JPH08204084A - Lead frame for semiconductor integrated circuit device and manufacturing method thereof - Google Patents

Abstract

PURPOSE: To provide a surface of lead frame and its manufacturing method thereof which allows the size of a semiconductor integrated circuit chip mounting part of the lead frame to be changed freely and easily in accordance with the size of the chip mounted on devices of various sizes. CONSTITUTION: A lead frame has inner leads 9 and support leads 2 the inner top ends of which are all connected en bloc at a central part of the lead frame. In accordance with the size of various semiconductor integrated circuit chips, the position of an inner lead cut part 3 of the inner leads 9 is changed to thereby use the remaining inner top ends 1 remaining at the central part of the frame 5 and support leads 2 as a part for mounting the chip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame for a semiconductor integrated circuit device and a method for manufacturing the same, and more particularly to a lead frame for a semiconductor integrated circuit device on which various types of semiconductor integrated circuit device chips can be mounted and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a lead frame for a semiconductor integrated circuit device (hereinafter referred to as a lead frame), for example, a semiconductor integrated circuit on a lead frame is disclosed in JP-A-1-261851. Device (hereinafter,
This is to change the size of the chip mounting part (referred to as a semiconductor integrated circuit), and devised a mold when creating the lead frame by a press method to create islands of different sizes that do not themselves have front and back penetration patterns. There is a manufacturing method in which a lead frame is formed by punching and forming with an island manufacturing die of various sizes and then forming inner leads using a die having one size die and a punch of each mounting model size. It was

[0003]

SUMMARY OF THE INVENTION In this conventional technique,
Island punching die for island size and punch and inner lead punching punch for island size are required, and die is better than preparing die for die punching for each mounted model size and inner lead punching die for various island sizes. Although the number can be reduced, there is a problem that the size of the mounting part cannot be freely and easily changed according to the size of the semiconductor integrated circuit chip of each mounting model, resulting in enormous die cost. It was

Generally, a die is very important in matching a die and a punch, and two sets of die and punch each adjusted in detail based on the same drawing are used by changing the combination of the die. There are problems that biting occurs even when just hitting and the die and the punch do not move, and that the gap between the die and the punch is large and burr frequently occurs on the end surface of the pressed product.

An object of the present invention is to reduce the number of molds to reduce the cost of molds and burrs, and to freely and easily change the size of the mounting portion according to the semiconductor integrated circuit chip 1 of each mounting model size. An object is to provide a lead frame for an integrated circuit device and a method for manufacturing the same.

[0006]

A lead frame for a semiconductor integrated circuit device according to a first aspect of the present invention has a lead for a semiconductor integrated circuit device having an inner lead and a support lead whose tip portions in the inner direction are collectively connected at a central portion. In the frame, the cutting position of the inner lead is changed according to the size of the semiconductor integrated circuit device chip to be mounted, and the inner lead end portions of the inner lead and the support lead remaining in the center part of the semiconductor integrated circuit device chip are The feature is that it is a mounting part.

According to a second aspect of the present invention, there is provided a method of manufacturing a lead frame for a semiconductor integrated circuit device, wherein an inner lead and a support lead are integrally connected at a central portion of a tip portion in the inner direction, an outer lead connected to the inner lead, and A step of forming an unfinished lead frame having inner leads and a dam bar for supporting each of the outer leads, and pressing using an inner lead cutting die whose position is changed according to the size of the semiconductor integrated circuit device chip to be mounted or The method is characterized by including a step of cutting the inner lead by YAG laser processing using high-pressure air as an assist gas, and a step of performing pretreatment and performing partial silver plating.

According to a third aspect of the present invention, there is provided a method of manufacturing a lead frame for a semiconductor integrated circuit device, wherein an inner lead and a support lead are integrally connected at a central portion of a tip portion in an inner direction, an outer lead connected to the inner lead, and A step of forming an unfinished lead frame having an inner lead and a dam bar for supporting each of the outer leads; a step of performing a pretreatment on the unfinished lead frame and performing a partial silver plating; And a step of cutting the inner lead by press working using an inner lead cutting die by changing the position according to the size of the semiconductor integrated circuit device chip to be mounted.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a lead frame for a semiconductor integrated circuit device, which comprises a step of forming an auxiliary hole for pattern positioning in a copper strip for a lead frame and a silver plating positioning using the auxiliary hole. And a die for pressing are positioned to pretreat the entire area smaller than the size of the semiconductor integrated circuit device package to be mounted, and a partial silver plating is performed, and the copper strip for the lead frame that is partially silver plated is intermediate. It has a process of handling as an inventory, an inner lead and a support lead whose inner ends are collectively connected at a central portion, an outer lead connected to the inner lead, and a dam bar supporting each of the inner lead and the outer lead. Following the process of forming the unfinished lead frame, the position is changed according to the size of the semiconductor integrated circuit device chip to be mounted. Characterized by a step of cutting the inner leads by a press process using a inner lead cutting die.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a plan view of one piece of the lead frame according to the first embodiment of the present invention, and FIG. 2 is a plan view of an unfinished lead frame used for the lead frame of FIG. FIG.
As shown in FIG. 3, the lead frame for one piece according to the first embodiment of the present invention has the inner lead end portion 1 of the inner lead and the support lead 2 gathered together at the central portion and collectively connected, and the inner lead cutting portion 3 The semiconductor integrated circuit chip mounting portion 4 and the 2nd bonding position 6 for connecting the wiring from the semiconductor integrated circuit chip to the lead frame 5, the outer lead 7 and the dam bar 8 are provided to enhance the connectivity of the gold wire to the lead frame. The surface is plated with silver for the purpose.

A first method of manufacturing a lead frame according to the present invention.
In the embodiment, first, an unfinished lead having an inner lead 9, a support lead 2, an outer lead 7 and a dam bar 8 is first formed by pressing a lead frame punching die from a copper strip as shown in FIG. The frame 10 is formed. Subsequently, in the inner lead cutting step, the inner leads 9 of the unfinished lead frame 10 are cut off using the first inner lead cutting mold. The lead frame 5 shown in FIG. 1 is cut off. This lead frame 5
The inner lead 9 shown in FIG.
As described above, the semiconductor integrated circuit chip is mounted in the assembly area of the inner lead inner end portion 1 and the support lead 2 inside the inner lead cutting portion 3 as described above. Finally, silver plating was applied to the surface to improve the connectivity of the gold wire to the lead frame, and the lead frame 5 according to the first embodiment of the lead frame manufacturing method of the present invention shown in FIG. 1 was completed.

FIG. 3 is a plan view of one piece of the second embodiment of the lead frame of the present invention. The one-piece lead frame of the second embodiment of the present invention is the lead frame shown in FIG. 3 in which the inner lead 9 of the unfinished lead frame 10 of FIG. 2 is punched out by the second inner lead cutting mold. Eleven. The inner lead cutting section 12 of the lead frame 11 is located in the center of the inner lead cutting section 3 shown in FIG. 1, and therefore the lead frame 11 is smaller in size than the semiconductor integrated circuit chip mounted on the lead frame 5. The structure is suitable for mounting circuit chips.

FIG. 4 is a plan view of one piece of the third embodiment of the lead frame of the present invention. The lead frame for one piece of the third embodiment of the present invention is the lead frame shown in FIG. 4 in which the inner lead 9 of the unfinished lead frame 10 of FIG. 2 is punched out by the third inner lead cutting mold. It is 13. The inner lead cutting portion 14 of the lead frame 13 extends outside the inner lead cutting portion 3 shown in FIG. 1, and therefore the lead frame 13 has a size larger than that of the semiconductor integrated circuit chip mounted on the lead frame 5. The structure is suitable for mounting a semiconductor integrated circuit chip.

As described above, according to the present invention, the die for forming the inner lead and outer lead patterns having a more complicated shape than the die for punching the inner pattern of the die used in the press method is used. Both pads can be integrated into one, and it is enough to prepare various types of inner lead cut molds of relatively simple shape.

FIG. 5 is a flow chart for explaining the flow of the manufacturing process of the second embodiment of the method for manufacturing the lead frame of the present invention. Second method of manufacturing lead frame of the present invention
As shown in FIG. 5, first, the inner lead 9, the support lead 2, the outer lead 7, and the dam bar 8 are first formed from a copper strip by press using a lead frame punching die as shown in FIG. An unfinished lead frame having is formed (S1). Subsequently, in the cutting process of the inner lead, the high pressure air is used as an assist gas and the wavelength is 790 nm and the output is 7
A YAG laser having 0 W and a laser pulse width of 0.8 msec was used, and the measurement was performed while moving the lead frame at a focal length of 100 mm and a speed of 0.3 m / min. In the case of a copper material having a plate thickness of 0.15 mm, although the generation of dross in which the molten copper material was fixed near the cut surface was observed, the inner lead could be cut with a width of 0.2 mm. Since the equipment used in the second embodiment of the lead frame manufacturing method moves the table on which the lead frame is placed by computer control, the movement pattern of the lead frame can be freely changed by changing the input data to the computer. I was able to change.
For this reason, the three types of semiconductor integrated circuit chip mounting sizes implemented in the first, second, and third embodiments of the lead frame are
It was possible to easily realize without making the inner lead cutting die each (S2). The dross generated by laser cutting could be completely removed by immersing the etching of the pretreatment for plating in a hydrochloric acid solution when the sample of this example was put into the lead frame surface treatment step by the silver plating method. Thereafter, the surface of the lead frame was partially silver-plated (S3), and the lead frame according to the second embodiment of the method for manufacturing a lead frame of the present invention was completed (S4).

FIG. 6 is a flow chart for explaining the flow of the manufacturing process of the third embodiment of the lead frame manufacturing method of the present invention.

In the first embodiment, after the lead frame pattern was formed by the press method, silver plating was applied to the surface of the lead frame to enhance the connectivity of the gold wire to the lead frame. Because of the structure, there is a problem that the 2nd bonding position 6 of the inner lead 9 is deformed. Further, if the lead frame is formed after the size of the semiconductor integrated circuit chip is clarified, there is a problem that it is very difficult to adapt to a semiconductor integrated circuit that requires a short delivery period. Therefore, in the third embodiment of the method for manufacturing a lead frame of the present invention, an attempt was made to carry out the manufacturing method in which the inner lead cutting operation, which cannot be done unless it is clear, was brought to the final step. As shown in FIG. 6, first, similarly to the first embodiment, the inner lead 9 and the support lead 2 are pressed from a copper strip by press working using a lead frame punching die as shown in FIG.
Then, the unfinished lead frame 10 having the outer leads 7 and the dam bars 8 is formed (S1). In the state of the unfinished lead frame 10, a plating mask having a size 0.2 mm smaller on one side than the outer size of the semiconductor integrated circuit package is formed, and this plating mask is used to place the plating mask at a predetermined position in the central portion of the unfinished lead frame 10. The step (S2) of performing partial silver plating is inserted. In this embodiment, since the lead frame is unfinished, both ends of the inner lead 9 are connected to other patterns, so that the inner lead 9 generated when the cantilevered inner lead 9 is plated. No deformation occurred at all. Also,
Since the unfinished lead frame 10 after plating can be handled as an intermediate stock (S3), when the unfinished lead frame 10 is manufactured up to this step in advance and the semiconductor integrated circuit chip to be mounted is decided, the intermediate stock product is obtained. It was possible to shorten the lead-frame acquisition time by sending to the subsequent process based on the mounted semiconductor integrated circuit chip size information. However, when the unfinished lead frame 10 is to be cut by the laser used in the second embodiment of the lead frame manufacturing method, the inner lead cutting dross is deposited on the silver plating applied to the surface, and the lead frame is formed as a lead frame. Since it cannot be used anymore, in this embodiment, the lead frame could be formed only by fixing the inner lead cutting method by a die. Therefore, the inner lead cutting is performed by cutting the mold (S4), and the lead frame according to the third embodiment of the lead frame of the present invention is completed (S5).

FIG. 7 is a flow chart for explaining the manufacturing process flow of the fourth embodiment of the lead frame manufacturing method of the present invention. The plating process is sandwiched between the pressing processes, and when trying to produce a lead frame straight without entering the intermediate inventory, it takes time to move between processes and it takes time to complete the lead frame. was there. The fourth embodiment of the method for manufacturing a lead frame of the present invention was carried out to solve the problem.

Fourth method of manufacturing lead frame of the present invention
In the third embodiment, in order to assist the pattern positioning in the pressing process in advance, an auxiliary hole with a precision that can be opened in the plating process is formed on the copper strip for the lead frame, and is used in the third embodiment of the lead frame manufacturing method. The existing plating mask is diverted, and silver plating is finally applied to the position included in the semiconductor integrated circuit package, and the intermediate stock is to be prepared in this state. In the present embodiment, as shown in FIG. 7, first, the above-mentioned auxiliary holes are used to perform the positioning of the silver plating and the positioning of the pressing die, and then they are contained inside the semiconductor integrated circuit package. Partial silver plating is applied to the position (S1) and the intermediate stock is placed in this state (S2). Next, according to the mounted semiconductor integrated circuit chip size information, press working is performed using a lead frame punching die, as shown in FIG.
As shown in FIGS. 3 and 4, the inner lead 9, the support lead 2, the outer lead 7, and the dam bar 8 are formed, and then the inner lead is cut at the position of the inner lead cutting portion 3 (S3), and the lead frame of the present invention is obtained. A lead frame according to the fourth embodiment of the manufacturing method of is completed (S4). In this case, unlike the third embodiment, the lead frame can be manufactured by only moving once between the steps, and all the operations can be performed even once in the pressing step, so that the work efficiency can be improved. It was

[0021]

As described above, according to the present invention, an unfinished lead frame in which the inner ends of all the inner leads and the support leads are connected together at the central portion of the lead frame in advance is used to produce various semiconductor integrated circuit chips. By changing the position where the inner lead is cut off in accordance with the size of the inner lead and using the inner leading end portion of the inner lead and the support lead portion remaining in the central portion as the mounting portion of the semiconductor integrated circuit chip, a relatively complicated shape is formed. Various types of lead frame punching dies can be integrated into one, and by arranging the dies for cutting the inner leads of relatively simple shape according to the size of various semiconductor integrated circuit chips, it is possible to easily It has an effect that lead frames of various island sizes can be obtained.

On the other hand, when the inner lead cutting of the unfinished lead frame is performed by the laser, there is also an effect that the lead frame corresponding to various semiconductor integrated circuit chip sizes can be formed with only one die.

By placing the inner lead cutting process at the final stage of the lead frame manufacturing process,
There is also an advantage that mass production of unfinished leadframes of the same pattern and quick acquisition of leadframes after the model determination of mounted semiconductor integrated circuit chips can be achieved.

[Brief description of drawings]

FIG. 1 is a plan view of one piece of a first embodiment of a lead frame of the present invention.

FIG. 2 is a plan view of an unfinished lead frame used in the lead frame of FIG.

FIG. 3 is a plan view of one piece of the second embodiment of the lead frame of the present invention.

FIG. 4 is a plan view of one piece of the third embodiment of the lead frame of the present invention.

FIG. 5 is a flowchart illustrating a flow of manufacturing steps of a second embodiment of the lead frame manufacturing method of the present invention.

FIG. 6 is a flow chart illustrating a flow of manufacturing steps of a third embodiment of the lead frame manufacturing method of the present invention.

FIG. 7 is a flowchart illustrating a flow of manufacturing steps of a fourth embodiment of the lead frame manufacturing method of the present invention.

[Explanation of symbols]

 1 Inner lead end part in the inner direction 2 Support lead 3,12,14 Inner lead cutting part 4 Semiconductor integrated circuit chip mounting part 5,11,13 Lead frame 6 2nd bonding position 7 Outer lead 8 Dam bar 9 Inner lead 10 Unfinished lead frame

Claims (6)

[Claims] 1. A lead frame for a semiconductor integrated circuit device having an inner lead and a support lead, the inner ends of which are integrally connected at a central portion, wherein the inner lead is matched to the size of the semiconductor integrated circuit device chip to be mounted. 2. A lead frame for a semiconductor integrated circuit device, characterized in that the cutting positions are changed and the inner leading ends of the inner leads and the support leads remaining in the central part are mounted parts of the semiconductor integrated circuit device chip. 2. An inner lead and a support lead whose inner ends are collectively connected at a central portion, an outer lead connected to the inner lead, and a dam bar for supporting each of the inner lead and the outer lead. A step of forming a completed lead frame, a step of changing the position according to the size of a semiconductor integrated circuit device chip to be mounted and cutting the inner lead, and a step of performing pretreatment and performing partial silver plating, Method for manufacturing lead frame for semiconductor integrated circuit device. 3. The method for manufacturing a lead frame for a semiconductor integrated circuit device according to claim 2, wherein the step of cutting the inner leads includes a pressing step using an inner lead cutting die. 4. The method for manufacturing a lead frame for a semiconductor integrated circuit device according to claim 2, wherein the step of cutting the inner lead includes a YAG laser processing step using high pressure air as an assist gas. 5. An inner lead and a support lead, which are integrally connected at a central portion of a tip portion in the inward direction, an outer lead connected to the inner lead, and a dam bar supporting each of the inner lead and the outer lead. Depending on the size of the semiconductor integrated circuit device chip to be mounted, the process of forming the completed lead frame, the process of pre-processing the unfinished lead frame and partial silver plating, the process of treating this unfinished lead frame as an intermediate stock And a step of cutting the inner lead by press working using an inner lead cutting die, the positions of which are also changed, and the method of manufacturing a lead frame for a semiconductor integrated circuit device. 6. A semiconductor integrated circuit to be mounted by performing a step of forming a pattern positioning auxiliary hole in a copper strip for a lead frame, and positioning the silver plating and the pressing die by using the auxiliary hole. A step of performing pretreatment on a whole area smaller than the size of the device package and performing partial silver plating,
The step of treating the partially-plated copper strip for lead frame as an intermediate stock, the inner lead and the support lead whose inner end portions are collectively connected at the central portion, the outer lead connected to the inner lead, and the inner lead. Following the step of forming an unfinished lead frame having leads and dam bars for supporting each of the outer leads, the position of the inner lead is changed according to the size of the semiconductor integrated circuit device chip to be mounted, and the inner lead is cut using an inner lead cutting mold. And a step of cutting by a press process as described above, the method for manufacturing a lead frame for a semiconductor integrated circuit device.