JPH03206635A - Manufacture of film-carrier semiconductor device - Google Patents

Abstract

PURPOSE:To increase the uniformity of a temperature and to increase the bonding property between a bump and a lead by a method wherein a material whose thermal conductivity is low is placed between a bonding stage and a semiconductor pellet and an inner-lead bonding operation is executed by a fixed heating system. CONSTITUTION:Inner leads 4 corresponding to bumps 6 arranged on an IC 1 in a one-to-one manner are aligned by using a mechanical positioning mechanism installed inside an ILB apparatus or an image recognition mechanism such as a pattern matching mechanism or the like; the bumps 6 are connected to the inner leads 4 by using a bonding tool 3. At this time, a heat insulating material 7 by a material whose thermal conductivity is smaller than that of a bonding stage 2 is installed on the stage 2 between the stage 2 and the IC 1. As a result, it is possible to reduce the difference between a preset temperature of the bonding tool and an actual temperature of the bonding tool at an ILB operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a film carrier semiconductor device, and particularly to inner lead bonding (hereinafter referred to as ILB) of a film carrier semiconductor device.

[Conventional technology]

Conventionally, bonding of film carrier semiconductor devices, that is, T A B (Tape Automated
ILB (Inner Bonding) method
Lead Bonding) is performed as follows. An insulating film made of polyimide (PI, polyester (PET), glass epoxy, etc.) with sprocket holes is used as a base film, a metal foil such as Cu is adhered to this base film via an adhesive, and this metal foil is photo-etched. A lead of a desired shape and a pad for electrical selection are formed by the above method, and the lead and a semiconductor pellet (hereinafter referred to as I) are formed.
Perform ILB with the bump, which is a metal protrusion provided in advance on the electrode terminal of C), by thermocompression bonding or eutectic method,
Electrical sorting and burn-in (
BT) Perform the test and then cut the lead to the desired length. At this time, in the case of multiple bottles with a large number of leads, in order to prevent the outer lead bonding part of the leads from coming apart, a method is used in which an insulating film such as polyimide is left on the outer end of the outer lead, covering the film carrier tape. It is often done. Next, outer lead bonding (hereinafter referred to as LB) is performed to bonding pads on, for example, a printed circuit board, a ceramic substrate, or a general lead frame. The film carrier semiconductor device described above has a high bonding speed because bonding can be done at once regardless of the number of leads, and it is easy to automate the assembly process such as bonding and the electrical selection process, making it suitable for mass production. It has advantages such as excellent properties.

By the way, heating methods generally used in ILB include a constant heating method and a pulse heating method. The constant heating method (hereinafter referred to as the constant heat method) is a method in which a part of the bonding tool is equipped with a heater, and by constantly passing a small current to this heater, the bonding tool is heated even when ILB is not being performed. On the other hand, the pulse heating method is a method in which a part of the bonding tool is not equipped with a heater, and a large current is passed through the bonding tool only when performing ILB, and the bonding tool is heated by Joule heat due to its own electrical resistance. It is.

Of the two types of heating methods mentioned above, the constant heat method is generally adopted. The reason for this is that the bonding temperature is lower (4
00-450℃. Vals heat method is 450-500℃
(required), less thermal influence on IC, faster bonding speed, longer life of bonding tool,
This is because the ILB bonder has advantages such as requiring only a small capacity.

The method of connecting the bump electrodes on the IC and the inner leads on the film carrier table, that is, the ILB method using such a constant heat method, will be explained with reference to FIG.

In the figure, 111 is a semiconductor IC, 666 is a bump that is a metal protrusion, 444 is an inner lead on the film carrier tape, and 333 is a bonding tool. Once mated, they are simultaneously connected by a single thermocompression bonding process using a heat and load loaded bonding tool.

[Problem to be solved by the invention]

In the conventional ILB method described above, the bonding tool is subjected to heat and load at the same time regardless of the number of bumps, so the bonding tool that is loaded with heat and load has a surface that contacts the inner lead part in order to ensure uniform heat distribution and load uniformity. A uniform surface, that is, flatness, is required, and the bumps on the IC are required to have small variations in their height, and the inner lead part of the film carrier tape is also required to have small variations in its thickness. . On the other hand, the external size of ICs is increasing due to the demand for higher integration and higher functionality, and as a result, ICs with as many as 300 to 1000 electrodes, for example, are being developed.

When performing ILB on such an IC using the TAB method, uniformity of heat and load is particularly required since connections between a large number of bumps and inner leads are performed at once regardless of the number of connections.

When a constant heat method is adopted as an ILB method under these requirements, the bonding temperature is lowered as much as possible to perform low-temperature bonding, and the bonding stage on which the IC is placed is 100 mm in order to suppress thermal damage to the IC. A method of heating to ~200°C (hereinafter referred to as base heating) is commonly used.

However, the conventional constant heat method
In the LB method, an IC is placed directly on a metal bonding stage. As a result, the IC is heated at the set temperature of the metal bonding stage (substrate heating temperature, e.g. 100-200°C), and when the so-called chip temperature has risen to, e.g. 100-200°C,
ILB is performed by heating and pressurizing with a bonding tool set at 0 to 450°C. At this time, since the heat capacity of the bonding stage including the IC is generally larger than the heat capacity of the bonding tool, the heat of the bonding tool is conducted to the bonding stage through the IC. Approximately 20 to 40
A phenomenon occurs in which the temperature drops. In other words, although ILB would normally be performed with the bonding tool at a temperature of 400 to 450°C, the actual ILB was performed at a bonding tool temperature of 360 to 410°C. This includes the problem of reducing the bondability between the bump and the inner lead. Furthermore, when ILB work is performed continuously, ILB may be performed even if the temperature of the bonding tool has not reached the initial set temperature, so there is a problem that uniformity of ILB conditions cannot be ensured.

An object of the present invention is to reduce the rate at which the temperature of the bonding tool is conducted to the bonding stage on which an IC is placed, even during ILB, in the ILB method of thermocompression bonding using a constant heating method. ILB is possible at a temperature close to the set temperature, improving the uniformity of the I L'B temperature, improving bonding between bumps and leads, and shortening the index of ILB work, improving productivity. An object of the present invention is to provide a method for manufacturing a film carrier semiconductor device that allows lead bonding.

[Means to solve the problem]

The method for manufacturing a film carrier semiconductor device of the present invention includes pressing the inner leads of the film carrier against the electrodes of the semiconductor pellet positioned on a bonding stage using a bonding tool to bond the electrodes of the semiconductor pellet and the inner leads of the film carrier together. A method for manufacturing a film carrier semiconductor device in which bonding is performed using a semiconductor pellet is characterized in that a material with low thermal conductivity is placed between a bonding stage and a semiconductor pellet, and inner lead bonding is performed by a constant heating method.

〔Example〕

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a front view of a bonding device for explaining one embodiment of the present invention. In the figure, 1 is a semiconductor IC, 2 is a bonding stage, 3 is a bonding tool, 4 is an inner lead, and 5 is a film carrier tape (base film). 6 is an IC bump, and 7 is a heat insulating material.

The bumps 6 placed on this ICI and the inner leads 4 in one-to-one correspondence are aligned using a mechanical positioning mechanism or an image recognition mechanism such as pattern matching provided in the ILB device, and then the bonding tool 3 The bump 6 and the inner lead 4 are connected. At this time, a heat insulating material 7 such as a material having a lower thermal conductivity than the bonding stage 2, such as a quartz plate, is provided on the bonding stage 2 between it and the ICI. This quartz plate (Si02
) has a thermal conductivity of approximately 1.3 (W/m-k), which is very small compared to copper's thermal conductivity of approximately 372 (W/m-k), and can almost be considered an insulating material. . When performing ILB using this method, the temperature of the bonding tool during bonding, for example when set at 450°C, will drop by about 10 to 15°C, compared to about 20 to 40°C with the conventional method. Improved. This is because by providing a heat insulating material such as a quartz plate on the bonding stage, it is possible to prevent the heat of the tool from being conducted to the bonding stage. Quartz plates have high heat resistance;
Furthermore, since it has high resistance to mechanical compressive stress, its use does not impose many restrictions on the temperature and load of the bonding tool. In this way, by using a quartz plate etc. as a heat insulating material in a constant heat type ILB, it is possible to adjust the set temperature of the bonding tool and the actual IL.
It is possible to reduce the difference between the temperature of the bonding tool during B and thereby to improve the uniformity of temperature during ILB conditions and to improve the reliability of bonding between bumps and leads. Furthermore, since the amount of temperature drop in the bonding tool is small, the time required for recovery to the original set temperature after ILB is completed is short, and therefore the indexing time in ILB work is shortened, which has the advantage of improving productivity. Although quartz board is used as an example of heat insulating material, other materials include alumina board (approximately 3
Thermal conductivity of 5 W/m-k) or the like may be used.

FIG. 2 is a front view of a bonding apparatus for explaining another embodiment of the present invention. In the figure, 2 is a bonding stage, and 8 is a heater for heating the bonding stage. 7 is a heat insulating material such as a quartz plate. When using a quartz plate as a heat insulating material, for example, the thermal conductivity of a quartz plate is approximately 1.3 (W/m-k), which is much lower than that of ordinary metal materials, and can be considered an insulating material. Since the temperature of the bonding tool itself is not O (W/m − k ), the heat of the bonding tool is conducted to the bonding stage portion 2 during ILB. In order to minimize this, a quartz plate or the like is placed as a material on the bonding stage, and the bonding stage is heated to 100 to 200 DEG C. by a heater 8. When ILB is performed using this method, the temperature of the bonding tool during bonding, for example, when set at 450°C, has been reduced by about 20 to 40°C with the conventional method, but it has been improved to a drop of about 6 to 10°C. Ru.

〔Effect of the invention〕

As described above, the present invention is an ILB method in which thermocompression bonding is performed using a constant heating method, in which a heat insulating material such as a quartz plate is placed on a bonding stage on which a semiconductor IC is placed, and ILB is performed. With this method, even during ILB, the temperature of the bonding tool using the constant heating method decreases the rate at which it is conducted to the bonding stage on which the IC is placed, and the ILB temperature is close to the tool's set temperature.
Work B becomes possible. This improves the uniformity of the ILB temperature and improves the bonding between the bump and the lead. In addition, since the amount of drop in bonding tool temperature is small, ILB
After completion, the time it takes to recover and stabilize the original set temperature is shortened, which has the effect of shortening the ILB work index and improving productivity. In addition, the bonding stage is heated to 100 to 2
If it is heated to 00°C, the drop in the set temperature will be significantly reduced, making it more effective.

[Brief explanation of drawings]

FIG. 1 is a front view of a bonding device for explaining one embodiment of the present invention, FIG. 2 is a front view of a bonding device for explaining another embodiment of the present invention, and FIG. 3 is a front view of a bonding device for explaining an embodiment of the present invention. FIG. 2 is a front view of a bonding device for explaining inner lead bonding of a carrier semiconductor device.

Claims (1)

[Claims] In the method for manufacturing a film carrier semiconductor device, the method for manufacturing a film carrier semiconductor device includes pressing the inner leads of the film carrier against the electrodes of the semiconductor pellet positioned on the bonding stage with a bonding tool to bond the electrodes of the semiconductor pellet and the inner leads of the film carrier at once. A method for manufacturing a film carrier semiconductor device, characterized in that a material with low thermal conductivity is placed between a bonding stage and the semiconductor pellet, and inner lead bonding is performed by a constant heating method.