JP3178132B2 - Manufacturing method of LOC semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a LOC type semiconductor device, and more particularly to a novel LOC which can eliminate the risk of deformation of leads, does not require complicated tape processing, and can increase the accuracy of tape attachment. The present invention relates to a method for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art Conventionally, a LOC (Lead on Chip) type semiconductor device has been manufactured as shown in FIGS. 4 (A) to 4 (C).
Prepare a lead frame a made of copper, and add a tape b
Are bonded by thermocompression bonding, and the lead frame a
Was bonded to the chip c via the tape b. Therefore, the lead frame a has been supplied from the lead frame maker to the semiconductor device assembly factory with the tape b adhered thereto.

The tape b is formed by forming adhesive layers e on both sides of a base d made of, for example, a polyimide resin. 2
F indicated by a dashed line is a bonding wire connecting between the lead a and the semiconductor chip c.

Recently, instead of attaching a single tape b to the lead frame a, a method of dividing the tape into a plurality of tapes and attaching the tape to the lead frame a has been adopted. This is for the purpose of suppressing stress dispersion and void generation.

[0005]

FIG. 4 (A)
First, in the conventional method for manufacturing a LOC semiconductor device as shown in FIGS. 1C to 1C, first, the temperature at which the tape b is applied is as high as several hundred degrees, so that the lead frame a is heated to a high temperature when the tape b is applied. As a result, there is a problem that the leads are deformed such as warpage and deviation, and are further oxidized. In addition, it is very difficult to attach the divided tape to the lead frame, it cannot be done without increasing the cost, and it is necessary to form the tape with the most appropriate shape for the inner lead of the lead frame with high precision Was difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and in a method of manufacturing a LOC semiconductor device, a lead frame is prevented from being heated to a high temperature by sticking a tape. An object of the present invention is to make it possible to form a tape to be attached to a shape most suitable for the shape of inner leads of a lead frame with high accuracy.

[0007]

According to a first aspect of the present invention, there is provided a method for manufacturing a LOC type semiconductor device, wherein a tape is entirely adhered to a surface of a semiconductor wafer, and the tape is patterned by selective photoetching. A step of selectively remaining on each semiconductor chip of the wafer, a step of removing the resist film used as a mask during the selective photoetching by ashing, a step of pelletizing the semiconductor wafer into a plurality of semiconductor chips, and a step of reading. A step of bonding the inner lead of the frame to the patterned tape in this order. According to a second aspect of the invention, there is provided a method for manufacturing a LOC semiconductor device, comprising: removing the resist film by ashing in the method for manufacturing a LOC semiconductor device according to the first aspect; and pelletizing the semiconductor wafer into a plurality of semiconductor chips. On the contrary, the ashing step is performed after the pelletizing step, followed by the ashing step. According to a third aspect of the invention, there is provided a method of manufacturing a LOC semiconductor device, wherein the pelletizing is performed by dicing from the back surface of the semiconductor wafer.

[0008]

According to the first aspect of the present invention, the tape is first adhered to the semiconductor wafer, and the lead frame is adhered to the semiconductor wafer via the tape adhered to the semiconductor wafer. Bonding is high temperature and does not require crimping. Therefore, there is no fear that the lead frame is deformed or oxidized due to the high temperature due to the adhesion of the tape. Further, since the tape on the semiconductor wafer is patterned by photoetching, the tape can be formed with high accuracy and fineness in consideration of prevention of void generation, stress dispersion, the shape of the inner lead, and the like. Further, since the resist film is removed by ashing before pelletizing, the resist film can be easily removed.

According to the second aspect of the present invention, the tape is first adhered to the semiconductor wafer, and the lead frame is adhered to the semiconductor wafer via the tape adhered to the semiconductor wafer. Bonding is high temperature and does not require crimping. Therefore, there is no fear that the lead frame is deformed or oxidized due to the high temperature due to the adhesion of the tape. Further, since the tape on the semiconductor wafer is patterned by photoetching, the tape can be formed with high accuracy and fineness in consideration of prevention of void generation, stress dispersion, the shape of the inner lead, and the like. Further, since the resist film is removed by ashing after pelletizing, the back surface of the tape can be protected by the resist film at the time of pelletizing, and the tape surface can be prevented from being stained at the time of pelletizing. According to the manufacturing method of the LOC semiconductor device of the third aspect, since dicing for pelletizing is performed from the back surface of the tape, it is possible to prevent the surface of the tape attached to the wafer surface from being contaminated by the dicing. .

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A to 1H are cross-sectional views showing one embodiment of a method for manufacturing a LOC semiconductor device of the present invention in the order of steps. (A) As shown in FIG. 1A, a semiconductor wafer 1 having undergone a wafer process is prepared. (B) Next, as shown in FIG. 1B, a tape 2 is bonded to the surface of the semiconductor wafer 1 by thermocompression bonding. The tape 2 has adhesives 4 and 4 on both sides of a base 3 made of polyimide resin.
Is formed.

(C) Next, a resist film 5 is applied to the surface of the tape 2 as shown in FIG. (D) Next, as shown in FIG. 1D, the resist film 5 is patterned by exposure and development. (E) Next, as shown in FIG. 1E, the tape 2 is patterned by, for example, wet etching using the resist film 5 as a mask.

(F) Next, FIG.
The resist film 5 is removed as shown in FIG. (G) Next, dicing of the semiconductor wafer 1 is performed as shown in FIG.
Pelletize as shown in (G). Reference numerals 1a, 1a,... Denote semiconductor chips generated by pelletizing the semiconductor wafer 1. In FIG. 1 (G), the tape 2 is shown with its cross-sectional structure omitted. Incidentally, the same applies to the following FIG. 1 (H).

(H) Thereafter, as shown in FIG.
The lead frame 6 is adhered to the semiconductor chip 1a via the tape 2 which is adhered to the semiconductor chip 1a and patterned as described above. Thereafter, although not shown, wire bonding between each electrode of the semiconductor chip 1a and the tip of each inner lead of the lead frame 6,
That is, wire bonding is performed, then resin sealing is performed, and thereafter, unnecessary portions of the lead frame 6 are cut and formed. There is no difference in these points from the conventional case.

According to such a method of manufacturing a LOC semiconductor device, a tape is first adhered to the semiconductor wafer 1, and the lead frame 6 is adhered to the semiconductor wafer 1 via the tape 2 adhered to the semiconductor wafer 1. Therefore, bonding of the lead frame 6 to the chip 1a does not require high temperature and pressure bonding. Therefore, there is no fear that the lead frame 6 is deformed or oxidized due to a high temperature due to the adhesion of the tape.
Further, since the tape 2 on the semiconductor wafer 1 is patterned by photo-etching, the tape 2 can be formed with high accuracy and finely in a shape that takes into consideration the prevention of voids, the dispersion of stress, the shape of the inner leads, and the like. Since the resist film 5 is removed by ashing before dicing, the resist film 5 can be easily removed.

FIGS. 2A and 2B are cross-sectional views showing the main parts of a second embodiment of the method of manufacturing a LOC semiconductor device according to the present invention in the order of steps. This embodiment is different from the embodiment shown in FIG.
The steps up to the step shown in (E) are completely the same, and these steps have already been described and illustrated, so that the description and illustration are omitted.

(A) As shown in FIG. 1 (E), the semiconductor wafer 1 after the step of etching the tape 2 using the resist film 5 as a mask is shown in FIG. 2 (A) without removing the resist film 5. Pelletize by dicing as described above. In addition, 7 is a tape to which the semiconductor wafer 1 is adhered in dicing, and 8 is a dicing blade. (B) Then, as shown in FIG. 2B, the resist films 5, 5,... Used as masks at the time of the photo-etching on the surfaces of the semiconductor chips 1a, 1a,.

According to such a method of manufacturing a LOC semiconductor device, since the surface of the tape 2 is covered with the resist film 5 at the time of dicing, dust and the like generated at the time of dicing adhere to the surface of the tape 2. There is an effect that it can be prevented, which cannot be obtained in the embodiment shown in FIG.

FIGS. 3A and 3B are cross-sectional views showing the main parts of a third embodiment of the method for manufacturing a LOC semiconductor device according to the present invention in the order of steps. This embodiment is basically the same as the embodiment shown in FIG. 1, except that dicing for pelletizing is performed from the back surface of the semiconductor wafer 1.

That is, the steps up to FIG. 1F are exactly the same as those of the embodiment shown in FIG. 1, and the photo-etching of the tape 2 and the removal of the resist film 5 are completed as shown in FIG.
Is diced with the back surface facing upward, as shown in FIG. Therefore, according to the present LOC semiconductor device manufacturing method, since the surface of the semiconductor wafer 1 is turned downward and protected by the wafer holding tape 7, dust generated by dicing may adhere to the surface of the tape 2. There is no.

The technique of performing dicing of the semiconductor wafer 1 from the back surface of the semiconductor wafer 1 is the second technique shown in FIG.
It can be applied to the embodiment of the present invention. That is, FIG.
May be performed from the back surface of the semiconductor wafer 1 instead of the front surface. Thus, the present invention can be implemented in various aspects, and there can be various variations.

[0021]

According to a first aspect of the present invention, there is provided a method of manufacturing a LOC type semiconductor device, wherein a tape is entirely adhered to a surface of a semiconductor wafer, and the tape is patterned by selective photoetching so that each semiconductor of the semiconductor wafer is formed. A step of selectively remaining on a chip, a step of removing a resist film used as a mask in the selective photoetching by ashing, a step of pelletizing the semiconductor wafer into a plurality of semiconductor chips, and an inner lead of a lead frame. And a step of bonding the patterned tape and the patterned tape in that order. Therefore, according to the manufacturing method of the LOC semiconductor device of the first aspect, the tape is first adhered to the semiconductor wafer, and the lead frame is adhered to the semiconductor wafer via the tape adhered to the semiconductor wafer. Bonding is high temperature and does not require crimping. Therefore, there is no fear that the lead frame is deformed or oxidized due to the high temperature due to the adhesion of the tape. Further, since the tape on the semiconductor wafer is patterned by photoetching, the tape can be formed with high accuracy and fineness in consideration of prevention of void generation, stress dispersion, the shape of the inner lead, and the like.
Further, since the resist film is removed by ashing before dicing, the resist film can be easily removed.

According to a second aspect of the invention, there is provided a method of manufacturing a LOC type semiconductor device, wherein the step of removing the resist film by ashing and the step of pelletizing the semiconductor wafer into a plurality of semiconductor chips are performed. And the order is reversed. Therefore, L of claim 2
According to the method of manufacturing an OC type semiconductor device, the LO
The method of manufacturing a C-type semiconductor device is common except that the resist film is removed after pelletizing.
As described above, the bonding of the lead frame does not require high temperature and pressure bonding, and
There is no danger of the lead frame being deformed or oxidized by the high temperature due to the adhesion of the tape, and the tape on the semiconductor wafer is patterned by photo-etching, so that the tape has voids. This has the effect of being able to be formed with high precision and finely in a shape that takes into account prevention, stress dispersion, the shape of the inner lead, and the like. Then, since the resist film is removed by ashing after pelletizing, the back surface of the tape can be protected by the resist film at the time of pelletizing, and the tape surface can be prevented from being stained at the time of pelletizing.

According to a third aspect of the present invention, there is provided a method for manufacturing a LOC semiconductor device, wherein dicing for pelletizing a semiconductor wafer is performed from the back surface of the semiconductor wafer. Therefore, according to the method of manufacturing a LOC semiconductor device of the third aspect, dicing is performed from the back surface of the tape.
It is possible to prevent the tape surface attached to the wafer surface from being contaminated by dicing.

[0024]

[Brief description of the drawings]

1A to 1H are sectional views showing a first embodiment of a method for manufacturing a LOC semiconductor device of the present invention in the order of steps.

FIGS. 2A and 2B are cross-sectional views showing a second embodiment of a method for manufacturing a LOC semiconductor device of the present invention in the order of steps.

FIGS. 3A and 3B are cross-sectional views showing a third embodiment of a method for manufacturing a LOC semiconductor device of the present invention in the order of steps.

4A to 4C are cross-sectional views showing a conventional example in the order of steps.

[Explanation of symbols]

 Reference Signs List 1 semiconductor wafer 2 tape 5 resist film 6 lead frame 8 blade

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 23/50 H01L 21/301

Claims (3)

(57) [Claims] A step of bonding a tape to the entire surface of a semiconductor wafer having a plurality of semiconductor chips formed thereon , and a step of selectively using the tape as a mask with a resist film as a mask.
Each of the above halves is patterned by etching.
Selectively leaving the resist film on the conductive chip, removing the resist film by ashing, and pelletizing the semiconductor wafer into a plurality of semiconductor chips.
The inner lead of the lead frame and the above-mentioned patterning.
Method for producing a LOC type semiconductor device characterized in that it comprises the step of bonding the tape, with the order 2. A step of completely bonding a tape to a surface of a semiconductor wafer having a plurality of semiconductor chips formed thereon , and a step of selectively using the tape as a mask with a resist film as a mask.
Each of the above halves is patterned by etching.
Selectively leaving the semiconductor wafer on the conductive chip; and pelletizing the semiconductor wafer into a plurality of semiconductor chips.
That step and, step a, the inner lead and the patterning of the lead frame is removed by ashing the resist film
Method for producing a LOC type semiconductor device characterized in that it comprises the step of bonding the tape, with the order 3. The method according to claim 1, wherein the pelletizing is performed from the back side of the semiconductor wafer .
Claim and carrying out by dicing 1 or 2
Of manufacturing LOC type semiconductor device