JP2615789B2 - Lead frame transport mechanism - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport mechanism for horizontally extracting a lead frame stacked and stored in a magazine and transporting the lead frame to a next step such as a mold apparatus.

"Prior art" For example, in a transfer molding apparatus that forms a resin package on a lead frame after wire bonding, a transfer mechanism for automatically supplying the lead frame into the mold according to the molding cycle is provided. There is.

Conventionally, as a transport mechanism of this type, a configuration in which both side edges of a central portion of a lead frame placed in a horizontal state are sandwiched between a pair of supporting claws and the supporting claws are moved has been widely used.

[Problems to be Solved by the Invention] However, in the above-described transport mechanism, since both side edges of the lead frame are sandwiched with a force that does not cause the lead frame to fall, it is inevitable that the lead frame slightly bends in the width direction. ,
At this time, the wire may be subjected to tension due to stress, and the bonding surface may be peeled off, or the wire may be broken.

Further, in the above-described mechanism, when the dimensions of the lead frame are changed, the dimensions and the locking width of the support claws must be reset each time, and there is a problem that the versatility is poor.

The present invention has been made in view of the above circumstances, and conveys a lead frame without bending, so that a wire on the lead frame does not peel or break, and also, a dimensional change of the lead frame. It is an object of the present invention to provide a versatile lead frame transport mechanism that can respond.

Means for Solving the Problems The present invention for achieving the above object is a lead frame transport mechanism for transporting a lead frame in the longitudinal direction while supporting both ends of the lead frame in the longitudinal direction. A first claw support and a second claw support, each of which is provided with an upper claw and a lower claw that can be opened and closed and that are opposed to each other in the longitudinal direction, and each of the first claw support and the second claw support Claw opening / closing means for individually opening and closing the claws, and each claw support are separately provided such that the claws of the first claw support and the second claw support maintain rectangular opposing sides on the same horizontal plane. And a driving means capable of moving in the longitudinal direction.

[Operation] In the transport mechanism of the present invention, the upper claw and the lower claw of the second claw support horizontally sandwich the element gap at the front end of the lead frame, and open the upper and lower claws of the first claw support. Then, the rear end of the lead frame is placed horizontally on the lower claw, and in this state, each claw support is moved in the same direction to convey the lead frame. This makes it less likely that stress will be applied to the lead frame, as compared to the case where the lead frame is transported while being sandwiched between the support claws in the width direction, and can prevent troubles such as wire peeling and disconnection.

Hereinafter, a transfer molding apparatus employing an example of a lead frame transport mechanism according to the present invention will be described with reference to the drawings.

First, an outline of the entire molding apparatus will be described with reference to FIGS. 1 is a front view of the apparatus, FIG. 2 is a plan view, FIG. 3 is a right side view, and FIGS. 4 and 5 are a right side view and a left side view with a cover attached. The front, rear, left and right used in the description are based on the state when the apparatus is viewed from the front.

In the figure, reference numeral 1 denotes a magazine mounting table fixed on a base 2, on which a plurality of cuboid magazines M are arranged at equal intervals. Reference numeral 3 denotes a mounting table 1 for the magazine M.
This is a magazine transfer mechanism that lifts one unit at a time and transfers it onto the turntable 4.

The turntable 4 is capable of mounting the magazine M eccentrically from the rotation axis. For convenience of explanation, the position near the magazine mounting table 1 (P1 in the figure) is the mounting position, and the opposite side (P2) is the half-rotation position. Called. Reference numeral 5 denotes a frame pushing mechanism, which pushes out the lead frames L one by one from the magazine M in P1 or P2. Extruded lead frame L
Are transferred into the transfer mold 8 by the frame transfer mechanism 6 together with the resin tablets T sequentially supplied from the tablet supply mechanism 7. Behind the transfer die 8, a cleaning mechanism 9 for cleaning the opposing surfaces of the upper die and the lower die is provided.

The lead frame L with the cull in which the resin package is formed by the transfer mold 8 is separated from the cull by the gate break mechanism 10, and is sequentially stored in the rack 12 by the product storage mechanism 11.

Next, referring to FIGS. 6 to 11, the magazine transfer mechanism 3, the turntable 4, and the magazine transfer mechanism 3, which are closely related to the present invention, will be described.
The frame pushing mechanism 5 and the frame transport mechanism 6 as a main part of the present invention will be described in detail. Note that Magazine M
As shown in FIG. 6, a pair of side plates 13 having a large number of horizontal grooves 13A formed inside, and a bottom plate 14 connecting the upper and lower ends of these side plates 13 are formed along the horizontal grooves 13A. A predetermined number of lead frames L are stored in a stack.

As shown in FIG. 7, a ball screw 15 extending beyond the turntable 4 is horizontally disposed above the magazines M on the mounting table 1, and its front end is connected to a stepping motor 16.

A chuck support 18 is attached to the ball screw 15 via a ball nut 17, and the chuck support 18 extends along a horizontal rail 21 supported by a fixed plate 20 via rail receivers 19 at both ends. It is slidable.

The chuck support 18 has an air cylinder at its center.
The guide bar 23 penetrates vertically and slidably at both ends, and the rod of the air cylinder 22 and the lower end of each guide bar 23
Has been fixed. An air chuck 25 having a pair of holding claws 25A facing downward is fixed to the elevating plate 24, and is held between the upper end of the center of the magazine M by air supply.

On the other hand, as shown in FIG. 1, the turntable 4 is horizontally fixed on an air rotary drive 26, and the air rotary drive 26 is a traveling drive having a built-in stepping motor and the like.
27, which is rotated 180 degrees forward and backward by air supply, and can be raised and lowered with high precision. On the upper surface of the turntable 4, a partition 4A that separates the mounting position P1 from the half-rotation position P2 is fixed.

Next, the lead frame pushing mechanism 5 will be described. As shown in FIG. 7, an extrusion support plate 28 is disposed in front of the turntable 4 along the longitudinal direction of the magazine M.
The air cylinder 29 fixed above can move forward and backward along the pair of guide bars 30 toward the turntable 4. Ball screws 32 are supported in parallel at both ends of the extrusion support 28 via bearings 31, and are driven to rotate by a stepping motor 33. An arm support 35 is attached to the ball screw 32 via a ball nut 34, and is slidable along a guide bar (not shown).

An arm 36 composed of a horizontal portion 36A and a vertical portion 36B extending downward from the tip is attached to the arm support 35, and when the ball screw 32 is rotated with the rod of the cylinder 29 protruding, When the lower end of the arm vertical portion 36B pushes out one lead frame L from the magazine M at P1 (see FIG. 8), when the rod of the cylinder 29 is retracted, the lead frame L is moved from the magazine M at P2. Is pushed out one sheet.

 Next, the frame transfer mechanism 6 will be described.

As shown in FIG. 10 and FIG.
2, two guide bars 40 are arranged in parallel along the lead frame lead-out direction, pass behind the mold 8 and are fixed at the right end of the device. Further, two ball screws (driving means) 41 are arranged in parallel with the guide bars 40.
And are driven by different stepping motors (not shown).

A first claw support 42 and a second claw support 43 are attached to the guide bar 40 and the ball screw 41 in order from the one closer to the turntable 4. These nail supports
42 and 43 are L-shaped, and the guide bar 40
And the ball screw 41 is inserted, and is engaged with only one of the ball screws 41 via the ball nut 44. Therefore, the first claw support 42 and the second claw support 43
Each is driven by a separate ball screw 41.

A servo motor 45 is fixed to the right side surface of each of the claw supports 42 and 43, and a pinion 46 is fixed to a rotation shaft of the servo motor 45. 11, a pair of rack members 47 are horizontally supported by bosses 48, respectively, in the horizontal portions of the claw supports 42 and 43, and the rack members 47 are respectively provided at the upper end and the lower end of the pinion 46. Are engaged.

Further, a twin rod cylinder 49 is fixed downward at one end to each of the rack members 47,
The other end is inserted through a cylindrical body 50 fixed horizontally to the opposite twin rod cylinder 49. Thus, when the pinion 46 is rotated in the direction of the arrow in the figure, the twin rod cylinders 49 simultaneously open and close to the position indicated by the two-dot chain line in the figure.

At the lower end of the rod of each twin rod cylinder 49, a chuck cylinder having an upper claw 51A and a lower claw 51B extending horizontally.
52 are mounted facing each other. When air is supplied to each chuck cylinder 52 with the rod of the twin rod cylinder 49 lowered, the upper claws 51A and the lower claws 5
1B close to each other and the closed surface is the mold split surface PL
To match the height. Thus, the first
The claw support 42 and the second claw support 43 each include a pair of twin rod cylinders 49 and 49 as claw opening / closing means, respectively, and each claw of the first claw support 42 and the second claw support 43 is individually It can be opened and closed.

A tablet transfer mechanism is also provided on the lower surface of the second claw support 43.
53 are provided. The tablet transfer mechanism 53 holds a plurality of tablets T arranged in a line on the tablet mounting table 54 by the tablet supply mechanism 7 and a pair of clamp plates.
In the state shown in FIG. 5, the sheet is inserted into the mold 8 together with the lead frame L and dropped into a resin pot formed in the lower mold.

 Next, a method of using the above device will be described.

In this transport mechanism, first, as shown in FIG. 7, the ball screw 15 is rotated to move the chuck support 18 onto the magazine M on the mounting table 1, and the air cylinder 22 is operated to lower the air chuck 25. Then, the magazine M is sandwiched by the claws 25A. Next, the magazine M is lifted and moved to the mounting position P1 of the turntable 4, where the magazine M is mounted.

After the magazine M is loaded, the height of the turntable 4 is adjusted as required so that the lower end of the push arm 36 is slightly lower than the lead frame L at the top in the magazine M. Then, with the rod of the cylinder 29 protruding, the pushing arm 36 is moved to push out one lead frame L from the magazine M at P1, and the tip of the lead frame L is closed by the first claw support 42. Upper nail 51
Stop lightly on the side of A and the lower claw 51B. By this operation, the lead frame L is accurately positioned.

Next, the upper claws 51A and the lower claws 5 with which the lead frame L has been brought into contact.
1B, the first claw support 42 is moved to the turntable 4 side, and the lead frame L is moved between the upper claw 51A and the lower claw 51B.
Through a predetermined length to sandwich a gap portion of the element. Then, in this state, the first claw support 42 is replaced with the second claw support 43.
Side, and completely pull out the lead frame L from the magazine M. At the same time, pass the lead frame L by a predetermined length between the claws 51A and 51B of the second claw support 43, and
The element is fixed by sandwiching the element gap between 51A and 51B. Then, the pawls 51A and 51B of the first pawl support 42 are opened and returned to the initial position.

Next, the turntable 4 is rotated halfway by the air rotary drive 26 to move the magazine M to the half-rotation position P2, and the lift drive 27 further moves the turntable 4 to the interval of the stacking of the lead frames L in the magazine M. To raise. Then, the rod of the cylinder 29 is retracted, the extruding arm 36 is moved again, and from the magazine M at the half rotation position P2,
The top lead frame L is extruded in the same direction as above. Thereafter, the same operation as that of the first sheet is performed with the claws 51A, 51B,... On the opposite side to the previous sheet. The lead frames L are inserted one by one, and the other ends of the lead frames L are supported by the lower claws 51B of the first claw support 42.

After supporting the two lead frames L in this manner, the rods of all the twin rod cylinders 49 of each claw support 42, 43 are retracted, and each lead frame L is raised while being held in a horizontal state. The lower end of 51B is made slightly higher than the split plane PL of the mold. Then, after simultaneously moving the second claw support 43 and the first claw support 42 onto the lower mold of the mold 8, each chuck cylinder 52 is further lowered, and the positioning holes formed in the lead frame L are removed. Is fitted to a positioning projection formed on the upper surface of the lower die. Then, after the claws 51A and 51B of the second claw support 43 are opened, the respective servomotors 45 are energized to open the claws 51A and 51B to both sides, and the lead frames L are released and set on the lower mold. Complete.

When the above one cycle is completed, the turntable 4 is raised again by the lead frame laminating interval in the magazine M and is rotated half a turn, and the above cycle is repeated from the beginning.

When the magazine M is empty, the empty magazine M, which has been moved to the mounting position P1 by operating the magazine transfer mechanism 3, is returned to the original mounting table 1, and a new magazine is transferred from the mounting table 1. The magazine M is brought in and placed at the mounting position P1, and the cycle is continued.

According to the lead frame transport mechanism described above, one end of the lead frame L is sandwiched in the thickness direction by the upper claws 51A and the lower claws 51B of the second claw support 43, and the other end is connected to the first claw support 42. Since the lead frame L is transported while being supported on the lower claw 51B, the lead frame L does not bend in any of the width direction and the longitudinal direction, and compared with a conventional transport mechanism that sandwiches the lead frame in the width direction. Stress is not easily applied to the lead frame, and troubles such as peeling or disconnection of the wire can be effectively prevented.

In addition, since the lead frame is sandwiched horizontally by the upper and lower claws, even if the dimensions of the lead frame are changed, it is necessary to change the dimensions of the claws and the amount of opening / closing operation as in the conventional transport mechanism. There is almost no, and it is excellent for general use. Further, in this example, since the lead frame is conveyed by the ball screw whose movement amount can be set arbitrarily, there is an advantage that it is possible to easily cope with lead frames of all dimensions only by changing the operation program.

In the above-described embodiment, the claw support members 42 and 43 are horizontally moved along the same guide bar 40. However, the claw support members 42 and 43 may be moved in parallel in a vertical direction or an inclined direction. Further, the configuration and operation of each of the other units may be appropriately changed as needed.

[Effect of the Invention] As described above, in the lead frame transport mechanism of the present invention, the element gap portion at one end of the lead frame is moved to the second position.
Since the upper and lower claws of the nail support are sandwiched in the thickness direction and the other end is placed on the lower nail of the first nail support and transported horizontally, the lead frame can be moved in either the width direction or the longitudinal direction. It is less likely to bend, and less stress is applied to the lead frame compared to the conventional transport mechanism that sandwiches the lead frame in the width direction, effectively preventing problems such as peeling or disconnection due to tension on the wire. Can be. Also,
Even when the dimensions of the lead frame are changed, there is almost no need to change the dimensions of the claws and the amount of opening / closing operation unlike the conventional transport mechanism, and the versatility is excellent.

[Brief description of the drawings]

1 to 5 show an overall schematic view of a transfer molding apparatus employing an example of a lead frame transport mechanism according to the present invention. FIG. 1 is a front view, FIG. 2 is a plan view, and FIG.
The figures are a right side view, and FIGS. 4 and 5 are a right side view and a left side view with a cover attached. FIG. 6 is a perspective view of a magazine, FIG. 7 is a plan view showing a magazine transfer mechanism and a frame pushing mechanism, FIGS. 8 and 9 are side and front views showing the magazine transfer mechanism, FIGS. FIG. 11 is a plan view and a side view showing a lead frame transport mechanism of a main part of the present invention. L: Lead frame, M: Magazine, 6: Lead frame transport mechanism, 40: Guide bar, 41: Ball screw (drive mechanism), 42: First claw support, 43: Second claw Support, 45 ... Servo motor, 46 ... Pinion, 47 ... Rack member, 49 ... Twin rod cylinder, 51A ... Top jaw, 51B ... Bottom jaw, 52 ... Chuck cylinder.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-12541 (JP, A) Japanese Utility Model Sho 55-106541 (JP, U) Japanese Utility Model Utility Model Sho-53-1223464 (JP, U)

Claims (1)

(57) [Claims] 1. A lead frame transport mechanism for transporting a lead frame in the longitudinal direction while supporting both ends in the longitudinal direction, the lead frame comprising an upper claw and a lower claw which extend horizontally and can be opened and closed. A first claw support and a second claw support opposing each other in the longitudinal direction; claw opening / closing means for individually opening and closing each claw of the first claw support and the second claw support; Driving means for individually moving each claw support in the longitudinal direction so that each claw of the first claw support and the second claw support keeps a rectangular opposing side position on the same horizontal plane; A lead frame transport mechanism.