Suspension for disk drive, electronic component, and method of connecting suspension and electronic component

Abstract

A suspension for a magnetic disk device according to an embodiment includes a load beam, a flexure overlapping the load beam, a first end tab provided to the flexure, and a first bump provided to an upper surface of the first end tab. The first end tab includes a narrow-width portion having a first width in a first direction and including a center of the first end tab, and a wide-width portion having a second width greater than the first width in the first direction and juxtaposed with the narrow-width portion in a second direction intersecting the first direction. The first bump has a first height from a lower surface of the first end tab at the center. The first height is greater than the first width.

Description

Technical Field

[0001] The present invention relates to a suspension for a disk drive in a hard disk drive, electronic components mounted in the suspension, and a method for connecting the suspension to the electronic components. Background Technology

[0002] Hard disk drives (HDDs) are commonly used in information processing devices such as personal computers. A typical HDD consists of a disk that rotates around a spindle and a support that rotates around a pivot. The support usually has an actuator arm that can rotate laterally along the disk tracks around the pivot using a positioning motor such as a voice coil motor.

[0003] The actuator arm is equipped with a suspension for the disk drive (hereinafter referred to as the suspension). The suspension generally includes a load-bearing beam and a flexible member overlapping the load-bearing beam. A slider constituting the read / write head is provided on a universal joint formed near the front end of the flexible member. The slider is provided with elements (sensors) for reading or writing data.

[0004] The flexure has multiple wirings. These wirings connect to terminals (pads) located at the front end and the rear end of the suspension. The terminals at the front end are soldered to the terminals on the slider. The terminals at the rear end are soldered to the flexible printed circuit board (FPC).

[0005] Well-known methods for connecting terminals by soldering include those described in Japanese Patent Application Publication Nos. 7-320434 and 11-110925. The methods described in these documents involve first forming solder bumps on the terminals, flattening the solder bumps, bringing them close to the terminals to be connected, and then melting the bumps to make them contact the terminals. Flattening the bumps can improve the alignment tolerance between the terminals.

[0006] In recent years, as suspension systems have become increasingly sophisticated, the number of wiring and terminals on the flexural components has also increased. This results in smaller spacing between terminals, potentially leading to short circuits between adjacent bumps on the terminals.

[0007] To address this issue, one method is to reduce the amount of solder forming the bump. However, this may lead to poor contact between the terminals.

[0008] Furthermore, Utility Model Publication No. 5-67048 and Japanese Patent Publication No. 2013-33570 disclose methods for reducing the central width of a terminal to reduce the height and width of the central portion of a bump. However, if the height of the bump is reduced, it may be difficult to smoothly engage the bump with the bump to be connected when the bump is flattened as described above and then melted. Moreover, since the height difference before and after the bump is flattened is smaller, the allowable alignment error between the terminals may be reduced. Summary of the Invention

[0009] The problem to be solved by the present invention

[0010] As described above, there are many areas where the connection between suspension terminals and terminals of electronic components such as sliders or flexible circuit boards can be improved. Therefore, the present invention provides a suspension, electronic components, and a method for connecting the suspension and electronic components to achieve better connection between terminals.

[0011] Methods for solving problems

[0012] According to an embodiment of the present invention, a suspension for a disk drive includes a support beam, a flexural portion overlapping the support beam, a first terminal provided in the flexural portion, and a first protrusion provided on the upper surface of the first terminal. The first terminal has a first width in a first direction, and has a narrow width portion including the center of the first terminal, a second width larger than the first width in the first direction, and a wide width portion parallel to the narrow width portion in a second direction intersecting the first direction. The first protrusion has a first height at its center, based on the lower surface of the first terminal. The first height is larger than the first width.

[0013] According to one embodiment of the present invention, a connection method electrically connects a suspension for a disk drive and an electronic component having a second bump having a second terminal on the upper surface of the second terminal. The method includes steps of flattening the first bump, bringing the first bump and the second bump closer together and intersecting a first plane including the upper surface of the first terminal and a second plane including the upper surface of the second terminal to align the suspension and the electronic component, and connecting the first bump and the second bump by melting them.

[0014] According to one embodiment of the present invention, the electronic component is electrically connected to a disk drive via a suspension. The electronic component includes a second terminal and a second protrusion disposed on the upper surface of the second terminal. The second terminal has a first width in a first direction, and has a narrow width portion including the center of the second terminal, a second width larger than the first width in the first direction, and a wide width portion in a second direction intersecting the first direction, parallel to the narrow width portion. The second protrusion has a first height at its center, based on the lower surface of the second terminal. The first height is larger than the first width.

[0015] According to one embodiment of the present invention, a connection method electrically connects a disk drive suspension having a first terminal and a first bump disposed on the upper surface of the first terminal, and the electronic component, comprising the steps of flattening the second bump, bringing the first bump and the second bump closer together and intersecting a first plane including the upper surface of the first terminal and a second plane including the upper surface of the second terminal to align the suspension and the electronic component, and connecting the first bump and the second bump by melting them.

[0016] Invention Effects

[0017] This invention provides a suspension, electronic components, and a method for connecting the suspension and electronic components, which enables better connection of terminals. Attached Figure Description

[0018] Figure 1 This is a simplified side view of a disk drive.

[0019] Figure 2 A partial, simplified cross-sectional view of the disk device.

[0020] Figure 3 A simplified plan view of a magnetic head universal joint assembly with suspension and slider.

[0021] Figure 4 A simplified side view illustrating an example of the connection structure between the suspension and the flexible circuit board.

[0022] Figure 5 A simplified side view illustrating an example of the connection structure between the suspension and the slider.

[0023] Figure 6 A simplified plan view is provided to illustrate an example of a terminal according to the first embodiment.

[0024] Figure 7 A simplified plan view of the enlarged terminals.

[0025] Figure 8 For along Figure 7 A simplified cross-sectional view between the terminals and bumps of line VIII-VIII.

[0026] Figure 9 For along Figure 7 A simplified cross-sectional view between the terminal (narrow width) and the bump of the IX-IX line.

[0027] Figure 10 This is an example flowchart illustrating a connection method between the suspension and electronic components.

[0028] Figure 11A simplified cross-sectional view is shown between the terminal and the flattened bump.

[0029] Figure 12 A simplified cross-sectional view of the aligned suspension and flexible circuit board.

[0030] Figure 13 A simplified cross-sectional view showing the state of the integrated bump after melting and cooling and solidification.

[0031] Figure 14 A table showing the implementation forms and comparative examples of terminals and bumps.

[0032] Figure 15 This is a simplified plan view of the terminal according to the first modified example.

[0033] Figure 16 This is a simplified plan view of the terminal according to the second modification.

[0034] Figure 17 This is a simplified plan view of the terminal according to the third modification.

[0035] Figure 18 A simplified cross-sectional view is provided to illustrate other structures that can be applied to the terminals.

[0036] Symbol explanation:

[0037] 1···Disk drive, 10···Suspension, 11···Flexible circuit board, 12···Slider, 31, 32, 41, 42···Terminals, 33, 43···Connecting parts, 33A, 33B, 43A, 43B···Protrusions, R···Recess. Detailed Implementation

[0038] Implementation Form 1

[0039] The following is for reference Figures 1 to 4 The first implementation form will be described.

[0040] (Disk device)

[0041] Figure 1 This is a simplified side view of an example of a hard disk drive (HDD) 1. The HDD 1 includes a housing 2, multiple disks 4 rotating about a spindle 3, a support 6 rotatable about a pivot 5, a positioning motor (voice coil motor) 7 for driving the support 6, and a connector 8. The housing 2 is sealed by a cover shown in the illustration. The connector 8 is connected to a control panel shown in the illustration.

[0042] Figure 2 This is a partial, simplified cross-sectional view of disk device 1. Figure 1 and Figure 2As shown, multiple arms 6a (support arms) are provided on the bracket 6. A slider 12 constituting a read / write head is provided at the front end of each suspension 10. The slider 12 can write data to and read data from the disk 4. When the disk 4 rotates at high speed, an air bearing is formed between the disk 4 and the slider 12 due to airflow.

[0043] When the bracket 6 is rotated by the positioning motor 7, the suspension 10 moves in the diametrical direction of the disk 4, thereby allowing the slider to move to the desired track on the disk 4.

[0044] (Suspension)

[0045] Figure 3 A simplified plan view is provided to illustrate an example of a magnetic head universal joint assembly including a suspension 10 and a slider 12. The suspension 10 includes a base plate 15, a support beam 16, and a flexure portion 20. The base plate 15 has a boss portion 15a. The boss portion 15a is fixed to... Figure 1 and Figure 2 The arm 6a of the bracket 6 shown.

[0046] The load-bearing beam 16 and the flexure portion 20 are rectangular in the suspension 10, with the longer side extending in the length direction X. The load-bearing beam 16 is made of, for example, stainless steel sheet. The flexure portion 20 has a front end portion 21 that overlaps with the load-bearing beam 16, and a tail portion 22 that extends from the front end portion 21 toward the rear of the base plate 15 (lower in the figure).

[0047] The tail portion 22 has a pad portion 23 at its end. The pad portion 23 is connected to one end of the flexible circuit board 11. The other end of the flexible circuit board 11 is connected to... Figure 1 Connector 8 is shown. A pivotable latch 24 is formed on the front end 21, which functions as a universal joint.

[0048] Figure 4 A simplified side view illustrating an example of the connection structure between the suspension 10 and the flexible circuit board 11 is shown. The flexure 20 has, for example, a base metal and an insulating layer covering the entire surface of the base metal. Furthermore, the flexure 20 has a plurality of wirings 30 formed on the insulating layer and a plurality of terminals 31 respectively connected to these wirings.

[0049] Multiple terminals 31 are formed on one side surface 23a of the tail portion 22 and are arranged side by side at intervals in a direction slightly parallel to the length direction X.

[0050] The flexible circuit board 11 has a plurality of terminals 32 disposed on one side surface 11a. Surface 11a intersects surface 23a at a specified angle. Figure 4 In the example, surface 11a intersects surface 23a at a right angle. Each terminal 32 is connected to a plurality of wirings 34 disposed on the flexible circuit board 11.

[0051] Multiple terminals 32 are arranged at intervals in a direction, for example, slightly parallel to the length direction X. Each terminal 32 is connected to a corresponding terminal 31 via a conductive connecting member 33. As will be described below, the connecting member 33 is formed by melting and integrating a protrusion 33A disposed on the terminal 31 before connection and a protrusion 33B disposed on the terminal 32 before connection, and then solidifying them.

[0052] in addition, Figure 4 The diagram shows 10 sets of terminals 31 and 32, but the number of terminals 31 and 32 is not limited to this.

[0053] Figure 5 This is a simplified side view illustrating an example of the connection structure between the suspension 10 and the slider 12. In the example shown, the slider 12 is a cuboid, but is not limited to this. The slider 12 is mounted on the armature plate 24.

[0054] The path of the aforementioned wiring 30 mostly passes through the tail 22 and front end 21 of the flexure 20 and finally reaches the armature 24. Figure 4 A portion of the multiple wirings 30 shown is connected to other electronic components, other than the slider 12, in the front suspension 10, for example. Such electronic components may have, for example, an actuating element that causes the latch 24 to oscillate.

[0055] The flexural portion 20 also has a plurality of terminals 41 formed on one side surface 24a (the surface on which the slider 12 is mounted) of the latch 24. The plurality of terminals 41 are arranged side by side at intervals, for example, in a direction perpendicular to the length direction X.

[0056] The slider 12 has a side surface 12a intersecting the length direction X. The side surface 12a intersects the surface 24a at a specified angle. Figure 5 In the example, side surface 12a and surface 24s intersect.

[0057] The slider 12 has, for example, multiple elements 12b that can convert magnetic signals into electrical signals, such as MR elements. Data can be read from the disk 4 through these elements 12b. Additionally, the slider 12 has a coil that generates a magnetic field for writing data to the disk 4.

[0058] The slider 12 also has a plurality of terminals 42 provided on the side surface 12a. These terminals 42 are arranged side by side at intervals, for example, in a direction perpendicular to the length direction X. Each terminal 42 is connected to a corresponding terminal 41 via a conductive connecting member. As will be described below, the connecting member 43 is formed by melting and integrating a protrusion 43A disposed on the terminal 41 before connection and a protrusion 43B disposed on the terminal 42 before connection, and then solidifying them.

[0059] in addition, Figure 5The diagram shows six sets of terminals 41 and 42, but the number of terminals 41 and 42 is not limited to this.

[0060] (Terminal structure)

[0061] Figure 6 This is a simplified plan view of terminals 31 and 32 before connection according to an embodiment of the present invention. A plurality of terminals 31 provided on the gasket portion 23 are arranged at a certain interval G in the first direction D1. The terminals 31 are rectangular, with their longer sides lying in the second direction D2, which intersects the first direction D1. In this embodiment, the first direction D1 and the second direction D2 intersect perpendicularly. The first direction D1 is, for example, parallel to the length direction X.

[0062] One end of each terminal 31 in the second direction D2 is connected to the wiring 30. Each terminal 31 is provided with a conductive bump 33A. The bump 33A is formed of a metallic material. The metallic material of the bump 33A is, for example, an alloy, preferably solder.

[0063] Multiple terminals 32 and 31, identical to those on the flexible circuit board 11, are arranged at intervals G in the first direction D1. The shape of the terminals 32 is, for example, the same as that of the terminals 31. One end of each terminal 32 in the second direction D2 is connected to a wiring 34. Each terminal 32 is provided with a conductive bump 33B. The bump 33B is formed of the same material as the bump 33A.

[0064] Furthermore, the shape and arrangement of the terminal 41 provided on the armature 24 and the terminal 43 provided on the slider 12 can be the same as those of terminals 31 and 32. A protrusion 43A, identical to protrusion 33A, is provided on the terminal 41 before it connects to terminal 42. A protrusion 43B, identical to protrusion 33B, is provided on the terminal 42 before it connects to terminal 41. Figure 6 In the middle, the symbols of the connecting piece 24, the slider 12, the terminals 41 and 42, and the protrusions 43A and 43B are marked side by side, along with the symbols of their corresponding elements.

[0065] The following is for reference Figures 7 to 9 The structure of terminal 31 and bump 33A will be described. Terminal 32 and bump 33B can be used and... Figures 7 to 9 The terminals 31 and 33A described herein have the same structure. Furthermore, terminals 41 and 42, and the protrusions 43A and 43B disposed thereon, can also be applied and used... Figures 7 to 9 The terminal 31 and the bump 33A described have the same construction.

[0066] Figure 7This is a simplified plan view of the enlarged terminal 31. Terminal 31 has a first side S1 and a second side S2 intersecting the first direction D1, and a third side S3 and a fourth side S4 intersecting the second direction D2. These sides S1, S2, S3, and S4 constitute the shape of terminal 31. The first side S1 and the second side S2 are longer than the third side S3 and the fourth side S4. Wiring 30 is connected to the third side S3.

[0067] The first side S1 and the second side S2 each have a recess R in the first direction D1 that is recessed toward the center O of the terminal 31. The center O is the point where the center line C1 of the terminal 31 in the first direction D1 and the center line C2 of the terminal 31 in the second direction D2 intersect. The center line C1 is parallel to the second direction D2, and the center line C2 is parallel to the first direction D1. The terminal 31 may have a line-symmetrical shape with respect to the center lines C1 and C2, for example, but is not limited thereto.

[0068] By providing a recess R, the outer shape of terminal 31 includes not only the two ends in the second direction D2, but also a central portion between the two ends. Specifically, terminal 31 has a narrow width portion NP and a pair of wide width portions WP. The narrow width portion NP is the portion corresponding to the recess R, and is located between the pair of wide width portions WP. In other words, the narrow width portion NP and the wide width portions WP are side by side in the second direction D2. The narrow width portion NP includes a center O.

[0069] The narrow portion NP has a width Wa1 (first width) in the first direction D1. The wide portion WP each has a width Wa2 (second width) in the first direction D1. Width Wa2 is larger than width Wa1 (Wa1 < Wa2). Figure 7 In the example, the length of the narrow portion NP in the second direction D2 is greater than the length of each wide portion WP in the second direction D2. However, the length of the narrow portion NP in the second direction D2 can also be smaller than the length of each wide portion WP in the second direction D2.

[0070] The bump 33A, indicated by the dashed line, is disposed on the upper surface of the terminal 31 in the narrow width portion NP and the wide width portion WP. The bump 33A protrudes from the first side S1 and the second side S2 in the first direction D1 in the recess R.

[0071] Figure 8 For along Figure 7 A simplified cross-sectional view of terminal 31 (width WP) and bump 33A of line VIII-VIII. Terminal 31 has a conductive layer 310 and an electroplated layer 311 covering the upper and side surfaces of the conductive layer 310. The conductive layer 310 and the electroplated layer 311 are made of different metallic materials, for example. Wiring 30 is made of the same metallic material as the conductive layer 310, for example, and is integrally formed with the conductive layer 310.

[0072] The lower surface F2 of terminal 31 contacts the surface 23a of pad portion 23. Surface 23a corresponds to the surface of an insulating layer such as polyimide. The lower surface F2 corresponds to the surface of the conductive layer 310 that is not covered by the electroplated layer 311.

[0073] Bump 33A covers the upper surface F1. Figure 8 In the example, although bump 33A does not contact the first side S1 and the second side S2 of the side surface of terminal 31, bump 33A can still cover at least a portion of these side surfaces. Figure 8 In the cross-section, the surface RF of the protrusion 33A is shaped like a part of an ellipse.

[0074] Figure 9 For along Figure 7 A simplified cross-sectional view of terminal 31 (narrow width NP) and bump 33A of the IX-IX line. This cross-section can be along... Figure 7 The cross-section shown by centerline C2 can also be a cross-section through center O.

[0075] As described above, since the width Wa1 of the narrow portion NP is smaller than the width Wa2 of the wide portion WP, the protrusion 33A bulges upwards. Therefore, with... Figure 8 Compared to the example, the surface RF is nearly circular.

[0076] Within center O, bump 33A has a height Z1 (first height). Height Z1 is the height relative to the lower surface F2 (or surface 23a) of terminal 31. In other words, height Z1 is equivalent to the distance from the lower surface F2 to the center O of surface RF. Height Z1 can also be described as the combined height of bump 33A and terminal 31. Height Z1 is greater than width Wa1 (Z1 > Wa1).

[0077] The height of bump 33A is maximum at, for example, the center O. In this case, height Z1 is the maximum height of bump 33A. For example, along... Figure 7 In the cross-section of protrusion 33A along centerline C1, the height of protrusion 33A gradually decreases from center O towards the third side S3 and the fourth side S4. In this cross-section, it can be said that the height of protrusion 33A at the narrow width NP is generally greater than the height of protrusion 33A at the wide width WP.

[0078] exist Figure 9 In the cross-section, protrusion 33A has a width Wb1. For example, width Wb1 is greater than width Wa1 (Wb1 > Wa1). Furthermore, from... Figure 7 As can be seen from the shape of the protrusion 33A, the width of the protrusion 33A disposed on the wide part WP in the first direction D1 is also larger than the width of the protrusion 33A disposed on the narrow part NP in the first direction D1.

[0079] A material layer, such as solder-based bumps 33A, is formed on the upper surface of terminal 31 by screen printing, and then melted (reflowed) in an oven, followed by hardening to form bumps 33A. Due to the surface tension during melting, the surface RF of bumps 33A becomes... Figure 8 and Figure 9 The circle shown.

[0080] exist Figure 9 The diagram shows the outline of terminal 31X and protrusion 33X according to a comparative example. Terminal 31X does not have a recess R. In other words, Figure 9 The shape of terminal 31X shown is... Figure 8 The terminals 31 in the cross-section have the same shape. The width of the bump 33X formed on such a terminal 31X is larger than the width Wb1.

[0081] (Connection method of suspension and electronic components)

[0082] Figure 10 This is an example flowchart illustrating the connection method between the suspension 10 and the electronic components (flexible circuit board 11 and slider 12).

[0083] First, prepare the suspension 10, flexible circuit board 11, and slider 12 (step ST1). In the suspension 10, the terminal 31 is equipped with the aforementioned components. Figures 7 to 9 The bump 33A is described. The terminals 32 of the flexible circuit board 11, the terminals 41 of the suspension 10, and the terminals 42 of the slider 12 are also equipped with bumps 33B, 43A, and 43B, which are the same as bump 33A.

[0084] Next, the bumps 33A on each terminal 31, 33B on each terminal 32, 43A on each terminal 41, and 43B on each terminal 42 are flattened (step ST2). This flattening step is achieved, for example, by mechanically pressing the bumps 33A, 33B, 43A, and 43B.

[0085] Figure 11 A simplified cross-sectional view is shown to illustrate terminal 31 and the flattened protrusion 33A. This cross-section is... Figure 9 The same cross-section along centerline C2, passing through center O. Hereinafter, the flattened protrusion 33A will be referred to as protrusion 33Af.

[0086] exist Figure 11In the example, a flat surface FLT is formed on the surface RF of the bump 33Af. The flat surface FLT is, for example, parallel to the lower surface F2. At the center O, the bump 33Af has a height Z2 (second height). The height Z2 is the same as the height Z1, which is the height based on the lower surface F2 of the terminal 31. In other words, the height Z2 is equivalent to the distance from the lower surface F2 to the center O of the surface RF (flat surface FLT).

[0087] The height Z2 is, for example, smaller than the width Wa1 of terminal 31 (Z2 < Wa1). That is, although the height of the bump 33A at center O is greater than the width Wa1 before planarization, it becomes smaller than the width Wa1 after planarization. The height Z2 is preferably more than 15% smaller than the height Z1.

[0088] exist Figure 11 In the cross-section, the protrusion 33Af has a width Wb2. The width Wb2 is larger than the width Wb1 (Wb1 < Wb2). That is, the width of the protrusion 33Af in the first direction D1 is increased by planarization.

[0089] Furthermore, the flat surface FLT includes not only the surface RF of the bump 33Af on the narrow width portion NP, but also the surface RF on the wide width portion WP. However, the height of the bump 33A at the wide width portion WP is smaller than the height at the narrow width portion NP. Therefore, the rate of increase from the width of the bump 33A to the width of the bump 33Af in the wide width portion WP is less than the rate of increase from the width of the bump 33A to the width of the bump 33Af in the narrow width portion NP.

[0090] The relationships between planarized bump 33B and terminal 32, planarized bump 43A and terminal 41, and planarized bump 43B and terminal 42 are related to... Figure 11 The relationship between the bump 33Af and the terminal 31 shown is the same.

[0091] After planarizing the bumps 33A, 33B, 43A, and 43B, align the suspension 10 and the flexible circuit board 11, as well as the suspension 10 and the slider 12, to bring them into a suitable connection state (e.g., Figure 10 Step ST3 is shown.

[0092] Figure 12 This is a simplified cross-sectional view between the aligned suspension 10 (shim portion 23) and flexible circuit board 11. Hereinafter, the planarized bump 33B will be referred to as bump 33Bf. In such... Figure 4 In the example shown, the surface 11a of the flexible circuit board 11 and the surface 23a of the pad 23 intersect perpendicularly. Therefore, in step ST3, the pad portion 23 and the flexible circuit board 11 are aligned so that surfaces 11a and 23a are as shown. Figure 4 The two objects intersect perpendicularly as shown.

[0093] From another perspective, the alignment of the gasket portion 23 and the flexible circuit board 11 causes the virtual plane V1 (first plane) including the upper surface F1 of the terminal 31 and the virtual plane V2 (second plane) including the upper surface F1 of the terminal 32 to intersect. Figure 12 In the example, these virtual planes V1 and V2 intersect perpendicularly.

[0094] With the spacer portion 23 and the flexible circuit board 11 aligned, the bumps 33Af and 33Bf gradually approach each other. The bumps 33Af and 33Bf can then... Figure 12 They can be separated from each other, or they can be in contact with each other.

[0095] Additionally, the terminals 41 and 42 of the suspension 10 (lever 24) and slider 12 have and Figure 12 Terminals 31 and 32 are shown in the same positional relationship. At this time, the protrusions 43A and 43B that are close to each other can be separated from each other or in contact with each other.

[0096] After aligning the suspension 10 and flexible circuit board 11, and the suspension 10 and slider 12 respectively, the bumps 33A, 33B, 43A, and 43B are melted (reflowed) by, for example, local heating of them. Figure 10 Step ST4 is shown.

[0097] exist Figure 12 In the diagram, the shapes of the molten bumps 33A and 33B are represented by dashed lines. The shapes of the bumps 33A and 33B are brought close to their shapes before planarization in step ST2 by melting, thereby bringing the bumps 33A and 33B into contact with each other and forming an integral unit.

[0098] Figure 13 A simplified cross-sectional view is shown to illustrate the state of the integrated bumps 33A and 33B after cooling and solidification. The integrated bumps 33A and 33B solidify to form the aforementioned connecting member 33. Thus, terminals 31 and 32 are electrically connected via the connecting member 33.

[0099] The molten bumps 43A and 43B also solidify in an integrated state, forming the aforementioned connecting component 43. Thus, terminals 41 and 42 are electrically connected through the connecting component 43.

[0100] (Implementation Results)

[0101] Examples of the effects achievable in this embodiment will be provided. Furthermore, while the following description focuses primarily on terminal 31 and bump 33A, the same effects can also be achieved with terminal 32 and bump 33B, terminal 41 and bump 43A, and terminal 42 and bump 43B.

[0102] In cases where a high-density configuration of terminals 31 is required Figure 6The spacing G shown will become smaller. At this time, the risk of short circuit between adjacent bumps 33A disposed on terminal 31 will increase. This risk is particularly pronounced when the bumps 33A are planarized in this embodiment. If terminal 31 is simply a rectangle, the width of the bumps 33A is greatest at the center of the second direction D2 before and after planarization.

[0103] In contrast, in this embodiment, terminal 31 has a recess R. Therefore, before and after planarization, the width of the bump 33A at the central portion (narrow width portion NP) can be reduced. As a result, the risk of short circuits between adjacent bumps 33A disposed on terminal 31 can be reduced.

[0104] Another method to reduce the aforementioned short-circuit risk is to reduce the number of bumps 33A disposed on terminal 31. However, in this case, the height of the bumps 33A before planarization will also be reduced. This may lead to issues such as... Figure 12 The diagram shows a situation where the bumps 33A and 33B do not make contact after the alignment and melting, resulting in poor contact between terminals 31 and 32.

[0105] Conversely, in this embodiment, the height Z1 at the center O of the protrusion 33A before planarization is greater than the width Wa1 of the terminal 31 at the narrow portion NP. As long as this level of height Z1 is ensured, the protrusions 33A and 33B after planarization and melting can be well connected.

[0106] In this embodiment, bumps 33A and 33B are planarized before the suspension 10 and flexible circuit board 11 are aligned. If alignment is performed without planarization, bumps 33A and 33B may interfere with each other, resulting in decreased alignment accuracy. Conversely, if bumps 33A and 33B are planarized before alignment, the planarized bumps 33A and 33B are less likely to interfere with each other, improving alignment accuracy. Even if there is a gap between bumps 33Af and 33Bf before melting, after melting, bumps 33Af and 33Bf will return to their pre-planarization shape, and their height will increase. Therefore, connecting bumps 33A and 33B is possible.

[0107] Figure 9 The terminal 31X shown in the comparative example does not have the aforementioned recess R. Assuming that the protrusion 33X disposed on this terminal 31X has the same height Z1 at center O as the protrusion 33A, then in the case of... Figure 9 Near the cross-section shown, the material constituting bump 33A can be less than that constituting bump 33X. As a result, even if the height Z1 of bump 33A at center O is increased, the amount of material constituting bump 33A can be reduced.

[0108] Furthermore, this embodiment discloses a method for increasing the height of the bump 33A near the center O by providing a narrow portion NP between the wide portion WP. Another method for increasing the height of the bump 33A near the center O is to make the width of the terminal 31 the same as the narrow portion NP. However, in this case, the bump 33A is formed by screen printing and the bump 33A is melted into... Figure 9 When the shape shown is used, the bump 33A may fall off the terminal 31.

[0109] Conversely, if a wider portion WP is provided as in this embodiment, the portion of the molten bump 33A that cannot be retained in the narrower portion NP will flow into the wider portion WP. Therefore, the bump 33A is less likely to fall off the terminal 31. In this embodiment, while reducing the width of the terminal 31 to ensure the height of the bump 33A, it is also possible to increase the size of both ends of the terminal 31 in the second direction D2 to prevent the bump 33A from falling off the terminal 31.

[0110] In addition to the above, this embodiment can also achieve various other suitable effects.

[0111] (Example)

[0112] Figure 14 A table illustrating Embodiments 1, 2, and a comparative example of the terminal 31 and the bump 33A is provided. The terminals 31 according to Embodiments 1 and 2 each have the following characteristics: Figure 7 The shape shown. Terminal 31X according to the comparative example does not have a recess R. According to Embodiments 1 and 2, the width of the width portion WP in the first direction D1 is the same as the width of terminal 31X in the first direction D1. According to Embodiments 1 and 2, the length of terminal 31 in the second direction D2 is the same as the length of terminal 31X in the second direction D2.

[0113] According to Embodiment 1, the width Wa1 of terminal 31 (reference) Figure 9 The width of terminal 31 is 0.145mm, and the width Wa2 (reference) is 0.145mm. Figure 8 The height is 0.185 mm. A height Z1 (reference) is formed at the center O on this terminal 31. Figure 9 The bump 33A is 0.160mm.

[0114] According to Embodiment 2, the width Wa1 of terminal 31 is 0.145 mm, and the width Wa2 of terminal 31 is 0.215 mm. A protrusion 33A with a height Z1 of 0.151 mm at the center O is formed on terminal 31.

[0115] According to the comparative example, the width of terminal 31X is 0.185 mm at any position in the second direction D2. A protrusion 33X with a height Z1 of 0.163 mm at the center O is formed on terminal 31X.

[0116] According to Embodiment 1, the width Wb1 of the protrusion 33A at center O (referencing) Figure 9 This 0.205mm, after flattening, represents the width Wb2 of bump 33A (bump 33Af) at center O (reference). Figure 11 The width of the bump 33A at the center O is 0.303 mm. According to Example 2, the width Wb1 of the bump 33A at the center O is 0.193 mm, and after flattening, the width Wb2 of the bump 33A (bump 33Af) at the center O is 0.275 mm.

[0117] According to the comparative example, the width Wb1 of the bump 33X at the center O is 0.229 mm, and after flattening, the width Wb2 of the bump 33X at the center O is 0.337 mm.

[0118] The width Wb1 of the bump 33A according to Embodiments 1 and 2 is smaller than that of the bump 33X according to the comparative example. Furthermore, the width Wb2 of the bump 33A (bump 33Af) according to Comparative Examples 1 and 2 is smaller than that of the bump 33X according to the comparative example. Therefore, it can be concluded that in the terminals 31 and bumps 33A according to Embodiments 1 and 2, the risk of short circuits occurring between adjacent bumps 33A before and after planarization is lower than in the comparative example.

[0119] Furthermore, in both Embodiments 1 and 2, a well-shaped protrusion 33A can be formed that does not fall off the terminal 31. Also, when the protrusion 33A is connected to the protrusion 33B of another terminal 32 using the connection method of this embodiment, a well-shaped connecting member 33 can be formed.

[0120] Furthermore, it is not necessary for terminals 31 and bump 33A, terminals 32 and bump 33B, terminals 41 and bump 43A, and terminals 42 and bump 43B to all have the same structure. For example, terminals 31, 32, 41, and 43 can have different widths Wa1 and Wa2, respectively. Also, bumps 33A, 33B, 43A, and 43B before planarization can have different widths Wb1 and heights Z1, and bumps 33A, 33B, 43A, and 43B after planarization can also have different widths Wb2 and heights Z2.

[0121] In the first embodiment, it is illustrated that terminal 31 and bump 33A, terminal 32 and bump 33B, terminal 41 and bump 43A, and terminal 42 and bump 43B all have a function Figures 7 to 9 The structure described herein is as follows. However, it is not necessary to use this structure for all combinations of these terminals and bumps. Several embodiments based on this viewpoint are disclosed below. In each embodiment, the structure not specifically mentioned is the same as in the first embodiment.

[0122] (Second Implementation)

[0123] In the second embodiment, the terminal 31 and the protrusion 33A of the suspension 10 have the function of... Figures 7 to 9 The structure is described. However, the terminals 32 and bumps 33B of the flexible circuit board do not have the functionality of... Figures 7 to 9 The structure is described. For example, terminal 32 has a constant width of rectangle in the first direction D1. Even in this structure, terminal 31 and bump 33A can achieve the same effect as in the first embodiment.

[0124] (Third Implementation)

[0125] In the third embodiment, the terminal 41 and the protrusion 43A of the suspension 10 have the function of... Figures 7 to 9 The structure is described. However, the terminals 42 and protrusions 43B of slider 12 do not have a usable... Figures 7 to 9 The structure is described. For example, terminal 42 has a constant width of rectangle in the first direction D1. Even in this structure, terminal 41 and bump 43A can achieve the same effect as in the first embodiment.

[0126] (Fourth Implementation)

[0127] In the fourth embodiment, the terminal 31 and the protrusion 33A of the suspension 10 have the function of... Figures 7 to 9 The structure is described. However, the terminals 32 and bumps 33B of the flexible circuit board 11 do not have a usable... Figures 7 to 9 The structure is described. For example, terminal 31 has a constant width of rectangle in the first direction D1. Even in this structure, terminal 31 and bump 33B can achieve the same effect as in the first embodiment.

[0128] (Fifth Implementation)

[0129] In the fifth embodiment, the terminal 41 and the protrusion 43A of the suspension 10 have the function of... Figures 7 to 9 The structure is described. However, the terminals 42 and protrusions 43B of slider 12 do not have a usable... Figures 7 to 9 The structure is described. For example, terminal 41 has a constant width of rectangle in the first direction D1. Even in this structure, terminal 42 and bump 43B can achieve the same effect as in the first embodiment.

[0130] (Modified Example)

[0131] Figure 7 The shape of terminal 31 shown is only one example of the shapes applicable to terminals 31, 32, 41, and 42. Terminals 31, 32, 41, and 42 can also be various other shapes. The first to third variations related to the shape of terminal 31 are disclosed below. The shapes of terminal 31 according to these variations can also be applied to terminals 32, 41, and 42.

[0132] Figure 15 This is a simplified plan view of the terminal according to the first modified example. In the first modified example, a recess R is provided on the second side S2, and no recess R is provided on the first side S1. Even with this structure, a narrow portion NP and a wide portion WP are formed on the terminal 31. Therefore, the same effect as in the first embodiment can be achieved.

[0133] Figure 16 This is a simplified plan view of terminal 31 according to the second modification. In the second modification, the first side S1, the second side S2, and the fourth side S4 are each provided with a recess R. By providing a recess R on the fourth side S4, the height Z1 of the protrusion 33A at the center O can be further increased.

[0134] Figure 17 This is a simplified plan view of terminal 31 according to the third modification. In the third modification, terminal 31 has an outer diameter of a circle CR, indicated by a dashed line. Furthermore, terminal 31 has four recesses R that are recessed towards the center O. The recesses R are, for example, semi-circular. Even with this shape, the height Z1 of the protrusion 33A at the center O can be increased.

[0135] The cross-sectional structure of terminals 31, 32, 41, and 42 is not limited to... Figure 8 and Figure 9 The example shown.

[0136] Figure 18 A simplified cross-sectional view is shown to illustrate other structures that can be applied to terminal 31. The structure of terminal 31 shown in this figure can also be applied to terminals 32, 41, and 42.

[0137] exist Figure 18 In the example, a conductive layer 310 is formed on the surface 23a of the pad portion 23, and the conductive layer 310 is covered by an electroplated layer 311. Furthermore, an insulating layer 320 is formed on the electroplated layer 311. The insulating layer 320 has an opening OP. The electroplated layer 311 is exposed through the opening OP from the insulating layer 320. This exposed area corresponds to the terminal 31.

[0138] Even when the shape of the terminal 31 is determined by the opening OP of the insulating layer 320 as described above, the same shape as the terminal 31 in the above embodiments can be used. Thus, the same effect as in the above embodiments can be achieved.

[0139] The various embodiments and modifications should not limit the scope of the present invention to the structures disclosed in the above embodiments and modifications. The present invention can also be implemented by various modifications to the structures disclosed in the various embodiments and modifications.

Claims

1. A suspension for a disk drive, comprising: Load-bearing beam The flexural portion overlaps with the load-bearing beam. The first terminal is disposed on the flexible portion. The first protrusion is disposed on the upper surface of the first terminal. The first terminal includes: A narrow width portion having a first width in a first direction and being contained at the center of the first terminal in the first direction, and the first direction intersecting a second direction. A pair of width portions, each of which has a second width that is larger than the first width in the first direction. The narrow portion is located between the pair of wide portions in the second direction. The first protrusion has a first height at its center, with reference to the lower surface of the first terminal. The first height is greater than the first width.

2. The suspension for a disk drive according to claim 1, The first terminal has a first side and a second side that intersect the first direction. At least one of the first side and the second side includes a recessed portion in the narrow width direction.

3. The suspension for a disk drive according to any one of claims 1 or 2, wherein the first height is smaller than the second width.

4. A connection method, the connection method being an electrical connection of a suspension for a disk drive according to claim 1, comprising an electronic component including a second terminal and a second protrusion disposed on the second terminal, the connection method comprising: Flatten the first bump, Align the suspension and the electronic components so that the first bump and the second bump are close together, and a first plane including the upper surface of the first terminal and a second plane including the upper surface of the second terminal intersect. The first bump and the second bump are connected by melting the first bump and the second bump.

5. The connection method according to claim 4, wherein the flattened first protrusion has a second height at its center, based on the lower surface of the first terminal. The second height is more than 15% smaller than the first height.

6. The connection method according to claim 5, wherein the second height is smaller than the first width.

7. The connection method according to any one of claims 4 to 6, wherein the electronic component is a flexible circuit board or a slider constituting a magnetic head.

8. An electronic component, said electronic component being electrically connected to a disk drive via a suspension, comprising: Terminal 2, The second protrusion is disposed on the upper surface of the second terminal. The second terminal includes: A narrow width portion having a first width in a first direction and including the center of the second terminal in the first direction, and the first direction intersecting with a second direction. A pair of width portions, each of which has a second width that is larger than the first width in the first direction. The narrow portion is located between the pair of wide portions in the second direction. The second protrusion has a first height at its center, with the lower surface of the second terminal as a reference. The first height is greater than the first width.

9. The electronic component according to claim 8, The second terminal has a first side and a second side that intersect the first direction. At least one of the first side and the second side includes a recessed portion in the narrow width direction.

10. The electronic component according to any one of claims 8 or 9, wherein the first height is smaller than the second width.

11. A connection method, the connection method being an electrical connection of a disk drive suspension comprising a first terminal and a first bump disposed on the first terminal, and the electronic component of claim 8, the connection method comprising: Flatten the second bump. Align the suspension and the electronic components so that the first bump and the second bump are close together, and a first plane including the upper surface of the first terminal and a second plane including the upper surface of the second terminal intersect. The first bump and the second bump are connected by melting the first bump and the second bump.

12. The connection method according to claim 11, wherein the planarized second protrusion has a second height at its center, based on the lower surface of the second terminal. The second height is more than 15% smaller than the first height.

13. The connection method according to claim 12, wherein the second height is smaller than the first width.

14. The connection method according to any one of claims 11 to 13, wherein the electronic component is a flexible circuit board or a slider constituting a magnetic head.

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