Cantilever and head gimbal assembly having the same

Abstract

The application discloses a cantilever suitable for a magnetic head flapper combination, which comprises a base metal layer as a bottom layer; a base dielectric layer formed on the base metal layer; a bottom conductive layer formed on the base dielectric layer; a separation dielectric layer formed on the bottom conductive layer; a top conductive layer formed on the separation dielectric layer, wherein one of a pair of write lines is arranged on the bottom conductive layer and the other of the pair of write lines is arranged on the top conductive layer; and a cover layer formed on the top conductive layer as a top layer. The application can reduce the wire impedance and the signal transmission loss, and increase the frequency bandwidth. The application also discloses a magnetic head flapper combination.

Description

Technical Field

[0001] This invention relates to an information recording disk drive unit, and more particularly to a suspension and a head gimbal assembly (HGA) having the suspension. Background Technology

[0002] Hard disk drives are common information storage devices. Figure 1a This is a schematic diagram of a typical hard disk drive 100. It includes a series of rotatable disks 101 mounted on a spindle motor 102, and a head stack assembly (HSA) 130. The HSA 130 includes at least one motor arm 104 and an HGA 10. Typically, a spinning voice-coil motor (VCM) (not shown) is used to control the movement of the motor arm 104.

[0003] refer to Figure 1b The HGA 10 includes a read / write head 103 embedded with a read / write sensor (not shown) and a cantilever 190 supporting the head 103. When the hard drive is operating, the spindle motor 102 causes the disk 101 to spin at high speed, and the head 103 flies above the disk 101 due to the air pressure generated by the rotation of the disk 101. Under the control of a voice coil motor, the head 103 moves radially across the surface of the disk 101. For different tracks, the head 103 can read data from the disk surface or write data to the disk 101.

[0004] The cantilever 190 includes a load bar 120, a substrate 150, a hinge 130, and a flexible element 140, all of which are assembled together. The load bar 120 is connected to the substrate 150 via the hinge 130. The load bar 120 is aligned with the flexible element 140. Furthermore, to increase the overall structural strength of the flexible element 140, the load bar 120 is welded to the flexible element 140. The substrate 150 serves to enhance the structural rigidity of the entire HGA. The flexible element 140 passes through the hinge 130 and the load bar 120. The flexible element 140 has a front end and a rear end, with flexible circuitry extending along its length. A magnetic head 103 is mounted on the front end of the flexible element 140.

[0005] Figure 1c A partial schematic diagram of the HGA is shown. Figure 1d A partial schematic diagram of the front end of the flexible component is shown. Multiple connecting contacts formed on the cantilever tongue are used to connect to the magnetic head 103. These connecting contacts are the endpoints of the flexible circuit 120. Generally, as... Figure 1eAs shown, the flexible circuit 120 extending to the contact point 117 includes a pair of read lines (R+, R-) 123a, 123b, a pair of write lines (W+, W-) 124a, 124b, a pair of oscillator lines (OSC+, OSC-) 125a, 125b, a ground line (GND) 126, and a dynamic flight altitude (DFH) control line 127.

[0006] Figure 1e , 1f For flexible element 150 along Figure 1d The cross-sectional view along sections AA and BB shows the layered structure of the flexible element 150. From top to bottom, the layered structure includes a cover layer 151, a signal conduction layer 152, a dielectric layer 153, and a metal layer 154. The aforementioned flexible circuit 120 is formed on the signal conduction layer. However, the write lines 124a and 124b are located in the same signal conduction layer, resulting in high impedance and high signal transmission loss, which fails to meet practical requirements and severely affects the write performance of the magnetic head.

[0007] Therefore, there is an urgent need for an improved cantilever assembly and magnetic head flap combination to overcome the above-mentioned defects. Summary of the Invention

[0008] One object of the present invention is to provide a cantilever component on which the write lines are stacked in two layers in the thickness direction of the flexible component, thereby reducing impedance and signal transmission loss, while increasing bandwidth.

[0009] Another object of the present invention is to provide a magnetic head flap assembly with a cantilever, wherein the write lines on the cantilever are stacked in two layers in the thickness direction of the flexible element, thereby reducing impedance and signal transmission loss, while increasing bandwidth.

[0010] To achieve the above objectives, the present invention provides a cantilever component suitable for magnetic head flap assemblies, comprising a flexible component with a layered structure, wherein the layered structure includes:

[0011] As the underlying base metal layer;

[0012] A base dielectric layer formed on top of the base metal layer;

[0013] A bottom conductive layer formed on top of the base dielectric layer;

[0014] A separating dielectric layer formed on top of the bottom conductive layer;

[0015] A top conductive layer formed on the separating dielectric layer, wherein one of a pair of write lines is disposed on the bottom conductive layer, and the other of the pair of write lines is disposed on the top conductive layer; and

[0016] A capping layer is formed on top of the top conductive layer as the top layer.

[0017] In one embodiment of the present invention, a pair of oscillator circuits are respectively provided on the top conductive layer and the bottom conductive layer.

[0018] Preferably, a pair of reading lines and a dynamic flight altitude control line are provided on the top conductive layer; a grounding line is provided on the bottom conductive layer.

[0019] Preferably, each line forms a corresponding contact point at the front of the flexible element to connect with the magnetic head of the magnetic head flap assembly.

[0020] Preferably, the write lines located on the top conductive layer and the bottom conductive layer are connected through vias.

[0021] Preferably, the oscillator circuitry located on the top conductive layer and the bottom conductive layer is connected via vias.

[0022] Preferably, the grounding line is connected to the base metal layer through a through-hole.

[0023] Preferably, the base dielectric layer and the separator dielectric layer are made of polyimide, and the base metal layer is made of stainless steel.

[0024] Preferably, each layer in the layered structure is stacked in the vertical direction.

[0025] A magnetic head flap assembly includes a magnetic head and a cantilever for supporting the magnetic head, the structure of which is described above.

[0026] Compared to existing technologies, because the write lines of this invention are configured in a layered structure distributed across different layers, the write impedance is reduced, thereby reducing signal transmission loss and improving write operation performance. Furthermore, since the lines are reconfigured in layers, a sufficiently wide frequency bandwidth can be obtained and maintained. Therefore, by employing this invention, not only can low impedance be achieved to reduce signal transmission loss, but a wider frequency bandwidth can also be obtained to improve write performance, ultimately improving write and read signal transmission.

[0027] The invention will become clearer from the following description, taken in conjunction with the accompanying drawings, which are used to explain embodiments of the invention. Attached Figure Description

[0028] Figure 1a This is a perspective view of a traditional disk drive unit.

[0029] Figure 1b This is a perspective view of a traditional HGA.

[0030] Figure 1cfor Figure 1b The image shown is a magnified view of a portion of the HGA.

[0031] Figure 1d for Figure 1b A partially enlarged view of the flexible component of the cantilever structure shown.

[0032] Figure 1e-1f For along Figure 1d A schematic diagram of the cross-section of the flexible component as shown by the AA and BB sections.

[0033] Figure 2 This is an exploded perspective view of one embodiment of the cantilever component of the present invention.

[0034] Figure 3 for Figure 2 A partial enlarged view of the flexible component of the cantilever shown.

[0035] Figures 4a-4b For along Figure 3 A schematic diagram of the cross-sections cut by the CC and DD sections.

[0036] Figure 5a This is a partial top view of the flexible component.

[0037] Figure 5b for Figure 5a The exploded diagram.

[0038] Figure 6a This is a comparison diagram of the write characteristic impedance of the layered structure write circuit in the prior art and the present invention.

[0039] Figure 6b This is a comparison diagram of the write bandwidth of the layered structure write circuit of the prior art and the present invention.

[0040] Figure 7a This is a comparison diagram of the characteristic impedances of the write and read lines of the layered structure of the present invention with those of the prior art.

[0041] Figure 7b This is a comparison diagram of the signal transmission loss of the write and read lines in the layered structure of the present invention with that of the prior art.

[0042] Figure 8 This is a perspective view of an embodiment of the HGA of the present invention.

[0043] Figure 9 This is a perspective view of an embodiment of the hard disk drive unit of the present invention. Detailed Implementation

[0044] Several different preferred embodiments of the present invention will now be described with reference to the accompanying drawings, wherein the same reference numerals in the different figures represent the same components. As described above, the essence of the present invention is to provide a cantilever assembly for a read / write head clasp assembly in a hard disk drive, the cantilever assembly including a flexible element having a multi-layer structure and a pair of write lines located in different layers, so as to reduce conductor impedance and signal transmission loss, while increasing bandwidth.

[0045] Figure 2 An embodiment of the cantilever component of the present invention is shown. For example... Figure 2 As shown, the cantilever component 290 includes a load bar 206, a base plate 208, a hinge 207, and a flexible component 205, all of which are assembled together.

[0046] refer to Figure 2 The load bar 206 transmits the load force to the flexible element 205 and the magnetic head mounted on the flexible element 205. The load bar 206 can be made of any material with suitable rigidity, such as stainless steel, to provide sufficient rigidity for transmitting the load force. The load bar 206 is connected to the substrate 208 via a hinge 207. A positioning hole 212 provided on the load bar 204 is used to align the load bar 206 and the flexible element 205. A protrusion 211 is formed on the load bar 206 to support the flexible element 205 at a position corresponding to the center of the magnetic head. Through the cooperation of this protrusion 211 and the flexible element 205, the load force is evenly transmitted to the magnetic head.

[0047] The substrate 208 is used to increase the rigidity of the entire cantilever 290, and it can be made of a rigid material such as stainless steel. A mounting hole 213 is formed at one end of the substrate 208, through which the cantilever 290 is mounted to the drive arm of the hard disk drive.

[0048] The hinge 207 has a mounting hole 210 at one end, which corresponds to the mounting hole 213 on the substrate 208. The hinge 207 is partially mounted onto the substrate 208, aligning the mounting holes 210 and 213 with each other. The hinge 207 and the substrate 208 can be laser-welded together, with the welding points distributed at the fine points 209 on the hinge 207. In addition, two pivot supports 214 extend from both sides of the hinge 207 to partially mount the hinge 207 onto the load bar 206.

[0049] like Figure 2 and Figure 3 As shown, the flexible element 205 passes through the hinge 207 and the load bar 206. The flexible element 205 has a front portion 211 and a tail portion 212 opposite to the front portion 211. A cantilevered tongue 213 is located at the front portion 211 of the flexible element 205 to support the magnetic head 203 (see reference). Figure 8 Multiple flexible circuits are disposed on the flexible element 205 along its length.

[0050] The focus of this invention is the layer structure of the flexible member 205. Cross-sectional views of the CC and DD positions at the front of the flexible member 205 are shown below. Figure 4a , 4b As shown. It should be noted that, for better visualization of the flexible circuit, Figure 3 The topmost cover layer of the flexible element shown is omitted, but... Figure 5a There is a display overlay.

[0051] like Figure 4a , 4b As shown, the flexible member 205 has a six-layer structure, which is stacked in the vertical direction (i.e., the thickness direction of the flexible member), including: a base metal layer 310 as the bottom layer, a base dielectric layer 320 formed on the base metal layer 310, a bottom conductive layer 330 formed on the base dielectric layer 320, a separating dielectric layer 340 formed on the bottom conductive layer 330, a top conductive layer 350 formed on the separating dielectric layer 340, and a cover layer 360 formed on the top conductive layer as the top layer.

[0052] Specifically, the base metal layer 310, as the bottom layer, is made of stainless steel to provide support. The bottom conductive layer 330 and the top conductive layer 350 serve as signal transmission layers, on which circuitry is formed; these layers are typically made of highly conductive metals such as copper. A separating dielectric layer 340, located between the bottom conductive layer 330 and the top conductive layer 350, separates the two conductive layers and is made of, for example, polyimide. The base dielectric layer 320 can also be made of polyimide. The capping layer 360 can be supported by a dielectric material, such as polyimide, to prevent oxidation of the signal transmission layers.

[0053] The circuitry of this invention is distributed in the top conductive layer 350 and the bottom conductive layer 330, respectively. (Combined with...) Figure 4a , 4b and Figure 5a , 5b Specifically, one of the write lines, 411, is disposed on the bottom conductive layer 330, and the other, 412, is disposed on the top conductive layer 350. Write lines 411 and 412 are connected via vias. One of the oscillator (OSC) lines, 421, is disposed on the bottom conductive layer 330, and the other, 422, is disposed on the top conductive layer 350. Oscillator lines 421 and 422 are connected via vias. A pair of read lines, 431 and 432, are both disposed on the top conductive layer 350. Additionally, a dynamic flight altitude (DFH) control line 441 is disposed on the top conductive layer 350 to control the dynamic flight altitude of the read / write head; a ground line 451 is disposed on the bottom conductive layer 350 and connected to the base metal layer 310 via a via for grounding. It is understood that the term "pair" as used herein refers to positive and negative signal lines.

[0054] Specifically, in some embodiments, the thicknesses of the base metal layer 310, base dielectric layer 320, bottom conductive layer 330, separator dielectric layer 340, top conductive layer 350, and capping layer 360 are variable to achieve predetermined impedance characteristics. Specifically, the widths of the write lines 411 and 412 are variable or fixed; preferably, the widths of the write lines 411 and 412 are fixed along the length of the flexible element. This uniform width helps improve impedance characteristics and reduce signal loss.

[0055] Figure 6a This diagram illustrates a comparison of the write characteristic impedance of the layered structure write circuits in the prior art and the present invention. The solid line 601 without circles represents the write characteristic impedance in the layered structure circuit of the present invention, while the solid line 602 with circles represents the write characteristic impedance in the prior art circuit. Taking a target impedance of 20 ohms as an example, both have the same target impedance of 20 ohms, but it can be seen that the target impedance curve of the prior art has a larger slope, while the target impedance curve of the present invention is flatter.

[0056] Figure 6b This section compares the write bandwidth of the layered structure write circuits of the prior art and the present invention. The solid line 611 without circles represents the signal transmission loss in the layered structure circuit of the present invention, while the solid line 612 with circles represents the signal transmission loss of the prior art circuit, expressed in dB as a function of frequency. It is evident that the present invention exhibits lower signal transmission loss.

[0057] Figure 7a This diagram compares the characteristic impedances of the write and read lines of the layered structure of the present invention with those of the prior art. Solid lines with squares represent the read characteristic impedance of the prior art, which is approximately 91 ohms; solid lines with circles represent the write characteristic impedance of the prior art, which is approximately 40 ohms. Dashed lines represent the read characteristic impedance of the present invention, which is approximately 100 ohms; solid lines represent the write characteristic impedance of the present invention, which is approximately 29 ohms. The layered circuitry of the present invention has a significantly flatter read time-domain reflectometry (TDR) curve and a longer write TDR curve than the prior art, which ultimately benefits signal transmission.

[0058] Figure 7b This diagram compares the signal transmission losses of the write and read circuits in the layered structure of the present invention with those of the prior art. Solid square lines represent the read signal transmission loss as a function of frequency in the prior art, in dB; solid lines with circles represent the write signal transmission loss in the prior art. Dashed lines represent the read signal transmission loss in dB in the present invention; solid lines represent the write signal transmission loss in the layered circuit of the present invention. The layered circuit of the present invention has lower signal transmission loss than the prior art. Furthermore, the read bandwidth of the present invention is 6 GHz wider than that of the prior art, and the write bandwidth of the present invention is approximately 2.7 GHz wider than that of the prior art.

[0059] As described above, compared to the prior art, because the write lines of the present invention are configured in a layered structure distributed across different layers, the write impedance is reduced, thereby reducing signal transmission loss and improving write operation performance. Furthermore, since the lines are reconfigured in layers, a sufficiently wide frequency bandwidth can be obtained and maintained. Therefore, by employing the present invention, not only can low impedance be obtained to reduce signal transmission loss, but a wider frequency bandwidth can also be achieved to improve write performance, ultimately improving write and read signal transmission.

[0060] Please refer to the following: Figure 8 One embodiment of the HGA 200 of the present invention includes a cantilever 290 and a magnetic head 203 supported by the cantilever 290. The cantilever 290 includes a load bar 206, a substrate 208, a hinge 207, and a flexible element 205, all assembled together. The hinge 207 has a mounting hole 210 for mounting the hinge 207 to the substrate 208. The magnetic head 203 is supported by the flexible element 205. As is known, the magnetic head 203 has terminals for connection to write elements and read elements (sensors), these terminals being connected to the contacts of the write and read elements. The write element can be a standard inductive magnetic write head, while the read element can be an MR element, GMR element, or TMR element with high read sensitivity.

[0061] Figure 9 This is one embodiment of the hard disk drive unit of the present invention. The hard disk drive 300 includes an HGA 200, a drive arm 304 connected to the HGA 200, a series of rotatable disks 301, and a spindle motor 301 that rotates the disks 301, all of which are assembled within a housing 309. As described above, the HGA 200 includes a cantilever 290 with a flexible element 205 and a read / write head 203. Similarly, the write lines of the flexible circuit 220 of the flexible element 205 are configured as described above to obtain the same advantages. Since the structure and assembly process of the hard disk drive are well known to those skilled in the art, a detailed description of its structure and assembly is omitted here.

[0062] In addition, this article also provides a method for forming a cantilever component, comprising: providing a flexible component having a layered structure, wherein forming the layered structure includes the following steps:

[0063] Forming a base metal layer as the bottom layer;

[0064] A base dielectric layer is formed on top of the base metal layer;

[0065] A bottom conductive layer is formed on top of the base dielectric layer;

[0066] A separating dielectric layer is formed on top of the bottom conductive layer;

[0067] A top conductive layer is formed on the separating dielectric layer; and

[0068] A capping layer is formed on top of the top conductive layer as the top layer.

[0069] In this invention, flexible circuits are formed on the bottom conductive layer and the top conductive layer according to the structural configuration described in the above embodiment. Specifically, one of the write lines is located on the bottom conductive layer, and the other on the top conductive layer, connected by vias. Similarly, one of the oscillator lines is located on the bottom conductive layer, and the other on the top conductive layer, connected by vias. Both read lines are located on the top conductive layer. Additionally, a dynamic flight altitude control line is located on the top conductive layer to control the dynamic flight altitude of the magnetic head; a grounding line is located on the bottom conductive layer and connected to the base metal layer vias to achieve grounding. The cantilever component formed by this invention also possesses the advantages mentioned above, which will not be elaborated upon here.

[0070] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A cantilever assembly for magnetic head flaps, comprising a flexible element having a layered structure, characterized in that, The layered structure includes: As the underlying base metal layer; A base dielectric layer formed on top of the base metal layer; A bottom conductive layer formed on top of the base dielectric layer; A separating dielectric layer formed on top of the bottom conductive layer; A top conductive layer formed on the separating dielectric layer, wherein one of a pair of write lines is disposed on the bottom conductive layer, and the other of the pair of write lines is disposed on the top conductive layer; and A capping layer is formed on top of the top conductive layer as the top layer; The write lines located on the top conductive layer and the bottom conductive layer are connected through vias.

2. The cantilever component as described in claim 1, characterized in that: A pair of oscillator circuits are also provided on the top conductive layer and the bottom conductive layer, respectively.

3. The cantilever component as described in claim 2, characterized in that: The top conductive layer is provided with a pair of reading lines and a dynamic flight altitude control line; the bottom conductive layer is provided with a grounding line.

4. The cantilever component as described in claim 3, characterized in that: Each line forms a corresponding contact point at the front of the flexible element to connect with the magnetic head of the magnetic head assembly.

5. The cantilever component as described in claim 2, characterized in that: The oscillator circuitry located on the top conductive layer and the bottom conductive layer is connected via vias.

6. The cantilever component as described in claim 3, characterized in that: The grounding line is connected to the base metal layer through a through-hole.

7. The cantilever component as described in claim 1, characterized in that: The base dielectric layer and the separating dielectric layer are made of polyimide, and the base metal layer is made of stainless steel.

8. The cantilever component as described in claim 1, characterized in that: Each layer in the layered structure is stacked vertically.

9. A magnetic head flap assembly, comprising: A magnetic head and a cantilever for supporting the magnetic head; the cantilever includes the components as described in any one of claims 1-8.

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