention includes a suspension substrate and a load beam provided on a surface of the suspension substrate on the metal support substrate side.

  FIG. 8 is a schematic plan view showing an example of the suspension of the present invention. A suspension 300 shown in FIG. 8 has the above-described suspension substrate 100 and a load beam 200 provided on the surface of the suspension substrate 100 on the metal support substrate side.

  According to the present invention, by using the suspension substrate described above, a suspension in which corrosion of the terminal portion is prevented can be obtained.

  The suspension of the present invention has at least a suspension substrate and a load beam. The suspension substrate in the present invention is the same as the content described in the above “A. Suspension substrate”, and therefore description thereof is omitted here. On the other hand, the load beam in the present invention is provided on the surface of the suspension substrate on the metal support substrate side. Although the material of the load beam is not particularly limited, for example, a metal can be used, and stainless steel is preferable.

C. 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 a recording / reproducing element disposed on the suspension.

  FIG. 9 is a schematic plan view showing an example of the suspension with an element of the present invention. The element-mounted suspension 400 shown in FIG. 9 includes the suspension 300 described above and the recording / reproducing element 301 mounted on the suspension 300 (recording / reproducing element mounting region 101 of the suspension substrate 100).

  According to the present invention, by using the above-described suspension, it is possible to provide a suspension with an element in which corrosion of the terminal portion is prevented.

  The suspension with an element of the present invention includes at least a suspension and a recording / reproducing element. The suspension according to the present invention is the same as the content described in “B. Suspension” above, and thus the description thereof is omitted here. The recording / reproducing element is not particularly limited, but preferably has a magnetic generating element. Specifically, a magnetic head slider can be mentioned.

D. Next, the hard disk drive of the present invention will be described. The hard disk drive of the present invention has the above-described suspension with an element.

  FIG. 10 is a schematic plan view showing an example of the hard disk drive of the present invention. A hard disk drive 500 shown in FIG. 10 includes the above-described suspension 400 with an element, a disk 401 on which data is written and read by the suspension 400 with an element, a spindle motor 402 that rotates the disk 401, and an element of the suspension 400 with an element. Arm 403 and voice coil motor 404, and a case 405 for sealing the above members.

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

  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. Since the suspension with an element is the same as the content described in “C. Suspension with an element”, description thereof is omitted here. As other members, the same members as those used in a general hard disk drive can be used.

E. Next, a method for manufacturing a suspension substrate according to the present invention will be described. The suspension substrate manufacturing method of the present invention includes a metal support substrate, an insulating layer formed on the metal support substrate, a wiring layer formed on the insulating layer, and a wiring formed on the wiring layer. A method of manufacturing a suspension substrate having a coating layer and a cover layer formed on the wiring coating layer, wherein a step portion is formed by etching the surface of the wiring layer on the cover layer side, and By forming a terminal portion that is continuously formed from the step portion and thinner than the other portions, and the terminal portion is separated from the cover layer by the step portion, the surface of the cover layer on the wiring layer side And a terminal plating portion forming step for covering the lower end portion of the cover layer and forming a terminal plating portion having a single composition on the surface of the terminal portion. A.

  According to the present invention, it is possible to obtain a suspension substrate in which corrosion of the terminal portion is prevented by performing the terminal portion forming step and the terminal plating portion forming step. The method for manufacturing a suspension substrate according to the present invention can be broadly divided into a manufacturing method by a subtractive method and a manufacturing method by an additive method.

1. Subtractive Method First, a manufacturing method using the subtractive method will be described. As an example of the manufacturing method by the subtractive method, a laminated member preparing step for preparing a laminated member in which a metal supporting member, an insulating member, and a conductor member are laminated in this order, and a wiring for forming a wiring layer by etching the conductor member A layer forming step, a wiring covering layer forming step for forming a wiring covering layer on the wiring layer, a cover layer forming step for forming a cover layer on the wiring covering layer, and etching the insulating member to form an insulating layer. By forming the insulating layer forming step to be formed and etching the surface of the wiring layer on the cover layer side, a stepped portion and a terminal portion that is continuously formed from the stepped portion and thinner than other portions are formed, And the terminal part formation process which exposes the surface by the side of the said wiring layer of the said cover layer by separating the said terminal part from the said cover layer by the said level | step-difference part, and the said terminal part of Covering the lower end of the cover layer on the surface, forming a terminal plating portion forming a single-component terminal plating portion, etching the metal support member, forming a metal support substrate, The manufacturing method which has can be mentioned.

  FIG. 11 is a schematic cross-sectional view showing an example of a method for manufacturing a suspension substrate by a subtractive method. In FIG. 11, first, a laminated member in which the metal supporting member 1A, the insulating member 2A, and the conductor member 3A are laminated in this order is prepared (FIG. 11A). Next, the conductive member 3A is patterned by wet etching to form the wiring layer 3 (FIG. 11B). Next, the wiring coating layer 5 is formed on the wiring layer 3 (FIG. 11C). Next, the cover layer 4 is formed on the wiring covering layer 5 (FIG. 11D). Next, wet etching is performed to provide an opening in the metal support member 1A (FIG. 11E).

Thereafter, the insulating member 2A is patterned by wet etching to form the insulating layer 2 (FIG. 11F). By etching the surface of the wiring layer 3 on the cover layer 4 side, a stepped portion 3a and a terminal portion 3b that is continuously formed from the stepped portion 3a and thinner than other portions are formed, and the stepped portion 3a By separating the terminal portion 3b from the cover layer 4, the surface 4a on the wiring layer 3 side of the cover layer 4 is exposed (FIG. 11 (g)). Next, the single-composition terminal plating portion 6 is formed on the surface of the terminal portion 3b so as to cover the lower end portion 4b of the cover layer 4, and the surface plating portion 7 is formed on the terminal plating portion 6 (FIG. 11 ( g)). Next, the outer shape of the metal support member 1A is processed to form the metal support substrate 1, and a suspension substrate is obtained.
Hereinafter, a method for manufacturing a suspension substrate by the subtractive method will be described step by step.

(1) Laminated member preparation step The laminated member preparation step is a step of preparing a laminated member having a metal supporting member, an insulating member formed on the metal supporting member, and a conductor member formed on the insulating member. It is.

  In the subtractive method, a metal supporting board is obtained by etching the metal supporting member of the laminated member, an insulating layer is obtained by etching the insulating member of the laminated member, and the conductive member of the laminated body is etched. A wiring layer is obtained. The laminated member may be a commercially available three-layer material, or may be obtained by sequentially forming an insulating member and a conductor member on a metal support member.

(2) Wiring layer formation process A wiring layer formation process is a process of etching the said conductor member and forming a wiring layer.

  Examples of the method for forming the wiring layer include a method in which a resist pattern is formed on a conductive member of a laminated member using a dry film resist (DFR) or the like, and the conductive member exposed from the resist pattern is wet-etched. Can do. The type of etching solution used for wet etching is preferably selected as appropriate according to the type of conductor member. For example, when the material of the conductor member is Cu, an iron chloride-based etching solution or the like can be used.

  In the subtractive method, the metal support member may be etched simultaneously with the etching of the conductor member. Examples of the etching of the metal support member include etching for forming an opening and a jig hole. Further, if necessary, at least a part of the processing performed in the metal support substrate forming step described later may be performed simultaneously with the etching of the conductor member.

(3) Wiring covering layer forming step The wiring covering layer forming step is a step of forming a wiring covering layer on the wiring layer.

  The method for forming the wiring coating layer is not particularly limited. For example, a resist pattern is formed on the wiring layer using a dry film resist (DFR) or the like, and the wiring layer is exposed from the resist pattern. And a method of performing electroless plating or strike plating.

(4) Cover layer forming step The cover layer forming step is a step of forming a cover layer on the wiring layer.

  The method for forming the cover layer is not particularly limited, and is preferably selected as appropriate according to the material of the cover layer. For example, when the material of the cover layer is a photosensitive material, a patterned cover layer can be obtained by exposing and developing the cover layer formed on the entire surface. In addition, when the cover layer material is a non-photosensitive material, a predetermined resist pattern is formed on the entire surface of the cover layer, and a portion exposed from the resist pattern is removed by wet etching. The cover layer can be obtained.

(5) Insulating layer forming step The insulating layer forming step is a step of etching the insulating member to form an insulating layer.

  Examples of the method for forming the insulating layer include a method of forming a resist pattern on the insulating member using a dry film resist (DFR) or the like, and wet etching the insulating member exposed from the resist pattern. . The type of etchant used for wet etching is preferably selected as appropriate according to the type of insulating member. For example, when the material of the insulating member is a polyimide resin, an alkaline etchant or the like can be used.

(6) Terminal part formation process A terminal part formation process is a terminal which is continuously formed from the level difference part and the level difference part by etching the surface of the wiring layer on the cover layer side, and thinner than other parts. Forming a portion and separating the terminal portion from the cover layer by the stepped portion, thereby exposing the surface of the cover layer on the wiring layer side.

  Examples of the method for forming the terminal portion include a method of forming a resist pattern on the wiring coating layer using a dry film resist (DFR) or the like, and wet etching the wiring coating layer exposed from the resist pattern. . The type of etchant used for wet etching is preferably selected as appropriate according to the types of the wiring coating layer and the conductor member. For example, when the material of the wiring coating layer is Ni, potassium ferricyanide or permanganate An alkaline etching solution containing, an acidic etching solution containing ceric ammonium nitrate and perchloric acid, or the like can be used.

(7) Terminal plating part formation process A terminal plating part formation process is a process which covers the lower end part of the said cover layer on the surface of the said terminal part, and forms the terminal plating part of a single composition.

  A method for forming the terminal plating portion is not particularly limited as long as a desired plating portion can be obtained. For example, an electrolytic plating method can be used. For example, when forming a terminal plating portion composed of Ni plating, examples of the electrolytic Ni plating bath used include a watt bath and a sulfamic acid bath. The plating conditions are not particularly limited, and desired conditions (plating time, applied voltage, etc.) may be selected. Furthermore, in this invention, it is preferable to perform the surface plating formation process which forms a surface plating part on a terminal plating part.

(8) Metal support board | substrate formation process A metal support board | substrate formation process is a process of etching the said metal support member and forming a metal support board | substrate. In this step, the outer shape of the metal support substrate is usually processed.

  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 stainless steel, an iron chloride-based etchant or the like can be used. .

2. Additive Method Next, a manufacturing method using the additive method will be described. As an example of the manufacturing method by the additive method, a metal support member preparing step of preparing a metal support member, an insulating layer forming step of forming an insulating layer on the metal support member, and a wiring layer on the insulating layer A wiring layer forming step to be formed; a wiring covering layer forming step for forming a wiring covering layer on the wiring layer; a cover layer forming step for forming a cover layer on the wiring covering layer; and the wiring on the cover layer side Etching the surface of the layer forms a stepped portion and a terminal portion that is formed continuously from the stepped portion and is thinner than other portions, and the terminal portion is separated from the cover layer by the stepped portion. A terminal portion forming step for exposing the surface of the cover layer on the wiring layer side, and an end for covering the lower end portion of the cover layer on the surface of the terminal portion and forming a terminal plating portion of a single composition A plating unit forming step, the metal support member by etching, the metal supporting board forming step of forming a metal supporting board, mention may be made of a manufacturing method having.

  FIG. 12 is a schematic cross-sectional view showing an example of a method for manufacturing a suspension substrate by the additive method. In FIG. 12, first, a metal support member 1A is prepared (FIG. 12 (a)). Next, a patterned insulating layer 2 is formed on the surface of the metal support member 1A (FIG. 12B). Next, the wiring layer 3 is formed on the insulating layer 2 (FIG. 12C). Next, the wiring coating layer 5 is formed on the wiring layer 3 (FIG. 12D). Next, the cover layer 4 is formed on the wiring covering layer 5 (FIG. 12E). Next, wet etching is performed to provide an opening in the metal support member 1A (FIG. 12F), and similarly wet etching is performed to provide an opening in the insulating layer 2 (FIG. 12G).

Thereafter, the surface of the wiring layer 3 on the cover layer 4 side is etched to form the stepped portion 3a and the terminal portion 3b that is continuously formed from the stepped portion 3a and thinner than the other portions, and the stepped portion By separating the terminal portion 3b from the cover layer 4 by 3a, the surface 4a on the wiring layer 3 side of the cover layer 4 is exposed (FIG. 12H). Next, the single-composition terminal plating part 6 is formed on the surface of the terminal part 3b so as to cover the lower end part 4b of the cover layer 4, and the surface plating part 7 is formed on the terminal plating part 6 (FIG. 12 ( i)). Next, the outer shape of the metal support member 1A is processed to form the metal support substrate 1, and a suspension substrate is obtained.
Hereinafter, a method for manufacturing a suspension substrate by the additive method will be described step by step.

(1) Metal support member preparation process A metal support member preparation process is a process of preparing a metal support member. For example, a commercially available metal support member can be used as the metal support member.

(2) Insulating layer forming step The insulating layer forming step is a step of forming an insulating layer on the metal support member.

  The method for forming the insulating layer is not particularly limited, and it is preferable to select appropriately according to the material of the insulating layer. For example, when the material of the insulating layer is a photosensitive material, a patterned insulating layer can be obtained by exposing and developing the insulating layer formed on the entire surface. In addition, when the material of the insulating layer is a non-photosensitive material, a predetermined resist pattern is formed on the surface of the insulating layer formed on the entire surface, and a portion exposed from the resist pattern is removed by wet etching to form a pattern. Insulating layer can be obtained.

(3) Wiring layer forming step The wiring layer forming step is a step of forming a wiring layer on the insulating layer.

  Examples of the method for forming the wiring layer include an electrolytic plating method. When the electrolytic plating method is used, it is preferable to form a seed layer on the surface of the insulating layer by sputtering or the like before forming the wiring layer.

(4) Other Steps The other steps are the same as those described in the manufacturing method using the subtractive method described above, and thus 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]
A first non-photosensitive polyimide was used as an insulating member forming material on a metal support member made of SUS304 having a thickness of 18 μm, and an insulating member having a thickness of 10 μm was formed by a coating method. Further, Ni—Cr—Cu serving as a seed layer is coated on the insulating member by sputtering to a thickness of about 300 nm, and a conductive member which is a Cu plating layer having a thickness of 9 μm is formed by Cu plating using the conductive layer as a conductive medium. (FIG. 11A) was obtained.

  Next, a resist pattern was obtained by patterning simultaneously using a dry film so that a jig hole whose positional accuracy is important on the SUS side and a desired wiring layer on the Cu plating layer side can be formed. Thereafter, wet etching was performed using a ferric chloride solution, and a resist film was removed after the etching. Thereby, a wiring layer was formed from the conductor member, and a jig hole was formed in the metal support member (FIG. 11B).

Thereafter, electroless Ni plating was performed in an acidic plating bath containing sodium hypophosphite as a reducing agent to form a wiring coating layer on the surface of the wiring layer (FIG. 11 (c)). Next, a photosensitive polyimide precursor was applied on the wiring coating layer, dried, and then exposed to a desired pattern shape through a mask using a high-pressure mercury lamp as a light source at an exposure amount of 500 to 2000 mJ / cm ² . . After that, heating is performed under such a condition that the maximum temperature reaches 280 ° C. to 350 ° C. and the maximum temperature holding time is within a range of 0.1 minutes to 60 minutes, and development is performed with an alkaline aqueous solution. The pattern image of was formed. Next, heating was performed in a nitrogen atmosphere to form a cover layer (FIG. 11D). Next, wet etching was performed to provide an opening in the metal support member (FIG. 11E).

  Thereafter, the insulating member 2A was patterned by wet etching to form the insulating layer 2 (FIG. 11 (f)). Next, resist plate making was performed to form a terminal portion, and a step portion and a terminal portion were formed by wet etching (FIG. 11G). Next, electrolytic Ni plating was performed to form a terminal plating portion on the terminal portion, and then electrolytic Au plating was performed to form a surface plating portion (FIG. 11 (h)). Finally, the outer shape of the metal support substrate was processed. As a result, a suspension substrate was obtained.

The cross-sectional dimensions of the terminal portion of the obtained suspension substrate are shown in FIG. 4 as H ₁ = 0.765 μm, L ₁ = 2.021 μm, D ₁ = 2.023 μm, and T ₁ = 145.1 nm and T ₂ = 748.1 nm.

[Example 2]
A metal support member made of SUS304 having a thickness of 18 μm was prepared (FIG. 12A). A photosensitive polyimide precursor was applied to a metal support member, dried, and then exposed to a desired pattern shape through a mask using a high-pressure mercury lamp as a light source at an exposure amount of 500 to 2000 mJ / cm ² . Thereafter, heating is performed under such conditions that the maximum temperature reaches 160 ° C. to 190 ° C. and the maximum temperature holding time is within a range of 0.1 minutes to 60 minutes, and development is performed with an alkaline aqueous solution. The pattern image of was formed. Thereafter, heating was performed in a nitrogen atmosphere to form an insulating layer. The thickness of the insulating layer formed on the metal support member was 10 μm (FIG. 12B). Next, a seed layer of Cr single layer was formed to 35 to 45 nm on the surface on the insulating layer side by sputtering. Next, resist plate making was performed, and a wiring layer was formed on the surface exposed from the resist pattern (FIG. 12C).

Thereafter, a wiring coating layer was formed on the surface of the wiring layer by Ni strike plating (FIG. 12D). Next, a photosensitive polyimide precursor was applied on the wiring coating layer, dried, and then exposed to a desired pattern shape through a mask using a high-pressure mercury lamp as a light source at an exposure amount of 500 to 2000 mJ / cm ² . . After that, heating is performed under such a condition that the maximum temperature reaches 280 ° C. to 350 ° C. and the maximum temperature holding time is within a range of 0.1 minutes to 60 minutes, and development is performed with an alkaline aqueous solution. The pattern image of was formed. Next, heating was performed in a nitrogen atmosphere to form a cover layer (FIG. 12E). Next, wet etching was performed to provide an opening in the metal support member (FIG. 12 (f)). Next, wet etching was performed to provide an opening in the insulating layer (FIG. 12G).

  Then, resist plate making was performed in order to form a terminal part, and the level | step-difference part and the terminal part were formed by wet etching (FIG.12 (h)). Next, electrolytic Ni plating was performed to form a terminal plating portion on the terminal portion, and then electrolytic Au plating was performed to form a surface plating portion on the terminal plating portion (FIG. 12 (i)). Finally, the outer shape of the metal support substrate was processed. As a result, a suspension substrate was obtained.

  DESCRIPTION OF SYMBOLS 1 ... Metal support substrate, 2 ... Insulating layer, 3 ... Wiring layer, 3a ... Step part, 3b ... Terminal part, 4 ... Cover layer, 4a ... Surface on the wiring layer side of cover layer, 4b ... Lower end part of cover layer, DESCRIPTION OF SYMBOLS 5 ... Wiring coating | coated part, 6 ... Terminal plating part, 7 ... Surface plating part, 100 ... Suspension board | substrate, 101 ... Recording / reproducing element mounting area | region, 102 ... External circuit board connection area | region, 103 ... Wiring layer

Claims (10)

A metal support substrate, an insulating layer formed on the metal support substrate, a wiring layer formed on the insulating layer, a wiring coating layer formed on the wiring layer, and formed on the wiring coating layer A suspension substrate having a cover layer,
The wiring layer has a step portion formed on the surface on the cover layer side, a terminal portion formed continuously from the step portion, and thinner than other portions,
When the terminal portion is separated from the cover layer by the stepped portion, the surface of the cover layer on the wiring layer side is exposed,
The vertex of the lower end portion of the cover layer protrudes from the wiring coating layer,
On the surface of the terminal part, covering the top of the lower end of the cover layer, a terminal plating part of a single composition is formed ,
The suspension substrate, wherein the terminal plating portion is generally thicker than the sum of the depth of the stepped portion and the thickness of the wiring coating layer . 2. The suspension substrate according to claim 1, wherein the terminal plating portion is 0.3 μm or more thicker than the sum of the depth of the stepped portion and the thickness of the wiring covering layer as a whole .   The suspension substrate according to claim 1 or 2, wherein a material of the cover layer is a photosensitive material.   The suspension substrate according to any one of claims 1 to 3, wherein the terminal plating portion and the wiring covering layer contain the same metal.   The suspension substrate according to claim 4, wherein the metal is Ni.   The suspension substrate according to any one of claims 1 to 5, wherein a surface plating portion is formed on the terminal plating portion.   A suspension comprising: the suspension substrate according to any one of claims 1 to 6; and a load beam provided on a surface of the suspension substrate on the metal support substrate side. .   8. A suspension with an element, comprising: the suspension according to claim 7; and a recording / reproducing element disposed on the suspension.   A hard disk drive comprising the suspension with an element according to claim 8. A metal support substrate, an insulating layer formed on the metal support substrate, a wiring layer formed on the insulating layer, a wiring coating layer formed on the wiring layer, and formed on the wiring coating layer And a cover layer, and a method for producing a suspension substrate comprising:
Etching the surface of the wiring layer on the cover layer side and the wiring covering layer to form a stepped portion and a terminal portion that is continuously formed from the stepped portion and is thinner than other portions; and The terminal that separates the terminal portion from the cover layer by the stepped portion, exposes the surface of the cover layer on the wiring layer side, and protrudes the apex of the lower end portion of the cover layer beyond the wiring covering layer Part forming step;
On the surface of the terminal part, covering the top of the lower end of the cover layer, a terminal plating part forming step of forming a terminal plating part of a single composition,
I have a,
The method of manufacturing a suspension substrate, wherein the terminal plating portion is entirely thicker than the sum of the depth of the stepped portion and the thickness of the wiring coating layer .

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