LAMINATE

An object of the invention is to prevent staining of processing equipment by a resin originated from a resin sheet during pressing. The present invention achieves the object by a laminate having a support, a resin sheet that is laminated on a part of the support, and a release sheet that is laminated on the resin sheet, in which a peel force F1 between the support and the resin sheet is larger than a peel force F2 between the resin sheet and the release sheet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present invention is explained by referring to the drawings. However, the present invention is not limited to these examples.FIG. 1Ais a cross-sectional view schematically showing the laminate according to the present embodiment, andFIG. 1Bis a planar drawing of the laminate.

As shown inFIGS. 1A and 1B, a laminate10has a support12, a resin sheet14that is laminated on a part of the support12, and a release sheet16that is laminated on the resin sheet14. The resin sheet14is laminated on a part of the support12so that it does not protrude from the support12in plan view. With this, a part12awhere the resin sheet14is not laminated exists on the support12. Because of that, when the resin sheet14in a state of being laminated on the support12is pressed, the resin spreads on the part12aof the support12where the resin sheet is not laminated. As a result, the protrusion of the resin on the support12can be prevented within the area on the part12a, and the attachment of the resin to processing equipment such as a pressing plate can be prevented. Therefore, staining of the equipment can be suppressed. The staining of the equipment by the resin can be suppressed due to the existence of the support12. Therefore, it is not necessary to provide a protective material or a release film on a top plate of the pressing plate to prevent the attachment of the resin.

As described above, the resin sheet14is laminated on a part of the support12so that it does not protrude from the support12in plan view. The resin sheet14may be laminated on any position of the support12as long as it is laminated so that the part12aexists in a state that it does not protrude from the support12in plan view. However, the resin sheet14is preferably laminated so that the width of the left side12L of the part12afrom the resin sheet14is the same as the width of the right side12R of the part12afrom the resin sheet14in plan view. Likewise, the resin sheet14is preferably laminated so that the width of the upper side12U of the part12afrom the resin sheet14is the same as the width of the lower side12D of the part12afrom the resin sheet14in plan view.

The breadth12W1of the support12should be larger than the breadth14W1of the resin sheet14, preferably 1.2 to 1.5 times, and more preferably 1.2 to 1.3 times the breadth14W1of the resin sheet14. In the same manner, the height12W2of the support12should be larger than the height14W2of the resin sheet14, preferably 1.2 to 1.5 times, and more preferably 1.2 to 1.3 times the height14W2of the resin sheet14. When the breadth12W1of the support12is 1.2 times or more the breadth14W1of the resin sheet14, the protrusion of resin upon pressing can be more effectively suppressed. In the same manner, when the height12W2of the support12is 1.2 times or more the height14W2of the resin sheet14, the protrusion of resin upon pressing can be more effectively suppressed. When the breadth12W1of the support12is 1.5 times or less the breadth14W1of the resin sheet14, the handling at processing such as molding becomes easy, and the handling property can be improved. In the same manner, when the height12W2of the support12is 1.5 times or less the height14W2of the resin sheet14, the handling at processing such as molding becomes easy, and the handling property can be improved. The breadth12W1and the height14W2of the support12can be appropriately set in accordance with the thicknesses of the resin sheet14before and after pressing and the pressure at pressing.

The present embodiment is explained on the assumption that the support12and the resin sheet14are rectangular in plan view. However, in the present invention, the shapes of the support and the resin sheet are not limited to this example. When the support and the resin sheet are not rectangular, the longest distances in the crosswise dimension (diameter in case of a round shape) of the support and the resin sheet are regarded as the breadth. In the same manner, the longest distances in the lengthwise dimension of the support and the resin sheet are regarded as the height.

In the laminate10, the peel force F1between the support12and the resin sheet14is larger than the peel force F2between the resin sheet14and the release sheet16. Because the peel force F1is larger than the peel force F2, the release sheet16can be easily peeled off upon pressing without peeling the resin sheet14from the support12. Examples of the method of making the peel force F1larger than the peel force F2include the selection of materials for the support12and the release sheet16and a surface treatment.

The peel force F1is not especially limited as long as it is larger than the peel force F2. However, it is preferably 0.03 N/10 mm or more and 5 N/10 mm or less, and more preferably 0.05 N/10 mm or more and 3 N/10 mm or less under conditions of a measurement temperature of 23° C., a tensile speed of 0.3 m/min, and a peel angle of 180 degrees. When the peel force F1is 0.03 N/10 mm or more, spontaneous peeling between the resin sheet14and the support12can be prevented. When the peel force F1is 5 N/10 mm or less, the release sheet16can be easily peeled off from the resin sheet before pressing. In addition, deformation of the resin sheet14before curing can be prevented.

The peel force F2is not especially limited as long as it is smaller than the peel force F1. However, it is preferably 0.01 N/10 mm or more and 3 N/10 mm or less, and more preferably 0.03 N/10 mm or more and 2 N/10 mm or less under conditions of a measurement temperature of 23° C., a tensile speed of 0.3 m/min, and a peel angle of 180 degrees. When the peel force F2is 0.01 N/10 mm or more, spontaneous peeling between the resin sheet14and the release sheet16can be prevented. When the peel force F2is 3 N/10 mm or less, only the release sheet16can be peeled off from the support12without peeling the resin sheet14off.

The surface of the support12may be subjected to a conventional surface treatment for the peeling property between the resin sheet14and the support12. Examples of the surface treatment include chemical and physical treatments such as a chromic acid treatment, ozone exposure, flame exposure, high voltage electric shock exposure, and an ionized radiation treatment, and a coating treatment by a primer such as a release-treatment agent. Same type or different types of materials can be appropriately selected and used as the support12, and several types of materials can be blended and used as necessary.

The thickness of the support12is not especially limited, and can be appropriately decided. However, it is preferably 25 to 100 μm, and more preferably 38 to 50 μm. When the thickness of the support12is 25 μm or more, the resin sheet14can be properly supported, and an excellent handing property can be obtained. Meanwhile, when the thickness of the support12is 100 μm or less, the handling property can be improved.

The tensile storage modulus of the support12is preferably 1.5 to 5 GPa, and more preferably 2 to 4.5 GPa at 25° C. When the tensile storage modulus of the support12is 1.5 GPa or more, the handling becomes easy. Meanwhile, when the tensile storage modulus of the support is 5 GPa or less, the peeling of the resin sheet14from the support12can be prevented. Cracking of the resin sheet14can also be prevented.

The coefficient of linear thermal expansion of the support12is preferably 3 to 15 ppm/° C., and more preferably 5 to 10 ppm/° C. in a region (α1region) of equal to or less than the glass transition temperature. The coefficient of linear thermal expansion of the support12is preferably 20 to 60 ppm/° C., and more preferably 25 to 40 ppm/° C. in a region (α2region) of equal to or more than the glass transition temperature. When the coefficient of linear thermal expansion of the support is within the above-described range, the support is considered to have heat resistance (especially, to the heat of about 150° C.). As a result, the support is sufficiently durable against the heat during pressing.

The support12may have a pressure-sensitive adhesive layer. With the pressure-sensitive adhesive layer, the resin sheet14can be securely pasted to the support12. The material of the pressure-sensitive adhesive layer is not especially limited, and conventionally known materials can be adopted. An example is a general pressure-sensitive adhesive such as an acryl-based pressure-sensitive adhesive and a rubber-based pressure-sensitive adhesive. The pressure-sensitive adhesive layer may be formed from a radiation curing-type pressure-sensitive adhesive. As to the radiation curing-type pressure-sensitive adhesive, the degree of crosslinking can be increased by irradiation with radiation such as an ultraviolet ray to easily decrease the adhesive power. Therefore, the resin sheet14can be easily peeled off from the support12by irradiation with radiation after pressing.

The resin sheet14is an object of pressing. The material of the resin sheet14is not especially limited. However, conventionally known thermosetting resins can be mentioned as examples. A thermoplastic resin and various additives may be added as necessary. The use of the resin sheet14is not especially limited, and examples thereof include a resin sheet for sealing electronic parts, an underfill sheet, a film for the backside of a flip-chip semiconductor, and a die bond film. The resin sheet for sealing electronic parts is a sheet that is pasted to the surface of a substrate where electronic parts such as a semiconductor chip are mounted to embed the electronic parts. The underfill sheet is a sheet to seal a space between a circuit surface of a semiconductor chip and an electrode-formed surface of a substrate in a flip-chip semiconductor device. The film for the backside of a slip-chip semiconductor is a film to be formed on the backside (a non-circuit-formed surface) of a semiconductor element that is connected onto an adherend by flip-chip bonding. The die bond film is a film to die bond a semiconductor chip to an adherend.

The thickness of the resin sheet14is not especially limited, and it can be appropriately set in accordance with the use thereof, for example. However, it is generally 100 to 1000 μm, and preferably 200 to 750 μm.

The material of the release sheet16is not especially limited, and the same material as that for the support12can be used.

The surface of the release sheet16may be subjected to a conventional surface treatment for the peeling property from the resin sheet14. The same surface treatment as for the support can be adopted.

The thickness of the release sheet16is not especially limited, and can be appropriately decided. However, it is preferably 38 to 75 μm, and more preferably 38 to 50 μm. When the thickness of the release sheet16is 38 μm or more, a certain level of hardness can be obtained, and the handling property can be improved. Meanwhile, when the thickness of the release sheet16is 75 μm or less, peeling of the resin sheet from the support can be prevented. Cracking of the resin sheet can also be prevented.

In the present embodiment, the shape of the release sheet16is the same as that of the resin sheet14in plan view. However, the shape of the release sheet in the present invention is not limited to this example. However, from the viewpoint of protecting the surface of the resin sheet14before pressing, the release sheet16is preferably formed so that it at least covers the entire resin sheet14.

The area of the support12is larger than that of the release sheet16in plan view. When the area of the support12is larger than that of the release sheet16in plan view, the support12and the release sheet16can be easily distinguished from each other. As a result, the front side can be easily distinguished from the rear side. In the present embodiment, the case is explained in which the area of the support12is larger than that of the release sheet16. However, the present invention is not limited to this example, and the area of the support may be same as that of the release sheet (the support may have the same shape as that of the release sheet) in plan view or it may be larger.

(Method of Manufacturing the Laminate)

A laminate10according to the present embodiment is manufactured as follows, for example. First, a support12and a release sheet16can be formed by a conventionally known film forming method. Examples of the film forming method include a calender film forming method, a casting method in an organic solvent, an inflation extrusion method in a closed system, a T-die extrusion method, a coextrusion method, and a dry laminate method.

When the pressure-sensitive adhesive layer is formed on the support12, a pressure-sensitive adhesive composition solution is applied onto the support12to form a coating film, and the coating film is dried (heated and crosslinked as necessary) under a prescribed condition to form the pressure-sensitive adhesive layer.

Then, a resin composition solution that is a forming material of a resin sheet14is produced. The resin composition solution is applied onto the support12to a prescribed thickness to form a coating film, and the coating film is dried under a prescribed condition to form the resin sheet14. The coating method is not especially limited. However, examples include roll coating, screen coating, and gravure coating. After that, the release sheet16is pasted to the resin sheet14. The resin composition solution may be applied onto the release sheet16to form a coating film, and the coating film may be dried to form the resin sheet14. In this case, the resin sheet14is pasted to the support12together with the release sheet16. As stated above, the laminate10according to the present embodiment can be obtained.

(Method of Processing the Resin Sheet)

The resin sheet14that is provided in the laminate10according to the present embodiment can be processed as follows, for example.

First, the release sheet16is peeled off from the resin sheet14. In the laminate10, the peel force F1between the support12and the resin sheet14is larger than the peel force F2between the resin sheet14and the release sheet16. Therefore, the release sheet16can be easily peeled off from the support12without peeling the resin sheet14off.

Then, the resin sheet14in a state of being laminated on the support12is pressed. The pressing can be performed using a conventionally known pressing apparatus. Because a part12awhere the resin sheet14is not laminated exists on the support12, the resin spreads on the part12aof the support. As a result, the protrusion of the resin on the support12can be prevented, and the attachment of the resin to a pressing plate or the like of a pressing apparatus can be prevented. Therefore, staining of the equipment can be suppressed. In addition, positioning of the resin sheet upon pressing can be performed using the part12aof the support12where the resin sheet14is not laminated. An example of the pressing method is a method of heating the pressing plate (preferably to 60 to 110° C. and more preferably to 60 to 90° C.) to soften the resin sheet14and pressing the resin sheet14(preferably at 0.5 to 15 kg/cm2and more preferably at 2 to 5 kg/cm2). The amount of pressing is preferably 10 to 500 μm, and more preferably 30 to 300 μm as an amount of pushing from the contact of the pressing plate to the top surface of the resin sheet14. In the pressing, both top and bottom pressing plates may be heated or only one of them may be heated.

Then, processes are performed such as a punching process by a Thomson blade or the like and a slitting process by a slitter or the like. After that, the resin sheet14is peeled off from the support12to obtain the resin sheet14is formed into a desired shape.

EXAMPLES

Preferred examples of the invention are explained in detail below. However, the materials, the compounding amount, and the like described in these examples are not to limit the features of the invention as long as there is no special description of limitation.

<Preparation of the Support>

A support A made of PET (polyethylene terephthalate) having a size of 60 mm long×15 mm wide×38 μm thick was prepared.

A support B made of PET (polyethylene terephthalate) having a size of 55 mm long×15 mm wide×50 μm thick was prepared.

<Preparation of the Resin Sheet>

The following ingredients were kneaded by a biaxial double kneading machine to prepare a kneaded material.

Then, extrusion molding was performed on the kneaded material to obtain a resin sheet A of 50 mm long×10 mm wide×300 μm thick.

The following ingredients were kneaded by a biaxial double kneading machine to prepare a kneaded material.

Then, extrusion molding was performed on the kneaded material to obtain a resin sheet B of 50 mm long×10 mm wide×300 μm thick.

<Preparation of the Release Sheet>

A release sheet A made of PET (polyethylene terephthalate) having a size of 50 mm long×10 mm wide×300 μm thick was prepared.

<Preparation of the Laminate>

The resin sheet A was laminated on the support A, and the release sheet A was laminated thereon to form a laminate A.

The resin sheet B was laminated on the support B, and the release sheet A was laminated thereon to form a laminate B.

<Measurement of the Peel Force>

The peel force F1between the support A and the resin sheet A was measured to be 0.3 N/10 mm.

The peel force F1between the support B and the resin sheet B was measured to be 1.8 N/10 mm.

The peel force F2between the resin sheet A and the release sheet A was measured to be 0.05 N/10 mm.

The peel force F2between the resin sheet B and the release sheet A was measured to be 0.3 N/10 mm.

The peel force F1and the peel force F2are measured by AUTOGRAPH AGS-J (trade name) manufactured by Shimadzu Corporation under conditions of a measurement temperature of 23° C., a tensile speed of 0.3 m/min, and a peel angle of 180 degrees.

<Measurement of the Tensile Storage Modulus of the Support>

The tensile storage modulus of the support A at 25° C. was measured to be 1.6 GPa.

The tensile storage modulus of the support B at 25° C. was measured to be 3.15 GPa.

The tensile storage modulus was measured by RSA-2 (trade name) manufactured by TA Instruments under the condition of a frequency of 1 Hz.

<Measurement of the Coefficient of Linear Thermal Expansion of the Support>

The coefficient of linear thermal expansion of the support A was 5 ppm/° C. in a region (α1region) of equal to or less than the glass transition temperature, and 31 ppm/° C. in a region (α2region) of equal to or more than the glass transition temperature.

The coefficient of linear thermal expansion of the support B was 7 ppm/° C. in a region (α1region) of equal to or less than the glass transition temperature, and 38 ppm/° C. in a region (α2region) of equal to or more than the glass transition temperature.

The coefficient of linear thermal expansion was measured by TMA8310 manufactured by Rigaku Corporation under conditions of a temperature rise rate of 10° C./min, a measurement temperature region of 50 to 200° C., and a load of 24.5 mN.

Evaluation of the Pressing

The laminate A was pressed using an instant vacuum laminating apparatus VS008-1515 manufactured by Mikado Technos Co., Ltd. The conditions of pressing were a pressing amount (a pushing distance) of 100 μm, a temperature of the pressing plate of 90° C., and an applied pressure of 5 kg/cm2.

The laminate B was pressed using an instant vacuum laminating apparatus VS008-1515 manufactured by Mikado Technos Co., Ltd. The conditions of pressing were a pressing amount (a pushing distance) of 100 μm, a temperature of the pressing plate of 90° C., and an applied pressure of 5 kg/cm2.

The laminate B was pressed using an instant vacuum laminating apparatus VS008-1515 manufactured by Mikado Technos Co., Ltd. The conditions of pressing were a pressing amount (a pushing distance) of 150 μm, a temperature of the pressing plate of 90° C., and an applied pressure of 5 kg/cm2.

The laminate B was pressed using an instant vacuum laminating apparatus VS008-1515 manufactured by Mikado Technos Co., Ltd. The conditions of pressing were a pressing amount (a pushing distance) of 200 μm, a temperature of the pressing plate of 90° C., and an applied pressure of 5 kg/cm2.

The results of pressing were evaluated as follows. That is, the case where there was no protrusion of the resin sheet from the support was evaluated as ◯, and the case where there was protrusion of the resin sheet from the support was evaluated as x. The results are shown in Table 1.