Flexure for disk drive

Abstract

To provide a flexure capable of suppressing movement of a liquid-type conductive adhesive supplied to a terminal along a conductive portion to a portion other than the terminal.SOLUTION: A flexure 15 has a metal base 40, a base insulating layer 41 formed on the metal base 40, a conductive portion 45a formed on the base insulating layer 41, a terminal 61, and an extension portion 70 for bypassing. The conductive portion 45a has a conductor 42a and a cover layer 43a covering the conductor 42a. A conductive adhesive 50 is supplied to the terminal 61. The extension portion 70 for bypassing is formed in the middle of a length direction of the conductive portion 45a and extends from a side surface 80 of the conductive portion 45a along the base insulating layer 41 in a direction intersecting the length direction of the conductive portion 45a.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a flexure for a disk device used in an information processing device or the like, and more particularly to a wiring portion of the flexure. [Background technology]

[0002] An actuator made of a piezoelectric element is sometimes mounted on a flexure of a suspension used in a disk drive (see, for example, Patent Document 1). A conductive adhesive containing a conductive material such as silver particles is sometimes used to fix the actuator to the gimbal part of the flexure. The conductive adhesive has the function of fixing the actuator to the terminal of the gimbal part and the function of electrically connecting the actuator to the wiring part.

[0003] The liquid conductive adhesive before hardening has fluidity. This can cause some of the conductive adhesive to flow out from the terminal toward the wiring portion. The wiring portion of the flexure has a conductor parallel portion consisting of multiple conductor portions. In such a conductor parallel portion, a narrow gap is formed between adjacent conductor portions. The gap extends in the longitudinal direction of the conductor portions.

[0004] The conductive adhesive is supplied to the terminals of the actuator mounting section. There have been cases where the liquid conductive adhesive supplied to the terminals has traveled along the conductor section to areas other than the terminals. For example, in the parallel conductor section, there are narrow gaps between adjacent conductor sections. This raised concerns that the conductive adhesive could be transported far away due to capillary action.

[0005] Conductive adhesives contain conductive materials such as silver particles. As a result, the conductive material may migrate along the conductor and adhere to unexpected locations, and the conductive particles may become detached from the wiring for some reason. Conductive material that has detached from the wiring may cause problems in the electrical circuits of the disk drive or even cause the disk drive to crash. For this reason, it is necessary to prevent the liquid conductive adhesive from migrating along the wiring.

[0006] The flexure described in Patent Document 2 has a wall portion to prevent the liquid conductive adhesive from moving toward the part to be protected (e.g., a reference hole). The liquid conductive adhesive is supplied to the terminal of the actuator mounting portion. The wall portion is formed as an island-shaped protrusion between the terminal and the part to be protected. The height of the wall portion is greater than the height of the terminal. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2020-135906 [Patent Document 2] Japanese Patent Application Publication No. 2019-046517 Summary of the Invention [Problem to be solved by the invention]

[0008] Conventional wall portions used to prevent the liquid conductive adhesive from flowing toward the area to be protected are island-shaped protrusions that are independent of the wiring. Such wall portions can block the liquid conductive adhesive that flows out from the terminals before it reaches the area to be protected. However, conventional wall portions cannot prevent the liquid conductive adhesive supplied to the terminals from moving along the wiring.

[0009] An object of the present invention is to provide a flexure for a disk drive that can prevent a liquid conductive adhesive supplied to a terminal from moving along the wiring portion to areas other than the terminal. [Means for solving the problem]

[0010] A flexure for a disk drive according to one embodiment includes a metal base, an insulating base layer formed on the metal base, a first conductor portion including a conductor formed on the insulating base layer and a cover layer covering the conductor, a gap formed between adjacent conductor portions; The first conductor portion is electrically connected to the conductor of the first conductor portion, and a conductive adhesive is supplied. The actuator is fixed by the conductive adhesive. terminals and a recess whose height from the base insulating layer is lower than that of the first conductor portion and which is continuous with the gap; and a detour extension formed midway along the length of the first conductor. The actuator is formed at a position not overlapping the actuator and is present in the recess, The detour extension extends from the side surface of the first conductor along the insulating base layer in a direction intersecting the longitudinal direction of the first conductor. The detour extension is integral with the first conductor and is continuous with the side surface of the first conductor.

[0011] In the embodiment, a conductor parallel section in which the first conductor section and a plurality of other conductor sections are arranged parallel to each other, and a conductor parallel section formed between the conductor sections adjacent to each other in the conductor parallel section and extending in the length direction of the conductor sections along the conductor sections. The aforementioned The detour extending portion may be provided between the conductor parallel portion and the terminal.

[0012] The height of the detour extension portion from the insulating base layer may be equal to the height of the first conductor portion from the insulating base layer. Furthermore, one of both side surfaces of the first conductor portion may be continuous with the gap of the parallel conductor portion, and the detour extension portion may extend from the one side surface of the first conductor portion in a direction intersecting with the longitudinal direction of the first conductor portion.

[0013] As shown in the example of Fig. 4, the detour extension may extend from the one side surface of the first conductor in a direction perpendicular to the longitudinal direction of the conductor. As shown in the example of Fig. 8, the detour extension may include a neck portion connected to the side surface of the first conductor and a widened portion connected to the neck portion and having a width greater than that of the neck portion. As shown in the example of Fig. 9, the detour extension may include a neck portion connected to the side surface of the first conductor and a plurality of fork-shaped protrusions connected to the neck portion.

[0014] As shown in the example of Fig. 10, the detour extension may have a neck portion connected to the side surface of the first conductor portion and a plurality of protrusions connected to the neck portion and extending in a direction facing the terminal. As shown in the example of Fig. 11, the detour extension may have a spiral-shaped protrusion connected to the side surface of the first conductor portion. As shown in the example of Fig. 12, the detour extension may have a first detour extension connected to one side surface of the first conductor portion and a second detour extension connected to the other side surface of the first conductor portion. [Effects of the Invention]

[0015] According to the flexure of this embodiment, the bypass extension can prevent the liquid conductive adhesive supplied to the terminal from moving along the conductor to areas other than the terminal. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing an example of a disk device. [Figure 2] FIG. 2 is a plan view showing an example of a suspension used in the disk device. [Figure 3] FIG. 2 is a plan view of a portion of the flexure according to the first embodiment. [Figure 4] FIG. 4 is an enlarged plan view of a portion of the flexure shown in FIG. 3. [Figure 5] FIG. 5 is a cross-sectional view of the wiring portion taken along line VV in FIG. 4. [Figure 6] FIG. 6 is a cross-sectional view of the wiring portion taken along line VI-VI in FIG. 4. [Figure 7] FIG. 7 is a cross-sectional view of the wiring portion taken along line VII-VII in FIG. [Figure 8] FIG. 10 is a plan view of a portion of a flexure according to a second embodiment. [Figure 9] FIG. 10 is a plan view of a portion of a flexure according to a third embodiment. [Figure 10] FIG. 10 is a plan view of a portion of a flexure according to a fourth embodiment. [Figure 11] FIG. 11 is a plan view of a portion of a flexure according to a fifth embodiment. [Figure 12]FIG. 13 is a plan view of a portion of a flexure according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] [First embodiment] A flexure for a disk drive according to a first embodiment will be described below with reference to FIGS. Fig. 1 is a perspective view showing a hard disk drive as an example of a disk device. The disk device 1 shown in Fig. 1 includes a case 2, a disk 4 that rotates around a spindle 3, a carriage 6 that rotates around a pivot shaft 5, a voice coil motor 7 that drives the carriage 6, and a controller 8.

[0018] An arm 10 is attached to the carriage 6. A disk drive suspension (hereinafter simply referred to as the suspension) 11 is attached to the tip of the arm 10. A slider 12 that constitutes a magnetic head is mounted on the tip of the suspension 11. When the disk 4 rotates, an air bearing is formed between the disk 4 and the slider 12. When the carriage 6 is rotated by the voice coil motor 7, the slider 12 moves to the desired track on the disk 4.

[0019] FIG. 2 is a plan view showing an example of a suspension 11. The suspension 11 includes a base plate 13, a load beam 14, and a flexure 15. The base plate 13 is fixed to an arm 10 (shown in FIG. 1) of the carriage 6. The direction indicated by arrow X in FIG. 2 is the longitudinal direction of the suspension 11. In this specification, the direction indicated by arrow X1 may be referred to as the front of the suspension 11, and the direction indicated by arrow X2 may be referred to as the rear of the suspension 11.

[0020] The flexure 15 is disposed along the load beam 14. A tail portion 16 of the flexure 15 extends rearward of the suspension 11. A gimbal portion 17 is provided near the tip of the flexure 15. The slider 12 is disposed on the gimbal portion 17.

[0021] FIG. 3 shows the tip of the flexure 15. The gimbal portion 17 of the flexure 15 includes a swingable tongue portion 20. The slider 12 is attached to the tongue portion 20. The slider 12 functions as a magnetic head for accessing the disk 4, such as writing and reading data. A plurality of elements 21, such as MR elements, are provided at the end of the slider 12. The elements 21 convert magnetic signals into electric signals. The suspension 11 and the slider 12 form a head gimbal assembly. A connection terminal 22 of the slider 12 is connected to the wiring portion 30 of the flexure 15.

[0022] 3, the gimbal section 17 is provided with a first actuator mounting section 31 and a second actuator mounting section 32. A first actuator 33 is disposed on the first actuator mounting section 31. The first actuator 33 is disposed near one side surface 12a of the slider 12. A second actuator 34 is disposed on the second actuator mounting section 32. The second actuator 34 is disposed near the other side surface 12b of the slider 12.

[0023] The first actuator 33 and the second actuator 34 each include a piezoelectric element made of a piezoelectric material such as lead zirconate titanate (PZT). The first actuator 33 and the second actuator 34 move the slider 12 in the sway direction (indicated by the double-headed arrow Y in FIG. 3) by deformation that occurs when a voltage is applied to the piezoelectric element.

[0024] The gimbal portion 17 of the flexure 15 shown in FIG. 3 is generally symmetrical with respect to the center line Z1 extending in the length direction of the flexure 15. For example, the shapes of the left and right sides may differ slightly, or the number of wires may differ between the left and right sides. The wiring portion 30 has a first wiring portion 30a extending along one side surface 12a of the slider 12 and a second wiring portion 30b extending along the other side surface 12b of the slider 12. The following description will be given using the first wiring portion 30a as a representative, but the second wiring portion 30b also has substantially the same configuration as the first wiring portion 30a.

[0025] Fig. 4 is an enlarged plan view of a portion of the wiring portion 30 of the flexure 15 shown in Fig. 3. Fig. 5 is a cross-sectional view of a portion of the wiring portion 30 taken along line VV in Fig. 4. As shown in Fig. 5, the wiring portion 30 includes a metal base 40 made of a thin stainless steel plate, an insulating base layer 41 formed on the metal base 40, a plurality of conductors 42 along the insulating base layer 41, and a cover layer 43 covering the conductors 42. The metal base 40 forms the main body of the flexure 15 and can bend elastically in the thickness direction.

[0026] The conductor 42 is made of a metal such as copper having low electrical resistance. The base insulating layer 41 and the cover layer 43 are made of an electrically insulating resin such as polyimide. The thickness of the base insulating layer 41 is, for example, 5 to 20 μm. The thickness of the conductor 42 is, for example, 4 to 16 μm. The thickness of the cover layer 43 is, for example, 2 to 10 μm. The conductor 42 and the cover layer 43 form a conductor portion 45.

[0027] 4 and 5, the wiring section 30 includes a parallel conductor section 30X in which a plurality of conductor sections 45 are arranged parallel to one another. The parallel conductor section 30X has gaps 46 formed between adjacent conductor sections 45. These gaps 46 extend in the longitudinal direction of the conductor sections 45. If a liquid conductive adhesive 50 enters these gaps 46, capillary action may cause the conductive adhesive 50 to move along the gaps 46 to an unexpected position.

[0028] The conductive adhesive 50 contains a conductive material such as silver particles. If the conductive material contained in the conductive adhesive 50 moves along the conductor portion 45, the conductive material may become detached from the wiring portion 30 for some reason. Conductive particles that become detached from the wiring portion 30 may cause problems in the disk drive. For this reason, in this embodiment, the first wiring portion 30a and the second wiring portion 30b are provided with detour extensions 70 and 71, respectively, to suppress the movement of the conductive adhesive 50. The detour extensions 70 and 71 will be described in detail later.

[0029] 3, a first terminal 61 and a second terminal 62 are formed on the first actuator mounting portion 31. One end of the first actuator 33 is fixed to the first terminal 61 with a conductive adhesive 50. The first terminal 61 is electrically connected to the first conductor portion 45a. The other end of the first actuator 33 is fixed to the second terminal 62 with the conductive adhesive 50. The second terminal 62 is electrically connected to the second conductor portion 45b.

[0030] A third terminal 63 and a fourth terminal 64 are formed on the second actuator mounting portion 32. One end of the second actuator 34 is fixed to the third terminal 63 with a conductive adhesive 50. The third terminal 63 is electrically connected to the third conductor portion 45c. The other end of the second actuator 34 is fixed to the fourth terminal 64 with the conductive adhesive 50. The fourth terminal 64 is electrically connected to the fourth conductor portion 45d.

[0031] The first actuator mounting portion 31 and the second actuator mounting portion 32 are substantially symmetrical with respect to the imaginary center line Z1. The actuator mounting portions 31 and 32 have substantially the same configuration. Therefore, the following description will be given using the first actuator mounting portion 31 as a representative.

[0032] As shown in FIG. 4, a first conductor portion 45a forming part of the wiring portion 30 has a detour extension portion 70 formed near the first terminal 61. The bidirectional arrow L1 shown in FIG. 4 indicates the length direction of the first conductor portion 45a. The bidirectional arrow L2 indicates the width direction of the first conductor portion 45a. FIG. 6 is a cross-sectional view of a portion of the wiring portion 30 taken along line VI-VI in FIG. 4. FIG. 7 is a cross-sectional view of a portion of the wiring portion 30 taken along line VII-VII in FIG. 4.

[0033] The detour extension 70 is formed between the first terminal 61 and the conductor parallel portion 30X. The detour extension 70 has a shape that protrudes like a cape in the width direction of the first conductor portion 45a, midway along the length of the first conductor portion 45a. In other words, the detour extension 70 extends in a direction intersecting the length direction of the first conductor portion 45a (for example, a direction perpendicular to the length direction). The detour extension 70 is integral with the first conductor portion 45a and includes a conductor 42a made of copper and a cover layer 43a that covers the conductor 42a.

[0034] The conductor 42a of the detour extension 70 is made of the same copper as the conductor 42 of the first conductor portion 45a. The detour extension 70 is formed integrally with the first conductor portion 45a at the same time as the first conductor portion 45a is formed. Therefore, no special manufacturing process is required to form the detour extension 70.

[0035] 6, the height H1 of the detour extension 70 from the base insulating layer 41 is the same as the height H2 of the first conductor portion 45a. The detour extension 70 is formed integrally with the first conductor portion 45a. The detour extension 70 continues from the first conductor portion 45a in the width direction of the first conductor portion 45a.

[0036] Liquid conductive adhesive 50 (shown in FIG. 3) is supplied to first terminal 61. There is a possibility that part of the liquid conductive adhesive 50 supplied to terminal 61 will flow in the direction indicated by first arrow A1 in FIG. 4. Even if the conductive adhesive 50 does not flow immediately after application, it may overflow and flow out when actuators 33, 34 are mounted. For example, as indicated by the two-dot chain line 50a in FIG. 6, it is conceivable that the conductive adhesive 50 will adhere to the corner formed by the side surface 80 of the first conductor portion 45a and the base insulating layer 41.

[0037] The conductive adhesive 50 attached to the corner formed by the side surface 80 of the first conductor portion 45a and the base insulating layer 41 may flow in the direction of the first arrow A1 shown in FIG. 4. However, the flow of the conductive adhesive 50 flowing in the direction of the first arrow A1 is blocked by the detour extension portion 70. As a result, the conductive adhesive 50 flows around the detour extension portion 70 as shown by the second arrow A2. Therefore, the movement path of the conductive adhesive 50 becomes longer in accordance with the detour extension portion 70. This prevents the conductive adhesive 50 from reaching the parallel conductor portion 30X.

[0038] 4, there is a possibility that the conductive adhesive will flow toward the parallel conductor portion 30X. However, since there are no gaps 46 on the side surface 81 of the parallel conductor portion 30X, the conductive adhesive 50 is prevented from flowing through the parallel conductor portion 30X due to capillary action.

[0039] The above description is about the detour extension 70 provided on the first wiring portion 30a. The detour extension 71 provided on the second wiring portion 30b is similar to the detour extension 70 provided on the first wiring portion 30a, so a description of the other detour extension 71 will be omitted.

[0040] [Second to Sixth Embodiments] Flexures 15A-15E of the second to sixth embodiments will be described below with reference to Figures 8 to 12. In these flexures 15A-15E, parts common to the flexure 15 of the first embodiment are denoted by common reference numerals, and descriptions thereof will be omitted.

[0041] FIG. 8 is a plan view showing a portion of a flexure 15A according to the second embodiment. The wiring portion 30 of this flexure 15A has a detour extension 70A having a longer detour distance than the detour extension 70 of the first embodiment. The detour extension 70A has a neck portion 90 connected to the side surface 80 of the first conductor portion 45a and a widened portion 91 connected to the neck portion 90. The widened portion 91 has a width W1 greater than the width of the neck portion 90. The widened portion 91 has a length L3 greater than the length of the neck portion 90. As indicated by the dashed arrow in FIG. 8, the conductive adhesive flowing out of the terminal 61 detours around the widened portion 91.

[0042] 9 is a plan view showing a portion of a flexure 15B according to the third embodiment. The detouring extension 70B of this flexure 15B has a neck 90 connected to the side surface 80 of the first conductor 45a and a plurality of fork-shaped protrusions 100 connected to the neck 90 in order to further increase the detouring distance of the conductive adhesive. As indicated by the dashed arrows in FIG. 9, the conductive adhesive flowing out of the terminal 61 makes a large detouring route around the peripheries of the fork-shaped protrusions 100.

[0043] Fig. 10 is a plan view showing a portion of a flexure 15C according to the fourth embodiment. The detour extension 70C of this flexure 15C has a neck 90 continuing to a side surface 80 of the first conductor 45a, and a plurality of protrusions 110 continuing to the neck 90 and extending in a direction facing the terminals 61. As indicated by the dashed arrows in Fig. 10, the conductive adhesive flowing out from the terminals 61 detours around the protrusions 110 facing the terminals 61.

[0044] Fig. 11 is a plan view showing a portion of a flexure 15D according to the fifth embodiment. The detour extension 70D of this flexure 15D has a spiral-shaped protrusion 120 to further increase the detour distance. The spiral-shaped protrusion 120 is continuous with the side surface 80 of the first conductor portion 45a. As indicated by the dashed arrow in Fig. 11, the conductive adhesive flowing out from the terminal 61 makes a large detour along the spiral-shaped protrusion 120.

[0045] 12 is a plan view showing a portion of a flexure 15E according to the sixth embodiment. The flexure 15E has a first detour extension 70 and a second detour extension 70E. The first detour extension 70 is continuous with one side surface 80 of the conductor 45a, similar to the detour extension 70 of the first embodiment (FIGS. 3 to 7). The second detour extension 70E is continuous with the other side surface 82 of the conductor 45a.

[0046] In the flexure 15E shown in FIG. 12, the other side surface 82 of the conductor portion 45a is continuous with the side surface 81 of the parallel conductor portion 30X. Therefore, there is no risk of the conductive adhesive attached to the other side surface 82 of the conductor portion 45a moving due to capillary action. However, depending on the specifications of the suspension, the conductor portion 45a may be disposed between other wiring portions. The second detour extension portion 70E can prevent the conductive adhesive attached to the other side surface 82 of the conductor portion 45a from moving along the conductor portion 45a to another wiring portion away from the terminal 61. For this reason, it is effective to provide the detour extension portions 70, 70E on one side surface 80 and the other side surface 82 of the conductor portion 45a, respectively.

[0047] In carrying out the present invention, it goes without saying that the specific configurations of the metal base, wiring portion, terminals, etc. that constitute the flexure can be variously modified. Furthermore, the embodiments of the present invention can also be applied to a suspension that does not have an actuator mounting portion. The embodiments of the present invention can be applied to a wiring portion that has a terminal to which a conductive adhesive is supplied and a conductor portion connected to this terminal. [Explanation of symbols]

[0048] 1...disk device, 11...suspension, 15, 15A, 15B, 15C, 15D, 15E...flexure, 30, 30a, 30b...wiring portion, 30X...conductor parallel portion, 31, 32...actuator mounting portion, 33, 34...actuator, 40...metal base, 41...base insulating layer, 42, 42a...conductor, 43, 43a...cover layer, 45...conductor portion, 45a...first conductor portion, 46...gap, 50...conductive adhesive, 61...terminal, 70, 70A, 70B, 70C, 70D, 70E, 71...bypass extension portion, 80...side surface of first conductor portion.

Claims

1. Metal base and an insulating base layer formed on the metal base; a first conductor portion including a conductor formed on the insulating base layer and a cover layer covering the conductor; a gap formed between adjacent conductor portions; a terminal electrically connected to the conductor of the first conductor portion, to which a conductive adhesive is supplied, and to which an actuator is fixed by the conductive adhesive; a recessed portion that is equal to or lower than the height from the base insulating layer to the upper surface of the first conductor portion and that is continuous with the gap; a bypass extension portion that is formed in the recess at a position midway in the length direction of the first conductor portion so as not to overlap with the actuator, that extends from a side surface of the first conductor portion along the insulating base layer in a direction intersecting the length direction of the first conductor portion, and that is continuous with the side surface of the first conductor portion; A flexure for a disk device, comprising:

2. 2. The flexure according to claim 1, a conductor parallel section in which the first conductor section and a plurality of other conductor sections are arranged in parallel to each other; the gap is formed between the adjacent conductor portions of the parallel conductor section and extends along the conductor portions in a length direction of the conductor portions, The flexure has the detour extension formed between the conductor parallel portion and the terminal.

3. 2. The flexure according to claim 1, a flexure in which the height of the detour extension from the insulating base layer is the same as the height of the first conductor from the insulating base layer.

4. 3. The flexure according to claim 2, A flexure in which one of the two side surfaces of the first conductor portion is connected to the gap of the conductor parallel portion, and the bypass extension portion extends from the one side surface of the first conductor portion in a direction intersecting the longitudinal direction of the first conductor portion.

5. 5. The flexure according to claim 4, The flexure has a detouring extension extending from the one side surface of the first conductor in a direction perpendicular to the longitudinal direction of the conductor.

6. 2. The flexure according to claim 1, The detouring extension includes a neck portion connected to the side surface of the first conductor portion, and a widened portion connected to the neck portion and having a width greater than that of the neck portion.

7. 2. The flexure according to claim 1, The detouring extension has a neck portion connected to the side surface of the first conductor portion, and a plurality of fork-shaped protrusions connected to the neck portion.

8. 2. The flexure according to claim 1, The detouring extension has a neck portion connected to the side surface of the first conductor portion, and a plurality of protrusions connected to the neck portion and extending in a direction facing the terminal.

9. 2. The flexure according to claim 1, The detouring extension has a spiral-shaped protrusion continuing to the side surface of the first conductor.

10. 5. The flexure according to claim 4, A flexure having the detour extension portion connected to one side surface of the first conductor portion, and a second detour extension portion extending from the other side surface of the first conductor portion in a direction intersecting the longitudinal direction of the first conductor portion.

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