JPH0467783B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an external lead bonding method for bonding external leads of a solid device punched from a film carrier to lead bonding portions of a lead frame or a substrate.

[Prior Art] As shown in FIG. 8, an external lead bonding device has the following features:
A solid device 2 supported by an external lead 2a is punched out on a film carrier 1 having sprocket holes 1a on both side bands, and a lead joint part of a lead frame 3 shown in FIG. 9 or a board 4 shown in FIG. 10 is formed. External lead 2a to 3a or 4a
11 and 12, align and place the external leads 2a and lead joints 3.
The process of joining a and a by bonding is carried out fully automatically. Hereinafter, the term lead frame refers to both the lead frame 3 and the substrate 4.

Conventionally used external lead bonding devices can be roughly divided into two types. The first method is to arrange the film carrier and lead frame one above the other,
This is a method in which a solid device on a film carrier is punched out and at the same time it is thermocompression bonded to the lead frame above it.The other second method is to arrange the film carrier and lead frame in parallel, and then punch out the solid device on the film carrier. In this method, a device is punched out, this solid device is suctioned by a vacuum suction head, transferred and placed on a lead frame, and then bonded using a separate bonding device. The present invention is directed to this second method.

In order to correctly position the punched solid device on the lead frame, it is necessary to recognize the positional shift of the external lead of the solid device using a camera. For this reason, conventionally, light is irradiated directly onto the external leads of a punched solid device, and the image reflected from the surface of the external leads is captured by a camera.

[Problems to be Solved by the Invention] Since the external lead 2a of the solid device 2 is easily changed in position by being cut by punching, when an image of directly irradiated light reflected from its surface is viewed with a camera, the brightness may vary. This tends to cause unevenness in the image size, and attempts to automatically recognize its position often result in recognition errors.

An object of the present invention is to provide an external lead joining method that allows highly accurate positioning.

[Means for solving the problem] The problem with the above-mentioned conventional technology is that light is projected onto the camera so as to pass through the solid device held in the vacuum suction head from below, and the image of the shadow of the external lead due to this transmission is captured. Captured by a camera, this is processed by the recognition unit to calculate the relative positional deviation with the lead frame position, and this is fed back to the movement control system of the XY direction movement table for solid device transfer to read the solid device. This is solved by positioning the frame at a predetermined position.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. As shown in FIGS. 1 to 3, this device includes a frame body including a main body 10 and a control case 11 provided on the upper surface thereof. Inside the main body 10, a film carrier 1 supply/storage device 12 is provided.

A supply reel 14 rotatably supported by the main body 10 is provided on the supply side of the supply and storage device 12 of the film carrier 1, and a take-up reel 15 is provided on the storage side. The supply reel 14 and take-up reel 15 are each rotated by a synchronous motor (not shown). The supply reel 14 is wound with a spacer tape 16 that prevents the film carrier 1 and the solid device 2 from being overlapped and damaged during winding.

A sizing feeding device 20 is provided on the top surface of the main body 10 to feed the film carrier 1 sent from the supply/storage device 12 by a sizing amount. Sizing feed device 20
A pair of sprockets 22 and 23 (not shown) are rotatably supported on a support base 21 provided on the upper surface of the main body 10 on the traveling path of the film carrier 1 unreeled from the supply reel 14. It is equipped with a sprocket rotation synchronous motor (not shown) that rotates these two sprockets 22, 23 synchronously by means of a belt transmission means, and is provided on the outer periphery of the sprockets 22, 23 in the sprocket hole 1a (see FIG. 8) of the film carrier 1. When the sprocket rotation synchronous motor engages with the teeth, the film carrier 1 can be sequentially fed in fixed-length increments by constant-angle intermittent rotation of the sprocket rotation synchronous motor.

Further, a punch unit 30 for punching out the solid device 2 on the film carrier 1 is provided on the upper surface of the main body 10, and is attached to the sizing feeding device 20. The punch unit 30 includes a punching actuator 31 that is provided along a fixed-length feed path of the film carrier 1 connecting the sprockets 22 and 23, and punches the solid device 2 with a punching tool while clamping the film carrier 1. A direct-acting cam follower 32 provided below the punching actuator 31 to raise and lower it.
and the air cylinder 3 that comes into contact with this and raises and lowers it.
3 and a linear cam 34 that reciprocates.

Further, a feeding device 35 is provided on the upper surface of the main body 10 for feeding the lead frame 3 intermittently by a fixed distance using a well-known claw type or belt type conveying means. Further, although not shown, separate conveying means are provided on the supply side and the discharge side of the feeding device 35, respectively, so that a large number of lead frames 3 can be automatically fed sequentially.

Further, a film carrier 1 is provided on the top surface of the main body 10.
A transfer arm device 40 is provided for transferring the solid device 2 punched from the solid device 2 to a predetermined position on the lead frame 3. This transfer arm device 40
2, 4, and 5, an X-direction guide rail 41 provided on the upper surface of the main body 10 and extending along a direction (X direction) parallel to the traveling path of the film carrier 1. , an X-direction moving table 43 that is fed along this by a feed motor 42 via a well-known feed screw mechanism, and an X-direction moving table 43 that is provided on the A first Y-direction guide rail 44 that extends, a first Y-direction moving table 46 that is fed along this by a feed motor 45 via a similar feed screw mechanism, and a first Y-direction moving table 46 that extends.
A second section is provided above and also extends along the Y direction.
A 2Y-direction guide rail 47, a second Y-direction moving table 49 sent along this by a feed motor 48 via a feed screw mechanism, a lifting rail 50 provided on the second Y-direction moving table 49, and a An elevating table 51 that can be raised and lowered, a linear cam 53 that is reciprocated by an air cylinder 52 for raising and lowering the elevating table 51, and a Y
A lifting arm 54 extending along the direction and a vacuum suction head 55 provided at the tip of the lifting arm 54.
It becomes more. By moving the X- and Y-direction moving tables 43, 46, and 49, the vacuum suction head 55 can advance directly above the punch unit 30, and pick up the solid device 2 punched by the punching tool. It is designed to be able to be adsorbed and held as is.

Further, an optical device 60 is provided on the upper surface of the main body 10 to confirm the position of the solid device 2 when the transfer arm device 40 is transferring the solid device 2 . As shown in FIGS. 1 to 3 and 6, this position confirmation optical device 60 determines the position of the solid device 2 transferred by the transfer arm device 40 when it is attracted to the vacuum suction head 55. It consists of a device for checking the deviation itself and a device for checking the deviation of the lead frame 3 sent by the lead frame 3 feeding device 35 from the reference position. The former includes a camera 61 provided directly above the transfer path of the solid device 2, a prism 62 provided directly below the camera 61, and a light projector 63 that refracts light with the prism 62 and projects it onto the camera 61.
The latter includes a camera 7 installed directly above a predetermined first bonding station provided along the conveyance path of the lead frame 3.
4, and a light projector 65 that reflects light onto the lead frame 3 and projects it onto the camera 64.

Further, on the upper surface of the main body 10, there are two first and second bonding devices for bonding the solid device 2 transferred onto the lead frame 3 with a bonding station provided along the conveyance path of the feed device 35 of the lead frame 3. 70 and 71 are provided. The bonding devices 70 and 71 are
A bonding device is provided for the first bonding station described above and a second bonding station adjacent thereto, which is also provided on the conveyance path of the lead frame 3, and extends from a well-known bonding head and moves up and down. A bonding tool 73 having a relief portion 73a in the center is fixed to the tip of the arm 72, as shown in FIG. This bonding tool 73 is
It is possible to bond the external leads 2a provided on two opposing sides of the solid device 2 while avoiding interference by straddling the main body of the solid device 2.
In the first bonding device 70 provided in the first bonding station, the relief portion 73a of the bonding tool 73 is provided so that the vacuum suction head 55 can also escape, and the second bonding device 70 provided in the second bonding station In the bonding device 71, the relief portion 73a of the bonding tool 73 is provided perpendicularly to that of the first bonding device 70.

Next, the operation of the external lead bonding device having such a configuration will be explained. When the film carrier 1 is unwound from the supply reel 14, it is fed by sprockets 22 and 23 by a fixed length. At this time, the synchronous motor rotates intermittently in synchronization with the sprocket rotation synchronous motor to prevent excessive tension from being applied to the film carrier 1 or from causing slack. When the film carrier 1 is fed a fixed distance and the solid device 2 is positioned at a predetermined position on the punching actuator 31 of the punch unit 30, the air cylinder 33 is operated and the linear cam 34 is moved to the right side. The linear-acting cam follower 32 rises, pushes up a punch (not shown) of the punching actuator 31, and after the film carrier 1 is clamped and fixed by a well-known mechanism, the solid device 2 is punched upward by the punching tool. Pull it out. At this time, the solid device 2 is placed on the punching tool separated from the film carrier 1.

Next, the XY table is moved by the rotation of the feed motors 42, 45, and 48, and the vacuum suction head 55 provided at the tip of the lifting arm 54 is positioned directly above the solid device 2. Then, when the air cylinder 52 operates and the linear cam 53 retreats, the elevating table 51 descends, whereby the elevating arm 54 also descends and the vacuum suction head 55 suction-holds the solid device 2. After this, air cylinder 52
When the linear cam 53 moves forward, the lifting platform 51 rises, and the lifting arm 54 lifts the solid device 2.
hold and rise.

Then, the XY table operates again to move the lifting arm 54 and position the solid device 2 below the optical device 60 for confirming its position. At this time,
The light emitted from the light projector 63 is refracted by the prism 62 and is projected onto the camera 61 so as to pass through the solid device 2 from below. In this image using transmitted light, the external lead 2a, the solid device 2
is reflected as a shadow, the contrast becomes clear, and errors in automatic recognition by the camera 61 are extremely unlikely to occur, which is convenient. In this way camera 6
The image captured in step 1 is processed by a recognition unit (not shown), and at the same time, an image of the lead frame 3 obtained by reflecting the light emitted from the light projector 65 on the surface of the lead frame 3 and projecting it onto the camera 64 is obtained. are also processed by the same recognition unit, and based on the recognition result of these two positional deviations, feedback is given to the rotation amounts of the feed motors 42, 45, and 48 so as to correct the deviations. As a result, the lifting arm 54 moves further to correctly position the solid device 2 directly above the predetermined position of the lead frame 3.

When the positioning is completed, the air cylinder 52 operates again, the linear cam 53 retreats, the elevating arm 54 descends, and the vacuum suction head 55 correctly places the solid device 2 at a predetermined position on the lead frame 3. Hold this while pressing lightly downwards. Then, in this state, the bonding arm 72 of the first bonding device 70 is lowered by a well-known mechanism, and the bonding tool 73 escapes both the solid device 2 and the vacuum suction head 55 through the relief part 73a and interferes with the The external leads 2a provided on two opposing sides of the solid device 2 are bonded to the lead frame 3 at the same time while avoiding the above.

Thereafter, when the bonding arm 72 rises, the vacuum suction head 55 also stops adsorbing the solid device 2, rises, and advances above the punch unit 30 to repeat the series of operations again. On the other hand, the solid device 2 to which half of the external leads 2a have been bonded is intermittently fed by the feeding device 35 to the second bonding station, where it is bonded to the second bonding station in exactly the same way as the first bonding device 70. The device 71 connects the external leads 2a on the other two opposing sides to the lead frame 3.
At this point, bonding of the external leads 2a is completed.

Now, film carrier 1 is punch unit 3.
When it passes through 0, it passes through the sprocket 23 and is taken up on the take-up reel 15 together with the spacer tape 16.

[Effects of the Invention] As is clear from the above description, according to the present invention, both the holding position of the solid device after punching and the position of the lead frame are automatically recognized, and relative positional deviations occurring therein can be corrected. The bonding position accuracy is high because the amount and direction are calculated and fed back to the movement control system of the XY direction moving table for solid device transfer for final positioning. In addition, by using transmitted light from below to recognize the holding position of the solid device, its shadow can be photographed and a uniform image can be obtained regardless of the situation when cutting the external lead, ensuring reliable work without automatic recognition errors. is possible.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of the external lead joining method according to the present invention, Fig. 2 is a right side view of Fig. 1, Fig. 3 is a plan view of Fig. 1, and Fig. 4 is a solid device. 5 is a partial detailed right side view of the transfer section of FIG. 4, FIG. 6 is an explanatory diagram of the operation of the optical position recognition means provided in the solid device transfer section, and FIG. 7 is a bonding Operating state diagram at time, No. 8
The figure is a plan view of the film carrier, Fig. 9 is a plan view of the lead frame, Fig. 10 is a plan view of the substrate, Fig. 11 is a plan view of the solid device bonded to the lead frame, and Fig. 12 is a plan view of the solid device bonded to the substrate. FIG. 3 is a top view and a side view of a solid state device. DESCRIPTION OF SYMBOLS 1... Film carrier, 2... Solid device, 2a... External lead, 3... Lead frame, 3a... Lead joint part, 30... Punch unit, 40... Transfer arm device, 43... X direction movement Table, 46...first Y direction moving table,
49... Second Y direction moving table, 55... Vacuum suction head, 60... Optical device, 61... Camera, 62... Prism, 63... Light projector.

Claims (1)

[Claims] 1 Punching a solid device supported by external leads on a film carrier,
In an external lead bonding method, the punched solid device is sucked by a vacuum suction head, transferred and placed on a lead joint portion on a lead frame, and the external lead and the lead joint portion are bonded. Light is projected onto the camera so as to pass through the held solid device from below, and the camera captures an image of the shadow of the external lead due to this transmission.This is processed by the recognition unit to determine the position relative to the position of the lead frame. An external lead bonding method characterized by calculating the deviation and feeding it back to a movement control system of an XY direction moving table for transferring the solid device to position the solid device at a predetermined position on the lead frame.