JP2014191844A - Substrate for suspension, suspension, suspension having element, and hard disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate for suspension capable of reducing differential impedance while suppressing increase of a wiring area and maintaining a wide bandwidth of a high frequency signal, and in addition, suppressing transmission loss.SOLUTION: In a substrate for suspension, wiring ais electrically connected to wiring cby a via part V, wiring ais electrically connected to wiring cby a via part V, the wiring cand the wiring care electrically connected by jumper wiring J, and wiring bis electrically connected to wiring dby a via part Vformed on an opposite side to a connection terminal Tin planar view, with jumper wiring Jas a border.

Description

  The present invention is mainly used in a hard disk drive (HDD), and is used for a suspension in which a recording / reproducing element (for example, a magnetic head slider) for writing and reading data on a disk on which data is stored is mounted. It relates to a substrate.

  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.

Generally, a hard disk drive (HDD) includes a suspension substrate on which a recording / reproducing element (for example, a magnetic head slider) for writing and reading data to and from a disk storing data is mounted.
The suspension substrate generally includes a metal support substrate having spring properties, an insulating layer formed on the metal support substrate, and a wiring formed on the insulating layer.

  Here, in some of the above-mentioned wirings (for example, write wiring and read wiring), electrical signals are transmitted by differential transmission, and differential transmission as a distributed constant circuit is performed between a pair of wirings. There is a differential impedance that is the characteristic impedance of the road. This differential impedance is required to be reduced from the viewpoint of impedance matching as the recording / reproducing element (for example, magnetic head slider) and preamplifier are reduced in impedance.

  As a wiring structure capable of reducing this differential impedance, a pair of wiring composed of a wiring for transmitting a first electrical signal and a wiring for transmitting a second electrical signal having a phase opposite to that of the first electrical signal. The differential wiring is branched into two or more wirings, and the wiring for transmitting the first electrical signal and the wiring for transmitting the second electrical signal having the opposite phase to the first electrical signal are respectively planar. A wiring structure (interleaved wiring structure) that is alternately arranged has been proposed (for example, Patent Document 1).

  As a method of forming the interleaved wiring structure as described above on the suspension substrate, for example, as shown in FIG. 21A, the first insulating layer 112 formed on the metal supporting substrate 111A is mutually bonded. The plurality of first signal wirings (eg, 113a and 113c) that are electrically connected and the first signal wiring are electrically independent, and the plurality of second signal wirings (eg, 113b and 113d) that are electrically connected to each other. ), And the second insulating layer 114 is formed on these wirings (113a, 113b, 113c, 113d) (for example, Patent Document 2). The first signal wiring and the second signal wiring constitute a pair of differential wirings, and an electric signal (first electric signal) transmitted to the first signal wiring and an electric signal (first electric signal) transmitted to the second signal wiring ( The second electrical signal) has a phase relationship opposite to each other.

  However, in the configuration shown in FIG. 21A, the wirings 113a, 113b, 113c, and 113d and the underlying metal support substrate 111A form inductive or capacitive coupling, and thus the wirings 113a, 113b, and 113c are formed. , 113d, an electric signal (especially a high-frequency signal) is transmitted to the metal support substrate 111A with low conductivity, and a transmission loss increases. Therefore, as shown in FIG. 21 (b), the metal support substrate in the portion overlapping with the wirings 113a, 113b, 113c, and 113d in a plan view is removed to provide an opening 117 to reduce the inductive or capacitive coupling. A method has also been proposed (for example, Patent Document 3).

FIG. 22 is an explanatory diagram showing a circuit configuration of the interleave wiring of the suspension board shown in FIG. 21 (a) or (b).
As shown in FIG. 22, the interleaved wiring structure 130 includes a first signal wiring that electrically connects the connection terminal 131a and the connection terminal 131c, and a second signal that electrically connects the connection terminal 131b and the connection terminal 131d. The first signal wiring is branched into a wiring 113a and a wiring 113c at a branch point 132a, and similarly, the second signal wiring is connected to a wiring 113b at a branch point 132b. Branching to the wiring 113d, the branched wirings are arranged in parallel in the order of 113a, 113b, 113c, 113d from the left end of the drawing so that the wiring for transmitting electrical signals having opposite phases to each other is adjacent. .
The wirings 113a and 113c through which electrical signals having the same phase are transmitted are electrically connected by connection lines 134a via via portions 133a and 133b provided in the second insulating layer 114, respectively. In addition, the wirings 113b and 113d are electrically connected by the connection line 134b via the via portions 133c and 133d.

JP-A-10-124837 JP 2010-114366 A JP 2011-76645 A

In order to cope with further reduction in impedance in the suspension substrate having the above-described configuration, for example, a method of increasing the number of wirings constituting the interleaved wiring structure or a thickness of the wiring constituting the interleaved wiring structure is increased. The method of doing is mentioned.
However, the method of increasing the number of wirings in a plane is not preferable because the area occupied by the wiring group becomes large. For example, if the area occupied by the wiring group becomes large, the opening of the metal support substrate provided under the wiring group in order to suppress the above-described transmission loss also becomes large, which causes a problem in terms of physical strength.
On the other hand, the method of increasing the thickness of the wiring has a problem that manufacturing difficulty increases because the thickness of the wiring increases with respect to the space width between the wirings and processing with a high aspect ratio is required.

Here, in the interleaved wiring structure described above, for example, as shown in FIG. 21A or FIG. 21B, the capacitive coupling between the wirings is formed by making the side surfaces of the wirings in opposite phases face each other. doing. Therefore, for reducing the impedance, for example, it is effective to increase the thickness of the wiring as described above, that is, to increase the area of the facing surface of the wiring.
Therefore, for example, as shown in FIG. 23, wirings 213a and 213b having opposite phases to each other are stacked via the second insulating layer 214, and upper and lower surfaces of each wiring (the bottom surface of the upper wiring and the upper surface of the lower wiring). ) To form a capacitive coupling to reduce the differential impedance.

With such a method, it is possible to increase the area of the facing surface (that is, to increase the wiring width) or to reduce the distance between the facing surfaces, compared to the case where capacitive coupling is formed on the side surface of the wiring. It is technically easy to do (that is, to reduce the thickness of the insulating layer between the wirings).
However, in the configuration in which wirings for transmitting electrical signals having opposite phases to each other as described above are laminated via an insulating layer, the insulating layer between the wirings is formed as a thin film in order to reduce the overall thickness of the suspension substrate. Then, it has been found that there is a problem that high-frequency characteristics deteriorate due to the interaction between upper and lower anti-phase wirings (more specifically, a problem that the bandwidth of transmission characteristics becomes narrower).

  The present inventor has formed the first wiring group constituting the interleaved wiring structure on the first insulating layer formed on the metal support substrate in the research so far, A second wiring group constituting an interleaved wiring structure is stacked on the first wiring group via a second insulating layer, and an electric signal of the same phase is placed on each wiring of the first wiring group. It has been found that the above problem can be solved by arranging each wiring of the second wiring group to be transmitted.

  On the other hand, when this configuration is adopted, a new problem arises. Here, each wiring which comprises an interleave wiring structure needs to be electrically connected mutually. Therefore, in the first wiring group, the wirings constituting the interleaved wiring structure need to be electrically connected to each other, and in the second wiring group, the wirings constituting the interleaved wiring structure are mutually connected. Must be electrically connected. Furthermore, since each wiring of the second wiring group that transmits the same phase electric signal is arranged on each wiring of the first wiring group, the same wiring is used in the first wiring group and the second wiring group. Wirings through which phase electrical signals are transmitted must also be electrically connected. Thus, when adopting the above-described configuration, there is a problem that the wiring connection method is rapidly advanced.

  Here, in order to electrically connect each wiring which comprises an interleave wiring structure, it is possible to use a part of metal supporting board as a jumper wiring. Specifically, as shown in FIG. 24, the wiring 113b and the wiring 113d constituting the interleaved wiring structure are formed using the jumper wiring 111a of the metal supporting board and the via portion 5 penetrating the first insulating layer 112. An electrical connection method can be considered. However, the metal support substrate usually has a problem that the transmission loss is large because the conductivity is lower than that of the wiring.

  The present invention has been made in view of the above circumstances, and can suppress the increase of the wiring area, reduce the differential impedance while maintaining a wide bandwidth of the high-frequency signal, and further transmit the signal. The main object is to provide a suspension substrate capable of suppressing loss.

In order to solve the above problems, in the present invention, a metal support substrate, a first insulating layer formed on the metal support substrate, and a first insulating layer formed on the first insulating layer. A wiring group; a second insulating layer formed on the first wiring group and the first insulating layer; and a second wiring group formed on the second insulating layer. The first wiring group includes a signal wiring A having a plurality of wirings electrically connected to each other, and the signal wiring A is electrically independent and electrically connected to each other. Signal wiring B having a plurality of wirings arranged alternately in a plane, and the second wiring group includes a signal wiring C having a plurality of wirings electrically connected to each other and the signal wiring B A signal distribution having a plurality of wirings electrically independent from the wiring C and electrically connected to each other. D and the signal wiring A and the signal wiring C are opposed to each other through the second insulating layer, and the signal wiring B and the signal wiring D are the first wiring. The first wiring group and the second wiring group are arranged so as to face each other via two insulating layers, and the signal wirings A to D are respectively connected to the wirings a _{1 to} d ₁ and the wirings a ₂ to d ₂ , and the wiring a ₁ is electrically connected to the connection terminal T _α1, and is further formed by a via portion V _ac11 formed on the wiring a ₁ and penetrating the second insulating layer. The wiring a ₁ is electrically connected to the wiring c _1, and the wiring a ₂ is electrically connected to the wiring c ₂ by the via portion V _ac21 formed on the wiring a ₂ and penetrating the second insulating layer. are connected, the wiring c ₁ and the wiring c ₂ are belong to the signal line C Electrically connected by jumper wires J _C12 that, the wiring b _1, a connection terminal T _.beta.1 and is electrically connected, further, are formed on the wiring b _1, as a boundary the jumper wiring J _c12, plane The suspension is formed on the side opposite to the connection terminal T _β1 and is electrically connected to the wiring d ₁ by a via portion V _bd11 that penetrates the second insulating layer. A substrate is provided.

  According to the present invention, by arranging the wiring and the via portion at a specific position, a desired wiring structure can be obtained without using the jumper wiring of the metal supporting board. Thereby, it can be set as the board | substrate for suspensions which suppressed the transmission loss. Further, according to the present invention, the signal wiring A and the signal wiring C are opposed to each other through the second insulating layer, and the signal wiring B and the signal wiring D are opposed to each other through the second insulating layer. By disposing the first wiring group and the second wiring group, it is possible to reduce the differential impedance while keeping the bandwidth of the high-frequency signal wide while suppressing an increase in the wiring area.

In the above invention, the wiring b ₂ is electrically connected to the connection terminal T _β2, and is further formed on the wiring b ₂ and through the second insulating layer by the via portion V _bd22 . wire d ₂ and is electrically connected to the wiring b ₁ is formed on the wiring b _1, and by the via V _BD12 penetrating the second insulating layer, the wiring d ₁ and electrically The wiring d ₁ and the wiring d ₂ are electrically connected by a jumper wiring J _d12 belonging to the signal wiring D, the wiring a ₂ is electrically connected to the connection terminal T _α2, and A via portion V _ac22 formed on the wiring a ₂ and formed on the side opposite to the connection terminal T _α2 in plan view with the jumper wiring J _d12 as a boundary, and penetrates the second insulating layer. ,Up It is preferable that the wiring c ₂ and are electrically connected.

In the present invention, a metal support substrate, a first insulating layer formed on the metal support substrate, a first wiring group formed on the first insulating layer, and the first A suspension substrate having one wiring group and a second insulating layer formed on the first insulating layer, and a second wiring group formed on the second insulating layer. The first wiring group includes a signal wiring A having a plurality of wirings electrically connected to each other and a plurality of wirings electrically connected to each other and electrically connected to the signal wiring A. The second wiring group includes signal wirings C having a plurality of wirings electrically connected to each other, and the signal wirings C are electrically connected to each other. And signal wiring D having a plurality of wirings electrically connected to each other in a plane. The signal wiring A and the signal wiring C are opposed to each other through the second insulating layer, and the signal wiring B and the signal wiring D are opposed to each other through the second insulating layer. As described above, the first wiring group and the second wiring group are arranged, and the signal wirings A to D have wirings a _{1 to} d ₁ and wirings a _{2 to} d ₂ , respectively. c _1, a connection terminal T _{[alpha] 1} and is electrically connected, further, are formed on the wiring a _1, and by the via V _AC11 penetrating the second insulating layer, the wiring a ₁ electrically is connected to, the wiring c ₂ is formed on the wiring a _2, and, by the via V _AC21 penetrating the second insulating layer, is the wiring a ₂ and electrically connected, the wiring a ₁ and the wiring a ₂ are jumper wirings J belonging to the signal wiring A _a12 by being electrically connected, the wiring d _1, a connection terminal T _.beta.1 and is electrically connected, further, are formed on the wiring b _1, as a boundary the jumper wiring J _a12, the connection in a plan view Provided is a suspension substrate characterized in that it is formed on the side opposite to the terminal T _β1 and is electrically connected to the wiring b ₁ by a via portion V _bd11 penetrating the second insulating layer. To do.

  According to the present invention, by arranging the wiring and the via portion at a specific position, a desired wiring structure can be obtained without using the jumper wiring of the metal supporting board. Thereby, it can be set as the board | substrate for suspensions which suppressed the transmission loss. Further, according to the present invention, the signal wiring A and the signal wiring C are opposed to each other through the second insulating layer, and the signal wiring B and the signal wiring D are opposed to each other through the second insulating layer. By disposing the first wiring group and the second wiring group, it is possible to reduce the differential impedance while keeping the bandwidth of the high-frequency signal wide while suppressing an increase in the wiring area.

In the above invention, the wiring d ₂ is electrically connected to the connection terminal T _β2, and is further formed on the wiring b ₂ and through the second insulating layer by the via portion V _bd22 . wire b ₂ and is electrically connected to the wiring d ₁ is formed on the wiring b _1, and by the via V _BD12 penetrating the second insulating layer, the wiring b ₁ and electrically The wiring b ₁ and the wiring b ₂ are electrically connected by a jumper wiring J _b12 belonging to the signal wiring B, the wiring c ₂ is electrically connected to a connection terminal T _α2, and is formed on the wiring a _2, a boundary the jumper wiring J _b12, and the connection terminals T _{[alpha] 2} in a plan view are formed on the opposite side, and by the via V _{AC 22} penetrating the second insulating layer ,Up It is preferable that the wiring a ₂ and are electrically connected.

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

  According to the present invention, by using the above-described suspension substrate, a suspension in which transmission loss is suppressed can be obtained.

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

  According to the present invention, by using the above-described suspension, it is possible to provide a suspension with an element in which transmission loss is suppressed.

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

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

  The suspension substrate of the present invention has the effect that the differential impedance can be reduced and the transmission loss can be further suppressed while keeping the bandwidth of the high-frequency signal wide while suppressing the increase of the wiring area. Play.

It is a schematic plan view which shows an example of the board | substrate for suspensions of a 1st embodiment. It is AA sectional drawing of FIG. It is a schematic perspective view which shows an example of a 1st wiring group and a 2nd wiring group. It is a schematic perspective view which shows an example of arrangement | positioning of the wiring and via | veer part in a 1st embodiment. It is a schematic perspective view which shows the other example of arrangement | positioning of the wiring and via | veer part in a 1st embodiment. It is a schematic perspective view which shows the other example of arrangement | positioning of the wiring and via | veer part in a 1st embodiment. It is a schematic perspective view which shows the other example of arrangement | positioning of the wiring and via | veer part in a 1st embodiment. It is a schematic perspective view which shows the other example of arrangement | positioning of the wiring and via | veer part in a 1st embodiment. It is a schematic sectional drawing which shows an example of the manufacturing method of the board | substrate for suspensions of a 1st embodiment. It is a schematic perspective view which shows an example of arrangement | positioning of the wiring and via | veer part in a 2nd embodiment. It is a schematic perspective view which shows the other example of arrangement | positioning of the wiring and via | veer part in a 2nd embodiment. It is a schematic perspective view which shows the other example of arrangement | positioning of the wiring and via | veer part in a 2nd embodiment. It is a schematic perspective view which shows the other example of arrangement | positioning of the wiring and via | veer part in a 2nd embodiment. 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. 3 is a schematic cross-sectional view illustrating a suspension substrate in Example 1. FIG. 6 is a schematic cross-sectional view illustrating a suspension substrate in Comparative Example 1. FIG. 5 is a schematic cross-sectional view illustrating a suspension substrate in Example 2. FIG. 10 is a schematic cross-sectional view illustrating a suspension substrate in Comparative Example 2. FIG. It is a schematic sectional drawing which shows the structural example of the conventional board | substrate for suspensions. It is explanatory drawing which shows the circuit structure of the interleave wiring of the board | substrate for suspensions shown in FIG. It is a schematic sectional drawing which shows the structural example which laminated | stacked a pair of differential wiring. It is a schematic sectional drawing explaining the jumper wiring of a metal support substrate.

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

A. Suspension substrate The suspension substrate of the present invention can be roughly divided into two embodiments. Hereinafter, the suspension substrate of the present invention will be described separately for the first embodiment and the second embodiment.

1. First Embodiment A suspension substrate according to a first embodiment includes a metal supporting substrate, a first insulating layer formed on the metal supporting substrate, and a first insulating layer formed on the first insulating layer. A wiring group, a second wiring layer formed on the first wiring group and the first insulating layer, a second wiring group formed on the second insulating layer, The first wiring group includes a signal wiring A having a plurality of wirings electrically connected to each other, and the signal wiring A is electrically independent and electrically connected to each other. The signal wirings B having a plurality of connected wirings are alternately arranged in a plane, and the second wiring group includes the signal wirings C having a plurality of wirings electrically connected to each other, The signal wiring C is electrically independent and has a plurality of wirings electrically connected to each other. The signal wirings D are alternately arranged in a plane, the signal wiring A and the signal wiring C are opposed to each other through the second insulating layer, and the signal wiring B and the signal wiring D are The first wiring group and the second wiring group are arranged so as to face each other through the second insulating layer, and the signal wirings A to D are respectively connected to the wirings a _{1 to} d ₁ and the wiring a. _{2 to} d ₂ , and the wiring a ₁ is electrically connected to the connection terminal T _α1, and is further formed on the wiring a ₁ and further penetrates the second insulating layer. the _AC11, the wiring _{c 1} and is electrically connected to the wiring _{a 2} is formed on the wiring _{a 2,} and, by the via _{V AC21} penetrating the second insulating layer, the wiring _{c 2} The wiring c ₁ and the wiring c ₂ are electrically connected to the signal wiring. Electrically connected by a jumper wiring J _C12 belonging to C, and the wiring b ₁ is electrically connected to a connection terminal T _β1 and further formed on the wiring b _{1 with the} jumper wiring J _c12 as a boundary. In the plan view, it is formed on the side opposite to the connection terminal T _β1 and is electrically connected to the wiring d ₁ by a via portion V _bd11 penetrating the second insulating layer. To do.

  FIG. 1 is a schematic plan view showing an example of a suspension substrate according to the first embodiment. As shown in FIG. 1, the suspension substrate 100 of the first embodiment has a recording / reproducing element mounting region 101 for mounting a recording / reproducing element (for example, a magnetic head slider) at the head side end. An external circuit board connection region 102 for connecting to an external reading circuit or writing circuit is provided at the tail side end. Also, the suspension substrate 100 of the first embodiment includes a wiring group 103a including a write wiring and a wiring group 103b including a read wiring between the recording / reproducing element mounting region 101 and the external circuit board connection region 102. Have.

  FIG. 2 is a cross-sectional view taken along the line AA of FIG. As shown in FIG. 2, the suspension substrate 100 includes a metal supporting substrate 1, a first insulating layer 2x formed on the metal supporting substrate 1, and a first insulating layer 2x formed on the first insulating layer 2x. A first wiring group 3x, a second wiring layer 2y formed on the first wiring group 3x and the first insulating layer 2x, and a second wiring formed on the second insulating layer 2y. A group 3y and a cover layer 4 formed to cover the second wiring group 3y.

FIG. 3 is a schematic perspective view showing an example of the first wiring group and the second wiring group. As shown in FIG. 3, the first wiring group 3x includes a signal wiring A having a plurality of wirings a ₁ and a ₂ that are electrically connected to each other, and the signal wiring A is electrically independent and electrically connected to each other. Signal wiring B having a plurality of interconnected wirings b ₁ and b ₂ are arranged alternately in a plane. Similarly, in the second wiring group 3y, the signal wiring C having a plurality of wirings c ₁ and c ₂ electrically connected to each other and the signal wiring C are electrically independent and electrically connected to each other. The signal wirings D having a plurality of wirings d ₁ and d ₂ are alternately arranged in a plane. Further, the signal wiring A and the signal wiring C are opposed to each other via a second insulating layer (not shown), and the signal wiring B and the signal wiring D are also opposed to each other via a second insulating layer (not shown). As described above, the first wiring group 3x and the second wiring group 3y are arranged.

  In FIG. 3, an ideal arrangement is shown for convenience in order to describe the positional relationship between the first wiring group and the second wiring group, but actually, the first wiring group and the second wiring group are shown. These wiring groups do not completely match in plan. In order to suppress transmission loss due to jumper wiring on the metal support substrate, it is necessary to devise the positions of the wiring and via portions.

FIG. 4 is a schematic perspective view showing an example of the arrangement of wirings and via portions in the first embodiment. In FIG. 4, the wiring indicated by the bold line indicates the wiring of the second wiring group, and the wiring indicated by the thin line indicates the wiring of the first wiring group (the same applies to other schematic perspective views). . In FIG. 4, signal wiring A has wiring a ₁ and wiring a ₂ , signal wiring B has wiring b ₁ and wiring b ₂ , signal wiring C has wiring c ₁ and wiring c ₂ , The wiring D includes a wiring d ₁ and a wiring d ₂ . Wire a ₁ is electrically connected to the connecting terminal T _{[alpha] 1.} Further, wiring _{a 1} is formed on the wiring _{a 1,} and by the via _{V AC11} penetrating the second insulating layer, and is electrically connected to the wiring _{c 1.} Wire _{a 2} is formed on the wiring _{a 2,} and, by the via _{V AC21} penetrating the second insulating layer, and is electrically connected to the wiring _{c 2.} The wiring c ₁ and the wiring c ₂ are electrically connected by a jumper wiring J _C12 belonging to the signal wiring C. Wire b _1, a connection terminal T _.beta.1 and are electrically connected. Furthermore, the wiring b ₁ is formed on the wiring b ₁ , is formed on the side opposite to the connection terminal T _β1 (in the center side of the suspension substrate) in plan view with the jumper wiring J _c12 as a boundary, and the second of the via portion V _{BD 11} passing through the insulating layer and is electrically connected to the wiring d _1. Wire _{b 2} is formed on the wiring _{b 2,} and by the via _{V BD21} penetrating the second insulating layer, and is electrically connected to the wiring _{d 2.}

  According to the first embodiment, by arranging the wiring and the via portion at a specific position, a desired wiring structure can be obtained without using the jumper wiring of the metal supporting board. Thereby, it can be set as the board | substrate for suspensions which suppressed the transmission loss. Further, by not using the jumper wiring of the metal support substrate, it is possible to suppress a decrease in the degree of freedom in designing the HDD. Here, from the viewpoint of ensuring flatness when mounting to the load beam and from the viewpoint of reducing the thickness of the suspension board, the jumper wiring of the metal support board is not provided with a short circuit measure such as providing a cover layer. There are many. For this reason, when the suspension substrate having the jumper wiring of the metal support substrate is attached to the load beam, a countermeasure against a short circuit is required separately, which may reduce the degree of freedom in designing the HDD. On the other hand, in the first embodiment, since a desired wiring structure can be obtained without using the jumper wiring of the metal support substrate, it is possible to suppress a decrease in the degree of freedom in designing the HDD. Note that the suspension substrate of the first embodiment is not limited as long as wiring and via portions are arranged at specific positions, and includes, for example, a suspension substrate having a jumper wiring of a metal support substrate in another part.

  Further, according to the first embodiment, the signal wiring A and the signal wiring C are opposed to each other through the second insulating layer, and the signal wiring B and the signal wiring D are opposed to each other through the second insulating layer. In addition, by arranging the first wiring group and the second wiring group, it is possible to reduce the differential impedance while keeping the bandwidth of the high-frequency signal wide while suppressing an increase in the wiring area. it can.

  Here, the point which can suppress that a wiring area | region increases is demonstrated. In the first embodiment, since the second wiring group is stacked on the first wiring group, the area occupied by both wiring groups in a plan view is the case where only the first wiring group is formed. Is the same. That is, by forming the second wiring group, the number of wirings constituting the interleaved wiring structure is doubled, but the area occupied by the wiring group is not increased, and only the first wiring group is formed. Can be the same as it is. When the openings of the metal supporting board are provided under both wiring groups, the size of the opening can be made the same as when only the first wiring group is formed. Physical strength can be maintained.

  Next, a description will be given of the fact that a wide bandwidth of the high-frequency signal can be maintained. As described above, the arrangement relationship between each wiring of the first wiring group and each wiring of the second wiring group is such that wirings that transmit the same phase electrical signals are opposed to each other through the second insulating layer. It is supposed to be. Therefore, even if the second insulating layer between the two wiring groups is made a thin film in order to reduce the overall thickness of the suspension substrate, the high frequency characteristics deteriorate due to the interaction between the upper and lower wirings ( More specifically, the problem that the bandwidth of the transmission characteristic becomes narrow does not occur.

Next, the point that the differential impedance can be reduced will be described. In the first embodiment, by forming the second wiring group, the number of wirings constituting the interleaved wiring structure is doubled compared to the case where only the first wiring group is formed (the total number of wirings is 8). Therefore, in the first embodiment, the differential impedance can be reduced to the same extent as in the case where two first wiring groups are arranged in a plane (total number of wirings is 8).
Hereinafter, the suspension substrate of the first embodiment will be described separately for the suspension substrate member and the configuration of the suspension substrate.

(1) Suspension substrate member The material of the metal support substrate is not particularly limited as long as it functions as a support for the suspension substrate and has a desired spring property. For example, stainless steel is used. Can be mentioned. For example, the thickness of the metal supporting substrate is preferably in the range of 10 μm to 30 μm, and more preferably in the range of 15 μm to 25 μm.

  The first insulating layer is formed on the surface of the metal supporting board, and electrically insulates each wiring of the first wiring group formed on the first insulating layer from the metal supporting board. To do. The material for the first insulating layer is not particularly limited as long as it has a desired insulating property and dielectric constant, and examples thereof include polyimide. The material of the first insulating layer may be a photosensitive material or a non-photosensitive material. The thickness of the first insulating layer is, for example, in the range of 5 μm to 30 μm.

  The wiring material is not particularly limited as long as it has desired conductivity, and examples thereof include copper (Cu). When each wiring is exposed, a protective plating layer of nickel (Ni) or gold (Au) may be formed on the surface thereof.

  For example, the thickness of the wiring is preferably in the range of 3 μm to 18 μm, and more preferably in the range of 4 μm to 15 μm. This is because if the wiring thickness is too small, it may not be possible to achieve a sufficiently low impedance, and if the wiring thickness is too large, the suspension substrate may become too rigid.

  The line width of the wiring is preferably in the range of 10 μm to 100 μm, for example. If the wiring line width is too small, the desired conductivity may not be obtained. If the wiring line width is too large, the suspension substrate may not be sufficiently dense. Because.

  Further, the distance between the wirings on the same plane is preferably in the range of 10 μm to 30 μm, for example. If this distance is too small, it is not preferable because it requires high processing accuracy and increases costs. On the other hand, if this distance is too large, the suspension substrate may not be sufficiently dense. Because there is sex.

  The second insulating layer is formed on the first wiring group and the first insulating layer, and includes each wiring configuring the first wiring group and each wiring configuring the second wiring group. Are electrically insulated. In addition, by filling the gaps between the wirings constituting the first wiring group with the second insulating layer, the capacity of capacitive coupling between the wirings can be further increased. The material for the second insulating layer is not particularly limited as long as it has a desired insulating property and dielectric constant, and examples thereof include polyimide. The material of the second insulating layer may be a photosensitive material or a non-photosensitive material. The thickness of the second insulating layer is, for example, in the range of 4 μm to 30 μm between each wiring configuring the first wiring group and each wiring configuring the second wiring group.

  In order to prevent deterioration due to corrosion or the like, it is preferable that each wiring constituting the second wiring group is covered with a cover layer. Moreover, the capacity | capacitance of the capacitive coupling between each wiring can also be enlarged by filling the clearance gap between each wiring which comprises a 2nd wiring group with a cover layer. Examples of the material for the cover layer include polyimide. The material of the cover layer may be a photosensitive material or a non-photosensitive material. The thickness of the cover layer is, for example, in the range of 4 μm to 30 μm on each wiring configuring the second wiring group.

(2) Configuration of Suspension Substrate The suspension substrate according to the first embodiment is greatly characterized in that wiring and via portions are arranged at specific positions. As shown in FIG. 4, the wiring a ₁ is electrically connected to the connection terminal T _α1 . In FIG. 4, the linear wiring a ₁ is formed from the connection terminal T _α1, but the wiring a ₁ may have any shape as long as it is electrically connected to the connection terminal T _α1. Can do. The wiring _{a 1} is formed on the wiring _{a 1,} and by the via _{V AC11} penetrating the second insulating layer, and is electrically connected to the wiring _{c 1.}

Wire _{a 2} is formed on the wiring _{a 2,} and, by the via _{V AC21} penetrating the second insulating layer, and is electrically connected to the wiring _{c 2.} The wiring a ₂ and the wiring c ₂ may be electrically connected via the via portion V _ac21 . Therefore, by the via V _AC21 in a position overlapping with the wiring c ₂ in a plan view are formed, wiring a ₂ and the wiring c ₂ is may be electrically connected, a jumper wire J _c12 in a plan view the via V _AC21 is formed in overlapping positions, by going through the jumper wiring J _c12, wiring a ₂ and the wiring c ₂ may be electrically connected.

The wiring c ₁ and the wiring c ₂ are electrically connected by a jumper wiring J _C12 belonging to the signal wiring C. The jumper wiring J _C12 is arranged so as to intersect with the wiring b ₁ in plan view.

Wire b _1, a connection terminal T _.beta.1 and are electrically connected. As long as the connection terminal T _β1 is electrically connected to the wiring b ₁ , the connection terminal T _β1 may be formed in the first wiring group or the second wiring group. preferable. The wiring b ₁ is formed on the wiring b ₁ , is formed on the side opposite to the connection terminal T _β1 in plan view with the jumper wiring J _c12 as a boundary, and a via portion that penetrates the second insulating layer V _bd11 is electrically connected to the wiring d ₁ .

In the first embodiment, the via portion used for the wiring located at the outermost part of the interleaved wiring structure can be arranged relatively freely. In FIG. 5, the via portion V _ac11 that is located at the outermost part of the interleaved wiring structure and electrically connects the wiring a ₁ and the wiring c ₁ is connected to the connection terminal T _α1 in plan view with the jumper wiring J _c12 as a boundary. Is formed. Although not shown, the via portion V _ac11 may be formed on the side opposite to the connection terminal T _α1 in plan view with the jumper wiring J _c12 as a boundary. That is, the via portion V _ac11 can be formed at an arbitrary position on the wiring a ₁ .

Similarly, in FIG. 5, located on the outermost interleave wiring structure, the via V _BD21 the wiring b ₂ and the wiring d ₂ electrically connecting, with jumper wires J _c12 bordering, connected in a plan view terminal It is formed over the wiring _{b 1} of T _.beta.1 side. Although not shown, the via V _BD21 may be formed on the jumper wiring J _b12, it may be formed on the wiring b _2.

In the first embodiment, each of the signal wirings A to D may have three or more wirings. 6, wiring _{a 3} is formed on the wiring _{a 3,} and by the via _{V AC31} penetrating the second insulating layer, and is electrically connected to the wiring _{c 3.} The wiring c ₂ and the wiring c ₃ are electrically connected by a jumper wiring J _C23 belonging to the signal wiring C. The wiring b ₂ is formed on the wiring b ₂ , is formed on the side opposite to the connection terminal T _β1 in plan view with the jumper wiring J _c23 as a boundary, and the via portion V _bd21 that penetrates the second insulating layer. by being electrically connected to the wiring d _2. FIG. 6 is an example in which each of the signal wirings A to D has three wirings, but the same applies to the case where each of the signal wirings A to D has four or more wirings.

Further, as shown in FIG. 6, the wirings a _{3 to} d ₃ may be formed on the side opposite to the wirings a _{1 to} d ₁ with reference to the wirings a _{2 to} d ₂ , as shown in FIG. In addition, the wirings a _{1 to} d ₁ may be formed on the side opposite to the wirings a _{2 to} d ₂ with reference to the wirings a _{1 to} d ₁ . In this case, for example, the connection terminal can be provided near the center in the width direction of the interleaved wiring structure, and there is an advantage that the degree of freedom in wiring design is high. 7, wiring _{a 3} is formed on the wiring _{a 3,} and by the via _{V AC31} penetrating the second insulating layer, and is electrically connected to the wiring _{c 3.} The wiring c ₁ and the wiring c ₃ are electrically connected by a jumper wiring J _C13 belonging to the signal wiring C. The wiring b ₁ is formed by the via portion V _b1 , the jumper wiring J _b13 belonging to the second wiring group, and the via portion V _b3 formed on the connection terminal T _β1 side in a plan view with the jumper wiring J _c13 as a boundary. b ₃ and are electrically connected. Wire _{b 3} is formed on the wiring _{b 3,} a boundary of the jumper wiring _{J c13,} and the connection terminals T _.beta.1 in plan view are formed on the opposite side, and the via _{V Bd31} penetrating the second insulating layer by being electrically connected to the wiring d _3.

  In the first embodiment, the wiring and the via part are arranged at specific positions on at least one of the head side and the tail side. In particular, in the first embodiment, it is preferable that the wiring and the via portion are arranged at specific positions on both the head side and the tail side. This is because transmission loss due to jumper wiring on the metal supporting board can be further suppressed.

Specifically, as shown in FIG. 8, the wiring b ₂ are electrically connected to the connecting terminal T _.beta.2. Furthermore, wiring _{b 2} is formed on the wiring _{b 2,} and by the via _{V BD22} penetrating the second insulating layer and connected to the wiring _{d 2} electrically. Wire _{b 1} is formed on the wiring _{b 1,} and by the via _{V BD12} penetrating the second insulating layer, and is electrically connected to the wiring _{d 1.} The wiring d ₁ and the wiring d ₂ are electrically connected by a jumper wiring J _d12 belonging to the signal wiring D. Wire a ₂ is electrically connected to the connecting terminal T _{[alpha] 2.} Furthermore, the wiring a ₂ is formed on the wiring a ₂ , is formed on the side opposite to the connection terminal T _α2 in plan view with the jumper wiring J _d12 as a boundary, and a via portion that penetrates the second insulating layer the V _{AC 22,} and is electrically connected to the wiring _{c 2.}

  Next, the manufacturing method of the suspension substrate of the first embodiment will be described. The manufacturing method of the suspension substrate of the first embodiment is not particularly limited as long as it is a method capable of obtaining the suspension substrate having the above-described configuration.

  FIG. 9 is a schematic cross-sectional view showing an example of a method for manufacturing a suspension substrate according to the first embodiment, and corresponds to a cross-sectional view taken along line AA in FIG. In FIG. 9, first, a laminated member in which the metal supporting member 1A, the insulating member 2A, and the conductor member 3A are laminated in this order is prepared (FIG. 9A). Next, the conductive member 3A is patterned by wet etching to form a first wiring group 3x (FIG. 9B). Next, a second insulating layer 2y is formed on the first wiring group 3x and the insulating member 2A (FIG. 9C). Next, although not shown, the insulating member 2A is patterned by wet etching to form the first insulating layer 2x. Next, a seed layer (not shown) is formed on the entire surface of the second insulating layer 2y side by sputtering, a predetermined resist pattern is formed on the surface of the seed layer formed on the entire surface, and the resist pattern is exposed. A second wiring group 3y is formed in the portion by electrolytic plating (FIG. 9D). In FIG. 9D, the via portion penetrating the second insulating layer 2y and the second wiring group 3y are continuously formed, but the via portion penetrating the second insulating layer 2y. May be formed using a material (for example, plating such as Ni plating) different from that of the second wiring group 3y. Next, the cover layer 4 is formed so as to cover the second wiring group 3y (FIG. 9E). Finally, the outer shape of the metal support member 1A is processed to form the metal support substrate 1 (FIG. 9 (f)). Thereby, a suspension substrate is obtained.

2. Second Embodiment A suspension substrate according to the second embodiment includes a metal supporting substrate, a first insulating layer formed on the metal supporting substrate, and a first insulating layer formed on the first insulating layer. A wiring group, a second wiring layer formed on the first wiring group and the first insulating layer, a second wiring group formed on the second insulating layer, The first wiring group includes a signal wiring A having a plurality of wirings electrically connected to each other, and the signal wiring A is electrically independent and electrically connected to each other. The signal wirings B having a plurality of connected wirings are alternately arranged in a plane, and the second wiring group includes the signal wirings C having a plurality of wirings electrically connected to each other, The signal wiring C is electrically independent and has a plurality of wirings electrically connected to each other. The signal wirings D are alternately arranged in a plane, the signal wiring A and the signal wiring C are opposed to each other through the second insulating layer, and the signal wiring B and the signal wiring D are The first wiring group and the second wiring group are arranged so as to face each other through the second insulating layer, and the signal wirings A to D are respectively connected to the wirings a _{1 to} d ₁ and the wiring a. _{2 to} d ₂ , the wiring c ₁ is electrically connected to the connection terminal T _α1, and is further formed on the wiring a ₁ , and further passes through the second insulating layer. the _AC11 is the wiring _{a 1} and electrically connected, the wiring _{c 2} is formed on the wiring _{a 2,} and, by the via _{V AC21} penetrating the second insulating layer, the wiring _{a 2} The wiring a ₁ and the wiring a ₂ are electrically connected to the signal wiring. The wiring d ₁ is electrically connected by a jumper wiring J _a12 belonging to A, and the wiring d ₁ is electrically connected to the connection terminal T _β1 and further formed on the wiring b ₁ , with the jumper wiring J _a12 as a boundary. In the plan view, it is formed on the side opposite to the connection terminal T _β1 and is electrically connected to the wiring b ₁ by a via portion V _bd11 penetrating the second insulating layer. To do.

  Note that the suspension substrate of the second embodiment and the suspension substrate of the first embodiment are in a relationship in which the first wiring group and the second wiring group are interchanged.

  According to the second embodiment, by arranging the wiring and the via portion at a specific position, a desired wiring structure can be obtained without using the jumper wiring of the metal supporting board. Thereby, it can be set as the board | substrate for suspensions which suppressed the transmission loss. Further, according to the second embodiment, the signal wiring A and the signal wiring C are opposed to each other through the second insulating layer, and the signal wiring B and the signal wiring D are opposed to each other through the second insulating layer. In addition, by arranging the first wiring group and the second wiring group, it is possible to reduce the differential impedance while keeping the bandwidth of the high-frequency signal wide while suppressing an increase in the wiring area. it can.

(1) Suspension Substrate Member The suspension substrate member of the second embodiment is the same as the suspension substrate member of the first embodiment described above, and is not described here.

(2) Configuration of Suspension Substrate The suspension substrate of the second embodiment is greatly characterized in that the wiring and via portions are arranged at specific positions. Since the suspension substrate of the second embodiment and the suspension substrate of the first embodiment are in a relationship in which the first wiring group and the second wiring group are interchanged, basically the first embodiment is the same as the first embodiment. Although it is the same as that of the content described, a typical example is demonstrated using FIGS.

10, the wiring _{c 1} is electrically connected to the connecting terminal T _{[alpha] 1.} Further, the wiring _{c 1} is formed on the wiring _{a 1,} and by the via _{V AC11} penetrating the second insulating layer, and is electrically connected to the wiring _{a 1.} Wiring _{c 2} is formed on the wiring _{a 2,} and, by the via _{V AC21} penetrating the second insulating layer, and is electrically connected to the wiring _{a 2.} The wiring a ₁ and the wiring a ₂ are electrically connected by a jumper wiring J _a12 belonging to the signal wiring A. Wire d _1, a connection terminal T _.beta.1 is electrically connected to the. Further, the wiring d ₁ is formed on the wiring b _1, as a border jumper wires J _a12, and the connection terminals T _.beta.1 in plan view are formed on the opposite side, and, via extending through the second insulating layer The wiring b ₁ is electrically connected by V _bd11 . Wire _{d 2} is formed on the wiring _{b 2,} and by the via _{V BD21} penetrating the second insulating layer, and is electrically connected to the wiring _{b 2.}

11, the wiring _{c 3} is formed on the wiring _{a 3,} and by the via _{V AC31} penetrating the second insulating layer, are wired _{a 3} electrically connected. The wiring a ₂ and the wiring a ₃ are electrically connected by a jumper wiring J _a23 belonging to the signal wiring A. The wiring d ₂ is formed on the wiring b ₂ , is formed on the side opposite to the connection terminal T _β1 in a plan view with the jumper wiring J _a23 as a boundary, and the via portion V _bd21 that penetrates the second insulating layer. by being electrically connected to the wiring b _2.

12, the wiring _{c 3} is formed on the wiring _{a 3,} and by the via _{V AC31} penetrating the second insulating layer, are wired _{a 3} electrically connected. In addition, the wiring a ₁ and the wiring a ₃ are electrically connected by a jumper wiring J _a13 belonging to the signal wiring C. Further, the wiring d ₁ is formed by the via portion V _d1 , the jumper wiring J _d13 belonging to the first wiring group, and the via portion V _d3 formed on the connection terminal T _β1 side in a plan view with the jumper wiring J _a13 as a boundary. Are electrically connected to the wiring d ₃ . The wiring d ₃ is formed on the wiring b ₃ , is formed on the side opposite to the connection terminal T _β1 in plan view with the jumper wiring J _a13 as a boundary, and the via portion V _bd31 that penetrates the second insulating layer. by being electrically connected to the wiring b _3.

13, the wiring _{d 2} is electrically connected to the connecting terminal T _.beta.2. Further, the wiring _{d 2,} the wiring _{b 2} is formed on, and the via portion _{V BD22} penetrating the second insulating layer, are wired _{b 2} and electrically connected. Wire _{d 1} is formed on the wiring _{b 1,} and by the via _{V BD12} penetrating the second insulating layer, and is electrically connected to the wiring _{b 1.} The wiring b ₁ and the wiring b ₂ are electrically connected by a jumper wiring J _b12 belonging to the signal wiring B. Wiring c ₂ is electrically connected to the connecting terminal T _{[alpha] 2.} Furthermore, the wiring c ₂ is formed on the wiring a ₂ , is formed on the side opposite to the connection terminal T _α2 in plan view with the jumper wiring J _b12 as a boundary, and a via portion that penetrates the second insulating layer the V _{AC 22,} and is electrically connected to the wiring _{a 2.}

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

  FIG. 14 is a schematic plan view showing an example of the suspension of the present invention. A suspension 300 shown in FIG. 14 includes the suspension substrate 100 described above and a load beam 200 provided on the surface of the suspension substrate 100 on the metal support substrate side.

  According to the present invention, by using the above-described suspension substrate, a suspension in which transmission loss is suppressed can be obtained. Furthermore, by using the above-described suspension substrate, it is possible to reduce the differential impedance while keeping the bandwidth of the high-frequency signal wide while suppressing an increase in the wiring area.

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

C. Next, the suspension with an element of the present invention will be described. A suspension with an element of the present invention includes the above-described suspension and a recording / reproducing element disposed on the suspension.

  FIG. 15 is a schematic plan view showing an example of the suspension with an element of the present invention. 15 includes the suspension 300 described above and the recording / reproducing element 301 mounted on the suspension 300 (recording / reproducing element mounting region 101 of the suspension substrate 100).

  According to the present invention, by using the above-described suspension, it is possible to provide a suspension with an element in which transmission loss is suppressed. Further, by using the suspension described above, it is possible to reduce the differential impedance while keeping the bandwidth of the high-frequency signal wide while suppressing an increase in the wiring area.

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

  The heat assisting element is not particularly limited as long as it can assist recording by the recording / reproducing element with heat. Among them, the heat assist element in the present invention is preferably an element using light. This is because heat-assisted recording by an optical dominant recording method can be performed. Examples of the heat assist element using light include a semiconductor laser diode element. The semiconductor laser diode element may be a pn-type element, or a pnp-type or npn-type element.

  The actuator element usually corresponds to a microactuator or a milliactuator. Examples of the actuator element include a piezo element. As the piezo element, for example, one made of PZT can be cited. By using the expansion / contraction response of the piezo element, positioning can be performed in submicron units. In addition, the piezoelectric element has advantages such as high energy efficiency, large load resistance, fast response, no wear deterioration, and no magnetic field. In the present invention, a single bipolar piezo element may be used. Two unipolar piezoelectric elements may be used.

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

  FIG. 16 is a schematic plan view showing an example of the hard disk drive of the present invention. A hard disk drive 500 shown in FIG. 16 includes the above-described suspension 400 with an element, a disk 401 on which data is written and read by the suspension 400 with an element, a spindle motor 402 that rotates the disk 401, and the elements of the suspension 400 with an element. Arm 403 and voice coil motor 404, and a case 405 for sealing the above members.

  According to the present invention, a hard disk drive with reduced transmission loss can be obtained by using the above-described suspension with an element. Further, by using the above-described suspension with an element, it is possible to reduce the differential impedance while keeping a wide bandwidth of the high-frequency signal while suppressing an increase in the wiring area.

  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 technical idea described in the claims of the present invention has substantially the same configuration and exhibits the same function and effect regardless of the case. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be described more specifically with reference to examples.

With respect to the suspension substrate according to the present invention having a configuration in which the interleaved wiring structure is laminated in two layers, and the conventional suspension substrate having the interleaved wiring structure only in a single layer, the target differential impedance is 2Ω of 30Ω and 20Ω. The thickness of the wiring, the width of the wiring, and the width between adjacent wirings are optimized by simulation under the condition that the wiring area is set to be approximately the same under the condition that the wiring area is approximately the same. The width was calculated.
In each of Examples 1 and 2 and Comparative Examples 1 and 2, polyimide having a relative dielectric constant of 3.0 was used for each insulating layer, and the thickness of the first insulating layer was 10 μm. Also, copper was used as the material for each wiring.
The results are as follows.

[Example 1]
In the suspension substrate 10 according to the present invention having the configuration shown in FIG. 17, the simulation was performed with a target differential impedance of 30Ω. As a result, the −3 dB bandwidth at a wiring length of 40 mm obtained under the following conditions was 8.2 GHz. It was. The obtained differential impedance value was 31.0Ω.
<Simulation conditions>
First wiring group (four wirings 13a to 13d):
In each case, the thickness is 5 μm, the width (W1) is 25 μm, and the width between each wiring (S1) is 15 μm.
Second wiring group (four wirings 15a to 15d):
In each case, the thickness is 5 μm, the width (W1) is 25 μm, and the width between each wiring (S1) is 15 μm.
Second insulating layer 14: thickness on wiring (D11) 5 μm
Third insulating layer 16: thickness on wiring (D12) 5 μm
Spacing between the opening end of the metal support substrate 11 and the first wiring group: Spacing (LS1) 25 μm

[Comparative Example 1]
In the conventional suspension substrate 120 having the configuration shown in FIG. 18, simulation was performed with a target differential impedance of 30Ω. As a result, the −3 dB bandwidth at a wiring length of 40 mm obtained under the following conditions was 6.7 GHz. The obtained differential impedance value was 31.3Ω.
<Simulation conditions>
Wirings 113a to 113d (four wires):
In any case, the thickness is 10 μm, the width (W2) is 28 μm, the width between each wiring (S2) is 12 μm, the second insulating layer 114: the thickness on the wiring (D2) is 5 μm
Spacing between opening end of metal support substrate 111 and wiring group: Spacing (LS2) 25 μm

[Example 2]
In the suspension substrate 20 according to the present invention having the configuration shown in FIG. 19, the simulation was performed with a target differential impedance of 20Ω, and as a result, the −3 dB bandwidth at a wiring length of 40 mm obtained under the following conditions was 7.2 GHz. It was. The obtained differential impedance value was 19.7Ω.
<Simulation conditions>
First wiring group (six wirings 23a to 23f):
In any case, the thickness is 5 μm, the width (W3) is 25 μm, and the width between each wiring (S3) is 15 μm.
Second wiring group (6 wirings 25a to 25f):
In any case, the thickness is 5 μm, the width (W3) is 25 μm, and the width between each wiring (S3) is 15 μm.
Second insulating layer 14: thickness on wiring (D31) 5 μm
Third insulating layer 16: thickness on wiring (D32) 5 μm
Spacing between the opening end of the metal support substrate 11 and the first wiring group: Spacing (LS3) 25 μm

[Comparative Example 2]
In the conventional suspension substrate 140 having the configuration shown in FIG. 20, simulation was performed with a target differential impedance of 20Ω. As a result, the −3 dB bandwidth at a wiring length of 40 mm obtained under the following conditions was 5.6 GHz. The obtained differential impedance value was 19.5Ω.
<Simulation conditions>
Wirings 123a to 123f (six):
In any case, the thickness is 10 μm, the width (W4) is 28 μm,
Width between each wiring (S4) 12μm
Second insulating layer 114: thickness on wiring (D4) 5 μm
Interval between the opening end of the metal support substrate 111 and the wiring group: Interval (LS4) 25 μm

The above result will be described.
First, when the required differential impedance is 30Ω, the conventional interleaved wiring structure composed of four wirings can be achieved with only a single layer.
However, for example, as shown in Comparative Example 1, the width (S2) between the wirings is 12 μm, whereas the wiring thickness is 10 μm, which is twice that of Example 1, and processing with a high aspect ratio is required. As a result, the manufacturing is difficult, and the obtained bandwidth is 6.7 GHz, which is inferior to that of Example 1.
On the other hand, as in the present invention, the interleaved wiring structure is laminated in two layers, and each first signal wiring in the lower layer (first wiring group) and each first signal wiring in the upper layer (second wiring group) are respectively The second signal wiring in the lower layer (first wiring group) and the second signal wiring in the upper layer (second wiring group) are arranged so as to face each other with the insulating layer interposed therebetween. In the configuration, as shown in Example 1, even when the wiring region is almost the same as that of Comparative Example 1, the width (S1) between the wirings is 12 μm, whereas the thickness of the wiring is 5 μm, which is a comparative example. Since 1/2 of 1 is sufficient, the problem of manufacturing difficulty can be solved. Furthermore, the obtained bandwidth could hold a wide value of 8.2 GHz, which was a result superior to that of Comparative Example 1.

Next, when the required differential impedance is 20Ω, it is difficult to achieve with a conventional configuration having an interleaved wiring structure consisting of four wirings only in a single layer, for example, having an interleaved wiring structure only in a single layer. The configuration required 6 wires.
However, in the configuration having the conventional interleaved wiring structure only in a single layer, as shown in Comparative Example 2, the width (S4) between the wirings is 12 μm, whereas the wiring thickness is 10 μm, which is 2 of Example 2. The value is doubled, and processing with a high aspect ratio is required, which makes manufacturing difficult. The obtained bandwidth is 5.6 GHz, which is inferior to that of Example 2.
On the other hand, as in the present invention, the interleaved wiring structure is laminated in two layers, and each first signal wiring in the lower layer (first wiring group) and each first signal wiring in the upper layer (second wiring group) are respectively The second signal wiring in the lower layer (first wiring group) and the second signal wiring in the upper layer (second wiring group) are arranged so as to face each other with the insulating layer interposed therebetween. In the configuration, as shown in Example 2, even when the wiring area is almost the same as that of Comparative Example 2, the width (S3) between the wirings is 15 μm, whereas the thickness of the wiring is 5 μm. Since 1/2 of 1 is sufficient, the problem of manufacturing difficulty can be solved. Furthermore, the obtained bandwidth could hold a wide value of 7.2 GHz, which was a result superior to that of Comparative Example 2.

  DESCRIPTION OF SYMBOLS 1 ... Metal support substrate, 2x ... 1st insulating layer, 2y ... 2nd insulating layer, 3x ... 1st wiring group, 3y ... 2nd wiring group, 4 ... Cover layer

Claims (7)

A metal support substrate; a first insulating layer formed on the metal support substrate; a first wiring group formed on the first insulating layer; the first wiring group; A suspension substrate having a second insulating layer formed on one insulating layer and a second wiring group formed on the second insulating layer,
The first wiring group includes a signal wiring A having a plurality of wirings that are electrically connected to each other, and a signal having a plurality of wirings that are electrically independent from each other and electrically connected to each other. Wiring B is alternately arranged in a plane,
The second wiring group includes a signal wiring C having a plurality of wirings electrically connected to each other, and a signal having a plurality of wirings electrically independent from each other and electrically connected to each other. Wirings D are alternately arranged in a plane,
The signal wiring A and the signal wiring C are opposed to each other through the second insulating layer, and the signal wiring B and the signal wiring D are opposed to each other through the second insulating layer. 1 wiring group and the second wiring group are arranged,
The signal wirings A to D have wirings a _{1 to} d ₁ and wirings a _{2 to} d ₂ , respectively.
The wiring a ₁ is electrically connected to the connection terminal T _α1, and is formed on the wiring a ₁ , and is connected to the wiring c ₁ by a via portion V _ac11 penetrating the second insulating layer. Electrically connected,
The wiring a ₂ is electrically connected to the wiring c ₂ by a via portion V _ac21 formed on the wiring a ₂ and penetrating the second insulating layer.
The wiring c ₁ and the wiring c ₂ are electrically connected by a jumper wiring J _C12 belonging to the signal wiring C,
The wiring b ₁ is electrically connected to the connection terminal T _β1 , further formed on the wiring b _{1, and} on the side opposite to the connection terminal T _β1 in plan view with the jumper wiring J _c12 as a boundary. It is formed, and the second by a via portion V _{BD 11} passing through the insulating layer, the substrate for suspension, characterized in that connected the wiring d ₁ electrically. The wiring b ₂ is electrically connected to the connection terminal T _β2, and is further formed on the wiring b ₂ and is connected to the wiring d ₂ by a via portion V _bd22 that penetrates the second insulating layer. Electrically connected,
The wiring b ₁ is electrically connected to the wiring d ₁ by a via portion V _bd12 formed on the wiring b ₁ and penetrating the second insulating layer.
The wiring d ₁ and the wiring d ₂ are electrically connected by a jumper wiring J _d12 belonging to the signal wiring D,
The wiring a ₂ is electrically connected to the connection terminal T _α2 , further formed on the wiring a _{2, and} on the side opposite to the connection terminal T _α2 in plan view with the jumper wiring J _d12 as a boundary. It is formed, and the second by a via portion V _{AC 22} passing through the insulating layer, suspension substrate according to claim 1, characterized in that connected the wiring c ₂ and electrically. A metal support substrate; a first insulating layer formed on the metal support substrate; a first wiring group formed on the first insulating layer; the first wiring group; A suspension substrate having a second insulating layer formed on one insulating layer and a second wiring group formed on the second insulating layer,
The first wiring group includes a signal wiring A having a plurality of wirings that are electrically connected to each other, and a signal having a plurality of wirings that are electrically independent from each other and electrically connected to each other. Wiring B is alternately arranged in a plane,
The second wiring group includes a signal wiring C having a plurality of wirings electrically connected to each other, and a signal having a plurality of wirings electrically independent from each other and electrically connected to each other. Wirings D are alternately arranged in a plane,
The signal wiring A and the signal wiring C are opposed to each other through the second insulating layer, and the signal wiring B and the signal wiring D are opposed to each other through the second insulating layer. 1 wiring group and the second wiring group are arranged,
The signal wirings A to D have wirings a _{1 to} d ₁ and wirings a _{2 to} d ₂ , respectively.
The wiring c ₁ is connected to the connection terminals T _{[alpha] 1} and electrically, furthermore, is formed on the wiring a _1, and by the via V _AC11 which penetrates the second insulating layer, and the wiring a ₁ Electrically connected,
The wiring c ₂ is electrically connected to the wiring a ₂ by a via portion V _ac21 formed on the wiring a ₂ and penetrating the second insulating layer.
The wiring a ₁ and the wiring a ₂ are electrically connected by a jumper wiring J _a12 belonging to the signal wiring A,
The wiring d ₁ is electrically connected to the connection terminal T _β1 , further formed on the wiring b _{1, and} on the side opposite to the connection terminal T _β1 in plan view with the jumper wiring J _a12 as a boundary. A suspension substrate, which is formed and is electrically connected to the wiring b ₁ by a via portion V _bd11 penetrating the second insulating layer. The wiring d _2, a connection terminal T _.beta.2 and is electrically connected, further, are formed on the wiring b _2, and by the via V _BD22 which penetrates the second insulating layer, and the wiring b ₂ Electrically connected,
The wiring d ₁ is electrically connected to the wiring b ₁ by a via portion V _bd12 formed on the wiring b ₁ and penetrating the second insulating layer.
The wiring b ₁ and the wiring b ₂ are electrically connected by a jumper wiring J _b12 belonging to the signal wiring B,
The wiring c ₂ is connected a connection terminal T _{[alpha] 2} and electrically, furthermore, is formed on the wiring a _2, a boundary the jumper wiring J _b12, on the opposite side to the connection terminal T _{[alpha] 2} in a plan view is formed, and the second by a via portion V _{AC 22} passing through the insulating layer, suspension substrate according to claim 3, characterized in that it is the wiring a ₂ electrically connected.   A suspension board comprising: the suspension board according to any one of claims 1 to 4; and a load beam provided on a surface of the suspension board on the metal support board side. .   6. A suspension with an element, comprising: the suspension according to claim 5; and a recording / reproducing element disposed on the suspension.   A hard disk drive comprising the suspension with an element according to claim 6.

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