JPH07221239A - Lead shaping equipment - Google Patents

Abstract

PURPOSE:To prevent that the lead of a surface mount semiconductor device is bent and tensile stress is applied to it, and enable the L-type bending and shaping, by forming the lower end inner peripheral part of a bending punch in an acute angle, forming the seat part of a bending stand in a specified shape, and bending a lead with the pressing force of the bending punch. CONSTITUTION:The seat part 17 of a bending stand 5 of a lead shaping machine 16 is formed with a slant surface 19 wherein the lead mounting wall 9 side is made lower than the peripheral part, and is so constituted that the bending part of a lead 3 does not come into slide contact with the side wall 10 of the bending stand 5 and the seat part 17. A raised part with which the free end side of the lead 3 comes into slide contact is formed on the outer peripheral side of the seat part 17, and constituted in the manner in which, when the lead 3 is bent, it is bent and shaped so as to apply the end surface part 21 of the lead mounting wall 9 and the raised d part to fulcrums. In a bending punch 7, the lower end inner peripheral part 18 is formed in an acute angle, and comes into line contact with the lead 3 surface, when the lead 3 is pressed down.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount type semiconductor device, for example, a QFP (Quad F), in which a plurality of L-shaped bent leads are led out from a side wall surface of an exterior resin in an aligned state.
lat package) type IC and DIP (DualI)
nline Package) type IC leads, etc.
The present invention relates to a lead shaping machine for bending into a letter shape.

[0002]

2. Description of the Related Art In a surface mount type semiconductor device 1 of this type, as shown in FIGS. 4 and 5, for example, a large number of leads 3 are bent in an L-shape from a side wall surface of an exterior resin 2 in an aligned state. The lead 3 has a structure in which the tip 3a of the lead 3 is bent horizontally and aligned in the same plane.

The surface mount semiconductor device 1 having such a structure is
Although not shown, the tip 3a of the lead 3 bent into an L shape is placed on the printed board and mounted by soldering. Therefore, it is important that the tip portion 3a of the lead 3 in the surface-mounted semiconductor device 1 is shaped in the same direction so as to be horizontally aligned. For example, the tip portion 3a of a certain lead 3 may be protruded, If it is bent, the solder in this part will float or the attachment will not work properly.

For this reason, a lead shaping machine 4 as shown in FIGS. 6 and 7 has been conventionally used for shaping the leads 3 of such a surface-mounted semiconductor device 1. That is, the lead shaping machine 4 is composed of a bending table 5, a lead retainer 6 and a bending punch 7. The surface mounting type semiconductor device 1 is placed on the bending table 5 and the root portion 3b of the lead 3 is leaded. Fix it on the bending table 5 with the presser foot 6, and in this state, bend the punch 7
And push the free end side of the lead 3 onto the bending table 5,
The method of bending the lead 3 is adopted.

More specifically, the bending table 5 has a recess 8 at the center of the surface for accommodating two exterior resin parts of the surface mount semiconductor device 1.
And a lead mounting wall 9 on which the root portion 3b of the lead 3 of the surface mount semiconductor device 1 is mounted on the peripheral surface of the recess 8.
Around the lead mounting wall 9, there is a seat portion 11 that extends horizontally outward from the lower end of a side wall 10 that hangs vertically on the outer periphery of the lead mounting wall 9. That is, the vertically mounted side wall 10 of the lead mounting wall 9 and the seat 11 extending horizontally outward from the lower end of the lead mounting wall 9 are lead-shaped surface-mounted semiconductor devices 1.
Is formed in the same L-shaped cross section as the lead 3 of
A receiving die 12 is formed when the free end side of the lead 3 placed on the lead placing wall 9 is bent and shaped.

Further, the lead retainer 6 is arranged above the lead mounting wall 9 of the bending table 5 so as to be vertically movable, and its lower end surface is pressed against the surface of the lead 3 mounted on the lead mounting wall 9. ,
The root portion 3b of the lead 3 is fixedly supported in a sandwiched manner. Also,
The bending punch 7 is arranged on the outer periphery of the lead retainer 6 so as to be vertically movable on the seat portion 11 along the side wall 10 surface of the lead mounting wall 9 of the bending table 5, and at the lower end inner peripheral portion 13 of the lead punch 7. The free end side of 3 is pushed down onto the seat 11.

The lead shaping machine 4 having the above-mentioned structure bends the exterior resin 2 portion of the surface-mounted semiconductor device 1 to be lead-shaped into a bending table 5
The lead 3 is mounted on the lead mounting wall 9, the lead retainer 6 is lowered, the lead 3 is fixed on the lead mounting wall 9, and then the bending punch 7 is lowered. While pushing the lead 3 at the lower end inner peripheral portion 13, the lead 3 is pushed down along the surface of the side wall 10 of the lead mounting wall 9.
Then, the lead 3 has its root 3b bent at the upper end of the side wall 10 of the lead mounting wall 9, and then the free end thereof is pressed against the seat 11, and the tip 3 of the lead 3 is also pressed.
a is bent at the lower end of the side wall 10. Therefore, lead 3
Is bent according to the shape of the receiving die 12 formed in the L shape by the side wall 10 and the seat portion 11 of the bending table 5, and the tip 3a of the lead 3 is bent in the horizontal L shape. It is.

However, the side wall 10 of the lead mounting wall 9 of the bending table 5 is formed vertically in this way, and the bending punch 7 is formed.
The lead 3 is hung along the side wall 10 of the lead mounting wall 9, and the lead 3 is slidably contacted between the side wall 10 of the lead mounting wall 9 and the inner wall 14 of the punch 7 to bend and shape the lead. At this time, the side wall 10 of the lead mounting wall 9 and the inner wall 1 of the punch 7
There was a problem that the surface of the lead 3 was rubbed between 4 and a downward pulling force acted on the lead 3 to tear the lead.

Therefore, as shown in FIGS. 8 and 9,
The side wall 10 of the lead mounting wall 9 of the bending table 5 is enlarged downward and inclined, the inner wall 14 surface of the bending punch 7 is similarly inclined, and the lower end inner peripheral portion 13 thereof is attached to the lead supporting wall 9 of the bending table 5. There is also proposed a lead shaping machine 15 which is designed to be separated from the surface of the side wall 10.

Like the lead shaping machine 4, the lead shaping machine 15 is also a surface-mounted semiconductor device 1 for lead shaping.
2 parts of the exterior resin of the
After fixing and supporting the root portion 3b of the lead 3 on the lead mounting wall 9 by the lead retainer 6, the bending punch 7 is lowered and the lower end inner peripheral portion 13 of the bending punch 7 presses the upper surface of the lead 3 on the free end side. The lead mounting wall 9 is pushed down along the side wall 10 surface.

In this case, since the bending punch 7 has its lower end inner peripheral portion 13 separated from the side wall 10 of the lead mounting wall 9 of the bending table 5, the side wall of the lead mounting wall 9 is depressed when the lead 3 is pushed down. The rubbing of the lead 3 between the surface 10 and the surface of the inner wall 14 of the bending punch 7 is eliminated, and the downward pulling force on the lead 3 is further alleviated.

Then, when the bending punch 7 is further lowered, the free end portion of the lead 3 is pressed against the seat portion 11, and finally, as shown in FIG. The portion 3a is bent at the lower end portion of the side wall 10, and like the lead shaping machine 4, the free end portion of the lead 3 has the side wall 10 and the seat portion 1.
The lead 3 is bent in conformity with the shape of the substantially L-shaped receiving die 12 and the tip 3a of the lead 3 is bent in a substantially L-shape which is horizontal.

[0013]

However, the side wall 10 of the bending table 5 and the inner wall 14 of the bending punch 7 are inclined in this manner, and the lower end inner peripheral portion 13 of the bending punch 7 is attached to the side wall of the lead mounting wall 9. The lead shaping machine 15 spaced apart from the bending punch 7 separates the bending punch 7 from the point A at which the lower end inner peripheral portion 13 contacts the lead 3 as shown by the arrow in FIG. When the lead 3 is shaped by pushing down to the point D, which is the point, the lower end inner peripheral portion 13 of the bending punch 7 goes from the point A to the point C in the vicinity of the lowermost point D through the point B in the intermediate portion. Until reaching, the lower end inner peripheral portion 13 of the bending punch 7 is sufficiently separated from the side wall 10 of the lead mounting wall 9,
It does not rub and can be pushed down by sliding on the lead 3. However, from point C near the bottom position to D at bottom dead center
Up to the point, the space between the side wall 10 of the lead mounting wall 9 and the inner wall 14 of the bending punch 7 is narrowed, and the lead 3 is rubbed in a sandwiched manner,
Further, although a downward pulling force acts on the lead 3 and is relaxed as compared with the lead shaping machine 4, it is not a complete solution.

Further, in each of the conventional lead shaping machines 4 and 15, the lead 3 fixed on the lead mounting wall 9 is used.
The lower end inner circumferential portion 13 of the bending punch 7 is pressed against the free end side of the bending punch 7, and the bottom surface of the bending punch 7 is struck on the L-shaped receiving die 12 formed on the side wall 10 side of the lead mounting wall 9 to lead. Three
Therefore, the lead 3 is not plated on the lower end of the side wall 10 of the bending table 5 or on the seat portion 11 during the shaping process. There is a fatal problem that this is gradually accumulated during the shaping process of the leads 3 and transferred to the leads 3 of the surface-mounted semiconductor device 1 to be shaped, resulting in a product defect.

Therefore, the present invention has been made in view of the above problems and the like, and provides a lead shaping machine in which lead rubbing and lead pulling force are not generated during shaping operation, and lead plating is not transferred. Is intended.

[0016]

Therefore, in the lead shaping apparatus according to the present invention, the lead root portion is fixed to the upper surface of the lead mounting wall, and the inside of the lower end of the bending punch disposed above the outer periphery of the lead mounting wall. The peripheral part is brought into contact with the free end side of the lead and lowered along the side wall of the lead mounting wall, and the tip part of the lead is pushed onto the seat part extending and arranged at the lower end peripheral edge of the lead mounting wall. In a lead shaping machine of a surface mounting type semiconductor device, wherein a lead root portion and a lead tip portion are bent into an L shape, the bending punch has an acute lower end inner peripheral portion and the seat In the lead shaping device according to the present invention, the seat portion is provided with a mountain-shaped portion on the peripheral portion, and the mountain portion is formed on the peripheral portion. Tip of the lead abutted on the curved part by the bending punch It is characterized in that the parts are in sliding contact with each other.

[0017]

Since the inner peripheral portion of the lower end of the bending punch is formed at an acute angle, it is possible to push down the lead without being twisted while coming into line contact with the lead surface when descending. Further, since the seat portion with which the lead tip abuts is formed on the inclined surface with the lead mounting wall side lower than the peripheral edge portion, when the lead tip portion is bent, the lead bending point is different from the side wall or the seat portion of the lead mounting wall. No sliding contact, no twisting or pulling force on the lead. In addition, since a mountain-shaped portion is provided on the peripheral side of the seat portion so that the tip of the lead is in sliding contact, when the bending punch descends, the tip of the lead slides on the seat without slipping and twists the lead. Can be folded without Also,
Unlike the conventional lead shaping machine, the bending punch does not press and shape the lead by following the bending punch to the bending die, and when bending the lead tip, the lead bending point slides against the side wall or seat of the lead mounting wall. Since the lead tips are bent and shaped without making contact with each other, plating does not adhere to the side wall of the lead mounting wall or the seat portion, and plating transfer defects are eliminated.

[0018]

Embodiments of the present invention will be described in detail below with reference to the drawings.

1 and 2 are side sectional views of a lead shaping machine 16 according to the present invention. Like the conventional lead shaping machines 4 and 15, the lead shaping machine 16 is also composed of a bending table 5, a lead retainer 6 and a bending punch 7. The bending table 5 has a concave portion 8 for accommodating the exterior resin 2 of the surface-mounted semiconductor device 1 to be shaped, and a lead for supporting the root portion 3b of the lead 3 of the surface-mounted semiconductor device 1 on the peripheral surface of the concave portion 8. The mounting wall 9 and a seat portion 17 that extends from the lower end of the side wall 10 of the lead mounting wall 9 to the peripheral edge at the periphery of the lead mounting wall 9 and restricts the movement of the lead 3 on the free end side during lead shaping. And have. The lead retainer 6 is vertically movable above the lead mounting wall 9 of the bending table 5, and its lower end surface is pressed against the surface of the lead 3 mounted on the lead mounting wall 9 to move the lead 3 The root portion 3b is fixedly supported in a sandwiched manner. Further, the bending punch 7 is arranged on the outer periphery of the lead retainer 6 so as to be vertically movable on the seat portion 17 along the side wall 10 of the lead mounting wall 9 of the bending table 5, and at the lower end inner peripheral portion 18 of the lead punch 7. The free end side of 3 is pushed down onto the seat portion 17.

This lead shaping machine 16 is different from the lead shaping machines 4 and 15 in that the shape of the seat portion 17 for restricting the movement of the lead 3 of the bending table 5 on the free end side and the lead 3 of the bending punch 7 are different. It is only the shape of the lower end inner peripheral portion 18 that pushes down. Therefore, the same functional parts as those of the lead shaping machines 4 and 15 are designated by the same reference numerals, and the description thereof will be omitted.

That is, the seat portion 17 of the bending table 5 of the lead shaping machine 16 is formed by an inclined surface 19 whose inner side, that is, the lead mounting wall 9 side is lower than the peripheral edge portion, and as described later, bends the lead. Sometimes, the bent portion of the lead 3 does not come into sliding contact with the side wall 10 or the seat portion 17 of the bending table 5. In addition, a mountain-shaped portion 20 is formed on the outer peripheral side of the seat portion 17 to which the free end side of the lead 3 is slidably contacted, and when the lead is bent, the lead 3 and the mountain-shaped portion 20 of the end face 21 of the lead mounting wall 9 are formed. It is configured to be bent and shaped with the two points as fulcrums. The bending punch 7 is configured such that the lower end inner peripheral portion 18 for pushing down the lead 3 is formed at an acute angle, and when the lead 3 is pushed down, a line contact is made on the surface of the lead 3.

In the lead shaping machine 16 having such a structure, as in the conventional lead shaping machines 4 and 15, the exterior resin 2 part of the surface-mounted semiconductor device 1 to be lead shaped is mounted in the recess 8 of the bending table 5. After the root portion 3b of the lead 3 placed on the lead mounting wall 9 is fixedly supported by the lead retainer 6, the bending punch 7 is lowered to form the lower end inner peripheral portion of the bending punch 7 as shown in FIG. 18 is pressed against the upper surface of the lead 3 on the free end side, and is pushed down along the side wall 10 of the lead mounting wall 9. in this case,
Since the bending punch 7 is configured to be separated from the surface of the side wall 10 of the lead mounting wall 9 by the thickness of the lead 3 or more, and the upper surface of the lead 3 is pushed down in line contact, the surface of the lead 3 is not rubbed or pulled.

Then, as shown in FIG. 3B, when the bending punch 7 is further lowered, the tip 3a of the lead 3 is
Comes into contact with the mountain-shaped portion 20 on the outer periphery of the seat portion 17. Therefore, the lead 3 has two fulcrums, the end face portion 21 (point a) of the lead mounting wall 9 and the mountain portion 20 (point b) of the seat portion 17, and the space between them (point c) is within the lower end of the bending punch 7. The peripheral portion 18 comes into line contact and is bent and shaped. At the time of this bending and shaping, since the lower end inner peripheral portion 18 of the bending punch 7 is formed at an acute angle, the bending punch 7 makes a line contact on the surface of the lead 3, and the seat portion 17 is formed on the outer periphery of the mountain-shaped portion 2.
Since 0 is formed and the free end side of the lead 3 moves on the mountain portion 20 without slipping, the lead 3 smoothly descends without rubbing or pulling force.

Next, as shown in FIG. 3 (c), when the bending punch 7 descends to the bottom dead center, the tip 3a of the lead 3 is bent and shaped into an L shape. At this final stage, the bent portion 22 of the bent lead tip portion 3a is formed by the inclined surface 19 in which the seat portion 17 is lower than the peripheral portion on the side wall 10 side. Since there is a gap d between them, rubbing and tensile force do not act on the surface of the lead 3. The bending of the tip portion 3a of the lead 3 causes the bending punch 7 to descend to the vicinity of the bottom dead center, and the lower end inner peripheral portion 18 formed at an acute angle of the bending punch 7 causes the portion near the tip portion 3a of the lead 3 to lead. 3 is pressed and deformed against the inclined surface 19 of the seat portion 17, the distance from the side wall 10 of the bending punch 7, the angle of the inclined surface 19 of the seat portion 17, and the mountain-shaped portion 20 of the seat portion 17. R and other appropriate conditions are set.

[0025]

As described above, according to the present invention, when the leads of the surface mount type semiconductor device in which a large number of leads are led out from the side wall surface of the exterior resin in an aligned state are bent into an L-shape, the conventional method is used. Instead of pressing and shaping the lead following the bending mold, the seat part of the bending table is formed into a predetermined shape, and the lead is bent by the pressing force of the bending punch to form a bend. Rubbing of the lead surface and pulling force do not act, eliminating lead breakage. Further, since the lead shaping is not made to follow the bending die, there is no plating transfer defect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a lead shaping machine of the present invention before lead shaping.

FIG. 2 is a cross-sectional view after lead shaping by the lead shaping machine of FIG.

FIG. 3 is a partial cross-sectional view showing the state of each stage during lead shaping by the lead shaping machine of FIG.

FIG. 4 is a front view showing an example of a surface mount semiconductor device.

FIG. 5 is a side view of FIG.

FIG. 6 is a cross-sectional view of a conventional lead shaping machine before lead shaping.

7 is a cross-sectional view after lead shaping by the lead shaping machine of FIG.

FIG. 8 is a cross-sectional view of a conventional lead shaping machine before lead shaping.

9 is a cross-sectional view after lead shaping by the lead shaping machine of FIG.

FIG. 10 is a cross-sectional view showing the state of each stage during lead shaping by the lead shaping machine of FIG.

[Explanation of symbols]

 1 Surface mount type semiconductor device 2 Exterior resin 3 Lead 3a Tip part 3b Root part 5 Bending table 6 Lead retainer 7 Bending punch 8 Recess 9 Lead mounting wall 10 Side wall 16 Lead shaping machine 17 Seat part 18 Lower end inner circumference part 19 Inclined surface 20 Crest 21 End face 22 Bend

Claims (2)

[Claims] 1. A lead root portion is fixed to an upper surface of a lead mounting wall, and a lower end inner peripheral portion of a bending punch disposed above an outer periphery of the lead mounting wall is brought into contact with a free end side of the lead. It is lowered along the side wall of the mounting wall, and the tip end portion of the lead is pressed against the seat portion extendingly arranged at the lower end peripheral edge of the lead mounting wall to form the lead root portion and the lead tip end portion into an L shape. In a lead shaping machine of a surface-mounting type semiconductor device adapted to be bent, the bending punch is formed such that an inner peripheral portion of a lower end thereof is formed into an acute angle, and the seat portion is an inclined surface having a lead mounting wall side lower than a peripheral portion. A lead shaping device, which is characterized in that: 2. The seat portion is provided with a mountain-shaped portion at a peripheral edge thereof, and the tip end portion of the lead abutted by the bending punch slides on the mountain-shaped portion. Item 1. The lead shaping device according to item 1.