JP3123659B2 - Bending mold for electrical component leads - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to bending of leads for electric parts and the like. More specifically, IC, L
The present invention relates to a lead bending die of an electric component for Z-bending an end of an SI lead.

[0002]

2. Description of the Related Art The shape of an LSI package is a conventional DIP.
(Dual Inline Package) From the center, a method of electrically connecting a component or a device package with a lead wire to a conductor on the surface of a printed wiring board without using mounting holes for inserting a lead wire in recent years. Moving to surface mounting. This shift is to cope with an increase in the number of gates due to the high density, multifunction, and high speed of the LSI chip. Among the surface mounts, resin-sealed S
OJ (small outline j lead) and PLCC (plastic led chip)
carrier is known and used. Since the leads used in these are processed into a J-shape or an L-shape, they can be directly mounted on a printed wiring board (PWB).

[0003] Bending of lead wires of ICs is usually performed by pressing. Since the lead wire is extremely thin, the lead wire is easily damaged and requires careful attention in bending. Hereinafter, a conventional bending method performed by the inventor will be specifically described with reference to FIGS. The LSI package 60 is supplied to the fixed die 80 by a robot hand or a workpiece supply device (not shown), and is placed in a depression 81 provided on the die 80. At this time, the LSI package 6
The root portion 64 of the zero lead 65 is placed on the pressing protrusion 52 provided on the outer periphery of the depression 81. Next, by driving a press machine (not shown) to lower the punch 70 and pressing it from the root portion 64 of the lead 65, the lead 65 is bent into an approximately Z-shape as shown in FIG. is there.
Accordingly, the leads 65 are formed on the side surface 83 and the upper surface 84 of the pressing projection 82 of the die 80 and the side surface 71 and the lower surface 7 of the punch 70.
2 and pressed into a substantially Z-shape.
Bending is performed.

By the way, the leads 65 are plated with solder or tin to improve the conductivity when mounted on a printed wiring board (PWB) and the adhesion of solder during connection. In the conventional Z-bending method, the surface portion of the lead 65 comes into contact with a part of the surface of the punch 70 and the portions b and d are wrung, that is, subjected to burnishing. For this reason, dent marks are left on the portions a and c, and scratches due to frictional contact are left on the portions b and d. In extreme cases,
The plating of the lead 65 may peel off. By the way,
In recent years, in SO and QFP type LSI packages, the pitch between leads is 0.3 to 0.8 mm, and the length of leads is 1 to
3 mm, which is extremely thin, thin and short. When mounting an LSI package on a printed wiring board, even if only one of the many leads has such a dent or abrasion, if the plating is peeled off, the leads will float from the printed wiring board and the whole product will be defective. is there.

[0005] The stripping of the lead plating is also troublesome in another sense. That is, soft metal such as peeled tin adheres to the punches and dies of the mold. This acts as a resistance, and acts as a pulling force on the leads in the directions of e and f (see FIG. 9), thereby tearing the thin internal gold wire 62 bonded between the IC chip 61 and the lead frame 63. In some cases, the mold 66 may have cracks, so-called microcracks g.

Therefore, conventionally, in order to remove the sticking of the metal of the lead 65 to the punch 70 and the die 50, the bending mold is once removed from the press machine, and then these troubled materials are manually removed. I was doing something. For this reason, the life of the bending mold has been shortened and the cost has been increased.

[0007]

SUMMARY OF THE INVENTION The present invention has been intensively researched and developed to solve the above-mentioned problems, and achieves the following objects.

An object of the present invention is to provide a bending mold for a lead of an electric component which does not adversely affect a component body such as an LSI chip.

It is another object of the present invention to provide a bending mold for a lead of an electric component which performs a bending process without causing plating peeling due to dent marks or scratches on the lead.

Still another object of the present invention is to provide a bending die for a lead of an electric component having a long bending die life.

[0011]

Means for Solving the Problems To solve the above-mentioned problems, the following means are adopted.

The first means consists of an upper mold (10) and a lower mold (3).
0) The bending mold (1) for a lead of an electric component comprising the following requirements. a. The upper die (10) attached to the ram of a press machine
A punch holder (5) forming a part of b. An elastic support member (15) is provided on the punch holder (5).
By the first cam surface (2).
A movable stripper (17) formed with 3,3) for fixing the electrical component; c. The punch holder (5) is provided movably in a direction perpendicular to the vertical movement direction,
And a movable punch having a second cam surface (21, 22) for contacting the first cam surface (23, 24) and creating a locus for bending along with the vertical movement. (18), d. A die holder (2) constituting a part of the lower mold (30); e. A die (3) provided on the die holder (2) for mounting and fixing the electric component and having a third cam surface (34, 35) formed thereon; f. The lead (6) is cooperated with the movable punch (18).
A fourth cam surface (32, 33) for gripping the tip of 5) and forming a trajectory for the bending by contacting the third cam (34, 35) is formed. And a movable die (31) provided in the die (3).
And g. There is a pressing means (44) for pressing the movable die (31) to grip the lead (65) in cooperation with the movable punch (18).

[0013] It is preferable to have a temporary stopping means (42) for temporarily stopping the operation of the pressing means (44).

It is further preferred that the temporary stop means is a piston (42) which is operated by fluid pressure.

[0015]

[0016]

[0017]

[0018]

[0019]

[Operation] The operation of the bending die 1 for lead bending of an electric component will be described below. First, LSI on die 3
The package 60 is supplied by the workpiece supply device. Thereafter, the press machine is driven to lower the upper die 10. Due to this lowering, the upper surface of the die 3 comes into contact with the lower surface of the movable stripper 17 and stops. At this time, the root of the lead 65 is sandwiched between the pressing protrusion 3a of the die 3 and the pressing protrusion 17a of the movable stripper. At the same time, the tip of the lead 65 is sandwiched between the movable die 31 and the movable punch 18.

Further, when the punch holder 5 is pushed down, the movable punch 18 is also pressed down via the roller bearing 20 and pushed down. With this depression, the movable punch 1
8 is the convex cam 2 of the movable stripper 17.
3, the movable punch 18 and the movable die 31 sandwiching the lead 65 are moved downward as shown in FIG. 2 and in a lateral direction perpendicular thereto. The motion obtained by combining these two motions becomes a substantially circular motion centered on the root of the lead 65.

In this state, when the ram is raised to open the lead 65 and the punch holder 5 is raised, the movable punch 18 is raised. When the movable punch 18 is raised, the movable die 31 of the lower die 30 is also moved by the coil spring 4.
4 and the piston 42 is raised. Due to the rise of the piston 42, the movable die 31 also tries to rise while holding the lead 65. However, the bottom dead center sensor S2 detects that the ram is located at the bottom dead center, and outputs the output of the bottom dead center sensor S2 to the programmable controller 5.
Enter 2 After receiving this signal, the programmable controller 52 operates the switching valve 49 to supply compressed air from the joint 48 through the air supply passage 47 to the cylinder hole 41.
Is supplied with compressed air.

By the operation of the piston 42, the coil spring 44 does not push up the movable die 31. If the compressed air is not supplied, the movable die 31
The bent lead 65 is pushed up and deformed. When the upper die 10 is further raised, the leads 65 held by the projections 17a of the movable stripper 17 and the projections 3a of the die 3 are opened. Here, the LSI package 60 as a work is taken out of the lower die 30 by means for removing a workpiece (not shown). Thereafter, the switching valve 49 is switched to stop the supply of the compressed air,
The movable die 31 is pushed up by the force of the coil spring 44 and returned to the original position.

[0023]

First Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of a part of a bending die 1 for lead bending of an LSI package according to a first embodiment of the present invention. FIG. 2 shows a moving locus during lead bending by the bending die 1. The leading end of the lead 65 is gripped by the movable punch 18 and the movable die 31, moved diagonally downward, and the point P moves close to an arc and moves to the point R. At this time, the lead 65 is Z-bent.

The bending die 1 basically includes an upper die 10 and a lower die 3
It consists of 0. At the bottom of the bending die 1 is a die holder 2
The lower end of the die 3 contacts the upper part of the die holder 2 and is integrally fixed by bolts (not shown). A plurality of guide posts 4 are provided on the die holder 2. The upper end of the guide post 4 is movably inserted into a guide post hole 6 provided in the punch holder 5, and guides the punch holder 5 up and down.

[0025]Upper die 10  The shank 7 provided on the upper surface of the punch holder 5,
For attaching to the ram of a press (see Fig. 4)
You. A punch plate 9 is provided on the lower surface 8 of the punch holder 5.
Has been fixed. In the circular hole 11 of the punch plate 9,
Bolt 12 is inserted with play. Bolt 12
The spring insertion hole 13 is
Are formed.

At the upper end of the spring insertion hole 13, a screw 1
4 is screwed. A coil spring 15 is interposed between the screw 14 and the bolt 12. Screw 1
Numeral 4 is for adjusting the strength of the coil spring 15. At the lower end of the bolt 12, the movable stripper 1
7 is screwed in and fixed.

The upper end engaging portion 19 of the movable punch 18 is inserted into the space 16 of the punch plate 9. A roller bearing 20 is arranged between the upper end engaging portion 19 and the punch holder 5. Therefore, the movable punch 18 can move along the lower surface 8 of the punch holder 5, in other words, in a direction perpendicular to the vertical direction of the punch holder 5.

On one side surface of the movable punch 18, concave cams 21 and 21 are formed. On the other side surface of the movable punch 18, convex cams 22, 22 are formed. On the other hand, the movable stripper 17 has the concave cams 21 and
1 are provided, respectively. Further, the convex cam 2 of the movable stripper 17 is provided.
2 and 22 are located at concave positions 24 and 24, respectively.
24 are formed.

[0029]Lower mold 30  On the other hand, the movable strip is placed in the die 3 of the lower mold 30.
A movable die 31 that moves in conjunction with the par 18 is arranged.
ing. One surface of the movable die 31 has a convex cam 3
2, 32 are formed. On the other side of the movable die 31
Are formed with concave cams 33, 33. Meanwhile, die
In the position facing the concave cams 33, 33,
Convex cams 34, 34 are formed. Dice 3
In the position facing the convex cams 32, 32,
The cams 35 are arranged. These cams 32,
33, 34, 35 constitute a cam mechanism, and when actuated,
To create a predetermined contour curve.

The die holder 2 has a cylinder hole 41 formed therein. A piston 42 having two different diameters, a small diameter and a large diameter, is inserted into the cylinder hole 41 so as to be vertically movable. O-rings 43 and 43 ′ are arranged on the outer periphery of the cylinder hole 41. This O-ring 4
Reference numerals 3 and 43 'are for preventing air from leaking between the piston 42 and the cylinder hole 41.

The lower surface of the piston 42 is in contact with the upper end of a coil spring 44. The lower end of the coil spring 44 is in contact with one end of the screw 45. The screw 45 is screwed into the lower end of the cylinder hole 41. Therefore, the strength of the coil spring 44 can be adjusted by turning the screw 45. A roller bearing 46 is interposed between the lower end of the movable die 31 and the upper end of the piston 42. This is to make it possible to easily move the movable die 31 in the lateral direction.

An air supply passage 47 is formed in the die holder 2. One of the air supply paths 47 is the piston 42
The other is connected to a pipe joint 48 communicating with the outside of the die holder 2. The pipe joint 48 is connected to an air source 51 driven by a motor 51 via an electromagnetic valve 50. The opening and closing of the solenoid valve 50 is controlled by a programmable controller 52.

The programmable controller 52 controls the press machine by sequence control. It is a controller that can change the program freely. The programmable controller 52 receives position signals from a top dead center sensor S1 and a bottom dead center sensor S2 provided on a ram or the like of a press machine. The supply and cutoff of air are performed by opening and closing 49 of the solenoid valve 50. The operation panel 53 controls the operation of the press machine 49 and the programmable controller 5.
2 is a key means for input / output for inputting data to 2, and changing a sequence program.

Power is supplied to the programmable controller 52 from an AC power supply 55 via a power supply device 54. The programmable controller 52 operates the press machine 49 with this electric power. By temporarily sending compressed air from the pipe joint 48, the piston 42 pushes down the coil spring 44 to stop the upward movement of the movable die 31. That is, as described later, when the Z bending process of the lead 65 is completed, the movable die 3 is moved by the piston 42.
1 stops moving upward and prevents the Z-bent lead from being deformed.

Operation The operation of the above-described bending die 1 for lead bending of an electric component will be described below. When the solenoid valve 50 is first switched, the supply of air to the piston 42 is cut off (step S in FIG. 6).
₁ , the steps are omitted below. ), The piston 42 is pushed up by the coil spring 44 (S ₂ ). This state is a state where the piston 42 pushes up the movable die 31 from below. The LSI package 60 is supplied onto the die 3 by the workpiece supply device (S ₃ ). Thereafter, the press machine 49 is driven to lower the upper die 10 (S ₄ ). The ram and lowering of the lower mold 10 is detected by the bottom dead center sensor S2 (S _5). Due to this lowering, the upper surface of the die 3 comes into contact with the lower surface of the movable stripper 17 and stops (S ₆ ). At this time, the root portion 64 of the lead 65 is sandwiched between the pressing protrusion 3a of the die 3 and the pressing protrusion 17a of the movable stripper. At the same time, the tip of the lead 65 is sandwiched between the movable die 31 and the movable punch 18 (S
₇ ).

Further, when the punch holder 5 is pushed down, the movable punch 18 is also pressed down via the roller bearing 20 and pushed down. With this depression, the movable punch 1
Eight concave cams 21 and 21 come into contact with the convex cams 23 and 23 of the movable stripper 17. By this contact, the lead 6
As shown in FIG. 2, the movable punch 18 and the movable die 31 sandwiching 5 move downward, that is, in the first direction, and in the transverse direction perpendicular thereto, that is, in the second direction. The motion obtained by combining the two motions is a substantially circular motion centered on the root of the lead 65. The trajectories of these movements can be delicately changed by changing the shape of each cam. The end of the lead 65 is finally bent obliquely downward and is subjected to a so-called Z-bending process. FIG. 3 shows the positions of the movable punch 18 and the movable die 31 with the lead 65 bent.
To show (S _7).

In this state, when the ram is raised to open the lead 65 and the punch holder 5 is raised, the movable punch 18 is raised (S ₉ ). This movable punch 18
Rises, the movable die 31 of the lower die 30 is also pushed up by the coil spring 44, and the piston 42 rises.
As the piston 42 rises, the movable die 31 leads 6
5 tries to ascend while holding it. The bottom dead center sensor S2 detects that the ram is located at the bottom dead center, and outputs the output of the sensor 53 to the programmable controller 52. Immediately after receiving this signal, the programmable controller 52 operates the switching valve 49 to supply compressed air from the joint 48 through the air supply passage 47 to the cylinder hole 41.
To supply compressed air to the (S _8). The length of time of this timer is adjusted to an optimal time (t ₁ or t _{2 in} FIG. 5) while considering factors such as the cycle time of the press and the speed of taking out the workpiece.

By the operation of the piston 42, the coil spring 44 does not push up the movable die 31. If the compressed air is not supplied, the movable die 31
The bent lead 65 is pushed up and deformed. Further, when the upper die 10 is raised (S ₉ ), the lead 65 gripped by the projection 17 a of the movable stripper 17 and the projection 3 a of the die 3 is released (S ₁₁ ).
The movement of the upper mold 10, i.e. the movement of the ram is detected by the top dead center sensor S1 (S _10). Here, the LSI package 60 is readily workpiece is taken out by means of the workpiece removed from the lower mold 30 (not shown) (S _12). After time t (see FIG. 5), stopping the supply of compressed air by switching the electromagnetic switching valve 50 to return the piston 42 to push up the original position of the movable die 31 by the force of the coil spring 44 (S _1).

As a result, the movable punch 18, the movable stripper 17, the movable die 31, and the punch holder 5 return to their original positions and stand by, and all the lead bending processing is completed. As will be understood from the operation of the bending die 1, as described in detail above, since the root portion 64 of the lead 65 is fixed and its tip is moved so as to draw a substantially circular locus, Z bending is realized. No dent marks or scratches are formed on the surface. Since no pulling force is generated during the Z-bending process, no extra stress is generated inside the LSI package. Therefore, the inside of the LSI package is not destroyed. Further, the metal constituting the lead does not adhere to the bending mold 1.

[0040]

FIG. 7 shows a second embodiment. In the first embodiment, the movable punch 18 is attached to the lower surface 8 of the punch holder 5.
Was to move along. In the second embodiment, the movable punch 18a is rolled, that is, rolled. A cylindrical surface 59 is formed on the upper end 19 a of the movable punch 18 a so as to roll on the lower surface 8 of the punch holder 5. Therefore, unlike the first embodiment, no extra parts such as roller bearings are used, so that the apparatus is simple and economical. However, other functions are almost the same as those of the first embodiment.

Therefore, unlike the first embodiment, no extra parts such as roller bearings are used, so that the apparatus is simple and economical. However, other functions are almost the same as those of the first embodiment.

[Other Embodiments] The pistons 42 of the first and second embodiments are driven by air. However, a solenoid driven by an electric current instead of driving the piston 42 may be used.

Further, instead of the piston 42 and the coil spring 44, a spring may be substituted by a pneumatic pressure without using a known spring hydraulic shock absorber or spring. In short, it is preferable to delay the return of the movable dies 31, 31a to their original positions after the Z-bending of the lead.

As described above, the present invention provides
The present invention can be embodied in various other modifications without departing from the essential characteristics of the configuration. for that reason,
The above-described embodiments are merely illustrative in all respects and need not be construed as limiting.

[0045]

As described above, the present invention has the following effects.

A. No plating peeling due to dent marks or scratches on the lead.

B. No soft metal such as tin peeled off adheres to the movable punch, the movable die and the like.

C. It does not act badly as a tensile force during the Z-bending process of the lead, and does not tear off the thin gold wire connecting the IC chip and the lead frame, and does not cause so-called micro cracks in the mold.

D. The life of the bending mold is extended, which is advantageous for depreciation.

E. Since the setup change of the bending mold is reduced, the efficiency of the machine is high, and the productivity is also excellent.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a part of a bending mold according to a first embodiment.

FIG. 2 is a principle view showing the principle of the present invention.

FIG. 3 is a cross-sectional view showing a state where a lead is bent by a bending die.

FIG. 4 is a diagram showing an outline of a system for driving a bending mold.

FIG. 5 is a timing chart of the operation time of the system.

FIG. 6 is a flowchart showing an outline of the operation of the system.

FIG. 7 is a cross-sectional view of a part of a bending mold according to a second embodiment.

FIG. 8 is a cross-sectional view showing a state of lead bending according to the prior art.

FIG. 9 is a cross-sectional view showing a state in which lead bending according to the prior art has been completed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bending die, 2 ... Die holder, 3 ... Die, 5 ... Punch holder, 10 ... Upper die, 18 ... Movable punch, 21, 22
4 ... concave cam, 22, 23 ... convex part, 30 ... lower mold, 31 ...
Movable dies, 33, 35 ... concave cam, 65 ... lead

Claims (3)

(57) [Claims] 1. A bending die (1) for a lead of an electric component comprising an upper die (10) and a lower die (30), having the following requirements: a. The upper die (10) attached to the ram of a press machine
A punch holder (5) forming a part of b. An elastic support member (15) is provided on the punch holder (5).
By the first cam surface (2).
A movable stripper (17) formed with 3,3) for fixing the electrical component; c. The punch holder (5) is provided movably in a direction perpendicular to the vertical movement direction,
And a movable punch having a second cam surface (21, 22) for contacting the first cam surface (23, 24) and creating a locus for bending along with the vertical movement. (18), d. A die holder (2) constituting a part of the lower mold (30); e. A die (3) provided on the die holder (2) for mounting and fixing the electric component and having a third cam surface (34, 35) formed thereon; f. The lead (6) is cooperated with the movable punch (18).
A fourth cam surface (32, 33) for gripping the tip of 5) and forming a trajectory for the bending by contacting the third cam (34, 35) is formed. And a movable die (31) provided in the die (3).
And g. Electrodeposition, characterized in that it comprises a pressing means (44) for the pressing of the movable die (31) for gripping the leading (65) in conjunction with the movable punch (18)
Bending type of lead for electrical parts. 2. A lead mold for an electric component according to claim 1 , further comprising a temporary stopping means (42) for temporarily stopping the operation of said pressing means (44). 3. The piston (4) according to claim 2 , wherein said temporary stop means is operated by a fluid pressure.
2) A bending mold for a lead of an electric component, wherein