JPH02246237A - Film carrier - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] Regarding the film carrier used in the TAB process, the purpose is to make it possible to measure the bonding temperature between the bang and the lead by using the lead, and to make it possible to measure the bonding temperature between the bang and the lead by using the lead. At least one lead among the plurality of leads formed on the thermocouple is formed of different metals constituting the thermocouple, the different metals are joined at the tips of the leads, and a pad is provided at the base end of the leads. Configure.

[Industrial Application Field] This invention relates to a film carrier used in the TAB process.

In recent years, wire bonding has been replaced with wire bonding for wiring between chips and packages in the manufacturing process of semiconductor devices.
(Tape Autonated Bonding)
The wiring structure of this method has been put into practical use. In the wiring process using TAB, leads formed in advance on a film carrier are thermocompressed and bonded to bumps formed on the chip using solder, gold, or the like.

[Prior art] Conventionally, in the TAB process, in order to adjust the bonding temperature when thermocompression bonding a lead to a bump, a thermocouple is attached to the crimping part of a bonding device that presses the lead while heating it, and the thermocouple is connected to the bump. The heating temperature of the crimp part was measured based on the thermoelectromotive force generated.

[Problems to be Solved by the Invention] The above-mentioned bonding temperature measurement means measures the heating temperature of the crimping part instead of measuring the temperature of the heated lead or bump itself, so it is difficult to measure the accuracy of the lead or bump. Furthermore, if the crimping part is replaced or the chip to which the leads are crimped is changed, the junction temperature reproduced from the measurement data may differ from the actual junction temperature of the lead or bump. There is a possibility that the actual bonding temperature may be further deviated, and there is a problem that the actual bonding temperature cannot be accurately reproduced, and that the temperature distribution of the crimping part itself becomes uneven due to the attachment of the thermocouple to the crimping part.

An object of the present invention is to provide a lead structure that makes it possible to measure the bonding temperature between a bump and a lead.

[Means for solving the problem] FIG. 1 is an explanatory diagram of the principle of the present invention. That is, at least one lead 4 among the plurality of leads formed on the base film 2 so as to be bonded to one chip is made of dissimilar metals 5 and 6 constituting the thermocouple. The dissimilar metals 5.degree.6 are joined at the tips of the leads 4, and the base ends of the leads 4 are provided with pads 5a, 6a.

[Function] Since the tip of the lead 4 constitutes a thermocouple, the bonding temperature between the tip of the lead 4 and the bang is equal to that of the pad 5 at the base end of the lead 4.
It is detected as a thermoelectromotive force from a and 6a.

[Example] Hereinafter, an example embodying the present invention will be described with reference to FIGS. 2 to 4. The film carrier 1 shown in FIG.
A square hole 3 is formed in the center of the base film 2, and leads 4 are formed around the square hole 3, and the tips of each lead 4 protrude into the square hole 3.

Each lead 4 is formed by joining together different metals that constitute a thermocouple. That is, as shown in FIG.
A pair of chromel 5 and alumel 6 formed in parallel on a base film 2 are joined at their tips, and their surfaces are tin-plated. A predetermined gap 7 is formed between the chromel 5 and the alumel 6 except for the joint portion, so that the chromel 5 and the alumel 6 are insulated. Note that the gap 7 can also be filled with an insulating material such as polyimide resin.

Pads 5 are provided at the proximal ends of chromel 5 and alumel 6, respectively.
a, 6a are formed, and the proximal end of the alumel 6 is bent at a right angle to provide a predetermined spacing between both pads 5a, 6a.

Now, in the TAB process using the film carrier 1 configured as described above, the chip 8 is positioned in the square hole 3 of the base film 2 as shown in FIG.
With the tip of each lead 4 aligned with the bump 9 formed in advance on the
When the tip is heated and pressed against the bump 9, an alloy is formed between the bump 9 made of solder or gold and the tin plated on the lead 4, and the lead 4 is pressed against the bump 1.
9.

At this time, when a detection bus for detecting a thermoelectromotive force is applied to the pads 5a and 6a of each lead 4, a thermoelectromotive force based on the bonding temperature between the tip of each lead 4 and the bump 9 is detected, and the thermoelectromotive force is detected. Junction temperature is detected based on the power. After bonding, the leads 4 are cut in the square hole 3 of the film carrier 1 and the process moves to the next step.

As mentioned above, TA using this film carrier 1
In process B, the bonding temperature between each lead 4 and the bump 9 is detected via the thermocouple at the tip of each lead 4, so the bonding temperature can be detected accurately and the bonding temperature at the tip of each lead 4 can be detected. It is also possible to detect variations in Therefore, the bonding state between the leads 4 and the bumps 9 can be controlled accurately. Further, since the temperature of the bonding portion is directly detected, the bonding temperature can be accurately detected even when the crimp portion 10 of the bonding device is replaced.

In the above embodiment, the lead 4 was formed by forming the chromel 5 and the alumel 6 in parallel on the base film 2, but as shown in FIG.
It is also possible to form a lead by laminating alumel 6 and chromel 5 with an insulating layer 11 interposed therebetween, and joining the tips of the alumel 6 and chromel 5.

[Effects of the Invention] As detailed above, the present invention exhibits the excellent effect of providing a lead structure that enables accurate measurement of the bonding temperature between a bump and a lead.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a front view showing a film carrier of an embodiment embodying the invention, Fig. 3 is a front view showing the tip of the lead, and Fig. 4 is a front view showing the lead tip. FIG. 5 is a schematic view showing the bonding process, and a sectional view showing another embodiment of the lead. In the figure, 2 is a base film, 4 is a lead, 5 degrees.

Claims (1)

[Claims] 1. Place the base film (2
) of the plurality of leads (4) formed on the dissimilar metals (5, 6) constituting the thermocouple.
A film carrier characterized in that the dissimilar metals (5, 6) are joined at the tips of leads (4), and pads (5a, 6a) are provided at the base ends of the leads (4). .