JPH0682771B2 - Chip carrier manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a semiconductor integrated circuit device (IC), and in particular, in a chip carrier made of plastic or the like, a tip of a lead terminal led out from a side surface of a package body is provided. The present invention relates to a method of molding so as to face the bottom surface of a package body.

A perspective view of such an IC is shown in FIGS. 1 (a) and 1 (b).
The package body 11 made of plastic etc. has a top surface 1, a bottom surface 2 and side surfaces
It has 3,4,5,6. In the example of FIG. 1A, five leads 14 are led out from the side surfaces 3 and 5, respectively, and four leads 14 are led out from the side surfaces 4 and 6, respectively, to make an IC with a total of 18 pins. Further, by deriving the leads from the four side surfaces in this way, a 68-pin (the number of leads is 68) or 84-pin (the number of leads is 84) IC can be made. On the other hand, in the example shown in FIG.
The lead 14 of the book is led out, but the lead is not led out from the short side surfaces 4 and 6, and the total of 20 leads of 20 pins
It is an IC.

In either case of FIGS. 1 (a) and 1 (b), the lead 14 is bent so that the lead 14 extends downward from the side surface, then faces downward, the bottom surface downward, and the tip end faces the bottom surface. ing.

[Conventional technology]

Conventionally, in order to form this lead into such a shape, after cutting the lead to a specified length, the center part except for the part adjacent to the tip is bent linearly at 45 ° with an upper die punch and a lower die. Then, the lead was bent in the vertical direction, and finally the lower die having a semicircular groove was pushed down by the upper die punch to form the semicircular curling diode.

[Problems to be Solved by the Invention]

Since such a molding method depends only on the vertical force of the die or punch, it has a defect that the plating on the lead surface is scraped. Furthermore, when this occurs in the final curling process, the scraps of the scraped plating and the separated resin burrs fall, and there is a semicircular curling die that matches the shape of the final molding lead as it is. However, the scraps of the plating and the separated resin burr cannot be escaped to the outside of the apparatus, and gradually accumulate in the groove of the semicircular curling die. As a result, when molding the leads of ICs that are set one after another, these scraps and burrs are driven into the surface, resulting in defects. For example, if plating is undesirably attached to the leads, a short circuit occurs between the leads of the plastic carrier and it becomes defective, and if resin burrs are driven into the lead surface, the plastic chip carrier is soldered to the printed circuit board. At that time, the solder repels and becomes defective.

[Means for Solving the Problems]

The method of manufacturing a chip carrier of the present invention is a method of manufacturing a chip carrier, which comprises a step of molding the tips of the leads of the IC led out from the side surface of the package body so as to face the bottom surface of the package. A first step of cutting, a second step of lifting the lead in an obliquely upward direction and then vertically descending a roller to form an arc-shaped portion adjacent to the tip of the lead, while sandwiching the root of the lead A third step of pushing down the lead, a fourth step of bending the lead downward with a vertically descending roller, and a roller arranged in the downward direction, the lead being used to move the lead to the tip of the package body. And a fifth step of processing so as to face away.

In the second step, the reed can be lifted up to 20 ° to 60 ° above the horizontal. Then, a force is applied in the vertical direction to the portion adjacent to the tip of the lead by a freely rotatable roller. If the angle of inclination is 45 ° and it is bent by a roller, the lead will have some return, but this tip part will be shaped to an arc shape of about 3/8 circle. By providing an arc at the tip in advance, the burden of molding afterwards can be reduced, and since the roller that can rotate freely is used, the lead surface plating is almost never scraped. it can. The pressing in the third step is 20 ° from the horizontal direction
It is preferable to point downward by 50 °. If it is larger than 50 °, the conventional defect, that is, there is a risk of separation of the plating on the lead surface, and if it is smaller than 20 °, the burden of bending the lead in the vertical direction by the roller in the fourth step is large. Become. Since the rollers in the fourth step and the fifth step are also rotatable, the plating on the lead surface is hardly separated. The roller in the fifth step is preferably arranged in the vacuum suction port. As a result, the separated resin burr in the same process or the scraps of plating or other foreign substances in the same process which may be generated a little can be efficiently discharged out of the apparatus by the suction force of the vacuum and the rotation of the roller. In the fifth step, molding can be performed by the action of a curling die having a circular arc groove whose cross-sectional shape conforms to the shape of the final lead and a roller and a roller. Alternatively, it is possible to perform molding by the action of two rollers by using a curling die having an arc whose cross-sectional shape is much smaller than the arc having a quarter circle. In any case, the above effect is obtained because the curling die having a circular arc of 1/2 is not used and the roller is used instead.

Note that, in the present specification, the vertical, horizontal, etc. directions have been described assuming that the package body is held horizontally. However, when the package is held vertically, this should be read as horizontal, vertical, etc., respectively.

〔Example〕

 The present invention will be described in detail below with reference to the drawings.

2 (a) to 2 (e) are schematic cross-sectional views of the functional parts of the respective devices of the plastic carrier lead forming method according to an embodiment of the present invention.

Note that the devices shown in FIGS. 2 (a) to 2 (e) are provided independently of each other, and ICs for molding leads between them are sequentially sent to each device one after another. The work of the process is performed, and the work of FIG. 2 (e) is completed. From the device shown in FIG. 2 (e), the IC (for example, the one shown in FIG. 1 (b)) for which the predetermined lead forming is completed is taken out. Further, in each drawing, the IC package body 11 is mounted so that the top surface 1 and the bottom surface 2 thereof are horizontal, and the leads in FIG. 1A are drawn out in the horizontal direction. Further, in order to avoid complication, the cross section of the package body itself is not shown (illustration of the internal IC chip is omitted).

The first step is performed by the device shown in FIG. Here, a pad 13 and a die 12 are provided above and below a plastic carrier (resin package body) 11, and leads extending in the horizontal direction are sandwiched and fixed by the pad 13 and the die 12 so that the lead 14 has a predetermined length. The tip is cut by a cutting punch 15 which vertically descends along an arrow 40.

Next, the second step is performed by the device shown in FIG. 2 (b). Here, the lower surface of the root 44 of the lead 14 is greeted by the die 17, and the other part of the lead 14 is applied with force upward as shown by an arrow 41 by the lead forming die 18 inclined obliquely upward. . On the other hand, the upper surface of the lead is greeted by an obliquely upper punch 16 whose base 44 is horizontally inclined and the other is inclined obliquely upward, and in this state, the tip of the lead 14 is formed into an arc shape. These operations are performed as follows. That is, a freely rotatable tip bending roller 19 which vertically descends together with the diagonally upper punch 16 as shown by an arrow 42 is provided, and the diagonally upper punch 16 descends and leads between the die 17 and the lead.
The punch 16 descends by sandwiching 14 and the die 17 sinks, leaving the lead forming die 18 and processing the lead 14 diagonally upward. After that, the tip bending roller 19 descends and the lead
14 form an arc shape at the tip. Roller 19 lead 14
It comes into contact with and thereby rotates with its axis.

Next, the third step is performed by the apparatus shown in FIG. 2 (c). In the oblique bending process, the roots 44 of the leads 14 are sandwiched by the pads 22 on the oblique bending die 21 fixed, and the leads are formed obliquely downward by the oblique bending punch 24 that vertically descends as shown by the arrow 43.

Next, the fourth step is performed by the device shown in FIG. In this vertical bending process, the bottom surface 2 of the plastic carrier 11 abuts the receiving die 25, while the lead
The upper surface of the base 44 of 14 is greeted by the pad 26 and is sandwiched so that it is free to rotate and moves downward as indicated by arrow 46.
Then, the lead 14 is pushed down vertically. Similarly to the roller 19, the roller 27 also contacts with the lead 14 to rotate with its axis.

Then, the fifth fixing, which is the final step shown in FIG. 2 (e), is performed. In this final curling step, a groove 29 having a cross-sectional shape of about 1/4 circular arc (90 ° circular arc) is provided on the upper side surface of the curling die 28. The side of the lead 14 which is vertical is pressed by the side die 48, and the inside of the side die 48 is a rotatable roller.
An arcuate cut 49 is provided so that 31 can be easily placed. The curling die 28 and the side die 48 can be constructed as one body, but in any case, a vacuum chamber is formed between them and the roller 31 is provided at the opening 30 of the vacuum chamber. In the plastic carrier (plastic package body) 11, the curling punch 32 abuts on the upper surface 1 and the root 44 of the lead 14 and is moved downward as indicated by an arrow 47 to be pushed down, and the curling punch 32 is rotated by the second roller 31 to be freely rotated. In the process, the lead 14 whose tip portion is formed in an arc shape comes into contact with the rotation of the roller 31 and the lead 14 is gradually bent toward the inside in an arc shape, and the tip 50 of the lead is packaged along the groove 29. 11 The back surface 2 is curled around and the tips 50 of the leads 14 face the bottom surface 2 of the package body 11. At this time, each roller 31 rotates in the direction of arrow 51. At this time, since the tip of the lead is previously formed with an arc of, for example, about 3/8 in the second step, the above-mentioned work can be performed. If an arc is not formed in advance at the tip, the tip of the lead will not be curled by the roller at the opening 30 and will collide with the member at this opening. Further, the resin burr that drops during curling in this step is discharged from the suction port 30 by the suction force and the rotation of the roller, and is not driven into the lead.

FIG. 3 is a schematic sectional view of a functional portion of a lead molding device for a plastic chip carrier according to another embodiment of the present invention. The steps of FIGS. 3A to 3D are shown in FIGS.
Since they are the same corresponding to (d), they are the same drawings. Therefore, the description of the first to fourth steps of this embodiment will be omitted. In FIG. 3 (e) showing the fifth step, the same functions as those in FIG. 2 (e) are designated by the same reference numerals. In the fifth step of FIG. 3 (e) of this embodiment, one lead 14 is paired with a pair of two rollers 131, 132.
They are arranged side by side on the left and right and rotate freely in the direction of arrow 51 for curling. This roller 131,13
2 is provided in the opening 130 of the vacuum chamber which is wider than in the previous embodiment, and the scraps of the plating and the resin burrs that have separated during the process are eliminated from here. Also, curling die 12
At the upper end of 8, the groove 29 of the curling die 28 of the previous embodiment.
Is provided with a guide notch groove 135. However, this results in very little contact with the leads. That is, in this embodiment, the curl itself is performed by two rollers, and the groove 135 is mainly intended to guide the curled lead to a predetermined portion. In this embodiment, since there is little friction between the curling die and the leads, there is an advantage that less plating adheres to the mold. Incidentally, rollers 31, 131, 132
By contacting the lead 14, it rotates with its axis.

In the case where the leads are led out from the four side surfaces as shown in FIG. 1 (a), the first step (FIG. 2 (a), FIG. 3 (a)) to the third step (FIG. 2 ( Up to c) and FIG. 3C, it is efficient to work simultaneously on all the leads 14 derived from the four side surfaces 3, 4, 5, 6 in each process. Fourth step (Fig. 2 (d), Fig. 3 (d))
It is more reliable to perform molding of the lead 14 led out from the opposite side surfaces 3 and 5 and molding of the lead 14 led out from the opposite side surfaces 4 and 6 separately. Further, in the process of FIG. 5 (FIGS. 2 (e) and 3 (e)), in the case of 18 pins, the leads 14 are simultaneously formed by leading out from the four side faces 3, 4, 5, 6. In the case of 68 pins and 84 pins, as in the fourth step, the molding of the leads 14 led out from the opposite side faces 3, 5 and the molding of the leads 14 led out from the opposite side faces 4, 6 are performed separately. Is practical considering both efficiency and reliability.

〔The invention's effect〕

As described above, by using the method for processing the leads of the plastic chip carrier according to the present invention, it is possible to reduce the plating adhesion to the mold, and according to the conventional method, the mold is cleaned once every 2,000 pieces. However, according to the method of the present invention, the frequency could be reduced to once every 50,000. In addition, the unwanted adhesion of the plating to the leads is eliminated, so that no short circuit occurs between the leads. Further, although 50% or more of the resin burrs were driven into the leads according to the conventional method, it is 0 according to the present invention.
It was possible to make it to%. This repels solder when soldering to the printed circuit board (solder does not adhere to the leads)
Does not occur. Moreover, the resin deburring work is no longer necessary.
Therefore, according to the present invention, it is possible to improve the operation rate of equipment and reduce the adhesion of burrs to products. The present invention exerts a great effect on the improvement of automation, the quality of products, and the cost reduction of products. You can

[Brief description of drawings]

FIG. 1 is a perspective view of an IC targeted by the present invention. 2 (a) to 2 (e) are schematic sectional views of a lead molding apparatus for a plastic chip carrier, which is an embodiment of the present invention.
3 (a) to 3 (e) show another embodiment of the present invention. 11 …… Package body (plastic chip carrier), 12,17 …… Die, 13,22,26,32 …… Pad, 14 ……
Reed, 15 ... Cutting punch, 16 ... Diagonal upper punch, 18
...... Lead forming die, 19,27,31,131,132 …… Roller,
21 …… Diagonal bending die, 24 …… Diagonal bending punch, 25 …… Receiving die, 28,128 …… Curling die, 29,135 …… Curling die upper side groove, 30 …… Suction port, 1 …… Package body top surface 2 ... Bottom of package body, 3,4,5,6
...... Side of package body, 44 ...... Root of lead 14 near package body, 50 ...... Lead 14 tip.

Claims (1)

[Claims] 1. A method of manufacturing a chip carrier, comprising a step of molding the ends of IC leads extending from the side surface of a package body so as to face the bottom surface of the package, and cutting the leads to a predetermined length. A second step of processing the portion adjacent to the tip of the lead into an arc shape by a roller that vertically lifts the lead and then vertically descends; and pressing down the lead while sandwiching the root of the lead. 3 step, 4th step of bending the lead downward with a vertically descending roller, and arranging the roller downward, and using the roller, the lead is processed so that its tip faces the package body. A method of manufacturing a chip carrier, comprising: a fifth step.