Patent Application
20110063816
The present application claims priority from Japanese Patent Application No. 2009-215977 filed on Sep. 17, 2009, the content of which is hereby incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a wired circuit board, a connection structure thereof, and a connection method therefor. More particularly, the present invention relates to a wired circuit board suitably used for connection of a suspension board with circuit and a relay flexible wired circuit board, a connection structure thereof, and a connection method therefor.
2. Description of Related Art
Conventionally, a suspension board with circuit mounted on a hard disk drive has been connected to a control circuit board through a relay flexible wired circuit board, and relay terminals of the suspension board with circuit and suspension terminals of the relay flexible wired circuit board have been connected via bumps.
In the connection described above, the suspension board with circuit and the relay flexible wired circuit board have been known to be arranged so that their planes are orthogonal to each other.
There has been proposed, for example, that in the above-mentioned construction and arrangement, a cutout cut in a semicircular arc shape in plan view is formed in the center of each relay terminal (cf. Japanese Unexamined Patent Publication No. 2006-165268).
In Japanese Unexamined Patent Publication No. 2006-165268, a hemispherical bump is formed in a surface of each suspension terminal, and the bumps are then fitted into the cutouts of the relay terminals, thereby achieving reduction in size.
However, the relay terminals of Japanese Unexamined Patent Publication No. 2006-165268 is required to have cutouts formed, which is time-consuming and troublesome. Therefore, the manufacturing process may become complicated.
Further, the contact between the bumps and the cutouts becomes insufficient, which may result in insufficient connection between the relay terminals and the suspension terminals.
It is an object of the present invention to provide a wired circuit board that can allow simple and secure connection between a first terminal and a second terminal even if a first wired circuit board and a second wired circuit board are arranged so that a first plane and a second plane are intersected with each other.
The wired circuit board of the present invention includes a first wired circuit board provided with a first conductive pattern which has a first terminal comprising placement surface for placing a meltable metal and a first wire continuous with the first terminal; and a second wired circuit board provided with a second conductive pattern which has a second terminal connected with the first terminal through the meltable metal and a second wire continuous with the second terminal, in which the first wired circuit board and the second wired circuit board are arranged so that a first plane containing the first terminal and a second plane containing the second terminal are intersected with each other, and the placement surface is zoned so as to gradually widen toward the second terminal.
In the wired circuit board of the present invention, it is preferable that the first wired circuit board includes an insulating cover layer which covers the first wire and exposes the first terminal, and the first terminal is formed so as to gradually widen toward the second terminal, whereby the placement surface is zoned so as to gradually widen toward the second terminal.
In the wired circuit board of the present invention, it is preferable that the first wired circuit board includes an insulating cover layer which covers the first wire and partially exposes the first terminal, and the placement surface is zoned so as to gradually widen toward the second terminal by being exposed from the insulating cover layer so as to gradually widen toward the second terminal.
In the wired circuit board of the present invention, it is preferable that the placement surface is zoned in a generally trapezoidal shape when projected in a thickness direction of the first wired circuit board.
In the wired circuit board of the present invention, it is preferable that the placement surface is zoned in a generally triangular shape when projected in a thickness direction of the first wired circuit board.
The connection structure of the wired circuit boards of the present invention include a first wired circuit board provided with a first conductive pattern which has a first terminal comprising a placement surface for placing a meltable metal and a first wire continuous with the first terminal; and a second wired circuit board provided with a second conductive pattern which has a second terminal connected with the first terminal through the meltable metal and a second wire continuous with the second terminal, in which the first wired circuit board and the second wired circuit board are arranged so that a first plane containing the first terminal and a second plane containing the second terminal are intersected with each other, the placement surface is zoned so as to gradually widen toward the second terminal, and the first terminal and the second terminals connected through the meltable metal.
The method for connecting the wired circuit boards of the present invention includes the steps of preparing a first wired circuit board provided with a first conductive pattern which has a first terminal including a placement surface zoned so as to gradually widen outward and a first wire continuous with the first terminal; preparing a second wired circuit board provided with a second conductive pattern which has a second terminal and a second wire continuous with the second terminal; placing a meltable metal on the placement surface of the first terminal; arranging the first wired circuit board and the second wired circuit board so that the first plane including the first terminal and the second plane including the second terminal are intersected with each other; and connecting the first terminal and the second terminal through the meltable metal by melting the meltable metal.
In the wired circuit board of the present invention, the placement surface of the first terminal is zoned so as to gradually widen toward the second terminal.
Therefore, in the method for connecting the wired circuit board of the present invention, when the meltable metal is placed on the placement surface and then melted, the meltable metal is unevenly distributed toward the second terminal. That is, the meltable metal is formed to be gradually thicker toward the second terminal.
The first wired circuit board and the second wired circuit board are arranged so that the first plane and the second plane are intersected with each other, thereby allowing the second terminal to contact over a wide contact area with a thickened portion of the meltable metal.
Therefore, the connection between the first terminal and the second terminal through the meltable metal, and further, the connection between the first wired circuit board and the second wired circuit board can be secured.
Since the first terminal is formed with simple construction, even if the first wired circuit board and the second wired circuit board are arranged so that the first plane and the second plane are intersected with each other, the first terminal and the second terminal can be easily connected.
Furthermore, since the meltable metal is formed to be gradually thicker toward the second terminal, the meltable metal can contact the second terminal even if the amount of the metal used for formation of the meltable metal is reduced by such thickened amount. Therefore, cost can be reduced.
To clearly illustrate a relative position of a first conductive pattern 4, a first insulating cover layer 5 described later is omitted in
In
As shown in
As shown in
As shown in
The first conductive pattern 4 integrally has a suspension terminal 7 as a first terminal, an external terminal 8, and a first wire 6 electrically connected between the suspension terminal 7 and the external terminal 8.
The suspension terminal 7 is arranged in the front end portion (one lengthwise end portion) of the relay flexible wired circuit board 2, and a plurality (six pieces) of the suspension terminals 7 are arranged in parallel at spaced intervals to each other along a widthwise direction (a direction orthogonal to the lengthwise direction).
Specifically, as shown in
The leading edges of the suspension terminals 7 are arranged in the same position as the leading edge of the first insulating base layer 3 as viewed in plane and are flush with the leading edge thereof in the thickness direction.
As shown in
Specifically, each of the external terminals 8 is formed in a generally rectangular shape (a square land) in plan view extending in the lengthwise direction. The trailing edges of the suspension terminals 7 are arranged at spaced intervals to the trailing edge of the first insulating base layer 3 and are parallel thereto.
The first wire 6 extends in the lengthwise direction and a plurality (six pieces) of the first wires 6 are arranged in parallel at spaced intervals to each other along the widthwise direction. The first wires 6 are formed so that their front ends are continuous with the trailing edges of the suspension terminals 7 and that their rear ends are continuous with the leading edges of the external terminals 8.
As shown in
Specifically, in the widthwise direction, the first insulating cover layer 5 covers the upper surface of the first insulating base layer 3, and the upper surfaces and both widthwise side surfaces of the first wires 6: Further, in the lengthwise direction, the first insulating cover layer 5 is formed slightly shorter than the first insulating base layer 3, and exposes the suspension terminals 7 and the external terminals 8.
That is, the front end portion of the first insulating cover layer 5 exposes the lengthwise centers and the front end portions of the plurality of suspension terminals 7, and covers the rear end portions thereof. The leading edge of the first insulating cover layer 5 is linearly formed along the widthwise direction, and is arranged on the rear side at a region where the lengthwise centers and the front end portions of the suspension terminals 7 are arranged, away from the leading edge of the first insulating base layer 3.
Although not shown in
In the relay flexible wired circuit board 2, each suspension terminal 7 has a placement surface 9 for placing a first bump 12 as a meltable metal.
As shown in
In order to obtain the relay flexible wired circuit board 2, a first insulating base layer 3 is first prepared.
The insulating materials that may be used for forming the first insulating base layer 3 include, for example, synthetic resins such as polyimide resin, polyamide imide resin, acrylic resin, polyether nitrile resin, polyether sulfone resin, polyethylene terephthalate resin, polyethylene naphthalate resin, and polyvinyl chloride resin. Of these resins, polyimide resin is preferably used.
The first insulating base layer 3 is formed in the following manner. For example, a varnish of photosensitive resin (photosensitive polyamic acid resin) is coated over the entire upper surface of a support plate which is not shown. Thereafter, the coated varnish is exposed to light via a photomask and then developed. Subsequently, the resulting product is heated to be dried and cured, to thereby forming a first insulating base layer 3.
The first insulating base layer 3 thus formed has a thickness in the range of, for example, 5 to 20 μm, or preferably 7 to 15 μm.
Then, a first conductive pattern 4 is formed on the first insulating base layer 3.
The conductive materials that may be used for forming the first conductive pattern 4 include, for example, copper, nickel, gold, or alloys thereof. Of these, copper is preferably used.
The first conductive pattern 4 is formed into the above-mentioned pattern by a known patterning method, such as an additive method or a subtractive method.
The first conductive pattern 4 thus formed has a thickness in the range of, for example, 3 to 50 μm, or preferably 5 to 20 μm.
Each of the first wires 6 has a width (length in widthwise direction) in the range of, for example, 2 to 200 μm, or preferably 5 to 100 μm. The spacing (spacing in widthwise direction) between each of the first wires 6 ranges, for example, from 2 to 200 μm, or preferably from 5 to 100 μm.
The suspension terminals 7 and the external terminals 8 each have a length (length in lengthwise direction) in the range of, for example, 50 to 2000 μm, or preferably 150 to 1000 μm.
The trailing edge of the suspension terminal 7 has substantially the same width as the first wire 6. The leading edge of the suspension terminal 7 has a larger width than the trailing edge thereof, and specifically, has a width of, for example, 125 μm or more, preferably 150 μm or more, or more preferably 250 μm or more, and usually 1000 μm or less. The spacing between the suspension terminals 7 ranges, for example, from 20 to 100 μm, or preferably from 30 to 50 μm at the trailing edge, and from 2 to 20 μm, or preferably from 5 to 10 μm at the leading edge.
The trailing edge of the placement surface 9 has a width of, for example, more than 50 μm, or preferably 100 μm, and less than 250 μm, or preferably less than 150 μm.
In each of the suspension terminals 7, an angle α which is formed between both widthwise opposite edges thereof ranges, for example, from 20 to 120 degrees, or preferably from 40 to 90 degrees.
The width of each of the external terminals 8 and the spacing between them range, for example, from 20 to 800 μm, or preferably from 30 to 500 μm.
Next, a first insulating cover layer 5 is formed on the first insulating base layer 3 so as to cover the first conductive pattern 4.
The insulating materials that may be used for forming the first insulating cover layer 5 include the same materials as those used for forming the first insulating base layer 3 as described above.
The first insulating cover layer 5 is formed in the following manner. For example, a varnish of photosensitive resin (photosensitive polyamic acid resin) is coated over the upper surfaces of the first insulating base layer 3 and the first conductive pattern 4. Thereafter, the coated varnish is exposed to light via a photomask and then developed. Subsequently, the resulting product is heated to be dried and cured, to thereby forming a first insulating cover layer 5.
The first insulating cover layer 5 thus formed has a thickness in the range of, for example, 5 to 20 μm, or preferably 7 to 15 μm.
Thereafter, the support plate is removed by peeling or etching.
Thus, the relay flexible wired circuit board 2 is obtained.
As shown in
As shown in
As shown in
As shown in
As shown in
The head terminal 27 is arranged in the front end portion of the suspension board with circuit 21, and a plurality (six pieces) of the head terminals 27 are arranged in parallel at spaced intervals to each other along the widthwise direction.
Specifically, each of the head terminals 27 is formed in a generally rectangular shape (a square land) in plan view extending in the lengthwise direction. The leading edges of the head terminals 27 are arranged at spaced intervals to the leading edge of the metal supporting board 22 and are parallel thereto.
The relay terminal 28 is arranged in one widthwise end of the rear end portion of the suspension board with circuit 21, and is arranged along one widthwise edge of the rear end portion of the suspension board with circuit 21.
Specifically, a plurality (six pieces) of the relay terminals 28 are arranged in parallel at spaced intervals to each other along the lengthwise direction, and each formed in a generally rectangular shape (a square land) in plan view extending in the widthwise direction. The trailing edges (one widthwise edges) of the relay terminals 28 are arranged at spaced intervals to one widthwise edge of the metal supporting board 22.
As shown in
As shown in
Specifically, partway in the lengthwise direction, the second insulating cover layer 25 covers the upper surface (surface) of the second insulating base layer 23, and the upper surfaces (surfaces) and both widthwise side surfaces of the second wires 26. Although not shown in
As shown in
In order to obtain this suspension board with circuit 21, as shown in
The metal materials that may be used for forming the metal supporting board 22 includes, for example, stainless steel, 42-alloy, aluminum, copper-beryllium, and phosphor bronze. Of these, a stainless steel is preferably used.
The metal supporting board 22 has a thickness in the range of, for example, 15 to 50 μm, or preferably 20 to 30 μm.
Next, a second insulating base layer 23 is formed on the metal supporting board 22.
The insulating materials that may be used for forming the second insulating base layer 23 include the same materials as those used for forming the first insulating base layer 3 as described above.
The second insulating base layer 23 is formed in the following manner. For example, a varnish of photosensitive resin (photosensitive polyamic acid resin) is coated over the entire upper surface of the metal supporting board 22. Thereafter, the coated varnish is exposed to light via a photomask and then developed. Subsequently, the resulting product is heated to be dried and cured, to thereby forming a second insulating base layer 23.
The second insulating base layer 23 thus formed has a thickness in the range of, for example, 5 to 20 μm, or preferably 7 to 15 μm.
Next, a second conductive pattern 24 is formed on the second insulating base layer 23.
The conductive materials that may be used for forming the second conductive pattern 24 include the same materials as those used for forming the first conductive pattern 4 as described above.
The second conductive pattern 24 is formed into the above-mentioned pattern by a known patterning method, such as an additive method or a subtractive method.
The second conductive pattern 24 thus formed has a thickness in the range of, for example, 3 to 50 μm, or preferably 5 to 20 μm.
Each of the second wires 26 has a width in the range of, for example, 2 to 100 μm, or preferably 5 to 50 μm. The spacing between each of the second wires 26 is in the range of, for example, 2 to 100 μm, or preferably 5 to 50 μm.
Each of the length (length in lengthwise direction) of the head terminal 27 and the length (length in widthwise direction) of the relay terminal 28 is in the range of, for example, 200 to 5000 μm, or preferably 500 to 2000 μm.
Each of the width (length in widthwise direction) of the head terminal 27 and the width (length in lengthwise direction) of the relay terminal 28 each is in the range of, for example, 20 to 800 μm, or preferably 30 to 500 μm.
Each of the spacing (spacing in lengthwise direction) between the head terminals 27 and the spacing (spacing in widthwise direction) between the relay terminals 28 is in the range of, for example, 20 to 800 μm, or preferably 30 to 500 μm.
Next, a second insulating cover layer 25 is formed on the second insulating base layer 23 so as to cover the second conductive pattern 24.
The insulating materials that may be used for forming the second insulating cover layer 25 include the same materials as those used for forming the first insulating base layer 3 as described above.
The second insulating cover layer 25 is formed in the following manner. For example, a varnish of photosensitive resin (photosensitive polyamic acid resin) is coated over the upper surfaces (surfaces) of the second insulating base layer 23 and the second conductive pattern 24. Thereafter, the coated varnish is exposed to light via a photomask and then developed. Subsequently, the resulting product is heated to be dried and cured, to thereby forming a second insulating cover layer 25.
The second insulating cover layer 25 thus formed has a thickness in the range of, for example, 5 to 20 μm, or preferably 7 to 15 μm.
Thus, the suspension board with circuit 21 is obtained.
Next, a method for connecting between the relay flexible wired circuit board 2 and the suspension board with circuit 21 is described with reference to
First, in this method, as shown in
Subsequently, in this method, as shown in phantom line in
The materials that may be used for the first bumps 12 include, for example, alloys (solder alloy) made of at least two or more kinds selected from tin, indium, silver, copper, zinc, lead, gold, antimony, and bismuth. Of these, a tin alloy containing tin is preferably used. A cream solder containing the above-mentioned solder alloy can also be used.
The first bumps 12 are placed by a printing method such as a screen printing method of printing cream solder at a temperature lower than the melt temperature of the first bump 12.
The first bumps 12 thus placed are formed into a generally semicircular or semi-elliptical cross sectional shape.
Each of the first bumps 12 has a height of, for example, 20 to 500 μm, and the bottom surface thereof has a diameter (maximum length) of, for example, 40 to 1000 μm.
As shown in phantom line in
The materials used for the second bumps 13 include the same materials as those used for the first bumps 12 as described above. Besides, the placement method of the second bumps 13 is the same as that used for the first bumps 12 as described above. As shown in phantom line in
Next, in this method, as shown in
As shown in phantom line in
Further, the second plane 11 is a plane which spreads along the second conductive pattern 24 in the suspension board with circuit 21.
Accordingly, the suspension board with circuit 21 is arranged in opposed relation to the front side of the relay flexible wired circuit board 2 so that the first plane 10 and the second plane 11 are orthogonal to each other. More particularly, the suspension board with circuit 21 is arranged at an angle of generally 90 degrees at spaced intervals to the relay flexible wired circuit board 2 on the front side of the relay flexible wired circuit board 2.
Thus, the first bump 12 and the second bump 13 are arranged in opposed relation to each other.
Next, in this method, the first bumps 12 placed on the placement surfaces 9 and the second bumps 13 placed on the surfaces of the relay terminals 28 are melted.
The first bumps 12 and the second bumps 13 are melted by heating the first bumps 12 and the second bumps 13 at a temperature higher than their melt temperature by a heating method such as laser (Xe lamp laser) irradiation or using a soldering iron. Preferably, the first bumps 12 and the second bumps 13 are heated by laser radiation.
Immediately after the heating (or at the same time of heating, i.e., while the first bumps 12 and the second bumps 13 are being melted), the first bumps 12 and the second bumps 13 are brought into contact with each other as shown in
In order to bring the first bump 12 and the second bump 13 into contact with each other, the relay flexible wired circuit board 2 and the suspension hoard with circuit 21 are moved (slided) closer to each other as indicated by the arrow in
Thus, the suspension terminals 7 and the relay terminals 28 are connected to each other through the first bumps 12 and the second bumps 13.
The external terminals 8 (see
In this wired circuit board 1, the placement surfaces 9 of the suspension terminals 7 are zoned so as to gradually widen toward the front side.
Therefore, in the connection between the relay flexible wired circuit board 2 and the suspension board with circuit 21 as described above, when the first bumps 12 are placed on the placement surfaces 9 and then melted, the first bumps 12 are unevenly distributed toward the front side, as shown in
That is, each of the first bumps 12 is formed to be gradually thicker toward the front side. More specifically, each of the first bumps 12 is formed into a generally drop-shaped cross-section or a streamlined half-split shape having a gravity center on the front side.
Then, the relay flexible wired circuit board 2 and the suspension board with circuit 21 are arranged so that the first plane 10 and the second plane 11 are orthogonal to each other, whereby the second bumps 13 formed on the surfaces of the relay terminals 28 can contact over a wide contact area with thickened portions of the first bumps 12.
Therefore, the connection between the suspension terminals 7 and the relay terminals 28 through the first bumps 12 and the second bumps 13, and further, the connection between the relay flexible wired circuit board 2 and the suspension board with circuit 21 can be secured.
The suspension terminals 7 are formed with a simple construction each having a generally trapezoidal shape in plan view. Therefore, even if the relay flexible wired circuit board 2 and the suspension board with circuit 21 are arranged so that the first plane 10 and the second plane 11 are intersected with each other, the suspension terminals 7 and the relay terminals 28 can be easily connected.
Further, since the first bumps 12 placed on the placement surfaces 9 are formed to be gradually thicker toward the front side, the first bumps 12 can contact the relay terminals 28 even if the amount of the material used for formation of the first bumps 12 is reduced by such thickened amount. Therefore, cost can be reduced.
Furthermore, since the amount of the material used for the formation of the first bumps 12 is reduced, the first bumps 12 can be formed compactly. Therefore, a short circuit of adjacent suspension terminals 7 caused by a contact between the first bumps 12 in the widthwise direction can be prevented effectively.
In the relay flexible wired circuit board 2, since the leading edge of the first insulating cover layer 5 is linearly formed, the first insulating cover layer 5 can be formed with a simple construction.
In the above explanation, the upper surface of each second bump 13 is formed in a curved shape. However, for example, as indicated by dashed lines in
The upper surfaces (the smooth surfaces) of the second bumps 13 are formed in parallel to the second plane 11.
The smoothing surfaces of the second bumps 13 are formed in the following manner. After the second bumps 13 are placed on the relay terminals 28, before the second bumps 13 are located closer to the first bumps 12, the curved upper surfaces of the second bumps 13 are subjected to smoothing processing, for example, by pressing process (crushing work) using pressure. In this case, the melt-heating process of the second bumps 13 can be omitted.
In the above explanation, the second bumps 13 are formed on the surfaces of the relay terminals 28. However, for example, though not shown, the suspension terminals 7 and the relay terminals 28 may be connected through the first bumps 12, without forming the second bumps 13 on the surfaces of the relay terminals 28.
Thus, cost can be further reduced.
In the above explanation, the suspension terminals 7 and the relay terminals 28 are moved closer to each other immediately after the melting of the first bumps 12 and the second bumps 13. However, for example, though not shown, the suspension terminals 7 and the relay terminals 28 are preliminarily arranged closely to each other and the first bumps 12 and the second bumps 13 are then melted to be in contact with each other, so that the suspension terminals 7 and the relay terminals 28 can be connected with each other.
This method can eliminate the need for moving (sliding) of the relay flexible wired circuit board 2 closer to the suspension board with circuit 21 after the melting of the first bumps 12 and the second bumps 13. Therefore, the suspension terminals 7 and the relay terminals 28 can be more easily connected with each other.
In the above explanation, the first bumps 12 are placed by the printing method conducted at a temperature lower than the melt temperature of the first bumps 12. However, for example, the first humps 12 may be placed by a heat coating method of heating the first bumps 12 at a temperature higher than the melt temperature of the first bumps 12, such as flow.
In such case, each of the first bumps 12 thus placed is formed to already be gradually thicker toward the front side as shown in
In other words, after the first bump 12 is placed on the placement surface 9, the shape of the first bump 12 before melting for connection between the suspension terminals 7 and the relay terminals 28 is substantially the same as that after the melting for the connection described above.
The same reference numerals are provided in each of the subsequent figures for members corresponding to each of those described above, and their detailed description is omitted.
In the above explanation, the suspension terminal 7 is formed in a generally trapezoidal shape in plan view. However, the shape thereof is not particularly limited, and the suspension terminal 7 may be formed into, for example, a generally trapezoidal shape having a generally right angle as shown in
In
The other widthwise edge of each of the suspension terminals 7 is inclined relative to one widthwise edge thereof so as to be gradually spaced away from one widthwise edge thereof toward the front side.
The angle β between the other widthwise edge and one widthwise edge is, for example, 20 degrees or more and less than 90 degrees, or preferably 40 degrees or more and less than 90 degrees.
In
In
More specifically, each of the suspension terminals 7 includes a front portion 31 having a generally trapezoidal shape in plan view narrowing toward the front side, and a rear portion 32 having a generally trapezoidal shape in plan view continuously formed on the rear side of the front portion 31.
The leading edge of the front portion 31 is arranged in the same position as the leading edge of the first insulating base layer 3. Both widthwise edges of the front portion 31 are formed so as to become closer to each other toward the front side.
The rear portion 32 is formed in a generally trapezoidal shape in plan view gradually widening toward the front side. Both widthwise edges of the rear portion 32 are formed so as to be gradually spaced away from each other toward the front side.
The length of the front portion 31 is formed shorter than that of the rear portion, so that the gravity center of each of the suspension terminals 7 exists on the front side.
The trailing edge of the rear portion 32 is covered with the leading edge of the first insulating cover layer 5.
The surface of the front portion 31, and the surfaces of the lengthwise center and the front end portion of the rear portion 32 serve as the placement surface 9. Since the trailing edge of the rear portion 32 is covered with the first insulating cover layer 5, the placement surface 9 in the rear portion 32 is formed in a generally trapezoidal shape gradually widening toward the front side.
In
In the above explanation, in the relay flexible wired circuit board 2, the leading edge of the first insulating cover layer 5 is linearly formed along the widthwise direction. However, for example, as shown in
In
The leading edge of the first insulating cover layer 5 is formed in a sawtooth shape in plan view, and specifically, has cutouts 14 formed by cutting the first insulating cover layer 5 rearwardly corresponding to each of the suspension terminals 7.
Each of the cutouts 14 is formed in a generally trapezoidal shape in plan view gradually widening toward the front side. The size (size in plan view, i.e., length and spacing) of each cutout 14 is the same as that of the suspension terminal 7 shown in
In the first insulating cover layer 5, the leading edge other than the cutouts 14 is arranged in the same position as the leading edge of the first insulating base layer 3 as viewed in plane.
Thus, the cutouts 14 partially expose the placement surfaces 9 of the suspension terminals 7 in the above-mentioned generally trapezoidal shape in plan view.
In other words, the placement surfaces 9 of the suspension terminals 7 are exposed from the cutouts 14 of the first insulating cover layer 5 so as to be in a generally trapezoidal shape in plan view gradually widening toward the front side, and the surfaces (specifically, both edges of the rear end portion) other than the placement surfaces 9 in the suspension terminals 7 are covered with the first insulating cover layer 5.
Thus, the placement surfaces 9 are zoned by the cutouts 14 in the first insulating cover layer 5 so as to gradually widen toward the front side.
The first bumps 12 placed on the placement surfaces 9 serve as weirs by which the cutouts 14 in the first insulating cover layer 5 prevent the first bumps 12 from moving rearward during melting for connection between the suspension terminals 7 and the relay terminals 28. Therefore, the first bumps 12 can be more securely in contact with the second bumps 13 to achieve further secure connection between the suspension terminals 7 and the relay terminals 28.
In the above explanation, the placement surface 9 is zoned into a generally trapezoidal shape. However, for example, as shown in
In
Thus, the placement surfaces 9 of the suspension terminals 7 are exposed from the cutouts 14 in the first insulating cover layer 5 so as to be in a generally trapezoidal shape in plan view gradually widening toward the front side.
Then, in the relay flexible wired circuit board 2 shown in
On the other hand, in the relay flexible wired circuit board 2 shown in
While the illustrative embodiments of the present invention are provided in the above description, such is for illustrative purpose only and it is not to be construed limitative. Modification and variation of the present invention that will be obvious to those skilled in the art is to be covered by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-215977 | Sep 2009 | JP | national |
