JP2014044785A - Suspension substrate, suspension, suspension with head, and hard disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension substrate, a suspension, a suspension with a head, and a hard disk drive that are able to reduce differential impedance while restricting an increase of a wiring area and that are able to stably hold the band width of a high frequency signal.SOLUTION: The foregoing objects can be achieved by configuring a suspension substrate as described below. A first wire group composing an interleave wire structure is formed on a first insulation layer formed on a metal support substrate. A second wire group composing an interleave wire structure is arranged in a layer on the first wire group via a second insulation layer. The wires of the second wire group, to which electric signals of the same phase are transmitted, are arranged on the corresponding wires of the first wire group. The distance between the respective lateral faces of the wires of the second wire group is made greater than the distance between the respective lateral faces of the wires of the first wire group.

Description

  The present invention mainly relates to a suspension board on which a magnetic head slider used for a hard disk drive (HDD) and writing and reading data to and from a disk storing data is mounted.

  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.

In general, a hard disk drive (HDD) includes a suspension substrate on which 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 a spring property, 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. The differential impedance is required to be lowered from the viewpoint of impedance matching as the impedance of the magnetic head and the preamplifier is lowered.

  As a wiring structure capable of reducing this differential impedance, a pair of wirings that transmit a first electrical signal and wirings that transmit 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. 11A, the first insulating layer 112 formed on the metal support substrate 111A may be formed on each other. A plurality of electrically connected first signal wires (eg, 113a and 113c) and the first signal wire are electrically independent, and a plurality of second signal wires (eg, 113b, 113b, 113d) are alternately arranged in a plane, and a method of forming the second insulating layer 114 on these wirings (113a, 113b, 113c, 113d) has been proposed (for example, Patent Document 2). .
The first signal wiring and the second signal wiring constitute a pair of differential wirings, and are transmitted to the electric signal (first electric signal) transmitted to the first signal wiring and the second signal wiring. Are opposite in phase to each other.

However, in the configuration shown in FIG. 11A, 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. 11 (b), the metal support substrate that overlaps 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. 12 is an explanatory diagram showing a circuit configuration of interleave wiring of the suspension substrate shown in FIG. 11 (a) or (b).
As shown in FIG. 12, 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 wiring that electrically connects the connection terminal 131b and the connection terminal 131d. The first signal wiring branches into a wiring 113a and a wiring 113c at a branching point 132a. Similarly, the second signal wiring has a wiring 113b and a wiring at a branching point 132b. The wirings branched to 113d are arranged in parallel in the order of 113a, 113b, 113c, and 113d from the left end of the drawing so that the wirings for transmitting electrical signals having opposite phases to each other are adjacent to each other.
Then, the wirings 113a and 113c through which electrical signals having the same phase are transmitted are electrically connected by connection lines 134a via connection vias 133a and 133b provided in the second insulating layer 114, respectively. Similarly, the wirings 113b and 113d are electrically connected by a connection line 134b via connection vias 133c and 133d.

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

In order to cope with further lower impedance in the suspension board 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. A method 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. 11 (a) or (b), the side surfaces of the wirings having opposite phases are opposed to each other to form capacitive coupling between the wirings. 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. 13, wirings 213a and 213b having opposite phases to each other are stacked via the second insulating layer 214, and the 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 stacked via an insulating layer, if the insulating layer between the wirings is made a thin film in order to reduce the overall thickness of the suspension board, It has been found that the problem that the high frequency characteristics deteriorate due to the interaction between the upper and lower anti-phase wirings (more specifically, the bandwidth of the transmission characteristics becomes narrower) occurs.

  In contrast, for example, as shown in FIG. 14A, the inventor has formed each wiring (313a, 313b, 313c) of the first wiring group constituting the interleaved wiring structure on the first insulating layer 312. 313d), and the wirings (315a, 315b, 315c, 315d) of the second wiring group constituting the interleaved wiring structure are stacked on the first wiring group via the second insulating layer 314. And it discovered that the said subject could be solved by arranging each wiring of the said 2nd wiring group to which the electrical signal of the same phase is each transmitted on each wiring of the said 1st wiring group.

  However, as a new problem, for example, as shown in FIG. 14B, the arrangement position of each wiring in the second wiring group is displaced from the position of each wiring in the first wiring group. When it occurs, it has been found that the wirings for transmitting electrical signals having opposite phases to each other approach each other, so that the bandwidth is reduced.

The above will be described in more detail with reference to FIGS. FIG. 15A is a schematic plan view for explaining the overlapping state of each wiring shown in FIG. 14A, and FIG. 15B shows the overlapping state of each wiring shown in FIG. It is a schematic plan view to explain.
For example, as shown in FIG. 14A and FIG. 15A, each center of the first signal wiring (for example, 315a) and the second signal wiring (for example, 315b) adjacent to each other in the second wiring group. The distance (P302) between the lines (for example, C315a and C315b shown in FIG. 15A) is the first signal line (for example, 313a) and the second signal line (for example, adjacent to each other in the first line group). 313b) is equal to a distance (P301) between each center line and the side surfaces of the first signal wiring (for example, 315a) and the second signal wiring (for example, 315b) that are opposite to each other in the second wiring group. The distance (S302) between the side surface of the first signal wiring (for example, 313a) and the second signal wiring (for example, 313b) facing each other in the first wiring group. In the multilayer wiring structure designed to be equal to the distance between the side surfaces (S301), as shown in FIGS. 14B and 15B, the wirings of the second wiring group are arranged. When the position of the first wiring group has a positional shift (shift amount OS301) in the width direction of each wiring (rightward in the drawing) with respect to the position of each wiring of the first wiring group, for example, The wiring 315a approaches the wiring 313b of the first wiring group.
More specifically, for example, as shown in FIG. 14A and FIG. 15A, the plane direction of the wiring 315a of the second wiring group and the wiring 313b of the first wiring group (second The interval (horizontal distance) in the plane direction of the insulating layer 314 is S301 (or S302) when there is no misalignment, but as shown in FIGS. 14B and 15B, When a positional deviation (deviation amount OS301) occurs, the distance (in the plane direction of the second insulating layer 314) between the wiring 315a of the second wiring group and the wiring 313b of the first wiring group (the surface direction of the second insulating layer 314) The distance in the horizontal direction) is Z312 which is a smaller value than the above S301 (or S302). Z312 corresponds to a value obtained by subtracting the OS 301 from S301 (or S302).
The wiring 315a of the second wiring group and the wiring 313b of the first wiring group are wirings through which electrical signals having opposite phases are transmitted, so that the bandwidth is narrowed. Will occur.

  The present invention has been made in view of the above circumstances, and can reduce the differential impedance while suppressing an increase in the wiring area, and can stably maintain the bandwidth of the high-frequency signal. An object is to provide a suspension substrate, a suspension, a suspension with a head, and a hard disk drive.

  As a result of various studies, the present inventor has formed the first wiring group constituting the interleaved wiring structure on the first insulating layer formed on the metal supporting board as the structure of the suspension substrate. 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 having the same phase is transmitted on each wiring of the first wiring group. Each wiring of the second wiring group is arranged, and the distance between the side surfaces of each wiring of the second wiring group is made larger than the distance between the side surfaces of each wiring of the first wiring group. Thus, the present invention has been completed by finding that the above problems can be solved.

  That is, the invention according to claim 1 of the present invention includes 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, A suspension board having the first wiring group and the second wiring group, wherein the first signal wiring and the plurality of first signal wirings electrically connected to each other are electrically independent of each other. A plurality of second signal wirings electrically connected to each other in a plane and alternately arranged, and the first signal wirings of the first wiring group and the first signal wirings of the second wiring group. One signal wiring is opposed to the second insulating layer through the second insulating layer, and the second signal wiring of the first wiring group and the second signal wiring The first wiring group and the second wiring group are arranged so that the second signal wiring of the line group is opposed to the second signal wiring through the second insulating layer. The distance between the center lines of the first signal wiring and the second signal wiring adjacent to each other is the distance between the center lines of the first signal wiring and the second signal wiring adjacent to each other in the first wiring group. The distance between the side surface of the first signal wiring and the side surface of the second signal wiring that are equal to each other in the second wiring group is equal to the distance between the first signal wiring and the second signal wiring in the second wiring group. The center lines of the first signal wiring and the second signal wiring that are larger than the distance between the side surface of one signal wiring and the side surface of the second signal wiring and are adjacent to each other in the second wiring group. Suspension characterized by being smaller than the distance between Substrate.

  According to a second aspect of the present invention, in the second wiring group, a distance between a side surface of the first signal wiring and a side surface of the second signal wiring facing each other, and the first wiring A value of ½ of the difference between the distance between the side surface of the first signal wiring and the side surface of the second signal wiring that face each other in the group is the second value that opposes through the second insulating layer. The same distance as the distance in the surface direction of the second insulating layer of the center lines of the first signal wiring of the first wiring group and the first signal wiring of the first wiring group, or the second wiring 2. A value larger than a distance in a surface direction of the second insulating layer of each central line of the first signal wiring of the group and the first signal wiring of the first wiring group. It is a board | substrate for suspensions as described in above.

  According to a third aspect of the present invention, the thickness of the first signal wiring and the second signal wiring in the second wiring group is such that the thickness of the first signal wiring and the second signal wiring in the first wiring group is the same. The suspension substrate according to claim 1 or 2, wherein the suspension substrate is larger than a thickness of the two signal wirings.

  In the invention according to claim 4 of the present invention, the metal support substrate has an opening width larger than the width of the region occupied by the first wiring group at a position overlapping the first wiring group in plan view. The suspension substrate according to any one of claims 1 to 3, wherein an opening having a gap is formed.

  The invention according to claim 5 of the present invention is characterized in that a third insulating layer is formed on the second wiring group and the second insulating layer. 5. The suspension substrate according to any one of 4 above.

  An invention according to claim 6 of the present invention is a suspension comprising the suspension substrate according to any one of claims 1 to 5 and a load beam.

  According to a seventh aspect of the present invention, there is provided a suspension with a head comprising the suspension according to the sixth aspect and a magnetic head slider mounted on the suspension.

  According to an eighth aspect of the present invention, there is provided a hard disk drive including the suspension with a head according to the seventh aspect.

In the suspension substrate of the present invention, the differential impedance can be reduced while suppressing an increase in the wiring area, and the bandwidth of the high-frequency signal can be stably maintained.
By using the suspension substrate of the present invention, it is possible to obtain a highly reliable suspension, suspension with a head, and hard disk drive that have low impedance and stable high-frequency signal bandwidth.

It is a schematic plan view showing an example of a suspension substrate according to the present invention. It is AA sectional drawing of the area | region R in FIG. FIG. 3 is a schematic plan view illustrating an overlapping state of each wiring illustrated in FIG. 2. It is explanatory drawing which shows an example of the position shift state of a 1st wiring group and a 2nd wiring group. It is a schematic plan view explaining the overlapping state of each wiring shown in FIG. It is explanatory drawing which shows an example of the circuit structure of the interleave wiring of the board | substrate for suspensions concerning this invention. It is a typical process figure showing an example of a manufacturing method of a substrate for suspensions concerning the present invention. 1 is a schematic plan view showing an example of a suspension according to the present invention. It is a schematic plan view showing an example of a suspension with a head according to the present invention. 1 is a schematic perspective view showing an example of a hard disk drive according to the present invention. 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 suspension 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 which shows the structural example which laminated | stacked the interleave wiring. It is a schematic plan view explaining the overlapping state of each wiring shown in FIG. 3 is a schematic cross-sectional view illustrating a configuration of a suspension substrate in Example 1. FIG. 5 is a schematic cross-sectional view illustrating a configuration of a suspension substrate in Comparative Example 1. FIG.

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

[Suspension substrate]
First, the planar configuration of the suspension substrate of the present invention will be described.
FIG. 1 is a schematic plan view showing an example of a suspension substrate according to the present invention.
As shown in FIG. 1, a suspension substrate 1 according to the present invention has a tongue portion 2 for mounting a magnetic head slider at a tip portion, and is connected to an external reading circuit or writing circuit at a tail side end portion. A wiring group 4 including a write wiring for electrically connecting the magnetic head and the write circuit between the tongue portion 2 and the connection terminal portion 3; The wiring group 5 includes a reading wiring that electrically connects the magnetic head and the reading circuit.

  Here, the wiring group 4 including the write wiring and the wiring group 5 including the reading wiring are respectively used for the suspension substrate in order to avoid mutual electrical influence as much as possible and to maintain the mechanical balance of the suspension substrate. Are arranged along both outer edges in the longitudinal direction.

  Note that the arrangement relationship between the wiring group 4 including the write wiring and the wiring group 5 including the reading wiring in FIG. 1 is an example, and may be another arrangement relationship. For example, the wiring group 5 including the read wiring is disposed at the position of the wiring group 4 including the write wiring in FIG. 1, and the wiring group 4 including the write wiring is disposed at the position of the wiring group 5 including the read wiring. It may be provided.

Next, the laminated wiring configuration of the suspension board according to the present invention will be described.
FIG. 2 is a schematic cross-sectional view showing a configuration example of a suspension substrate according to the present invention, and is a cross-sectional view taken along the line AA of a region R in FIG. FIG. 3 is a schematic plan view for explaining the overlapping state of the wirings shown in FIG. Here, FIG. 2A shows an example in which each of the first wiring group and the second wiring group constituting the interleaved wiring structure is configured by four wirings, and FIG. An example in which each of the first wiring group and the second wiring group is composed of six wirings is shown. 3A is a schematic plan view for explaining the overlapping state of each wiring shown in FIG. 2A, and FIG. 3B shows the overlapping state of each wiring shown in FIG. It is a schematic plan view to explain.

  The suspension substrate according to the present invention includes a metal support substrate, a first insulating layer formed on the metal support substrate, a first wiring group formed on the first insulating layer, A suspension substrate comprising: the first wiring group; a second insulating layer formed on the first insulating layer; and a second wiring group formed on the second insulating layer. In the first wiring group and the second wiring group, a plurality of first signal wirings electrically connected to each other and the first signal wirings are electrically independent from each other and electrically connected to each other. A plurality of second signal wirings connected to each other in a plane and alternately arranged, and the first signal wirings of the first wiring group and the first signal wirings of the second wiring group, Opposite to each other through the second insulating layer, and the second signal wiring and the second wiring of the first wiring group The first wiring group and the second wiring group are arranged so that the second signal wiring is opposed to the second signal wiring through the second insulating layer, and adjacent to each other in the second wiring group. The distance between the center lines of the first signal wiring and the second signal wiring that match each other is between the center lines of the first signal wiring and the second signal wiring that are adjacent to each other in the first wiring group. The distance between the side surface of the first signal wiring and the side surface of the second signal wiring that are equal to the distance and that face each other in the second wiring group is the first signal that faces the other in the first wiring group. The distance between the center line of the first signal wiring and the second signal wiring that is larger than the distance between the side surface of the wiring and the side surface of the second signal wiring and that is adjacent to each other in the second wiring group. It is characterized by being smaller than the distance.

  For example, as shown in FIG. 2A, the suspension substrate 10 of the present invention includes a metal support substrate 11, a first insulating layer 12 formed on the metal support substrate 11, and the first A first wiring group (wirings 13a, 13b, 13c, 13d) formed on the insulating layer 12, and a second insulation formed on the first wiring group and the first insulating layer 12 A layer 14 and a second wiring group (wirings 15a, 15b, 15c, 15d) formed on the second insulating layer 14;

Here, the first wiring group includes a plurality of first signal wirings (for example, 13a and 13c) that are electrically connected to each other, and the first signal wirings are electrically independent, and are electrically connected to each other. A plurality of second signal wirings (for example, 13b and 13d) connected to each other are arranged alternately in a plane, and similarly, the second wiring group includes a plurality of electrical wirings connected to each other. First signal wirings (for example, 15a and 15c) and a plurality of second signal wirings (for example, 15b and 15d) electrically independent from each other and electrically connected to each other. They are arranged alternately in a plane.
Then, the first signal wiring (for example, 13a and 13c) of the first wiring group and the first signal wiring (for example, 15a and 15c) of the second wiring group are the second insulating layer 14. The second signal wiring (for example, 13b and 13d) of the first wiring group and the second signal wiring (for example, 15b and 15d) of the second wiring group are opposed to each other through the second wiring group. The first wiring group and the second wiring group are arranged so as to face each other via the insulating layer.
That is, the first wiring group and the second wiring group respectively constitute the above-described interleaved wiring structure, and each wiring (13a, 13b, 13c, 13d) of the first wiring group, The arrangement relationship with the respective wirings (15a, 15b, 15c, 15d) of the second wiring group is such that the wirings through which electrical signals of the same phase are transmitted are opposed to each other through the second insulating layer 14. Yes.

  Furthermore, in the present invention, as shown in FIGS. 2A and 3A, the first signal wiring (for example, 15a) and the second signal wiring (for example, 15b) that are adjacent to each other in the second wiring group. The distance (P2) between the center lines (for example, C15a and C15b shown in FIG. 3A) of the first signal lines (for example, 13a) and the second line adjacent to each other in the first wiring group. A side surface of the first signal wiring (for example, 15a) and the second signal wiring (for example, 15a) which are equal to the distance (P1) between each central line of the signal wiring (for example, 13b) and face each other in the second wiring group. The distance (S2) between the side surface of 15b) is between the side surface of the first signal wiring (for example, 13a) and the side surface of the second signal wiring (for example, 13b) facing each other in the first wiring group. Distance (S1) And is smaller than the distance (P2) between the center lines of the first signal wiring (for example, 15a) and the second signal wiring (for example, 15b) adjacent to each other in the second wiring group. Is formed.

  Due to such a configuration, the suspension substrate according to the present invention can reduce the differential impedance while suppressing an increase in the wiring area, and can stabilize the bandwidth of the high-frequency signal. Can be held in.

More specifically, in the present invention, since the second wiring group is stacked on the first wiring group, the area occupied by both the wiring groups in a plan view is only the first wiring group. It is the same as the case where it is formed. 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, the differential impedance will be described. In the present invention, 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 eight). ) Has been increased. Therefore, in the present invention, the differential impedance can be reduced to the same extent as in the form in which the first wiring group and the second wiring group are arranged in a plane.

Next, bandwidth will be described. As described above, the positional relationship between each wiring (13a, 13b, 13c, 13d) of the first wiring group and each wiring (15a, 15b, 15c, 15d) of the second wiring group in the present invention. Are configured such that wirings through which electrical signals of the same phase are transmitted are opposed to each other via the second insulating layer 14.
Therefore, when the position of each wiring of the second wiring group is arranged as designed with respect to the position of each wiring of the first wiring group, that is, each wiring of the second wiring group. In order to reduce the overall thickness of the suspension board, the position of the center line of the first wiring group is equal to the position of the center line of each wiring of the first wiring group. Even if the second insulating layer 14 is made a thin film, there arises a problem that the high frequency characteristics deteriorate due to the interaction of the upper and lower wirings (more specifically, the bandwidth of the transmission characteristics becomes narrower). Absent.

  Furthermore, in the present invention, even if the position of each wiring in the second wiring group is displaced from the position of each wiring in the first wiring group, the second wiring The distance (S2) between the side surface of the first signal wiring and the side surface of the second signal wiring that face each other in the group is the same as the distance between the side surface of the first signal wiring and the side surface of the first signal wiring that face each other in the first wiring group. The distance (P2) between the first signal wiring adjacent to each other in the second wiring group and the center line of the second signal wiring is larger than the distance (S1) between the side surfaces of the two signal wirings. ), The distance between the first signal wiring of the first wiring group and the second signal wiring of the second wiring group, and the first wiring group The distance between the second signal wiring and the first signal wiring of the second wiring group Effect of positional deviation Te is reduced, it is possible to suppress that the bandwidth becomes narrow.

The above will be described in more detail with reference to the drawings.
4A shows a suspension substrate according to the present invention, in which the wires (15a, 15b, 15c, 15d) of the second wiring group are distances (P2, S2) shown in FIG. The position of the arrangement is shifted in the width direction of each wiring (right direction in the drawing) with respect to the position of each wiring (13a, 13b, 13c, 13d) of the first wiring group (shift amount OS). It is a schematic sectional drawing which shows the case which has produced. FIG. 5A is a schematic plan view for explaining the overlapping state of the wirings shown in FIG.
The positional deviation between the first wiring group and the second wiring group as described above is caused by a lack of alignment accuracy when forming the second wiring group.

On the other hand, FIG. 4B shows the distance (P402) between the center lines of the first signal wiring (for example, 415a) and the second signal wiring (for example, 415b) adjacent to each other in the second wiring group. , Equal to the distance (P401) between the center lines of the first signal wiring (for example, 413a) and the second signal wiring (for example, 413b) adjacent to each other in the first wiring group, and the second wiring The distance (S402) between the side surface of the first signal wiring (for example, 415a) and the side surface of the second signal wiring (for example, 415b) that face each other in the wiring group is the surface that faces each other in the first wiring group. In the suspension substrate 400b having the same configuration as the distance (S401) between the side surface of the first signal wiring (for example, 413a) and the side surface of the second signal wiring (for example, 413b). While the wirings (415a, 415b, 415c, 415d) of the second wiring group maintain the distance (P402, S402), the arrangement positions thereof are the wirings (413a, 413b, 413c) of the first wiring group. 413d) is a schematic cross-sectional view showing a case where a positional deviation (deviation amount OS) occurs in the width direction of each wiring (right direction in the drawing) with respect to the position 413d). The distance (P401) shown in FIG. 4B is equal to the distance (P1) shown in FIG. 4A, and the distance (S401) shown in FIG. 4B is the distance (S1) shown in FIG. ).
FIG. 5B is a schematic plan view for explaining the overlapping state of the wirings shown in FIG.

  As shown in FIGS. 4A and 4B, the second wiring group is displaced by the same amount (deviation amount OS) in the width direction of each wiring with respect to the first wiring group. In the case, in the suspension substrate 400b shown in FIG. 4B, each wiring of the second wiring group is close to each wiring of the first wiring group through which electrical signals having opposite phases are transmitted. However, in the suspension substrate 10b according to the present invention shown in FIG. 4A, between the side surface of the first signal wiring and the side surface of the second signal wiring that face each other in the second wiring group. Distance (S2) is the distance between the side surface of the first signal wiring and the side surface of the second signal wiring that face each other in the second wiring group in the suspension substrate 400b shown in FIG. S402), the second Each wiring line group may remain at a distance to the first wiring group of each wire to be transmitted electrical signals to be opposite phases.

More specifically, for example, as shown in FIG. 5 (a), the plane direction of the wiring 15a of the second wiring group and the wiring 13b of the first wiring group of the suspension substrate 10b according to the present invention ( The distance (horizontal direction distance Z12) in the plane direction of the second insulating layer 14 is, as shown in FIG. 5B, the wiring 415a of the second wiring group of the suspension substrate 400b and the first wiring. This value is larger than the interval (horizontal direction distance Z412) in the plane direction (surface direction of the second insulating layer 414) of the wiring 413b of the wiring group.
The wiring 15a and the wiring 13b are wirings through which electrical signals having opposite phases are transmitted, and the wiring 415a and the wiring 413b are wirings through which electrical signals having opposite phases are transmitted.

  Therefore, the suspension substrate 10b according to the present invention shown in FIG. 4 (a) has a stable bandwidth compared to the suspension substrate 400b shown in FIG. 4 (b) even when the above-described displacement occurs. Can be held in.

Here, the positional deviation between the first wiring group and the second wiring group as described above is caused by insufficient alignment accuracy when the second wiring group is formed.
Therefore, in the present invention, the distance between the side surface of the first signal wiring and the side surface of the second signal wiring facing each other in the second wiring group (for example, S2 shown in FIG. 4A). Of the distance between the side surface of the first signal wiring and the side surface of the second signal wiring facing each other in the first wiring group (for example, S1 shown in FIG. 4A). The second insulation of each center line of the first signal wiring of the second wiring group and the first signal wiring of the first wiring group facing each other through the second insulating layer. The same value as the distance in the plane direction of the layer (that is, the positional deviation amount of each wiring in the width direction), or the first signal wiring of the second wiring group and the first signal of the first wiring group It is preferable that the value is larger than the distance in the surface direction of the second insulating layer of each center line of the wiring.

  In the second wiring group, the distance between the side surface of the first signal wiring and the side surface of the second signal wiring facing each other (for example, S2 shown in FIG. 4A) is the above size. If there is, for example, even if the arrangement position of the second wiring group is displaced in the width direction of each wiring with respect to the position of the first wiring group, each wiring of the second wiring group Is within the width of each wiring of the first wiring group (that is, a wiring through which an electrical signal of the same phase is transmitted) opposed via the second insulating layer, and the first wiring group This is because it is difficult to be affected by the wiring through which the electrical signal having the opposite phase is transmitted.

  In the suspension substrate according to the present invention, the distance between the side surface of the first signal wiring and the side surface of the second signal wiring facing each other in the second wiring group, and the surface facing each other in the first wiring group. The value of ½ of the difference between the distance between the side surface of the first signal wiring and the side surface of the second signal wiring is the second wiring group facing through the second insulating layer. The same value as the distance in the surface direction of the second insulating layer of each center line of the first signal wiring and the first signal wiring of the first wiring group, or the first wiring of the second wiring group In order to make the value larger than the distance in the surface direction of the second insulating layer of each central line of the signal wiring and the first signal wiring of the first wiring group, for example, FIG. The side surfaces of the first signal wiring and the second signal facing each other in the second wiring group shown in FIG. A difference (S2) between a distance (S2) between the side surface of the wiring and a distance (S1) between the side surface of the first signal wiring and the side surface of the second signal wiring facing each other in the first wiring group. The half value of S1) may be designed so as to be the same value as the maximum positional deviation amount in the alignment when the second wiring group is formed. This is because the amount of positional deviation that actually occurs is in a range that is less than or equal to the maximum positional deviation amount.

In the present invention, the thickness of the first signal wiring and the second signal wiring in the second wiring group is set to be greater than the thickness of the first signal wiring and the second signal wiring in the first wiring group. It is also preferable to make it larger.
With the configuration as described above, the area of each wiring side surface facing each other in the second wiring group can be increased, and the first signal wirings facing each other in the second wiring group can be increased. This is because an increase in differential impedance caused by increasing the distance between the side surface and the side surface of the second signal wiring (S2 shown in FIG. 2A) can be suppressed.

  Note that a third insulating layer 16 may be formed on the second wiring group and the second insulating layer 14. This is because by covering the respective wirings 15a, 15b, 15c, and 15d constituting the second wiring group with the third insulating layer 16, it is possible to prevent deterioration of the wiring due to corrosion or the like. Moreover, it is because the capacity | capacitance of the capacitive coupling between each wiring can be enlarged more by filling the clearance gap between each wiring which comprises a 2nd wiring group with the 3rd insulating layer 16. FIG.

In the present invention, for example, as shown in FIG. 2A, the metal support substrate 11 has a region occupied by the first wiring group at a position overlapping the first wiring group in plan view. An opening 17 having an opening width larger than the width is preferably formed.
As described above, high-frequency signal transmission loss is increased by forming inductive or capacitive coupling between the wirings 13a, 13b, 13c, and 13d constituting the first wiring group and the metal support substrate 11 therebelow. This is to suppress this.
The above-mentioned “width of the region occupied by the first wiring group” is a length in a direction perpendicular to the longitudinal direction of the first wiring group. For example, in FIG. This indicates the length from the left end of the wiring 13a to the right end of the wiring 13d in the drawing.

The opening width of the opening 17 is smaller than the width of the area occupied by the wiring group (total number of wirings is 8) in which the first wiring group and the second wiring group are arranged in a plane. The width is preferable.
For example, in the configuration in which the first wiring group and the second wiring group are arranged in a plane (the total number of wirings is 8), the width of the opening provided in the metal support substrate is also large in transmission loss of high-frequency signals. In order to suppress this, it is necessary to make the width larger than the width of the region occupied by the wiring group (total number of wirings is 8) in which the first wiring group and the second wiring group are arranged in a plane. .
On the other hand, in the present invention, as described above, since the second wiring group is laminated on the first wiring group via the second insulating layer 14, the opening provided in the metal support substrate 11 is provided. The portion 17 only needs to have an opening width larger than the width of the region occupied by the first wiring group, and this opening width is planarly divided between the first wiring group and the second wiring group. The first wiring group and the second wiring group are arranged in a plane (wiring) by setting the opening width to be smaller than the width of the region occupied by the arranged wiring group (total number of wirings is 8). This is because the physical strength of the suspension substrate can be increased more than the total number of eight).

  Although not shown in order to avoid complication, a seed layer for electrolytic plating formation of the wiring is provided between the wirings 15a, 15b, 15c, 15d and the second insulating layer 14. It may be done. Similarly, a seed layer for electrolytic plating of the wiring may be provided between the wirings 13a, 13b, 13c, 13d and the first insulating layer 12.

  In the present invention, the number of wirings constituting the first wiring group and the number of wirings constituting the second wiring group are not limited to four, but may be more than four. good. However, the arrangement relationship in the thickness direction of each wiring constituting each wiring group is such that wirings that transmit electric signals of the same phase face each other with the second insulating layer interposed therebetween.

  For example, in the case where the number of wirings constituting the first wiring group and the second wiring group is 6 respectively, the wiring is formed on the first insulating layer 12 as shown in FIG. A first wiring group having six wirings (23a, 23b, 23c, 23d, 23e, 23f) is formed, and a second insulating layer is formed on the first wiring group and the first insulating layer 12. 14 is formed, and a second wiring group having six wirings (25a, 25b, 25c, 25d, 25e, 25f) is formed on the second insulating layer.

  And about the arrangement | positioning relationship of each wiring, the said 1st signal wiring (for example, 23a, 23c, 23e) of the said 1st wiring group and the 1st signal wiring (for example, 25a, 25c) of the said 2nd wiring group are used. 25e) through the second insulating layer 14, the second signal wiring (for example, 23b, 23d, 23f) of the first wiring group and the second signal of the second wiring group. Wirings (for example, 25b, 25d, and 25f) are disposed so as to face each other with the second insulating layer 14 therebetween.

  Further, also in the present embodiment, each center line (for example, FIG. 3B) of the first signal wiring (for example, 25a) and the second signal wiring (for example, 25b) adjacent to each other in the second wiring group is shown. The distance (P12) between C25a and C25b) is the distance between the center lines of the first signal wiring (for example, 23a) and the second signal wiring (for example, 23b) that are adjacent to each other in the first wiring group. The distance (S12) between the side surface of the first signal wiring (for example, 25a) and the side surface of the second signal wiring (for example, 25b) that are equal to (P11) and face each other in the second wiring group is In the first wiring group, the distance is larger than the distance (S11) between the side surface of the first signal wiring (for example, 23a) and the side surface of the second signal wiring (for example, 23b) facing each other, and the second wiring Formed to be smaller than the first signal lines adjacent to each other (e.g., 25a) and said second signal wiring distance between each center line (for example 25b) (P12) in the lines.

Next, the circuit configuration of the interleave wiring of the suspension board according to the present invention will be described. In order to avoid complication, only the circuit configuration in the case where the number of wirings constituting the first wiring group and the second wiring group is six will be described here.
FIG. 6 is an explanatory diagram showing a circuit configuration of interleave wiring of the suspension board 20 shown in FIG. In FIG. 6, in the drawing, the alternately arranged wiring group located on the left side shows the first wiring group, and the alternately arranged wiring group located on the right side shows the second wiring group.
As shown in FIG. 6, the interleaved wiring structure 30 in the suspension board 20 includes a first signal wiring that electrically connects the connection terminal 31a and the connection terminal 31c, and an electrical connection between the connection terminal 31b and the connection terminal 31d. It consists of a pair of differential wiring composed of second signal wiring.

Here, since the conventional interleaved wiring structure is a single-layer structure, in the present invention, it is a laminated structure. Therefore, each differential wiring is first connected to the upper and lower wiring groups via the interlayer connection via. (I.e., the first and second wiring groups).
For example, as shown in FIG. 6, the electrical signal (first electrical signal) from the connection terminal 31a is not only transmitted to the first wiring group, but also via the interlayer connection line 36a in the interlayer connection via 35a. Then, it is also transmitted to the second wiring group. Then, the electrical signal (first electrical signal) from the connection terminal 31a transmitted to the second wiring group is transmitted to the connection terminal 31c via the interlayer connection line 36c in the interlayer connection via 35c.
Similarly, the electrical signal (second electrical signal) from the connection terminal 31b is not only transmitted to the first wiring group, but also via the interlayer connection line 36b in the interlayer connection via 35b. It is also transmitted to the wiring group. Then, the electrical signal (second electrical signal) transmitted from the connection terminal 31b to the second wiring group is transmitted to the connection terminal 31d via the interlayer connection line 36d in the interlayer connection via 35d.

Next, the circuit configuration of the upper and lower wiring groups (that is, the first and second wiring groups) will be described.
As shown in FIG. 6, in the first wiring group (the wiring group on the left side in the drawing), the first signal wiring branches into wirings 23a, 23c, and 23e at a branch point 32a, and similarly, the second signal The wiring branches to the wirings 23b, 23d, and 23f at the branch point 32b, and the branched wirings are adjacent to the wirings through which electric signals having opposite phases are transmitted from the left end of the drawing, such as 23a, 23b, 23c, 23d, 23e, and 23f are arranged in parallel in this order.
Then, the wirings 23a, 23c, and 23e through which electrical signals of the same phase are transmitted are connected by the connection line 34a via the connection vias 33a, 33b, and 33c, respectively, and similarly, the wirings 23b, 23d, and 23f are connected. Are connected by a connection line 34b via connection vias 33d, 33e, 33f.

  In the present embodiment, for example, the connection vias 33a, 33b, and 33c, and the connection vias 33d, 33e, and 33f are formed in the first insulating layer 12, and the connection line 34a and the connection line 34b are metal-supported. It can be configured to be formed in the opening 17 of the substrate 11. In addition, said structure is an illustration, Comprising: It will not specifically limit if electrically connected equally.

Next, the second wiring group (the wiring group on the right side in the drawing) will be described. The first signal wiring branches into wirings 25a, 25c, and 25e at a branch point 32c. Similarly, the second signal wiring is , 25a, 25b, 25c, 25d, 25b, 25c, 25d from the left end of the drawing so that the branching lines 32b, 25d, 25f branch to the wirings 25b, 25d, 25f. They are arranged in parallel in the order of 25e and 25f.
Then, the wirings 25a, 25c, and 25e through which the electrical signals of the same phase are transmitted are connected by the connection line 34c via the connection vias 33g, 33h, and 33i, respectively. Similarly, the wirings 25b, 25d, and 25f are connected. Are connected by a connection line 34d via connection vias 33j, 33k, 33l.

  In the present embodiment, for example, the connection vias 33g, 33h, 33i and the connection vias 33j, 33k, 33l are formed in the third insulating layer 16, and the connection line 34c and the connection line 34d are 3 insulating layers 16 may be formed. In addition, said structure is an illustration, Comprising: It will not specifically limit if electrically connected equally.

  Next, each member constituting the suspension substrate of the present invention will be described.

[Metal support substrate]
The material of the metal support substrate 11 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 can be used.
For example, the thickness of the metal support substrate 11 is preferably in the range of 10 μm to 30 μm, and more preferably in the range of 15 μm to 25 μm.

[First insulating layer]
The first insulating layer 12 is formed on the surface of the metal supporting substrate 11, and each wiring of the first wiring group formed on the first insulating layer 12 and the metal supporting substrate 11 are connected to each other. It is electrically insulated.
The material of the first insulating layer 12 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 12 may be a photosensitive material or a non-photosensitive material. The thickness of the 1st insulating layer 12 exists in the range of 5 micrometers-30 micrometers, for example.

[wiring]
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.

[Second insulating layer]
The second insulating layer 14 is formed on the first wiring group and the first insulating layer 12, and each wiring that constitutes the first wiring group and each of the second wiring group. It electrically insulates the wiring. In addition, by filling the gaps between the wirings constituting the first wiring group with the second insulating layer 14, the capacity of capacitive coupling between the wirings can be further increased.
The material of the second insulating layer 14 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 14 may be a photosensitive material or a non-photosensitive material.
The thickness of the second insulating layer 14 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.

[Third insulating layer]
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 the third insulating layer 16. In addition, by filling the gaps between the wirings constituting the second wiring group with the third insulating layer 16, it is possible to further increase the capacity of capacitive coupling between the wirings.
Examples of the material of the third insulating layer 16 include polyimide. The material of the third insulating layer 16 may be a photosensitive material or a non-photosensitive material.
The thickness of the third insulating layer 16 is, for example, in the range of 4 μm to 30 μm on each wiring configuring the second wiring group.

[Method of manufacturing suspension substrate]
Next, the manufacturing method of the suspension substrate of the present invention will be described. In order to avoid complication, here, a case will be described in which the number of wirings constituting each of the first wiring group and the second wiring group is six. In addition, the manufacturing method of the suspension substrate of the present invention is not particularly limited as long as it is a method capable of obtaining the suspension substrate having the above-described configuration.

FIG. 7 is a schematic process diagram showing an example of a method for manufacturing a suspension substrate according to the present invention.
In order to manufacture the suspension substrate 20 according to the present invention, for example, as shown in FIG. 7A, the first insulating layer 12 and the conductive layer 13A are sequentially laminated on the metal supporting substrate material 11A. A laminated body is prepared, and the conductive layers 13A are processed by a conventionally known method such as photoengraving using a dry film resist and etching, and the wirings 23a, 23b, 23c, 23d, 23e constituting the first wiring group, 23f is formed (FIG. 7B).
Next, a second insulating layer 14 is formed on the first wiring group and the first insulating layer 12 (FIG. 7C), and photoengraving and electroplating using a dry film resist are performed. The wirings 25a, 25b, 25c, 25d, 25e, and 25f constituting the second wiring group are formed on the second insulating layer 14 by a conventionally known method such as (FIG. 7D).
Next, a third insulating layer 16 is formed on the second wiring group and the second insulating layer 14 (FIG. 7E). Finally, the metal supporting board material 11A is etched, A metal support substrate 11 having an opening 17 is formed under the first wiring group to obtain a suspension substrate 20 according to the present invention (FIG. 7F).

Although not shown in order to avoid complication, in the present invention, for example, the interlayer connection vias 35a, 35b, 35c, 35d and the interlayer connection lines 36a, 36b, 36c, 36d shown in FIG. Can be formed in the second insulating layer 14.
Here, the interlayer connection vias 35a, 35b, 35c, and 35d may be integrally formed with the interlayer connection lines 36a, 36b, 36c, and 36d, respectively.

  Similarly, although not shown, in the present invention, for example, the connection vias 33a, 33b, 33c and the connection vias 33d, 33e, 33f shown in FIG. 6 are formed in the first insulating layer 12. The connection line 34 a and the connection line 34 b can be formed in the opening 17 of the metal support substrate 11.

  Similarly, for example, the connection vias 33g, 33h, 33i and the connection vias 33j, 33k, 33l shown in FIG. 6 are formed in the third insulating layer 16, and the connection line 34c and the connection line 34d are formed. It can be formed on the third insulating layer 16.

[suspension]
Next, the suspension of the present invention will be described. A suspension according to the present invention includes the above-described suspension substrate and a load beam.

  FIG. 8 is a schematic plan view showing an example of a suspension according to the present invention. A suspension 50 shown in FIG. 8 includes the suspension substrate 1 described above, a load beam 51 provided on the back surface side (metal support substrate 11 side) of the suspension substrate 1, and a base plate (not shown). It is. The load beam and the base plate can be the same as the load beam and base plate used for a general suspension.

  In the present invention, by using the above-described suspension substrate, it is possible to obtain a highly reliable suspension in which the bandwidth of a high-frequency signal is stably maintained while having a low impedance.

[Suspension with head]
Next, the head suspension according to the present invention will be described. The suspension with a head of the present invention includes the above-described suspension and a magnetic head slider mounted on the suspension.

  FIG. 9 is a schematic plan view showing an example of a suspension with a head according to the present invention. A suspension 60 with a head shown in FIG. 9 has the above-described suspension 50 and a magnetic head slider 61 mounted on the tongue 2 of the suspension 50.

  Since the suspension 50 is the same as described above, the description thereof is omitted here. The magnetic head slider 61 can be the same as the magnetic head slider used in a general suspension with a head.

  According to the present invention, by using the above-described suspension substrate, it is possible to provide a highly reliable suspension with a head that has a low impedance and stably holds a high-frequency signal bandwidth.

[Hard disk drive]
Next, the hard disk drive of the present invention will be described. The hard disk drive of the present invention includes the above-described suspension with a head.

FIG. 10 is a schematic perspective view showing an example of a hard disk drive according to the present invention.
A hard disk drive 70 shown in FIG. 10 has a case 71, a disk 72 that is rotatably attached to the case 71 and stores data, a spindle motor 73 that rotates the disk 72, and a desired flying on the disk 72. It has a suspension 60 with a head that is provided so as to be close to each other while maintaining a height and that includes a slider for writing and reading data to and from the disk 72. Of these, the suspension 60 with a head is movably attached to the case 71, and a voice coil motor 74 that moves the slider of the suspension 60 with a head along the disk 72 is attached to the case 71. The head suspension 60 is attached to the voice coil motor 74 via an arm 75.

  Note that the suspension with a head is the same as that described above, so description thereof is omitted here. As other members, the same members as those used in a general hard disk drive can be used.

  According to the present invention, by using the above-described suspension with a head, it is possible to obtain a hard disk drive with higher functionality and higher reliability.

  The suspension substrate, suspension, suspension with head, and hard disk drive according to the present invention have been described above, but the present invention is not limited to the above-described 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.

As shown in FIG. 16A, in the second wiring group (wirings 25a to 25f), the distance (S12) between the side surface of the first signal wiring and the side surface of the second signal wiring that face each other is In the first wiring group (wirings 23a to 23f), the suspension substrate 20a according to the present invention is larger than the distance (S11) between the side surface of the first signal wiring and the side surface of the second signal wiring facing each other. As shown in FIG. 17A, in the second wiring group (wirings 525a to 525f), there is a distance (S22) between the side surface of the first signal wiring and the side surface of the second signal wiring that face each other. In the first wiring group (wirings 523a to 523f), the suspension substrate 500a having the same distance (S21) between the side surface of the first signal wiring and the side surface of the second signal wiring that face each other. When the second wiring group is not displaced with respect to the first wiring group under the condition that the differential impedance is set to 20Ω and the wiring regions are substantially the same (FIG. 16A, FIG. When the positional deviation of a)) and 5 μm occurred (FIG. 16B, FIG. 17B), a −3 dB bandwidth at a wiring length of 40 mm was calculated by simulation.
In both Example 1 and Comparative Example 1, 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
With respect to the suspension substrate 20a (position shift amount 0 μm) according to the present invention having the configuration shown in FIG. 16 (a) and the suspension substrate 20b (position shift amount 5 μm) according to the present invention having the configuration shown in FIG. 16 (b), Differential impedance and -3 dB bandwidth were calculated respectively.
Note that the suspension board 20b shown in FIG. 16B has the wirings (25a, 25b, 25c, 25d, 25e, 25f) of the second wiring group in the suspension board 20a shown in FIG. While maintaining the mutual distance, the arrangement position is the width direction of each wiring (right direction in the drawing) with respect to the arrangement position of each wiring (23a, 23b, 23c, 23d, 23e, 23f) of the first wiring group. ) Is equivalent to a state in which a positional deviation (deviation amount OS11 = 5 μm) occurs.
<Simulation conditions>
First wiring group (wirings 23a to 23f):
In each case, the thickness is 5 μm, the width (W11) is 28 μm, and the distance between each wiring (S11) is 12 μm.
Second wiring group (wirings 25a to 25f):
In each case, the thickness is 5 μm, the width (W12) is 18 μm, and the distance between each wiring (S12) is 22 μm.
Second insulating layer 14: thickness on wiring (D11) 5 μm
Third insulating layer 16: thickness on wiring (D12) 5 μm
Distance between the opening end of the metal support substrate 11 and the first wiring group:
Both interval (LS1a) and interval (LS1b) are 25 μm.
<Simulation results>
Misalignment amount 0 μm: Differential impedance 19.8Ω, Bandwidth 6.2 GHz
Position deviation 5 μm: differential impedance 19.3Ω, bandwidth 6.2 GHz

(Comparative Example 1)
With respect to the suspension board 500a (position shift amount 0 μm) configured as shown in FIG. 17A and the suspension board 500b (position shift amount 5 μm) configured as shown in FIG. The width was calculated.
Note that the suspension substrate 500b shown in FIG. 17B has the wirings (525a, 525b, 525c, 525d, 525e, 525f) of the second wiring group in the suspension substrate 500a shown in FIG. While maintaining the mutual distance, the arrangement position is the width direction of each wiring (right direction in the drawing) with respect to the arrangement position of each wiring (523a, 523b, 523c, 523d, 523e, 523f) of the first wiring group. ) Is equivalent to a state in which a positional deviation (deviation amount OS12 = 5 μm) occurs.
<Simulation conditions>
First wiring group (wirings 523a to 523f):
In each case, the thickness is 5 μm, the width (W21) is 25 μm, and the distance between each wiring (S21) is 15 μm.
Second wiring group (wirings 525a to 525f):
In any case, the thickness is 5 μm, the width (W22) is 25 μm, and the distance between each wiring (S22) is 15 μm.
Second insulating layer 514: thickness on wiring (D21) 5 μm
Third insulating layer 516: thickness on wiring (D22) 5 μm
Distance between the opening end of the metal support substrate 11 and the first wiring group:
Both interval (LS2a) and interval (LS2b) are 25 μm
<Simulation results>
Misalignment amount 0μm: Differential impedance 19.7Ω, Bandwidth 7.2GHz
Position deviation 5 μm: Differential impedance 18.2Ω, Bandwidth 5.9 GHz

The results will be described.
As shown in Comparative Example 1, in the second wiring group (wirings 525a to 525f), the distance (S22) between the side surface of the first signal wiring and the side surface of the second signal wiring that face each other is first. In the suspension substrate having the same distance (S21) between the side surface of the first signal wiring and the side surface of the second signal wiring facing each other in the wiring group (wirings 523a to 523f), the positional deviation amount is 0 μm ( That is, in the case of no displacement, the bandwidth value was 7.2 GHz. However, in the case of the displacement amount of 5 μm, the bandwidth value was narrowed to 5.9 GHz. The value of the differential impedance also varied from 19.7Ω to 18.2Ω in a direction away from the target differential impedance value (20Ω).

  On the other hand, as shown in the first embodiment, in the suspension substrate according to the present invention, the bandwidth value is either when the displacement amount is 0 μm (that is, when there is no displacement) or when the displacement amount is 5 μm. The result was superior to that of Comparative Example 1 for the purpose of stably maintaining the bandwidth of the high-frequency signal. The fluctuation of the differential impedance value was also in the range of 19.8Ω to 19.3Ω, which was a stable result with respect to the target differential impedance value (20Ω).

DESCRIPTION OF SYMBOLS 1, 10, 20, 20a, 20b ... Suspension board 2 ... Tongue part 3 ... Connection terminal part 4, 5 ... Wiring group 11 ... Metal support board 11A ... Metal support base Plate material 12 ... 1st insulating layer 13A ... Conductive layer 13a, 13b, 13c, 13d ... Wiring 14 ... 2nd insulating layer 15a, 15b, 15c, 15d ... Wiring 16 ... Third insulating layer 17: Opening 23a, 23b, 23c, 23d, 23e, 23f ... Wiring 25a, 25b, 25c, 25d, 25e, 25f ... Wiring 30 ... Interleaved wiring structure 31a , 31b, 31c, 31d ... connection terminals 32a, 32b, 32c, 32d ... branching points 33a, 33b, 33c, 33d, 33e, 33f ... connection vias 33g, 33h, 33i, 33 j, 33k, 33l ... connection vias 34a, 34b, 34c, 34d ... connection lines 35a, 35b, 35c, 35d ... interlayer connection vias 36a, 36b, 36c, 36d ... interlayer connection lines 50. ..Suspension 51 ... Load beam 60 ... Suspension with head 61 ... Magnetic head slider 70 ... Hard disk drive 71 ... Case 72 ... Disk 73 ... Spindle motor 74 ... Voice Coil motor 75 ... Arms 110, 120 ... Suspension substrate 111, 111A ... Metal support substrate 112 ... First insulating layer 113a, 113b, 113c, 113d ... Wiring 114 ... First 2 insulating layers 117... Opening 130... Interleaved wiring structure 131 a, 131 b, 31c, 131d ... connection terminal 132a, 132b ... branch point 133a, 133b, 133c, 133d ... connection via 134a, 134b ... connection line 200 ... laminated wiring structure 212 ... first Insulating layers 213a, 213b ... Wiring 214 ... Second insulating layer 216 ... Third insulating layer 300 ... Multilayer wiring structure 312 ... First insulating layer 313a, 313b, 313c, 313d ... Wiring 314 ... Second insulating layer 315a, 315b, 315c, 315d ... Wiring 316 ... Third insulating layer 400b ... Suspension substrate 411 ... Metal support substrate 412 ... First insulating layer 413a, 413b, 413c, 413d ... wiring 414 ... second insulating layer 415a, 415b, 415c, 415d ..Wiring 416 ... third insulating layer 423a, 423b, 423c, 423d, 423e, 423f ... wiring 425a, 425b, 425c, 425d, 425e, 425f ... wiring 500a, 500b ... for suspension Substrate 511... Metal support substrate 512... First insulating layer 513 a, 513 b, 513 c, 513 d .. Wiring 514... Second insulating layer 515 a, 515 b, 515 c, 515 d. ..Third insulating layer 523a, 523b, 523c, 523d, 523e, 523f ... wiring 525a, 525b, 525c, 525d, 525e, 525f ... wiring

Claims (8)

A metal support substrate;
A first insulating layer formed on the metal support substrate;
A first wiring group formed on the first insulating layer;
A second insulating layer formed on the first wiring group and the first insulating layer;
A second wiring group formed on the second insulating layer;
A suspension substrate comprising:
In the first wiring group and the second wiring group, a plurality of first signal wirings electrically connected to each other and the first signal wirings are electrically independent and electrically connected to each other. A plurality of second signal wirings are respectively arranged in a plane and alternately arranged,
The first signal wiring of the first wiring group and the first signal wiring of the second wiring group are opposed to each other via the second insulating layer, and the second signal of the first wiring group is The first wiring group and the second wiring group are arranged so that a wiring and the second signal wiring of the second wiring group are opposed to each other through the second insulating layer,
The distance between the first signal wiring adjacent to each other in the second wiring group and the center line of the second signal wiring is the same as the distance between the first signal wiring adjacent to each other in the first wiring group and the second signal wiring. Equal to the distance between each center line of the signal wiring,
The distance between the side surface of the first signal wiring and the side surface of the second signal wiring facing each other in the second wiring group is the same as the distance between the side surface of the first signal wiring facing each other in the first wiring group. It is larger than the distance between the side surfaces of the second signal wirings and smaller than the distance between the first signal wirings adjacent to each other in the second wiring group and the center lines of the second signal wirings. Suspension substrate characterized by the above. A distance between a side surface of the first signal wiring and the side surface of the second signal wiring facing each other in the second wiring group; a side surface of the first signal wiring facing each other in the first wiring group; The value of ½ of the difference between the distance from the side surface of the second signal wiring is
Surface direction of the second insulating layer of each center line of the first signal wiring of the second wiring group and the first signal wiring of the first wiring group facing each other through the second insulating layer Or the same value as
Alternatively, the value is larger than the distance in the surface direction of the second insulating layer between the center lines of the first signal wiring of the second wiring group and the first signal wiring of the first wiring group. The suspension substrate according to claim 1.   A thickness of the first signal wiring and the second signal wiring in the second wiring group is larger than a thickness of the first signal wiring and the second signal wiring in the first wiring group. The suspension substrate according to claim 1 or 2.   The metal support substrate is formed with an opening having an opening width larger than a width of a region occupied by the first wiring group at a position overlapping the first wiring group in plan view. The suspension substrate according to any one of claims 1 to 3.   The suspension substrate according to any one of claims 1 to 4, wherein a third insulating layer is formed on the second wiring group and the second insulating layer.   A suspension comprising the suspension substrate according to any one of claims 1 to 5 and a load beam.   A suspension with a head comprising the suspension according to claim 6 and a magnetic head slider mounted on the suspension. A hard disk drive comprising the suspension with a head according to claim 7.

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