Terminal connection portion of electronic device

Abstract

A first terminal (31) provided on the tail pad portion (20) includes a base portion (32), a bent portion (33), and an overlapping portion (34). The base portion (32) includes a first surface (32a) fixed to the base insulating layer (23) and a second surface (32b) on the opposite side from the first surface (32a). The bent portion (33) is reversed in the thickness direction of the base portion (32) from an end portion (32c) of the base portion (32) toward the second surface (32b). The overlapping portion (34) extends from the bent portion (33) in the direction of the second surface (32b). An anisotropic conductive film (ACF) (41) is provided between the overlapping portion (34) and a second terminal (42). The overlapping portion (34) and the second terminal (42) are connected to each other by the ACF (41).

Description

Technical Field

[0001] The present invention relates to a terminal connection portion that connects a first terminal and a second terminal of an electronic device, and is applicable, for example, to a hard disk drive. Background Technology

[0002] Hard disk drives (hereinafter referred to as disk drives) are used in information processing devices such as personal computers. A disk drive includes a disk that can rotate about a spindle, a carriage that can rotate about a pivot, etc. The carriage includes multiple arms that rotate about a pivot via positioning motors.

[0003] Each arm is equipped with a disk drive suspension (hereinafter referred to as "suspension"). The suspension includes a load beam, a flexure along the load beam, etc. A slider is installed near the distal end of the flexure. The slider contains elements for accessing data such as reading data recorded on the disk and writing data.

[0004] The flexible component comprises a metal base (metal substrate), a base insulation layer, multiple conductors, a cover layer, etc. The metal base is made of a thin stainless steel sheet. The base insulation layer is formed on the metal base. Conductors are formed on the base insulation layer. The cover layer covers the conductors. One end of each conductor connects to the sliding element and various functional components. The other end of each conductor connects to electronic equipment such as a preamplifier via a terminal connection. The base insulation layer and the cover layer are made of an electrically insulating resin such as polyimide. The base insulation layer, conductors, cover layer, etc., constitute the wiring section.

[0005] Examples of flexural members are disclosed in JP 2015-219940 A (Patent Document 1) or US 8,467,153 B1 (Patent Document 2). The flexural member includes a flexural member body disposed along a load beam and a flexural member tail extending behind the load beam. A tail pad is formed at the end of the flexural member tail.

[0006] The tail pad section contains multiple terminals (also called tail terminals). These tail terminals are formed by integrating with the conductor at its end. The tail terminals are electrically connected to the terminals of electronic devices or flexible circuit boards via connecting conductive elements. These connecting conductive elements are anisotropic conductive film (ACF), solder layers, etc. ACF is an abbreviation for anisotropic conductive film. An example of an electronic device is a preamplifier. In this specification, the terminals of a flexible circuit board may also be referred to as board terminals.

[0007] When connecting the tail terminal and the board terminal to each other via the ACF, the ACF is placed between the tail terminal and the board terminal. While maintaining this state, the ACF is pressurized and heated. Thus, the tail terminal and the board terminal are electrically connected to each other through the ACF between them, and are thus secured to each other. When using solder layer connections, heating is performed under a certain pressure.

[0008] To increase the amount of data to be recorded on disk drives, there is a trend towards increasing the number of disks built into them. Consistent with this trend, the number of suspensions used in disk drives is also increasing. Furthermore, as suspension functions become more numerous, the number of conductors in the wiring section of the flexible components is also increasing. Consequently, the number of tail terminals to be placed in the tail pad section is increasing. However, due to the limited space inside the disk drive, the size of the tail terminals must decrease as the number of tail terminals increases. Moreover, a large number of tail terminals must be densely arranged in the tail pad section.

[0009] The tail terminals are formed to integrate with the corresponding conductor at the end of each conductor. The height of the tail terminals in the thickness direction is the same as the height of the conductors in the thickness direction. Since the tail terminals are not covered by a capping layer, their surfaces are exposed. Conversely, the conductors are covered by the capping layer. Due to this construction, when a conductive material such as ACF is placed between the tail terminals and the board terminals and pressure is applied to them, the pressure may vary or may be insufficient. Insufficient pressure may lead to incorrect connection between the tail terminals and the board terminals.

[0010] In the terminal connection section described in Patent Document 1, the ACF is placed between the tail terminal and the board terminal, and is pressurized and heated by a clamp. However, since the thickness of the tail terminal is the same as the thickness of the conductor, and the conductor is covered by a cover layer, the clamping force may change or be insufficient when the ACF is clamped by the clamp.

[0011] In the terminal connection portion described in Patent Document 2, a portion of the base insulation layer (where the tail terminal is located) includes a support portion formed therein, the thickness of which is slightly thicker than other components. Note that a special manufacturing process is required to form portions of different thicknesses (thick and thin portions) on a portion of the base insulation layer.

[0012] The object of the present invention is to provide a terminal connection portion that connects the tail terminal (first terminal) and the board terminal (second terminal) of a flexure member of a disk drive suspension to each other via a connecting conductive member such as an ACF. Summary of the Invention

[0013] According to one embodiment, the terminal connection portion includes a first terminal of the wiring portion and a second terminal disposed on the opposite side of the first terminal. The wiring portion includes a base insulation layer, a conductor formed on the base insulation layer, a cover layer covering the conductor, and a first terminal formed at the end of the conductor. The first terminal is integrally formed with the conductor. Both the first terminal and the second terminal are mainly made of copper, and are plated with gold or the like as needed.

[0014] The first terminal includes a base, a bent portion, and an overlapping portion. The base includes a first surface and a second surface located opposite the first surface. The first surface is disposed along and fixed to the base insulating layer. The bent portion extends from the end of the base toward the second surface in the reverse direction of the base thickness. The overlapping portion extends from the bent portion along the direction of the second surface. A connecting conductive element is disposed between the overlapping portion and the second terminal. The connecting conductive element fixes the overlapping portion to the second terminal and electrically connects them to each other. An example of the connecting conductive element is an anisotropic conductive film (ACF). The connecting conductive element may be a solder layer.

[0015] According to one embodiment of the present invention, for example, the tail terminal (first terminal) located at the tail pad of the flexure and the terminal (second terminal) of the circuit board can be reliably connected by a connecting conductive element such as ACF.

[0016] For example, the first terminal is a tail terminal located at the tail pad of the flexible component. The second terminal is a board terminal located on a circuit board. The tail pad may have an opening, and multiple first terminals may be located on the inner edge of the opening. The first and third terminals may be located within the tail pad. The height of the third terminal along the thickness direction is less than the height of the first terminal along the thickness direction.

[0017] A resin insulating portion, as part of a cover layer, may be provided between the second surface of the first terminal and the overlapping portion. The first terminal may include an extension. The extension extends from the overlapping portion along the cover layer direction and overlaps the cover layer. A conductor electrically insulated from the first terminal may be provided between the extension and the base insulating layer inside the cover layer.

[0018] Other objects and advantages of the invention will be set forth in the following description, and some of these other objects and advantages will become apparent from the following description, or may be learned by practicing the invention. The objects and advantages of the invention are achieved and obtained by the means and combinations particularly pointed out below. Attached Figure Description

[0019] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the invention and, together with the above-described invention and the detailed description below, explain the principles of the invention.

[0020] Figure 1 This is a plan view of the suspension including the tail pad portion according to the first embodiment.

[0021] Figure 2 It is shown schematically. Figure 1 The diagram shows a partial plan view of the rear bracing pad of the suspension.

[0022] Figure 3 It is along Figure 2A cross-sectional view of the tail pad taken by line F3-F3 in the diagram.

[0023] Figure 4 Before bending the first terminal Figure 2 The diagram shows the state of the tail pad section.

[0024] Figure 5 It is along Figure 4 A cross-sectional view of the tail pad portion taken by line F5-F5 in the diagram.

[0025] Figure 6 It is shown schematically. Figure 3 The diagram shows a cross-sectional view of the first terminal connected to the second terminal via an ACF.

[0026] Figure 7 It shows Figure 1 The diagram shows a plan view of the rear pad portion and circuit board of the suspension.

[0027] Figure 8 This is a schematic cross-sectional view illustrating an example of a disk drive.

[0028] Figure 9 This is a partial cross-sectional view showing the tail pad portion of the second embodiment.

[0029] Figure 10 This is a partial cross-sectional view showing the tail pad portion of the third embodiment.

[0030] Figure 11 This is a partial plan view of the tail portion of the flexural member, including the tail pad portion, according to the fourth embodiment.

[0031] Figure 12 This is a plan view of the tail pad portion according to the fifth embodiment.

[0032] Figure 13 It is along Figure 12 A cross-sectional view of the tail pad portion taken from line F13-F13 in the diagram.

[0033] Figure 14 This shows a partial plan view of the tail pad portion according to the sixth embodiment.

[0034] Figure 15 It is along Figure 14 A cross-sectional view of the tail pad portion taken from line F15-F15 in the diagram. Detailed Implementation

[0035] [First Embodiment]

[0036] Now refer to Figures 1 to 7 The terminal connection portion of the tail pad portion according to the first embodiment is described.

[0037] Figure 1 This is a plan view showing an example of a suspension 10 for a hard disk drive. The suspension 10 includes a base plate 11, a load beam 12, a flexure 13, a slider 15, etc. The slider 15 is disposed on the tongue 14 of the flexure 13.

[0038] The flexural member 13 includes a flexural member body 16 and a flexural member tail 17. The flexural member body 16 is fixed to the load beam 12. The flexural member tail 17 (along...) Figure 1 The direction indicated by R1 extends from the body of the flexure 16 to the rear side of the base plate 11. A tail pad portion 20 is formed at the end of the tail portion 17 of the flexure.

[0039] The load beam 12 is made of stainless steel plate and extends along the length of the suspension 10. Figure 1 The direction indicated by the double-headed arrow X1 is the longitudinal direction of the load beam 12, that is, the longitudinal direction of the suspension 10. The thickness of the load beam 12 is, for example, 20 to 40 μm, but it can also be other thicknesses.

[0040] Figure 2 This is a schematic partial plan view of the tail pad portion 20. Figure 3 It is along Figure 2 The image shows a cross-sectional view of the tail pad portion 20 taken along line F3-F3. The tail pad portion 20 includes a metal base (metal substrate) 21 and a wiring portion 22. The metal base 21 is made of a thin sheet of stainless steel. The wiring portion 22 is disposed along the metal base 21. An example of the thickness of the metal base 21 is 20 μm (12 to 25 μm), which is less than the thickness of the load beam 12.

[0041] like Figure 2 and Figure 3 As shown, the wiring portion 22 includes a base insulation layer 23, a conductor group 24, and a cover layer 25. The base insulation layer 23 is made of an electrically insulating resin, such as polyimide. The conductor group 24 includes a plurality of conductors 24a, 24b, 24c, and 24d (only some are shown). Conductors 24a, 24b, 24c, and 24d are formed on the base insulation layer 23. The cover layer 25 is made of an electrically insulating resin such as polyimide and covers the conductor group 24.

[0042] An opening 30 is formed in the tail pad portion 20. For example... Figure 3 As shown, the opening 30 includes a first opening 30a formed in the metal base 21 and a second opening 30b formed in the base insulating layer 23. The openings 30a and 30b are open in the thickness direction of the tail pad portion 20.

[0043] In the opening 30, inner edges 30c and 30d face each other. Multiple first terminals (tail terminals) 31 are provided on the inner edges 30c and 30d. The first terminals 31 are formed by integrating with the corresponding conductor at the end of each conductor using copper (e.g., copper plating) shared with the conductor. Conductors 24a-24d are each covered by a cover layer 25. On the other hand, the first terminals 31 are not covered by the cover layer 25. Therefore, the surface of the first terminals 31 is exposed.

[0044] like Figure 3 As shown, each first terminal 31 includes a base 32, a bend 33, and an overlap 34. The base 32 is fixed to the base insulating layer 23 along the base insulating layer 23 itself. The base 32 has a first surface 32a along the base insulating layer 23 and a second surface 32b opposite to the first surface 32a. Figure 3 The direction pointed to by the double-headed arrow A1 is the thickness direction of the first terminal 31.

[0045] The bent portion 33 has a shape that reverses 180° in the thickness direction from the end 32c of the base 32 toward the second surface 32b. That is, the bent portion 33... Figure 3 It is U-shaped in the horizontal direction. For example... Figure 3 As shown, the side surface 36 of the base insulating layer 23 protrudes by a length L1 relative to the side surface 35 inside the opening 30 of the metal base 21. Furthermore, the end face 33a of the bent portion 33 protrudes by a length L2 relative to the side surface 36 of the base insulating layer 23. An insulating distance L3 (L1+L2) is defined between the side surface 35 of the metal base 21 and the end face 33a of the first terminal 31, thereby enhancing electrical insulation.

[0046] The overlapping portion 34 extends from the curved portion 33 in the direction along the second surface 32b. Furthermore, the overlapping portion 34 overlaps with the second surface 32b of the base 32. With this structure, the first terminal 31 extends along the thickness direction (e.g., ...). Figure 3 The height H1 (as shown) is approximately twice the height H2 of conductor 24a.

[0047] Figure 4 This is a plan view of the tail pad portion 20 having terminal member 31a before the bending portion 33 and the overlapping portion 34 are formed. Figure 5 It is along Figure 4 A cross-sectional view of the tail pad portion 20, taken from line F5-F5. (See attached image.) Figure 4 and Figure 5 As shown, a flat terminal member 31a is formed on the edge portions 30c and 30d of the opening 30 of the tail pad portion 20. The terminal member 31a is formed by a manufacturing process such as electroplating or etching.

[0048] Terminal member 31a along the thickness direction ( Figure 5 Arrow A2 indicates the middle section M1 in the vertical direction. Figure 4 The single-dotted line in the diagram indicates the bend. Therefore, including... Figure 2 and 3 The first terminal 31 of the curved portion 33 and the overlapping portion 34 shown in the figure is formed.

[0049] Figure 6 This is a cross-sectional view of the terminal connection portion 40 including the first terminal 31. The terminal connection portion 40 includes the first terminal 31, an anisotropic conductive film (ACF) 41 serving as a connecting conductive element, and a second terminal 42 for connecting components. The first terminal 31 and the second terminal 42 are connected to each other via the ACF 41. Both the first terminal 31 and the second terminal 42 are primarily made of copper and have a coating, such as gold plating, applied to their surfaces as needed.

[0050] Figure 7 A portion of the tail pad portion 20 and the circuit board 50 in this embodiment are shown. On the circuit board 50, second terminals 42 are respectively disposed at positions corresponding to the first terminals 31. Electronic components, including preamplifiers for signal processing, are mounted on the circuit board 50. Conductors 51 disposed on the circuit board 50 are electrically connected to the second terminals 42.

[0051] Reference Figure 6 An ACF 41 is disposed between the first terminal 31 and the second terminal 42. The ACF 41 comprises a thermosetting base resin 41a and a plurality of conductive particles 41b mixed into the base resin 41a. The particle size of the conductive particles 41b is very small, for example, from a few micrometers (μm) to tens of micrometers (μm). However, in Figure 6 In the diagram, for ease of explanation, the conductive particle 41b is shown as larger.

[0052] The ACF 41, positioned between the first terminal 31 and the second terminal 42, is pressurized and heated by the clamp 60. This causes the conductive particles 41b located between the first terminal 31 and the second terminal 42 to undergo dielectric breakdown, thereby achieving conductivity between the first terminal 31 and the second terminal 42. Then, as the temperature decreases, the base resin 41a hardens. Thus, the first terminal 31 and the second terminal 42 are electrically connected to each other and also mechanically fixed to each other via the ACF 41.

[0053] In this embodiment, the first terminal 31 includes an overlapping portion 34 that overlaps with the base 32. For example... Figure 3 As shown, the height H1 of the first terminal 31 along the thickness direction is greater than the height H3 of the covering layer 25 covering conductors 24a and 24b. Figure 6As shown, an ACF 41 is provided between the first terminal 31 and the second terminal 42. The ACF 41 is pressurized between the first terminal 31 and the second terminal 42. During the pressurization process, conductors 24a and 24b and the covering layer 25 do not interfere with the pressurization of the ACF 41, allowing for reliable pressurization and heating of the ACF 41. Therefore, the first terminal 31 and the second terminal 42 can be reliably connected to each other via the ACF 41.

[0054] Figure 8 This is a schematic cross-sectional view illustrating an example of a disk drive 70. The disk drive 70 includes a housing 71 (only a portion is shown), a disk 72, a bracket 74, and a positioning motor 75. The disk 72 rotates about a spindle. The bracket 74 pivots about a pivot 73. The motor 75 drives the bracket 74. The housing 71 is sealed by a cover. A suspension 10 is attached to the distal end of each of a plurality of arms 76 of the bracket 74.

[0055] When the disk 72 rotates at high speed, an air bearing is formed between the slider 15 and each disk 72. When the positioning motor 75 drives the bracket 74 to rotate, the suspension 10 moves radially along the disk 72. Through this operation, the slider 15 is moved to the desired position on the disk 72.

[0056] [Second Embodiment]

[0057] Figure 9 This is a partial cross-sectional view showing the tail pad portion 20A having a terminal connection portion 40A according to the second embodiment. A resin isolation portion 80 is provided between the base 32 and the overlapping portion 34 of the first terminal 31 of the tail pad portion 20A. The resin isolation portion 80 is part of the cover layer 25, and like the cover layer 25, it is also made of an electrically insulating resin such as polyimide.

[0058] like Figure 9 As shown, the terminal connection portion 40A of this embodiment includes a resin isolation portion 80. The resin isolation portion 80 is disposed between the base portion 32 and the overlapping portion 34 of the first terminal 31. Therefore, the height H4 of the first terminal 31 from the base insulating layer 23 can be greater than the height H1 of the first terminal 31 in the first embodiment (e.g., ...). Figure 3 (As shown). Regarding other configurations and operations, the tail pad portion 20A of the second embodiment is similar to the tail pad portion 20 of the first embodiment (as shown). Figures 1 to 7 Therefore, common structural elements are represented by common symbols, and their explanations will be omitted.

[0059] [Third Embodiment]

[0060] Figure 10A tail pad portion 20B with a terminal connection portion 40B according to a third embodiment is shown. The first terminal 31 of the tail pad portion 20B includes a base 32, a bend 33, an overlap 34, and an extension 90. The base 32 is fixed to a base insulating layer 23. The extension 90 extends from the overlap 34 along the direction of the cover layer 25 and overlaps with the cover layer 25. Regarding other configurations and operations, the tail pad portion 20B of the third embodiment is similar to the tail pad portion 20 of the first embodiment. Figures 1 to 7 Therefore, common structural elements are represented by common symbols, and their explanations will be omitted.

[0061] [Fourth Embodiment]

[0062] Figure 11 A portion of a flexible tail portion 17 having a tail pad portion 20C according to a fourth embodiment is shown. One side of a plurality of first terminals 31 disposed in the tail pad portion 20C is provided along one side 91 of the tail pad portion 20C. The other side of the first terminals 31 may be disposed on another side 92 of the tail pad portion 20C. Regarding other configurations and operations, the tail pad portion 20C of the fourth embodiment is similar to the tail pad portion 20 of the first embodiment. Figures 1 to 7 Therefore, common structural elements are represented by common symbols, and their explanations will be omitted.

[0063] [Fifth Embodiment]

[0064] Figure 12 This is a plan view showing the tail pad portion 20D according to the fifth embodiment. Figure 13 It is along Figure 12 The image shows a cross-sectional view of the tail pad portion 20D taken along line F13-F13. The tail pad portion 20D includes a conductor 24b disposed within the cover layer 25. The conductor 24b is located within the cover layer 25, between the extension 90 of the first terminal 31 and the base insulating layer 23. Therefore, the conductor 24b is electrically insulated from the first terminal 31.

[0065] exist Figure 12 In the plan view of the tail pad portion 20D shown, there is a portion 95 where the first terminal 31 and the conductor 24b intersect each other. Even with the intersection portion 95, a short circuit between the first terminal 31 and the conductor 24b can be avoided. With the tail pad portion 20D having the above-described structure, the width W1 of the tail pad portion 20D can be reduced compared to the case where the conductor 24b bypasses the outside of the first terminal 31. Therefore, in the case of a disk drive with a large number of disks, it is easier to leave space for arranging multiple tail pad portions 20D side by side, which is advantageous.

[0066] [Sixth Embodiment]

[0067] Figure 14The tail pad portion 20E according to the sixth embodiment is shown. Figure 15 It is along Figure 14 The image shows a cross-sectional view of the tail pad portion 20E, taken along line F15-F15. The tail pad portion 20E includes a first terminal 31 with an overlap 34 and a flat third terminal 100 without the overlap 34. The height H5 of the third terminal 100 (as shown in the image) Figure 15 The height H1 of the first terminal 31 is less than (lower than) that of the third terminal 100. By providing the first terminal 31 and the third terminal 100 with different heights on the tail pad portion 20E, it is possible to accommodate multiple second terminals with two different heights. Both the first terminal 31 and the third terminal 100 can be made primarily of copper, and gold plating or other coatings can be applied to their surfaces as needed.

[0068] Needless to say, when implementing this invention, the specific configuration of the suspension, circuit board, etc., as examples of electronic devices, as well as the shape and position of the first and second terminals, can be changed in various ways. Furthermore, the technical concept of this invention can also be applied to terminal connection portions of electronic devices other than disk drives.

[0069] Other advantages and modifications will readily occur to those skilled in the art. Therefore, the invention is broadly defined and not limited to the specific details and representative embodiments shown and described herein. Consequently, various modifications can be made without departing from the spirit or scope of the overall inventive concept as defined by the appended claims and their equivalents.

Claims

1. A terminal connection portion for an electronic device, comprising a first terminal (31) of a wiring portion (22) and a second terminal (42) configured to be opposite to the first terminal (31). The wiring section (22) includes: A base insulating layer (23); Conductors (24a), (24b), (24c) and (24d) are formed on the base insulating layer (23); A cover layer (25) covers the conductors (24a), (24b), (24c), and (24d); and The first terminal (31) is formed at the end of each of the conductors (24a), (24b), (24c) and (24d) and integrated with each of the conductors (24a), (24b), (24c) and (24d), and The first terminal (31) is characterized by including: A base (32) includes a first surface (32a) fixed to the base insulation layer (23) along the base insulation layer (23) and a second surface (32b) on the opposite side of the first surface (32a). A curved portion (33) is reversed from one end of the base (32) toward the second surface (32b) along the thickness direction of the base (32); An overlapping portion (34) extends from the curved portion (33) along the direction of the second surface (32b); and A conductive connector is disposed between the overlapping portion (34) and the second terminal (42) for fixing and electrically connecting the overlapping portion (34) and the second terminal (42); The height (H1) of the first terminal (31) along the thickness direction is greater than the height (H3) of the cover layer (25).

2. The terminal connection portion according to claim 1, characterized in that, The connecting conductive element is an anisotropic conductive film (41).

3. The terminal connection portion according to claim 1, characterized in that, The first terminal (31) is a tail terminal, which is disposed on each of the tail pad portions (20), (20A), (20B), (20C), (20D) and (20E) of the flexure (13) of the disk drive suspension (10), and The second terminal (42) is a board terminal disposed on the circuit board (50).

4. The terminal connection portion according to claim 3, characterized in that, The tail pad portions (20), (20A), (20B), (20D), and (20E) each include an opening (30), and Multiple first terminals (31) are disposed on the edge portion inside the opening (30).

5. The terminal connection portion according to claim 3, characterized in that, The first terminal (31) and the third terminal (100) are disposed on the tail pad portion (20E), wherein the height of the third terminal in the thickness direction is less than the height of the first terminal (31) in the thickness direction.

6. The terminal connection portion according to claim 1, characterized in that, It also includes a resin isolation portion (80), which is part of the cover layer (25) between the second surface (32b) of the first terminal (31) and the overlapping portion (34).

7. The terminal connection portion according to claim 1, characterized in that, The first terminal (31) includes an extension (90) that extends from the overlapping portion (34) along the direction of the cover layer (25) to overlap with the cover layer (25).

8. The terminal connection portion according to claim 1, characterized in that, The first terminal (31) includes an extension (90) that extends from the overlapping portion (34) along the direction of the cover layer (25) to overlap with the cover layer (125), and A conductor (24b) electrically insulated from the first terminal (31) is disposed between the extension (90) and the base insulation layer (23) inside the cover layer (25).

Images