JP2012146353A - Flexible wiring board, connection structure of wiring board and method of manufacturing thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible wiring board and the like capable of obtaining a connection part having durability by securely connecting a terminal located on the bottom of a connection pad part and an exposed lead.SOLUTION: In a connection structure of a main flexible wiring board 20 and a flexible wiring board 10, the main flexible wiring board has a terminal 21 located on the bottom of a connection pad part K in which an insulating layer 23 is removed and the flexible wiring board 10 has an exposed lead 11 at a terminal part T in which an insulating layer 13 is removed. The exposed lead is processed to have parts 11a and 11c which overhang to the connection part of the wiring board and a projecting part of the exposed lead is electrically connected to the terminal 21 of the connection pad part.

Description

  The present invention relates to a flexible wiring board, a wiring board connection structure, and a method of manufacturing the same.

  A hard disk drive (HDD) includes an actuator that moves a head to an arbitrary position on a magnetic disk. The actuator is driven by a voice coil or the like and swings about a pivot shaft (swing shaft), thereby moving the head in the radial direction of the magnetic disk. As a result, the head element unit can access any track of the magnetic disk and perform data read / write processing. The flexible wiring board and the head support component that transmit signals from the head are collectively referred to as a flexure, a (head) suspension, and the like. A component complex that swings around the pivot axis including the suspension, the pivot axis, and the like is called an APFA (Actuator Pivot Flex Assembly). The APFA also includes a housing-side flexible wiring board or a main flexible wiring board arranged to transmit a signal from the flexure to the signal processing unit of the HDD. One end of the main flexible wiring board is fixed to a housing-fixed connector or the like, and a connection pad portion at the other end is fixed to the outer surface of the pivot shaft to be conductively connected to a lead in the flexure (Patent Document 1). The connector may be mounted on the main flexible wiring board or may be a separate body. In addition, a preamplifier may be mounted on the main flexible wiring board.

Among the above components, the suspension (or flexure) transmits signals between the head and a mechanical component including a thin metal plate such as a plate-shaped component (load beam, mount plate) that supports the gimbal that holds the head. Flexible wiring board (single unit). The suspension is attached to a triangular arm formed of a relatively thick metal plate. The arm is driven by the actuator described above to rotate around the pivot axis.
The head-side flexible wiring board electrically connects the head and the mounting wiring body that is the main flexible wiring board. A signal between the head and the head is transmitted to an electronic circuit through a connector fixed to the main flexible wiring board and the board of the housing.
The flexible wiring board on the head side and the main flexible wiring board on the casing side are electrically connected to each other at terminals (electrodes) on the outer surface portion of the pivot shaft. The conductor pattern constituting the terminal (electrode) of the flexible wiring board on the head side is exposed and is called a flying lead or an exposed lead. The terminal of the main flexible wiring board is a wiring located on the base material at the bottom of the connection pad part that forms a concave part or a narrow part where the insulating layer (cover lay) of the flexible wiring board on the housing side is partially removed. is there. In general, solder bonding, ultrasonic bonding, or the like is used for this conductive connection. Solder bonding has been widely used until now, but there is a problem such as evaporation of the solvent, and there is a tendency for the use of ultrasonic bonding to increase. A method for enabling efficient and reliable bonding in ultrasonic bonding is disclosed (Patent Document 2).

JP 2004-342270 A JP 2007-173362 A

However, there is a problem that it is difficult to form a durable and reliable ultrasonic bonded portion due to the unique shape (concave or narrow) of the connection pad portion of the main flexible wiring board. That is, in ultrasonic bonding, the exposed lead of the main flexible wiring board is pushed into the connection pad portion of the main flexible wiring board by an ultrasonic welding jig, and the exposed lead and the terminal of the connection pad portion are in contact with each other. Join by applying sonic vibration energy. For this reason, it was recognized that the exposed lead often spring-backs after joining and partially restored to its original flat shape to separate the ultrasonic joining part. Therefore, there is a demand for a connection method that can realize a durable connection or joint between the terminals of the head-side flexible wiring board and the main flexible wiring board that can overcome the above-described problems.
Also, not limited to the APFA in the HDD, many other electronic devices usually have a connection pad portion formed in a recess surrounded by an insulating layer, and an exposed lead is surely provided on a terminal located at the bottom of the recess. A technique for forming a durable conductive connection portion by connecting to a metal is highly versatile and important. In the above description and the following description, the term “connection” is used for ACF and the like, and the term “bonding” is used for ultrasonic bonding and the like. Good.

  The flexible wiring board according to the present invention can provide a durable connection by securely connecting the terminal located at the bottom of the connection pad part that forms a recess or a gap in the wiring board and the exposed lead of the flexible wiring board. It is an object of the present invention to provide a wiring board, a wiring board connection structure, and a manufacturing method thereof.

The flexible wiring board of the present invention includes an exposed lead in which a conductor pattern is exposed at a terminal portion from which an insulating layer is removed. This flexible wiring board is characterized in that the exposed lead is processed so as to have a portion protruding to one surface side of the flexible wiring board.
According to said structure, the exposure lead is processed beforehand so that it may have a part which protrudes to the connection pad part side of a connection other party. For this reason, it is possible to conduct conductive connection with the terminal located at the bottom of the connection pad portion without applying force to the exposed lead when conducting conductive connection. For this reason, a highly durable conductive connection part can be formed easily and reliably.
In the case of the HDD, the flexible wiring board may be a single flexible wiring board included in the suspension, or a flexible wiring board composite including a flexible wiring board alone to which a member such as a suspension board is attached. . When referring to a flexible wiring board for HDD, it refers to both the above-mentioned flexible wiring board alone and the flexible wiring board composite. In general, a flexible wiring board is not limited to an HDD, and includes a special-purpose and general-purpose flexible wiring board.
The exposed lead is called a flying lead in the HDD APFA. Since the flexible wiring board is not limited to the HDD, the term “exposed lead” is used here.

The protruding portion of the exposed lead can be extended outside one surface.
As a result, no restoring force is generated in the separation direction, so that the connection portion between the exposed lead and the terminal of the connection partner can be made more easily and highly durable.

A sub-terminal portion having an exposed lead from which the conductor pattern is exposed is provided in a region different from the terminal portion, and the exposed lead of the sub-terminal portion has a protruding portion in the same direction as the protruding portion of the exposed lead in the terminal portion. Can be processed to have.
Accordingly, it is possible to prevent a situation in which the exposed lead of the sub-terminal portion is blocked by the exposed lead protruding from the terminal portion and does not reach the terminal of the connection partner.

This flexible wiring board can be included in a head suspension of a hard disk drive (HDD).
As a result, in the actuator pivot flex assembly (APFA), the above flexible wiring board is used as a suspension, and the conductive connection is easily and reliably conducted to the terminal at the bottom of the connection pad portion of the casing-side flexible wiring board. The portion can be made highly durable.

The wiring board connection structure of the present invention is a connection structure between a wiring board and a flexible wiring board. In this connection structure, the wiring board has a connection pad portion from which the insulating layer is removed and a terminal located on the base material forming the bottom of the connection pad portion, and the flexible wiring board is a terminal from which the insulating layer is removed. The exposed lead is exposed to the conductive pattern, and the exposed lead is processed to have a portion that protrudes to the connection pad portion of the wiring board. It is characterized in that it is conductively connected to the terminal.
With the above configuration, the exposed lead is projected in the form as it is without applying a pressing force to the exposed lead of the flexible wiring board with respect to the terminal of the wiring board located at the bottom of the recess or the space surrounded by the insulating layer. The parts can be brought into contact. For this reason, a highly durable conductive connection part can be obtained easily. That is, a highly reliable connection structure can be obtained.
Here, the wiring board may be anything as long as the wiring board has a terminal located at the bottom of the connection pad part that forms a recess or a gap. A flexible wiring board may be used, and other wiring boards may be used.

The wiring board has a terminal in a sub-connection pad part that is a different area from the connection pad part, and the flexible wiring board has an exposed lead in which a conductor pattern is exposed in a sub-terminal part that is a different area from the terminal part. The exposed lead of the sub terminal portion is processed so as to have a portion protruding in the same direction as the exposed lead portion of the terminal portion, and the terminal of the sub connection pad portion and the exposed lead of the sub terminal portion are Can be conductively connected.
Thereby, the exposed lead of the sub-terminal portion of the flexible wiring board and the terminal of the sub-connecting pad portion of the wiring board can be easily and reliably connected to obtain a highly durable conductive connection portion. That is, the connection between the exposed lead of the different sub-connecting portion and the terminal in the other region of the wiring board can be prevented from being hindered by the exposed lead protruding at the terminal portion of the flexible wiring board.

Conductive connection between the exposed lead protruding portion of the flexible wiring board and the terminal of the wiring board is anisotropic conductive film (ACF), anisotropic conductive paste (ACP), ultrasonic It can be made by at least one of bonding and solder bonding.
Thereby, an appropriate connection method can be adopted according to the situation.

The above-mentioned wiring board connection structure can be included in an actuator pivot flex assembly (APFA) of a hard disk drive (HDD).
Thereby, the exposed lead of the flexible wiring board included in the suspension and the terminal at the bottom of the connection pad portion of the housing-side flexible wiring board can be easily and surely connected to each other. Further, when manufacturing the APFA of the HDD, an appropriate connection method can be adopted depending on the situation.

The method for manufacturing a flexible wiring board according to the present invention includes a step of preparing a flexible wiring board including a conductor pattern, and a step of forming a terminal portion including an exposed lead made of a conductor pattern by removing an insulating layer in a predetermined region of the flexible wiring board. And a step of processing the exposed lead in the terminal portion so as to have a portion protruding to one surface side.
As a result, a flexible wiring board that can be easily conductively connected to a terminal located at the bottom of the space between the insulating layers of the wiring board can be easily manufactured. The exposed lead can be processed by pressing it with a mold. The thickness of the flexible wiring board is several tens μm to several hundreds μm even if it is thick. For this reason, it is not necessary to take a large stroke in the pressing process. For example, it is important to use a die that properly plastically processes the corner portion of the trapezoidal shape or a pressing tool.

A method for manufacturing a wiring board connection structure according to the present invention includes a flexible wiring board manufactured by the above method, and a wiring board having terminals located on a base material that forms the bottom of a connection pad part from which an insulating layer has been removed, and This is a manufacturing method of the connection structure. The terminal located on the bottom of the connection pad portion of the wiring board is aligned with the exposed lead of the flexible wiring board, and the terminal of the connection pad portion and the exposed lead of the terminal portion are conductively connected.
By the above method, a highly durable conductive connection part can be manufactured easily and reliably.

  According to the present invention, it is possible to reliably connect the terminal located at the bottom of the connection pad portion that forms a recess or a gap in the wiring board and the exposed lead of the flexible wiring board to obtain a durable connection portion.

(A) HDD which used the flexible wiring board etc. of Embodiment 1 of this invention, (b) The figure which shows the flexible wiring board. It is sectional drawing which shows the connection structure of the terminal part K of the flexible wiring board of FIG. 1, and the connection pad part of the main flexible wiring board. It is sectional drawing which shows the state which is going to form the connection structure of FIG. FIG. 4 is a perspective view of FIG. 3. It is a flowchart which shows the manufacturing method of a flexible wiring board. It is a flowchart which shows the formation method of a connection structure. It is sectional drawing which shows the connection structure in Embodiment 2 of this invention. It is a perspective view which shows the state which is going to form the connection structure of FIG.

(Embodiment 1)
FIG. 1A is a diagram showing an HDD 100 including an actuator pivot flex assembly (APFA) 50 including the flexure or flexible wiring board 10 according to the first embodiment of the present invention. FIG. 1B shows a flexible wiring board or flexure 10. The HDD 100 includes a magnetic disk 90 for recording data and a head (not shown in FIG. 1) for writing and reading data between the magnetic disk. The head is attached to a head support (load beam, mount plate, etc.) 31 and faces the magnetic disk 90. The head, the head support 31 and the like are attached to the tip of the arm 32. Some of the arms 32 target one magnetic disk, but many target a plurality of magnetic disks. A plurality of arms are overlapped with an interval, and the flexure or the flexible wiring board 10 reaches the outer surface of the pivot shaft 39 through the arm or the side surface. In the APFA 50, the flexure or the flexible wiring board 10 constitutes an important part that transmits a signal from the head to the main flexible wiring board or the casing-side flexible wiring board 20.
The APFA 50 includes an actuator driven by an arm 32, a pivot shaft 39, a voice coil motor, a voice coil 33, and the like, and rotates the head to a predetermined position on the magnetic disk 90. The flexure 10 and the main flexible wiring board 20 are also included in the APFA 50.

The main flexible wiring board 20 or the housing-side flexible wiring board 20 has a connector (not shown) at one end 22 while standing in the width direction with respect to the HDD floor so as not to hinder the rotation of the APFA 50. Etc. and fix it to the floor of the chassis. The connection pad portion K at which the terminal (electrode) 21 is arranged at the other end is fixed to the outer surface of the pivot shaft 39.
In FIG. 1B, the flexible wiring board or flexure 10 is provided with a head slider 19 at the tip of the suspension board 15, and the signal read by the head passes through the conductor pattern 13 and is exposed when the conductor pattern is exposed. It is transmitted to the lead or flying lead 11. The exposed lead or flying lead 11 located at the terminal portion T of the flexure 10 is conductively connected to the terminal 21 at the connection pad portion K of the main flexible wiring board 20.

FIG. 2 shows a conductive connection portion J in which the flying lead 11 in the terminal portion T of the flexure 10 and the terminal (electrode) 21 in the connection pad portion K of the main flexible wiring board 20 are conductively connected on the outer surface of the pivot shaft 39. FIG. FIGS. 3 and 4 are views showing a state when the conductive connection portion J shown in FIG. 2 is formed using an anisotropic conductive film (ACF) 5. However, the ACF is not shown in FIG.
In the connection pad portion K of the main flexible wiring board 20, the insulating layer or cover lay 23 is removed, and the terminals 21 on the base material 22 are exposed to the opening side. The terminal 21 is located on the base material 22 at the bottom between the insulating layers 23. That is, the terminal 21 is located at the bottom of the recess surrounded by the insulating layer 23.
Here, the recess may not be surrounded by an insulating layer on all four sides, for example, the insulating layer may be located on two opposite sides, and may be a so-called gap.

As shown in FIGS. 2 to 4, the feature of the present embodiment is that the flying lead 11 is plastically processed in advance so as to have a portion 11 a that protrudes toward the terminal 21 of the main flexible wiring board. is there.
When the flying lead 11 is flat and includes only parallel portions so as to be included in the extended portion of the insulating layer 13 as in the prior art, the following problem has occurred. When joining by ultrasonic joining etc., in order to contact the terminal 21 located in the bottom in the connection pad part K of the joining partner, a pressing force was applied to the flying lead 11 to join it. However, the flying lead 11 that has been pressed down may be partially or largely restored to the original flat shape so that a restoring force is generated so that the connection portion is separated and a connection failure may occur.

  However, as shown in FIGS. 2 to 4, in the present embodiment, the flying lead 11 is plastically processed in advance so as to have the overhang portions 11 a and 11 c. The overhanging portions 11 a and 11 c protrude from the parallel portion 11 b so as to be included in the insulating layer 13 while being bent at the bending portion 11 c in the thickness direction. In order to form a flat and long top portion such as the overhanging top portion 11a, it is important to perform plastic working so as to ensure a predetermined bending angle at the bent portion 11c. In the case of the flying lead 11 as shown in FIG. 2 to FIG. 4, even if the flying lead 11 is not pushed in by a pushing force, the protruding top portion 11a of the flying lead 11 is left as it is, while the ACF 5 is interposed therebetween. It is possible to conduct conductive connection to the terminal 21 located at. In a state where the flying top portion 11a is in contact with the terminal 21 with the ACF 5 interposed therebetween, as shown in FIG. 3, the pressure heating jig 41 is pressed against the flying lead 11 and heated under pressure to conduct electricity by the ACF. Realize the connection.

An overhanging top portion 11 a of the flying lead 11 greatly protrudes from the extension portion 11 b extending from the insulating layer 13 to the connection pad portion K side. Next, how much the overhanging top portion 11a should exceed from the surface of the insulating layer 13 on the connection pad side will be described. As shown in FIG. 3, it is assumed that the projecting top portion 11 a projects from the surface of the insulating layer 13 on the connection pad side by a distance a. In the connection pad portion K, the distance between the surface of the insulating layer or cover lay 23 and the surface of the terminal 21 or the surface of the ACF 5 disposed on the terminal 21 is b. At this time, by setting a≈b, as shown in FIG. 2, the flying lead 11 and the terminal 21 can form the connection portion J without being pushed and deformed even if the flying lead 11 is not pressed. it can.
As a result, a restoring force or the like does not occur after the conductive connection, and a highly durable conductive connection portion can be obtained easily and reliably.

In the above description, the conductive connection is made with the ACF 5 interposed therebetween, but other connection methods may be used. For example, ultrasonic bonding may be performed. In the case of ultrasonic bonding, naturally, the ACF 5 is not used, the pressure heating jig 41 shown in FIG. 3 is replaced with an ultrasonic vibration tool, and the ultrasonic wave is applied with the top 11a of the flying lead in contact with the terminal 21. What is necessary is just to press and join a vibration tool. In the case of ultrasonic bonding, it is preferable that the flying lead 11 of the flexure 10 and the terminal 21 of the main flexible wiring board 20 are subjected to a gold plating process on the surface and can be easily ultrasonically bonded.
Further, a conductive connection by solder may be applied to the conductive connection between the protruding top portion 11 a of the flying lead 11 and the terminal 21.

FIG. 5 is a flowchart showing a method of manufacturing the flexure or flexible wiring board 10. A flexible wiring board constituting the flexure is prepared, and the flying lead 11 is formed by removing the insulating layer of the terminal portion of the flexible wiring board. The flying lead 11 that is a conductor (wiring) pattern has one end extending from the insulating layer 13 and the other end entering the insulating layer 13. Between one end and the other end is bare. Even when the flying lead 11 enters the insulating layer 13 at both end sides to form wiring, the other end side may be terminated in a bare state. The flying lead regions may be divided into a plurality of locations, and the regions may be arranged side by side or arranged in a staggered manner (in the case of three or more regions).
Next, the flying lead 11 is plastically processed to form the overhang portions 11a and 11c. In order to ensure the angle of the bent portion 11c, it is preferable to perform press working using a mold. The flexible wiring board (single unit) 10 having the plastically processed flying lead 10 may be shipped as it is. Further, the head support 19 may be attached and shipped as a flexible wiring board (composite) 10.

The flying lead 11 of the flexible wiring board 10 is obtained by exposing a conductive pattern from the insulating layer 13. For the insulating layer 13 of the flexible wiring board 10, the base material 22 of the main flexible wiring board 20, and the cover lay 23, for example, a resin having versatility for a flexible wiring board such as polyimide or polyester can be used. In addition, it is particularly preferable to have high heat resistance in addition to flexibility, and as such a resin, for example, a polyamide-based resin or a polyimide-based resin such as polyimide or polyamideimide is preferable. used. The thickness of the insulating layer 13, the base material 22, and the coverlay 23 is preferably 1 to 30 μm.
A metal such as a copper foil can be used for the conductor pattern or the flying lead 11 or the terminal 21. In the case of ultrasonic connection, a gold plating layer is preferably formed. A copper or nickel plating layer can be formed on the base of the gold plating layer. The thickness of the terminal 21 is preferably in the range of 10 μm to 30 μm, for example, 18 μm. The thickness of the flying lead 25 is preferably in the range of 10 μm to 25 μm, for example 20 μm.

FIG. 6 is a flowchart showing a method of forming the connection portion J between the flying lead 11 of the flexure 10 and the terminal 21 of the main flexible wiring board 20. A composite flexure (suspension) is formed by adding a suspension board or the like to a flexible wiring board having a plastically processed flying lead formed by the procedure of FIG. The flying lead 11 of the flexure 10 and the terminal 21 of the main flexible wiring board 20 are conductively connected.
An anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like can be used as a conductive connection method. ACF5 is an anisotropic conductive adhesive containing conductive particles and having anisotropic conductivity. When a thermosetting adhesive resin is used, an epoxy resin, a high molecular weight epoxy resin, a phenoxy resin, a curing agent, And a thermosetting adhesive containing conductive particles as an essential component. As ACF5, for example, an epoxy resin and a phenoxy resin which are insulating thermosetting resins as main components and conductive particles such as nickel, copper, silver and gold dispersed therein can be used. By using an epoxy resin, it becomes possible to improve the film forming property, heat resistance, and adhesive strength of ACF5. The thickness of the ACF 5 is preferably in the range of 30 μm to 45 μm, for example 35 μm.

  Examples of the epoxy resin contained in ACF5 include bisphenol A type, F type, S type, AD type, or a copolymer type epoxy resin of bisphenol A type and bisphenol F type, naphthalene type epoxy resin, and novolak type. An epoxy resin, a biphenyl type epoxy resin, a dicyclopentadiene type epoxy resin, or the like can be used. Moreover, ACF5 should just contain at least 1 sort (s) among the above-mentioned epoxy resins.

  The molecular weights of the epoxy resin and the phenoxy resin can be appropriately selected in consideration of the performance required for ACF5. For example, when a high molecular weight epoxy resin is used, the film forming property is high, the melt viscosity of the resin at the connection temperature can be increased, and there is an effect that the connection can be made without disturbing the orientation of the conductive particles described later. On the other hand, when a low molecular weight epoxy resin is used, the effect of increasing the crosslink density and improving the heat resistance is obtained. Moreover, the effect of reacting with the above-mentioned hardening | curing agent rapidly at the time of a heating, and improving adhesive performance is acquired. Therefore, it is preferable to use a combination of a high molecular weight epoxy resin having a molecular weight of 15000 or more and a low molecular weight epoxy resin having a molecular weight of 2000 or less because the balance of performance can be achieved. In addition, the compounding quantity of a high molecular weight epoxy resin and a low molecular weight epoxy resin can be selected suitably.

  Moreover, ACF5 contains a latent curing agent as a curing agent, and a high adhesive force can be obtained by containing a curing agent for promoting the curing of the epoxy resin. A latent curing agent is a curing agent that is excellent in storage stability at low temperatures and hardly undergoes a curing reaction at room temperature, but rapidly undergoes a curing reaction by heat, light, or the like. Examples of such latent curing agents include imidazole, hydrazide, boron trifluoride-amine complexes, amine imides, polyamines, tertiary amines, alkyl ureas, and other amines, dicyandiamides, acid anhydrides, Phenol-based compounds and modified products thereof are exemplified, and these can be used alone or as a mixture of two or more.

Conductive particles are dispersed in ACF5, and the conductive particles include a large number of fine metal particles (for example, metal particles made of spherical metal particles or spherical resin particles plated with metal) in a linear form. It is formed of a metal powder having a connected shape or a needle shape, a shape having a large so-called aspect ratio. In the present embodiment, the proportion of conductive particles in ACF 33 is preferably 0.0001% by volume or more and 0.2% by volume or less.
Although the above explained in detail about the case where a thermosetting adhesive was used for ACF5, it is as above-mentioned that a thermoplastic resin may be used.

ACP may be used instead of ACF. The ACP is applied to the connection pad portion K of the main flexible wiring board 20 by screen printing or the like. The thickness should be the same as that of ACF. The flying lead 11 can be conductively connected by pressurizing and heating the flying lead 11 to the terminal side of the connection pad portion K with a pressure heating jig. ACP resin and conductive particles can be considered in the same manner as ACF.
Alternatively, the terminals of the connection pad portion K of the main flexible wiring board 20 and the protruding top portion 11a of the flying lead 11 may be aligned and conductively connected by ultrasonic connection. Further, it may be conductively connected with solder.

(Embodiment 2)
FIG. 7 is a diagram showing a flexible wiring board or flexure according to Embodiment 2 of the present invention and a connection structure between these flexures and terminals of the main flexible wiring board. FIG. 8 is a diagram showing a state in which the flexure 10 and the main flexible wiring board 20 are conductively connected (however, the ACF is not shown).
In FIG. 7, the connecting portion J is the same as the flexure 10 shown in FIG. 2 and the connecting portion J between the flexure 10 and the main flexible wiring board 20. In the present embodiment, the point where the sub-connecting portion Js is formed is different from the first embodiment.
The connection location between the main flexible wiring board 20 and the flexure 10 is not limited between the connection pad portion K and the terminal portion T. There are cases where conductive connection is made at other locations, the sub-connection portion Js. When the sub-connection portion Js is relatively close to the connection portion J, the base material 22 and the terminal 21 in the main flexible wiring board 20 extend from the connection portion J to the sub-connection portion Js in common. When the configuration of the present embodiment is not provided, the following problem occurs.
When the projecting portions 11a and 11c of the flying lead 11 are formed in the connection portion J, the flying lead 11 is separated from the terminal 21 by a predetermined distance if the flying lead 11 of the sub-connection portion Js remains flat. It is difficult to connect.

As with the terminal portion T, the overhang portions 11a and 11c can be formed on the flying lead 10 of the sub-terminal portion Ts. Since the flying lead 11 of the sub-terminal portion Ts has the overhang portions 11a and 11c, the terminal 21 in the sub-connecting pad portion Ks can be smoothly conductively connected without applying a pressing force to the flying lead 11. Although the ACF 5 is also used in the sub-connection portion Js, it is needless to say that ACP may be used. Further, instead of ACF and ACP, conductive connection by ultrasonic bonding may be used, or conductive connection by solder bonding may be used.
In FIG. 7, the connection partner of the flexible wiring board 10 is the main flexible wiring board 20 common to both the connection portion J and the sub-connection portion Js. However, most widely, in the flexible wiring board 10 of the present invention, the connection partner at the connection portion J may be different from the connection partner at the sub-connection portion Js.
The flexible wiring board 10 and the main flexible wiring board 20 shown in FIGS. 7 and 8 can be manufactured with only slight deformation according to the method in the first embodiment.

(Other embodiments)
In the first and second embodiments, the flexible wiring board for HDD and the connection structure have been described. However, the flexible wiring board and the connection structure of the present invention are not limited to the HDD, and can be used for other general purpose and special purposes.

  Although the embodiments and examples of the present invention have been described above, the embodiments and examples of the present invention disclosed above are merely examples, and the scope of the present invention is the implementation of these inventions. It is not limited to the form. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  According to the flexible wiring board or the like of the present invention, it is possible to reliably connect the terminal of the connection pad portion formed in the recess and the exposed lead to obtain a durable connection portion. In particular, it is a great feature that it can be applied to many connection methods such as ACF, ACP, ultrasonic connection, solder, etc., for the connection between the flexure for HDD and the main flexible wiring board.

5 ACF, 10 flexible wiring board (flexure), 11 terminal, 13 conductor (wiring) pattern, 15 suspension board, 19 head slider, 20 main flexible wiring board, 21 terminal, 22 end of main flexible wiring board, 31 head support , 32 arm, 33 voice coil, 39 pivot (swing) shaft, 50 APFA, 90 magnetic disk, 100 HDD, K main flexible wiring board connection pad, Ks sub connection pad, T flexure terminal, Ts sub Terminal part, J connecting part, Js sub connecting part.

Claims (10)

A flexible wiring board including an exposed lead from which a conductor pattern is exposed at a terminal portion from which an insulating layer is removed,
The flexible wiring board, wherein the exposed lead is processed so as to have a portion protruding to one surface side of the flexible wiring board.   2. The flexible wiring board according to claim 1, wherein a portion where the exposed lead protrudes protrudes beyond the one surface.   A sub-terminal portion having an exposed lead from which the conductor pattern is exposed is provided in a region different from the terminal portion, and the exposed lead of the sub-terminal portion is stretched in the same direction as a portion of the terminal portion where the exposed lead protrudes. The flexible wiring board according to claim 1, wherein the flexible wiring board is processed so as to have a protruding portion. The flexible wiring board according to claim 1, wherein the flexible wiring board is included in a head suspension of a hard disk drive (HDD). A connection structure between a wiring board and a flexible wiring board,
The wiring board has a connection pad part from which an insulating layer is removed, and a terminal located on a base material forming the bottom of the connection pad part,
The flexible wiring board has an exposed lead from which a conductor pattern is exposed at a terminal portion from which an insulating layer is removed, and the exposed lead is processed to have a portion protruding to a connection pad portion of the wiring board. And
The connection structure of a wiring board, wherein the protruding portion of the exposed lead is conductively connected to a terminal of the connection pad portion.   The wiring board has a terminal in a sub-connection pad portion that is a region different from the connection pad portion, and the flexible wiring board has the conductor pattern exposed in a sub-terminal portion that is a region different from the terminal portion. An exposed lead, and the exposed lead of the sub terminal portion is processed to have a portion protruding in the same direction as a portion of the exposed lead protruding in the terminal portion, and the terminal of the sub connecting pad portion, 6. The wiring board connection structure according to claim 5, wherein the exposed lead of the sub-terminal portion is conductively connected.   Conductive connection between the protruding portion of the exposed lead in the flexible wiring board and the terminal in the wiring board is an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), The wiring board connection structure according to claim 5 or 6, wherein the connection structure is formed by at least one of ultrasonic bonding and solder bonding.   The wiring board connection structure according to any one of claims 5 to 7, which is included in an actuator pivot flex assembly (APFA) of a hard disk drive (HDD). Preparing a flexible wiring board including a conductor pattern;
Removing the insulating layer in a predetermined region of the flexible wiring board to form a terminal portion including an exposed lead made of the conductor pattern;
And a step of processing the exposed lead in the terminal portion so as to have a portion protruding to one surface side. A method for manufacturing a connection structure, comprising: a flexible wiring board manufactured by the method according to claim 9; and a wiring board having a terminal located on a base material that forms the bottom of a connection pad part from which an insulating layer has been removed. And aligning the exposed lead of the flexible wiring board with the terminal located at the bottom of the connection pad portion of the wiring board, and conductively connecting the terminal of the connection pad portion and the exposed lead of the terminal portion. A method for manufacturing a connection structure for a wiring board, characterized in that:

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