JP2002170215A - Magnetic recording head gimbals assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording HGA having a structure capable of reducing parasitic capacitance as much as possible. SOLUTION: This magnetic recording HGA is provided with a magnetic head slider 131, a metallic suspension (composed of a metallic load beam 132 and a metallic gimbals 130 disposed thereon) for supporting the slider 131, and magnetic head lead patterns 134a and 134d formed through insulating films 140 and 141 on the suspension. The insulating films 140 and 141 disposed on the gimbals 130 only above a through-hole 138 formed by partially penetrating the gimbals 130 below the patterns 134a to 134d support the patterns 134a to 134d (the insulating films 140 and 141 intersect the patterns 134a to 134d only above the through-hole 138).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording head gimbal assembly (hereinafter referred to as "HGA") mainly applied to a magnetic disk device or a magneto-optical disk device and having a structure capable of reducing parasitic capacitance.

[0002]

2. Description of the Related Art Conventionally, as a well-known technique related to this type of HGA for magnetic recording, for example, Japanese Unexamined Patent Publication No. 9-282624
And a hard disk drive device including the same. In this HGA, a through-hole is provided on a metal suspension to reduce a parasitic capacitance generated between the conductive lead pattern on the suspension and the suspension. The specific configuration will be described with reference to the drawings. A metal gimbal (here, called a flexure) 930 is mounted on a metal load beam 932.
In addition, a metal base plate 933 is adhered by laser welding or the like, and a slider 931 for a magnetic head and a total of four recording / recording lines including two recording lines and two reproduction lines are provided on the gimbal 930. A read pattern (for a magnetic head) 934a to 934d and four electrodes 935a to 935d connected to the respective lead patterns 934a to 934d are provided.

A base plate 933 is mounted on one end of the gimbal 930, and a slider 93 is mounted on the other end of the gimbal 930 opposite to the base plate 933.
1 is attached. Lead pattern 934a-9
34d are formed on the gimbal 930 via an insulating layer by etching, and electrodes 935a to 935d are connected to one end of each of them, respectively.
The other end opposite to 35a to 935d is electrically connected to a magnetic head through a slider 931. Lead patterns 934a to 934 on gimbal 930
A plurality of through holes 938 are formed directly below 4d,
The electrodes 935a to 935d formed on the gimbal 930 on the side opposite to the slider 931 are made of a flexible circuit board (FPC / Fle
It is provided for electrically connecting the X-ray printed circuit and the lead patterns 934a to 934d by soldering or the like.

FIG. 11 is a side view of the HGA viewed from the lateral direction. Referring to FIG.
After the gimbal 930 and the base plate 933 are mounted thereon, the slider 931 and the lead patterns 934a to 934 are connected to the gimbal 930 so as to be connected thereto.
It can be seen that d is arranged.

[0005] In this HGA, the gimbal 930 or both the gimbal 930 and the load beam 932 have through holes 93.
8 are provided, and the technical effects of such a through hole 938 will be described below.

FIG. 12 is an enlarged perspective view of the vicinity of the through hole 938 of the gimbal 930 of the HGA shown in FIG. Here, in FIG.
Lead pattern 9 shown as four installed above
34a to 934d are three-layered wiring patterns 951a, 952a,
953a, 951b, 952b, 953b, 951c,
952c, 953c, 951d, 952d, and 953d.

FIG. 13 is a side sectional view showing a detailed structure of a conventional HGA having no through-hole in a direction along one lead pattern. This H
In the GA, a gimbal 864 is provided on the load beam 865, and an insulating film 861, a lead pattern 862, and an insulating film 863 are stacked on the gimbal 864 in this order.

FIG. 14 is a side sectional view showing a detailed structure of the HGA in FIG. 12 in a direction along one lead pattern. In this HGA, a through-hole 966 is formed around the gimbal 964 by providing a gimbal 964 formed at equal intervals by partially removing the through-hole at a predetermined interval on the load beam 965. It is shown that an insulating film 961, a lead pattern 962, and an insulating film 963 are further provided on these gimbals 964 in this order.

When these HGAs are compared, the HGA provided with the through-hole 966 is compared with the HGA without the through-hole,
The lead pattern 9 is formed at the portion where the through hole 966 is provided.
Since the distance from the lower surface of 62 to the metal plate facing the lead pattern 962 increases from the thickness of the insulating film 963 to the sum of the thickness of the insulating film 963 and the thickness of the gimbal 966, the lead pattern 962 and the gimbal 964 or The parasitic capacitance between the load beam 965 and the load beam
The parasitic capacitance between the lead pattern 862 of A and the gimbal 864 is reduced, and the resonance point at the data transfer frequency shifts to a higher frequency. As a result, the effect that the transferable frequency bandwidth is expanded is obtained.

Further, in the HGA disclosed in Japanese Patent Application Laid-Open No. 9-282624 and a hard disk drive having the HGA, an HGA having another structure having a through hole is provided.
A is also disclosed.

FIG. 15 is a side sectional view showing a detailed structure of another HGA having a conventional through-hole 976 in a direction along one lead pattern 972. This HGA
Then, by partially removing the penetration at a predetermined interval, the penetration is partially removed on the load beam 975 formed at equal intervals so as to have an interval larger than the interval of the load beam 975. By providing the gimbals 974 at equal intervals, a through-hole 976 is formed around the load beam 975 and the gimbal 974, and further, an insulating film 971 is provided on these gimbals 974.
This shows a state in which a lead pattern 972 and an insulating film 973 are provided by being stacked in this order. With such a structure, the parasitic capacitance generated between the lead pattern 962 and the load beam 965 in the structure shown in FIG.
Since the portion 75 is eliminated from the removed portion, the parasitic capacitance of the entire HGA can be reduced.

FIG. 16 is a side sectional view showing a detailed structure of another HGA having a conventional through hole 986 in a direction along one lead pattern 982. This HGA
In this configuration, a gimbal 984 composed of a convex-concave body having a step formed between equally-spaced convex portions on the load beam 985 and a concave portion formed integrally is provided, so that the gimbal 984 has a concave portion around the concave portion. It is assumed that a void 986 is formed, and further, an insulating film 981, a lead pattern 982, and an insulating film 983 are stacked and provided in this order on the projections of these gimbals 984. If the gimbal 984 has a structure in which the gap 986 is secured by devising the shape of the gimbal 984, the distance between the lead pattern 982 and the concave portion of the gimbal 984 in the gap 986 is smaller than that of the conventional HGA. The space which is enlarged and formed in the concave portion has a relative dielectric constant of an insulating layer (insulating films 981, 9).
83) Since it is smaller, the parasitic capacitance of the entire HGA can be reduced.

As another known technique related to the HGA, there is, for example, a floating magnetic head assembly disclosed in Japanese Patent Application Laid-Open No. 5-36049.

[0014]

In the case of the above-described HGA having the through hole, for example, if the HGA has the cross-sectional structure shown in FIG. 14, the lead is provided in the portion where the gimbal 964 still exists after the through hole 966 is provided. Pattern 962
There is a problem that the parasitic capacitance before the improvement exists between the gimbal 964 and the gimbal 964. Therefore, the parasitic capacitance can be reduced by reducing the length of the gimbal 964 formed in a rectangular shape in the cross-sectional direction, but it is difficult to maintain the rigidity of the gimbal 964 by reducing the length. The length cannot be significantly reduced. Therefore, in the case of the HGA having this cross-sectional structure, there is a limit to the amount of reduction in the parasitic capacitance.

On the other hand, the data transfer rate of recording / reproducing signals applied to recent magnetic disk devices and the like is required to be further increased, and the upper limit of the data transfer rate is determined by various factors. Then, the upper limit of the data transfer rate is determined by the read pattern on the suspension and the resonance frequency of the recording circuit or the reproducing circuit composed of the head. If the data transfer rate increases to the resonance frequency, an excessive current flows through the recording circuit or the reproducing circuit on the suspension at this time. When an excessive current flows through the reproducing circuit, the reproducing head M
If the R element is destroyed, the reproducing operation becomes impossible. If an excessive current flows through the recording circuit, an induced current is generated in an adjacent reproducing circuit, and the MR element is destroyed by the induced current. To increase the rate,
It is necessary to increase the resonance frequency.

The resonance frequency f ₀ is f ₀ = 1 / ｛2π (L
C) It is given by equation (1) having a relationship of ^{1/2 1/2} . Here, L is the inductance of the circuit portion including the read pattern of the recording circuit or the reproduction circuit and the head, and C is the capacitance of the same circuit portion. The capacitance C is
Since the parasitic capacitance (strictly speaking, the capacitance of the lead pattern and the ground) generated between the lead pattern and the gimbal or the load beam is dominant, it is necessary to reduce the parasitic capacitance of the suspension to transfer data such as a magnetic disk device. This is one of the major challenges in raising rates.

The present invention has been made in order to solve such problems, and a technical problem thereof is to provide a magnetic recording HGA having a structure capable of minimizing parasitic capacitance as much as possible.

[0018]

According to the present invention, a slider for a magnetic head, a metal suspension supporting the slider, and a lead pattern for the magnetic head supported on the suspension via an insulator are provided. In the magnetic recording HGA having the above, the suspension is partially removed at equal intervals, and the magnetic recording HGA in which the insulator supports the lead pattern only at the position above the removed portion of the suspension is obtained.

Further, according to the present invention, the HG for magnetic recording
In A, the HGA for magnetic recording provided through the portion where the suspension is removed is obtained.

Further, according to the present invention, the magnetic recording H
In GA, the suspension consists of a metal gimbal placed on a metal load beam.
A through hole is formed by being partially penetrated and removed at equal intervals, and a magnetic recording HGA that supports a lead pattern only at a position above the through hole of the gimbal can be obtained as an insulator.

In addition, according to the present invention, in the above-mentioned HGA for magnetic recording, the load beam is partially penetrated and removed at equal intervals equal to or less than the gimbal interval to form a through hole. An HGA for magnetic recording that supports the lead pattern only at a position above the through hole of the gimbal connected to the through hole of the load beam is obtained.

On the other hand, according to the present invention, there is provided a magnetic recording comprising a slider for a magnetic head, a metal suspension supporting the slider, and a lead pattern for the magnetic head supported on the suspension via an insulator. HGA for
, The suspension comprises a convex-concave body in which a concave portion is integrally formed by forming a step between convex portions having equal intervals, and the insulator is a magnetic member for supporting the lead pattern only at a position above the concave portion of the suspension. An HGA for recording is obtained.

On the other hand, according to the present invention, the magnetic recording H
In GA, the suspension consists of a metal gimbal placed on a metal load beam.
An HGA for magnetic recording, which supports a lead pattern only at a position above the recess of the gimbal, is obtained by forming an uneven body in which a recess is integrally formed by forming a step between projections having equal intervals. Can be

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a plan view showing the basic configuration of an HGA for magnetic recording according to one embodiment of the present invention. This HGA
In the case of, the metal gimbal 130 and the metal base plate 133 forming the suspension are bonded on the metal load beam 132 by laser welding or the like in the basic configuration, similarly to the conventional one shown in FIG. On the gimbal 130, a slider 131 for the magnetic head and a total of four read / write (for the magnetic head) read / write patterns 134 composed of two recording wires and two reproducing wires.
a to 134d and their respective lead patterns 134a to 134d.
134d connected to four electrodes 135a-1
35d is common, but here, the gimbal 130 located below the lead patterns 134a to 134d is partially penetrated and removed, and the through hole 138 formed by the removed portion of the gimbal 130 is provided. Film 14 placed on gimbal 130 only above
0, 141 support the lead patterns 134a to 134d, so that the insulating films 140, 141
Only on the surface 38, the structure intersects with the lead patterns 134a to 134d.

The HGA also has the same basic structure as the conventional one shown in FIG. That is, the base plate 133 is provided at one end of the gimbal 130.
Is mounted, and a slider 131 is mounted on the other end side opposite to the base plate 133.
The lead patterns 134a to 134d are formed on the gimbal 130 via the insulating films 140 and 141 by etching.
a to 135d are connected, and each of the electrodes 135a to 135d
The other end opposite to 35d is electrically connected to the magnetic head through the slider 131. Immediately below the lead patterns 134a to 134d on the gimbal 130, a plurality of through holes 138 are formed.
Electrode 1 formed on the side opposite to slider 131 on 30
35a to 135d are flexible circuit boards (FPC / Flexible) formed by a combination of those having the same polarity.
Printed Circuit) and Lead Pattern 1
34a to 134d are provided for electrical connection by soldering or the like.

Incidentally, the insulating film 140 here is bridged every other through-hole 138 on the through-hole 138 to support each of the lead patterns 134a to 134d. Is bridged on the through hole 138 for each through hole 138 (hereinafter, this structure is referred to as Configuration 1
). In any case, the area where the insulating film 140 and the through hole 138 overlap with each other in the configuration of the HGA shown in FIG. As a result, in the case of the HGA shown in FIG. 1, the length of the insulating film 140 is smaller than the length of the through hole 138 in the extending direction (the vertical direction in FIG. 1) of each of the lead patterns 134a to 134d. However, the length of the through-hole 138 and the length of the insulating film 140 may be the same. That is, an important configuration of the HGA of the present invention is that the insulating film 140 and each of the lead patterns 134a to 134d intersect only directly above the through-hole 138. Is slightly changed, the effect of reducing the parasitic capacitance hardly changes.

In the HGA shown in FIG.
41 is provided in the vicinity of the electrodes 135a to 135d, but also in the vicinity of these electrodes 135a to 135d, via the insulating film 141, the respective lead patterns 134a to 134d.
The insulating film 141, the lead patterns 134a to 134d, and the electrodes 135a to 135d such that the electrodes d or 135a to 135d intersect only directly above the through holes 138.
It is important to determine the mutual positions of d and the through hole 138. In particular, since the areas of the electrodes 135a to 135d are large enough to be equal to the entire area of each of the lead patterns 134a to 134d, if the electrodes 135a to 135d have a parasitic capacitance, the parasitic capacitance of the entire HGA (suspension) will greatly increase. Would. Therefore, the electrodes 135a to 135d
On the back side of the gimbal 130 is partially removed,
The through holes 138 are formed by the removed portions to form the electrodes 135a to 135a.
It is necessary to prevent the occurrence of parasitic capacitance near 135d.

FIG. 2 shows the gimbal 13 of the HGA shown in FIG.
It is the perspective view which expanded and showed the vicinity of 0 through-hole 138, and was partly broken and shown. Here, in FIG.
Lead pattern 134a shown as being permanently installed
To 134d are supported on the insulating film 153 in the vicinity of the through holes 155 on the gimbal 154, respectively, and the two-layered lead pattern 152a and the insulating film 151a, the lead pattern 152b, the insulating film 151b, and the lead pattern 15 are stacked.
2C, the wiring of the insulating film 151c, the lead pattern 152d, and the wiring of the insulating film 151d. That is, here, the lead patterns 152a to 152a are formed on the insulating film 153 which is processed and arranged in a ladder shape on the gimbal 154.
When arranging a wiring formed by sequentially laminating 52d and insulating films 151a to 151d, each lead pattern 152a to 152d of the insulating film 153 bridged over the through hole 155 is provided.
In the extending direction of the lead patterns 152a to 152d of the through holes 155.
1 or smaller than the length w1, four wires including the respective lead patterns 152a to 152d are arranged so as to intersect the insulating film 153 only directly above the through hole 155. Is shown. 2, the load beam 130 shown in FIG. 1 is schematically shown, and the load beam 132 is located below the gimbal 154 (that is, the gimbal 154).
(The side opposite to the insulating film 153 when viewed from above).

In short, in the HGA shown in FIG. 2, the insulating film 153 intersects with each of the four lead patterns 152a to 152d only above the through hole 155 of the gimbal 154, and the gimbal 154 and the lead pattern 152a to 152d.
There is a structural feature in that a distance is provided between the gimbal 154 and the gimbal 154 at a distance corresponding to the thickness of the insulating film 153, and this distance is maintained at any position on the gimbal 154.

FIG. 3 is a side sectional view showing the detailed structure of the HGA in FIG. 2 in a direction perpendicular to the gimbal 164 including one lead pattern 162. This HG
In A, the gimbal 164 formed at equal intervals by partially penetrating and removing the load beam 165 at a predetermined interval is provided, and the gimbal 164 is partially spaced so as to be larger than the gimbal 164 interval. By performing the penetration removal, the insulating films 163 formed at regular intervals are separated by the gimbal 16.
4 so that the entire space of the HGA is formed to be enlarged by the through hole 166 formed around the gimbal 164 and the periphery of the insulating film 163. This shows a state in which a lead pattern 162 and an insulating film 161 are stacked on the insulating film 163 in this order. Here, the interval between the gimbals 164 corresponds to the length w1 shown in FIG.
Corresponds to the length w2 shown in FIG.

In short, in the HGA shown in FIG. 3, a through hole 166 corresponding to the through hole 966 of the HGA shown in FIG. 14 is obtained, and the insulating film 163 corresponding to the insulating film 963 is partially penetrated and removed. This is a form in which the spatial range of the entire HGA is enlarged, and the parasitic capacitance between the lead pattern 162 and the gimbal 164 is such that the insulating film 163 is removed between the lead pattern 162 and the gimbal 164. Due to the structure, the parasitic capacitance is reduced as compared with the parasitic capacitance between the HGA lead pattern 963 and the gimbal 964 shown in FIG.

In the HGA shown in FIG. 3, the load beam 165 and the gimbal 164 are both made of stainless steel plate such as SUS304T.
In the case of 65, the thickness is 50-100 (μm), and the gimbal 1
In the case of 64, a case where the thickness is about 25 (μm) can be exemplified. Further, a case where the material of the insulating films 161 and 163 is a polyimide can be exemplified, but it is particularly preferable to use a material of the insulating film 163 having a small dielectric constant.

When manufacturing such an HGA, for example, the load beam 165 and the gimbal 164 are fixed by spot welding at a plurality of points, the insulating film 163 is shaped into a ladder shape by etching, and then the insulating film is formed by a thin film process. Wirings comprising a lead pattern 161 and a lead pattern 162 are formed by lamination, and the components manufactured at these steps are bonded together with an adhesive to obtain a configuration as shown in FIG.

However, in such a configuration, the insulating film 163 does not have sufficient mechanical strength to support the load received from the lead pattern 162 or the insulating film 161, or the wiring composed of the insulating film 161 and the lead pattern 162 cannot be used. Wiring and load beam 1 by bending due to own weight
65 is not kept parallel, the insulating film 16
The width (length w2) of No. 3 is increased to obtain a configuration as shown in FIG.

In other words, in the HGA shown in FIG. 4, the gimbal 194 formed at equal intervals is provided on the load beam 196 by partially penetrating and removing the load beam 196 at a predetermined interval. It is assumed that a through hole 196 is formed, and an insulating film 193 having a width equal to the interval between the gimbals 194 and formed with an interval corresponding to the width of the gimbal 194 is formed above the interval between the gimbals 194. With the configuration provided so as to be positioned, the through hole 196 formed around the gimbal 194 and the insulating film 19 are formed.
3 shows that the entire space of the HGA is formed so as to be enlarged, and that a lead pattern 192 and an insulating film 191 are further laminated on the insulating film 193 in this order. That is, here, the width of the insulating film 193 is increased to the full gap between the gimbals 194, so that the wiring by the insulating film 191 and the lead pattern 192 can be easily supported.

FIG. 5 is a side sectional view showing a detailed structure of an HGA for magnetic recording according to another embodiment of the present invention in a direction perpendicular to a gimbal including one lead pattern.
In this HGA, by partially removing the through holes at predetermined intervals, the through holes are partially removed on the load beams 175 formed at equal intervals so as to have an interval larger than the interval between the load beams 175. Thus, the gimbal 174 is provided at equal intervals, and the gimbal 174 is provided.
The insulating film 173 formed at an equal interval by partially removing the through hole so as to have an interval larger than the interval of the gimbal 174 is provided so as to be located above the interval of the gimbal 174. It is assumed that the entire space of the HGA is enlarged and formed by the through hole 176 formed around the beam 175 and the gimbal 174 and around the insulating film 173.
Further, on these insulating films 173, lead patterns 172,
This figure shows a state in which the insulating films 171 are stacked in this order. That is, in the case of this HGA, unlike the case of the embodiment, the load beam 1 is different from that of the HGA shown in FIG.
75 is also partially penetrated to be used for forming the through hole 176.

In this HGA, the insulating film 173, the lead pattern 172, the insulating film 171, and the gimbal 174
May have the same configuration as that of the HGA shown in one embodiment,
The conditions and manufacturing method to be satisfied are the same as those in the embodiment, but in the case of this HGA, the through holes 176 around the gimbal 174 and the load beam 175 and the insulating film 1
Since the entire space of the HGA formed by the periphery of the HGA 73 is enlarged, the case of the HGA shown in the embodiment and FIG.
5 has the effect of further reducing the overall parasitic capacitance as compared with the case of the HGA shown in FIG. 5, thereby increasing the resonance frequency.

FIG. 6 is a side sectional view showing a detailed structure of a magnetic recording HGA according to another embodiment of the present invention in a direction perpendicular to a gimbal including one lead pattern.
The HGA has a configuration in which a gimbal 184 composed of a convex-concave body in which a concave portion is integrally formed by forming a step between convex portions having equal intervals on the load beam 185 and a convex portion of the gimbal 184 is provided. The insulating films 183 formed at equal intervals by partially removing the through-holes so as to have an interval larger than the interval of the (or concave) gimbal 1
The gap 1 is provided so as to be located above the concave portion of the gimbal 184.
86 and the periphery of the insulating film 183, the entire space of the HGA is formed to be enlarged.
A lead pattern 182 and an insulating film 181 are stacked and provided in this order on the convex portion of FIG. That is, this HG
In the case of A, unlike the case of one embodiment and the other embodiments, as in the case of the HGA shown in FIG. 16, the shape of the gimbal 184 itself is devised and partially removed to form a gap 186 around the recess. Is formed.

In the case of this HGA, the insulating film 183, the lead pattern 182, and the insulating film 181 may have the same configuration as in the case of the HGA shown in one embodiment, and the conditions to be satisfied by them and the manufacturing method of the one embodiment are the same. As in the case of the HGA, the convex portion of the gimbal 184 is formed as shown in FIG.
By providing the gimbal 164 at the same position as the arrangement of the gimbal 164, a gap 186 formed around the concave portion of the gimbal 184 is arranged instead of the through hole 166, and the gap 18 formed around the concave portion of the gimbal 184 is formed.
Since the entire space formed by the HGA 6 and the periphery of the insulating film 183 is enlarged, the distance between the lead pattern 182 and the gimbal 184 can be increased as compared with the case of the HGA shown in FIG. By lead pattern 1
The parasitic capacitance between 82 and gimbal 184 can be further reduced.

Incidentally, in paragraphs [0004] to [0008] of Japanese Patent Application Laid-Open No. 9-282624, generally, in the case of an HGA using a metal suspension, a parasitic capacitance is formed between a conductive lead pattern and a gimbal. Is stated to occur. This is one of the main causes of the resonance phenomenon. The following is the technical background of the HGA according to each of the above-described embodiments, and the resonance frequency of the circuit (wiring) on the suspension of the HGA shown in FIG. The case of obtaining using an approximate equivalent circuit will be described.

FIG. 7 shows an approximate equivalent circuit including a part of a conventional HGA and a recording or reproducing head. This equivalent circuit is used to explain the resonance phenomenon in paragraphs [0005] to [0007] of Japanese Patent Application Laid-Open No. 9-282624. Here, the lead pattern on the suspension and the recording or reproducing head are described. And the inductance of the lead pattern is L
L1 and LL2, the inductance of the recording or reproducing head is shown as LH, and the resistance of the recording or reproducing head is shown as RH. Terminals 1 and 2 in FIG. 7 are electrodes on the suspension, and electrodes 935a and 935b in FIG.
Or, electrodes 935c and 935d are shown.

Here, the resistance value of the lead pattern,
The capacitance between the lead patterns, the capacitance component inside the recording or reproducing head is omitted because it is minute,
Inductance LL1, inductance L from terminal 1
H, resistance RH, inductance LL2, parasitic capacitance C _G
When the resonance frequency f _{0 of the} circuit reaching the ground potential (gimbal or load beam) via the above equation is calculated, the relationship f ₀ = 1 / {2π (LC) ^1/2 } is obtained in the same manner as in the case of the above-mentioned equation (1). Becomes Here, L = LL1 + LL2 + LH,
A capacitance C = parasitic capacitance C _G. In the case of this equivalent circuit, if attention is paid only to the resonance frequency f ₀ , a problem occurs in which an excessive current flows in a circuit including a recording or reproducing head. However, if the parasitic capacitance _CG is reduced, the resonance frequency f ₀ is reduced. The recording / reproducing frequency width can be increased.

Next, the case where the equivalent circuit of the wiring on the suspension is shown in FIG. 8 will be described. In FIG. 8, terminal 1
A point obtained by adding the capacitance C _{G 'for} both the ground potential lead patterns extending from the terminal 2 which is differs from the equivalent circuit in the case of FIG. 7, the resonance frequency f ₀ of substantially approximately 7 It is expressed by Equation 1 as in the equivalent circuit in the case. However, in the case of the equivalent circuit of FIG. 8, the incidental condition of Expression 1 is a capacitance C = _CG · f (capacitance of one-sided wiring), and L = LL1 + LL2 + LH.

Therefore, in equation (1), L = 130 (n
H), R = 16 (Ω) (these constants correspond to equivalent circuits of a circuit including an inductive recording head), and the parasitic capacitance C _G [pF] and the resonance frequency f ₀ [MHz]
Is as shown in FIG. FIG. 9 shows that the resonance frequency f ₀ can be increased (increased) if the parasitic capacitance _CG is reduced.

Next, the case of calculating the parasitic capacitance C _G of HGA conventional HGA and an embodiment. Generally, the capacitance C can be considered to be substantially equal to εS / d with respect to the area S of the counter electrode, the relative permittivity ε of the insulator between electrodes, and the distance d between the electrodes. Conventional HG shown in FIG.
In A, to reduce the area S of the opposite electrodes by the gimbal 964 is provided a through hole 966, but attempts to decrease the parasitic capacitance C _G, the HGA of an embodiment shown in FIG. 3, the area of the counter electrode S in addition to the reduction, even considering the dielectric constant epsilon, which attempted to further reduce the parasitic capacitance C _G. In the case of the HGA of FIG. 14, the material of the insulating film 963 between the lead pattern 962 and the gimbal 964 is polyimide, and its relative permittivity is 3.3. On the other hand, in the HGA of one embodiment shown in FIG. 3 in which the insulating film 963 is partially penetrated and removed, the relative dielectric constant between the lead pattern 162 and the gimbal 164 is the air value ε = 1. since the parasitic capacitance between the lead patterns 162 and the gimbal 164 C _G is 1 / 3.3 as compared with the case of the HGA in FIG. 14
To decline.

In the HGA shown in FIG. 14, the capacitance per unit area of the lead pattern 962 to the gimbal 964 is C1, and the lead pattern 962 to the load beam 965 is C1.
The capacitance per unit area of the insulating film 963
Is made of polyimide, the dielectric constant ε1 of ε1 = 3.
3 × 8.854E-12, permittivity ε0 in air is expressed as ε0 =
8.854E-12, the thickness of the insulating film 963 is x1 (μ
m), and the thickness of the gimbal 964 is x2 (μm),
When the relationship x = x1 + x2 holds, the capacitance C
1, C2 are respectively C1 = ε1 / x1, C2 = 1 /
{X / ε1-x2 / (ε1) ⁻¹ − (ε0) ⁻¹ }.

Here, the capacitance between the opposing electrodes when the two kinds of dielectrics are distributed between the opposing metal plates in a layered manner in parallel with the electrode plate is described in, for example, "Electromagnetics", edited by The Institute of Electrical Engineers of Japan. , Ohm Publishing Co., Ltd., page 94, equation (5.48).

In the case of the HGA shown in FIG. 14, the thickness of each component is adjusted according to paragraph [002] of JP-A-9-282624.
6], x1 = 5 (μ
m), when x2 = 25 (μm), C1 = 5.8
(F), C2 = 0.33 (μF). Gimbal 96
4 and the area ratio of the through-hole 966 are described in JP-A-9-28262.
Gimbal 96 according to [Example] in Japanese Patent Publication No. 4
The area of the through hole 966 can be set to 2 with respect to the area 1 of 4.
The parasitic capacitance C0 per unit area of the entire lead pattern 962 is obtained from the weighted average of the occupied areas of the capacitances C1 and C2 as C0 = (C1 + 2C2) /3=2.2 (μ)
F).

On the other hand, in the case of the HGA shown in FIG. 3, since the insulating film 963 shown in FIG. 14 is partially penetrated and removed, the static electricity per unit area of the lead pattern 162 and the gimbal 164 in the direction of the lead pattern 162 is obtained. The capacitance per unit area is C2 ', the capacitance per unit area of a portion of the lead pattern 162 and the load beam 165 between the facing metal plate and the insulating film 163 and air is C2', and the unit of the lead pattern 162 and the load beam 165 is C1 '. Assuming that the capacitance per unit area of the portion of the capacitance per area between the opposed metal plates consisting only of air is C3 ', x = x1 +
x2, the capacitances C1 ', C1
2 ′ and C3 ′ are respectively C1 ′ = ε0 / x1, C2 ′
= 1 / {x / ε1-x2 / (ε1) ⁻¹ − (ε0) ⁻¹ },
C3 '= ε0 / x.

In these relational expressions, the dielectric constant ε1 = 3.3 × 8.854E-12 when the insulating film 163 is made of polyimide and the dielectric constant in the air as in the case of the capacitance calculation in the case of the HGA in FIG. ε0 = 8.854E-12, thickness x1 of insulating film 163 = 5 (μm), thickness x2 of gimbal 164 = 25
(Μm), C1 ′ = 1.8 (μF), C1 ′ = 1.8 (μF)
2 ′ = 0.33 (μF) and C3 ′ = 0.30 (μF).

As described above, in the HGA of FIG. 3, since the thickness of the gimbal 164 is five times as large as the thickness of the insulating film 163, the influence of the dielectric constants ε0 and ε1 on the capacitances C2 ′ and C3 ′. Is small, and the capacitance C2 'is almost equal to the capacitance C3'.
Becomes equal to Therefore, the area of the insulating film 163 is HGA
(Suspension) impact on the whole of the parasitic capacitance C _G is small.

That is, even if the distribution (occupied area) of the insulating film 163 in the horizontal direction in the HGA shown in FIG. 3 is large as in the state shown in FIG. 4, the insulating film 163 is not connected to the lead pattern 162 and the gimbal. parasitic capacity of the whole HGA unless disposed between the 164 C _G it can be seen that hardly changes. If the ratio of the areas forming the capacitances C1 ', C2', C3 'is, for example, 2: 1: 3, the parasitic capacitance C0' per unit area generated in the HGA lead pattern 162 shown in FIG. C0 '= (2C1' + C
2 ′ + 3C3 ′) / 6 = 0.79 (μF).

When the area occupied by the insulating film 163 in FIG. 3 is further increased and the ratio of the areas forming the capacitances C1 ', C2', C3 'is, for example, 1: 2: 0, FIG. The HGA has the configuration shown in FIG. In the case of the HGA of FIG. 4, the parasitic capacitance C per unit area generated in the lead pattern 192
0 ″ is on average C0 ″ = (1C1 ′ + 2C2 ′) / 3 =
0.81 (μF). This is almost the same as the capacitance C0 'of the HGA shown in FIG. That is, if it is difficult to support the lead pattern 162 and the accompanying insulating film 161 by the insulating film 163 in FIG.
4 by increasing the lateral width shown in FIG.
Changing the structure of the HGA shown in, increasing the width of the parasitic capacitance C _G due to the change of the structure it is found that requires only very small.

[0055] Finally, described improvement effect of the resonance frequency due to a reduction in parasitic capacitance C _G in the equivalent circuit shown in FIGS. 7 and 8. The contents described above, that is, the parasitic capacitance C0 ′ = 0.79 (μF) generated per unit area of the lead pattern 162 in the HGA of FIG.
Is reduced to 0.37 times of the parasitic capacitance C0 = 2.2 (μF) generated per unit area of the lead pattern 962 in the above, and if calculated using Expression 1, the resonance frequency in the HGA of FIG. It can be seen that the resonance frequency in the HGA of FIG. 14 is increased to about 1.7 times.

Further, referring to FIG. 9, for example, like the HGA of each embodiment, the insulating films 163, 193, 173, 18
Assuming that the parasitic capacitance value in the case of the HGA as shown in FIG. 14 in which no gap is provided in C.3, that is, the product of the parasitic capacitance per unit area and the lead pattern area is C = 20 (pF), the HGA If the above configuration is changed from the structure shown in FIG. 14 to the structure shown in FIG.
_G is reduced to 7.4 (pF), so that the resonance frequency in FIG. 9 is from about 100 (MHz) to about 170 (MH).
z). Strictly speaking, the transfer functions of the equivalent circuits shown in FIGS. 7 and 8 are not completely the same as the actual transfer circuit of the wiring on the HGA (suspension), but these equivalent circuits have the resonance frequency. This is effective as a means for estimating an approximate improvement range.

The effect of partially removing the insulating film described above is due to the gimbal 974 of the insulating film 973 in the HGA shown in FIG. 5, that is, the HGA shown in FIG.
The insulating film 175 which does not contact the gimbal 174 as shown in FIG. 5 by penetrating and removing the portion including the portion in contact with the HGA shown in FIG.
As shown in FIG. 16, the insulating film 983 in the HGA shown in FIG. 16 is removed by penetrating and including a portion in contact with the convex portion of the gimbal 984, thereby forming an insulating film 183 not in contact with the convex portion of the gimbal 184. Also appears in.

[0058]

As described above, according to the HGA for magnetic recording of the present invention, the insulating film between the gimbal and the lead pattern on the suspension is partially penetrated and removed.
Because the structure can expand the entire space, HG
The parasitic capacitance of the entire A (suspension) is reduced and the resonance frequency is increased. As a result, the upper limit of the data transfer frequency for recording / reproduction in a magnetic disk device or a magneto-optical disk device is increased. It is possible to improve the data transfer speed of recording / reproducing.

[Brief description of the drawings]

FIG. 1 is a plan view showing a basic configuration of a magnetic recording HGA according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a portion near a through hole of a gimbal provided in the HGA shown in FIG.

FIG. 3 is a side sectional view showing a detailed structure of the HGA in FIG. 2 in a direction perpendicular to a gimbal including one lead pattern.

FIG. 4 is a side sectional view in a case where the detailed structure of the HGA shown in FIG. 3 is partially changed.

FIG. 5 is a side sectional view showing a detailed structure of an HGA for magnetic recording according to another embodiment of the present invention in a direction perpendicular to a gimbal including one lead pattern.

FIG. 6 is a side sectional view showing a detailed structure of an HGA for magnetic recording according to another embodiment of the present invention in a direction perpendicular to a gimbal including one lead pattern.

FIG. 7 shows an approximate equivalent circuit including a part of a conventional HGA and a recording or reproducing head.

8 shows an equivalent circuit in a case where a capacitance with respect to a ground potential is added to the equivalent circuit shown in FIG. 7;

FIG. 9 illustrates a relationship between a parasitic capacitance and a resonance frequency in the equivalent circuit illustrated in FIG. 8;

FIG. 10 is a plan view showing a basic configuration of a conventional HGA for magnetic recording.

11 is a side view of the HGA shown in FIG. 10 as viewed from a lateral direction.

FIG. 12 is an enlarged perspective view of the vicinity of a through hole of the gimbal of the HGA shown in FIG.

FIG. 13 is a side cross-sectional view showing a detailed structure of a conventional HGA without a through-hole in a direction along one lead pattern.

14 is a side sectional view showing a detailed structure of the HGA in FIG. 12 in a direction along one lead pattern.

FIG. 15 is a side sectional view showing a detailed structure of another conventional HGA having a through hole in a direction along one lead pattern.

FIG. 16 is a side sectional view showing a detailed structure of another conventional HGA having a through hole in a direction along one lead pattern.

[Explanation of symbols]

130,154,164,174,184,194,8
64,954,964,974,984 Gimbals 131,931 Sliders 132,165,175,185,195,865,9
32,965,975,985 Load beam 133,933 Base plate 134a-134d, 152a-152d, 162,1
72,182,192,862,934a-934d,
952a to 952d, 962, 972, 982 Lead pattern 135a to 135d, 935a to 935d Electrode 138, 155, 166, 176, 196, 938, 9
55,966,976 through holes 140,141,151a-151d, 153,16
1,163,171,173,181,183,19
1,193,861,863,951a-951d, 9
53a to 953d, 961, 963, 971, 973
981,983 insulating film 186,986 void

Claims (6)

[Claims] 1. A head gimbal assembly for magnetic recording, comprising a slider for a magnetic head, a metal suspension supporting the slider, and a lead pattern for the magnetic head supported on the suspension via an insulator. 3. The head gimbal assembly for magnetic recording according to claim 1, wherein the suspension is partially removed at equal intervals, and the insulator supports the lead pattern only at a position above a removed portion of the suspension. 2. The head gimbal assembly for magnetic recording according to claim 1, wherein the removed portion of the suspension is provided so as to penetrate therethrough. 3. The head gimbal assembly for magnetic recording according to claim 2, wherein the suspension comprises a metal gimbal disposed on a metal load beam.
The gimbal is partially penetrated and removed at equal intervals to form a through hole, and the insulator supports the lead pattern only at a position above the through hole of the gimbal. Head gimbal assembly for recording. 4. The magnetic recording head gimbal assembly according to claim 3, wherein the load beam is partially removed at an equal interval equal to or less than an interval of the gimbal to form a through hole, and the insulator is provided. A head gimbal assembly for magnetic recording, wherein the lead pattern is supported only at a position above the through hole of the gimbal connected to the through hole of the load beam. 5. A magnetic recording head gimbal assembly having a slider for a magnetic head, a metal suspension supporting the slider, and a lead pattern for the magnetic head supported on the suspension via an insulator. Wherein the suspension comprises a concave-convex body in which a concave portion is integrally formed by forming a step between convex portions having equal intervals, and the insulator is provided with the lead only at a position above the concave portion of the suspension. A head gimbal assembly for magnetic recording, which supports a pattern. 6. The head gimbal assembly for magnetic recording according to claim 5, wherein the suspension is configured by disposing a metal gimbal on a metal load beam.
The gimbal is formed of a convex-concave body in which a concave portion is integrally formed by forming a step between convex portions having equal intervals, and the insulator forms the lead pattern only at a position above the concave portion of the gimbal. A head gimbal assembly for magnetic recording characterized by supporting.