JP3384672B2 - Lead molding equipment for semiconductor devices - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention, a semiconductor device Li
The present invention relates to a cord molding device .

[0002]

2. Description of the Related Art A conventional lead frame molding apparatus of this type will be described with reference to FIGS. 14 is a plan view showing the lead frame, FIG. 15 is a side view of the molding apparatus before the lead frame molding process, FIG. 16 is an enlarged side view of a main part during the molding process, and FIG. 17 is an expansion of a main part in a completed molding process. It is a side view. In the figure, 1 is a lead frame, 1a is a positioning hole for positioning when processing the lead frame 1,
1b is a die pad 1 which is a base for bonding chips
It is a suspension lead for holding c to the lead frame 1. Reference numeral 2 is a lower die set, 3 is a guide rail for guiding and conveying the lead frame 1 into the die, 4 is a die plate held by the lower die set 2, and 5 is a lead plate held by the die plate 4. A die for molding the die pad 1c of the frame 1, 6 is a guide post fixed to the lower die set 2, 7 is an upper die set which moves up and down with the guide post 6 as a guide, and 8 and 9 are an upper die set 7. Fixed backing plate and punch plate, 10 is a guide post fixed to the punch plate 9, 11 is a stripper plate that moves up and down with the guide post 10 as a guide, 12 is a coil spring incorporated in the upper die set 7, 13 is a screw for assembling the coil spring 12 into the upper die set 7, and 14 is a reaction force applied by the coil spring 12. Push rod, stripper piece fixed to the stripper plate 11 15,
Reference numeral 16 is a pilot pin fixed to the stripper piece 15, 17 is a push pin held by the punch plate 9 and guided by the stripper piece 15, 18 is a punch also held by the punch plate 9, and FIG. The amount of crushing the lead frame 1 by 17.

Next, the operation will be described. The lead frame 1 is conveyed onto the die 5 held and fixed to the die plate 4 in a state where the lead frame 1 enters the groove portion 3a of the guide rail 3 guided by the lower die set 2. Then, the upper die set 7 descends using the guide post 6 as a guide,
Along with this, the stripper piece 15 held by the stripper plate 11 descends, and the pilot pin 1
6 enters the positioning hole 1a of the lead frame 1 to position the lead frame 1, and the guide rail 3 is pushed down to clamp the lead frame 1 with the die 5. Thereafter, as the upper die set 7 is further lowered, the stripper piece 15 pushes up the push rod 14 through the stripper plate 11 to bend the coil spring 12 to further pinch the lead frame 1, and to continue lowering. The punch 18 attached to the backing plate 8 and the punch plate 9 sinks the die pad 1c downward while forming the suspension lead 1b of the lead frame 1 (FIG. 16). Then, at a position just before the bottom dead center of the upper die, that is, before the bottom dead center by the crush amount a of the lead frame by the push pin 17, the push pin 1
7 comes into contact with the lead frame, and the upper die is lowered by the crushing amount a (FIG. 17) to supply the extension amount required for molding the lead frame 1. After processing, the upper die is raised and the lead frame 1 is moved to the groove portion 3 of the guide rail 3.
It is guided by a and conveyed, and one molding process is completed.

[0004]

Since the conventional lead frame molding apparatus for a semiconductor device is configured as described above, the crushing amount of the lead frame can be supplied only before the completion of the molding of the die pad portion. It has been impossible to supply the amount of extension of the lead frame that sometimes occurs. Therefore, when the lead frame is crushed by the push pin, internal stress has already been generated in the lead frame, which causes warping of the lead frame and deformation of the die pad after molding, resulting in chip cracking due to defective die bonding and wire bonding. There was a problem such as a defect.

The present invention has been made to solve the above problems, and supplies the amount of extension of the lead frame required during molding during molding of the die pad portion at an arbitrary timing within the molding stroke. Configured to allow
And aims to thereby less warpage of the lead frame and the die pad portion to obtain a lead frame forming apparatus with high accuracy.

[0006]

According to a first aspect of the present invention, there is provided a lead forming apparatus which moves up and down together with an upper die set.
The stripper piece and punch, and the above punch are relative
Separate operation is possible and lead frame squeezing pressure is possible
It has an adjusted push pin.

In the lead forming apparatus according to the second aspect of the present invention, a protrusion is provided on the lead frame contact surface of the stripper piece.

According to a third aspect of the present invention, in the lead forming apparatus, a protrusion is provided on the lead frame contact surface of the stripper piece, and a recess is provided on the lead frame contact surface of the die facing the lead frame contact surface.

In a lead forming apparatus according to a fourth aspect of the present invention, the punches are divided into three, and the punches on both sides are set longer than the central punch.

In the lead forming apparatus according to the fifth aspect of the present invention, the push pin is provided with a heel portion.

In the lead forming apparatus according to the sixth aspect of the present invention, the die is movable.

In a lead forming apparatus according to a seventh aspect of the present invention, the punch is divided into three parts and both sides are set to be longer than the central part, and the movable die facing the punch is provided with a recess. is there.

In the lead forming apparatus according to the eighth aspect of the present invention, a cylinder is provided so as to restrict the rise of the movable die.

In the lead forming apparatus according to the ninth aspect of the present invention, the push pin is operated by the actuator whose operation is controlled by the control box.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. An embodiment of the present invention will be described below with reference to the drawings. Figure 1
Is a side view showing the lead frame molding apparatus according to Embodiment 1 of the present invention, FIG. 2 is an enlarged side view of an essential part of the forming apparatus before processing, FIG. 3 is an enlarged side view of an essential part during processing, and FIG. It is a principal part expanded side view at the time. In the figure, 1 is a lead frame, 2 is a lower die set, 3 is a guide rail for guiding and transporting the lead frame 1 into a mold, 4 is a die plate positioned and held by the lower die set 2, and 5 Is positioned and held by the die plate 4, and the lead frame 1
Die for forming the die pad 1c, 6 is a guide post which is positioned and fixed to the lower die set 2, 7 is an upper die set which moves up and down with the guide post 6 as a guide, 8 and 9
Is a backing plate and punch plate that are positioned and fixed to the upper die set 7, 10 is a guide post that is fixed to the punch plate 9, 11 is a stripper plate that moves up and down with the guide post 10 as a guide, and 12 is the upper die set 7 A coil spring incorporated therein, 13 is a screw for incorporating the coil spring 12 into the upper die set 7, 14 is a push rod applied with a reaction force by the coil spring 12, and 15 is positioned and held by the stripper plate 11. The stripper piece 16 is a pilot pin. Next, 19 is a punch held in the center of the punch plate 9, and 20 are push pins which are arranged on both sides of the punch 19 and whose vertical movement is movable relative to the punch 19 so as to be separately operable. Reference numeral 21 is a push-down pin for pushing down the push pin 20, 22 is a coil spring for generating a reaction force on the push-down pin 21, and 23 is a screw for incorporating the coil spring 22 into the upper die set 7.

Next, the operation will be described. The lead frame 1 enters the groove portion 3a of the guide rail 3 guided by the lower die set 2, and is conveyed onto the die 5 held and fixed on the die plate 4 positioned by the lower die set 2. Then, the upper die set 7 positioned by the guide posts 6 attached to the lower die set 2 descends, and along with this, the stripper plate 11 attached to the upper die set 7 and the holding and fixing to the stripper plate 11 are carried out. The stripper piece 15 is also lowered, and its pilot pin 16 is positioned in the positioning hole 1a formed in the lead frame 1.
At the same time, the lead frame 1 is pinched with the die 5. Thereafter, the upper die set 7 is further lowered, and the stripper piece 15 pushes up the push rod 14 via the stripper plate 11 to bend the coil spring 12 and further pinch the lead frame 1. Next, as shown in FIG. 2, the push pin 20 contacts the lead frame 1 prior to the punch 19, and the upper end surface of the push pin 20 contacts the push-down pin 21. Further, the upper die descends, and as shown in FIG. 3, when the lead frame 1 is started to be crushed by the push pin 20, the punch 19 starts forming the suspension lead portion 1b of the lead frame 1 at the same time. When the push pin 20 crushes the lead frame 1 by a certain amount, the load required for crushing becomes larger than the pressing force, and the push pin 20 lifts the pressing pin 21 to bend the coil spring 22 and relatively. The push pin 20 is stopped with respect to the lead frame 1. Next, as shown in FIG. 4, the lead frame 1 is crushed by the push pins 20 and then the upper die set 7 is pressed.
Is lowered to the bottom dead center and the punch 19 is further lowered to complete the forming process. After processing, the upper die moves up, the lead frame 1 is guided by the groove portion 3a of the guide rail 3 and conveyed, and one step is completed. In addition, in the above device, the push pin 20 is adjusted by adjusting the screw allowance of the screw 23 or by replacing the coil spring 22.
The crushing pressure on the lead frame 1 can be easily adjusted.

Embodiment 2. In addition, in the above-described embodiment, the portion of the stripper piece 15 that clamps the lead frame 1 is a flat surface. However, as shown in FIG. 5, by providing the convex portion 24 on the lower surface thereof, it is crushed by the push pin 20 and generated. The extension is prevented from occurring on the side of the frame frame facing the die pad 1c portion of the lead frame 1, and the lead frame 1 is securely clamped when it is processed, so that the processing position does not shift. According to this embodiment, the lead frame 1
Since it is possible to mitigate the influence of the crushing amount by the push pin 20 on the frame frame side facing the die pad 1c portion, it is possible to suppress the deformation of the lead frame 1.

Embodiment 3. In the second embodiment, the lead frame 1 of the die 5 is
Although the place where the pressure is clamped is a flat surface, as shown in FIG. 6, a concave portion 25 is provided in a portion of the upper surface facing the convex portion 24, and the concave portion 25 is used in combination with the convex portion 24 according to the second embodiment. Further, it is possible to further prevent the crushed extension of the lead frame 1 from occurring on the side of the frame frame facing the die pad 1c portion of the lead frame 1, and to reliably clamp the lead frame 1 when processing it so that the processing position shifts. Will not occur.

Embodiment 4. FIG. 7 shows another embodiment of the punch.
6 is divided into three into 26a, 26b, and 26c, and the punches 26a and 26c on both sides are separated from the punch 26 in the central portion.
It is formed to project downward a little longer than b. The suspension lead 1b for forming is formed by the punches 26a and 26c on both sides so that the forming load is concentrated on the suspension lead 1b during forming, and the forming force and the punch scratches are given as much as possible. No die pat 1
The part c is formed by the central punch 26b. According to this embodiment, since the molding of the suspension lead 1b and the sinking punch of the die pad 1c are separated from each other, adjustment at the time of molding is easy, and the die pad 1
The scratches and dents that the punch 26b exerts on the c portion are reduced,
High quality products can be obtained.

Embodiment 5. Further, in the above embodiment, the tip of the push pin 20 is a flat surface, but as shown in FIG. 8, by providing the heel 27 portion protruding by a crushing amount of the lead frame 1 and a considerable amount, the lead frame 1 is always fixed. By making the amount of crushing constant, the supply of elongation is stabilized and a high quality product is obtained.

Sixth Embodiment Further, in the above-mentioned embodiment, the die 5 is fixed.
As shown in FIG. 3, the movable die 28 is divided into movable portions for holding the die pad 1c portion, and the die pad 1c portion of the lead frame 1 is formed while being pressed by the movable die 28 and the punch 19. Thus, the warp of the die pad 1c portion can be reduced. In the figure, 28a is a push pin of the movable die 28, and 29 and 30 are coil springs and screws incorporated in the lower die set 2.

Embodiment 7. Further, in FIG. 9 of the sixth embodiment, the die pad 1 of the lead frame 1 is formed by the movable die 28 having a flat upper surface and the punch 19.
Although it is shown that the c part is clamped and molded, the die pad 1c
In a semiconductor device in which scratches on the surface of
As shown in FIG. 10, the movable die 28 is provided with, for example, a concave portion 28 b corresponding to the plate thickness of the lead frame 1,
By providing a constant clearance between the die pad 1c portion and the die pad 1c portion, the die pad 1c portion is prevented from hitting the movable die 28, and the punch 26 divided into three as shown in FIG. , Effective for both upper and lower warpage. According to this embodiment, since the suspension leads 1b of the lead frame 1 are received by the convex portions 28c on both sides, even if the die pad 1c has a slight warp, the die pad 1c does not hit the die 28 and the punch 26b.
Further, when the die pad portion has a prescribed warp amount or more, the warp can be suppressed by coming into contact with the punch 19 or the die 28, so that the warp can be corrected. Therefore, there is an effect of minimizing the scratches on the surface of the die pad 1c.

Embodiment 8. Further, in the movable die 28 shown in FIG. 9 of the sixth embodiment, as shown in FIG. 11, a cylinder 31 for controlling the rising timing of the movable die 28 is attached, and the cylinder 31 advances at the bottom dead center of the upper die. Then, the movable die 28 is held, and then, when the upper die is raised and the lead frame 1 guided by the guide rail 3 is raised, the cylinder 31 is retracted and the movable die 28 is raised.
According to this embodiment, since the die pad 1c portion does not receive the stress that the movable die 28 tries to rise when the punch 19 rises, the moldability of the die pad 1c of the frame 1 is further improved.

Ninth Embodiment In FIG. 1, the reaction force is applied to the push pin 20 by the coil spring 22. However, as shown in FIG. 12, an oil damper 32 is used to keep the relationship between the movement amount of the push pin 20 and the reaction force constant. Good. According to this embodiment, when the suspension lead 1b portion of the lead frame 1 is crushed, the suspension lead 1b portion can be crushed with a constant load from the crushing start to the completion, and the extension amount of the suspension lead 1b portion of the lead frame 1 can be stabilized. Can be supplied.

Embodiment 10. Furthermore, as shown in FIG. 13, an actuator 33 is attached in place of the coil spring 22 that gives a reaction force to the push pin 20, and a control box 34 that interlocks with the operation of the punch 19 is incorporated.
The bending state of the lead frame 1 may be managed by recognizing the bending state by the control box 34 and optimally controlling the operation of the push pin 20. According to this embodiment, the molding state of the lead frame 1 and the extending state of the suspension lead 1b can be optimized by controlling the stroke of the push pin, so that a high quality die pad sink can be realized.

Eleventh Embodiment Further, in the above-described embodiment, the case of the device for molding the die pad 1c portion of the lead frame 1 has been described, but it may be an inner lead portion or another place, and the same effect as that of the above-described embodiment is obtained.

[0027]

The semiconductor device according to claim 1 of the present invention
According to the lead forming device, the push pin can be moved separately from the punch.
As well as crushing pressure with a push pin
Since the structure is adjustable, the lead frame is molded.
The lead frame with a push pin before
With, it is possible to supply the proper amount of elongation required for molding.
The lead frame deformation is reduced, and the flatness is outstanding.
The excellent effect of improving quality and obtaining highly accurate products
There is. In addition, the internal stress of the lead frame molding is low.
The heat cycle property is improved and the reliability is high.
Bonding is also possible, and the effect of obtaining high quality is also
It

A semiconductor device according to claim 2 of the present invention
According to the card forming device,
The extension that faces the die pad section of the lead frame.
Prevents generation on the ram frame side and clamps during processing
Is reliable and deformation of the lead frame is suppressed.

The semiconductor device according to claim 3 of the present invention is
According to the card forming apparatus, in addition to the configuration described in claim 2,
By using it, the crushed extension of the lead frame
Frame frame side facing the die pad part of the lead frame
It is further prevented from happening to the
Will be more reliable.

The semiconductor device according to claim 4 of the present invention is
According to the card molding device, adjustment during molding is easy and
Also, scratches and dents caused by punching on the die pad are reduced.
And a high quality product is obtained.

The semiconductor device according to claim 5 of the present invention is
According to the card forming device, the crush amount of the lead frame can be reduced.
Stable supply, stable supply and high quality products
To be

A semiconductor device according to claim 6 of the present invention
According to the card forming device, the warp of the die pad part is reduced.
be able to.

A semiconductor device according to claim 7 of the present invention is
According to the card forming device, the die pad part hits the movable die.
And the punch is shown in claim 4.
By using together with the punch of the structure
It has a suppressing effect on the surface of the die pad and can be corrected.
Scratches can be minimized.

The semiconductor device according to claim 8 of the present invention is
According to the card forming device, when the punch rises, the movable die
The die pad does not receive the stress that a
Thus, the moldability of the frame die pad is improved.

A semiconductor device according to claim 9 of the present invention
With the card forming device, the stroke of the push pin is suppressed.
Control the lead frame molding state and suspension leads.
Since the extended state of the section can be optimized, high quality
It is possible to submerge the die pad.

[Brief description of drawings]

FIG. 1 is a side view showing a lead frame molding apparatus according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged side view of the lead frame molding apparatus in FIG. 1 before processing a lead frame.

FIG. 3 is a partially enlarged side view of the lead frame molding apparatus in FIG. 1 during processing of a lead frame.

4 is a partially enlarged side view of the lead frame molding apparatus of FIG. 1 at the end of lead frame processing.

FIG. 5 is a side view of a stripper piece showing a second embodiment of the present invention.

FIG. 6 is a side view of a die showing a third embodiment of the present invention.

FIG. 7 is a side view of a punch showing a fourth embodiment of the present invention.

FIG. 8 is a perspective view of a push pin showing a fifth embodiment of the present invention.

FIG. 9 is a side view of a lower mold showing Embodiment 6 of the present invention.

FIG. 10 is a side view of a movable die and a punch showing a seventh embodiment of the present invention.

FIG. 11 is a side view of a lower mold showing the eighth embodiment of the present invention.

FIG. 12 is a side view of an upper mold showing Embodiment 9 of the present invention.

FIG. 13 is a conceptual diagram of actuator control showing a tenth embodiment of the present invention.

FIG. 14 is a plan view showing a lead frame.

FIG. 15 is a side view of a conventional lead frame molding apparatus before lead frame molding.

FIG. 16 is a partially enlarged side view of the conventional lead frame molding apparatus during lead frame molding.

FIG. 17 is a partially enlarged side view of a lead frame molding apparatus in a conventional lead frame molding completed state.

[Explanation of symbols]

1 lead frame, 1a positioning hole, 1b suspension lead, 1c die pad, 2 lower die set, 3 guide rail, 3a groove, 4 die plate, 5 die, 6
Guide post, 7 upper die set, 8 backing plate, 9 punch plate, 10 guide post, 1
1 stripper plate, 12 springs, 13 screws, 14 push rods, 15 stripper pieces,
19 punches, 20 push pins, 21 push down pins,
22 coil spring, 23 screw, 24 convex portion, 2
5 recesses, 26, 26a, 26b, 26c punches, 2
7 heel, 28 movable die, 28b recess, 31 cylinder, 32 oil damper, 33 actuator, 34 control box.

Claims (9)

(57) [Claims] 1. A punch and a push pin are driven from above a lead frame fixed on the die for supplying and positioning,
Molding device for punching leadframe bending and pushpin crushing leadframe
In the above, the upper die set is supported by the upper die set.
Stripper piece and punch that move up and down together with
Supported by the upper die set and relatively to the punch
Separate operation is possible and the crushing pressure of the lead frame can be adjusted.
Semiconductor device characterized by having a push pin
Lead forming equipment. The lead frame contact surface of 2. A stripper piece, according to claim 1, characterized in that a prevention protrusion to crush by extending the amount of the framework side of the displacement prevention and suspension leads of the lead frame A semiconductor device lead forming apparatus. 3. A recess for preventing displacement of the lead frame and for preventing an amount of extension due to crushing of the suspension lead portion from occurring on the frame frame side on the lead frame contact surface of the die on the surface facing the convex portion of the stripper piece. Characterized by
The lead forming apparatus for a semiconductor device according to claim 2 . 4. The lead forming apparatus for a semiconductor device according to claim 1 , wherein the punch for forming the lead frame is divided into three, and the punches on both sides are set longer than the center punch. 5. The lead forming apparatus for a semiconductor device according to claim 1 , wherein the push pin is provided with a heel portion. 6. The lead forming apparatus for a semiconductor device according to claim 1 , wherein the die is movable, and the lead frame can be formed while pressing the die pad portion with the punch and the die. 7. The lead forming apparatus for a semiconductor device according to claim 4 , wherein the die is movable, and a recess is provided on the upper surface of the movable die. 8. The lead forming apparatus for a semiconductor device according to claim 6, further comprising a cylinder for restricting an upward movement of the movable die at a position where the movable die is lowered. 9. recognizes a state bent by the punch and control BOX for controlling comprises an actuator which is controlled the operation by this control BOX, claims, characterized in that it has a pushpin operated by the actuator
1. A semiconductor device lead forming apparatus according to 1.