JP5849386B2 - Suspension substrate, method for manufacturing suspension substrate, suspension, suspension with element, and hard disk drive - Google Patents

Description

  The present invention relates to a suspension substrate that is excellent in slider mountability and free from solder shorts.

  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. For this reason, higher functions are also required for suspension substrates (flexures) used in HDDs.

In the suspension substrate, a slider (magnetic head) for reading data from the hard disk is connected to the slider mounting area.
As a method for connecting such a slider, a method is used in which a solder pad portion of a suspension board and a terminal provided on a side surface of the slider are connected by solder or gold balls. However, since various functions are provided on the suspension substrate and the slider in order to improve the HDD performance, the number of connection terminals is inevitably increased. As a result, the mounting difficulty level and the complexity of the slider structure are increasing. In order to solve this problem, a slider and a suspension substrate in a surface mounting form in which connection terminals are arranged on a contact surface of the slider with the suspension substrate have been proposed (for example, Patent Document 1).

  However, in such a surface mounting configuration, in the slider mounting area of the suspension board, the connection wiring connecting the slider mounting area and the external terminal portion, the solder pad soldered to the slider, the via wiring layer, etc. When the conductor layer, the plating layer formed on the surface of the conductor layer, and the thickness of the cover layer cause problems such as tilting of the slider, the mountability is reduced, or the slider is attached to the suspension substrate. There is a possibility that a short circuit may occur due to the flow of solder.

JP 2008-159245 A

  The present invention has been made in view of the above problems, and has as its main object to provide a suspension substrate that is excellent in slider mountability and free from solder shorts.

  In order to solve the above problems, the present invention provides a metal substrate, a base insulating layer formed on the metal substrate, a slider mounting region formed on the base insulating layer, and the opposite side of the slider mounting region. And a conductor layer having at least a connection wiring for connecting an external terminal portion disposed at an end of the suspension board, wherein the slider mounting region has a through hole formed in the base insulating layer. A via made of a conductive material for connecting the metal substrate and the via wiring is formed, and the conductor layer in the slider mounting region is connected to the connection wiring or the via wiring, via solder. Solder pads for connecting to the slider are formed, and the mounting area is formed on the conductor layer so as to surround the solder pads. A dry film resist layer made of a dry film resist is disposed, and the dry film resist layer has a film thickness thicker than the via, and a slider disposed on the dry film resist layer is disposed on the metal substrate. And a suspension substrate characterized in that the suspension substrate is disposed in a position to be kept parallel to each other.

  According to the present invention, by having the above-mentioned dry film resist layer, the slider mounting region of the suspension substrate can be made excellent in flatness, and the slider mounting property can be made excellent. it can. In addition, it is possible to prevent the solder from flowing out from a predetermined region to other places, and it is possible to prevent a solder short.

In the present invention, the dry film resist is preferably made of a photosensitive polyimide resin.
This is because the shape and the like of the dry film resist layer can be formed with high accuracy.

  In this invention, it is preferable to have a cover layer formed so that the said conductor layer may be covered. By covering the conductor layer in the region not covered with the dry film resist layer, the formation area of the plating layer can be reduced, and the cost can be reduced.

  In the present invention, the dry film resist layer is preferably formed so as to cover the via. This is because the flatness can be improved.

  In the present invention, it is preferable that a solder is laminated on the solder pad. This is because the mounting of the slider can be facilitated.

  The present invention provides a suspension including a suspension substrate.

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

  The present invention also provides a suspension with an element, characterized by having the above-described suspension and an element (slider) mounted in a slider mounting region of the suspension.

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

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

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

  The present invention relates to a metal substrate, a base insulating layer formed on the metal substrate, a slider mounting region formed on the base insulating layer, and an external portion disposed on the opposite end of the slider mounting region. A conductor layer having at least a connection wiring for connecting the terminal portion, and the slider mounting region is filled in a through-hole formed in the base insulating layer, and the metal substrate and the via wiring are connected to each other. A via made of a conductive material to be connected is formed, and a solder pad for connecting to the connection wiring or the via wiring and connecting to the slider via solder is formed on the conductor layer in the slider mounting region. Further, the mounting region is provided with a dry film resist made of a dry film resist disposed on the conductor layer and formed so as to surround the solder pad. The dry film resist layer has a thickness greater than that of the via, and is disposed at a position that keeps the slider disposed on the dry film resist layer parallel to the metal substrate. A method for manufacturing a suspension substrate, comprising: a multilayer substrate preparation step of preparing a multilayer substrate having the metal substrate, a base insulating layer, a conductor layer, and a via; and the dry film resist on the multilayer substrate, the solder pad Manufacturing a suspension substrate, characterized by having a dry film resist layer forming step of forming the dry film resist layer by exposing and developing the dry film resist after pasting so as to cover the conductor layer and the via Provide a method.

  According to the present invention, by having the dry film resist layer forming step, a suspension substrate having excellent flatness can be easily obtained.

  The present invention is advantageous in that it can provide a suspension substrate that is excellent in slider mountability and free from solder shorts.

It is a schematic plan view which shows an example of the board | substrate for suspensions of this invention. It is a schematic plan view which shows an example of the terminal formation part in this invention, and its vicinity. It is the sectional view on the AA line of FIG. FIG. 3 is a cross-sectional view taken along line AA when a slider is mounted on the suspension substrate illustrated in FIG. 2. It is a schematic plan view which shows the other example of the board | substrate for suspensions of this invention. It is a schematic plan view which shows the other example of the board | substrate for suspensions of this invention. It is a schematic plan view which shows the other example of the board | substrate for suspensions of this invention. It is a schematic plan view which shows the other example of the board | substrate for suspensions of this invention. It is a schematic plan view which shows the other example of the board | substrate for suspensions of this invention. It is a schematic plan view which shows the other example of the board | substrate for suspensions of this invention. It is a schematic plan view which shows the other example of the board | substrate for suspensions of this invention. It is a schematic sectional drawing which shows the other example of the board | substrate for suspensions of this invention. It is process drawing which shows an example of the manufacturing method of the board | substrate for suspensions of this invention. It is a schematic plan view which shows an example of the 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.

The present invention relates to a suspension board, a suspension using the same, a suspension with an element and a hard disk drive, and a method of manufacturing the same.
The suspension substrate, suspension substrate manufacturing method, suspension, suspension with element, and hard disk drive of the present invention will be described in detail below.

A. First, the suspension substrate of the present invention will be described.
The suspension substrate of the present invention is formed on the metal substrate, the base insulating layer formed on the metal substrate, the base insulating layer, and the slider mounting region and the end opposite to the slider mounting region. A suspension substrate having at least a connection layer for connecting the arranged external terminal portion, wherein the slider mounting region is filled in a through-hole formed in the base insulating layer. A via made of a conductive material for connecting the metal substrate and the via wiring is formed, and the conductor layer in the slider mounting region is connected to the connection wiring or the via wiring and connected to the slider via solder. A solder pad is formed on the conductive layer, and the solder pad is formed so as to surround the solder pad. A dry film resist layer made of a dry film resist is disposed. The dry film resist layer has a thickness greater than that of the via, and a slider disposed on the dry film resist layer is parallel to the metal substrate. It is arrange | positioned in the position kept at this.

Such a suspension substrate of the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan view showing an example of the suspension substrate of the present invention. A suspension substrate 10 shown in FIG. 1 includes a slider mounting region 20 formed at one end portion, an external terminal portion disposed at an end opposite to the slider mounting region 20, the external terminal portion, And a connection wiring 3c for connecting the slider mounting region 20.
2 is a schematic plan view showing the vicinity of the slider mounting area 20 of FIG. 1, and FIG. 3 is a cross-sectional view taken along line AA of FIG.

As illustrated in FIGS. 1 to 3, the suspension substrate 10 of the present invention includes a metal substrate 1, a base insulating layer 2 formed on the metal substrate 1, and a slider mounting region 20 of the base insulating layer 2. And a connection wiring 3c for connecting the external terminal portion, and the slider mounting region 20 is filled in a through-hole formed in the base insulating layer 2, and the metal substrate 1 and via wiring A via 5 made of a conductive material for connecting 3b is formed, and the conductor layer in the slider mounting region 20 is connected to the connection wiring 3c or the via wiring 3b and is connected to the slider via solder. Solder pads 3a are formed. Further, the mounting region 20 is made of a dry film resist disposed on the conductor layer and formed so as to surround the solder pads 3a. The dry film resist layer 6 is disposed, the dry film resist layer 6 is thicker than the via 5, and a slider disposed on the dry film resist layer 6 is disposed on the metal substrate 1. It is arranged at a position to keep parallel.
In this example, the solder pad 3 a is covered with a plating layer 8, and the conductor layer (connection wiring 3 c) is covered with a cover layer 7.
In FIG. 1 and FIG. 2, the description of the cover layer, the dry film resist layer, and the plating layer is omitted for ease of explanation.

FIG. 4 is a cross-sectional view taken along line AA when the slider (element) 41 is mounted on the dry film resist layer 6 of the suspension substrate 10 shown in FIG. In this example, the suspension substrate 10 and the slider 41 are connected by the solder 21 disposed on the solder pad 3 a of the suspension substrate 10.

According to the present invention, since the dry film resist layer is a dry film resist, when the dry film resist is applied by thermocompression bonding, the variation in height of each component such as the conductor layer and via is absorbed. Can do. For this reason, the slider mounting region of the suspension substrate can be made excellent in flatness. Therefore, when mounting a surface mount type slider on which a connection terminal with the suspension board formed on the contact surface with the suspension board is mounted, it is possible to prevent the slider from being tilted. It can be made excellent.
In addition, as described above, the dry film resist layer can absorb the variation in the height of each component, so that the thickness management of each component can be facilitated and the manufacturing difficulty of the suspension substrate can be reduced, and the yield can be reduced. Improvements can be made.
Further, when the dry film resist layer surrounds the solder pad, that is, when the solder pad and the slider are connected by solder by having a through hole that exposes the solder pad, It is possible to prevent the solder from flowing out and causing a short circuit with a terminal that should not be connected. In this way, it is possible to prevent the solder from flowing out from a predetermined region to other places, and it is possible to prevent a solder short.

The suspension substrate of the present invention has at least the dry film resist layer, metal substrate, base insulating layer, conductor layer, and via.
Hereinafter, each configuration of the suspension substrate of the present invention will be described in detail.

1. Dry Film Resist Layer The dry film resist layer in the present invention is made of a dry film resist that is disposed on the conductor layer in the mounting area and is formed so as to surround the solder pad. Further, the slider having a thickness larger than that of the via and disposed on the dry film resist layer is disposed at a position to keep the slider parallel to the metal substrate.
Here, parallel means that the slider can read the data on the hard disk with high accuracy when the suspension board on which the slider is mounted is used as a hard disk drive. is there.
Specifically, it indicates that the flatness of the surface of the dry film resist layer is 15 μm or less, and in the present invention, it is preferably 5 μm or less. This is because data can be read and written more stably.
In addition, about the said flatness, it can obtain | require by the method prescribed | regulated to JISB0621.

(1) Dry film resist The dry film resist layer used in the present invention comprises a dry film resist.
Such a dry film resist (hereinafter sometimes referred to as DRF) may be any resin having a desired heat resistance and a photosensitive property. It is also possible to use those commonly used for suspension substrate applications. Specific examples include polyimide DFR and epoxy DFR.

  The elastic modulus of the dry film resist used in the present invention is not particularly limited as long as warpage during heating can be prevented, but specifically, 0.15 GPa to 3.5 GPa. It is preferable to be within the range, and it is particularly preferable to be within the range of 0.15 GPa to 0.5 GPa. This is because, when the elastic modulus is within the above-described range, the warp or the like can be reduced.

As the film thickness of the dry film resist used in the present invention, the dry film resist layer can be made flat even when the conductor layer is covered, so long as it is thicker than the via. Although it does not specifically limit, Specifically, it can be in the range of 25 micrometers-50 micrometers.

(2) Dry film resist layer The position at which the dry film resist layer used in the present invention is disposed includes at least a slider mounting region and can be any position that can keep the slider parallel to the metal substrate. It is not particularly limited.
Such a position is appropriately set according to the shape of the slider and the like. For example, as illustrated in FIG. 5, the slider is a region that is in contact with the slider of the suspension substrate in plan view. As shown in FIG. 7, the conductor layer (connection wiring) in the slider mounting area, as shown in FIG. 7, is the entire surface excluding the area surrounding the solder pad in the mounting area, and only the periphery of the solder pad in the slider mounting area. 8 and the positions covering the vias, as shown in FIG. 8, in addition to the positions covering the conductor layers and vias in the slider mounting area, the outer peripheral portion of the slider mounting area, illustrated in FIGS. 9 and 10 Thus, in addition to the portion covering the conductor layer and the via, a part of the outer peripheral portion of the slider mounting region, and further, as illustrated in FIG. It can be a portion for covering a portion of the conductor layer formed on other than Ida mounting region.
5 to 11 indicate the same members as those in FIGS. 2 to 3, and a description thereof will be omitted here.
In the present invention, in particular, in a plan view, it is preferably a position excluding a region surrounding the solder pad in the slider mounting region and including at least the slider bottom area of the slider mounting region. The slider mounting area is preferably the same area as the slider bottom area except for the area surrounding the solder pad. This is because the slider can be stably kept parallel. Further, when the dry film resist layer is formed at a position other than the above-described positions, the flexibility of the suspension substrate of the present invention is reduced, and stable data reading is possible when used in a hard disk drive. This is because it may be difficult.

The plan view shape of the dry film resist layer used in the present invention has a shape surrounding the solder pad, that is, a through hole provided so that the solder pad is exposed.
As such a plan view shape of the dry film resist layer, for example, it may have an opening through which the via is exposed.
In the present invention, in particular, it is preferable that the via is exposed so as not to have an opening, that is, so as to cover the via. This is because the flatness can be improved. Further, it is possible to prevent problems such as contact of the via with the slider.

  Further, the size of the through hole through which the solder pad is exposed in plan view may be wider than the solder pad, that is, all the solder pads may be exposed in plan view. Narrower than that, that is, a part of the solder pad exposed may be used.

The thickness of the dry film resist layer used in the present invention is not particularly limited as long as it is larger than the thickness of the via and can keep the slider in parallel.
In the present invention, the via is preferably thicker in the range of 1 μm to 50 μm, more preferably in the range of 3 μm to 30 μm, and particularly preferably in the range of 5 μm to 15 μm. This is because it is easy to make the surface of the dry film resist layer in contact with the slider parallel to the metal substrate and flat. Further, when the solder pad is solder-connected to the connection terminal of the slider, it is possible to sufficiently suppress the outflow of solder and to reduce the occurrence of solder shorts.

  The dry film resist layer forming method used in the present invention is not particularly limited as long as it is a method capable of forming a dry film resist layer having a desired pattern. A method of exposing and developing after bonding a dry film resist can be used.

2. Metal substrate The metal substrate used in the present invention supports the base insulating layer, the conductor layer, the via, and the dry film resist layer.
The material for such a metal substrate is not particularly limited, but is preferably a metal having a spring property, and specific examples thereof include SUS.
In addition, the thickness of the metal substrate used in the present invention varies depending on the type of the material, but can be in the range of 10 μm to 20 μm, for example.

  The method for forming a metal substrate used in the present invention is not particularly limited as long as it can obtain a metal substrate having a desired pattern, and a method generally used for a suspension substrate should be used. Can do. Specifically, a method of patterning by etching using a resist can be used.

3. Base insulating layer The base insulating layer used in the present invention is formed on the metal substrate.

  The material of the base insulating layer is not particularly limited as long as it can prevent a short circuit between the metal substrate and the conductor layer, and usually has an insulating property such as polyimide resin (PI). Resins can be mentioned. The material of the base insulating layer may be a photosensitive material, but is preferably a non-photosensitive material. This is because the range of material selection can be widened. In addition, the non-photosensitive material has a low hygroscopic expansion coefficient and can generate less warpage.

  Further, the thickness of the base insulating layer is not particularly limited as long as it can prevent a short circuit between the metal substrate and the conductor layer. Can be within range.

The base insulating layer used in the present invention has a through hole in which the via is formed in the slider mounting region.
The size of such a through hole can be the same as that generally used for a suspension substrate.

  The method for forming the base insulating layer used in the present invention is not particularly limited as long as it can form a base insulating layer having a desired pattern. For forming a liquid base insulating layer containing the above-described material. A method can be used in which a coating liquid is applied or a dry film-like material is bonded, followed by patterning by exposure / development or photolithography.

4). Conductor Layer The conductor layer used in the present invention has at least connection wiring formed on the base insulating layer. In addition, a via wiring layer and a solder pad formed in the slider mounting region are included.

The solder pad used in the present invention is connected to the connection wiring or the via wiring and is connected to the slider via solder, and is surrounded by the dry film resist layer in a plan view to expose the surface. Is.
In addition, the case where the surface is exposed includes the case where it is covered with a plating layer described later.

The shape of the solder pad used in the present invention in plan view is not particularly limited as long as it can be stably connected to the slider, and as shown in FIG. The shape can be the same as the shape of a solder pad formed on a general suspension board.
The size of the solder pad is not particularly limited as long as it can be stably connected to the slider, and may be the same as the size of a solder pad formed on a general suspension board. it can.

  The distance between the solder pad adjacent to the solder pad in the present invention is not particularly limited as long as the distance between the two can be separated by the dry film resist layer, and specifically, a range of 40 μm to 200 μm. In particular, it is preferably in the range of 40 μm to 80 μm. It is because it is easy to arrange | position a dry film resist layer between the said solder pads by being in the said range. In addition, a sufficient number of solder pads can be formed in the slider mounting region.

The via wiring layer in the present invention has a through hole in which a via connected to the metal substrate is formed.
The size of such a through hole can be the same as that generally used for a suspension substrate.
Further, the formation position of the through hole in the via wiring layer is not particularly limited as long as it is within the slider mounting region, and is set according to the type of the suspension substrate of the present invention. .

The connection wiring in the present invention connects the slider mounting region and the external terminal portion.
Such a connection wiring pattern is not particularly limited as long as it can stably connect the slider mounting region and the external terminal portion.

  Examples of the material for the conductor layer used in the present invention include metals, and copper (Cu) is particularly preferable.

  The thickness of the conductor layer used in the present invention is not particularly limited as long as the conductor layer can be formed with high accuracy. For example, the thickness can be within a range of 5 μm to 18 μm. However, it is preferably in the range of 9 μm to 12 μm.

  The method for forming the conductor layer used in the present invention is not particularly limited as long as the method can form the conductor layer with high accuracy, and a method generally used for a suspension substrate should be used. Can do. For example, a method of forming the conductor layer by forming a conductor layer forming layer made of the material of the conductor layer by an electroplating method or the like and then patterning by etching using a resist can be given.

The conductor layer used in the present invention may be covered with a plating layer. In particular, like the solder pad, the portion where the surface is exposed is preferably covered with a plating layer. An example of the plating layer is a gold plating layer. Further, a nickel plating layer may be formed as a base for the gold plating layer. The thickness of the plating layer can be, for example, in the range of 0.1 μm to 4.0 μm.
In the present invention, examples of the method for forming the plating layer include an electrolytic plating method.

5. Vias The vias used in the present invention are formed in the slider mounting region, are made of a conductive material filled in through holes formed in the base insulating layer and the via wiring layer, and the metal The substrate and the via wiring layer are connected.

  As such a conductive material, a metal (Ni, Cu, etc.) that can be connected by a metal material such as solder and deposited by plating can be generally used.

  The via used in the present invention is not particularly limited as long as it is filled so as to connect the metal substrate and the via wiring layer. Usually, as shown in FIGS. 2 and 3 already described. In addition, it is formed so as to cover a part of the via wiring layer in plan view.

  The thickness of the via from the surface of the via wiring layer in the present invention is not particularly limited as long as it can be stably connected to the via wiring layer, but usually 3 μm to 30 μm. It is within the range, and in particular, it is preferably within the range of 5 μm to 15 μm. This is because the via wiring layer can be stably connected.

  As a method for forming a via used in the present invention, any method can be used as long as the conductive material can be filled into the through holes of the base insulating layer and the via wiring layer. Method is used. For example, a method using an electroplating method can be given.

6). Suspension Substrate The suspension substrate of the present invention has at least the dry film resist layer, metal substrate, base insulating layer, conductor layer, and via.
In the present invention, as shown in FIG. 3 already described, it is preferable to have a cover layer formed so as to cover the conductor layer. Usually, a conductor layer or the like whose surface is exposed is covered with a high-cost material such as the plating layer in order to prevent attenuation of an electric signal or deterioration of the conductor layer or the like. For this reason, it is because the formation area of a plating layer can be made small and cost reduction can be aimed at by covering the conductor layer of the area | region which is not covered with the said dry film resist layer with the said cover layer.
Moreover, as shown in FIG. 3 already described, it is preferable that solder is laminated on the solder pad. This is because the mounting of the slider can be facilitated.

(1) Cover layer The cover layer used for this invention is formed so that the said conductor layer may be covered.

  The material used for forming such a cover layer is not particularly limited as long as it has an insulating property, and specifically, the material described in the above section “3. Base insulating layer” can be used.

The formation location of the cover layer used in the present invention is not particularly limited as long as it is other than the exposed area of the conductor layer such as a solder pad to be connected to other terminals using solder or the like. Instead, as shown in FIG. 3 which has already been described, the dry film resist layer may be a portion covering the connection wiring which is a conductor layer not covered with the dry film resist layer. The conductor layer covered with 6, that is, the via wiring layer 3 b may also be covered.
In the present invention, the cover layer is preferably formed so as to cover at least the conductor layer not covered with the dry film resist layer. Normally, the exposed conductor layer that is not covered by the cover layer is covered with a plating layer such as gold plating as described above. However, it is expensive to cover with such gold plating. Become. However, by covering the conductor layer in the region not covered with the dry film resist layer with the cover layer, the area of the plating layer such as gold plating can be reduced, and the cost can be reduced. Because it can.
Moreover, in this invention, it is preferable that it is formed so that the conductor layer covered with the said dry film resist layer may also be covered especially. When the cover layer, the plating layer, and the dry film resist layer are formed in this order, the conductor layer in the region covered with the dry film resist layer is covered with the cover layer when forming the plating layer. Can do. For this reason, it is possible to prevent the plating layer from being formed on the conductor layer covered with the dry film resist layer without using other resists, and to reduce the area of the plating layer. is there. Note that, when the via wiring layer included in the conductor layer is covered, the cover layer is usually formed except for the region covered by the via in the via wiring layer.

  The thickness of the cover layer used in the present invention is not particularly limited as long as it can prevent the conductor layer from being deteriorated or short-circuited. For example, it is preferably in the range of 2 to 30 μm, and preferably in the range of 2 to 10 μm. It is more preferable that This is because the flexibility of the suspension substrate of the present invention is not impaired even when formed outside the slider mounting region. Moreover, it is because attenuation | damping of an electrical signal and deterioration of the said conductor layer can fully be suppressed.

  The method for forming the cover layer in the present invention is not particularly limited as long as it is a method capable of forming the cover layer in a desired region, but a liquid cover layer forming coating solution containing the above material It is preferable to use a method of coating the conductive layer so as to cover the conductor layer and then patterning by exposure / development or photolithography. This is because the cover layer having the above thickness can be formed stably.

(2) Solder The solder used in the present invention is laminated on the solder pad.
As such solder, what is generally used for a suspension substrate can be used.

The solder in the present invention only needs to be stacked on at least a solder pad included in the slider mounting region, and may be stacked on a connection pad in another region.
In addition, the solder in the present invention has a volume smaller than the space surrounding the solder pad, but normally it can stably contact the slider when the slider is mounted on the dry film resist layer. As described above, the layer is thicker than the dry film resist layer, that is, so that the solder is higher than the surface of the dry film resist layer on which the slider is mounted in a sectional view.

  As a method for laminating the solder in the present invention, any method can be used as long as it can be stably laminated on the solder pad, for example, by screen printing such as a method of arranging solder balls after forming the dry film resist layer. An arrangement method can be cited.

B. Next, a method for manufacturing a suspension substrate will be described.
The method for manufacturing a suspension substrate according to the present invention includes a metal substrate, a base insulating layer formed on the metal substrate, a slider mounting region formed on the base insulating layer, and on the opposite side of the slider mounting region. A conductor layer having at least a connection wiring for connecting an external terminal portion disposed at an end, and the slider mounting region is filled in a through hole formed in the base insulating layer, A via made of a conductive material for connecting the metal substrate and the via wiring is formed, and the conductor layer in the slider mounting region is connected to the connection wiring or the via wiring and connected to the slider via solder. In addition, a dry film layer is formed in the mounting region so as to be disposed on the conductor layer and to surround the solder pad. A dry film resist layer made of a strike is disposed, and the dry film resist layer has a film thickness thicker than the via and keeps a slider disposed on the dry film resist layer parallel to the metal substrate. A method of manufacturing a suspension substrate disposed at a position, comprising: a laminated substrate preparation step of preparing a laminated substrate having the metal substrate, a base insulating layer, a conductor layer and a via; and the dry film resist, the laminated substrate In addition, a dry film resist layer forming step of forming the dry film resist layer by exposing and developing the dry film resist after being pasted so as to cover the solder pad, the conductor layer, and the via is provided. Is.

A method for manufacturing the suspension substrate of the present invention will be described with reference to the drawings. FIG. 13 is a schematic process diagram showing an example of a method for manufacturing a suspension substrate according to the present invention. As illustrated in FIG. 12, a metal substrate forming layer 1x is prepared, and a base insulating layer forming layer 2x is formed on the surface of the metal substrate forming layer 1x, and a sputtering method is applied on the base insulating layer forming layer 2x. Then, a seed layer (not shown) is formed, and then a conductor layer forming layer 3x is formed on the seed layer by electroplating to form a laminate (FIG. 13A).
Thereafter, as shown in FIG. 13B, a resist is formed using a dry film resist (DFR), wet etching is performed, and the solder pad 3b and via wiring layer 3b are formed from the conductor layer forming layer 3x. Then, after the metal substrate 1 is simultaneously formed from the metal substrate forming layer 1x with the connection wiring 3c, the resist is peeled off.
Next, as illustrated in FIG. 13C, a liquid cover layer forming coating solution is applied so as to cover the conductor layer, that is, the solder pad 3a, the via wiring layer 3b, and the connection wiring 3c. Then, a cover layer forming layer is formed by drying, a resist is then formed using DFR, the cover layer forming layer exposed from the resist is wet etched, and a part of the via wiring layer 3b and the connection are formed. A cover layer 7 is formed so as to cover the wiring 3c.
Next, as illustrated in FIG. 13D, a resist is formed using DFR, the base insulating layer forming layer 2x exposed from the resist is wet-etched, and a through hole for forming a via is formed in the slider mounting region. The base insulating layer 2 is formed.
Thereafter, as illustrated in FIG. 13E, vias 5 are formed by electroplating to obtain a laminated substrate.
Next, as illustrated in FIG. 13F, the dry film resist 6a is formed on the slider mounting region 20 of the multilayer substrate in plan view, with the conductor layer, that is, the solder pad 3a, the via wiring 3b, and After being attached so as to cover the connection wiring 3c, the dry film resist 6a is exposed and developed through a photomask to form the dry film resist layer 6, thereby obtaining the suspension substrate 10 (FIG. 13G). )).
13A, 13B, 13D, and 13E are laminated substrate preparation steps, and FIGS. 13F to 13G are dry film resist layer forming steps.
Moreover, about the code | symbol in FIG. 13, since it shows the member same as the thing of FIGS. 2-3, description here is abbreviate | omitted.

  According to the present invention, by having the dry film resist layer forming step, a suspension substrate having excellent flatness can be easily obtained.

The method for manufacturing a suspension substrate according to the present invention includes at least the laminated substrate preparation step and the dry film resist layer formation step.
Hereafter, each process of the manufacturing method of the board | substrate for suspensions of this invention is demonstrated.
The suspension substrate obtained by the present invention is the same as the content described in the above “A. Suspension substrate”, and the description is omitted here.

1. Laminated substrate preparation step The laminated substrate preparation step in the present invention is a step of preparing a laminated substrate having the metal substrate, the base insulating layer, the conductor layer, and the via.

The formation method of each component of the laminated substrate in this step is the same as the content described in the above “A. Suspension substrate”, and therefore description thereof is omitted here.
The metal substrate, the base insulating layer, and the conductor layer may be formed by forming the base insulating layer and the conductor layer in this order on the metal substrate, and constitute the metal substrate. A metal substrate forming layer made of a material, a base insulating layer forming layer formed on the metal substrate forming layer and made of a material capable of forming the base insulating layer, and formed on the base insulating layer forming layer Then, after forming a laminated body having a conductor layer forming layer made of a material capable of forming the conductor layer, the conductor layer, the metal substrate, and the base insulating layer may be formed in this order.
In the present invention, the method using the laminate is particularly preferable. It is because each said structure can be formed with sufficient precision.

2. Dry film resist layer forming step In the dry film resist layer forming step of the present invention, the dry film resist is attached to the laminated substrate so as to cover the conductor layer and the via, and then the dry film resist is exposed and developed. And a step of forming the dry film resist layer.

  In this step, the dry film resist may be attached to the laminated substrate as long as the conductive layer on the laminated substrate is covered and the dry film resist has a flat surface. For example, a method of attaching by thermocompression bonding can be used.

  In this step, the dry film resist may be attached to the base insulating layer so as to cover at least the position where the dry film resist layer is formed. It may be a thing.

  In this step, the conditions for the thermocompression bonding are not particularly limited as long as the surface of the dry film resist is flat and can be sufficiently adhered to the insulating base layer. It is appropriately set according to the type and the like.

  In this step, a general dry film resist patterning method can be used as a method for exposing and developing the dry film resist.

  The dry film resist can be the same as the contents described in the section “1. Dry film resist layer” of the “A. Suspension substrate”, and the description thereof is omitted here.

3. Suspension Substrate The manufacturing method of a suspension substrate in the present invention includes at least the laminated substrate preparation step and the dry film resist layer formation step, but may include other steps as necessary.
Examples of such other processes include a cover layer forming process for forming a cover layer so as to cover the conductor layer, and a plating layer forming for forming a plating layer on the surface of the solder pad or the exposed conductor layer. It may have a process, a solder lamination process of laminating solder on the solder pad, and the like.
In the cover layer forming step, the method of forming the cover layer and the cover layer to be formed are described in “(1) Cover layer” of “6. Suspension substrate” of “A. Suspension substrate”. The contents are the same as described in the section. In the plating layer forming step, the method for forming the plating layer and the plating layer to be formed are the same as those described in the section “4. Conductor layer” of “A. Suspension substrate”. Therefore, explanation here is omitted.
Moreover, as a method of laminating the solder in the solder laminating step or the like, a method of arranging a solder ball on the solder pad can be exemplified.

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

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

  FIG. 14 is a schematic plan view showing an example of the suspension of the present invention. A suspension 30 shown in FIG. 14 has the above-described suspension substrate 10 and a load beam 31 provided on the surface of the suspension substrate 10 opposite to the surface on which the slider mounting region 20 is formed. is there.

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

D. Next, the suspension with an element of the present invention will be described. The suspension with an element of the present invention includes the above-described suspension and an element (slider) mounted in a slider mounting region of the suspension.

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

  FIG. 15 is a schematic plan view showing an example of the suspension with an element of the present invention. A suspension with an element 40 shown in FIG. 15 includes the suspension 30 described above and an element (slider) 41 mounted on the slider mounting area 20 of the suspension 30.

  The suspension with an element of the present invention has at least a suspension and an element (slider). The suspension described above is the same as that described in “C. Suspension”, and is not described here. The slider is the same as the slider described in the section “A. Suspension substrate”, and the description thereof is omitted here.

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

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

  FIG. 16 is a schematic plan view showing an example of the hard disk drive of the present invention. A hard disk drive 50 shown in FIG. 16 includes the above-described suspension 40 with an element, a disk 51 on which data is written and read by the suspension 40 with an element, a spindle motor 52 that rotates the disk 51, and the elements of the suspension 40 with an element. And a voice coil motor 54, and a case 55 for sealing the above-described members.

  The hard disk drive of the present invention has at least a suspension with an element, and usually further includes a disk, a spindle motor, an arm, and a voice coil motor. 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.

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

  Hereinafter, the present invention will be specifically described using examples and comparative examples.

[Example 1]

  A base insulating layer forming layer having a thickness of 10 μm was formed by a coating method on the metal supporting substrate forming layer of SUS304 having a thickness of 20 μm, using the first non-photosensitive polyimide as an insulating layer forming material. . Further, a Ni—Cr—Cu layer serving as a seed layer is coated on the base insulating layer forming layer by a sputtering method to a thickness of about 300 nm, and this is used as a conductive medium to form a conductor layer which is a 9 μm thick Cu plating layer by Cu plating. A forming layer was formed to obtain a three-layer laminate including a metal support substrate forming layer, a base insulating layer forming layer, and a conductor layer forming layer.

  A dry film so that a jig layer in which positional accuracy is important on the SUS (metal support substrate forming layer) side and a conductor layer including the desired connection wiring on the Cu plating layer (conductor layer forming layer) side can be formed. Were simultaneously patterned to obtain a patterned resist. Thereafter, etching is performed using a ferric chloride solution, resist stripping is performed after etching, jig holes are formed in the metal support substrate forming layer, and the connection wiring and terminal portions are formed on the base insulating layer forming layer. A conductor layer including a (solder pad) and via wiring was formed.

  A non-photosensitive polyimide-based liquid cover layer forming material is coated with a die coater, dried, resist-engraved, and the cover layer forming material is etched at the same time as development, then cured, and then a cover layer forming material having a thickness of 3 to 5 μm. A cover layer made of (second non-photosensitive polyimide) was formed on the conductor layer and the insulating layer including the connection wiring and the like.

  Next, the base insulating layer forming layer (first non-photosensitive polyimide layer) is engraved with a resist, etched using an organic alkaline etchant, and stripped after the etching to obtain a patterned base insulating layer .

  Next, after the terminal portion (solder pad) was acid cleaned, electrolytic Au plating was performed to form a plated portion on the surface of the terminal portion. The thickness of the plating part was 1.5 to 2.5 μm.

  For the purpose of establishing conduction between the metal support substrate forming layer and the conductor layer, resist plate making was performed again, electrolytic Ni plating was performed, and the resist was peeled off to obtain a via. A standard sulfamic acid Ni plating bath was used as the electrolytic Ni plating bath, and electrolytic Ni plating was performed by electrolytic immersion plating (0.2 A, 14 minutes). The via thickness was 3 to 8 μm from the conductor layer.

  In order to perform the outer shape processing of SUS, resist engraving was performed again, and only the SUS side (metal support substrate forming layer) was etched. After etching, resist stripping was performed. In this way, a metal support substrate was formed.

About the wiring board which performed resist peeling, exposure and image development were performed so that it might become a dry film resist layer of a predetermined shape, using SS8000 thickness 38um by Toa Gosei Co., Ltd. as a dry film resist. Thereafter, heat treatment is performed to heat and cure the dry film resist, and the thickness from the conductor layer is 10 to 12 μm, and is formed so as to surround the terminal portion (solder pad), and is thicker than the via. A dry film resist layer was formed.
In this way, a suspension substrate was formed.

DESCRIPTION OF SYMBOLS 1 ... Metal substrate 2 ... Base insulating layer 3a ... Solder pad 3b ... Via wiring layer 3c ... Conductor layer 5 ... Via 6 ... Dry film resist layer 7 ... Cover layer 8 ... Plating layer 10 ... Suspension substrate 11 ... Solder 20 ... Slider mounting area 30 ... Suspension 31 ... Load beam 40 ... Suspension with element 41 ... Element (slider)
DESCRIPTION OF SYMBOLS 50 ... Hard disk drive 51 ... Disk 52 ... Spindle motor 53 ... Arm 54 ... Voice coil motor 55 ... Case

Claims (9)

A metal substrate;
A base insulating layer formed on the metal substrate;
A conductor layer that is formed on the base insulating layer and has at least a connection wiring that connects a slider mounting region and an external terminal portion disposed at an end opposite to the slider mounting region;
The said slider mounting region a suspension substrate with the insulating base layer and becomes filled in the through hole formed in the via wiring, wherein the metal substrate and the conductive material for connecting the via wiring A via consisting of
The conductor layer in the slider mounting region is connected to the connection wiring or the via wiring, and a solder pad for connecting to the slider via solder is formed,
Further, in the slider mounting region, a dry film resist layer made of a dry film resist disposed on the conductor layer and formed so as to surround the solder pad is disposed,
The dry film resist layer has a thickness that is thicker than the via, and is disposed at a position that keeps the slider disposed on the dry film resist layer parallel to the metal substrate,
Further, the dry film resist layer has a through hole that exposes the surface of the solder pad, and the solder pad surface in the through hole is from a surface of the dry film resist layer opposite to the metal substrate. A suspension substrate, which is located on the metal substrate side and has a recess.   The suspension substrate according to claim 1, wherein the dry film resist is made of a photosensitive polyimide resin.   The suspension substrate according to claim 1, further comprising a cover layer formed so as to cover the conductor layer.   The suspension substrate according to any one of claims 1 to 3, wherein the dry film resist layer is formed so as to cover the via.   The suspension substrate according to any one of claims 1 to 4, wherein solder is laminated on the solder pad.   A suspension comprising the suspension substrate according to any one of claims 1 to 5.   A suspension with an element, comprising: the suspension according to claim 6; and an element mounted on a slider mounting region of the suspension.   A hard disk drive comprising the suspension with an element according to claim 7. A metal substrate;
A base insulating layer formed on the metal substrate;
A conductor layer that is formed on the base insulating layer and has at least a connection wiring that connects a slider mounting region and an external terminal portion disposed at an end opposite to the slider mounting region;
Have
Wherein the slider mounting region, the filled in the base insulating layer and through-holes formed in the via wiring becomes in a via made of a conductive material for connecting wiring the metal substrate and the vias are formed,
The conductor layer in the slider mounting region is connected to the connection wiring or the via wiring, and a solder pad for connecting to the slider via solder is formed,
Further, in the slider mounting region, a dry film resist layer made of a dry film resist disposed on the conductor layer and formed so as to surround the solder pad is disposed,
The dry film resist layer has a thickness that is thicker than the via, and is disposed at a position that keeps the slider disposed on the dry film resist layer parallel to the metal substrate,
Further, the dry film resist layer has a through hole that exposes the surface of the solder pad, and the solder pad surface in the through hole is from a surface of the dry film resist layer opposite to the metal substrate. A suspension substrate manufacturing method for manufacturing a suspension substrate located on the metal substrate side and forming a recess,
A laminated substrate preparing step of preparing a laminated substrate having the metal substrate, base insulating layer, conductor layer and via;
A dry film resist layer for forming the dry film resist layer by applying the dry film resist to the laminated substrate so as to cover the solder pads, conductor layers and vias, and then exposing and developing the dry film resist. A method for manufacturing a suspension substrate, comprising a forming step.

Images