JP2751726B2 - Method for manufacturing film carrier 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 semiconductor device, and more particularly to a method for manufacturing a film carrier semiconductor device.

[0002]

2. Description of the Related Art A conventional film carrier semiconductor device has a base film made of an insulating film made of polyimide, polyester, glass epoxy or the like having a sprocket hole for carrying and positioning and a device hole which is an opening for a semiconductor chip. A metal foil such as Cu is adhered to the film via an adhesive, and the metal foil is patterned by etching or the like to form a lead and an electrical selection pad. ILB (inner lead bonding) is performed on the provided bumps, which are metal protrusions, by a thermocompression bonding method or a eutectic method, and an electrical selection or a BT test is performed in a state of a film carrier tape. Cut into pieces.

At this time, in the case of a large number of pins having a large number of leads, an insulating film such as polyimide constituting a film carrier tape is left at the outer ends of the outer leads in order to prevent the outer lead bodging portion of the leads from scattering. Techniques are often used. Next, for example, outer lead bonding (OLB) is performed on a bonding pad on a printed board or a general lead frame.

Such a film carrier semiconductor device has a high bonding speed because bonding can be performed simultaneously at a time irrespective of the number of leads, and it is easy to automate the assembly and electrical sorting work of bonding and the like, and mass production is possible. Has the advantage that it is excellent.

Next, the connection between the bumps of the semiconductor chip and the inner leads on the film carrier tape, ie, ILB
The method will be described.

FIG. 7A is a front view of an example of a conventional film carrier tape, and FIG. 7B is a sectional view taken along line XX of FIG. 7A. However, for the sake of explanation, a thermocompression jig (only the shape of the bottom surface is shown in FIG. 7A) is shown. In the figure, 1 is a semiconductor chip, 2 is a bump as a metal projection, 3 is an inner lead on a film carrier tape,
Reference numeral 4 denotes a thermocompression jig, which is used after the bumps 2 and the inner leads 3 on the surface of the semiconductor chip 1 are aligned.
Bonding is performed simultaneously by a single thermocompression bonding using a thermocompression jig 4 to which heat and a load are applied.

However, since such a method of manufacturing a film carrier semiconductor device is performed simultaneously at a time regardless of the number of bumps, the thermocompression bonding jig to which heat and load are applied has uniform heat distribution and uniform load. The surface in contact with the inner lead portion must have a uniform surface, that is, flatness, so that the bumps have reduced height variations, and the film carrier tape inner lead portions also have reduced thickness variations. Is required. On the other hand, ICs are becoming more highly integrated and more sophisticated, and the outer size of the semiconductor chip is becoming larger.
As many as 100-600 are being developed. When such a film carrier semiconductor device is formed by the conventional ILB method, a large number of bumps and inner leads are bonded at one time. Since the applied load required for bonding per electrode is almost the same, a large number of pins are bonded. The load required for the thermocompression bonding jig increases in proportion to the change in the size.
kg is also required.

The heat distribution of the thermocompression bonding jig required for bonding is such that the outer size of the semiconductor chip is 10 × 10 to 15 × 15 mm.
Even if the size is increased to about ² , it is required to be uniform, and its accuracy is ± 5 to 7 ° C. Therefore, the load at the time of thermocompression bonding is increased due to the increase in the size of the IC and the increase in the number of pins, and the uniformity of the heat distribution of the thermocompression jig and the flatness of the thermocompression jig need to be improved. come. In other words, only a few to dozens of bumps during ILB due to the manufacturing accuracy of the semiconductor chip bumps, especially the thickness variation and the accuracy of the thermocompression jig and the ILB device, particularly the inclination or flatness, parallelism, etc. The load and heat are concentrated instantaneously, and a strong stress is applied to the bump, and the bump is short-circuited to the next bump, or the bump is peeled off from the interface between the silicon substrate or the insulating film and the bump.
To lower the connection strength and destroy the semiconductor chip itself.

On the other hand, the load and heat during ILB are insufficient, and peeling from the interface between the bump and the inner lead occurs, which lowers the bonding strength.

This tendency becomes conspicuous as the size of the IC increases and the number of pins increases, and the reliability of the IC decreases significantly.

As described above, in the conventional manufacturing method, since the connection between the bump and the lead is performed simultaneously at one time, there is a problem that the reliability of the connection is reduced, and the accuracy of the bump and the lead, particularly in the thickness direction, is reduced. Improvement and thermocompression jig and I
Measures to improve the accuracy of the LB device, especially for parallelism, etc.
This has become very difficult with the increase in size and the number of pins. In order to solve this problem, there is a method in which the bonding between the plurality of bumps arranged on the semiconductor chip and the inner leads of the plurality of film carrier tapes corresponding to each of the bumps is divided into a plurality of times and thermocompression-bonded. Is being developed.

The method of bonding the bumps of the IC and the inner leads on the film carrier tape, that is, the single point ILB will be described.

FIG. 8A is a plan view (showing a quarter of the whole) used to explain the single point ILB, and FIG. 8B is a line XX of FIG. 8A. It is sectional drawing.

In the drawing, 1 is a semiconductor chip, 2 is a bump, 3 is an inner lead on a film carrier tape,
Reference numeral 41 denotes a thermocompression jig. The thermocompression jig 41 to which heat and a load are applied after the bumps 2 of the semiconductor chip and the inner leads 3 are aligned with each other, a pair of each of the bumps and each of the inner leads 1 They are joined sequentially in pairs.

In the ILB method in which the bump and the inner lead are combined as described above, the ILB device does not require a complicated mechanical mechanism, and accordingly, the size and cost of the ILB device can be reduced. The heat and the load applied to the thermocompression jig 41 are such that the outside diameter of the thermocompression jig becomes very small with respect to the outside diameter of the IC.
× 15 mm tip outer diameter of ² even thermocompression bonding jig 0.1 ×
In the case of 0.1 mm ² , the heat distribution at the tip of the thermocompression bonding jig is within ± 1 ° C, and the load applied to the thermocompression jig can be several tens g to several hundred g. . Further, it goes without saying that the parallelism between the thermocompression bonding jig and the bump on the IC can be easily adjusted.

[0016]

In the above-mentioned conventional method for manufacturing a film carrier semiconductor, the bumps and the inner leads corresponding to the bumps are sequentially and repeatedly repeated ILB. When the ILB is completed, the adjacent bumps are formed. Alternatively, it is required that the inner leads do not contact each other. If the adjacent bumps or inner leads come into contact with each other, a short circuit is caused electrically, and it is very difficult to repair the short circuit. On the other hand, ICs are becoming more highly integrated and more sophisticated, and the outer diameter of the semiconductor chip is becoming larger. As a result, the number of IC electrodes is, for example, 200 to 600, or even 700 to 1000. Things are being developed. If the outer diameter of the semiconductor chip is 15 mm × 15 mm, for example, the
When the number of the electrodes is 0, the pitch of the electrodes or bumps is about 100
μm, and the size of the bump is about 60 μm × 60 μm. Furthermore, the outer diameter size of the semiconductor chip is 15 mm x 15
When the number of bumps is 1,000 in mm, the bump pitch is about 60 μm, and the bump size is about 40 μm × 40 μm. That is, in each case, the space between bumps is about 4
0 μm and about 20 μm.

In the conventional bonding between a bump and an inner lead, that is, in the ILB, several kinds of combinations of materials for the bump and the inner lead are possible. For example, Au, C
Au, Sn, etc. for surface treatment of u, solder, etc. or inner leads
Solder plating and the like are used, and the combination having the highest connection reliability among these is Au plating in which the bump is Au plating and the surface treatment of the inner lead is the same. The thermocompression bonding method is applied to the Au-Au ILB. In the Au-Au thermocompression bonding method, heat and pressure are applied to each of the bump and the inner lead portion, and the bonding is performed using thermal diffusion accompanied by plastic deformation. Therefore, if reliable ILB is performed, the bumps and the inner leads need to be plastically deformed. Therefore, as the pitch between the bumps becomes narrower (for example, 40 to 60 μm pitch), adjacent bumps after the ILB are formed. The contact between the bumps and the inner leads is more likely to occur, and the problem of lowering the connection reliability becomes noticeable.

[0018]

According to a method of manufacturing a film carrier semiconductor device of the present invention, a plurality of bumps provided on a surface of a semiconductor chip are preliminarily joined by corresponding inner leads of a film carrier tape to the bumps. And applying a thermosetting insulating resin material to the surface of the semiconductor chip at least at the height of the inner leads.
Heating and pre-curing the thermosetting insulating resin material; and performing thermocompression bonding to promote thermosetting of the thermosetting insulating resin material and complete the bonding between the bump and the inner lead. And a process.

In addition, preliminary bonding is performed by a thermocompression bonding method.
The thermosetting insulating resin material may be applied in a state where the inner lead is pressed by the thermocompression bonding jig.

[0020]

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

FIG. 1 (a) is a plan view used for explaining a method of manufacturing a film carrier semiconductor device according to a first embodiment of the present invention. (Only the shape shown in the figure) is applied. FIG. 1B is a cross-sectional view taken along line XX of FIG. FIGS. 2A to 2D are cross-sectional views showing states in respective steps subsequent to FIG. 1B.

First, as shown in FIG. 1, a bump 2 provided on a surface portion of a semiconductor chip 1 and an inner lead 3 corresponding to a pair respectively are provided with a mechanical positioning mechanism provided in an ILB device and a pattern matching. Alignment is performed by a recognition mechanism such as, for example, with a thermocompression bonding jig 42, for a 600-pin IC, for example, a load of 25 kg, a temperature of 450 to 500 ° C., and a time of 1 hour.
The bump and the inner lead are preliminarily bonded by thermocompression bonding under the ILB condition of seconds. That is, pressure is applied to the extent that the bumps or inner leads do not contact adjacent bumps or inner leads. In addition, the semiconductor chip 1
Are mounted on a bonding stage at room temperature. Next, as shown in FIG. 2A, the thermocompression bonding jig 42 is moved upward, and then, as shown in FIG. Fifteen
(Curing is almost completed by heat treatment at 0 ° C. for about 1 hour) or the like is applied to the height of the inner lead 3 or more by a method such as potting. Then, the applied thermosetting resin 5 is preliminarily cured by performing radiation heating at, for example, 150 ° C. for about 10 seconds.

Finally, as shown in FIG. 2 (c), the thermocompression jig 42 is placed on the thermosetting insulating resin 5 with a load of 50 kg, a temperature of 150 to 160.degree.
Bump 2 by heating and pressing again under the condition of ~ 3 seconds.
And bonding of the inner lead 3 to the thermosetting resin 5
Accelerates curing.

As described above, the bumps of the semiconductor chip and the inner leads on the film carrier tape are preliminarily joined, a thermosetting insulating resin is applied to the surface of the semiconductor chip at a height equal to or higher than the height of the inner leads, and is preliminarily heated and cured. After that, the thermocompression jig is again heated and pressed from above the thermosetting resin to complete the bonding of the bump and the lead, and to shape the thermosetting insulating resin, and to promote the curing. The contact between adjacent bumps and inner leads after ILB, which is likely to occur when the pitch between bumps provided on a certain semiconductor chip is as narrow as 40 to 60 μm, for example, is achieved by the interposition of a thermosetting insulating resin. It is possible to prevent a decrease in reliability and a decrease in manufacturing yield.

Further, since a potting nozzle is installed in the ILB device, the surface of the semiconductor chip can be protected by applying a thermosetting insulating resin simultaneously with the bonding of the bumps of the semiconductor chip and the inner leads. Therefore, there is no need to provide a potting step and a potting device, and the process can be reduced and the mass productivity can be improved.

FIG. 3 (a) is a plan view used for explaining a method of manufacturing a film carrier semiconductor device according to a second embodiment of the present invention. (Only the shape of FIG. 1 is shown). FIG. 3B is a sectional view taken along line XX of FIG.
(A), (b), FIGS. 5 (a), (b), and FIG. 6 are cross-sectional views showing the state in each of the subsequent steps.

First, as shown in FIGS. 3A and 3B,
A machine in which a semiconductor chip 1A in which only bumps 2A are present on two opposing sides is mounted on a bonding stage 7 heated to a temperature of 150 ° C., and inner leads 3A corresponding to the bumps 2A and a pair are provided in an ILB device. (FIG. 4 (a)), and a thermocompression jig 4 on the concave getter is used.
3 so that the bumps or inner leads do not contact adjacent bumps or inner leads, for example, 30
For a 0-pin IC, load 15kg, temperature 150 ℃, time 2
Preliminary bonding under ILB conditions of ~ 3 seconds (Fig. 4
(B)).

Next, as shown in FIG. 5A, the thermocompression jig 43 is kept pressed against the lead 3, and the thermocompression jig 43 and the space formed on the surface of the semiconductor chip are heated. The thermosetting insulating resin 5 is passed through the nozzle 6 for applying the curable insulating resin.
A For example, while dropping a silicone resin or the like (a curing temperature of 150 ° C.) onto the inner lead 3 or higher, the preliminary heating is performed by heating the bonding stage 7 to, for example, 140 to 150 ° C. and heating the thermocompression jig 43. To cure.

Finally, the thermocompression bonding jig 43 is further set to, for example, 30 k
By pressing with g, the bonding between the bumps 2 and the leads 3 is completed, and the thermosetting resin 5Aa is shaped to promote hardening. As shown in FIG. 6, the thermocompression jig 43 is moved.

As described above, in the second embodiment, as in the first embodiment, after the bumps and the inner leads are preliminarily joined, a thermosetting insulating resin is applied to the height of the inner leads and preliminarily cured. After that, the thermocompression bonding jig is further pressurized to complete the bonding of the bump and the lead, and to promote the curing of the thermosetting insulating resin, so that the pitch between bumps, which is a conventional problem, is reduced to, for example, 40 to 60 μm. In this case, the mutual contact between the adjacent bumps and the inner leads after the ILB, which is likely to occur in the event of the occurrence of the ILB, can be prevented by the interposition of the thermosetting insulating resin, and the reliability and the production yield can be prevented.

Further, in this embodiment, the thermosetting insulating resin is dropped while the lead is pressed by the thermocompression jig, so that the thermosetting insulating resin is heated only by heating the thermocompression jig and heating the base of the bonding stage. There is an advantage that it can be cured and can be carried out without using a heating device for curing the resin.

[0032]

As described above, the present invention is applied to a thermocompression jig which is dropped on the height of the bump of the semiconductor chip and the inner lead of the film carrier tape or higher, and is preliminarily heated and cured. The method of manufacturing a film carrier semiconductor device in which the bonding between the bump and the inner lead is completed by heating and pressurizing again and the hardening of the thermosetting insulating resin is promoted. Therefore, the pitch between bumps, which is a conventional problem, is, for example, 40 to 60 μm. The mutual contact between the adjacent bumps and the inner leads after the ILB, which tends to occur when the pitch becomes narrow, can be prevented by the interposition of the thermosetting insulating resin, and the reliability and the production yield can be prevented from lowering. It has the effect of.

[Brief description of the drawings]

FIG. 1 is a plan view (FIG. 1 (a)) and a cross-sectional view (FIG. 1 (b)) used for explaining a first embodiment of the present invention.

FIG. 2 is a cross-sectional view in the order of steps used for explaining a first embodiment of the present invention.

FIGS. 3A and 3B are a plan view (FIG. 3A) and a cross-sectional view (FIG. 3B) used for describing a second embodiment of the present invention.

FIG. 4 is a cross-sectional view in the order of steps used for explaining a first embodiment of the present invention.

FIG. 5 is a cross-sectional view in the order of steps used for explaining the first embodiment of the present invention.

FIG. 6 is a cross-sectional view used for describing a first embodiment of the present invention.

FIG. 7 is a plan view (FIG. 7) used to explain a conventional technique;
(A)) and sectional drawing (FIG.7 (b)).

8A and 8B are a plan view (FIG. 8A) and a cross-sectional view (FIG. 8B) used for describing a single point ILB.

[Explanation of symbols]

1,1A Semiconductor IC 2,2a, 2b, 2A, 2Aa, 2Ab Bump 3,3a, 3b, 3A, 3Aa, 3Ab Inner lead 4,41,42,43 Thermocompression jig 5,5a, 5A, 5Aa Thermosetting Insulating resin 6 Resin coating nozzle 7 Bonding stage

Claims (2)

(57) [Claims] A step of preliminarily bonding a plurality of bumps disposed on a surface of the semiconductor chip to respective inner leads of the film carrier tape, and applying a thermosetting insulating resin material to the surface of the semiconductor chip. A step of applying at least at the height of the inner lead; a step of heating and preliminarily curing the thermosetting insulating resin material; and performing thermocompression bonding to promote thermosetting of the thermosetting insulating resin material. And simultaneously completing the joining of the bump and the inner lead. 2. A step of preliminarily bonding the inner leads of the film carrier tape to each of the plurality of bumps provided on the surface portion of the semiconductor chip by a thermocompression bonding method, and using a thermocompression jig. Pressing a thermosetting insulating resin material on the surface of the semiconductor chip and preliminarily curing the same while holding down the bumps, and promoting thermosetting of the thermosetting insulating resin material by performing thermocompression bonding while simultaneously forming the bumps. And a step of completing the joining of the inner leads.