JP6037216B2 - Flexure substrate for suspension - Google Patents

Description

  The present invention relates to a suspension flexure substrate used in a hard disk drive (HDD), and more particularly to a suspension flexure substrate excellent in strength of a connection terminal portion.

  In recent years, due to the spread of the Internet and the like, there has been a demand for an increase in the amount of information processing of personal computers and an increase in information processing speed. Increasing information transmission speed is required.

  A hard disk drive is a magnetic disk that is a magnetic recording medium, a spindle motor that rotates the magnetic disk at high speed, a magnetic head that reads or writes information on the magnetic disk, and each component that moves it while holding it with high precision. Drive control circuit and signal processing circuit.

  A component called a magnetic head suspension that supports a magnetic head used in this hard disk drive is generally called a so-called wireless suspension in which a signal line such as a copper wiring is formed directly on a stainless spring. Wiring integrated type (flexure) is adopted.

  Here, the wiring usually has a connection terminal portion for electrical connection with a magnetic head or an external circuit. Conventionally, a good electrical connection is made on the surface of the connection terminal portion. Therefore, a metal plating layer such as Ni (nickel) or Au (gold) is formed.

  In addition, as such connection terminal portions, so-called flying leads that are used not only on one side but also on both sides of a conductor pattern are becoming widespread in recent years in order to cope with higher density and downsizing of electronic and electrical devices. is there.

7 and 8 are explanatory views illustrating an example of the configuration of the connection terminal portion having a flying lead. FIG. 7 is a schematic plan view, and FIG. 8 is a cross-sectional view taken along line DD in FIG.
As shown in FIGS. 7 and 8, a metal support substrate 200 made of SUS or the like, a first insulating layer 300 formed on the metal support substrate 200, and a wiring formed on the first insulating layer 300 In the suspension flexure substrate including the layer 400 and the second insulating layer 500 that covers the wiring layer 400, the connection terminal portion 700 having the flying lead 450 opens the metal support substrate 200 and the first insulating layer 300. The back surface of the wiring layer 400 is exposed, the second insulating layer 500 is opened to expose the surface of the wiring layer 400, and a metal plating layer is provided on one or both sides of the exposed wiring layer 400 as necessary. Is formed.
And the connection terminal part 700 which has such a flying lead 450 is connected with an external terminal by applying ultrasonic vibration using a bonding tool etc., for example.

  However, in the connection terminal portion 700 having such a flying lead 450, since both surfaces of the wiring layer 400 are exposed, ultrasonic waves are easily transmitted and suitable for bonding by ultrasonic vibration, but physical strength. The edge of the opening of the first insulating layer 300 and the second insulating layer 500, that is, at the portion where the first insulating layer 300 and the second insulating layer 500 and the wiring layer 400 of the connection terminal portion intersect with the wiring layer 400 is weak. There is a problem that the stress is concentrated and the wiring layer 400 is easily disconnected.

  Therefore, as shown in FIG. 9, a suspension that ensures strength by increasing the width of the wiring layer 400 at a portion where the first insulating layer 300 and the second insulating layer 500 intersect with the wiring layer 400 of the connection terminal portion 700. A flexure substrate has been proposed (Patent Document 1).

  In addition, a method has been proposed in which an insulating film is formed on one side of the exposed surface of the wiring layer of the connection terminal portion, and the wiring layer of the connection terminal portion is reinforced by this insulating film to make it difficult to cut (Patent Document 2). ).

JP 2003-31915 A JP 2006-31764 A

  However, as described in Patent Document 1, in the method of increasing the width of the wiring layer at the opening edge of the connection terminal portion where the flying lead is formed, the interval between the wiring layers cannot be reduced, It is disadvantageous for miniaturization. In addition, since the distance between the wiring layers cannot be reduced, there is a problem in that the insulation reliability between the wiring layers cannot be maintained when the number of wirings increases in the future.

  Further, in the method of forming an insulating film on one side of the exposed surface of the wiring of the connection terminal portion as described in Patent Document 2, and reinforcing the wiring by this insulating film to make it difficult to cut, connection with an external terminal is possible. When applying ultrasonic vibration using a bonding tool, since there is an insulating film between the bonding tool and the wiring, the ultrasonic vibration is not directly transmitted to the wiring and the connection strength with the external terminal is ensured. The problem remains in connection reliability of maintaining.

  The present invention has been made in view of the above circumstances, and even when the wiring is miniaturized or densified, while ensuring the wiring strength of the connection terminal portion and effectively preventing disconnection, the external It is an object of the present invention to provide a suspension flexure substrate that can ensure connection reliability with a terminal.

  In order to solve the above problems, a flexure substrate for suspension according to the present invention includes a metal supporting substrate, an insulating layer on the metal supporting substrate, a wiring layer on the insulating layer, and an insulating layer and a protective layer on the wiring layer. A suspension flexure substrate, wherein one or both of the insulating layer and the protective layer is a wiring layer in a plan view around the connection terminal portion formed by opening the metal support substrate, the insulating layer, and the protective layer. And a receding region that does not exist in the region including the overlapping portion.

  Moreover, the flexure substrate for suspension according to the present invention is characterized in that the edge of one or both of the insulating layer and the protective layer is curved at the periphery of the receding region.

  In the flexure substrate for suspension according to the present invention, the area of the receding region of the protective layer in plan view is larger than the area of the receding region of the insulating layer.

  In the flexure substrate for suspension according to the present invention, the area of the receding region of the insulating layer in plan view is larger than the area of the receding region of the protective layer.

  The suspension flexure substrate according to the present invention is characterized in that the opening of the metal support substrate includes the opening of the insulating layer and a receding region in plan view.

  In the flexure substrate for suspension according to the present invention, the receding region is provided separately so as to overlap the side surface in the line width direction of the wiring layer in plan view.

  In the flexure substrate for suspension according to the present invention, both the insulating layer and the protective layer have the receding region, and at least a part of the receding region of the insulating layer and at least the receding region of the protective layer. A part thereof overlaps each other in plan view to form a through region penetrating in the stacking direction, and the through region exposes the side surface in the line width direction of the wiring layer.

  ADVANTAGE OF THE INVENTION According to this invention, it can relieve | moderate that the stress by the ultrasonic wave at the time of terminal connection concentrates on the specific part of a wiring layer, and can provide the flexure board | substrate for suspensions which a wiring layer does not disconnect or generate | occur | produce easily.

It is the schematic which shows an example of the flexure board | substrate for suspensions of this invention. It is an enlarged plan view which shows an example of the connection terminal part in the flexure board | substrate for suspensions of this invention. It is sectional drawing which shows an example of the connection terminal part in the flexure board | substrate for suspensions of this invention. It is a top view which shows the example of the shape of the retreat area | region in a connection terminal part. It is an enlarged plan view which shows the other example of the connection terminal part in the flexure board | substrate for suspensions of this invention. It is sectional drawing which shows the other example of the connection terminal part in the flexure board | substrate for suspensions of this invention. It is a top view which shows the connection terminal part in the conventional flexure board | substrate for suspensions. It is sectional drawing which shows the connection terminal part in the conventional flexure board | substrate for suspensions. It is a top view which shows the other form of the connection terminal part in the conventional flexure board | substrate for suspensions. It is the top view and sectional drawing explaining the manufacturing method of the flexure substrate for suspensions of this invention. It is the top view and sectional drawing explaining the process of following FIG. FIG. 12 is a plan view and a cross-sectional view illustrating a process following the process in FIG. 11. It is the top view and sectional drawing explaining the process of following FIG. FIG. 14 is a plan view and a cross-sectional view illustrating a process following the process in FIG. 13. It is the top view and sectional drawing explaining the process following FIG. FIG. 16 is a plan view and a cross-sectional view illustrating a process following the process in FIG. 15. FIG. 17 is a plan view and a cross-sectional view illustrating a process following the process in FIG. 16. FIG. 18 is a plan view and a cross-sectional view illustrating a process following the process in FIG. 17. It is the top view and sectional drawing explaining the process of following FIG. FIG. 20 is a plan view and a cross-sectional view illustrating a process following the process in FIG. 19. It is an enlarged plan view which shows the other example of the connection terminal part in the flexure board | substrate for suspensions of this invention. It is a top view which shows the example of the shape of the retreat area | region in the connecting terminal part shown in FIG. It is a top view which shows the other example of the shape of the retreat area | region in the connection terminal part shown in FIG. It is an enlarged plan view which shows the other example of the connection terminal part in the flexure board | substrate for suspensions of this invention. It is sectional drawing which shows the other example of the connection terminal part in the flexure board | substrate for suspensions of this invention. It is a top view which shows the example of the shape of the retreat area | region in the connection terminal part shown in FIG. It is a perspective view for demonstrating the analysis target object used in the Example of this invention. It is a perspective view for demonstrating the boundary condition of the analysis target object used in the Example of this invention. It is a figure for demonstrating the press conditions of the analysis target object used in the Example of this invention. It is a figure which shows the planar shape of the analysis target object (model 1) corresponding to the 2nd form of this invention. It is a figure which shows the planar shape of the analysis symmetry thing (model 2) corresponding to the 4th form of this invention. It is a figure which shows the planar shape of the analysis target object (model 3) as a comparative example.

  Hereinafter, the flexure substrate for suspension of the present invention will be described in detail.

FIG. 1A is a schematic plan view of a suspension flexure substrate according to the present invention, and FIG. 1B is a cross-sectional view taken along line XX in FIG. The flexure substrate 1 includes a metal support substrate 2, an insulating layer 3 provided on the metal support substrate 2, a wiring layer 4 provided on the insulating layer 3, and a protective layer 5 provided on the wiring layer 4. Have In FIG. 1A, since the wiring layer 4 is shown in a simplified manner, for example, the number of wiring layers in the XX section is shown as one, but the number of wirings is not limited to this. For example, FIG. As shown in (b), there may be two in the XX section, or a two-layer structure with two upper and lower portions.
One end of the wiring layer 4 is connected to the slider head installation region 6 and the other end is connected to the connection terminal portion 7. The connection terminal portion 7 is joined to a terminal of an external circuit by ultrasonic bonding.

FIG. 2 is an enlarged plan view of the vicinity of the connection terminal portion 7 in the first embodiment of the present invention.
2A is a plan view seen from the protective layer 5 side, and FIG. 2B is a plan view seen from the metal support substrate 2 side (or the insulating layer 3 side). 3A is a cross-sectional view taken along line AA in FIG. 2, and FIG. 3B is a cross-sectional view taken along line BB in FIG. 2 and 3, the connection terminal portion 7 is a region in which all of the metal support substrate 2, the insulating layer 3, and the protective layer 5 are opened. In this region, the front and back of the wiring layer 4 and the side surface 4a in the line width direction thereof. Is exposed. That is, for example, in FIG. 2B, a region X indicated by a broken line is the connection terminal portion 7. In the connection terminal portion 7, the wiring layer 4 forms a flying lead, and other metal layers such as gold plating are provided on one side or both sides as necessary in order to improve the connection with the terminal of the external circuit. You may do it.

  On the other hand, on the outer periphery of the connection terminal portion, the end portion 31 of the insulating layer 3 on the insulating layer 3 side of the wiring layer 4 is retreated in a direction away from the connection terminal portion, and a retreated region 80 is formed. In the receding region 80, the side surface of the wiring layer 4 is not exposed, but the surface on the insulating layer 3 side is exposed. In FIG. 2, in the protective layer 5, there is no part which the edge part 51 recedes in the direction away from a connection terminal part. Therefore, in the receding region 80, one surface of the wiring layer 4 is exposed, but the other surface and side surfaces are not exposed.

  2 and 3, the metal support substrate 2 is opened so as to include the connection terminal portion 7 and the receding region 80. This is to prevent the wiring layer 4 and the metal support substrate 2 from coming into contact with each other and short-circuiting when bonding the wiring layer 4 in the connection terminal portion 7.

FIG. 4 is an enlarged view of the receding region 80 and the vicinity thereof (region C in FIG. 2B). The shape of the end 31 of the receding region 80 (or the insulating layer 3) may be semicircular as shown in FIG. 4A, or a polygonal shape as shown in FIG. A trapezoidal shape as shown in c) or a rectangular shape as shown in FIG. Further, as shown in FIG. 4 (e), even if it has an end shape as shown in FIGS. 4 (a) to 4 (d) integrally over the wiring layer 4 and its vicinity. good. By making the end shape like this, the boundary line between the exposed portion and the unexposed portion of the wiring layer 4 can be made long, and the wiring layer 4 is connected to the wiring of the external circuit by ultrasonic bonding. Sometimes, stress concentration on the end portion 31 of the insulating layer due to ultrasonic bonding can be alleviated, and occurrence of defects such as disconnection or deformation of the wiring layer 4 can be suppressed. In FIG. 4, it is preferable that the receding region 80 has an end shape that does not have a vertex as shown in FIG. 4A or a shape that has a large interior angle of the vertex as shown in FIG. 4B. If there is no vertex as shown in FIG. 4A, stress concentration at the vertex can be avoided. If the interior angle of the vertex is large as shown in FIG. 4B, the stress concentration at the vertex is This is because it becomes very small. The receding length L of the receding region 80 (the maximum length of the receding region 80 in the direction orthogonal to the line width direction of the wiring layer 4) is not particularly limited, but is 0.5% of the line width of the wiring layer 4. About 2 times is preferable.
If the receding length L of the receding region 80 is too small with respect to the line width of the wiring layer 4, the effect of making the wiring layer 4 difficult to break or deform is hardly exhibited. This is because the exposed portion becomes large and the wiring layer 4 is likely to be deteriorated, and the deterioration of conductivity and the adverse effect on impedance control can be considered. Although the line width of the wiring layer 4 is not specifically limited, For example, the range of 10 micrometers-200 micrometers is mentioned. If the line width of the wiring layer 4 is too small, the conductivity may be deteriorated. If the line width of the wiring layer 4 is too large, the suspension flexure substrate may not be sufficiently densified. Because.

FIG. 5 is an enlarged plan view of the vicinity of the connection terminal portion 7 in the second embodiment of the present invention.
5A is a plan view seen from the protective layer 5 side, and FIG. 5B is a plan view seen from the metal support substrate 2 side (or the insulating layer 3 side). 6A is a cross-sectional view taken along line AA in FIG. 5, and FIG. 6B is a cross-sectional view taken along line BB in FIG. In FIG. 5 and FIG. 6, the same reference numerals are given to portions common to FIG. 2 and FIG. In the present embodiment, the end portion 51 of the protective layer 5 on the protective layer 5 side of the wiring layer 4 is retreated in the direction away from the connection terminal portion on the outer periphery of the connection terminal portion, and a retreat region 81 is formed. .

  Further, in this embodiment, as shown in FIG. 6, the position of the end 31 of the insulating layer 3 and the position of the end 51 of the protective layer 5 do not coincide on the wiring layer 4. This is because the stress concentration is alleviated by shifting the positions of the end portions of the insulating layer 3 and the protective layer 5. 5 and 6, the area of the portion where the insulating layer 3 does not exist is larger than the area of the portion where the protective layer 5 does not exist, but the area of the portion where the protective layer 5 does not exist is larger than the area of the insulating layer 3. It may be larger than the area of the portion where no exists. However, when ultrasonic bonding is performed, a relatively large stress is applied to the wiring layer 4 on the insulating layer 3 side. Therefore, as shown in FIGS. 5 and 6, the end 31 of the insulating layer 3 in the receding region is It is preferable to form the protective layer 5 so as to be farther from the connection terminal portion 7 than the end portion 51 of the protective layer 5 because the risk of disconnection and deformation of the wiring layer 4 can be reduced.

  The shape of the end portion 51 of the receding region 81 (or the protective layer 5) may be formed in the same manner as the shape of the end portion 31 of the insulating layer 3 described in the first embodiment. Further, the shape of the end 51 of the protective layer 5 and the shape of the end 31 of the insulating layer 3 may be the same or different.

  FIG. 21 is an enlarged plan view of the vicinity of the connection terminal portion 7 in the third embodiment of the present invention. 21A is a plan view seen from the protective layer 5 side, and FIG. 21B is a plan view seen from the metal support substrate 2 side (or the insulating layer 3 side). FIG. 22 is an enlarged view of the receding region 80 and its vicinity (region C in FIG. 2B). 21 and 22, the same reference numerals are given to portions common to FIGS. 2 and 3, and description thereof is omitted. In the present embodiment, the receding region 80 is provided separately on the outer periphery of the connection terminal portion so as to overlap the line width direction side surface 4a of the wiring layer 4 in plan view. That is, two receding regions 80 are provided in the region C shown in FIG. 2B, and each receding region 80 is formed across the wiring layer 4 and the vicinity thereof. Thereby, the stress applied to the wiring layer 4 can be more effectively reduced over the line width direction of the wiring layer 4.

  In FIG. 21, the protective layer 5 has no portion where the end portion 51 recedes in the direction away from the connection terminal portion 7. Therefore, in the receding region 80, one surface of the wiring layer 4 is exposed, but the other surface is not exposed. Further, as shown in FIG. 22, the edge 55 a orthogonal to the wiring layer 4 of the opening 55 of the protective layer 5 is connected to the connection terminal portion 7 from the edge 35 a orthogonal to the wiring layer 4 of the opening 35 of the insulating layer 3. It is formed in the direction to go away. This is to relieve stress concentration. The edge 55a of the protective layer 5 is formed in a direction away from the connection terminal portion 7 from the edge 35a of the insulating layer 3, so that a part of the side surface 4a in the line width direction of the wiring layer 4 is exposed in the receding region 80. ing.

  As shown in FIG. 22, an insulating layer residual portion 37 of the insulating layer 3 is formed between the wiring layers 4 adjacent to each other on the outer periphery of the connection terminal portion 7. Thereby, the strength of the insulating layer 3 that supports the connection terminal portion 7 is secured. In addition, since each receding region 80 is interposed between the portion of the insulating layer 3 on the wiring layer 4 and the insulating layer residual portion 37, the occurrence of defects such as disconnection or deformation of the wiring layer 4 is further suppressed. can do.

  Moreover, what is necessary is just to form the shape of the edge part 31 of each receding area | region 80 similarly to the shape of the edge part 31 of the insulating layer 3 described in the 1st form. Thereby, the boundary line between the part where the wiring layer 4 is exposed and the part where the wiring layer 4 is not exposed can be made long. When the wiring layer 4 is connected to the wiring of the external circuit by ultrasonic bonding, the insulating layer 3 by ultrasonic bonding is used. It is possible to alleviate the concentration of stress on the end portion 31 and to suppress the occurrence of defects such as disconnection or deformation of the wiring layer 4.

  In the form shown in FIGS. 21 and 22, as shown in FIG. 23, each receding region 80 has its edge on the wiring layer 4 side overlapping the line width direction side surface 4 a of the wiring layer 4 in plan view. The wiring layer 4 may be formed on the side of the wiring layer 4 from the side surface 4a in the line width direction. In this case, the receding region is formed in the vicinity of the wiring layer 4, and the edge of the receding region 80 on the wiring layer 4 side is formed so as to be continuous with the side surface 4a in the line width direction of the wiring layer 4 in plan view. The stress concentration of the layer 4 can be further relaxed.

  FIG. 24 is an enlarged plan view of the vicinity of the connection terminal portion 7 in the fourth embodiment of the present invention. 24A is a plan view seen from the protective layer 5 side, and FIG. 24B is a plan view seen from the metal support substrate 2 side (or the insulating layer 3 side). 25A is a cross-sectional view taken along line AA in FIG. 24, and FIG. 25B is a cross-sectional view taken along line BB in FIG. FIG. 26 is an enlarged view of the receding region 80 and the vicinity thereof (region C in FIG. 2B). 24 to 26, the same reference numerals are given to portions common to FIGS. 21 and 22, and the description thereof is omitted. In the present embodiment, the end portion 51 of the protective layer 5 on the protective layer 5 side of the wiring layer 4 is retreated in the direction away from the connection terminal portion on the outer periphery of the connection terminal portion, and a retreat region 81 is formed. . The receding region 81 is provided separately so as to overlap the line width direction side surface 4a of the wiring layer 4 in plan view. That is, two receding regions 80 and two receding regions 81 are provided in the region C shown in FIG. Thereby, the stress applied to the wiring layer 4 can be more effectively reduced over the line width direction of the wiring layer 4.

  A part of the receding region 80 of the insulating layer 3 and a part of the receding region 81 of the protective layer 5 corresponding to each other overlap each other in plan view, thereby forming a through region 85 penetrating in the stacking direction. Each penetrating region 85 exposes the corresponding side 4a of the wiring layer 4 in the line width direction. Thereby, in the receding regions 80 and 81 corresponding to each other, the side surface 4a in the line width direction of the wiring layer 4 is exposed, the surface on the insulating layer 3 side and the surface on the protective layer 5 side are exposed, and stress on the wiring layer 4 is exposed. Is more relaxed.

  In this embodiment, as shown in FIGS. 25 and 26, the position of the end 31 of the insulating layer 3 and the position of the end 51 of the protective layer 5 do not coincide on the wiring layer 4. This is because the stress concentration is alleviated by shifting the positions of the end portions of the insulating layer 3 and the protective layer 5. In the outer periphery of the connection terminal portion 7, the area of the portion where the insulating layer 3 does not exist is smaller than the area of the portion where the protective layer 5 does not exist, but the area of the portion where the protective layer 5 does not exist It may be smaller than the area of the part where 3 does not exist.

  As shown in FIG. 26, the protective layer residual portion 57 of the protective layer 5 is formed between the wiring layers 4 adjacent to each other on the outer periphery of the connection terminal portion 7. Thereby, the intensity | strength of the protective layer 5 which supports the connection terminal part 7 is ensured. In addition, since each receding region 81 is interposed between the protective layer 5 portion on the wiring layer 4 and the protective layer residual portion 57, the occurrence of defects such as disconnection and deformation of the wiring layer 4 is further suppressed. can do.

What is necessary is just to form the shape of the edge part 51 of the retreat area | region 81 (or protective layer 5) similarly to the shape of the edge part 31 of the insulating layer 3 described in the 1st form and the 3rd form. Further, the shape of the end 51 of the protective layer 5 and the shape of the end 31 of the insulating layer 3 may be the same or different. Further, similarly to the receding region 80 shown in FIG. 23, the receding regions 80 and 81 shown in FIG. 24 to FIG. 26 have the edge on the wiring layer 4 side overlapping the line width direction side surface 4 a of the wiring layer 4 in plan view. The wiring layer 4 may be formed on the side of the wiring layer 4 from the side surface 4a in the line width direction.
Further, the entire receding region 80 of the insulating layer 3 and the corresponding receding region 81 of the protective layer 5 may form the penetrating region 85.

  Next, a method for manufacturing a flexure substrate for suspension according to the present invention will be described.

  10 to 20 are views showing an example of a manufacturing method of the suspension flexure substrate of the first embodiment. 10 to 20, (a) is a plan view seen from the upper surface (protective layer side) of the flexure substrate, (b) is a plan view seen from the lower surface (metal support substrate side) of the flexure substrate, and (c) is It is AA sectional drawing (sectional drawing in the part used as a wiring layer) in (a) and (b).

  First, as shown in FIG. 10, a substrate material 9 including a metal supporting substrate 2, an insulating layer 3, a seed layer 40 and a metal plating layer 41 is prepared. The metal support substrate 2 is preferably a SUS material, but is not particularly limited as long as it has a desired rigidity. Examples of the insulating layer 3 include polyimide. However, the insulating layer 3 is not particularly limited as long as it has insulating properties. Examples of the seed layer 40 include nickel (Ni), chromium (Cr), and copper (Cu) formed by sputtering, but are not particularly limited as long as the metal plating layer 41 can be formed on the layer. . The seed layer 40 is a layer that forms the wiring layer 4 integrally with the metal plating layer 41 after the wiring layer 4 is formed.

  Next, as shown in FIG. 11, resist layers 90 and 91 are formed so as to cover the metal plating layer 41 and the metal support substrate 2, respectively, and further patterned. Examples of the method for forming the resist layers 90 and 91 include a method of laminating a dry film resist and a method of applying a liquid resist by a method such as spin coating or slit coating. As a patterning method for the resist layers 90 and 91, for example, a so-called photolithography method in which a resist is exposed using a photomask on which a desired pattern is formed and then developed is used. By the patterning, a portion of the resist layer 90 where the wiring layer 4 is not formed is removed, and a portion of the resist layer 91 where the metal support substrate 2 is opened is removed.

  Next, as shown in FIG. 12, the wiring layer 4 is formed by performing chemical etching on the portion of the seed layer 40 and the metal plating layer 41 where the resist layer 90 is not present. Chemical etching is also performed on the portion where the resist layer 91 does not exist, so that the metal support substrate opening 25 is formed. After the etching, the resists 90 and 91 are peeled off (FIG. 13).

  Next, as shown in FIG. 14, the protective layer 5 is formed so as to cover the insulating layer 3 and the wiring layer 4. Although the same material as the insulating layer 3 can be used for the protective layer 5, it is not limited to this.

Next, as shown in FIG. 15, a resist layer 92 is formed so as to cover the surface on the protective layer 5 side, and a resist layer 93 is formed so as to cover the surface on the metal support substrate side, and further patterning is performed.
A method similar to the method for forming the resist layers 90 and 91 described above can be applied to the method for forming the resist layers 92 and 93 and the patterning method. Here, the pattern shape of the resist layer 92 is a rectangular pattern straddling a plurality of wiring layers 4 (metal plating layers 41) arranged in parallel in a plan view, and a semicircular pattern connected to the outer periphery of the rectangular pattern on each wiring layer 4 Are connected continuously. By patterning, a portion of the resist layer 92 where the protective layer 5 is opened is removed.

  Next, as shown in FIG. 16, a portion of the protective layer 5 where the resist layer 92 is not formed is removed, and then the resist layer 92 and the resist layer 93 are removed (FIG. 17). As a method for removing the protective layer 5, for example, when the protective layer 5 is formed of a polyimide material, etching with an organic alkaline solution or plasma etching may be used. The shape of the protective layer opening 55, which is a portion from which the protective layer 5 has been removed, includes a rectangular pattern straddling a plurality of wiring layers 4 (metal plating layers 41) arranged in parallel in a plan view, and a rectangular pattern on each wiring layer 4 The semicircular pattern connected to the outer periphery of the substrate is continuously connected, and the insulating layer 3 and the wiring layer 4 are exposed.

  Next, as shown in FIG. 18, a resist layer 94 is formed so as to cover the surface on the protective layer 5 side, and a resist layer 95 is formed so as to cover the surface on the metal supporting substrate 2 side, and further patterning is performed. . The formation method and patterning method of the resist layers 94 and 95 are the same as the formation method and patterning method of the resist layers 90 to 93 described above. Here, the pattern shape is a rectangular pattern straddling a plurality of wiring layers 4 (metal plating layers 41) arranged in parallel in plan view, and a semicircular pattern connected to the outer periphery of the rectangular pattern on each wiring layer 4 is continuous. Keep the shape connected. Further, the insulating layer opening 35 (see FIG. 20) after the insulating layer 3 is opened has a larger area in plan view than the protective layer opening 55, or after the insulating layer 3 is opened. The insulating layer opening 35 has an area smaller than that of the protective layer opening 55 in plan view. That is, the end 31 of the insulating layer 3 and the end 51 of the protective layer 5 do not coincide with each other on the wiring layer 4 in the plan view. Furthermore, the area of the insulating layer opening 35 is made smaller than that of the metal support substrate opening 25 in plan view. By patterning, the portion of the resist layer 94 where the insulating layer 3 is opened is removed.

  Next, as shown in FIG. 19, a portion of the insulating layer 3 where the resist layer 94 is not formed is removed. As a method for removing the insulating layer 3, for example, when the insulating layer 3 is formed of a polyimide material, the same method as described in the method for removing the protective layer 5 can be used.

  Next, as shown in FIG. 20, the resist layer 94 and the resist layer 95 are removed, and the flexure substrate for suspension according to the present invention is obtained.

  The manufacturing method of the suspension flexure substrate according to the present invention has been described above, but the manufacturing method is not limited to this.

  Hereinafter, the present invention will be described more specifically with reference to examples.

  A metal support substrate made of SUS material, an insulating layer made of polyimide, a seed layer made of a sputtering layer of nickel (Ni), chromium (Cr), copper (Cu), and a metal plating layer made of a copper plating layer Laminated substrate materials were prepared, and a dry film resist was bonded to both sides thereof. Subsequently, the dry film resist was patterned by exposure and development. The patterning shape was a wiring pattern shape on the metal plating layer side and a rectangular shape including the connection terminal portion on the metal support substrate side. Thereafter, the metal plating layer and the metal supporting substrate were etched using ferric chloride solution, and the seed layer where the exposed metal plating layer was removed was removed. As a result, a wiring layer was formed on the insulating layer, and a rectangular opening was formed in the metal support substrate.

Subsequently, a protective layer made of polyimide was formed on the surface on which the wiring layer was formed, and a resist was formed so as to cover it. A resist was also formed on the surface of the metal support substrate.
Next, the resist was subjected to patterning by exposure and development. The resist pattern on the protective layer side is continuously connected by a rectangular pattern having the same center position as the opening of the metal support substrate and a semicircular pattern connected to the outer periphery of the rectangular pattern on each wiring layer. And a shape having a smaller area than the opening of the metal support substrate. Thereafter, the protective layer was etched using an organic alkali solution. As a result, the connection terminal portion and the receding region of the surface on the protective layer side of the wiring layer were exposed.

  Subsequently, a resist was formed so as to cover the surface on the protective layer side and the surface on the metal support substrate side, and patterning by exposure and development was performed on the resist. The resist pattern on the metal support substrate side consists of a rectangular pattern having the same center position as the opening of the metal support substrate and a semicircular pattern connected to the outer periphery of the rectangular pattern on each wiring layer. The shape was connected, and the area was smaller than the opening of the metal support substrate. In addition, the end of the semicircular pattern connected to the outer periphery of the rectangular pattern on each wiring layer is more than the center position of the rectangular pattern than the end of the protective layer located on the opposite side through the wiring layer. I tried to be far away. Thereafter, the insulating layer was etched using an organic alkali solution. As a result, the front and back surfaces were exposed in part of the wiring layer, and flying leads were formed. Thereafter, the surface of the wiring layer on the side connected to the external circuit was gold-plated to obtain a flexure substrate for suspension in the present invention.

  Next, as an example, a simulation when the wiring layer 4 is pressed with a bonding tool from the metal support substrate 2 side will be described with reference to FIGS. 27 to 32. As shown in FIG. 27, the analysis target in the simulation is that the flying leads of the wiring layer 4 are halved in the longitudinal direction and halved in the width direction. The length in the Z direction of the metal supporting substrate 2 in the analysis target shown in FIG. 27 is 100 μm, and the length in the X direction of the insulating layer 3 is 250 μm. 28A is a front view of the analysis target as viewed from the arrow E in FIG. 27, and FIG. 28B is a side view of the analysis target as viewed from the arrow F in FIG. It is. For the sake of clarity, the retracted region is omitted in FIGS.

  As shown in FIG. 28A, the metal support substrate 2, the insulating layer 3, the wiring layer 4, and the protective layer 5 were fixed in the X direction by the fixing portion S in consideration of the periodic symmetry. Further, as shown in FIG. 28B, the tip portion of the wiring layer 4 to be analyzed is fixed in the Z direction by the fixing portion S assuming that there is no displacement in the Z direction. Further, the metal support substrate 2 to be analyzed is fixed in the Y direction by the fixing portion S in consideration of the fact that it is originally supported by the surface plate, and the metal support substrate 2, the insulating layer 3, the wiring layer 4, and the protection The Z direction was fixed by the fixing portion S in consideration of the fact that the base end portion of the layer 5 was originally structured.

  In the analysis, in order to simulate that the wiring layer 4 is pressed by the bonding tool, a state in which a predetermined range on the tip side of the wiring layer 4 is displaced by 10 μm in the Y direction as shown in FIG. As shown in FIG. 29, the distance between the edge of the range in which this displacement was applied and the edge 35a of the insulating layer opening 35 (see FIG. 26, etc.) was 50 μm. The thickness of the metal support substrate 2 was 18 μm, the thickness of the insulating layer 3 was 10 μm, the thickness of the wiring layer 4 was 9 μm, and the thickness of the protective layer 4 on the wiring layer 4 was 4 μm.

  The analysis includes a model 1 corresponding to the second embodiment of the present invention shown in FIGS. 5 and 6, a model 2 corresponding to the fourth embodiment of the present invention shown in FIGS. 24 to 26, and a model 1 as a comparative example. Alternatively, the test was performed on the model 3 in which the receding regions 80 and 81 were removed from the model 2. In model 1, the planar shape viewed from the metal support substrate 2 side as shown in FIG. 30 is reflected in the analysis model shown in FIG. 27, and in model 2, the plane viewed from the metal support substrate 2 side as shown in FIG. The shape was reflected in the analysis model. In the model 3, the planar shape viewed from the metal support substrate 2 side as shown in FIG. 32 is reflected in the analysis model. The unit of the dimension shown in FIGS. 30 to 32 is μm.

Table 1 shows the maximum stress generated in the wiring layer 4 by analyzing in this way.

  As shown in Table 1, it was confirmed that the maximum stress was reduced in the models 1 and 2 compared to the model 3. Thus, it can be seen that by providing the receding regions 80 and 81, stress concentration on the wiring layer 4 when the wiring layer 4 is pressed by a bonding tool or the like can be alleviated.

  In addition, said embodiment is an illustration and this invention is not limited to said embodiment. That is, the present invention can be applied to the connection terminal portion 7 of the suspension flexure substrate 1 in FIG. 1, for example, in the slider head grounding region 6, the suspension flexure substrate 1 and the slider head (not shown). The present invention can also be applied to terminals that are electrically connected to the terminal. In other words, a device having substantially the same configuration as the technical idea described in the claims of the present invention and having the same function and effect is included in the technical scope of the present invention in any case. Is done.

DESCRIPTION OF SYMBOLS 1 ... Flexure substrate for suspension 2 ... Metal support substrate 3 ... Insulation layer 4 ... Wiring layer 4a ... Line width direction side surface 5 ... Protective layer 6 ... Slider head installation area 7 ... Connection terminal part 9 ... Substrate material 25 ... Metal support substrate opening Part 31 ... End part (of insulating layer) 35 ... Insulating layer opening part 35a ... Edge 37 ... Insulating layer residual part 40 ... Seed layer 41 ... Metal plating layer 51 ... End part (of protective layer) 55 ... Protective layer opening part 55a ... Edge 57 ... Protective layer remainder 80 ... Recessed area (on insulating layer side) 81 ... Recessed area (on protective layer side) 85 ... Through area 90 ... Resist layer 91 ... Resist layer 92 ... Resist layer 93 ... Resist layer 94 ... Resist layer 95 ... Resist layer 200 ... Metal substrate 300 ... Insulating layer 400 ... Wiring layer 450 ... Flying lead 500 ... Protective layer 700 … Connection terminal L… Retraction length

Claims (6)

A suspension flexure substrate having a metal support substrate, an insulating layer on the metal support substrate, a wiring layer on the insulating layer, and a protective layer on the insulating layer and the wiring layer,
The metal support substrate, the insulating layer, and the protective layer are all open, and have a connection terminal portion in which the front and back of the wiring layer and the side surface in the line width direction are exposed,
Wherein in the vicinity of the connection terminal portion, bi towards the insulating layer and the protective layer, it has a retraction area that does not exist in a region including a portion overlapping with the wiring layer in plan view,
The receding region is provided separately so as to overlap the side surface in the line width direction of the wiring layer in plan view,
At least a part of the receding region of the insulating layer and at least a part of the receding region of the protective layer form a penetrating region penetrating in the stacking direction by overlapping each other in plan view;
A flexure substrate for suspension , wherein the through region exposes the side surface in the line width direction of the wiring layer . A suspension flexure substrate having a metal support substrate, an insulating layer on the metal support substrate, a wiring layer on the insulating layer, and a protective layer on the insulating layer and the wiring layer,
The metal support substrate, the insulating layer, and the protective layer are all open, and have a connection terminal portion where the front and back of the wiring layer and the side surface in the line width direction are exposed,
A suspension flexure substrate characterized in that, around the connection terminal portion, the insulating layer has a receding region that does not exist in a region including a portion overlapping the wiring layer in plan view.   The suspension flexure substrate according to claim 2, wherein the protective layer has a receding region that does not exist in a region including a portion overlapping with the wiring layer in a plan view around the connection terminal portion. In the periphery of the backward area, wherein the ends of one or both of the layers of the protective layer and the insulating layer is curved, flexible substrate for suspension according to claim 1 or 3. The area of the backward area of the insulating layer in a plan view, being greater than the area of the backward area of the protective layer, flexible substrate for suspension according to any one of claims 1, 3 and 4 . The opening of the metal support substrate in plan view includes the opening of the insulating layer in the connection terminal portion and the receding region, according to any one of claims 1 to 5 . Flexure substrate for suspension.