KR20090115053A - Complex Sheet - Google Patents

Abstract

PURPOSE: A composite sheet is provided to improve and maintain contact reliability, and to improve productivity of the sheet by reducing compression cycle while increasing a lifetime of the film efficiently. CONSTITUTION: A composite sheet(32) includes a heat-resistant resin film and a sheet consisting of silicon rubber-based composition formed on either sides of the heat-resistant resin film. The silicon rubber-based composition includes silica powder of 2~100, carbon black of 0~200, magnesium oxide of 10~1000, ferric oxide of 0~20, and ceria of 0.1~0.5 based on the silicon rubber of 100. The heat-resistant resin film is comprised of one among polyimide resin, aromatic polyamide resin, polyether ether keton resin, polyethersulfone resin, and polyphenylene sulfide resin.

Description

Composite Sheet {Complex Sheet}

The present invention is a crimping step that is one of the processes for producing electronic devices, in particular flat panel displays (FPDs), and more particularly color TFT liquid crystal modules, color STN liquid crystal module plasma display panels (PDPs), and organic electroluminescent display panels. It relates to a composite sheet used for.

Conventionally, in the manufacturing process of an electronic device, the crimping process as shown in FIGS. 1-3 is performed. 1 is an overall view, FIG. 2 is an enlarged view of the portion A of FIG. 1 as viewed from the direction of the arrow X, and FIG. 3 is an enlarged view of the portion B of FIG. . However, FIG. 1 has shown the state after crimping before FIG. 2 and FIG.

Reference numeral 1 in the figure denotes a glass substrate on which the first electrode 2 is formed. One end of the flexible printed circuit board (FPC) 3 is laminated on the end of the glass substrate 1 by thermocompression bonding. Here, the FPC 3 has the film 5 in which the driver IC 4 was formed, and the 2nd electrode 6 formed in the one side of this film 5. The heater 8 provided with the release sheet 7 in the lower end part is arrange | positioned on the thermocompression scheduled part of the said glass substrate 1 and the FPC3. The other end of the FPC 3 is laminated by thermal compression with a printed circuit board (PCB) substrate 10 having a third electrode 9 formed at the end thereof. The heater 12 provided with the release sheet 11 in the lower end part is arrange | positioned on the thermocompression scheduled part of the said PCB board | substrate 10 and the FPC3. Reference numeral 13 denotes an anisotropic conductive film (ACF), and reference numeral 14 denotes a sealing material. Further, the thickness is set thinner in the order of the third electrode 9, the second electrode 6, and the first electrode 2.

In the crimping step of FIG. 1, the FPC on the ACF 13 is placed between the first electrode 2 of the glass substrate 1 and the second electrode 6 of the FPC 3 with the ACF 13 interposed therebetween. The first electrode 2 of the glass substrate 1 and the second electrode 6 of the FPC 3 are formed by sandwiching the release sheet 7 between the 3 and the heater 8 by thermocompression bonding with the heater 8. Electrical connection with the Further, the FPC 3 and the heater (on the ACF 13) are interposed between the third electrode 9 of the PCB substrate 10 and the second electrode 6 of the FPC 3. By interleaving the release sheet 11 between the 12 and thermocompression by the heater 12, the third electrode 9 of the PCB substrate 10 and the second electrode 6 of the FPC 3 The connection is made.

However, the release sheets 7 and 11 used in the crimping step are required to have releasability to the ACF 13 pushed out at the time of the crimping together with the cushioning property for uniform crimping. In particular, in the part (part B) which connects the 3rd electrode 9 of a PCB board | substrate and the 2nd electrode 6 of the FPC 3, cushioning property larger than the release sheet for glass substrates is calculated | required. DESCRIPTION OF RELATED ART Conventionally, the silicone rubber sheet, the fluororesin film which has mold release property, or the composite sheet of a silicone rubber and a fluororesin film, etc. are variously proposed and used.

Conventionally, for example, Japanese Patent Application Laid-Open No. 2004-55687 has been proposed as a rubber composite sheet having the same purpose as the release sheet. The rubber composite sheet is composed of a resin film, a fluororesin layer formed on one side (flexible substrate side) of the resin film, and a rubber layer formed on the other side of the resin film, and is resistant to deformation and an anisotropic conductive film; It has a structure to secure the release property of.

However, in recent years, in order to shorten a crimping cycle and improve productivity, the material of ACF is replaced by the low temperature short time type, and maintaining and improving connection reliability is calculated | required. Moreover, it is difficult to say that the crimping process using ACF also has many aspects for a use purpose, and it is difficult to say that the proposed release sheet provides satisfactory release characteristics and repeated service life.

An object of the present invention is to provide a structure comprising a sheet made of a heat-resistant resin film and a silicone rubber composition formed on both surfaces of the film, and to make a specific composition of the silicone rubber composition of the sheet to form various anisotropic conductive films. SUMMARY OF THE INVENTION An object of the present invention is to provide a composite sheet having a long repeated service life and having good release properties suitable for the pressing process to be used.

The composite sheet of this invention is a composite sheet used in the thermocompression bonding process which is one of the manufacturing processes of an electronic device, Comprising: The sheet which consists of a heat resistant resin film and the silicone rubber composition formed on both surfaces of this heat resistant resin film, The said The silicone rubber composition of the sheet is, by weight part, silica powder: 2 to 100, carbon black: 0 to 200, magnesium oxide: 10 to 1000, iron oxide: 0 to 20, and cerium oxide: 0.1 to 0.5 with respect to the silicone rubber 100. It is characterized by including.

In this invention, although the said heat resistant resin film is a film which consists of a heat resistant resin in any one of a polyimide resin, an aromatic polyamide resin, a polyether ether ketone resin, a polyether sulfone resin, and a polyphenylene sulfide resin, It is not specifically limited.

In this invention, it is for the following reason that a silica powder shall be 2-100 weight part with respect to 100 weight part of silicone rubber. That is, when silica powder is less than 2 weight part, rubber hardness will become low and residual compressive distortion will increase. Moreover, when silica powder exceeds 100 weight part, rubber hardness will become high too much and a cushion property will fall, and moldability will deteriorate.

In the present invention, the carbon black is 0 to 200 parts by weight based on 100 parts by weight of the silicone rubber. When the carbon black is more than 200 parts by weight, the electrical conductivity is not increased and the antistatic property is less improved and the moldability is improved. Because it worsens.

In this invention, it is for the following reason that magnesium oxide is 10-1000 weight part with respect to 100 weight part of silicone rubber. That is, when magnesium oxide is less than 10 weight part, heat conduction rate is low and temperature rising takes time. In addition, when magnesium oxide exceeds 1000 parts by weight, the thermal conduction rate does not increase, the effect on the increase of the filling amount cannot be obtained, and the moldability deteriorates and the rubber after curing becomes brittle.

In the present invention, when the iron oxide is 0 to 20 parts by weight with respect to 100 parts by weight of the silicone rubber, when it exceeds 20 parts by weight, the low molecular weight of the silicone polymer under high temperature pressurization cannot be suppressed, and the residual compression distortion cannot be reduced. Because.

In the present invention, the cerium oxide is 0.1 to 0.5 parts by weight based on 100 parts by weight of the silicone rubber for the following reason. That is, when cerium oxide is less than 0.1 weight part, the low molecular weight of a silicone polymer under high temperature pressurization will generate | occur | produce, and residual compression distortion will be large. Moreover, when cerium oxide exceeds 0.5 weight part, the low molecular weight formation of a silicone polymer under high temperature pressurization cannot be suppressed, and residual compression distortion cannot be reduced.

In the present invention, the total thickness is preferably 0.01 to 5 mm. Here, when the total thickness is less than 0.01 mm, the service life is not satisfied due to lack of strength, and when the total thickness is more than 5 mm, the thermal conduction rate is low, so that the crimping takes time.

According to the present invention, it is possible to obtain a composite sheet having a long repeating service life and good release properties suitable for a crimping step using various anisotropic conductive films.

EMBODIMENT OF THE INVENTION Hereinafter, the composite sheet which concerns on each embodiment of this invention is demonstrated with reference to drawings. Moreover, following 1st-8 embodiment is a composite sheet used for crimping | bonding between electrodes in the A part of FIG. Moreover, following 9th and 10th embodiment are related with the composite sheet used for crimping | bonding between electrodes in the B part of FIG.

(1st embodiment)

See FIG. 4.

The code | symbol 21 in FIG. Shows the heat resistant resin film (polyimide film) of 50 micrometers in thickness which consists of polyimides. The uneven surfaces 21a and 21b roughened by the corona discharge treatment are formed on both surfaces of the polyimide film 21, respectively. The black sheets 22a and 22b made of the silicone rubber composition are formed on both surfaces of the polyimide film 21 on which the uneven surfaces 21a and 21b are formed. Here, the sheets 22a and 22b include 100 parts by weight of organopolysiloxane (silicone rubber), 12 parts by weight of silica powder, 42 parts by weight of carbon black, 260 parts by weight of magnesium oxide, 2 parts by weight of iron oxide, and 0.1 parts by weight of cerium oxide. It forms by laminating | stacking, drying, and hardening | curing the silicone type composition which mixes uniformly.

Next, the manufacturing method of the composite sheet of FIG. 4 is demonstrated.

(1) First, a 50-micrometer-thick polyimide film was used as a base material. This polyimide film was coated on both surfaces using a polyalkoxysilane, a platinum compound and a tetraethoxysilane dissolved in n-nucleic acid as a primer, and dried at room temperature for 10 minutes. The adhesion amount at this time was 2.0g / m <2> of single side | surfaces. In addition, apart from this, silicon is obtained by uniformly mixing 100 parts by weight of the organopolysiloxane with 12 parts by weight of silica powder, 42 parts by weight of carbon black, 260 parts by weight of magnesium oxide, 2 parts by weight of iron oxide, and 0.1 parts by weight of cerium oxide. A rubber composition was obtained.

(2) Next, the said silicone type rubber composition was melt | dissolved in the toluene solvent, and also the platinum vulcanizing agent was added and the rubber paste was created. Subsequently, after coating the said rubber paste on the single side | surface of the 50-micrometer-thick polyimide film which carried out the said primer process, it vulcanized for 10 minutes by 170 degreeC with a hot air vulcanization furnace. Subsequently, this process was repeated to the other surface of the polyimide film, and the upper and lower surfaces were made into the symmetrical structure by making the core material of polyimide into the middle. Furthermore, secondary vulcanization was carried out by treatment in a hot air drying furnace at 200 ° C. for 4 hours to obtain a composite sheet of silicone rubber composition coating having a total thickness of 200 μm.

According to 1st Embodiment, the sheet | seats 22a and 22b which consist of the polyimide film 21 which has uneven surface 21a, 21b, and the silicone rubber composition which has predetermined composition formed in both surfaces of this polyimide film 21. ), A composite sheet 23 is formed. Therefore, the composite sheet 23 of this invention has a long repeat service life suitable for the crimping | compression-bonding process using various anisotropic conductive films, and has favorable mold release characteristics.

In fact, the test of the thickness reduction rate (%) of the said composite sheet was done using the tester shown in FIG. This test mounts the composite sheet 32 on the heater lower half 31, presses the composite sheet 32 to the heated heater upper panel 33, and measures the rate of thickness reduction of the composite sheet 32. I did it by doing. Moreover, the crimp durability test of the said composite sheet was done using the tester as shown in FIG. In this test, the composite sheet 32 is placed on the heated heater lower half 31 by sequentially inserting the printed board 34a, the anisotropic conductive film 35, and the copper-deposited polyimide film 34b without pattern design. The composite sheet 32 was pressed by pressing the heated upper half 33.

Thickness reduction rate was calculated | required as press pressure: 4 MPa, heater upper half temperature: 300 degreeC, heater lower half temperature: normal temperature, press holding time: 10 sec, press interval: 5 sec, and press number: 80 times.

Press durability: press pressure: 3 MPa, heater upper temperature: 280 ° C, heater lower half temperature: 45 ° C, press holding time: 15 sec, press count: 20, 40, 60, 80 times (pressing the ACF after each press Confirmed by conduction after the crimping test).

(Embodiments 2 and 8 and Comparative Examples 1 to 3)

The composite sheet was obtained by operation similar to the said 1st Embodiment except changing the compounding ratio of the component of the composition of a raw material. However, about the comparative example 3, the polyimide film is not used.

Table 1 shows the components of the compositions of the raw materials of the first embodiment 1 to 8 and Comparative Examples 1 to 3, thickness reduction rate, temperature increase rate, antistatic properties, molding processability and crimp durability (20 times, 40 times, 60 times, respectively). , 80 times). However, in Table 1, the temperature increase rate, antistatic property, molding workability, and crimp durability indicated that the best one was a double ply circle, the good one was a single ply circle, the triangular one was triangular, and the bad was indicated by x. In addition, in Table 1, the thickness of the sheets 22a and 22b of Examples 1-8 and Comparative Examples 1 and 2 is 75 micrometers, respectively, and the thickness of the rubber layer of Comparative Example 3 is 200 micrometers.

 Raw material  Compounding ratio (parts by weight) Embodiment Comparative example 1 2 3 4 5 6 ７ ８ One 2 3 Silicone rubber 100 100 100 100 100 100 100 100 100  100 100 Silica powder 2-100 12 5 2 2 5 20 30 100 2 150 10 Carbon black 10-200 42 10 70 60 55 25 10 200 5 250 40 Magnesium oxide 10-1000 260 30 10 50 120 500 700 1000 10 1500 250 Iron oxide 0-20 2 0 One One One 4 6 20 0 30 2 Cerium oxide 0.1-0.5 0.1 0.1 0.3 0.3 0.3 0.3 0.3 0.5 0.05 One 0.3 Thickness reduction rate 0.5 1.3 1.3 1.1 0.9 0.8 1.3 0.3 1.4 1.4 2.2 Temperature rise rate ◎ △ × △ ○ ◎ ◎ ◎ × × ◎ Antistatic ◎ △ ◎ ◎ ◎ ◎ △ ◎ × × ◎ Moldability ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ Crimping Durability (Number) 20 ○ ○ ○ ○ ○ ○ ○ ○ － × 40 ○ × ○ ○ ○ ○ ○ × － 60 ○ × × ○ ○ ○ － 80 ○ × ○ ○ －

However, in the temperature increase rate, ◎: high thermal conductivity and very short compression time, ○: medium heat conductivity and good compression time, △: low thermal conductivity and good compression time, x: weak thermal conductivity And insufficient shortening of the compression time.

In the antistatic property,?: Highly conductive and very good antistatic,?: Moderately conductive, satisfactory antistatic,?: Low conductive, antistatic, x: weakly conductive, and exhibit antistatic failure, respectively.

In molding processability, (circle): Molding favorable.

In crimping durability, (circle): good conduction and x: poor conduction.

The consideration about the composite sheet of 1st Embodiment 1-8 and Comparative Examples 1-3 based on the said Table 1 is as follows.

In the case of the first embodiment, it was confirmed that the temperature increase rate, antistatic property, molding processability, and crimp durability as properties are well-balanced, and satisfy the characteristics required for the thermocompression sheet used for crimping the ACF.

In the case of the second embodiment, the temperature increase rate is low thermal conductivity, shortens the crimping time, and has antistatic property, but prevents electrification. However, the strength fall of the coating layer which consists of silicone rubber compositions was seen, and it was confirmed that the crimp durability was insufficient.

In the third embodiment, the rate of temperature rise is weak heat conduction, the shortening of the crimping time is insufficient, and the antistatic property is good at high electric conductivity. In addition, a slight decrease in strength was observed in the coating layer made of the silicone rubber composition, and it was confirmed that the compression durability was insufficient.

In the case of the fourth embodiment, the temperature increase rate is low thermal conductivity, shortens the crimping time, and the antistatic property is very good at high electric conductivity. However, it was confirmed that a slight decrease in strength was observed in the coating layer made of the silicone rubber composition, and the crimping durability was also insufficient.

In the case of the fifth embodiment, the temperature increase rate is medium heat conduction, the compression time is shortened favorably, and the antistatic property is very good as the high electric warfare. However, a slight drop in strength was observed in the coating layer made of the silicone rubber composition, and it was confirmed that the compression durability was also slightly deficient.

In the case of the sixth embodiment, the temperature increase rate is medium heat conduction and the compression time is shortened very satisfactorily, and the antistatic property is low conductivity but prevents charging. Moreover, it was confirmed that strength fall was not seen in the coating layer which consists of silicone rubber compositions, and crimp durability was also enough.

In the case of the seventh embodiment, the temperature increase rate is high thermal conductivity, the compression time is shortened very satisfactorily, and the antistatic property is low. Moreover, it was confirmed that strength fall was not seen in the coating layer which consists of silicone rubber compositions, and crimp durability was also enough.

In the case of the eighth embodiment, the temperature increase rate is high thermal conductivity, the compression time is shortened very satisfactorily, and the antistatic property is very good in high conductivity. However, the strength fall is seen in the coating layer which consists of a silicone rubber composition, and crimp durability is also inadequate. In addition, although the moldability was not impaired, it was confirmed that the composite sheet lacked flexibility due to the large amount of component blending, and the uncertainty remained in the pressing of the healthy ACF.

In the case of the comparative example 1, since the temperature increase rate is weak heat conduction, shortening of a crimping time is inadequate, and antistatic property is weak electroconductivity, it is an antistatic failure. Moreover, since the strength of the coating layer which consists of a silicone rubber composition falls remarkably, it was confirmed that deformation amount is large and it is impossible to repeat crimping.

In the case of the comparative example 2, it was confirmed that a component compounding quantity was large and molding impossibility as molding processability.

In the case of the comparative example 3, the temperature increase rate is high thermal conductivity, the crimping time is shortened very well, and the antistatic property is extremely good as a high electric conductivity. However, since the strength of the coating layer which consists of a silicone rubber composition falls remarkably, it was confirmed that deformation amount is large and it is impossible to repeat crimping.

(Ninth embodiment)

See FIG. 7. In addition, in the composite sheet of 9th Embodiment and 10th Embodiment mentioned later, since the unevenness | corrugation of the terminal part of an FPC is assumed to be used for a large use, the thickness of a 1st, 2nd sheet is formed thick enough, have. 7, the composite sheet is set so that the first sheet 42a is on the ACF side and the second sheet 42b is on the heater side.

Reference numeral 41 in the figure denotes a heat resistant resin film (polyimide film) having a thickness of 25 μm made of polyimide. On both surfaces of the polyimide film 41, uneven surfaces 41a and 41b each having a roughness 1.4 of surface roughness Ra roughened by corona discharge treatment are formed. On both surfaces of the polyimide film 41 having the uneven surfaces 41a and 41b formed thereon, a first black sheet (210 µm thick) 42a made of a silicone rubber composition and a gray second sheet made of a silicone rubber composition ( 115 micrometers thick) 42b is formed.

Here, the first sheet 42a has 12 parts by weight of silica powder, 42 parts by weight of carbon black, 262 parts by weight of magnesium oxide, 2 parts by weight of iron oxide, and oxidation in 100 parts by weight of organopolysiloxane (silicone rubber) having an average degree of polymerization of 4000. It forms by laminating | stacking, drying, and hardening | curing the silicone type composition which mixes 0.1 weight part of cerium uniformly. The second sheet 42b is formed by uniformly mixing 31 parts by weight of silica powder, 698 parts by weight of magnesium oxide, 6 parts by weight of iron oxide, and 0.1 parts by weight of cerium oxide in 100 parts by weight of organopolysiloxane (silicone rubber) having an average degree of polymerization of 3700. It is formed by laminating, drying and curing the silicone composition. Table 2 below shows the blending ratios of the raw materials, the thicknesses of the first and second sheets, the thickness reduction rate, the temperature increase rate, the antistatic property, the molding processability, and the pressing durability in the ninth embodiment and the tenth embodiment described later. 20, 40, 60, and 80 times the results of the investigation are shown. However, in Table 2, the temperature increase rate, antistatic property, molding workability, and crimp durability indicated the best one in two-ply circles, the good one in one-ply circle, the triangular one, and the poor one in x.

Raw material  9th Embodiment (1st sheet / 2nd sheet)  Tenth Embodiment (First Sheet / Second Sheet) Silicone rubber 100/100 100/100 Silica powder 12/31 12/12 Carbon black 42/0 42/42 Magnesium oxide 262/698 262/262 Iron oxide 2/6 2/2 Cerium oxide 0.1 / 0.1 0.1 / 0.1 Thickness (㎛) 210/115 150/150 Thickness reduction rate 0.6 0.4 Temperature rise rate ◎ ◎ Antistatic ○ ◎ Moldability ○ ○ Crimping Durability (Number) 20 ○ ○ 40 ○ ○ 60 ○ ○ 80 ○ ○

However, in the temperature increase rate, ◎: high thermal conductivity and very good compression time

The case where it can shorten is shown.

In antistatic property,?: Highly conductive and very good antistatic,

(Circle): It is moderate electroconductivity and shows good antistatic, respectively.

In molding processability, (circle): Molding favorable.

In crimping durability, (circle): Good conduction is shown.

Next, the manufacturing method of the composite sheet 43 of FIG. 7 is demonstrated.

(1) First, a 25-micrometer-thick polyimide film was used as the substrate. Further, a silicone rubber-based composition was obtained by uniformly mixing 12 parts by weight of silica powder, 42 parts by weight of carbon black, 262 parts by weight of magnesium oxide, 2 parts by weight of iron oxide, and 0.1 parts by weight of cerium oxide by a kneader with 100 parts by weight of the organopolysiloxane.

(2) Next, the said silicone type rubber composition was melt | dissolved in the toluene solvent, and also the platinum vulcanizing agent was added and the rubber paste was created. Subsequently, after coating the said rubber paste on the single side | surface of the 25-micrometer-thick polyimide film which carried out the said primer process, it vulcanized for 10 minutes by 170 degreeC with a hot air vulcanization furnace. Subsequently, this process was repeated to the other surface of the polyimide film, and it was set as the double-sided structure which made the core material of polyimide the middle. Furthermore, secondary vulcanization was carried out by treatment in a hot air drying furnace at 200 ° C. for 4 hours to obtain a composite sheet 43 of a silicone rubber composition coating having a total thickness of 350 μm.

According to the ninth embodiment, the thickness of the polyimide film 41 having the uneven surfaces 41a and 41b and the silicone rubber composition having a predetermined composition formed on one surface of the polyimide film 41 are each 210. The composite sheet 43 is formed from the second sheet 42b each having a thickness of 115 µm, which is formed of a silicone rubber-based composition having a predetermined composition, formed on the first sheet 42a having a thickness and the other side of the polyimide film 41. Is composed. Therefore, the composite sheet 43 of the present invention not only obtains the same effects as in the first embodiment, but also has the following effects.

That is, the degree of cushioning required for the composite sheet varies depending on the use. For example, for applications that require cushioning, the thickness of the sheet needs to be thickened. If the thickness of the first and second sheets on both sides is thickened, cushioning can be imparted, but thermal conductivity is impaired. do. Therefore, by thickening the thickness of the first sheet 42a in contact with the work (flexible substrate) and making the thickness of the second sheet 42b thin, cushioning properties can be imparted without impairing thermal conductivity. In the case of the ninth embodiment, since the thickness of the first sheet 42a is set to 210 µm and the thickness of the second sheet 42b is set to 115 µm, the thermal conductivity of the composite sheet 43 is not impaired. Cushioning property can be provided. In addition, in the composite sheet 43 of FIG. 5, the 1st sheet 42a is necessary for the functional expression, and the 2nd sheet 42b is necessary for the bending prevention.

In addition, when sheets of the same color are formed on both sides of the polyimide film, it is impossible to visually identify the front and back (face and inside) of the composite sheet 43. Therefore, in the ninth embodiment, since the color of the first sheet 42a is made black and the color of the second sheet 42b is made gray, the front and back of the composite sheet 43 can be easily identified. I can do it. Moreover, since the thickness of a polyimide film is 25 micrometers, compared with 1st Embodiment, thermal conductivity can be improved.

Thus, the composite sheet of 9th Embodiment improves a temperature increase rate, is set in the balance of antistatic property, molding processability, and crimp durability, and is suitable also for the use which requires cushion property compared with 1st Embodiment.

(10th embodiment)

See FIG. 8. However, the same members as in Fig. 7 are denoted by the same reference numerals and the description thereof is omitted.

As shown in Table 2, the first sheet 52a is black with a thickness of 150 µm, and the second sheet 52b has the same thickness and color as the first sheet 52a. Therefore, the compounding ratio of the 1st sheet 51a and the 2nd sheet 52b is the same. In addition, the manufacturing method of the composite sheet 53 which concerns on 10th Embodiment is the same as that of the ninth embodiment.

According to the tenth embodiment, a composite sheet can be obtained in which the temperature increase rate is improved, the antistatic property, the molding processability and the compression durability are set in a good balance, and the thickness reduction rate and the thermal conductivity are slightly improved as compared with the first embodiment.

FIG. 1 is an explanatory diagram in the case where thermocompression bonding between an electrode terminal portion of a circuit board, a glass substrate, and a conductive portion of a PCB substrate is performed using a release sheet.

FIG. 2 is a view seen from the direction of the X arrow in which the main portion of FIG. 1 is enlarged. FIG.

FIG. 3 is a view seen from the direction of the arrow Y, in which the main portion of FIG. 1 is enlarged. FIG.

4 is a schematic cross-sectional view of the composite sheet according to the first embodiment of the present invention.

5 is an explanatory view of a test apparatus for testing the thickness reduction rate of the composite sheet of the present invention.

6 is an explanatory diagram of a test apparatus for testing the crimp durability of the composite sheet of the present invention.

7 is a schematic cross-sectional view of a composite sheet according to a ninth embodiment of the present invention.

8 is a schematic cross-sectional view of a composite sheet according to a tenth embodiment of the present invention.

Claims (3)

In the composite sheet used in the thermocompression bonding step which is one of the manufacturing processes of the electronic device, And a sheet made of a heat resistant resin film and a silicone rubber composition formed on both sides of the heat resistant resin film, The silicone rubber composition of the sheet is, by weight part, silica powder: 2 to 100, carbon black: 0 to 200, magnesium oxide: 10 to 1000, iron oxide: 0 to 20, cerium oxide: 0.1 to 0.5 with respect to the silicone rubber 100. Composite sheet comprising a. The method of claim 1, The said heat resistant resin film consists of a heat resistant resin in any one of polyimide resin, aromatic polyamide resin, polyether ether ketone resin, polyether sulfone resin, and polyphenylene sulfide resin. The method according to claim 1 or 2, A composite sheet having a total thickness of 0.01 to 5 mm.

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