JPH03268456A - Manufacture of resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To ensure an accurate and stable cutting processing without use of a cutting punch by positioning a lead frame and cutting and removing dam part resin and a tie bar by laser beam irradiation, and thereafter moving the lead frame by one lead pitch for repetition of the same process. CONSTITUTION:A lead frame 6 is supplied onto a cutting stage 9, and positioned and fixed on the stage 9 using a positioning hole 7. Then, a CCD camera 4 picks up the lead frame as an image, and a portion of the lead frame to be cut first is aligned to a laser beam irradiation position based upon a calculation result by an image processing device 5, and dam part resin 10 and a tie bar part 11 are irradiated with the laser beam for cutting in a predetermined amount. After the lead frame is cut at the one portion of the same, the cutting stage is driven by a one lead pitch fraction by an X-Y table 8 based upon the previous calculation result, and the previous process is repeated using the laser beam. Hereby, there are eliminated the need of a cutting punch and the cutting by a die, and the present method can deal with cutting of lead frames of fine pitches and ensure stable processing accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a resin-sealed semiconductor device, and more particularly to a method for cutting a dam portion resin and a diver portion of a lead frame of a resin-sealed semiconductor device. .

[Prior Art] This type of resin-sealed semiconductor device (hereinafter referred to as IC) mounts a semiconductor chip on a lead frame, performs wire bonding, and then attaches the semiconductor chip and internal leads using a transfer method or the like. Manufactured by resin sealing.

During resin sealing, when the cavity in the sealing mold is filled with resin, a gap equal to the thickness of the lead frame is created at the punched part of the lead frame clamped by the mold, and the resin flows out from there. As shown in the partial perspective view of Fig. 3,
A dam portion surrounded by an IC package 13, adjacent external leads 12, and a diver portion 11 connecting the external leads is filled with a dam portion resin 10. Therefore, when lowering the cutting punch 14 in the direction of the arrow to cut and remove the diver part 11 in the next process, the resin 1 filled in the dam part
0 is also removed at the same time. In FIG. 3, the position and shape of the cut/remove portion 19 by the cutting punch 14 is indicated by a two-dot chain line.

Conventionally, the pitch between leads was 0.5 to 1. When cutting the dam part resin and diver part of the IC in the case of Ou+, the lead frame is placed on the die 15 that receives the lower surface of the external lead 12, as shown in FIG. 6 and lowered the comb-like cutting punch 14 into the dam part resin 10 and the diver part 11, and punched out every other pitch between the leads in two steps.

[Problem to be solved by the invention] In recent years, the demand for high-density packaging of ICs has led to a trend towards more bins and miniaturization, and as a result, the pitch between external leads has become finer, with a pitch of 0.511 m or less. The number of ICs that have been developed is increasing.

In the conventional cutting method using a cutting punch, when the pitch between leads is 0.5-1 and the lead terminal width is 0.211 m, there may be looseness during positioning of the lead frame and proper clearance between the cutting punch and die. Considering this, the thickness of the cutting edge of the cutting punch can only be about 0.2 fins, and there is a drawback that the cutting edge easily breaks if a load is applied due to clogging during cutting.

In addition, in the conventional method, it is difficult and expensive to integrate cutting punches and dies for forming comb blades when fine pitches are formed, so it is divided into 2 to 3 steps to process 1 pitch or 2 punches. Although a method of cutting at every pitch is used, due to looseness during positioning of the lead frame at each stage, misalignment of the tie bar section 16 as shown in the partial plan view of Fig. 5 is likely to occur, and the external lead Due to the punch biting into 12, deviations from standard dimensions and variations in lead dimensions tended to occur.

In addition, comb-shaped cutting punches are difficult to process and are therefore expensive, and if even one cutting edge breaks, it is necessary to replace the punch with a new one, so if the plate becomes thinner, the punch will break. Running costs are extremely high due to the high frequency. Therefore, as shown in the perspective view of FIG. 6, a cutting punch consisting of a combination of an individual piece cutting punch 17 and a spacer 18 is often used. The cumulative error in the thickness of the punch and spacer becomes large, and as a result, the cutting dimensional accuracy is inferior to that of the integrated method. Furthermore, in this method, as the pitch becomes finer, it becomes difficult to keep the clearance between the punch and the die within a predetermined range, leading to an increase in punch breakage.

Therefore, no matter which type of punch is used for cutting with a cutting punch or die, it is no longer possible to support finer pitches, and cutting punches with a thickness of 0.2u+ or less have no strength. There is also the problem of not being able to withstand it.

[Means for Solving the Problems] A method for manufacturing a semiconductor device according to the present invention includes: (1) positioning and placing a resin-sealed semiconductor device on an X-Y table;
The laser beam is irradiated while scanning parallel to the external leads to cut and remove the resin in the diver and dam parts of the lead frame one by one, and the x-y table is operated to attach the resin-sealed semiconductor device to the external leads. Feed by 1 lead pitch of
■Repeat the steps ■ and ■ the required number of times.

The pitch at which the lead frame of a semiconductor device is conveyed is determined based on, for example, the results obtained by image processing of image data captured by a CCD camera.

[Embodiments] Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram showing a cutting method according to an embodiment of the present invention. In the figure, 1 is a laser light source, 2a is a reflecting mirror, 2b is a half mirror, 13 is a galvanometer mirror for scanning the laser beam, 4 is a CCD camera, and 5 is a CCD
An image processing device that processes images obtained from a camera, 6 a lead frame on which a plurality of resin-sealed semiconductor chips are mounted, 7 a positioning hole drilled in the lead frame, 8 an x-y A table 9 is a cutting stage placed on an XY table for accommodating a lead frame.

Next, a cutting method using this device will be explained. First, the lead frame 6 is supplied onto the cutting stage 9,
The lead frame 6 is positioned and fixed on the stage by a positioning bin provided on the stage 9 using a positioning hole 7 formed in the lead frame 6 . Next, the CCD camera 4 captures an image of the lead frame through the half mirror 2a,
The image information is sent to the image processing device 5. Image processing device 5
Now, the absolute position of each external lead of the lead frame is recognized, and the positions of the dam part resin and diver part to be cut are determined by calculation processing. Based on the calculation result, the X-Y table is operated as necessary to align the part of the lead frame 6 to be cut first with the laser beam irradiation position. After that, the laser beam from the laser light source 1 is transferred to the mirror 2a.
, 2b, irradiate onto the dam part resin and diver part to be cut through the galvanometer mirror 3. At this time, by driving the galvanometer mirror 3, the laser beam is continuously irradiated while scanning in a direction parallel to the external lead to cut a predetermined amount. After cutting one location is completed, the cutting stage is driven by one lead pitch to the adjacent dam resin and diver portion to be cut using the X-Y table 8 based on the previous calculation result, and then Cutting is performed using a laser beam in the same manner as in the step. Thereafter, the same conveying process and cutting process are repeated.

Ic, when the cutting of the pieces is completed, the lead frame 6
Ic is transported individually, and then cutting is performed as described above. When the cutting of one lead frame is completed, the lead frame is removed by a transport mechanism (not shown), and a new uncut lead frame is transported. It will be done.

As explained above, the present invention does not use a cutting punch that is damaged during cutting, so running costs can be reduced. In addition, the laser beam
Since it is possible to reduce the beam diameter to 0.2+u+ or less, according to the manufacturing method of the present invention, the pitch between the leads can be reduced to 0.
．． It can also be easily applied to fine pitch ICs of 5+n or less. Further, in this embodiment, the cutting position is calculated by image recognition of each external lead one by one, and positioning is performed based on the result, so that positional deviation during cutting is eliminated and processing accuracy can be stabilized. Furthermore, conventionally it was necessary to prepare a different mold for each product type, but with the method of this embodiment, the cutting position is determined while recognizing each external lead, so the cutting position can be automatically determined by registering the product type data. Moreover, it can be easily applied to a wide variety of products.

FIG. 2 is a configuration diagram showing a cutting method according to a second embodiment of the present invention. In FIG. 2, parts that are equivalent to those of the previous embodiment shown in FIG. 1 are given the same reference numerals.

In this embodiment, the CCD camera 4 captures an image of a range of Ic on the lead frame 6, and the positioning hole 7 and a plurality of points on the lead frame 6 are image-recognized.
The position of the point to be cut is determined based on the result and lead frame information unique to the model inputted in advance.

From this point on, as in the previous embodiment, the operation of driving the X-Y table to position the lead frame, scanning the laser beam parallel to the external lead, and cutting the dam part resin and diver part is repeated.

In the case of this embodiment, although it is necessary to input data regarding the cutting position for each type into the program in advance, the positions of all external leads for each type are not determined by image processing. The time required for this can be reduced. Therefore, according to this embodiment, it is possible to efficiently and accurately cut a product with little variation in external lead position accuracy due to shrinkage of the lead frame after resin sealing or the like.

In this embodiment, image processing can be performed more efficiently by attaching positioning marks to appropriate locations on the lead frame.

Note that in the above embodiments, the position of the external lead was determined by optical means to position the lead at the time of cutting. However, if sufficient accuracy can be obtained by mechanical positioning means, optical It is not necessary to use an optical position detection means, and even if an optical position detection means is used, it is not necessary to do this for all ICs.If there is little variation within the same lot, the first number Optical position detection may be performed for each IC in the lot, and positioning may be performed using the obtained results for other ICs in the lot.

[Effects of the Invention] As explained above, the present invention positions a lead frame on an X-Y table, irradiates a laser beam to cut and remove the dam part resin and tie bars of the lead frame, and then removes the lead frame. Since the sheet is transported by one lead pitch and the same process is repeated, the following effects can be achieved.

■ Since no cutting punch is used, there is no chance of punch damage and running costs can be reduced.

■ Pitch deviations do not occur as would occur when two-step punching is performed using a cutting punch.

■ Accurate cutting is possible by using optical position detection means depending on the pitch and diameter, so fine pitch I
Accurate and stable cutting is also possible for C.

■ Product changes can be made immediately by changing the program, etc., making it easier to handle high-mix, low-volume production of products.

12...External lead, 14... Cutting punch, Misalignment of the diver section, 18...Spacer 3...IC package, 5...Die, 16... 7... Piece cutting punch, 9... Cutting removal section.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the cutting method according to the first embodiment of the present invention, FIG. 2 is a block diagram showing the cutting method according to the second embodiment of the present invention, and FIG. 3 is a block diagram showing the cutting method according to the second embodiment of the present invention. A partial perspective view showing the method;
FIG. 4 is a cross-sectional view taken along line A-A in FIG. 3, and FIG.
FIG. 6, a partial plan view showing the cutting deviation of the diver section according to the conventional cutting method, is a perspective view of a combination cutting punch used in the conventional cutting method. DESCRIPTION OF SYMBOLS 1... Laser light source, 2b... Half mirror 4... CCD camera, 6... Lead frame, 8... X-Y table, 10... Dam part resin, 2a... Reflection mirror 3... Galvano mirror 5... Image processing device, 7... Positioning hole, 9... Cutting stage, 11... Diver section,

Claims (5)

[Claims] (1) a. Positioning and placing the resin-sealed semiconductor device on an X-Y table; b. Irradiating the dam part resin and cutting and removing the diver portions of the lead frame one by one; c. operating the X-Y table to transport the semiconductor device by one lead pitch of the lead frame programmed in advance; d. A method for manufacturing a resin-sealed semiconductor device, comprising the steps of alternately repeating steps b and c. (2) a. Placing the resin-sealed semiconductor device on an X-Y table; and b. Recognize the position of the resin-sealed semiconductor device using an imaging device and place the semiconductor device on a laser beam emitted by a laser light source. positioning with respect to the beam; c. cutting and removing the dam resin and the diver portion of the lead frame one by one by irradiating the outer lead of the lead frame with the laser beam while scanning in parallel; d. A resin seal comprising: operating the X-Y table to transport the semiconductor device by one lead pitch of the lead frame programmed in advance; e, repeating steps c and d alternately; A method for manufacturing a static semiconductor device. (3) a. Placing the resin-sealed semiconductor device on an X-Y table; and b. Recognizing the positions of the plurality of leads of the lead frame of the resin-sealed semiconductor device using an imaging device and placing the semiconductor device on the X-Y table. positioning the device with respect to the laser beam emitted by the laser light source; c. irradiating the external leads of the lead frame while scanning them in parallel to cut and remove the dam part resin and the diver part of the lead frame one by one. d, based on the recognition of the lead position in step b,
- A method for manufacturing a resin-sealed semiconductor device, comprising: operating a Y table to transport the semiconductor device by one lead pitch of the lead frame; e. repeating steps c and d alternately; . (4) The step of positioning and placing the resin-sealed semiconductor device on an A resin-sealed semiconductor device comprising the steps of: cutting and removing the parts one by one; and transporting the semiconductor device by one lead pitch of the lead frame programmed in advance by operating the X-Y table. In the manufacturing method, the placement position of the resin-sealed semiconductor device on the X-Y table is determined based on results obtained by image processing image data for other semiconductor devices in the same lot. 1. A method of manufacturing a resin-sealed semiconductor device, characterized in that: (5) A step of scanning the laser beam parallel to the external leads of the lead frame to cut and remove the dam part resin and the diver part of the lead frame one by one, and a step of transporting the resin-sealed semiconductor device a predetermined distance. In the method for manufacturing a resin-sealed semiconductor device in which steps 1 and 2 are alternately repeated, the predetermined distance is an interval between external leads obtained by image processing image data of other semiconductor devices in the same lot. A method for manufacturing a resin-sealed semiconductor device.