JP4691805B2 - Wire cutting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wire cutting device .
[0002]
[Prior art]
Wire bonding is widely used as a method for electrically connecting a semiconductor element to a circuit electrode of a substrate. In this wire bonding, the wire is gripped by a chuck, which is an electrode of a wire bonding apparatus, and the end surface of the wire is pressed against a bonded object such as an external connection electrode of a semiconductor element, and electricity is conducted and melted. Welded with objects. Bonding is performed by moving the wire in this state to a desired connection point such as a circuit electrode of the substrate by moving the chuck. In such a bonding operation, since the wire is supplied as a continuous line, it is necessary to cut the wire for each bonding operation. Further, by this cutting, the wire is cut so that the wire slightly protrudes from the chuck so that the next bonding can be performed.
[0003]
In the conventional wire cutting device, a pair of cutting tools 41 having a cutting edge with an acute angle like a pliers, as shown in FIG. 4A and FIG. And a device that cuts by cutting the pair of cutting tools 43 like a scissors (Fig. 4 (b)). Etc.
[0004]
However, in the pliers-type device, as shown in FIG. 4A, the cut surface of the wire 45 has a raised ridge shape at the center, so that the wire end surface is pressed against the joint to conduct electricity as in wire bonding. In the case of melting and welding, the welding conditions are not stable, and there is a problem that a good welding state cannot be obtained.
[0005]
In addition, in the saddle type apparatus, as shown in FIG. 4B, a portion near the cut surface of the wire 47 is pushed and bent by the cutting tool 43 after cutting, and the tip position of the wire 47 is shifted. There is a problem that it becomes difficult to press the end face of 47 to a desired joining position.
[0006]
[Problems to be solved by the invention]
This invention is made | formed in view of the said problem, and provides the wire cutting device which can be cut | disconnected so that there may be no bending of the wire after a cutting | disconnection and a cut surface may become a plane.
[0007]
[Means for Solving the Problems]
The present invention provides, as means for solving the above-mentioned problems, a wire cutting device described in each claim.
[0008]
According to the first aspect of the present invention, the stopping means for stopping the rotational movement of the first cutting member toward the wire at the position in contact with the wire and the load means for applying a load to the rotational movement of the second cutting member toward the wire. The first cutting member is rotated and moved first, the wire to be cut is stopped by the stopping means, and then the second cutting member is rotated and moved to intersect the first cutting member. By this, a cutting process of cutting the wire by applying a shearing force is realized. According to the first aspect of the present invention, at the time of cutting, the first cutting member is attached so as to be positioned closer to the gripping means than the second cutting member. The portion to be touched is supported by the first cutting member on the gripping means side. In this state, the second cutting member is crossed on the side farther from the gripping means of the first cutting member and shearing is applied to the wire to cut the wire. In addition, the front end portion can be held at the positioned position, and the cut surface can be cut to be a flat surface. As a result, in wire bonding, since the cut surface is flat, the welding conditions are stable and a good welded state can be obtained, and the end of the wire (cut surface) since the cut surface is held at the positioned position. Alignment to a desired joining position becomes easy.
[0009]
In addition , since the driving means is rotatably attached to the base member, the driving means is automatically adjusted in its direction according to the relationship between the stopping means and the load means, and the first cutting member and the second cutting member. Therefore, the step of operating the second cutting member and cutting the wire after positioning by the first cutting member as described above is realized without adding a complicated power transmission mechanism.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or similar components are denoted by common reference numerals.
[0011]
FIG. 1 is a top view of a wire cutting device 1 according to an embodiment of the present invention. In FIG. 1, 3 is a base part, 5 is a 1st cutting member, 7 is a 2nd cutting member, 15 shows a drive means.
[0012]
As shown in FIG. 1, the first cutting member 5 is a substantially rod-like member as a whole, and has a mounting projection 6 having a mounting hole (not shown) at the center thereof, and penetrates the mounting hole in the vertical direction. The mounting pin 13 is attached to the base portion 3 so as to be rotatable in the horizontal direction. The first cutting member 5 has a cutting edge portion 9 at one end thereof, and the cutting edge portion 9 is provided with a notch for receiving a wire during cutting. The other end of the first cutting member 5 is attached to a power transmission unit 21 that is a part of the driving means 15. The second cutting member 7 has substantially the same configuration as the first cutting member 5, and is provided at the central portion thereof in the same manner as the first cutting member 5 so as to face the first cutting member 5. The mounting protrusions 8 (not shown) of the mounting protrusions 8 are attached to the base portion 3 so as to be rotatable in the horizontal direction by mounting pins 13 penetrating in the vertical direction. Moreover, the cutting blade part 11 is provided also in the one end part of the 2nd cutting member 7, and this cutting blade part 11 also has a notch for receiving a wire at the time of a cutting | disconnection. The other end of the second cutting member 7 is attached to a power transmission unit 21 that is a part of the driving means 15, similarly to the first cutting member 5. In addition, in this embodiment, the 1st cutting member 5 and the 2nd cutting member 7 turn the base part 3 downward, the 2nd cutting member 7 is located on the base part 3, and on the 2nd cutting member 7 It attaches so that the 1st cutting member 5 may be located. That is, when the cutting members 5 and 7 are rotated so that the cutting blade portion 9 of the first cutting member 5 and the cutting blade portion 11 of the second cutting member 7 intersect each other, the cutting blade of the first cutting member 5 The part 9 is positioned above the cutting edge part 11 of the second cutting member 7.
[0013]
In the present embodiment, as shown in FIG. 1, the drive unit 15 includes a drive unit 20 and a power transmission unit 21 attached to the drive part of the drive unit 20. Is rotatably attached to the base portion 3 at the opposite side portion. The drive unit 20 linearly expands and contracts the drive part connected to the power transmission unit 21 to reciprocate. In addition, as shown in FIG. 1, the power transmission unit 21 includes three short rod-shaped members, that is, a first member 23, a second member 25, and a third member 27 at one end of each member and at one end of the other two members. It is configured to be rotatably mounted. The other ends of the first member 23, the second member 25, and the third member 27 are attached to the drive portion of the drive unit 20, the end of the first cutting member 5, and the end of the second cutting member 7, respectively. At this time, the end portions of the second member 25 and the first cutting member 5 and the end portions of the third member 27 and the second cutting member 7 are rotatably attached, respectively. By setting it as such a structure, it becomes possible to rotationally move the 1st cutting member 5 and the 2nd cutting member 7 by the linear movement of the drive part of the drive part 20. As shown in FIG.
[0014]
The wire cutting device 1 of the present embodiment is further provided with a stopping means 17 and a load means 19.
[0015]
The stopping means 17 is such that the first cutting member 5 is driven by the action of the driving means 15 so that the cutting edge portion 9 of the first cutting member 5 approaches the cutting edge portion 11 of the second cutting member 7, that is, the wire to be cut In some cases, when rotating in the direction toward the wire, when the rotational movement reaches a predetermined position, it contacts the first cutting member 5 and serves to limit the rotational movement. As shown in FIG. 1, in this embodiment, the stopping means 17 is a stopping means extending substantially perpendicular to the upper plane of the base portion 3 to which the first cutting member 5 and the second cutting member 7 are attached. It is a bolt-shaped member 17 attached to the attachment wall 16, and comes into contact with the first cutting member 5 at a portion of the first cutting member 5 on the side of the driving means 15 on the side opposite to the attachment projection 6. It is arranged. By rotating and moving the bolt-shaped member 17, the contact position with the first cutting member 5 can be changed, and the stop position of the cutting edge portion 9 of the first cutting member 5 can be adjusted.
[0016]
On the other hand, the load means 19 cuts the second cutting member 7 in the direction in which the cutting blade portion 11 of the second cutting member 7 approaches the cutting blade portion 9 of the first cutting member 5, that is, by the action of the driving means 15. When there is a wire, when it is going to rotate and move in the direction toward the wire, the rotation of the second cutting member 7 is applied until the driving force to apply the load and to move the rotation reaches a predetermined value. Plays the role of preventing movement. As shown in FIG. 1, in this embodiment, the load means 19 is a load means extending substantially perpendicular to the upper plane of the base portion 3 to which the first cutting member 5 and the second cutting member 7 are attached. A spring member 19 is mounted between the mounting wall 18 and a portion of the second cutting member 7 opposite to the mounting projection 8 and closer to the drive means 15 than the center. As the load means 19, any appropriate elastic member other than the spring member can be used.
[0017]
Further, as shown in FIG. 1, on the upper plane of the base portion 3, there are a portion on the driving means 15 side from the center of the first cutting member 5 and a portion on the driving means 15 side from the center of the second cutting member 7. A stop member 29 is provided in between. When the drive portion of the drive means 15 contracts and the cutting blade portion 9 of the first cutting member 5 and the cutting blade portion 11 of the second cutting member 7 rotate and move away from each other, the center of the first cutting member 5 The portion closer to the drive means 15 and the portion closer to the drive means 15 than the center of the second cutting member 7 abut against the stop member 29, and the rotational movement stops at a predetermined position.
[0018]
Next, with reference to FIG.2 and FIG.3, the action | operation of the wire cutting device 1 of this embodiment is demonstrated. FIG. 2 is a top view showing the operation of the wire cutting device 1 in the series of wire 31 cutting steps. FIGS. 2A, 2B, and 2C are a start stage and a positioning stage, respectively. Shows the cutting stage. FIG. 3 is a view when the cutting process of the wire 31 by the wire cutting device 1 is viewed from the attachment pin 13 toward the end of the two cutting members 5 and 7 having the cutting blade portions 9 and 11. Yes, as in FIG. 2, FIGS. 3 (a), 3 (b), and 3 (c) correspond to a start stage, a positioning stage, and a cutting stage, respectively. In each drawing of FIG. 3, the cutting blade portions 9 and 11 are shown in a cross section taken at the center of each notch. In the present embodiment, the wire 31 to be cut is gripped downward in the vertical direction by a chuck 33 as gripping means located above the wire cutting device 1 as shown in each drawing of FIG. Yes.
[0019]
2 (a) and 3 (a), the drive portion of the drive unit 20 of the drive means 15 is in a contracted state, and the cutting blade portions 9 of the two cutting members 5, 7 are provided. 11 is the most separated state, and the wire 31 held by the chuck 33 is between the two cutting blade portions 9 and 11. At this stage, neither cutting edge portion 9 or 11 is in contact with the wire 31.
[0020]
The cutting process starts when the drive portion of the drive unit 20 of the drive means 15 extends from this starting stage. When extension of the drive part of the drive part 20 starts, the action of the power transmission part 21 causes each of the cutting members 5 and 7 to approach the two cutting members 5 and 7 in the direction in which the cutting blade parts 9 and 11 approach each other, that is, A force to rotate in the direction toward the wire 31 to be cut acts. However, since the load means 19 acts on the second cutting member 7 as described above, no rotational movement occurs, and only the first cutting member 5 is present at the initial stage of extension of the drive portion of the drive unit 20. Will rotate. At this time, since the second cutting member 7 does not move due to the action of the load means 19 even though the driving portion is extended, the driving means 15 changes its direction so as to rotate slightly toward the first cutting member 5 side. As shown in FIG. 2B, the rotation of the first cutting member 5 is a portion of the first cutting member 5 on the side of the driving means 15 from the center on the side opposite to the mounting projection 6 of the first cutting member 5. The process continues until the stop means 17 comes into contact. As shown in FIGS. 2 (b) and 3 (b), the stopping means 17 causes the cutting blade portion 9 of the first cutting member 5 to come into contact with the wire 31 as shown in FIGS. 31 is adjusted to stop at a position for positioning the chuck 31 on the central axis of the chuck 33.
[0021]
When the drive portion of the drive unit 20 is further extended from the positioning stage shown in FIGS. 2B and 3B, the first cutting member 5 abuts against the stop means 17 and cannot move further. The driving force for rotating the second cutting member 7 increases, and the second cutting member 7 starts to rotate against the load of the load means 19. At this time, the driving means 15 rotates back to the second cutting member 7 side and changes its direction. As a result of the rotational movement of the second cutting member 7, as shown in FIG. 2C and FIG. 3C, the cutting blade of the first cutting member 5 that contacts the wire 31 and positions the wire 31 Under the portion 9, that is, on the side far from the chuck 33, the cutting blade portion 11 of the second cutting member 7 crosses the wire 31 gripped in the vertical direction in the horizontal direction, and the wire 31 is cut by the shearing force. The
[0022]
By performing the cutting process as described above, the wire 31a on the side gripped by the chuck 33 is not bent even after cutting, and the tip portion can be held on the center axis of the chuck 33 positioned. At the same time, the cut surface can be a plane perpendicular to the central axis of the wire 31a (FIG. 3C). Moreover, in the wire cutting device 1 of this embodiment, the stop means 17 for stopping the rotational movement of the first cutting member 5 toward the wire 31 at the position in contact with the wire 31 and the wire 31 of the second cutting member 7 are directed. A load means 19 for applying a load to the rotational movement is provided, and the drive means 15 is rotatably attached to the base member 3, so that no complicated power transmission mechanism is added and only one drive means 15 is used. Then, after the positioning by the first cutting member 5 as described above, the second cutting member 7 operates to cut the wire.
[0023]
As is clear from the above description, according to the present embodiment, the first cutting member 5 is attached so as to be positioned closer to the gripping means 33 than the second cutting member 7 when the wire 31 is cut. First, by providing the stopping means 17 for stopping the rotational movement of the member 5 toward the wire 31 at a position in contact with the wire 31 and the load means 19 for applying a load to the rotational movement of the second cutting member 7 toward the wire 31, The first cutting member 5 rotates and positions the wire 31 that is stopped and cut by the stopping means 17 on the central axis of the chuck 33, and then the second cutting member 7 rotates and moves the first cutting member 5. On the side far from the chuck 33, a cutting process is realized in which the wire 31 is cut by applying a shearing force by perpendicularly intersecting the wire 31 gripped in the vertical direction. Even after cutting, the wire 31a on the side gripped by the chuck 33 is not bent, and its tip is held on the center axis of the positioned chuck 33, and the cut surface is a plane perpendicular to the center axis of the wire 31a. It can be. As a result, in wire bonding, since the cut surface is flat, the welding conditions are stable and a good welding state is obtained, and the cut surface is held on the center axis of the chuck 33 positioned, so that the end of the wire 31a Positioning of the part (cut surface) to a desired joining position becomes easy.
[Brief description of the drawings]
FIG. 1 is a top view of a wire cutting device according to an embodiment of the present invention.
2 is a top view showing the operation of the wire cutting device of FIG. 1 in a series of wire cutting steps, FIG. 2 (a), FIG. 2 (b), and FIG. 2 (c), respectively. A start stage, a positioning stage, and a cutting stage are shown.
3 is a view when the wire cutting process by the wire cutting device of FIG. 1 is viewed from the mounting pin side of both cutting members; FIG. 3 (a), FIG. 3 (b) and FIG. 3 (c) correspond to a start stage, a positioning stage, and a cutting stage, respectively.
4A and 4B are diagrams showing a state of wire cutting by a conventional wire cutting device, in which FIG. 4A shows cutting by a pliers-type cutting device, and FIG. 4B shows cutting by a scissors-type cutting device. .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Wire cutting device 3 ... Base part 5 ... 1st cutting member 6 ... Mounting projection part 7 ... Second cutting member 8 ... Mounting projection part 9 ... Cutting blade part 11 ... Cutting blade part 13 ... Mounting pin 15 ... Driving means 16 ... stopping means mounting wall 17 ... stopping means 18 ... load means mounting wall 19 ... load means 20 ... drive part 21 ... power transmission part 23 ... first member 25 ... second member 27 ... third member 29 ... stop member 31 ... wire 33 ... Chuck

Claims (2)

A base member, a first cutting member and a second cutting member that are rotatably attached to the base member, and a driving means for rotating the first cutting member and the second cutting member. In the wire cutting device for cutting the gripped wire,
The first cutting member is attached so as to be positioned closer to the gripping means than the second cutting member when the wire is cut, and the first cutting member and the second cutting member have a cutting edge portion at one end thereof. And connected to the driving means at the other end,
The drive means is a drive unit that linearly reciprocates the drive part, the drive part that is rotatably attached to the base member at a part opposite to the drive part, a first member, a second member, A power transmission unit composed of three members, wherein each member is rotatably attached to one end of the other two members at one end thereof, and the other end of the first member is attached to a drive portion of the drive unit. The other end of the second member is rotatably attached to the other end of the first cutting member, and the other end of the third member is rotatably attached to the other end of the second cutting member; Have
Stop means for stopping the rotational movement of the first cutting member toward the wire at a position in contact with the wire, and load means for applying a load to the rotational movement of the second cutting member toward the wire, the second cutting member Load means provided between a portion attached to the base member and the other end of the second cutting member, and after the first cutting member is stopped by the stopping means, A wire cutting device, wherein the wire is cut by a rotational movement of the second cutting member toward the wire.   The wire cutting device according to claim 1, wherein the load means is formed of an elastic member.

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