JP2013045485A - Substrate for suspension, suspension, suspension with head, hard disk drive, and method for manufacturing substrate for suspension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance mounting reliability of a magnetic head slider corresponding to a thermally assisted recording method.SOLUTION: A substrate for suspension has a magnetic head slider mounting region on which a magnetic head slider mounting a light-emitting element is mounted. The magnetic head slider mounting region includes a metal substrate 10 having an opening 10A to which the light-emitting element is inserted, an insulating layer 20 provided on the metal substrate so as to surround the opening, and a wiring layer 30 provided on the insulating layer. The wiring layer has a plurality of wires and terminals 32 which are connected to the ends of the respective wires, are arranged in the vicinity of the opening and are electrically connected to the magnetic head slider. The side face 32A and the upper face 32B in the light-emitting element side of the terminal are covered with a first metal layer 33. A second metal layer 34 having higher wettability of a solder than that of the first metal layer is provided on the upper face 33A of the first metal layer. At least the first metal layer in the side face side in the light-emitting element side is exposed to the outside.

Description

  The present invention relates to a suspension substrate, a suspension, a suspension with a head, a hard disk drive, and a method for manufacturing a suspension substrate. The present invention relates to a method for manufacturing a hard disk drive and a suspension board.

  In general, a hard disk drive (HDD) includes a suspension board on which a magnetic head slider for writing and reading data to and from a disk storing data is mounted. The suspension substrate has a plurality of wirings and a plurality of terminals for connection provided in the vicinity of the mounting area on which the magnetic head slider is mounted, and each terminal is connected to a corresponding wiring. These terminals are connected to slider pads of the magnetic head slider, respectively, so that data is transferred to the magnetic head slider (see, for example, Patent Document 1).

  By the way, in order to increase the recording density of the HDD, a magnetic head corresponding to a heat-assisted recording method, in which a laser diode (LD) element or a light emitting diode (LED) element (hereinafter simply referred to as “light emitting element”) is mounted on the back surface. A slider is known. Here, the heat-assisted recording method is a hard disk with a high density by reducing magnetic particles, and it is difficult to maintain at room temperature by instantaneously heating the part that performs magnetic recording with light from the light emitting element. This is a recording method that enables recording with high magnetic force.

  In a suspension substrate on which a magnetic head slider corresponding to such a heat-assisted recording method is mounted, a light emitting element is inserted into an opening provided in a metal substrate, and each terminal is connected to a slider pad of the magnetic head slider. The At this time, the side surface on the tip side of each terminal comes to face the side surface of the light emitting element. Gold plating is applied to the upper surface of the terminal and the side surface on the light emitting element side for soldering.

JP 2006-120288 A

  However, in the conventional suspension substrate, when soldering the upper surface of the terminal and the slider pad, the solder wraps around the side surface of the terminal on the light emitting element side. For this reason, the light emitting element of the magnetic head slider comes into contact with the surrounding solder. There is a possibility that the light emitting element in contact with the high temperature solder is damaged. In addition, after the solder is cured, a force is applied through the solder due to vibration or the like, so that the light emitting element may be damaged. As described above, in the conventional suspension substrate, the mounting reliability of the magnetic head slider corresponding to the heat-assisted recording method is lowered.

  The present invention has been made in consideration of such points, and the suspension substrate, the suspension, the suspension with the head, and the hard disk drive capable of improving the mounting reliability of the magnetic head slider corresponding to the heat-assisted recording method. It is another object of the present invention to provide a suspension substrate manufacturing method.

A suspension substrate according to an aspect of the present invention is provided.
A suspension substrate having a magnetic head slider mounting area on which a magnetic head slider mounted with a light emitting element is mounted,
The magnetic head slider mounting area is
A metal substrate having an opening through which the light emitting element is inserted;
An insulating layer provided around the opening on the metal substrate;
A wiring layer provided on the insulating layer,
The wiring layer has a plurality of wirings and terminals connected to the tips of the wirings and arranged in the vicinity of the openings and electrically connected to the magnetic head slider,
The side surface and the upper surface of the terminal on the light emitting element side are covered with a first metal layer,
A second metal layer having higher solder wettability than the first metal layer is provided on the upper surface of the first metal layer;
At least the first metal layer on the side surface on the light emitting element side is exposed to the outside.

In the suspension substrate,
The terminal of the wiring layer protrudes over the opening,
The insulating layer may have a plurality of protrusions that protrude from the opening and that support the terminals of the wiring layer and are spaced apart from each other.

In the suspension substrate,
Between the protrusions of the insulating layer may be an optical waveguide of the light emitting element.

In the suspension substrate,
The metal substrate may include a metal substrate body and a heat dissipating metal portion provided on a back surface of the protruding portion of the insulating layer and spaced apart from the metal substrate body.

In the suspension substrate,
The first metal layer is a nickel plating layer;
The second metal layer may be a gold plating layer.

A suspension according to an aspect of the present invention includes:
A base plate;
The suspension substrate attached to the base plate via a load beam.

A suspension with a head according to an aspect of the present invention is provided.
The suspension,
And the magnetic head slider mounted on the suspension.

A hard disk drive according to an aspect of the present invention includes:
A suspension with the head is provided.

A method for manufacturing a suspension substrate according to an aspect of the present invention includes:
A magnetic head slider mounting region on which a magnetic head slider on which the light emitting element is mounted is mounted, the magnetic head slider mounting region including a metal substrate having an opening through which the light emitting element is inserted, and the opening on the metal substrate; A method for manufacturing a suspension substrate, comprising: an insulating layer provided in an enclosed manner; and a wiring layer provided on the insulating layer,
Forming, on the wiring layer, a plurality of wirings and terminals connected to the tips of the wirings and arranged in the vicinity of the openings and electrically connected to the magnetic head slider;
Forming a first metal layer on a side surface and an upper surface of the terminal on the light emitting element side;
A second metal layer having higher solder wettability than the first metal layer is formed on the upper surface of the first metal layer so that at least the first metal layer on the side surface on the light emitting element side is exposed to the outside. And a step of performing.

In the method for manufacturing the suspension substrate,
The first metal layer includes a third metal layer and a fourth metal layer,
The step of forming the first metal layer includes
Forming the third metal layer on a side surface and an upper surface of the terminal on the light emitting element side;
Acid cleaning the upper surface of the third metal layer;
Forming the fourth metal layer on the upper surface of the acid-washed third metal layer with the same material as the third metal layer.

In the method for manufacturing the suspension substrate,
The first metal layer is a nickel plating layer;
The second metal layer may be a gold plating layer.

  According to the present invention, it is possible to improve the mounting reliability of the magnetic head slider corresponding to the heat-assisted recording method.

1 is a plan view of a suspension substrate according to a first embodiment of the present invention. It is a top view of the mounting area | region of the board | substrate for suspensions concerning the 1st Embodiment of this invention. FIG. 3 is an enlarged plan view of a region A in FIG. 2. It is sectional drawing along the BB line of FIG. It is a top view of the mounting area | region where the magnetic head slider based on the 1st Embodiment of this invention was mounted. It is sectional drawing along CC line of FIG. 1 is a plan view of a suspension according to a first embodiment of the present invention. 1 is a plan view of a suspension with a head according to a first embodiment of the present invention. 1 is a perspective view of a hard disk drive according to a first embodiment of the present invention. It is sectional drawing which shows the manufacturing method of the board | substrate for suspensions concerning the 1st Embodiment of this invention. FIG. 11 is a cross-sectional view illustrating the method for manufacturing the suspension substrate, continued from FIG. 10. It is a top view of the mounting area | region of the board | substrate for suspensions of a comparative example. It is sectional drawing along the DD line of FIG. It is sectional drawing along the EE line of FIG. FIG. 6 is an enlarged plan view of a mounting region of a suspension substrate according to a second embodiment of the present invention and a cross-sectional view taken along line FF. It is an enlarged plan view of the mounting area | region of the board | substrate for suspensions concerning the 3rd Embodiment of this invention. It is sectional drawing of the mounting area | region of the board | substrate for suspensions concerning the 4th Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the board | substrate for suspensions concerning the 4th Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual ones.

(First embodiment)
FIG. 1 is a plan view of a suspension substrate 1 according to an embodiment of the present invention. As shown in FIG. 1, the suspension substrate 1 includes a mounting area 2 on which a magnetic head slider 50 (see FIG. 5) on which a light emitting element 55 is mounted as viewed from above, an electrode pad 3, a mounting area 2, and an electrode. And a wiring layer 30 to which the pad 3 is connected. The wiring layer 30 has a plurality of wirings. FIG. 1 is a simplified plan view showing a suspension substrate 1. In FIG. 1, a plurality of wirings are indicated by a single line. Although two electrode pads 3 are shown in FIG. 1, the number of electrode pads 3 corresponding to the wiring is actually provided. The electrode pad 3 is used for connection between the suspension substrate 1 and an external circuit.

  The wiring layer 30 can transmit write data to a disk 103 (see FIG. 9) described later and read data from the disk 103.

  Next, the mounting area 2 will be described. First, the state where the magnetic head slider 50 is not mounted will be described, and the state where it is mounted will be described later.

  FIG. 2 is a plan view of the mounting region 2 of the suspension substrate 1 according to the first embodiment of the present invention. FIG. 3 is an enlarged plan view of region A in FIG. FIG. 3A is a diagram showing the front surface side, and FIG. 3B is a diagram showing the back surface side. 4 is a cross-sectional view taken along line BB in FIG.

  As shown in FIGS. 2 to 4, the magnetic head slider mounting region 2 includes a metal substrate 10 having an opening 10 </ b> A through which the light emitting element 55 is inserted, and an insulating layer 20 provided on the metal substrate 10 so as to surround the opening 10 </ b> A. And a wiring layer 30 provided on the insulating layer 20.

  The wiring layer 30 includes a plurality of wirings 31 including a reading wiring and a writing wiring, and a terminal 32 connected to the tip of each wiring 31. The plurality of terminals 32 are arranged in the vicinity of the opening 10A and are electrically connected to the magnetic head slider 50 as will be described later. In the present embodiment, the plurality of terminals 32 are arranged in one direction and project on the opening 10A toward the light emitting element 55 side. A distance d2 between two adjacent terminals 32 at one location is wider than a distance d1 between the other two adjacent terminals 32.

  As shown in FIG. 2, the wiring layer 30 includes a light emitting element wiring 35 and a light emitting element terminal 36 connected to the tip of each light emitting element wiring 35. The light emitting element terminal 36 is disposed on the opening 10A and is electrically connected to the light emitting element 55 as described later.

  As shown in FIGS. 3B and 4, the insulating layer 20 has a plurality of protruding portions 21 that protrude from the opening 10 </ b> A and support the terminals 32 of the wiring layer 30, which are separated from each other. As shown in FIG. 4, the side surface 32 </ b> A on the light emitting element 55 side of the terminal 32 protrudes from the side surface 20 </ b> A on the light emitting element 55 side of the protruding portion 21 of the insulating layer 20. However, the position of the side surface 20A may coincide with the side surface 32A, or may protrude from the side surface 32A. The width of the protruding portion 21 of the insulating layer 20 is substantially the same as the width of the terminal 32.

  With such a configuration, the insulating layer 20 is not provided between the two terminals 32 adjacent to each other at the interval d <b> 2, and the space 40 is formed.

  As shown in FIGS. 3A and 4, the side surface 32 </ b> A of the terminal 32 on the light emitting element 55 side, the upper surface 32 </ b> B, and the lower surface 32 </ b> C protruding from the protruding portion 21 are made of a nickel (Ni) plating layer (first Metal layer) 33.

  A gold (Au) plating layer (second metal layer) 34 having higher solder wettability than the nickel plating layer 33 is provided on the upper surface 33 </ b> A of the nickel plating layer 33. In the present embodiment, a recess 33B is provided as a part of the upper surface 33A of the nickel plating layer 33, and a gold plating layer 34 is provided on the recess 33B. As will be described later, such a configuration results from the manufacturing method.

  The gold plating layer 34 may be provided on the entire upper surface 33 </ b> A of the nickel plating layer 33. In this case, the position of the side surface 34A on the light emitting element 55 side of the gold plating layer 34 coincides with the side surface 33C of the nickel plating layer 33 on the light emitting element 55 side. However, at least the nickel plating layer 33 on the side surface 32A on the light emitting element 55 side is exposed outward. That is, the gold plating layer 34 is not provided on the side surface 33C of the nickel plating layer 33 on the light emitting element 55 side.

  In FIG. 2, the nickel plating layer 33, the gold plating layer 34, and a cover layer 70 described later are omitted for clarity of explanation.

  Next, a state where the magnetic head slider 50 is mounted in the mounting area 2 will be described.

  FIG. 5 is a plan view of the mounting area 2 on which the magnetic head slider 50 according to the first embodiment of the present invention is mounted. FIG. 6 is a cross-sectional view taken along the line CC of FIG. In FIG. 5, the nickel plating layer 33, the gold plating layer 34, and a cover layer 70 described later are omitted for clarity.

  As shown in FIGS. 5 and 6, a laser diode (LD) element or a light emitting diode (LED) element 55 (hereinafter simply referred to as “light emitting element 55”) is mounted on the back surface (lower surface) of the magnetic head slider 50. The magnetic head slider 50 is mounted on the mounting area 2 so that the light emitting element 55 passes through the opening 10A. As described above, the magnetic head slider 50 corresponding to the heat-assisted recording method is mounted on the suspension substrate 1 in the present embodiment. The light emitting element 55 has an optical waveguide 56, and the optical waveguide 56 is provided on the side surface of the magnetic head slider 50 on the terminal 32 side. At the time of writing data, the light emitted from the light emitting element 55 is guided to the optical waveguide 56 and irradiated to the disk 103 from the surface (upper surface) side of the magnetic head slider 50 to heat the disk 103. .

  As shown in FIG. 5, the space 40 between the protrusions 21 of the insulating layer 20 (that is, between the terminals 32) is an optical waveguide 56 of the light emitting element 55. The optical waveguide 56 may have an elliptical cylindrical shape as illustrated, or may be a space where light is simply guided.

  As shown in FIGS. 5 and 6, the gold plating layer 34 on the terminal 32 is electrically connected to the slider pad 51 provided on the side surface of the magnetic head slider 50 on the terminal 32 side by solder 60. In this way, the wiring 31 and the magnetic head slider 50 are electrically connected.

  The back surface of the magnetic head slider 50 is supported by a support portion 75 on the side opposite to the terminal 32 side. The upper surface of the support portion 75 has substantially the same height as the upper surface 33A of the nickel plating layer 33. The support portion 75 is provided on the additional insulating layer 27 provided on the metal substrate 10, the additional wiring layer 37 provided in an island shape on the additional insulating layer 27, and the additional insulating layer 27 and the additional wiring layer 37. Cover layer 70 formed. The additional wiring layer 37 may be an electrically connected wiring or an unconnected wiring (dummy wiring). Further, the additional insulating layer 27 may be provided integrally with the insulating layer 20 or may be provided separately.

  As shown in FIG. 6, the metal substrate 10 and the back surface of the magnetic head slider 50 are bonded to each other in a space 76 surrounded on three sides by the support portion 75, the back surface of the magnetic head slider 50, and the metal substrate 10. An adhesive member 61 for fixing the head slider 50 is provided. An adhesive, a conductive paste, solder, or the like can be used for the adhesive member 61. It is preferable to use a conductive material for the adhesive member 61 and connect it to a ground pad (not shown) on the back surface of the magnetic head slider 50.

  The back surface of the magnetic head slider 50 is also supported by the two light emitting element terminals 36 described above with reference to FIG. On the upper surface of the light emitting element terminal 36, a nickel plating layer and a gold plating layer are provided in this order. In addition, the light emitting element terminal 36 is electrically connected to a light emitting element pad (not shown) provided on the side surface of the light emitting element 55 using solder or the like (not shown).

  Next, each component of the suspension substrate 1 will be described.

  The electrode pad 3 includes, for example, a nickel plating layer formed on the wiring layer 30 and a gold plating layer formed on the nickel plating layer.

  The material of the metal substrate 10 is not particularly limited as long as it has desired conductivity, elasticity, and strength. For example, stainless steel, aluminum, beryllium copper, or other copper alloys are used. It is preferable to use stainless steel.

  The material of the wiring layer 30 and the additional wiring layer 37 is not particularly limited as long as it has a desired conductivity, but it is preferable to use copper (Cu). In addition to copper, any material having electrical characteristics similar to pure copper can be used.

  The material of the insulating layer 20 and the additional insulating layer 27 is not particularly limited as long as it has a desired insulating property. For example, it is preferable to use polyimide (PI).

  As a material of the cover layer 70, it is preferable to use a resin material, for example, polyimide (PI). The material of the cover layer 70 can be a photosensitive material or a non-photosensitive material.

  Next, the suspension 81 in the present embodiment will be described with reference to FIG. A suspension 81 shown in FIG. 7 is provided on the surface (lower surface) opposite to the suspension substrate 1 and the mounting area 2 of the suspension substrate 1 described above, and the above-described magnetic head slider 50 is attached to a disk 103 (described later). And a load beam 82 for holding against (see FIG. 9).

  Next, the suspension with head 91 in the present embodiment will be described with reference to FIG. A suspension 91 with a head shown in FIG. 8 has the above-described suspension 81 and a magnetic head slider 50 mounted on the mounting region 2 of the suspension substrate 1 and provided with a plurality of slider pads 51. As described above, the light emitting element 55 is mounted on the back surface of the magnetic head slider 50.

  Next, the hard disk drive 101 in this embodiment will be described with reference to FIG. A hard disk drive 101 shown in FIG. 9 is attached to a case 102, a disk 103 that is rotatably attached to the case 102, stores data, a spindle motor 104 that rotates the disk 103, and a desired flying height on the disk 103. And a suspension 91 with a head including a magnetic head slider 50 for writing and reading data to and from the disk 103. Of these, the suspension with head 91 is movably attached to the case 102, and a voice coil motor 105 for moving the magnetic head slider 50 of the suspension with head 91 along the disk 103 is attached to the case 102. . An arm 106 is connected between the suspension with head 101 and the voice coil motor 105.

[Method for Manufacturing Suspension Substrate 1]
Next, a method for manufacturing the suspension substrate 1 according to the present embodiment will be described. Here, as an example, a method of manufacturing the suspension substrate 1 by the subtractive method will be described with reference to FIGS. 10 and 11 correspond to the cross-sectional view of FIG. 4, but show a wider range on the wiring 31 side than FIG. 4. As a matter of course, the suspension substrate 1 can be manufactured not by the subtractive method but by the additive method.

  First, a laminate having the metal substrate 10, the insulating layer 20, and the wiring layer 30 is prepared (see FIG. 10A). In this case, first, a metal substrate 10 made of stainless steel having a thickness of about 20 μm is prepared, and the insulating layer 20 is formed on the metal substrate 10 by a coating method using non-photosensitive polyimide. Subsequently, nickel, chromium, and copper are sequentially coated on the insulating layer 20 by a sputtering method to form a seed layer (not shown) having a thickness of about 300 nm. Thereafter, a wiring layer 30 having a thickness of about 9 μm is formed by copper plating using this seed layer as a conductive medium. In this way, a laminate having the metal substrate 10, the insulating layer 20, and the wiring layer 30 is obtained.

  Subsequently, a plurality of wirings 31, terminals 32, light emitting element wirings 35, light emitting element terminals 36, electrode pads 3, and additional wiring layers 37 are formed in the wiring layer 30, and jig holes (not shown) are formed in the metal substrate 10. And the opening 10A is formed (see FIGS. 1, 2 and 10B). In this case, first, a patterned resist (not shown) is formed on the upper surface of the wiring layer 30 and the lower surface of the metal substrate 10 using a dry film resist by a photofabrication technique. Next, portions of the wiring layer 30 and the metal substrate 10 that are exposed from the resist are etched. Here, the method of etching the wiring layer 30 and the metal substrate 10 is not particularly limited, but it is preferable to perform wet etching. The etching solution is preferably selected as appropriate according to the type of material of the wiring layer 30 and the metal substrate 10. For example, when the material of the wiring layer 30 is copper and the material of the metal substrate 10 is stainless steel. As the etching solution, an iron chloride-based etching solution such as a ferric chloride aqueous solution can be used. After the etching is performed, the resist is removed.

  Next, a cover layer 70 covering the insulating layer 20 and the wiring 31 is formed on the insulating layer 20 and the wiring 31 (see FIG. 10C). In this case, first, non-photosensitive polyimide is coated on the insulating layer 20 and the wiring layer 30 using a die coater. Subsequently, the coated non-photosensitive polyimide is dried to form the cover layer 70. Next, a patterned resist (not shown) is formed on the formed cover layer 70. Subsequently, the cover layer 70 is developed and etched, and the etched cover layer 70 is cured to obtain the cover layer 70 having a desired shape. Thereafter, the resist is removed.

  After the cover layer 70 is formed, the insulating layer 20 is trimmed (see FIG. 10D). In this case, first, a patterned resist (not shown) is formed on the upper and lower surfaces of the insulating layer 20 and the upper surface of the cover layer 70. Subsequently, a portion of the insulating layer 20 exposed from the resist is etched, and the outer shape of the insulating layer 20 is processed into a pattern. Here, the method of etching the insulating layer 20 is not particularly limited, but it is preferable to perform wet etching. In particular, the etching solution is preferably selected as appropriate according to the type of material of the insulating layer 20. For example, when the insulating layer 20 is made of a polyimide resin, an alkaline etching solution such as an organic alkali etching solution is used. be able to. After the etching is performed, the resist is removed.

  After the outer shape of the insulating layer 20 is processed, nickel plating is applied to the terminal 32 (see FIG. 11A). In this case, after the plasma cleaning process on the surface of the terminal 32, a patterned resist (not shown) is formed on the upper and lower surfaces of the insulating layer 20 and the upper surface of the cover layer 70 again. Subsequently, a very thin nickel strike plating layer having a film thickness of 0.01 to 0.05 μm is formed on the surface of the terminal 32, and electrolytic nickel plating is performed using the nickel strike plating layer as a base. A standard nickel sulfamate plating bath is used as the electrolytic nickel plating bath, and electrolytic nickel plating is performed by electrolytic immersion plating (0.03 A, 2 minutes). Thereby, the nickel plating layer 33 is formed. After plating, the resist is removed.

  Next, after the nickel plating layer 33 is formed on the terminal 32, the nickel plating layer 33 is subjected to gold plating by an electrolytic plating method (see FIG. 11B). In this case, a patterned resist (not shown) is again formed on the upper and lower surfaces of the insulating layer 20, the upper surface of the cover layer 70, and the upper and lower surfaces 33A and 33C and 33D of the nickel plating layer 33. Subsequently, the upper surface 33 </ b> A of the nickel plating layer 33 exposed from the resist is subjected to acid cleaning. Thereby, a concave portion 33B is formed on the upper surface 33A of the nickel plating layer 33. Thereafter, electrolytic gold plating is performed. Thereby, the gold plating layer 34 is formed on the concave portion 33 </ b> B of the nickel plating layer 33. In the present embodiment, the gold plating layer 34 is formed by an electrolytic plating method. An example of a method for forming the gold plating layer 34 is a jig plating method. After plating, the resist is removed.

  The nickel plating layer 33 and the gold plating layer 34 are formed on the surface of the wiring layer 30 that is not covered by the cover layer 70. As described above, in the present embodiment, the nickel plating layer 33 and the gold plating layer 34 are applied to the terminals 32 and the light emitting element terminals 36 connected to the elements such as the magnetic head slider 50 and the electrode pads 3 connected to the external circuit. Is preferably formed. The type of plating is not particularly limited, and examples thereof include gold plating, nickel plating, silver (Ag) plating, and copper (Cu) plating. In particular, as in the present embodiment, it is preferable that the nickel plating layer 33 and the gold plating layer 34 are formed in this order from the surface side of the wiring layer 30. The thickness of the nickel plating layer 33 and the gold plating layer 34 is, for example, in the range of 0.1 μm to 4.0 μm.

  When the thicknesses of the nickel plating layer and the gold plating layer such as the electrode pad 3 are different from those of the nickel plating layer 33 and the gold plating layer 34 of the terminal 32, FIGS. After performing the terminal plating step shown in b), the terminal plating step shown in FIGS. 11A and 11B may be performed again on the electrode pad 3 and the like.

  Thereafter, the outer shape of the metal substrate 10 is processed (see FIG. 1). In this case, first, a patterned resist (not shown) is formed on the upper and lower surfaces of the metal substrate 10 using a dry film. Next, for example, a portion of the metal substrate 10 exposed from the resist is etched with an iron chloride-based etchant, and the metal substrate 10 is subjected to outer shape processing. Thereafter, the resist is removed. In this way, the suspension substrate 1 according to the present embodiment is obtained.

  A load beam 82 is attached to the lower surface of the suspension substrate 1 obtained in this way, and the suspension 81 shown in FIG. 7 is obtained. The magnetic head slider 50 on which the light emitting element 55 is mounted is mounted on the mounting area 2 of the suspension 81 to obtain a suspension 91 with a head shown in FIG. At this time, as shown in FIGS. 5 and 6, the light emitting element 55 is inserted into the opening 10A of the metal substrate 10, the lower surface of the magnetic head slider 50 is supported by the support portion 75 and the light emitting element terminal 36, and the magnetic head. The slider 50 is fixed to the metal substrate 10 by the adhesive member 61. The terminal 32 of the wiring layer 30 is electrically connected to the slider pad 51 of the magnetic head slider 50 by solder 60, and the light emitting element terminal 36 of the wiring layer 30 is connected to the light emitting element of the light emitting element 55 by solder. Electrically connected to the pad. Examples of the soldering method include an SBB (Solder Ball Bonding) method and an SJB (Solder Jet Bonding) method.

  Further, the suspension with head 91 is attached to the case 102 of the hard disk drive 101, and the hard disk drive 101 shown in FIG. 9 is obtained.

  Thus, according to the present embodiment, the side surface 32A and the upper surface 32B of the terminal 32 on the light emitting element 55 side are covered with the nickel plating layer 33, and the upper surface 33A of the nickel plating layer 33 is wetted by the solder from the nickel plating layer 33. A gold plating layer 34 having high properties is provided, and the nickel plating layer 33 on the side surface on the light emitting element 55 side is exposed to the outside. With this configuration, when the magnetic head slider 50 is mounted on the suspension substrate 1, the melted solder 60 adheres to the gold plating layer 34 and hardly adheres to the nickel plating layer 33. Accordingly, the melted solder 60 can be prevented from flowing (flowing) between the light emitting element 55 and the side surface 33C of the nickel plating layer 33. That is, it is possible to prevent the solder 60 from adhering to the light emitting element 55.

  Thereby, there is no possibility that the light emitting element 55 will be damaged by the heat of the solder 60. In addition, since the force is not applied to the light emitting element 55 through the solder 60 after the solder 60 is cured, the light emitting element 55 can be prevented from being damaged.

  Further, since the protruding portions 21 of the insulating layer 20 supporting the terminals 32 are separated from each other, the heat dissipation performance is improved. Therefore, the heat applied to the terminal 32 by the melted solder 60 is dissipated through the protruding portion 21 and the solder 60 is quickly cured, so that it further wraps around between the light emitting element 55 and the side surface 33C of the nickel plating layer 33. It becomes difficult. That is, it is possible to prevent the solder 60 from adhering to the light emitting element 55 more reliably.

  Furthermore, the optical waveguide 56 protruding from the side surface of the magnetic head slider 50 toward the terminal 32 can be disposed in the space 40 between the terminals 32. As a result, the magnetic head slider 50 can be disposed close to the terminal 32, so that the distance between the slider pad 51 of the magnetic head slider 50 and the gold plating layer 34 is shortened, and the solder 60 is more reliably connected to the light emitting element 55 and the nickel. It is possible to prevent sneaking between the side surface 33C of the plating layer. Further, positioning when mounting the magnetic head slider 50 on the suspension substrate 1 and fine adjustment of the position after mounting are facilitated.

  As described above, according to the present embodiment, the mounting reliability of the magnetic head slider 50 can be improved.

(Comparative example)
Here, a comparative example known by the inventor will be described.
FIG. 12 is a plan view of the mounting area of the suspension board of the comparative example. FIG. 12 is a diagram corresponding to FIG. 2 of the first embodiment. FIG. 13 is a cross-sectional view taken along the line DD of FIG. FIG. 14 is a cross-sectional view taken along line EE in FIG.

  As shown in FIG. 13, in the comparative example, the gold plating layer 34 also covers the nickel plating layer 33 on the side surface of the terminal 32 on the light emitting element 55 side. Accordingly, when the slider pad 51 of the magnetic head slider 50 and the gold plating layer 34 of the terminal 32 are soldered, the solder 60 flows through the side surface 34X of the gold plating layer 34 and the light emitting element 55 and the side surface 34X of the gold plating layer 34. Easily wrap around. Thereby, the solder 60 is cured in a state where it adheres to the light emitting element 55. For this reason, the light emitting element 55 that has contacted the high-temperature solder 60 may be damaged. Further, after the solder 60 is cured, a force is applied through the solder 60 due to vibration or the like, so that the light emitting element 55 may be damaged.

  As shown in FIGS. 12 and 14, in the comparative example, since the insulating layer 20 is provided between all the terminals 32, the optical waveguide 56 is in contact with the insulating layer 20 near the terminals 32. . Therefore, the distance between the magnetic head slider 50 and the terminal 32 is longer than that in the first embodiment, and the solder 60 is more likely to go around between the light emitting element 55 and the side surface 34X of the gold plating layer 34. Further, positioning when mounting the magnetic head slider 50 on the suspension board and fine adjustment of the position after mounting become difficult.

(Second Embodiment)
The second embodiment is different from the first embodiment in that the heat dissipating metal portion 12 is provided on the back surface of the protruding portion 21 of the insulating layer 20.

  FIG. 15A is an enlarged plan view (back view) of the mounting region 2 of the suspension substrate 1 according to the second embodiment of the present invention. FIG. 15A corresponds to the back view of FIG. FIG. 15B is a cross-sectional view taken along the line FF in FIG.

  As shown in FIGS. 15A and 15B, the metal substrate 10 includes a metal substrate body 11, a heat dissipating metal portion 12 provided on the back surface of the protruding portion 21 of the insulating layer 20, and separated from the metal substrate body 11. Have. In the present embodiment, the heat radiating metal portion 12 is provided on the entire back surface of the protruding portion 21, and is also provided on the back surface of the insulating layer 20 that is integrally provided on the base side of the protruding portion 21. However, the heat radiating metal portion 12 may be provided only on a part of the back surface of the protruding portion 21. Since other configurations are the same as those of the first embodiment of FIGS. 2 to 4, the same reference numerals are given to the same elements, and illustration and description thereof are omitted.

  As described above, according to the present embodiment, since the heat dissipating metal portion 12 is provided on the back surface of the protruding portion 21 of the insulating layer 20, the heat of the solder 60 is dissipated through the heat dissipating metal portion 21 during soldering. The Therefore, the heat dissipation is higher than that of the first embodiment, and the solder hardens more quickly. Therefore, the solder 60 can be more reliably prevented from entering between the light emitting element 55 and the side surface 33C of the nickel plating layer. That is, it is possible to prevent the solder 60 from adhering to the light emitting element 55 more reliably.

By the way, generally, the nickel plating layer 33 and the gold plating layer 34 are also formed on the side surface of the terminal 32 adjacent to the terminal 32. According to this embodiment, since each heat radiating metal part 12 is separated from the metal substrate body 11, it is assumed that the solder 60 is disposed on the side surface of the terminal 32 adjacent to the terminal 32 from the gold plating layer 34 on the upper surface of the terminal 32. Even if the gold plating layer 34 wraps around and adheres to the heat radiating metal portion 12, an electrical short circuit between the terminals 32 can be prevented.
Moreover, the same effect as 1st Embodiment is also acquired.

(Third embodiment)
The third embodiment is different from the first embodiment in that the insulating layer 20 that supports the terminal 32 is integrally provided.

  FIG. 16 is an enlarged plan view of the mounting region 2 of the suspension substrate 1 according to the third embodiment of the present invention. FIG. 16A is a view showing the front side corresponding to FIG. 3A, and FIG. 16B is a view showing the back side corresponding to FIG. 3B.

  As shown in FIGS. 16A and 16B, the insulating layer 20 that supports the terminal 32 is provided integrally. That is, the insulating layer 20 is also provided between the adjacent terminals 32. However, as in the first embodiment, a space 40 is provided between two adjacent terminals 32 at one location. Since other configurations are the same as those of the first embodiment of FIGS. 2 to 4, the same reference numerals are given to the same elements, and illustration and description thereof are omitted.

  As described above, according to the present embodiment, the insulating layer 20 that supports the terminal 32 is integrally provided and does not have the same number of protrusions as the number of the terminals 32. Is easy to manufacture. Also with this configuration, it is possible to prevent the solder 60 from entering between the light emitting element 55 and the side surface 33C of the nickel plating layer 33, as in the first embodiment. That is, it is possible to prevent the solder 60 from adhering to the light emitting element 55.

(Fourth embodiment)
The fourth embodiment differs from the first embodiment in the configuration of the nickel plating layer 33.

  FIG. 17 is a cross-sectional view of the mounting region 2 of the suspension substrate 1 according to the fourth embodiment of the present invention. As shown in FIG. 17A, the nickel plating layer 33 includes a first nickel plating layer (third metal layer) 38 and a second nickel plating layer (fourth metal layer) 39.

  Specifically, the second nickel plating layer 39 is provided in the recess 38 </ b> B provided on the upper surface 38 </ b> A of the first nickel plating layer 38, and the gold plating layer 34 is provided on the second nickel plating layer 39. . The upper surface 39A of the second nickel plating layer 39 is higher than the upper surface 38A of the first nickel plating layer 38.

  As shown in FIG. 17B, the upper surface 39A of the second nickel plating layer 39 may be substantially the same height as the upper surface 38A of the first nickel plating layer 38.

[Method for Manufacturing Suspension Substrate 1]
The manufacturing method of the suspension substrate 1 of the present embodiment is different from the first embodiment only in the step of forming the nickel plating layer 33. Hereinafter, the steps different from those of the first embodiment will be mainly described, and description of the same steps will be omitted.

  FIG. 18 is a cross-sectional view showing a method of manufacturing the suspension substrate 1 according to the fourth embodiment of the present invention. FIG. 18 corresponds to the cross-sectional view of FIG.

The step of forming the nickel plating layer 33 includes the following steps.
First, as described in the first embodiment with reference to FIG. 11A, after the insulating layer 20 is processed in outer shape, the terminals 32 are plated with nickel. Since a specific method is the same as that of the first embodiment, description thereof is omitted. Thereby, the 1st nickel plating layer 38 is formed in the side surface and upper surface at the side of the light emitting element 55 of the terminal 32 (refer Fig.11 (a)).

  Next, acid cleaning is performed on the upper surface 38A of the first nickel plating layer 38 (see FIG. 18A). In this case, a patterned resist (not shown) is formed on the upper and lower surfaces of the insulating layer 20, the upper surface of the cover layer 70, and the upper and lower surfaces 38A and 38C and 38D of the first nickel plating layer 38. Subsequently, the upper surface 38A of the portion of the first nickel plating layer 38 exposed from the resist is acid cleaned. As a result, a recess 38 </ b> B is formed on the upper surface 38 </ b> A of the first nickel plating layer 38.

  Next, nickel plating is performed on the upper surface of the acid-washed first nickel plating layer 38 (see FIG. 18B). In this case, an extremely thin nickel strike plating layer having a film thickness of 0.01 to 0.05 μm is formed in the recess 38B of the first nickel plating layer 38 exposed from the resist as in the first embodiment. Electrolytic nickel plating is performed on the strike plating layer. Thereby, the 2nd nickel plating layer 39 is formed in the recessed part 38B. That is, the nickel plating layer 33 including the first nickel plating layer 38 and the second nickel plating layer 39 is formed.

  Next, the second nickel plating layer 39 is subjected to gold plating by an electrolytic plating method (see FIG. 18C). In this case, electrolytic gold plating is performed on the second nickel plating layer 39 exposed from the resist as in the first embodiment. Thereby, the gold plating layer 34 is formed on the upper surface of the second nickel plating layer 39. After the gold plating, the resist is removed.

  Thus, according to the present embodiment, the second nickel plating layer 39 is further formed in the recess 38B of the first nickel plating layer 38 formed by the acid cleaning. Thereby, even when the first nickel plating layer 38 is excessively removed by acid cleaning and the upper surface of the terminal 32 is exposed, the gold plating layer 34 can be formed on the second nickel plating layer 39 formed thereafter. . Therefore, the reliability when forming the gold plating layer 34 can be improved.

If the gold plating is directly applied to the upper surface of the terminal 32 exposed by the acid cleaning, the gold plating layer 34 may not be formed on the exposed portion of the terminal 32. In this embodiment, such a state can be avoided.
Moreover, the same effect as 1st Embodiment is also acquired.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  For example, the light-emitting element 55 mounted on the magnetic head slider 50 is not limited to a laser diode element or a light-emitting diode element, and may be a laser diode element or a light source unit mounted with a light-emitting diode element. Other functional elements may be used as long as they can be heated.

  In each of the above embodiments, an example in which the first metal layer is a nickel plating layer and the second metal layer is a gold plating layer has been described, but the present invention is not limited thereto. That is, the second metal layer only needs to have higher solder wettability than the first metal layer. For example, the first metal layer may be a nickel plating layer and the second metal layer may be a gold-cobalt alloy plating layer. The first metal layer may be a nickel plating layer, and the second metal layer may be a tin plating layer. The first metal layer may be a nickel plating layer, and the second metal layer may be a tin-nickel alloy plating layer. Further, the first metal layer may be a nickel plating layer, and the second metal layer may be a tin-cobalt alloy plating layer. Also by these, the same effect as the above-described embodiments can be obtained.

DESCRIPTION OF SYMBOLS 1 Suspension board | substrate 2 Mounting area | region 3 Electrode pad 10 Metal substrate 10A Opening 11 Metal substrate main body 12 Thermal radiation metal part 20 Insulating layer 20A Side surface 21 Projection part 27 Additional insulating layer 30 Wiring layer 31 Wiring 32 Terminal 32A Side surface 32B Upper surface 32C Lower surface 33 Nickel Plating layer (first metal layer)
33A Upper surface 33B Recess 33C Side surface 34 Gold plating layer (second metal layer)
34A Side surface 35 Light emitting element wiring 36 Light emitting element terminal 37 Additional wiring layer 38 First nickel plating layer (third metal layer)
39 Second nickel plating layer (fourth metal layer)
40 Space 50 Magnetic head slider 51 Slider pad 55 Light emitting element 56 Optical waveguide 60 Solder 61 Adhesive member 70 Cover layer 75 Support portion 76 Space 81 Suspension 82 Load beam 91 Suspension with head 101 Hard disk drive 102 Case 103 Disc 104 Spindle motor 105 Voice coil Motor 106 arm

Claims (11)

A suspension substrate having a magnetic head slider mounting area on which a magnetic head slider mounted with a light emitting element is mounted,
The magnetic head slider mounting area is
A metal substrate having an opening through which the light emitting element is inserted;
An insulating layer provided around the opening on the metal substrate;
A wiring layer provided on the insulating layer,
The wiring layer has a plurality of wirings and terminals connected to the tips of the wirings and arranged in the vicinity of the openings and electrically connected to the magnetic head slider,
The side surface and the upper surface of the terminal on the light emitting element side are covered with a first metal layer,
A second metal layer having higher solder wettability than the first metal layer is provided on the upper surface of the first metal layer;
The suspension substrate, wherein at least the first metal layer on the side surface on the light emitting element side is exposed to the outside. The terminal of the wiring layer protrudes over the opening,
2. The suspension substrate according to claim 1, wherein the insulating layer has a plurality of protruding portions that protrude from the opening and support the terminals of the wiring layer and are spaced apart from each other. The suspension substrate according to claim 2, wherein a space between the protruding portions of the insulating layer serves as an optical waveguide of the light emitting element. The metal substrate includes: a metal substrate body; and a heat dissipating metal portion provided on a back surface of the projecting portion of the insulating layer and spaced from the metal substrate body. The suspension substrate described. The first metal layer is a nickel plating layer;
The suspension substrate according to any one of claims 1 to 4, wherein the second metal layer is a gold plating layer. A base plate;
The suspension board according to any one of claims 1 to 5, wherein the suspension board is attached to the base plate via a load beam. A suspension according to claim 6;
A suspension with a head, comprising: the magnetic head slider mounted on the suspension. A hard disk drive comprising the suspension with a head according to claim 7. A magnetic head slider mounting region on which a magnetic head slider on which the light emitting element is mounted is mounted, the magnetic head slider mounting region including a metal substrate having an opening through which the light emitting element is inserted, and the opening on the metal substrate; A method for manufacturing a suspension substrate, comprising: an insulating layer provided in an enclosed manner; and a wiring layer provided on the insulating layer,
Forming, on the wiring layer, a plurality of wirings and terminals connected to the tips of the wirings and arranged in the vicinity of the openings and electrically connected to the magnetic head slider;
Forming a first metal layer on a side surface and an upper surface of the terminal on the light emitting element side;
A second metal layer having higher solder wettability than the first metal layer is formed on the upper surface of the first metal layer so that at least the first metal layer on the side surface on the light emitting element side is exposed to the outside. And a step of manufacturing the suspension substrate. The first metal layer includes a third metal layer and a fourth metal layer,
The step of forming the first metal layer includes
Forming the third metal layer on a side surface and an upper surface of the terminal on the light emitting element side;
Acid cleaning the upper surface of the third metal layer;
The suspension substrate according to claim 9, further comprising: forming the fourth metal layer on the upper surface of the acid-cleaned third metal layer with the same material as the third metal layer. Production method. The first metal layer is a nickel plating layer;
The method for manufacturing a suspension substrate according to claim 9 or 10, wherein the second metal layer is a gold plating layer.

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