JP2002184789A - Lead frame transfer apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform positional correction between a pair of lead frames for transfer. SOLUTION: A pair of lead frames 2 are supported as bridged between a pair of locking pawls 61a and 61b so that one edges of the supported lead frames 2 is held by the locking outer pawl 61b. A control computer calculates a difference E (= LkTk to LKTK) between a space Lp of initial stage and a space Lk of transport stage, that is, when a preset state (Lp=Lk) is changed; controllably drives a servo motor 641 in such a direction that the difference E becomes zero, and corrects the position of the pawl 61b having the frames 2 held thereon. Accordingly, a positional deviation between the pair of frames 2 and 2 before and after the transfer can be easily corrected and the frames can be transferred smoothly and suitably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame transfer device suitable for receiving and transferring a lead frame preheated on a preheat plate, for example, through a frame aligning device and transferring it to a mold of a molding device. .

[0002]

2. Description of the Related Art Generally, an electronic component such as a semiconductor chip is mounted on a lead frame, and is manufactured by resin sealing (molding) with a molding die.

FIG. 5 shows that a lead frame on which electronic components are mounted is preheated on a preheat plate, and the preheated lead frame is received and conveyed by a lead frame conveying device.
It is a schematic block diagram for demonstrating the process until it mounts | wears with a metal mold | die of a multi-plunger type | mold apparatus.

[0004] That is, the lead frame 2 on which the electronic components 1 are mounted is sequentially supplied to the preheating plate 3 through a lead frame supply section composed of a magazine or the like (not shown) or a reversing section. Are positioned and mounted so as to face each other in the longitudinal direction. The pair of lead frames 2 and 2 positioned and placed are supplied to a lead frame transport device 4 also called a loader or a loading frame via a frame alignment device (not shown).

[0005] The pair of lead frames 2, 2 are transported to a multi-plunger type molding device 5 along a preset transportation route while being supported by the lead frame transporting device 4, and are a movable type of the molding device 5. The pilot pins 51a on the lower mold 51 are positioned and mounted.

Each electronic component 1 on lead frames 2 and 2
Is housed in a cavity formed by the lower mold 51 and the upper mold 52 of the molding apparatus 5, and is molded by heating and press-fitting a sealing resin member supplied to a central pot.

In order for the chip-shaped electronic component 2 to be properly molded, the pilot pin 51 of the lower mold 51 is required.
It is necessary that the positions a and 51a be positioned with high precision.

FIG. 6A is a plan view of the lower mold 51. Pilot pins 51a, 51a are arranged in parallel at an interval Lk so as to position and mount the lead frames 2, 2 at positions indicated by broken lines. A plurality of lead frame transport devices 4 are arranged.
Thus, the pair of lead frames 2 and 2 that have been positioned and transported in advance are simultaneously received and placed as they are.

The melting and heating temperature of the sealing resin member during molding, that is, the mold temperature is often set in the range of 160 to 250 ° C., but the lower mold 51 itself has a unique linear thermal expansion coefficient. Therefore, the distance Lk between the pilot pins 51a, 51a that are erected varies depending on the set mold temperature.

Therefore, in order for the pair of lead frames 2, 2 pre-positioned and conveyed to be simultaneously and smoothly mounted on the respective pilot pins 51a, 51a of the molding apparatus 5 at the same position, the lead frames 2, 2 to be conveyed are required. The distance between the pilot pins 51 at the mold temperature is
It is necessary to match the distance Lk between a and 51a in advance.

On the other hand, since the pair of lead frames 2 and 2 transported by the lead frame transport device 4 also have a unique coefficient of linear thermal expansion, the relative positional relationship changes with temperature.

Therefore, the preheat plate 3 is used to specify the relative positional relationship between the pair of lead frames 2 and 2.
While preheating to a specific temperature, a pair of lead frames 2 and 2
Are positioned so as to correspond to the pilot pins 51a, 51a set at the interval Lk at a predetermined mold temperature Tk.

FIG. 6B shows a pair of lead frames 2 and
FIG. 2 is a plan view showing a state where 2 is positioned and mounted on the preheating plate 3, and at a preset preheating temperature Tp, an interval between a pair of lead frames 2, that is, between pilot holes 2 a and 2 a. The interval Lp is the pilot pin 51
Positioning is performed so as to coincide with the interval Lk between L.a and 51a (Lp = Lk).

Therefore, as shown in FIG. 5, the lead frame transport device 4 has two sets of openable and closable locking claws (chucks) 41, 41, and Lp = Lk on the preheat 3 in advance. Are received via the frame alignment device, transported along a transport route set in advance, and mounted on the mold 51 of the molding device 5.

On the lower die 51, the pilot holes 2a of the pair of lead frames 2 are formed.
In order to properly and smoothly insert and fit into the pilot pins 51a, 51a, naturally, the diameter of the pilot holes 2a, 2a is larger than the outer diameter of the pilot pins 51a, 51a, and there is a clearance (gap) there. However, since the size of the clearance affects the molding accuracy, it is limited to a range in which the molding is properly performed.

[0016]

As described above, in molding the electronic component 2, the distance Lk between the pilot pins 51a, 51a is specified by the set mold temperature Tk. At a preset preheating temperature Tp, the pair of lead frames 2 is positioned in advance such that the distance Lp between the pilot holes 2a, 2a matches the distance Lk between the pilot pins 51a, 51a.

Accordingly, the lead frame transporting device 4 receiving the pair of lead frames 2 and 2 via the frame aligning device keeps the state of being pre-positioned on the preheat plate and simply moves along the predetermined transport route. Just by transporting, it can be properly mounted on the mold.

However, as described above, the distance Lk between the transfer destination pilot pins 51a, 51a is changed by changing the mold temperature or changing the mold to another material having a different coefficient of thermal expansion. .

In particular, recently, many electronic components having different uses and functions have been developed, and accordingly, the form of molding has changed, and the type of the resin sealing member employed, the melting and heating temperature has been changed, or the material has been different. More and more molds are being selectively employed.

As a result, the pilot pin 5
Since the distance Lk between 1a and 51a also fluctuates, not only the positioning on the preheating plate 3 but also the work of resetting the receiving mechanism in the frame alignment device and the lead frame transport device 4 is required.

In addition, in recent years, further miniaturization of electronic parts and the like has progressed, and higher precision of positioning has been required.
Up to now, it is not easy to change the positioning setting in each device and the like, and some improvement in correspondence has been demanded.

Accordingly, the present invention corrects a change in the distance Lk between a pair of pilot pins due to, for example, a change in the material of a mold, etc., easily and with high accuracy, to provide a conventional transport route. It is an object of the present invention to provide a lead frame transfer device capable of properly mounting a lead frame at a predetermined position on a mold by transfer along the lead frame.

[0023]

According to the present invention, there is provided a lead frame transporting apparatus for transporting a lead frame while supporting the lead frame with a pair of latching claws. A holding mechanism for holding the edge in the longitudinal direction of the frame, and a position correcting mechanism for moving the locking claw on the side holding the lead frame by this holding mechanism and correcting the interval between the pair of locking claws. It is characterized by having.

As described above, according to the lead frame transport device of the present invention, since the position correcting mechanism is provided and the locking claw holding the lead frame is configured to be movable, for example, the position of the pilot pin on the mold is adjusted. Even when the lead frame is changed based on a change in mold material or a change in mold temperature, the position correction mechanism corrects the change, so that the lead frame is transported to a predetermined position on the mold so that the lead frame can be smoothly and properly adjusted. Can be positioned and mounted.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lead frame transport device according to the present invention will be described below in detail with reference to FIGS. The same components as those of the conventional lead frame transport device shown in FIGS. 5 and 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a perspective view showing an embodiment of a lead frame transport device according to the present invention, and FIG. 2 is a front view of a main part of FIG.

The lead frame transporting device 6 includes a pair of lead frames 2 and 2 received from a frame aligning device (not shown).
2 is conveyed to and mounted on a multi-plunger type molding device 5, and both edges of the lead frames 2 and 2 in the longitudinal direction are respectively provided with locking inner claws (chucks) 61 a having an L-shaped cross section. It is configured to be supported and received by the support portions 61aa and 61ba of the locking outer claw (chuck) 61b.

The locking inner claw 61a is connected to a cylinder 63 provided on the base 62, and is guided by a guide rail 62a of the base 62 by the operation of the cylinder 63, and moves in the direction of arrow X1 shown in FIG. It is configured to be movable.

Further, the locking outer claw 61b is also
By the operation of a servo motor 641 which is connected to the ball screw 64 installed above and drives the ball screw 64 to rotate, similarly, along the guide rail 62a, the arrow X in FIG.
It is configured to be movable in two directions.

The cylinder 63 and the servo motor 641
Are connected to the input device 66 via the control computer 65, so that the pair of locking inner claws 61a and locking outer claws 61b perform operation control based on a program built in the control computer 65 in advance. In response to this, as shown in FIG. 2, the opening and closing operations are performed by moving in opposite directions to each other, and the lead frame 2 is received and delivered.

A vertically moving cylinder 67, which operates under the control of the control computer 65, is attached and fixed to the locking outer pawl 61b.
71 descends, and the holding member 672 provided at the lower end portion
Is configured to be able to press and hold one edge in the longitudinal direction of the lead frame 2 supported between the locking inner and outer claws 61a and 61b between the locking and outer claws 61b and the supporting portion 61ba of the locking outer claw 61b. I have.

The lead frame transfer device 6 of this embodiment receives and transfers lead frames 2 and 2 preheated on a preheat plate through a frame aligning device, as in the prior art. When the position of the pilot pin 51a in 5 changes, the change is corrected by the operation of the control computer 65, and the lead frames 2 and 2 are transported along the same transport route as before, and are appropriately mounted on the molding apparatus 5.

That is, the positions of the pilot pins 51a, 51a in the lower mold 51 shown in FIG.
Considering the relationship between the positions of the pair of lead frames 2 and 2 positioned on the preheater plate 3 shown in FIG. 3B, first, regarding the lower mold 51 shown in FIG.
When the distance between a pair of opposed pilot pins 51a at normal temperature (20 ° C.) is A20, the mold temperature is Tk, and the linear thermal expansion coefficient of the lower mold 51 is αk, the mold temperature is 0 ° C. A pair of pilot pins 51a, 51a at Tk
The interval (distance) LkTk between them is represented by the following equation (1).

LkTk = A20 [1 + αk (Tk−20)] (1) On the other hand, with respect to the preheater plate 3 shown in FIG. 3B, a pair of lead frames positioned on the preheater plate 3 at normal temperature (20 ° C.) The distance between the centers of 2, 2 is B
20, the distance between the center position of each lead frame 2, 2 and its pilot hole 2a is C20, the preheating temperature of the preheater plate 3 is Tp, and the linear thermal expansion coefficient of the preheater plate 3 is αp. The interval (distance) LpTp between the pilot holes 2a, 2a of the pair of frames positioned on the preheater plate 3 is:
It is represented by the following equation (1).

LpTp = [B20 (1 + αp (Tp−20))] + [2 × C20 (1 + αp (Tp−20))] (2) Therefore, from the above equations (1) and (2), the preheat plate 3 , A pair of lead frames 2, 2 positioned at the interval LpTp at the preheating temperature Tp, and the interval Lp at the mold temperature Tk.
In order to be properly positioned and inserted into the pilot pins 51a, 51a of kTk, it is required that LpTp = LkTk.

Therefore, under the condition of LpTp = LkTk, the material of the lower mold 51 is changed to make the linear thermal expansion coefficient αk.
Is changed to αK, and when the distance LKTK between the pilot pins 51a, 51a in the lower mold 51 at that time, the positional deviation from the previous positioning interval LpTp by the difference E (= LkTk to LKTK) is obtained. Occurs.

Therefore, in this embodiment, the difference E
(= LkTk to LKTK) is calculated by the above equation (1).
The control computer 65 calculates the difference E from the value of k and the value of LKTK calculated by substituting αK for αK in equation (1), and outputs a correction control signal corresponding to the difference E to the servo motor. 641.

That is, specifically, with respect to the lower mold 51 side, the pilot pins 51a, 5a at normal temperature (20 ° C.)
Since the interval A20 of 1a and the linear thermal expansion coefficients αk and αK are both known values, by inputting the data of the measured mold temperature Tk to the input device 66 during the setting, the control computer 65 The distances LkTk and LKTK between the pair of pilot pins 51a, 51a can be obtained by the calculation based on the equation (1).

On the other hand, with respect to the preheat plate 3, at room temperature (20 ° C.), the distance C20 between the center position of each lead frame 2, 2 and each pilot hole 2a, the linear thermal expansion coefficient αp of the preheat plate 3, etc. Since both are known values, the pilot holes 2 of the pair of lead frames 2 at the set or measured preheating temperature Tp
a, 2a (ie, pilot pin 5
The distance B20 between the centers of the pair of lead frames 2, 2 corresponding to the distance LkTk between 1a and 51a) is obtained from the above equation (2) and positioned in advance.

As described above, the control computer 6
5 by calculation of the difference E (= LkTk to LKTK) between the pair of lead frames 2 and 2, a half of each lead frame 2 is calculated.
The servo motor 641 can be driven so as to perform the position correction of (= E / 2).

After the positioning of the pair of lead frames 2 and 2 on the preheat plate 3 in this manner, the mold device 5 is changed to a mold of a material having a different coefficient of thermal expansion. Pilot pin 51
Even if the distance Lk between a and 51a changes, the control computer 65 calculates the amount of misregistration correction corresponding to the change, and the control computer 65 on the side holding the lead frame 2 so that the change becomes zero. Since the movement of the locking claws is corrected, the lead frame transport device 6 can appropriately mount the pair of lead frames 2 and 2 on the pilot pins 51a and 51a on the mold.

Next, under the control of the control computer 65, the lead frame transporting device 6, which has received and supported the pair of lead frames 2 and 2 from the frame aligning device, has a difference of 1/2 of the difference E per one lead frame 2. The procedure for correcting only the difference will be described with reference to FIGS. In the following description, one of the pair of lead frames 2 and 2 will be described, but the same applies to the other. First, the control computer 65 operates the cylinder 63 and the servo motor 641 to
As shown in (a), when the locking inner and outer claws 61a and 61b are opened and the table 7 of the frame aligning device on which the lead frame 2 is positioned and placed is pushed up, the lead frame 2 is opened and locked. Claws 61a, 61
b.

Next, the control of the cylinder 63 and the servomotor 641 by the control computer 65 causes
As shown in (b), the left and right edges of the lead frame 2 in the longitudinal direction are the support portions 61 of the locking inner and outer claws 61a, 61b.
aa, 61ba, and the inner and outer pawls 61a,
As shown in FIG. 4 (c), the table 7 of the frame aligning device is lowered in the direction of arrow Y1, so that the lead frame 2 has the support portions 61aa, 6aa at both edges.
Supported at 1ba.

Next, the control computer 65 controls the vertical moving cylinder 67 to lower the pressing member 672 in the direction of arrow Y2 as shown in FIG. The claw 61b is pressed and held between the claw 61b and the supporting portion 61ba.

Here, as described above, the control computer 65 operates the servo motor 641 by a value equal to の of the calculated positional deviation correction amount E, and moves the servo motor 641 in the direction of the arrow X in FIG. The position of the pilot hole 2a in the lead frame 2 and the position of the pilot pin 51a of the lower die 51 of the linear thermal expansion coefficient αK can be matched by moving the locking outer claw 61b.

In the above description, the gap between the pair of pilot pins 51a, 51a is shifted due to the change of the material of the lower die 51 in the molding apparatus 5. In other words, on the receiving side of the lead frames 2a, 2a, for example, the interval between the pilot holes of the pair of lead frames 2a, 2a positioned on the preheating plate 3 corresponds on the lower mold 51 on the receiving side. According to the difference (shift) between the interval between the pair of pilot pins 51a, 51a, the position is corrected in the direction in which the difference becomes zero and the transfer is performed, so that the conventional transfer route is not changed. It can be easily and properly matched.

Therefore, according to the present invention, not only the case of changing the material of the lower mold 51, but also changing the temperature of the mold, changing the position of the pilot pin 51a by replacing the mold itself,
Further, the present invention can be widely applied to a change in the position between the pilot holes 2a, 2a of the pair of lead frames 2, 2 positioned and mounted on the preheat plate 3.

In the above embodiment, the ball screw 6
4, the pressing member 672 and the locking outer pawl 61b move together to form a position correction mechanism. However, a separate pin is erected on the support portion 61ba of the L-shaped locking outer pawl 61b. The pilot holes 2a of the lead frame 2 may be fitted to and held by the pins.

In the above configuration, the locking outer claw 61b
Side, the lead frame 2 is held to perform positioning correction, but instead of the locking outer claws 61b, the locking inner claws 61 are used.
Needless to say, it may be performed on the a side.

In any case, according to the lead frame transport device of the present invention, the lead frames 2, 2 to be received and transported are calculated by the control computer 65.
Since the distance between them can be easily and accurately corrected, a remarkable effect can be obtained in practical use.

[0051]

As described above, the lead frame transport device of the present invention can be used for receiving and transporting lead frames.
Since the relative position interval between the pair of lead frames can be corrected, for example, the present invention can be applied to the transfer of a lead frame to a molding apparatus, and can exhibit excellent effects in practice.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a lead frame transport device according to the present invention.

FIG. 2 is a front view of a main part of the device shown in FIG.

FIG. 3A is a plan view showing a state in which a pair of lead frames conveyed by the apparatus shown in FIG. 1 are mounted on a preheating plate, and FIG. 3B is a plan view showing FIG. FIG. 3 is a plan view of a lower mold of a mold on which a pair of lead frames shown are conveyed and placed.

FIGS. 4 (a) to 4 (e) are explanatory views showing a procedure in which the device shown in FIG. 2 receives a lead frame and corrects its position.

FIG. 5 is a configuration diagram illustrating a situation in which a conventional lead frame transport device receives a lead frame on a preheat plate and transports and mounts the lead frame on a molding device.

6A is a plan view showing a state in which a pair of lead frames carried by the lead frame carrying device shown in FIG. 5 are placed on a preheating plate, and FIG. 6B is a plan view showing FIG.
FIG. 4 is a plan view of a lower mold of a mold on which a pair of lead frames shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic component 2 Lead frame 2a Pilot hole 3 Preheat plate 4 Lead frame transfer device 5 Molding device 51 Lower die 51a Pilot pin 6 Lead frame transfer device 61a Locking inner claw (locking claw) (supporting portion) 61aa Supporting portion 61b Locking outer claws (locking claws) (supporting portion) 61ba supporting portion 62 base 63 cylinder 64 ball screw (position correcting mechanism) 641 servo motor (position correcting mechanism) 65 control computer (position correcting mechanism) 66 input device 67 Vertical cylinder mechanism (holding mechanism) 671 Plunger 672 Push member

Continued on the front page F term (reference) 3C007 DS06 ES03 ET08 EU01 EV05 EV23 EW03 HS27 KS03 NS09 NS17 3F059 AA01 AA04 BA08 CA06 DA02 DA08 DC07 FB16 FB17 FB29 FC05 FC06 3F061 AA04 BA03 BB08 BC01 BD04 BE05 BE43 BF04 DB04 DB04

Claims (5)

[Claims] 1. A lead frame transport device for transporting a lead frame while supporting the lead frame with a pair of locking claws, wherein one of the locking claws supporting the lead frame is used to remove an edge in the longitudinal direction of the lead frame. A lead comprising: a holding mechanism for holding; and a position correcting mechanism for moving a locking claw on the side holding the lead frame by the holding mechanism and correcting a gap between the pair of locking claws. Frame transport device. 2. The lead according to claim 1, wherein the pair of locking claws are formed so as to be openable and closable, and are configured to support the lead frame in a closed state. Frame transport device. 3. The lead frame according to claim 1, wherein the pair of locking claws are configured to receive the lead frame from a frame alignment device and to convey the lead frame to a molding device. Transport device. 4. The position correcting mechanism is configured to correct the distance between the pair of locking claws in accordance with a change in the position of a pilot hole or a change in the position of a pilot pin in the molding apparatus. The lead frame transport device according to claim 3, wherein: 5. The lead frame transport device according to claim 1, wherein the correction by the position correction mechanism is performed by computer control.