KR20070075356A - Laminate for cof, cof film carrier tape and electronic device - Google Patents

Abstract

A laminate for COF(chip on film) is provided to inhibit dimensional change or deformation of film carrier tapes by heat during an Au-Sn step in a COF manufacture process and improve electric connection reliance of electronic parts and film carrier tapes. The laminate for COF has conductors(20) on one surface or both surfaces of an insulating layer(10). The insulating layer(10) is a multi-layered structure composed of at least two polyimide-based resins. The insulating layer(10) has a glass transition temperature of 350°C or higher and a thermal expansion coefficient of 70ppm/°C or less at 300-350°C. The COF film carrier tape is obtained by processing the laminate for COF.

Description

COP Laminated Plate, COF Film Carrier Tape and Electronic Device {LAMINATE FOR COF, COF FILM CARRIER TAPE AND ELECTRONIC DEVICE}

1 is a cross-sectional view of a laminate for COF,

2 is a conceptual diagram illustrating an example of mounting an IC chip on a carrier tape.

<Description of Symbols for Major Parts of Drawings>

1: IC chip 2: bump

3, 10: insulation layer 4: circuit

20: conductor 11, 13 thermoplastic polyimide layer

12: non-thermoplastic polyimide layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate for a chip on film (COF) for mounting electronic components such as IC (Integrated Circuit) or LSI (Large Integrated Circuit), and a COF film carrier tape and an electronic device obtained by processing the same.

BACKGROUND With the spread and development of electronic devices such as cameras, personal computers, mobile phones, and liquid crystal displays, the demand for printed wiring boards for mounting electronic components such as ICs or LSIs is increasing rapidly. BACKGROUND ART In recent years, a mounting method using a film carrier tape for mounting an electronic component that can be mounted in a small space is required, which requires miniaturization, light weight, thinness, fixed colorization, and high functionality of an electronic device.

TAB tape and T-BGA tape exist in the film carrier tape for electronic component mounting, but COF is put into practical use as a mounting method which mounts a smaller space and a higher density.

COF is a composite component in which a raw semiconductor IC is directly mounted on a film-like wiring board. In most cases, COF is used in connection with a larger rigid wiring board or display board. And the film-form wiring board is made from the laminated board which laminated | stacked organic polymer films, such as polyimide, and metal foil.

The film-like wiring board laminates the photosensitive resin layer on the metal foil surface of the metal foil laminate, performs exposure corresponding to the desired wiring pattern, photocures the necessary portion of the photosensitive resin, and removes the photosensitive resin of the unexposed portion by development. The coating metal layer of the substrate which is not covered with the cured resist is removed by etching, or the plating metal is deposited on the part which is not covered with the cured resist by plating. Finally, the method of removing a hardening resist by peeling and obtaining the wiring board which has a desired semiconductor pattern is employ | adopted. As a method of laminating | stacking photosensitive resin, there exist a method of apply | coating a liquid resist, drying, and the method of laminating a photosensitive resin laminated body.

As a laminated board for COF, the polyimide copper clad laminated board obtained by sputtering copper to a polyimide resin film mainly has been used. In the case of a sputtering system, since the yield tends to worsen by the pinhole of a metal layer, the polyimide metal laminated board without a pinhole is desired. As a metal laminated plate without a pinhole, there exist some which laminated | stacked stainless foil, rolled copper foil, electrolytic copper foil, and polyimide. Although a laminated board is obtained by laminating | stacking a polyimide on copper foil by casting or a lamination method, in order to improve adhesive force etc., a thermoplastic polyimide layer may be formed on metal foil.

On the other hand, IC chip mounting is carried out at a low temperature such as ACF, NCP, ultrasonic bonding, or at a high temperature of 300 ° C. or higher such as Au-Au bonding or Au-Sn bonding. Many Au-Au junctions and Au-Sn junctions are employed in terms of connection reliability between the wiring and the wiring.

In the case of the polyimide laminate obtained by the sputtering method, since there is no thermoplastic resin layer, the phenomenon that the metal wiring penetrates into the polyimide layer during chip mounting of 300 ° C. or higher does not occur, but the adhesiveness with the metal wiring is inferior or the above problems. There is.

When laminating | stacking a polyimide layer to copper foil by coating, crimping | bonding, etc., in order to raise the adhesive force between copper foil and a polyimide layer, and to provide heat resistance, it is generally necessary to use thermoplastic polyimide, but IC of 300 degreeC or more is used. When the chip is mounted, there is a problem in that bumps between the metal wiring and the IC chip occur, the wiring penetrates into the thermoplastic polyimide layer, and underfill does not enter. Even if the polyimide layer is thermally deformed, the wiring and the IC chip bumps may be misaligned, and the wiring and the IC chip bumps may not be joined, or short circuits may occur due to contact with adjacent wiring. do. In addition, since the wiring penetrates into the thermoplastic polyimide layer and the polyimide layer greatly deforms, the gap between the IC chip and the polyimide becomes narrow, or a point where stress is concentrated occurs. Occurs, and problems such as peeling of the wiring from the polyimide layer occur.

[Patent Document 1] Japanese Patent No. 2574535

[Patent Document 2] Japanese Patent Publication No. 2003-340961

In patent document 1, the copper polyimide board | substrate which performed copper electroless plating on the polyimide surface and heat-processed 120-420 degreeC as needed, The polyimide resin is 120-420 degreeC. Although the manufacturing method of the copper polyimide board | substrate which improved the curvature which has a thermal expansion coefficient of 15-20 ppm / degree in the range is described, since it is a sputter | spatter system, the yield tends to worsen by the pinhole of a metal layer, and the adhesiveness of a conductor and a polyimide layer Since this is low, there existed a problem of metal wiring peeling from a polyimide layer at the time of IC chip mounting.

In patent document 2, although the polyimide metal laminated board whose humidity expansion coefficient of a polyimide layer is less than 0-10% RH, and whose thermal expansion coefficient is 10-25 ppm / degreeC is described, polyimide at the time of IC chip mounting of 300 degreeC or more is described. There was a problem that the layer was greatly deformed, misalignment occurred between the wiring and the bumps of the IC chip, the metal wiring penetrated into the thermoplastic polyimide layer, and the underfill did not enter.

As described above, it is disclosed that the coefficient of thermal expansion of the polyimide is less than or equal to the predetermined range and the temperature of the deformation temperature is greater than or equal to the predetermined range, but flip chip mounting using the Au-Sn process (eutectic crystal) in the COF manufacturing process is disclosed. In the case of, the polyimide layer is thermally deformed because it is exposed to high temperature and high pressure of 300 ° C. or higher, causing misalignment between the bumps of the metal wiring and the IC chip, peeling of the metal wiring and the polyimide layer, or wiring. There was a problem of intrusion.

The present invention is excellent in dimensional stability and adhesion to metal wiring, and during the Au-Sn process in the COF manufacturing process, the film carrier tape suppresses the dimensional change and deformation caused by heat, and the metal wiring and the IC chip The reliability of the connection between the electronic component and the film carrier tape, which is suitable for underfill filling, does not cause a problem that a bump occurs, a problem that the wiring penetrates into the thermoplastic polyimide layer, or a problem that the wiring is peeled from the polyimide layer. An object of the present invention is to provide a laminate for COF, a COF film carrier tape, and an electronic device that can be improved.

The present invention is a laminate for COF having a conductor on one or both sides of the insulating layer, wherein the insulating layer is a multilayer structure made of two or more polyimide resins, and the glass transition temperature of the insulating layer is 350 ° C or higher and 300 The thermal expansion coefficient of -350 degreeC is 70 ppm / degrees C or less, The laminated sheet for COF characterized by the above-mentioned. Moreover, this invention is COF film carrier tape obtained by processing the said laminated board for COF. The present invention is also an electronic device in which an electronic component is mounted on a wiring board obtained by circuit processing the laminate for COF.

In the said laminated board for COF, a favorable COF laminated board is provided by satisfying any one or more of the following.

1) The insulating layer has a thermoplastic polyimide layer on one side or both sides of a non-thermoplastic polyimide layer, and z calculated by the following formula (1) is 20 or less.

z = α × x-β × y (1)

only,

α: 300 to 350 ° C. thermal expansion coefficient (ppm / ° C.) of the thermoplastic polyimide layer

x: ratio of thermoplastic polyimide layer thickness to total thickness of insulating layer

β: 300 to 350 ° C. thermal expansion coefficient (ppm / ° C.) of the non-thermoplastic polyimide layer

y: The ratio of the thickness of a non-thermoplastic polyimide layer to the total thickness of an insulating layer.

2) The surface roughness (Rz) of the surface of the conductor directly in contact with the insulating layer is 1.0 µm or less.

3) The insulating layer is obtained by directly applying a precursor solution of polyimide to a conductor and imid-converting it.

The present invention is also an electronic device in which an electronic component is mounted on a wiring board obtained by circuit processing the laminate for COF, but the electronic device can be manufactured by the following method. That is, the conductive layer has a conductor on one or both sides of the insulating layer, and the insulating layer has a multilayer structure made of two or more polyimide resins, and the glass transition temperature of the insulating layer is 350 ° C or higher and the coefficient of thermal expansion of 300 to 350 ° C. A method for manufacturing an electronic device, in which an electronic component is mounted, wherein a laminate having a thickness of 70 ppm or less is prepared, the conductor of the laminate is processed into an arbitrary circuit pattern, and then the electronic component is mounted on the circuit processed chuck layer substrate at 300 ° C. or higher. to be. Here, it is more preferable that the laminated sheet meets the preferable requirements of the laminated laminate for COF of 1) to 3).

The present invention will be described in detail below.

The laminated sheet for COF is comprised from the metal foil and the insulating layer which consist of a conductor, and the metal foil may exist only in the single side | surface of an insulating layer, or may be in both surfaces. The insulating layer has a multilayer structure of two or more layers, and each layer is made of polyimide resin. The insulating layer preferably has at least one non-thermoplastic polyimide layer and at least one thermoplastic polyimide layer, and at least one thermoplastic polyimide layer is in contact with the metal foil. The preferable thickness range of the insulating layer in this invention is the range of 35-55 micrometers.

The material of the metal foil to be used is irrelevant. For example, stainless steel, copper, iron, aluminum and the like are exemplified, but copper or copper alloy is excellent. The metal foil may be subjected to surface treatment by zinc plating, nickel plating, a silane coupling agent, or the like. Although there is no restriction | limiting in the thickness of metal foil, According to the fine pitch of metal wiring, the range of 5-50 micrometers is preferable, and the range of 5-25 micrometers is more preferable. Moreover, in order to improve the transparency of polyimide and to improve IC chip mountability, it is preferable that the surface roughness Rz of the copper foil surface which contact | connects an insulating layer is 1.0 micrometer or less.

The glass transition temperature (Tg) of an insulating layer is 350 degreeC or more, Preferably it is the range of 350 degreeC-450 degreeC. Here, the glass transition temperature of the insulating layer can be measured by a dynamic viscoelasticity measuring device. Specifically, it measures on the conditions shown in an Example.

In addition, the insulating layer needs to have a thermal expansion coefficient of 300 to 350 ° C. (an average value of the thermal expansion coefficient measured in the range of 300 to 350 ° C.) to be 70 ppm / ° C. or less, and preferably 0 to 50 ppm / ° C. or less. Hereinafter, this 300-350 degreeC thermal expansion coefficient is also only called thermal expansion coefficient.

When the insulating layer has a multilayer structure having at least one non-thermoplastic polyimide layer and at least one thermoplastic polyimide layer, the preferred structure of the insulating layer is adjacent to one or both sides of the non-thermoplastic polyimide layer. It is preferable that it is the multilayer structure of the two layers or three layers which provided the polyimide layer, and at least 1 layer of thermoplastic polyimide layer is in contact with metal foil. In the present invention, the thermoplastic polyimide means that the coefficient of linear expansion greatly changes at a temperature higher than Tg, specifically, that the coefficient of linear expansion varies by 100 ppm / ° C or more at a temperature higher than Tg.

And as for an insulating layer, it is preferable to set the value of z calculated by the said Formula (1) to 20 or less, and it is more preferable to set it to 10 or less. For example, in Formula (1), when (alpha) is 50 ppm / degreeC, (beta) is 30 ppm / degreeC, thermoplastic polyimide layer thickness is 10 micrometers, and non-thermoplastic polyimide layer thickness is 30 micrometers, an insulation layer thickness is 40 micrometers. Since x is calculated as 0.25 and y is 0.75, z = 50 x 0.25-30 x 0.75 = -10.0. Although it is preferable to make the value of z into 20 or less, it is more preferable to exist in the range of 20--20. By setting the range of z to this range, wave distortion under the chip at the time of chip mounting is suppressed, and generation | occurrence | production of the void which arises when the underfill is filled is also suppressed. In addition, Formula (1) is more effective when (alpha)> (beta) and x <y.

Although there is no restriction | limiting in particular about the thickness of a non-thermoplastic polyimide layer and a thermoplastic polyimide layer, It is preferable to satisfy the said requirement and to make thickness of a non-thermoplastic polyimide layer into the range of 2-100 micrometers. The more preferable thickness range of a non-thermoplastic polyimide layer is the range of 5-50 micrometers. The preferable thickness range of a thermoplastic polyimide layer is 0.5-10 micrometers, More preferably, it is the range of 1-5 micrometers, It is good that it is the range of 1 / 20-1 / 2 of the thickness of a non-thermoplastic polyimide layer.

The polyimide which becomes the polyimide layer which comprises the said insulating layer, or its precursor can be obtained by selecting a specific diamine and specific tetracarboxylic dianhydride suitably according to the characteristic, and superposing | polymerizing in a solvent.

As a diamine used for the synthesis | combination of the non-thermoplastic polyimide which forms a non-thermoplastic polyimide layer, o-phenylenediamine, p-phenylenediamine, m-phenylenediamine, 4,4'- diaminophenyl ether, 3, 4'-diaminodiphenylether, 3,3'-diaminodiphenylether, 4,4'-diamino-biphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl, 2, 4,4'- diamino- benzanilide etc. which may have substituents, such as 2'-bis [4- (4-aminophenoxy) phenyl] propane, an alkyl group and an alkoxy group, are illustrated. These may be used alone or in combination of two or more. Moreover, although it can also use together with another diamine, it is preferable that the usage-amount of the said diamine component is 70 mol% or more.

As tetracarboxylic dianhydride used for the synthesis | combination of a non-thermoplastic polyimide, pyromellitic dianhydride, 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride, 2,2', 3,3 '-Biphenyltetracarboxylic acid and the like are exemplified. These may be used alone or in combination of two or more. Moreover, although it is also possible to use together with other tetracarboxylic dianhydride, it is preferable that the usage-amount of the said tetracarboxylic-acid component is 70 mol% or more.

As the non-thermoplastic polyimide forming the non-thermoplastic polyimide layer, a commercially available non-thermoplastic polyimide film or a polyimide solution or a precursor solution thereof may be used. For example, Uffy Kosan Kaibushiki Co., Ltd. of U. pirex (registered trademark) S, SGA, SN, Toray DuPont Kabushi Kaisha, Kapton (registered trademark) H, V, EN, Kanefuchi Kagaku Kogyo Co., Ltd. Apical (R) AH, NPI, the film of HP, etc. or its intermediate are illustrated.

As a diamine used for the synthesis | combination of the thermoplastic polyimide which forms a thermoplastic polyimide layer, 1, 3-bis (4-amino phenoxy) benzene, 4, 4'-bis (3-amino phenoxy) biphenyl, 4, 4'-bis (4-aminophenoxy) biphenyl, 3,3'-diaminobenzophenone, 2,2-bis (4-4-aminophenoxy) phenyl) propane and the like are exemplified. You may use these individually or 2 types or more. Moreover, although it can also use together with other diamine, it is preferable that the usage-amount of the said diamine component is 70 mol% or more.

As tetracarboxylic dianhydride used for the synthesis | combination of a thermoplastic polyimide, a pyromellitic dianhydride, 3,3'4,4'-biphenyl tetracarboxylic dianhydride, 2,2 ', 3,3'- Biphenyl tetracarboxylic acid etc. are illustrated. These may be used alone or in combination of two or more. Moreover, although it is also possible to use together with other tetracarboxylic dianhydride, it is preferable that the usage-amount of the said tetracarboxylic acid is 70 mol% or more.

In the laminate for COF of the present invention, a thermoplastic polyimide or a precursor solution thereof (hereinafter also referred to as varnish) is applied to a metal foil surface, and then a non-thermoplastic polyimide or a precursor solution thereof is applied to the laminate and dried and, if necessary, subjected to heat treatment. It can manufacture by the method of hardening. As a method of applying the varnish, a known method such as a die coater, comma coater, roll coater, gravure coater, curtain coater, spray coater or the like can be adopted. In this case, if necessary, a thermoplastic or non-thermoplastic polyimide or a precursor solution thereof may be applied in multiple layers. When forming a thermoplastic polyimide layer or a non-thermoplastic polyimide layer in multiple layers, they may be same or different. As a method for drying and curing the applied varnish, a normal heat drying furnace can be used. As the drying furnace, air, inert gas (nitrogen, argon) or the like can be used. As temperature of drying and hardening, the temperature range of about 60 to 400 degreeC is used preferably. Hardening is performed until a polyimide precursor turns into a polyimide. Moreover, when copper foil thickness is large, copper foil thickness is made into predetermined thickness by an etching process etc. as needed.

It is preferable to make three or more laminated silver insulation layers which have metal foil on both surfaces, and to make a outermost layer into a thermoplastic polyimide layer, and to heat-bond metal foil to the surface of the thermoplastic polyimide layer of this outermost layer, etc. Do.

In addition, in the laminate for COF of the present invention, a thermoplastic polyimide or a precursor solution thereof is applied to one or both sides of a non-thermoplastic polyimide film, and in the same manner as the above method, a metal foil is formed on the surface of the thermoplastic polyimide layer as a multilayer polyimide layer. It is also possible to manufacture by thermocompression bonding. There is no restriction | limiting in particular about the method of thermocompression bonding, For example, well-known methods, such as a heat press method and a thermal lamination method, can be employ | adopted.

The method of manufacturing the film carrier tape for COF from the laminated board for COF is well-known, These methods can be selected suitably and used. For example, the laminate for COF is cut into a film of a predetermined width, sprockets are provided on both sides of the film, a photosensitive resin layer is formed on the metal foil surface side, and exposed through a mask to obtain a predetermined circuit, followed by etching. The treatment removes either the unexposed portion or the exposed portion. Next, the remaining resin layer is subjected to etching treatment of the exposed metal foil as a resist to form a circuit pattern, and to remove the resist as necessary to form a film carrier tape for COF.

In the electronic device of the present invention, an electronic component is mounted on a wiring board obtained by circuit processing the laminate for COF. And this electronic device can be manufactured as follows. That is, first, a laminated plate having a conductor on one or both sides of the insulating layer is prepared. The insulating layer of the laminate has a multilayer structure composed of two or more polyimide resins, and the glass transition temperature of the insulating layer is 350 ° C or higher and the thermal expansion coefficient of 300 to 350 ° C or lower is 70 ppm / ° C, but the insulating layer is particularly It is preferable to have a thermoplastic polyimide layer on the single side | surface or both surfaces of a thermoplastic polyimide layer, and z value calculated by said formula (1) is 20 or less.

Next, the conductor of the laminate is processed into an arbitrary circuit pattern. The circuit pattern formation of a conductor can apply the method similar to the method of manufacturing the film carrier tape for COF from the said laminated board for COF. In this way, the electronic component is mounted on the circuit processed wiring board. However, the electronic component referred to herein includes bumps for conducting conductive circuit conduction on the wiring board to electronic components such as semiconductor devices represented by IC chips or LSI chips. It is suitable, and mounting is performed at 300 degreeC or more. In the case where the electronic component is a bumped electronic component having a bump, a part of the circuit pattern of the wiring board and the bump of the electronic component are performed. According to the manufacturing method of the electronic device of this invention, since the insulating layer of a laminated body meets specific requirements, even if it mounts at high temperature of 300 degreeC or more, the effect similar to the effect by the COF laminated board of this invention. It is possible to enjoy a good electronic device. Moreover, in the manufacturing method of the electronic device of this invention, since the laminated board to prepare is one of the characteristics, the preferable aspect of a laminated board is suitable also in the manufacturing method of the electronic device of this invention.

1: is sectional drawing for demonstrating the layer structure of the COF laminated board of a single-sided conductor, Comprising: The insulating layer 10 and the conductor 20 are shown. The insulating layer 10 is comprised of three layers, the thermoplastic polyimide layer 11, the non-thermoplastic polyimide layer 12, and the thermoplastic polyimide layer 13, and the thermoplastic polyimide layer 13 is the conductor 10 Is in contact with.

FIG. 2 is a conceptual diagram showing an example of mounting an IC chip on a film carrier tape for COF, wherein a gold-plated bump 2 of the IC chip 1 is formed on the insulating layer 3 of the film carrier tape for COF. The state joined to (4) is shown. At this time, since the thermocompression bonding is carried out at a high temperature of about 350 to 400 ° C., the thickness of the insulating layer 3 of the crimp portion enters T2 from the original thickness T1. It is desired to make this thickness difference T1-T2 as small as possible.

(Example)

Below, an Example demonstrates this invention further in detail.

Abbreviations used in the examples are as follows.

PMDA: pyromellitic anhydride

BPDA: 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride

DAPE: 4,4'-diaminodiphenyl ether

MT: 4,4-diamino-2,2'-dimethylbiphenyl

BAPP: 2,2-bis (4- (4-aminophenoxy) phenyl) propane

BAPB: 4,4'-bis (4-aminophenoxy) biphenyl

TPE: 1,3-bis (4-aminophenoxy) benzene

DMAc: Dimethylacetamide

<Example 1>

425 g of DMAc were dissolved with stirring 28.1 g of MT and 4.3 g of TPE in 1 L of a detachable flask. Next, 25.3 g of PMDA and 8.5 g of BPDA were added little by little to this solution to carry out a polymerization reaction to obtain a high viscosity non-thermoplastic polyimide precursor solution A.

Similarly, 18.0 g of BAPP and 24.3 g of BAPB were dissolved in 425 g of DMAc, and then 24.5 g of PMDA was added to the solution to carry out a polymerization reaction to obtain a high viscosity thermoplastic polyimide precursor solution B.

Next, the polyimide precursor solution B obtained above was imide-converted on the electrolytic copper foil (NA-VLP by Mitsui Kinzoku Co., Ltd.) whose thickness is 18 micrometers and surface roughness Rz of a coating surface is 0.9 micrometer. Barcoat was carried out so that the film thickness after this might become 3 micrometers. Then, it dried for 5 minutes at 130 degreeC. Then, the polyimide precursor solution A was bar-coated so that the film thickness after imide inversion might be set to 33 micrometers, and it dried at 130 degreeC for 5 minutes on the dry polyimide layer. In the same manner, the film was subjected to a bar coat so as to have a thickness of 4 μm after the polyimide precursor solution B was imid-converted on the film, and dried at 130 ° C. for 5 minutes. Next, the dried laminate was put into a vacuum thermostat and heat treated at 200 ° C. for 30 minutes, at 300 ° C. for 30 minutes, at 350 ° C. for 30 minutes, and at 370 ° C. for 10 minutes, so that the polyimide layer had a thickness of 40 μm. A laminated board was obtained.

Here, the thermal expansion coefficient of 300-350 degreeC of the non-thermoplastic polyimide A layer obtained from the polyimide precursor solution A was 30 ppm / degreeC. The thermal expansion coefficient at 300 to 350 ° C of the thermoplastic polyimide B layer obtained from the polyimide precursor solution B was 52 ppm / ° C, the glass transition temperature of the entire polyimide layer was 363 ° C, and the thermal expansion coefficient was 38 ppm / ° C.

The coefficient of thermal expansion was determined from a dimensional change of 300 to 350 ° C. using a thermomechanical analyzer (TMA). The glass transition temperature was measured by dynamic viscoelasticity, and the peak value of the loss modulus was defined as the glass transition temperature.

The wiring pattern of 60 micrometer pitch was formed in the obtained laminated board for COF, and it was set as the COF film carrier tape. In addition, tin plating is performed on the inner lead portion. Thereafter, an IC having gold bumps was mounted on the inner lead portion of the COF film carrier tape, and the underfill was filled and heat cured. Mounting was carried out using a flip chip holder "TFC-2100" manufactured by Shibaura Mechatronics Co., Ltd., with a bonding head tool temperature of 420 ° C, a stage temperature of 100 ° C, and a joining pressure of 20 gf per bump.

Next, it observed under the microscope from the polyimide surface of the COF film carrier tape which mounted IC, and confirmed that there was no deformation | transformation, such as a wave of a polyimide layer, and there was no void in an underfill and a polyimide interface. In addition, the cross section of the COF film carrier tape mounted with IC was observed, and the inner lead wiring penetration amount was measured as T1-T2 = T3 (resin deformation amount due to mounting) shown in FIG. The connection state between and bumps was checked. In this embodiment, T3 was 1.0 占 퐉, and the connection state between the inner lead and the bump was good.

<Example 2>

28.1 g of BAPP and 13.3 g of TPE were dissolved in 1 L of a detachable flask in 425 g of DMAc while stirring. Next, 25.4 g of PMDA was added little by little to this solution, and a polymerization board was carried out to obtain a high viscosity thermoplastic polyimide precursor solution C.

Thereafter, the same operation as in Example 1 was performed using the non-thermoplastic polyimide precursor solution A and the thermoplastic polyimide precursor solution C obtained in Example 1, and the thickness of the polyimide layer was 5 in the order of C / A / C. The laminated board for 40 micrometers of COF of micrometer / 30 micrometers / 5 micrometers was obtained. The thermal expansion coefficient of 300-350 degreeC of the thermoplastic polyimide C layer was 82 ppm / degreeC, and the glass transition temperature of the whole polyimide layer was 367 degreeC, and the thermal expansion coefficient of 300-350 degreeC was 45 ppm / degreeC. As a result of processing with a COF film carrier tape and mounting the IC and filling the underfill, there was no void in the deformation of the polyimide layer and the underfill and polyimide interfaces. Moreover, T3 was 1.5 micrometers, and the adhesive state of an inner lead and the connection state of an inner lead and bump were favorable.

<Example 3>

The non-thermoplastic polyimide precursor solution A obtained in Example 1 was imide-converted on an electrolytic copper foil (NA-VLP manufactured by Mitsui Kinzoku Co., Ltd.) having a thickness of 18 µm and a surface roughness (Rz) of the coated surface of 0.9 µm. Barcoat was carried out so that the thickness of the polyimide layer after the formation would be 35 m. Then, it dried for 5 minutes at 130 degreeC. Then, the thermoplastic polyimide precursor solution C obtained in Example 2 was bar-coated so that the polyimide layer thickness after imide conversion might be set to 5 micrometers, and it dried at 130 degreeC for 5 minutes on the dried polyimide layer. Next, the dried laminate was put into a vacuum thermostat and heat treated at 200 ° C. for 30 minutes, at 300 ° C. for 30 minutes, at 350 ° C. for 30 minutes, and at 370 ° C. for 10 minutes, so that the polyimide layer had a thickness of 40 μm. A laminated board was obtained.

The glass transition temperature of the whole polyimide layer was 366 degreeC and the thermal expansion coefficient of 300-350 degreeC was 45 ppm / degreeC, and it processed similarly to Example 1 with COF film carrier tape, and mounted IC and filled underfill, There was no void in the deformation of the mid layer and the underfill and polyimide interfaces. Moreover, T3 was 0.5 micrometer and the adhesive state of an inner lead and the connection state of an inner lead and bump were favorable.

Comparative Example 1

43.2 g of BAPP was dissolved in 425 g of DMAc while stirring in 1 L of a detachable flask. Subsequently, 19.1 g of PMDA, 4.5 g of BPDA, and 24.5 g of PMDA were added little by little to this solution to carry out a polymerization reaction to obtain a high viscosity thermoplastic polyimide precursor solution D. Thereafter, the same operation as in Example 1 was performed using the non-thermoplastic polyimide precursor solution A and the thermoplastic polyimide precursor solution D obtained in Example 1, and the thickness of the polyimide layer was 3 in the order of D / A / D. The laminated board for COF of 40 micrometers which is micrometer / 33 micrometers / 4 micrometers was obtained. The thermal expansion coefficient of 300-350 degreeC of the thermoplastic polyimide D layer was 800 ppm / degreeC, and the glass transition temperature of the whole polyimide layer was 323 degreeC, and the thermal expansion coefficient of 300-350 degreeC was 352 ppm / degreeC. As a result of processing with a COF film carrier tape and mounting the IC and filling the underfill, the polyimide layer was greatly deformed and voids were generated at the underfill and the polyimide interface. T3 was 4 micrometers, and the contact | adherence state of the inner lead was favorable, but the connection state of the inner lead and bump was bad.

Comparative Example 2

Using the non-thermoplastic polyimide precursor solution A and the thermoplastic polyimide precursor solution C obtained in Example 1, operation similar to Example 1 was performed, and the thickness of a polyimide layer is 10 micrometer / 20 in order of C / A / C. The laminated board for 40 micrometers of COF which is 10 micrometers / 10 micrometers was obtained. The glass transition temperature of the whole polyimide layer was 367 degreeC, and the thermal expansion coefficient of 300-350 degreeC was 80 ppm / degreeC. As a result of processing with a COF film carrier tape and mounting the IC and filling the underfill, the polyimide layer was wave-deformed and voids were generated at the underfill and the polyimide interface. T3 was 2 micrometers, and the contact state of the inner lead was favorable, but the connection state of the inner lead and bump was bad.

Comparative Example 3

Except having changed the thermoplastic polyimide precursor solution C into D, operation similar to Example 3 was performed and the laminated board for COF of 40 micrometers in thickness of a polyimide layer was obtained. The glass transition temperature of the whole polyimide layer was 322 degreeC, and the thermal expansion coefficient of 300-350 degreeC was 250 ppm / degreeC. In the same manner as in Example 1, processing with a COF film carrier tape and mounting the IC and filling the underfill resulted in a large wave deformation of the polyimide layer, and voids were generated at the underfill and the polyimide interface. T3 was 0.5 µm and the adhesion state of the inner lead was good, but the connection state of the inner lead and the bump was poor.

Z and the other results calculated by equation (1) are collectively shown in Table 1 and Table 2. Moreover, Tg of each polyimide layer is polyimide layer A: 371 degreeC, polyimide layer B: 359 degreeC, polyimide layer C: 365 degreeC, and polyimide layer D: 305 degreeC.

According to the present invention, the Au-Au bonding or Au-Sn process in the IC chip mounting process is excellent in dimensional stability, adhesion between the metal wiring and the insulating layer, there is no pinhole, and a high temperature of 300 ° C. or higher is applied for manufacturing COF. In the city, the dimensional change and deformation caused by the heat of the film carrier tape can be suppressed, the bumps of the metal wiring and the IC chip can be prevented, the metal wiring can be prevented from entering the polyimide layer, and the underfill filling can also be performed. The laminated board for COF and COF film carrier tape which improved the electrical connection reliability of a component and a film carrier tape can be provided.

Claims (7)

In a laminate for COF having conductors on one or both sides of the insulating layer, the insulating layer has a multilayer structure made of two or more polyimide resins, and the glass transition temperature of the insulating layer is 350 ° C or higher and 300 to 350 ° C. Laminated sheet for COF, characterized in that the thermal expansion coefficient is 70ppm / ℃ or less. The laminate according to claim 1, wherein the insulating layer has a thermoplastic polyimide layer on one or both sides of the non-thermoplastic polyimide layer, and z calculated by the following formula (1) is 20 or less. z = α × x-β × y (1) (Where α is the thermal expansion coefficient (ppm / ° C.) of 300 to 350 ° C. of the thermoplastic polyimide layer, x is the ratio of the thickness of the thermoplastic polyimide layer to the total thickness of the insulating layer, and β is 300 of the non-thermoplastic polyimide layer. Thermal expansion coefficient (ppm / ° C) of ˜350 ° C., and y is a ratio of the thickness of the non-thermoplastic polyimide layer to the total thickness of the insulating layer.) The laminate sheet for COF according to claim 1 or 2, wherein the surface roughness Rz of the conductor surface directly in contact with the insulating layer is 1.0 µm or less. The laminated sheet for COF according to any one of claims 1 to 3, wherein the insulating layer is obtained by directly applying a precursor solution of polyimide to the conductor and imid-converting it. It is obtained by processing the laminated sheet for COF of any one of Claims 1-4, The film carrier tape for COF characterized by the above-mentioned. An electronic device is mounted on a wiring board obtained by circuit processing a laminate for COF according to claim 4. Conductor is provided on one or both sides of the insulating layer, and the insulating layer has a multilayer structure made of two or more polyimide resins, and the glass transition temperature of the insulating layer is 350 ° C or higher and the thermal expansion coefficient of 300 to 350 ° C is 70 ppm / Preparing a laminate having a temperature lower than or equal to After processing the conductor of the laminated plate in an arbitrary circuit pattern, A method for manufacturing an electronic device mounted with the electronic component, characterized in that the electronic component is mounted on the circuit processed wiring board at 300 ° C or higher.

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