KR100517331B1 - Anisotropic conductive films used for cof and tcp - Google Patents

Abstract

In the present invention, in the anisotropic conductive film, a COF and TCP combined anisotropic conductive film containing a modified polyimide or polyamic acid are disclosed. It is preferable that activation temperature of said modified polyimide or polyamic acid is 150-180 degreeC, and it is more preferable to contain 0.1-70 weight part with respect to 100 weight part of anisotropic conductive films. The anisotropic conductive film according to the present invention can be used as a combination of TCP and COF, and will have characteristics of high adhesion and connection resistance reliability.

Description

Anisotropic conductive film combined with COF and TC {ANISOTROPIC CONDUCTIVE FILMS USED FOR COF AND TCP}

The present invention relates to an anisotropic conductive film for both COF and TCP, and more particularly, to an anisotropic conductive film for both COF and TCP, including modified polyimide or polyamic acid.

Electronic packaging technology is a very diverse and diverse system fabrication technology that covers all stages from semiconductor devices to final products, and determines the performance, size, price, and reliability of the final product.

Recently, the necessity of connecting a large number of narrow-gap electrodes is increasing in electronic packaging due to the fine gap of the circuit and the increase in the connection density. Accordingly, in LCD packaging, a flexible printed circuit (FPC) and a glass display are required. A conductive adhesive is used to connect to the glass display.

The conductive adhesive is largely anisotropic conductive film, isotropic conductive adhesive, etc., basically, conductive particles such as nickel (Ni), nickel / polymer (Ni / Polymer), silver (Ag), and thermosetting or thermoplastic insulation It is composed of resin (insulating resin).

Among these, anisotropic conductive films, which are frequently used, are composed of conductive particles and insulating adhesives. Carbon conductive fibers were initially used, and then solder balls were used, and then nickel balls were used. Or Ag balls are still in use.

Silver balls are easy to use as conductive particles due to their reasonable price, high electrical conductivity, and good chemical stability, but there are problems of ion migration. Nickel ball has a low price and relatively good electrical conductivity, but there are problems of surface corrosion and oxidation at high temperature and high humidity. Therefore, gold (Au) is coated instead of silver or nickel to improve the properties of the conductive particles.

On the other hand, when the TCP is connected to the liquid crystal panel and the printed wiring board, the anisotropic conductive adhesive must satisfy the fast curing property of 6 to 10 seconds and the shelf life of 1 year or more. do.

In addition, when COF is connected to the liquid crystal panel and the printed wiring board, the anisotropic conductive adhesive must satisfy the fast curing property of 6 to 10 seconds and the storage life of at least 1 year. .

However, as a conventional anisotropic conductive adhesive, anisotropic conductive adhesive having satisfactory physical properties has not been reported yet so that it can be used simultaneously for TCP and COF.

Therefore, the present invention has been made to solve the above problems,

An object of the present invention is to provide a COF and TCP combined anisotropic conductive film that can be used simultaneously for TCP and COF, and excellent in adhesion and connection resistance reliability.

The above object of the present invention is achieved by a COF and a TCP combined anisotropic conductive film containing a modified polyimide or polyamic acid in the anisotropic conductive film.

And the said modified polyimide or polyamic acid has preferable activity temperature of 150-180 degreeC, and it is more preferable to contain 0.1-70 weight part with respect to 100 weight part of anisotropic conductive films.

Hereinafter, the COF and TCP dual use anisotropic conductive films according to the present invention will be described in detail.

The COF and TCP combined anisotropic conductive film according to the present invention includes a modified polyimide or polyamic acid which is a precursor of polyimide.

First, the modified polyimide is processed in a liquid form so that the polyimide can be cured at low temperature and low pressure, and polyamic acid is a precursor of polyimide.

It is preferable that especially the said modified polyimide and polyamic acid are 150-180 degreeC of active temperature from a viewpoint of adhesive force and connection resistance reliability.

Moreover, it is preferable that 0.1-70 weight part of said modified polyimide and polyamic acid are contained with respect to 100 weight part of anisotropic conductive films from a viewpoint of adhesive force and connection resistance reliability, as also seen from the following Example.

The polyimide is subjected to two stages of polymerization.

1 is a reaction diagram showing a step of forming a polyamic acid during a polymerization step of a polyimide. As shown in FIG. 1, as the first step of the polymerization step of the polyimide, the aromatic dianhydride and the aromatic diamine react to form polyamic acid, which is a precursor of the polyimide.

FIG. 2 is a reaction diagram illustrating a step of curing the polyamic acid formed in FIG. 1. As shown in FIG. 2, when heat and pressure are applied to the formed polyamic acid during curing as a second step of the polymerization of the polyimide, the polyamic acid is cured to form a polyimide.

As a polyimide resin, for example, UBE's UPA-AH, UPA-83, UPA-85, UPA-N111 and the like are used.

Since the modified polyimide or polyamic acid which is a precursor of the modified polyimide is cured at low temperature and low pressure, curing conditions are similar to those of the anisotropic conductive film. Therefore, when bonding the anisotropic conductive film is cured together to realize a high adhesion, reliability, physical properties and the like.

In addition, the peroxy radical of the modified polyimide or polyamic acid does not react with other components of the anisotropic conductive film and thus does not affect other physical properties of the anisotropic conductive film.

Hereinafter, the present invention will be described in more detail by explaining preferred embodiments of the present invention. However, the present invention is not limited to the following examples, and various forms of embodiments can be implemented within the scope of the appended claims, and the following examples are only common to those skilled in the art to complete the present disclosure. It is intended to facilitate the implementation of the invention to those with knowledge.

EXAMPLE

In this embodiment, an anisotropic conductive film using UPA-AH in polyimide-based resin (Example 1), an anisotropic conductive film using UPA-83 in polyimide-based resin, and a conventional anisotropic conductive film (comparative example) were prepared After bonding, ITO-TCP and ITO-COF were bonded 30 times for each bonding condition.

Table 1 shows the prescription of each of Examples and Comparative Examples.

Example KR-909 UME 315 G-0240 2-Ethylhexyl acylate Actiane 120 TP 25 UPA-AH Tolune MEK Au ball 20 4.5 2.5 15 2.5 12 10 30 3.5 Example KR-909 UME 315 G-0240 2-Ethylhexyl acylate Actiane 120 TP 25 UPA-83 Tolune MEK Au ball 20 4.5 2.5 15 2.5 12 10 30 3.5 Comparative example KR-909 UME 315 G-0240 2-Ethylhexyl acylate Actiane 120 TP 25 - Tolune MEK Au ball 26 4.5 4.5 18.5 3 - 10 30 3.5

Tables 2 to 5 show the results of initial adhesion and connection resistance measurement according to the bonding conditions of Examples 1 and 2, Comparative Example, Table 2 is TCP-ITO adhesion, Table 3 is COF-ITO adhesion, Table 4 is TCP-ITO Connection Resistance, Table 5 shows the COF-ITO connection resistance. The pressure was fixed at 2.5 MPa and the adhesion was measured with a push-pull gauge.

TCP-ITO Adhesion (gf / cm) 150 ℃ 160 ℃ 170 ℃ 180 ℃ Example 1 7 sec 1293 1323 1320 1380 10 sec 1312 1427 1430 1423 Example 2 7 sec 1298 1348 1320 1359 10 sec 1303 1442 1423 1430 Comparative example 7 sec 1034 1004 1148 1173 10 sec 1159 1183 1223 1280

COF-ITO Adhesion (gf / cm) 150 ℃ 160 ℃ 170 ℃ 180 ℃ Example 1 7 sec 1210 1320 1315 1410 10 sec 1243 1418 1380 1454 Example 2 7 sec 1232 1320 1342 1420 10 sec 1230 1453 1380 1450 Comparative example 7 sec 280 298 305 370 10 sec 295 302 310 400

TCP-ITO connection resistance 150 ℃ 160 ℃ 170 ℃ 180 ℃ Example 1 7 sec 0.4 0.4 0.3 0.3 10 sec 0.3 0.3 0.3 0.3 Example 2 7 sec 0.4 0.3 0.3 0.3 10 sec 0.4 0.3 0.3 0.3 Comparative example 7 sec 0.4 0.4 0.3 0.3 10 sec 0.3 0.3 0.3 0.3

COF-ITO connection resistance (Ω) 150 ℃ 160 ℃ 170 ℃ 180 ℃ Example 1 7 sec 0.4 0.3 0.3 0.3 10 sec 0.3 0.3 0.3 0.3 Example 2 7 sec 0.4 0.3 0.3 0.3 10 sec 0.3 0.4 0.3 0.3 Comparative example 7 sec 0.9 0.9 0.8 0.8 10 sec 0.8 0.9 0.8 0.7

Table 6 shows the results of observing the change in the adhesive force and the connection resistance for 4 weeks at 1 week intervals after bonding TCP-ITO at 180 ° C., 10 seconds, 2.5 MPa in Examples 1 and 2, and Table 7 Shows the results of observing the change of the adhesive force and the connection resistance for 4 weeks at 1 week intervals after TCP-ITO bonding, COF-ITO bonding at 180 ° C., 10 seconds, 2.5 MPa will be.

TCP-ITO reliability measurement results (85 ℃, 85% constant temperature and humidity conditions) Early 1 week 2 weeks 3 weeks 4 Weeks Example 1 Adhesive force (gf / cm) 1423 1421 1310 1284 1121 Connection resistance 0.3 0.3 0.4 0.4 0.4 Example 2 Adhesive force (gf / cm) 1450 1432 1350 1292 1142 Connection resistance 0.3 0.3 0.4 0.3 0.4 Comparative example Adhesive force (gf / cm) 1280 1220 1103 1034 900 Connection resistance 0.3 0.3 0.4 0.4 0.4

COF-ITO reliability measurement results (85 ℃, 85% constant temperature and humidity conditions) Early 1 week 2 weeks 3 weeks 4 Weeks Example 1 Adhesive force (gf / cm) 1423 1421 1310 1284 1121 Connection resistance 0.3 0.3 0.4 0.4 0.4 Example 2 Adhesive force (gf / cm) 1430 1391 1328 1259 1125 Connection resistance 0.3 0.3 0.3 0.4 0.4 Comparative example Adhesive force (gf / cm) 400 230 100 80 50 Connection resistance 0.7 OFF OFF OFF OFF

As can be seen from Tables 2 to 5, the conventional anisotropic conductive film of Comparative Example showed an initial adhesive strength of about 1000 g / cm when used in TCP, but when used in COF, the initial adhesive force was measured to be about 400 gf / cm or less. And COF combined use was found to be impossible.

However, the anisotropic conductive films of Examples 1 and 2 exhibited remarkably improved adhesive strength as the adhesive force was greater than 1300 gf / cm in both TCP and COF within various temperature and time ranges.

In addition, in the case of the initial connection resistance, in the case of Examples 1 and 2, it turned out that electroconductivity was also enough within 0.5 kPa.

On the other hand, as shown in Table 6, 7, after 4 weeks of 85 ℃, 85%, the result of the reliability measurement, the connection resistance of Examples 1 and 2 was 0.3 ~ 0.4 kW did not show a big difference from the initial value, Comparative Example In case of TCP, 0.3 ~ 0.4Ω was shown, but in case of COF, connection resistance was OFF.

The adhesive force of Example 1 was measured at a high value of 1121 gf / cm, which is about 80% of the initial adhesive force, and the adhesive force of Example 2 was measured at a high value of 1125 gf / cm, which is about 80% of the initial adhesive force. In the comparative example, in the case of TCP, adhesion was maintained about 70% of the initial value, but in the case of COF, the adhesion was hardly measured.

As a result, in the case of Examples 1 and 2, unlike the comparative example, it can be used as an anisotropic conductive film for fast curing for both TCP and COF, and it was confirmed that the adhesive strength and the connection resistance reliability were high.

The anisotropic conductive film according to the present invention can be used for both TCP and COF, and has a property of high adhesion and connection resistance reliability.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

1 is a reaction diagram showing the step of forming a polyamic acid,

FIG. 2 is a reaction diagram illustrating a step of curing the polyamic acid of FIG. 1.

Claims (7)

In the anisotropic conductive film, An anisotropic conductive film for both COF and TCP, comprising a modified polyimide. The method of claim 1, The modified polyimide is an anisotropic conductive film for both COF and TCP, characterized in that the active temperature is 150 ~ 180 ℃. The method according to claim 1 or 2, The modified polyimide is 0.1 to 70 parts by weight based on 100 parts by weight of the anisotropic conductive film, characterized in that the COF and TCP combined anisotropic conductive film. In the anisotropic conductive film, COF and TCP combined anisotropic conductive film comprising a polyamic acid. The method of claim 4, wherein The polyamic acid is an anisotropic conductive film for both COF and TCP, characterized in that the active temperature is 150 ~ 180 ℃. The method according to claim 4 or 5, The polyamic acid is 0.1 to 70 parts by weight based on 100 parts by weight of the anisotropic conductive film, COF and TCP combined anisotropic conductive film, characterized in that. The method of claim 6, Wherein said polyamic acid is formed from aromatic di & hydride and aromatic diamine.