TWI783021B - Heat peeling method for processing inspection objects - Google Patents

Abstract

A heat-peeling method for processing an object to be inspected, characterized by having the following steps (I) and (II), Step (I): an adhesive sheet on a non-adhesive heat-expandable substrate and an adhesive layer (X1) The step of attaching a plurality of objects to be processed and inspected on the adhesive surface of the adhesive layer (X1), the non-adhesive heat-expandable base material containing resin and heat-expandable particles, step (II): a part of the aforementioned heat-expandable base material A step of selectively peeling off a part of the plurality of processed inspection objects by heating to a temperature above which the thermally expandable particles expand.

Description

Heat peeling method for processing inspection objects

The present invention relates to a heat peeling method for processing inspection objects. More specifically, the present invention relates to a method of selectively heating and peeling off a part of a processed inspection object temporarily fixed to an adhesive sheet.

Adhesive sheets are used not only for semi-permanently fixing components, but also for temporarily fixing building materials, interior decoration materials, and electronic parts when processing them. In such an adhesive sheet for temporary fixation, both the adhesiveness to the adherend during use (temporary fixation) and the peelability of the adherend after use are required.

For example, Patent Document 1 discloses an adhesive sheet used for cutting electronic parts. The adhesive sheet is provided with a heat-expandable adhesive layer containing heat-expandable particles on at least one side of the substrate. Also, in this adhesive sheet, the maximum particle size of the thermally expandable particles is adjusted relative to the thickness of the thermally expandable adhesive layer, and the centerline average roughness of the surface of the thermally expandable adhesive layer before heating is adjusted to be 0.4 μm or less. Patent Document 1 describes that the adhesive sheet can ensure the contact area with the adherend when the electronic component is cut (temporarily fixed), and can exhibit the purpose of adhesiveness that can prevent bonding failures such as chip scattering. In addition, it is described that after use (after electronic parts are cut), the heat-expandable particles are expanded by heating to reduce the contact area with the adherend, so that the object can be easily peeled off. Prior Art Documents Patent Documents

Patent Document 1: Japanese Invention Patent No. 3594853

The problem to be solved by the invention

However, in the heat-peelable adhesive sheet disclosed in Patent Document 1, generally speaking, when the adherend is peeled off from the adhesive sheet, heat treatment is applied to the entire surface of the adherend so that the entire adherend is peeled off at once. The state of use. However, in recent years, when heat peeling is performed, among the plurality of adherends attached to the adhesive sheet, there is an increasing demand for only a part of the adherend to be peeled off and the rest to be kept attached to the adhesive sheet. Specifically, for example, the processing steps of FPC (Flexible Printed Circuit, Flexible Printed Circuit) parts laminated with thin layers of copper foil and polyimide film include attaching parts to heat-peelable adhesive sheets, After fixation and cutting processing, the whole surface of the adhesive sheet is heat-treated, and the entire part is peeled off, and a part of the cut piece of the part is moved and separated. In this step, the vibration generated when some of the cut pieces are moved and separated may cause deformation or drop-off of other cut pieces. In addition, in the dicing step of semiconductor wafers or multilayer capacitors, after the dicing process, when the heat-peelable adhesive sheet holding the adherend is heated to peel the adherend, the adherend that is to be kept must be maintained. The whole adherend of the object is separated from the adhesive sheet. In addition, there is a problem that the position of the adherend remaining on the adhesive sheet is shifted or dropped due to the vibration generated when the adherend after processing is moved or separated. Furthermore, according to the inspection results of multiple adherends, there is also a requirement that only a part of the adherends be peeled off, and the rest remain attached to the adhesive sheet. Therefore, for an adherend that requires at least one of processing and inspection (hereinafter also referred to as "processing inspection object"), it is considered to use the heat-peelable adhesive sheet disclosed in Patent Document 1 for temporary fixation. After at least one of processing and inspection, by partially heating the adhesive sheet, a part of the plurality of processing inspection objects attached to the adhesive sheet is selectively peeled off, and the remaining processing inspection objects are Maintain the state attached to the adhesive sheet. By this, it is considered that the deformation, positional deviation and In addition, it is considered that it is also possible to respond to the request that only a part of the processed inspection object should be peeled off according to the inspection results, and the remaining processed inspection object should be kept attached to the adhesive sheet.

However, in the adhesive sheet disclosed in Patent Document 1, when heat-expandable particles are included in the adhesive layer, residues from the heat-expandable particles adhere to the surface of the object to be inspected during processing, or due to expansion of the heat-expandable particles. Due to the deformation of the adhesive layer, a part of the adhesive layer adheres (so-called "residual adhesive") to the surface of the processed inspection object, which may contaminate the surface of the processed inspection object after heat peeling.

The object of the present invention is to provide a method of heat-peeling a processed inspection object using an adhesive sheet, in which residues from thermally expandable particles are prevented from adhering to the surface of the processed inspection object or caused by residual glue on the surface of the processed inspection object. Contamination of the surface of the processed inspection object after thermal peeling is caused, and at the same time, a desired part can be selectively heated and peeled among the plurality of processed inspection objects attached to the adhesive sheet. means of solving problems

The inventors of the present invention found that the above-mentioned problems can be solved by using an adhesive sheet having a non-adhesive heat-expandable base material containing a resin and heat-expandable particles and an adhesive layer.

That is, the present invention relates to the following [1] to [14]. [1] A heat-peeling method for processing an object to be inspected, characterized in that it has the following steps (I) and (II). The step of attaching a plurality of objects to be processed and inspected on the adhesive surface of the adhesive layer (X1) of the adhesive sheet, the non-adhesive heat-expandable substrate contains resin and heat-expandable particles, step (II): the aforementioned heat-expandable base A step of heating a part of the material to a temperature above which the thermally expandable particles expand, and selectively peeling off a part of the plurality of processed inspection objects. [2] The method as described in [1], wherein the aforementioned step (I) has the following steps (I-1) to (I-2), step (I-1): on the adhesive layer of the aforementioned adhesive sheet (X1 ), step (I-2): attaching the previously processed and inspected object pasted on the aforementioned adhesive surface to individual pieces step. [3] The method according to [1] or [2], wherein the adhesive sheet has an adhesive layer (X2) on the opposite side of the heat-expandable substrate to which the adhesive layer (X1) is laminated. The double-sided adhesive sheet is used by sticking a hard support on the adhesive surface of the adhesive layer (X2) of the double-sided adhesive sheet. [4] The method as described in [3], wherein step (I) has the following steps (I-A1) to (I-A3), step (I-A1): placing a plurality of semiconductor wafers on the adjacent semiconductor wafers The step of providing a gap between the chips and placing them on the adhesive surface of the adhesive layer (X1), the step (I-A2): covering the plurality of semiconductor chips and the peripheral parts of the plurality of semiconductor chips with a packaging material The step of adhering the surface and hardening the packaging material to obtain a package in which the plurality of semiconductor chips are packaged in the hardening packaging material, step (I-A3): the step of dividing the package into pieces in units of the semiconductor wafer . [5] The method according to [1] or [2], wherein the adhesive sheet is used by attaching a frame member formed with an opening to the adhesive surface of the adhesive layer (X1). [6] The method as described in [5], wherein step (I) has the following steps (I-B1) to (I-B3), step (I-B1): placing a plurality of semiconductor wafers on the adjacent semiconductor wafers The step of providing a gap between the chips while placing them on the adhesive surface of the adhesive layer (X1) exposed in the aforementioned opening of the aforementioned frame member, step (I-B2): covering the aforementioned plurality of semiconductor chips and The step of hardening the packaging material on the adhesive surface of the peripheral portion of the plurality of semiconductor chips to obtain a package in which the plurality of semiconductor chips are packaged in the hardened packaging material, step (I-B3): using the semiconductor chip unit A step of individualizing the aforementioned packages. [7] The method according to any one of [1] to [6], wherein the heating in the step (II) is performed on the opposite side of the heat-expandable substrate to which the adhesive layer (X1) is laminated . [8] The method according to any one of [1] to [7], wherein the thermally expandable base material satisfies the following requirement (1): Requirement (1): storage modulus E' at 23°C (23 ) is 1.0×10 ⁶ Pa or more. [9] The method according to any one of [1] to [8], wherein the thermally expandable base material satisfies the following requirement (2): Requirement (2): storage modulus E' at 100°C (100 ) is 2.0×10 ⁵ Pa or more. [10] The method according to any one of [1] to [9], wherein the thermally expandable particles have an expansion start temperature (t) of 120 to 250°C, and the thermally expandable substrate satisfies the following requirement (3) , ・Requirement (3): The storage modulus E'(t) at the expansion start temperature (t) is 1.0×10 ⁷ Pa or less. [11] The method according to any one of [1] to [10], wherein the storage shear modulus G'(23) of the adhesive layer (X1) at 23°C is 1.0×10 ⁴ to 1.0×10 ^8Pa . [12] The method according to any one of [1] to [11], wherein the ratio of the thickness of the thermally expandable substrate to the thickness of the adhesive layer (X1) at 23°C (thermally expandable substrate/adhesive Agent layer (X1)) is 0.2 or more. [13] The method according to any one of [1] to [12], wherein the thermally expandable substrate has a thickness of 10 to 1000 μm at 23°C, and the adhesive layer (X1) has a thickness of 1 to 60 μm. [14] The method according to any one of [1] to [13], wherein the probe viscosity value of the surface of the thermally expandable base material is less than 50 mN/5 mmφ. [15] The method according to any one of the above [1] to [14], wherein the thermally expandable particles have an average particle diameter before expansion at 23° C. of 3 to 100 μm. The effect of the invention

According to the present invention, the residue from thermally expandable particles can be suppressed from adhering to the surface of the processing inspection object or contamination of the surface of the processing inspection object after heating and peeling caused by the residual glue on the surface of the processing inspection object, and at the same time, it can be attached to the adhesive Among the plurality of processed inspection objects of the sheet, a desired part is selectively heated and peeled off.

Form of implementing the invention

In the present invention, the term "active ingredient" refers to a component that excludes a diluting solvent among the components contained in the target composition. In addition, the mass average molecular weight (Mw) is a value in terms of standard polystyrene measured by gel permeation chromatography (GPC), and specifically, it is a value measured by the method described in Examples.

In the present invention, for example, "(meth)acrylic acid" means both "acrylic acid" and "methacrylic acid", and the same applies to other similar terms. In addition, regarding preferable numerical ranges (for example, ranges of content, etc.), the lower limit value and upper limit value described hierarchically can be combined independently. For example, according to the description of "preferably 10-90, more preferably 30-60", it is also possible to combine "preferably lower limit (10)" and "better upper limit (60)" to become " 10~60".

<Heat peeling method for processing inspection object> The heat peeling method for processing inspection object of this embodiment has the following steps (I) and (II). The step of attaching a plurality of objects to be processed and inspected on the adhesive surface of the adhesive layer (X1) of the adhesive sheet of the adhesive layer (X1), the non-adhesive heat-expandable base material containing resin and heat-expandable particles, step (II) : A step of heating a part of the heat-expandable substrate to a temperature above which the heat-expandable particles expand, and selectively peeling off a part of the plurality of processed inspection objects. In the following, firstly, the outline of the structure of the adhesive sheet used in the heat-peeling method of processing the inspection object according to this embodiment will be described, and then each step including steps (I) and (II) will be described. In addition, the detail of the constituent material of an adhesive sheet etc. is mentioned later.

[Configuration of Adhesive Sheet] The adhesive sheet of this embodiment is not particularly limited as long as it has a non-adhesive thermally expandable base material containing resin and thermally expandable particles and an adhesive layer. Figures 1 and 2 show the composition of the adhesive sheet of this embodiment, which are cross-sectional model views of the adhesive sheet.

As the adhesive sheet of this embodiment, the adhesive sheet (one-sided adhesive sheet) 1a which has an adhesive layer (X1) 121 on the thermally expandable base material 11 as shown in FIG.1(a) is mentioned. Furthermore, the adhesive sheet of this embodiment can also be an adhesive sheet 1b as shown in FIG. 1(b), which further has a release material 131 on the adhesive surface of the adhesive layer (X1) 121.

The adhesive sheet of this embodiment can be a double-sided adhesive sheet 2a as shown in Figure 2(a), which has a thermally expandable substrate 11 sandwiched by an adhesive layer (X1) 121 and an adhesive layer (X2) 122. Hold the composition. Also, the double-sided adhesive sheet 2b as shown in FIG. 2(b) may further have a release material 131 on the adhesive surface of the adhesive layer (X1) 121, and a release material 131 on the adhesive surface of the adhesive layer (X2) 122. It further has a structure of peeling material 132 .

Moreover, in the double-sided adhesive sheet 2b shown in FIG. When the peeling force is the same level, if the two release materials are pulled to the outside to peel off, the adhesive layer will be split and torn apart along with the two release materials. From the viewpoint of suppressing such a phenomenon, it is preferable to use two types of release materials designed so that the release forces of the two release materials 131 and 132 from the adhesive layers adhered to each other are different.

As another adhesive sheet, in the double-sided adhesive sheet 2a shown in FIG. A release material with release treatment on both sides is a double-sided adhesive sheet that is wound into a roll.

Moreover, in the adhesive sheet of this embodiment, the adhesive sheets 1a and 1b shown in FIG. 1, and the double-sided adhesive sheets 2a and 2b shown in FIG. The composition of the adhesive layer may have another layer between the heat-expandable base material and the adhesive layer.

[Step (I)] In step (I), a plurality of processing checks are attached on the adhesive surface of the adhesive layer (X1) of the adhesive sheet of the non-adhesive heat-expandable base material and the adhesive layer (X1). In the step of the object, the non-adhesive heat-expandable substrate contains resin and heat-expandable particles. The adhesive sheet is the above-mentioned adhesive sheet. For example, the single-sided adhesive sheet 1a shown in FIG. 1 and the double-sided adhesive sheet 2a shown in FIG. 2 can be used. Fig. 3(a) is a schematic cross-sectional view illustrating step (I) of the heat-peeling method for processing and inspecting objects of this embodiment using the single-sided adhesive sheet 1a, and Fig. 3(b) is a schematic plan view. Also, Fig. 4(a) is a schematic cross-sectional view illustrating step (I) of the heat-peeling method for processing and inspecting an object of this embodiment using the double-sided adhesive sheet 2a, and Fig. 4(b) is a schematic plan view.

As shown in FIG. 3( a ) and FIG. 3( b ) and FIG. 4( a ) and FIG. 4( b ), the adhesive sheets 1 a and 2 a are preferably used for being fixed by a fixing means 60 . Thereby, when the processing inspection object is processed or peeled off, it is possible to suppress processing failure or positional displacement of the processing inspection object due to movement of the adhesive sheet. As the fixing means 60 , for example, fixing of a ring frame, fixing of a base, fixing by vacuum suction, etc. are mentioned.

Here, in the heat-peeling method of processing the inspection object of this embodiment, for example, when using the single-sided adhesive sheet 1a as shown in FIG. 1, as shown in FIG. X1) The frame member 20 is attached to the adhesive surface 121a of 121 and used. Thereby, the one-sided adhesive sheet 1a is supported by the frame member 20, and the one-sided adhesive sheet 1a is maintained in a flat state. Therefore, the handleability of the single-sided adhesive sheet 1a in the step (I) and the step (II) is improved. In addition, the workability at the time of placing and affixing the object to be inspected by additional processing on the single-sided adhesive sheet 1a is also improved. Furthermore, when the single-sided adhesive sheet 1a has the release material 131, the release material 131 is peeled off in advance. The frame member 20 is provided with one or more openings 21 penetrating through the front and back of the frame member 20. The shape of the opening 21 is not particularly limited as long as it can house the processed inspection object 7, 7a in the frame. Moreover, the depth of the hole of the opening part 21 is not specifically limited as long as it can accommodate the processed inspection object 7, 7a in a frame. Furthermore, from the viewpoint of further improving the support function of the frame member 20 for the single-sided adhesive sheet 1a, the frame member 20 preferably has a plurality of openings 21 . In addition, when the frame member 20 has a plurality of openings 21, the shape of the openings 21 is preferably formed in a lattice shape, for example. Furthermore, in this embodiment, the so-called "attaching a plurality of processing and inspection objects" means that when the frame member 20 has a plurality of openings 21, it means that the sticking surface exposed from the plurality of openings 21 For each, one or more processed inspection objects are attached. Alternatively, when the frame member 20 has one opening 21 , it means that a plurality of processing and inspection objects are attached to the adhesive surface exposed from the one opening 21 . Furthermore, when the frame member 20 has a plurality of openings 21, the position of the object to be processed and inspected attached to the adhesive sheet can be grasped by the addresses of the plurality of openings 21. The advantage of being easy to control the heating means or pick-up means which will be described later. The frame member 20 is preferably formed of a heat-resistant material. As the material of the frame member 20, metals such as copper, stainless steel, and 42 alloy; polyimide resin, polyacetal resin, polyamide resin, polycarbonate resin, modified polyphenylene ether resin, and Resins called engineering plastics such as polybutylene terephthalate resins; composite materials such as glass epoxy resins, etc. The thickness of the frame member 20 (thickness in the vertical direction with respect to the adhesive surface of the adhesive layer (X1)) may be appropriately determined in consideration of mechanical strength and operability, and is, for example, 100 μm to 3 mm.

Also, in the heat-peeling method of processing the inspection object in this embodiment, for example, when using a double-sided adhesive sheet 2a as shown in FIG. 2, it is preferable that, as shown in FIG. The hard support 14 is attached to the adhesive surface 122a and used. Thereby, the double-sided adhesive sheet 2a is supported by the rigid support 14, and the double-sided adhesive sheet 2a is maintained in a flat state. Therefore, the handleability of the double-sided adhesive sheet 2a in the step (I) and the step (II) is improved. In addition, the workability at the time of mounting and sticking the adherend on the double-sided adhesive sheet 2a is also improved. Furthermore, when the double-sided adhesive sheet 2a has the release material 132, the release material 132 is peeled off in advance. From the viewpoint of achieving the above purpose, the hard support 14 is preferably attached to the entire surface of the adhesive surface 122a of the adhesive layer (X2) 122. Therefore, the hard support 14 is preferably plate-shaped. In addition, the area of the hard support 14 attached to the adhesive surface 122a of the adhesive layer (X2) 122 is preferably larger than the area of the adhesive surface 122a of the adhesive layer (X2) 122 . The material of the hard support 14 may be appropriately determined in consideration of mechanical strength, heat resistance, etc., for example, metal materials such as SUS; non-metallic inorganic materials such as glass and silicon wafers; polyimide and polyamide Resin materials such as imide, composite materials such as glass epoxy resin, etc. Among them, SUS, glass, silicon wafer, etc. are preferable. The thickness of the rigid support 14 may be appropriately determined in consideration of mechanical strength, handleability, etc., and is, for example, 100 μm to 50 mm.

The plurality of processing inspection objects 7, 7a are not particularly limited as long as they are attached to the adhesive sheets 1a, 2a and temporarily fixed, and are necessary for at least one of processing and inspection. The processed inspection object is, for example, a substrate such as a silicon wafer that has been separated into pieces (single pieces). In addition, the processing inspection target object may be a laminate in which two or more members are laminated. In addition, the two or more member systems may be of the same type or of different types. Also, there is no particular limitation on the type of processing performed on the object to be inspected, and examples include wiring formation and resin encapsulation to be described later. There are no particular limitations on the inspection of processed inspection objects, and examples include defect inspections using optical microscopes or lasers (such as dust inspections, surface flaw inspections, wiring pattern inspections, etc.), visual surface inspections, and the like.

[Step (II)] In step (II), a part of the thermally expandable substrate is heated to a temperature above which the thermally expandable particles expand, and a part of the plurality of processing inspection objects is selectively peeled off. The aforementioned plurality of processing inspection objects are selectively peeled off after performing at least one of the above-mentioned processing and inspection, for example. Fig. 5 is a schematic cross-sectional view illustrating the step (II) of the heat-peeling method of the object to be processed and inspected using the single-sided adhesive sheet 1a in this embodiment. Fig. 5(a) shows that the object to be inspected and processed to be peeled off 7a In the previous state, Fig. 5(b) shows a state in which the processed inspection object 7a to be peeled off is peeled off and recovered. Also, Fig. 6 is a schematic cross-sectional view illustrating the step (II) of the heat-peeling method of the processed inspection object using the double-sided adhesive sheet 2a in this embodiment, and Fig. 6 (a) shows the processed inspection object to be peeled off. The state before 7a is peeled off, Fig. 6(b) shows the state of peeling off and recovering the processed inspection object 7a to be peeled off.

Here, in the heat-peeling method of processing an inspection object according to this embodiment, a single-sided adhesive sheet 1a is used, and the frame member 20 is attached to the adhesive surface 121a of the adhesive layer (X1) 121 of the single-sided adhesive sheet 1a. When in use, it is also possible to use a fixing jig or the like to make the entire surface of the heat-expandable base material 11 opposite to the side to which the adhesive layer (X1) 121 is laminated (hereinafter also referred to simply as the “back surface”) become In a fixed state, implement step (II). By fixing the back surface with a fixing jig or the like, formation of unevenness on the back side due to expansion of the heat-expandable particles can be suppressed. Accordingly, unevenness can be efficiently formed on the adhesive surface 121 a side of the adhesive layer ( X1 ) 121 . Therefore, a desired object to be processed and inspected can be easily peeled off from the single-sided adhesive sheet 1a. For example, as a fixing jig, a suction table having a plurality of suction holes and a decompression mechanism such as a vacuum pump can be used. The decompression mechanism sucks the adhesive sheet from the plurality of suction holes and fixes the adhesive sheet to the suction surface.

Furthermore, in the heat-peeling method of processing the inspection object according to the present embodiment, as shown in FIG. When the hard support 14 is attached to the adhesive surface 122a and used, when the thermally expandable particles are expanded, the formation of irregularities on the adhesive surface 122a of the adhesive layer (X2) 122 can be suppressed. Accordingly, unevenness can be efficiently formed on the adhesive surface 121 a side of the adhesive layer ( X1 ) 121 . Therefore, a desired object to be processed and inspected can be easily peeled off from the double-sided adhesive sheet 2a. Furthermore, such an effect can also be achieved when a hard support is adhered to the back side of the single-sided adhesive sheet 1a and used.

As the way of heating in the step (II), as long as it can be heated to more than the temperature at which the thermally expandable particles in the thermally expandable substrate 11 expand, then there is no particular limitation. For example, electric heaters, dielectric heating, and magnetic heating can be suitably used. ; Heating of electromagnetic waves such as near-infrared, mid-infrared, and far-infrared. Furthermore, the heating method can be any heating method of direct heating method and indirect heating method.

In step (II), the heating means 80 for heating the heat-expandable base material 11 of the adhesive sheet has a heating part 81 . The material of the heating portion 81 is appropriately selected according to the heating method. For example, when an electric heater is used as the heating method, the heating unit 81 is composed of a material with high thermal conductivity such as a metal material and a heat insulating material such as artificial mineral fiber. Also, from the viewpoint of more selectively and efficiently heating the area to be heated, an elastic body such as rubber (thermally conductive elastic body) may be provided at the front end of the heating part, and the elastic body may be pressed to the area to be heated. while heating.

The shape or size of the heating portion 81 in the heating means 80 can be appropriately designed according to the shape of the processed inspection object 7a to be peeled off. If the heating part 81 having a shape matching the processed inspection object 7a to be peeled off is used If the heating means 80 heats the sticking part, then in the heat-expandable substrate 11, in the region corresponding to the sticking part, the heat-expandable particle system expands. Thereby, in the adhesive surface 121a of the adhesive layer (X1) 121, in the region corresponding to the sticking part, the contact area with the processing inspection object 7a to be peeled off is reduced and the adhesive force is lost. Therefore, the processed inspection object 7a to be peeled off can be selectively peeled off, and can be easily recovered by, for example, a pickup means such as the suction nozzle 15 .

Furthermore, from the viewpoint of selectively peeling off the processed inspection object attached to a desired position on the adhesive sheet, the heating means 80 is preferably in the X-axis direction and the Y-axis direction of the XY plane of the adhesive sheet. Those who can move. Also, it is preferable that the pick-up means such as the suction nozzle 15 is movable in the X-axis direction and the Y-axis direction of the XY plane of the adhesive sheet. In addition, pick-up means such as the heating means 80 and the adsorption nozzle 15 may be movable in the Z-axis direction.

The "XY plane" in this specification means a plane perpendicular to the lamination direction (thickness direction) of the adhesive sheet. The X-axis and the Y-axis are orthogonal to each other, and become axes in the XY plane. The Z axis is in a relationship orthogonal to the X axis and the Y axis, and is an axis parallel to the lamination direction (thickness direction) of the adhesive sheet. In addition, plural heating means and pick-up means may be provided. At this time, for example, m (m is an integer satisfying 1<m<n) processed inspection objects among n (n is an integer of 3 or more) processed inspection objects can be simultaneously heated and peeled for recovery.

In addition, the heating means and the pick-up means may have a size capable of simultaneously heating and peeling two or more adjacent processed inspection objects. At this time, a plurality of processed inspection objects may be heated and peeled off at the same time, and recovered. In addition, a plurality of heating means and pick-up means capable of simultaneously heating and peeling off the size of two or more adjacent processed inspection objects may be provided.

The heating temperature of the heating means 80 is "a temperature above the temperature at which the thermally expandable particles expand". The temperature "above the temperature at which heat-expandable particles expand" is "a temperature above the expansion start temperature (t) of heat-expandable particles", preferably "expansion start temperature (t) + 10°C" or "expansion start temperature (t) + 60°C" or lower, more preferably "expansion start temperature (t)+15°C" or higher and "expansion start temperature (t)+40°C" or lower. Specifically, depending on the type of the heat-expandable particle, it can be heated to a range of, for example, 120 to 250° C. to expand it.

The heating time of the heating means 80 is set so that only the processed inspection object 7a that should be peeled off can be peeled off, and the attached area of the other processed inspection objects 7 is not heated to a temperature "above the temperature at which the thermally expandable particles expand" .

Here, the heating means 80 may be installed on the processing inspection object side, or may be installed on the opposite side to the processing inspection object side. In other words, the heating means 80 can be arranged on the side of the thermally expandable substrate 11 where the adhesive layer (X1) 121 is laminated, or on the side of the thermally expandable substrate 11 where the adhesive layer (X1) 121 is laminated. opposite side. Alternatively, it can also be arranged on both sides to shorten the heating time. Here, in one aspect of the present invention, it is preferable to install the heating means 80 on the side opposite to the side where the object to be inspected is processed. In the adhesive sheet used in the present invention, when thermally expandable particles are contained in the base material, compared with the case where thermally expandable particles are contained in the adhesive layer (adhesive layer for attaching the object to be inspected during processing), the thermally expandable particle system It exists at a closer distance from the heating means 80 . Therefore, the thermally expandable particles can be easily heated, and the heating time can be shortened. Also, the farther the distance between the heat system from the heating means 80 and the heating means 80 is, the easier it is to diffuse in a direction horizontal to the direction in which the heat advances. Therefore, when the heating means 80 is installed on the side opposite to the processed inspection object side, if thermally expandable particles are contained in the adhesive layer (adhesive layer for attaching the processed inspection object), the adhesive layer will be heated. The heat-expandable particles expand over a wider area than the desired area, and there is a possibility that the object to be processed and inspected attached to the area where peeling is not desired may be peeled off. On the other hand, with the adhesive sheet used in the present invention, since the thermally expandable particles in the thermally expandable substrate at a distance closer to the heating means 80 than the adhesive layer are expanded, the object to be processed and inspected is peeled off. The heat is irradiated in a state in which diffusion is suppressed in the adhesive layer (X1) than in the thermally expandable substrate. Therefore, only the desired area can be selectively heated, and only the desired processed inspection object can be easily and selectively peeled off.

Furthermore, when the heating means 80 is arranged on the processing inspection object side, if the processing inspection object is a material with low thermal conductivity, the heat will not spread to the lower layer of the processing inspection object, and the thermally expandable particles will not be expanded, and the processing inspection object will be processed. Detachment becomes difficult. As mentioned above, when the heating means 80 is provided on the opposite side to the processed inspection object, it is possible to easily peel off all processed inspection objects regardless of the type of processed inspection object. Therefore, by providing the heating means 80 on the processing inspection object side, there is an advantage that only the desired processing inspection object can be selectively peeled off regardless of the type of the processing inspection object.

In addition, when using a fixed jig to fix the back of the single-sided adhesive sheet, or when using a hard support on the adhesive layer (X2) of the double-sided adhesive sheet, it is preferable to process the inspection object oppositely. The heating means 80 is provided on the side, and at the same time, among the fixing jig and the hard support, a material with high thermal conductivity such as a metal material is used to form an area corresponding to the attachment area of the processing inspection object, and a material with low thermal conductivity such as a heat insulating material is used. constitute other regions. Thereby, a desired region can be selectively heated by the heating means 80, and only the desired processed inspection object can be easily and selectively peeled off.

In addition, from the viewpoint of peeling off the object to be processed and inspected more quickly, step (II) may be carried out after preheating the entire adhesive sheet to a temperature at which the heat-expandable particles do not expand. In this way, since the entire adhesive sheet is first heated to a temperature at which the thermally expandable particles do not expand, when the object to be processed and inspected is selectively peeled off, the desired region can quickly reach the temperature at which the thermally expandable particles expand. above temperature. Therefore, the selective peeling of the object to be processed and inspected can be performed more quickly.

The adhesive sheet used in the heat-peeling method of processing an inspection object according to this embodiment contains heat-expandable particles in a heat-expandable substrate instead of an adhesive layer for attaching an inspection object. When heat-expandable particles are included in the adhesive for attaching the object to be processed and inspected, residues from the heat-expandable particles may adhere to the surface of the object to be processed and inspected, making it impossible to clean the surface of the object to be inspected. Also, when the heat-expandable particles are foamed or expanded by heating, since the adhesive layer is greatly deformed, there may be a concern that adhesive residue may occur on the surface of the processed inspection object after heat-peeling. On the other hand, in the adhesive sheet of this embodiment, since the heat-expandable particle system is contained in the heat-expandable base material, the object to be processed and inspected attached to the adhesive surface of the adhesive layer does not directly contact the heat-expandable particle system. . Therefore, if the residue from the heat-expandable particles and a part of the greatly deformed adhesive layer are prevented from adhering to the surface of the processed inspection object, the cleanliness of the processed inspection object surface after heat peeling and the suppression of residual adhesive can be achieved, and at the same time Among the plurality of process inspection objects attached to the adhesive sheet, a desired part can be selectively heated and peeled off. Hereinafter, the storage modulus and thickness of the heat-expandable base material, the storage shear modulus and thickness of the adhesive layer (X1), and the heat-expandable base material will be described in detail with respect to the heat-peeling method of the object to be inspected according to the present embodiment. The preferred range of the relationship between the thickness of the adhesive layer (X1) and the thickness of the adhesive layer (X1).

(Storage modulus and thickness of thermally expandable base material) The storage modulus E'(23) of the thermally expandable base material of the adhesive sheet of this embodiment at 23°C is preferably 1.0×10 ⁶ Pa or more, more preferably 5.0×10 ⁶ to 5.0×10 ¹² Pa, more preferably 1.0×10 ⁷ to 1.0×10 ¹² Pa, even more preferably 5.0×10 ⁷ to 1.0×10 ¹¹ Pa, most preferably 1.0×10 ⁸ to 1.0 ×10 ¹⁰ Pa. Hereinafter, the said range of the storage modulus E'(23) in 23 degreeC is called requirement (1). By using a thermally expandable base material that satisfies the above requirement (1), it is possible to suppress the positional deviation of the processing inspection object when the processing inspection object is placed and attached to the adhesive sheet. In addition, it is possible to suppress sinking of the processing inspection object into the adhesive layer (X1) when the processing inspection object is placed and attached to the adhesive sheet, and good peelability can be ensured. For example, well-known devices, such as a flip-chip bonder and a die bonder, may be used for placing the object to be processed and inspected on the adhesive layer (X1) of the adhesive sheet. Using such an apparatus, when the object to be processed and inspected is placed on the adhesive layer (X1) of the adhesive sheet, a pressing force is applied to the object to be processed and inspected in the thickness direction of the adhesive sheet. For this reason, there exists a possibility that the object to be inspected may sink too much in the thickness direction of the adhesive layer (X1). In addition, when using such a device, when the object to be inspected is placed on the adhesive sheet, since the force to move the object to be inspected in the horizontal direction of the adhesive sheet is also applied, the object to be inspected is also placed on the adhesive layer. The risk of positional shift in the horizontal direction. Furthermore, due to the own weight of the processed inspection object, there is also a possibility that the processed inspection object may sink too much on the thickness direction side of the adhesive layer (X1). These problems can be solved by using a thermally expandable substrate satisfying the above requirement (1). In addition, in this specification, the storage modulus E' of the thermally expandable base material in a specific temperature means the value measured by the method described in the Example.

In addition, the storage modulus E'(100) of the heat-expandable base material of the adhesive sheet of this embodiment at 100°C is preferably at least 2.0×10 ⁵ Pa, more preferably at least 4.0×10 ⁵ Pa, and most preferably It is at least 6.0×10 ⁵ Pa, more preferably at least 8.0×10 ⁵ Pa, and most preferably at least 1.0×10 ⁶ Pa. Also, the storage modulus E'(100) at 100°C is preferably at most 1.0×10 ¹² Pa, more preferably at most 1.0×10 ¹¹ Pa, even more preferably at most 1.0×10 ¹⁰ Pa, even more preferably at most 1.0×10 10 Pa Below 10 ⁹ Pa. Hereinafter, the said range of the storage modulus E'(100) in 100 degreeC is called requirement (2). By using a heat-expandable base material satisfying the above-mentioned requirement (2), positional displacement of the adhesive sheet can be suppressed during heating of a part of the adhesive sheet to a temperature above which thermally-expandable particles expand. In addition, in the process of heating a part of the adhesive sheet to a temperature higher than the temperature at which the thermally expandable particles expand, it is possible to suppress the intrusion of the object to be processed and inspected into the adhesive layer (X1), ensuring good peelability. In general, since the thermally expandable adhesive layer of the adhesive sheet described in Patent Document 1 contains an adhesive resin, the storage modulus E' tends to decrease significantly as the temperature rises. Here, when the degree of decrease in the storage modulus E' of the heat-expandable adhesive layer becomes very large, the heat-expandable particles and the adhesive resin contained in the heat-expandable adhesive layer become easy to flow, and the heat-expandable adhesive The adhesive surface of the layer is easily deformed. As a result, in the process of heating a part of the adhesive sheet to a temperature higher than the temperature at which the thermally expandable particles expand, positional displacement of the processed inspection object is likely to occur. In addition, the object to be inspected during processing may sink into the side of the adhesive sheet, and there may be a problem that the object to be inspected during processing becomes difficult to peel off. These problems can be solved by using a thermally expandable base material satisfying the above requirement (2).

In addition, the storage modulus E'(t) of the heat-expandable base material system t°C of the adhesive sheet of this embodiment is preferably 1.0×10 ⁷ Pa or less, more preferably 9.0×10 ⁶ Pa or less, and most preferably It is 8.0×10 ⁶ Pa or less, more preferably 6.0×10 ⁶ Pa or less, and most preferably 4.0×10 ⁶ Pa or less. In addition, "t" is the expansion start temperature of a heat-expandable particle, Here, it is 120-250 degreeC. Hereinafter, the said range of the storage modulus E'(t) in t degreeC is called requirement (3). Since the heat-expandable base material satisfies the requirement (3), the heat-expandable base material is easily deformed following the volume expansion of the heat-expandable particles at the temperature at which the heat-expandable particles are expanded, and the adhesive layer (X1) becomes easy. Thereby, the releasability of the processed inspection target object from the adhesive sheet can be made more excellent. Also, from the viewpoint of suppressing the flow of the expanded heat-expandable particles, improving the shape retention of the unevenness formed on the adhesive surface of the adhesive layer (X1), and further improving the peelability, the storage mold of the heat-expandable base material The number E'(t) is preferably at least 1.0×10 ³ Pa, more preferably at least 1.0×10 ⁴ Pa, and most preferably at least 1.0×10 ⁵ Pa.

The thickness of the heat-expandable substrate included in the adhesive sheet of this embodiment is preferably 10-1000 μm, more preferably 20-500 μm, particularly preferably 25-400 μm, and still more preferably 30-300 μm. In addition, in this specification, the thickness of a heat-expandable base material means the value measured by the method described in an Example.

(Storage shear modulus and thickness of adhesive layer (X1)) In the adhesive sheet of this embodiment, the storage shear modulus G'(23) of the adhesive layer (X1) at 23°C is preferably 1.0 ×10 ⁴ to 1.0×10 ⁸ Pa, more preferably 5.0×10 ⁴ to 5.0×10 ⁷ Pa, most preferably 1.0×10 ⁵ to 1.0×10 ⁷ Pa. If the storage shear modulus G'(23) of the adhesive layer (X1) is 1.0×10 ⁴ Pa or more, it is possible to prevent the positional deviation of the processing inspection object and prevent the processing inspection object from moving to the adhesive layer. (X1) fall into. On the other hand, if the storage shear modulus G'(23) of the adhesive layer (X1) is 1.0×10 ⁸ Pa or less, unevenness caused by the expanded thermally expandable particles is likely to be formed on the adhesive surface, resulting in It is easy to peel off the object to be processed and inspected. In addition, in this specification, the storage shear modulus G'(23) of an adhesive layer (X1) means the value measured by the method described in an Example.

In addition, the thickness of the adhesive layer (X1) is from the viewpoint of exhibiting excellent adhesive force and the viewpoint of easy formation of unevenness on the surface of the adhesive layer due to the expansion of the thermally expandable particles in the thermally expandable substrate due to heat treatment. In terms of thickness, it is preferably from 1 to 60 μm, more preferably from 2 to 50 μm, especially preferably from 3 to 40 μm, and even more preferably from 5 to 30 μm. The thermally expandable adhesive layer of the adhesive sheet described in Patent Document 1 requires a certain thickness in order to sufficiently contain thermally expandable particles. Therefore, the position of the object to be processed and inspected may be shifted, or the object to be processed and inspected may fall into the side of the adhesive sheet. In contrast, the adhesive sheet of this embodiment is based on the adjustment of the thickness of the adhesive layer (X1) on which the semiconductor chip is placed, the adhesive force and the The degrees of freedom in the control of the viscoelastic modulus and the like are increased. This suppresses the occurrence of positional displacement of the semiconductor wafer and suppresses the semiconductor wafer from being caught in the adhesive sheet.

(Relationship between the thickness of the heat-expandable base material and the thickness of the adhesive layer (X1)) In the adhesive sheet of this embodiment, from the viewpoint of exhibiting better peelability, the thickness of the heat-expandable base material at 23°C The ratio to the thickness of the adhesive layer (thermally expandable base material/adhesive layer) is preferably at least 0.2, more preferably at least 0.5, particularly preferably at least 1.0, even more preferably at least 5.0. Moreover, it is preferably 1,000 or less, more preferably 200 or less, particularly preferably 60 or less, and still more preferably 30 or less.

(Steps (I-1) to (I-2)) In the heat-peeling method of the processed inspection object of this embodiment, the plurality of processed inspection objects can also be attached to the processed inspection object before individual pieces It is temporarily fixed by sticking thin sheets, and cut into individual sheets. That is, step (I) may have the following steps (I-1) to (I-2), Step (I-1): sticking a sheet on the adhesive surface of the adhesive layer (X1) of the aforementioned adhesive sheet Step (I-2) of processing and inspecting the object before slicing, Step (I-2): the step of individualizing the processing and inspection object before slicing which is attached to the aforementioned adhesive surface, in step (I-1) Among them, the processing and inspection objects attached to the adhesive sheet before individualization are, for example, silicon wafers or FPC parts. In addition, in step (I-2), the method of individualizing the processed inspection object before individualization is not particularly limited, for example, it is implemented by cutting means such as a dicing saw. Alternatively, the processing inspection object having grooves formed on the front side of the processing inspection object along the planned division line may be attached so that the front side contacts the adhesive surface of the adhesive sheet, and the processing inspection object may be attached from the back side of the processing inspection object to the surface of the adhesive sheet. At least until the groove is reached, thinning processing such as grinding of the processed inspection object is performed, and the processed inspection object is divided into individual pieces by the so-called "cut first method". In addition, stealth cutting (registered trademark) can also be used to form a modified area inside the processed inspection object, and then attached in such a way that the front side of the processed inspection object contacts the adhesive surface of the adhesive sheet, from the back of the processed inspection object Grinding is performed to thin the processed inspection object, and by applying external force such as pressure, the processed inspection object is divided into individual pieces. Furthermore, it is also possible to expand the adhesive sheet attached with the individualized processed inspection objects to arbitrarily expand the interval between the individualized processed inspection objects. In addition, the individualization and expansion of the processed inspection object can be performed simultaneously. In addition, the processing and inspection objects that have been individually sliced through steps (I-1) to (I-2) or the processing and inspection objects that have been further expanded can be directly supplied to step (II), or can be processed after further processing. After at least one of processing and inspection, it is supplied to step (II).

(Steps (I-A1)~(I-A3), Steps (I-B1)~(I-B3)) In the heat peeling method for processing inspection objects in this embodiment, it is preferable to process a plurality of inspection objects It is a package in which a plurality of semiconductor chips obtained in the semiconductor packaging process are packaged in a packaging material, and the package is divided into pieces in units of semiconductor chips. That is, in the heat-peeling method of processing the inspection object according to this embodiment, it is preferable to continuously process the packaging of a plurality of semiconductor chips through the packaging material on the same above-mentioned adhesive sheet, and the semiconductor wafer unit of the package. Slicing and selective thermal debonding of packages that have been singulated in semiconductor wafer units.

In recent years, miniaturization, weight reduction, and high-performance of electronic equipment have progressed. Along with this, semiconductor devices mounted on electronic equipment have also been required to be miniaturized, thinned, and high-density. FOWLP (Fan out Wafer Level Package) and FOPLP (Fan out Panel Level Package) are attracting attention as semiconductor packages that can meet such demands. In the manufacturing process of FOWLP and FOPLP, the packaging material is used to cover the semiconductor chip in such a way that the area is larger than the size of the chip, so as to form the package of the semiconductor chip (hereinafter also referred to as the "package"), not only the semiconductor chip The circuit surface of the package, and in the surface area of the package, the redistribution layer and external electrodes are also formed.

However, in the manufacturing process of semiconductor packages represented by FOWLP and FOPLP, a mounting step of mounting a plurality of semiconductor chips on an adhesive sheet for temporary fixing (hereinafter also referred to as "sheet for temporary fixing") is included. , a coating step of coating with a sealing material that is given fluidity by heating, and a hardening step of thermally curing the sealing material. Through these steps, a package is formed. For the temporary fixing sheet used in the manufacture of the semiconductor package, it is required that the position of the semiconductor wafer does not shift between the above-mentioned coating step and the hardening step (hereinafter, these are also referred to as "packaging steps"), and Adhesiveness to the extent that the encapsulating material does not enter the bonding interface between the semiconductor wafer and the temporary fixing sheet. Also, after the encapsulation step, peelability that can be easily removed without residue is required. That is, the temporary fixing sheet used in the manufacture of a semiconductor package is required to have both adhesiveness at the time of use (at the time of temporary fixing) and peelability after use.

Here, for example, in the manufacturing process of FOWLP and FOPLP, after the packaging step, it generally goes through a separation step of peeling off the package body from the temporary fixing sheet, and forming a rewiring layer on the surface of the semiconductor chip side of the package body. The wiring layer forming step and the cutting step of cutting the package on which the rewiring layer is formed into individual semiconductor wafers are used to manufacture FOWLP and FOPLP. However, in the manufacturing process of FOWLP and FOPLP, modifications of the above-mentioned general steps are also considered. For example, after the packaging step, it is also conceivable not to separate the package from the temporary fixing sheet, but to cut and separate the package in units of semiconductor wafers (hereinafter also referred to as "package singulation step"), and only Some of the individualized packages are selectively peeled and separated from the temporary fixing sheet (Modification 1). In Modification 1, the step of forming the rewiring layer is, for example, performed after the packaging step and before the package singulation step (Modification 1a). In addition, the rewiring layer forming step is performed, for example, after the package singulation step and before the singulated packages are selectively peeled off from the temporary fixing sheet (modification 1b). Alternatively, the rewiring layer forming step is performed, for example, after selectively peeling the individualized package from the temporary fixing sheet (modification 1c). According to these modified examples 1a to 1c, among the individualized packages, only the package including the desired semiconductor chip can be selectively peeled off from the temporary fixing sheet and recovered. Also, only the package including the desired semiconductor chip may remain in a state attached to the temporary fixing sheet, and the other packaging systems may be peeled off and recycled. For example, when there is a mixture of packages including a plurality of semiconductor chips with different wiring patterns, only the packages including semiconductor chips of a certain wiring pattern can be selectively removed from the adhesive sheet or remain on the adhesive sheet. superior. In addition, in the case of the modified examples 1a and 1b, in the rewiring layer forming step, the defect in the wiring can be selectively removed from the adhesive sheet or left on the adhesive sheet. And these are not only applicable to the manufacturing process of FOWLP and FOPLP, but also applicable to the manufacturing process of other semiconductor packages.

Therefore, it is also considered to use the adhesive sheet described in Patent Document 1 as a temporary fixing sheet in the packaging step and package individualization step in the manufacturing process of semiconductor packaging. However, according to the examination of the inventors of the present invention, when the adhesive sheet described in Patent Document 1 is used as the temporary fixing sheet, the elastic modulus of the thermally expandable adhesive layer decreases due to the heating in the sealing step, and the mounted The semiconductor wafer is sunk into the side of the adhesive sheet. In addition, it was found that the positional displacement of the semiconductor wafer occurred in the mounting step and the packaging step described above. Because of this, in the surface of the package on the semiconductor chip side, a step difference occurs between the surface of the semiconductor chip and the surface of the package, resulting in poor flatness or a decrease in the positional accuracy of the semiconductor chip. Such a decrease in the flatness of the surface of the semiconductor chip side of the package and a decrease in the positional accuracy of the semiconductor chip may lead to defects in subsequent steps. For example, when a rewiring layer is formed on the surface of the package on the semiconductor wafer side, a decrease in rewiring precision or the like may occur. Therefore, it is desirable to suppress a decrease in the flatness of the surface of the package on the semiconductor chip side and a decrease in the positional accuracy of the semiconductor chip. Also, when the package is peeled off from the adhesive sheet, heating is also performed to expand the heat-expandable adhesive layer, and since the semiconductor chip is sunk into the side of the adhesive sheet, if there is no external force of a certain magnitude, the individualized package will be separated. Peeling becomes difficult. Furthermore, as mentioned above, when using the adhesive sheet described in Patent Document 1 as a temporary fixing sheet, since the adhesive layer contains thermally expandable particles, there are residues from the thermally expandable particles and/or the adhesive layer, which may cause contamination. Concerns about processing and inspecting the surface of the object after heat peeling. In addition, the uneven shape on the surface of the adhesive layer formed by the heat-expandable particles is transferred to the surface of the package on the semiconductor chip side, and there is also a concern that the smoothness may be lowered.

For these problems, by using the same adhesive sheet having a heat-expandable base material containing heat-expandable particles, encapsulation of a semiconductor chip by means of an encapsulation material, singulation of packages, and singulated packages are successively processed Selective thermal peeling, to suppress the occurrence of positional deviation of the semiconductor chip, while ensuring the flatness of the surface of the semiconductor chip side of the package, can make the rewiring accuracy and the peelability of the package from the adhesive sheet become good, Furthermore, an extremely excellent effect of selectively heating and peeling off the individualized packages is achieved. Hereinafter, steps (I-A1) to (I-A3) and steps (I-B1) to (I-B3) of attaching the individualized package to the adhesive sheet will be described in detail.

(Steps (I-A1)~(I-A3))

When the individualized package is attached to the double-sided adhesive sheet, the step (I) has the following steps (I-A1)~(I-A3), for example, step (I-A1): a plurality of semiconductor chips are placed on the Step (I-A2): Covering the plurality of semiconductor chips and the plurality of semiconductor chips with a package material while providing a gap between the adjacent semiconductor chips and placing them on the adhesive surface of the adhesive layer (X1) The step of hardening the packaging material on the adhesive surface of the peripheral portion of the chip to obtain a package in which the plurality of semiconductor chips are packaged in the hardened packaging material, step (I-A3): packaging the package body in units of the semiconductor chip Fragmentation steps.

Hereinafter, each step will be described with reference to the drawings.

In steps (I-A1) to (I-A3), as shown in FIG. 7(a), a double-sided adhesive sheet 2a with a hard support 14 attached to the adhesive surface of the adhesive layer (X2) is used. In this way, the double-sided adhesive sheet is supported by the hard support and kept in a flat state. Therefore, a package excellent in flatness can be obtained. In addition, the double-sided adhesive sheet is also excellent in handleability, and a semiconductor chip can be easily mounted on the double-sided adhesive sheet. Furthermore, the composition, material and thickness of the hard support are as above.

A sectional view is shown in FIG. 7( b ), which illustrates a step (I- A1).

In addition, when the double-sided adhesive sheet 2a has the release material 131, the release material 131 is peeled off in advance.

As the semiconductor chip CP, known ones can be used. On the circuit surface W1 of the semiconductor chip CP, an integrated circuit composed of circuit elements such as transistors, resistors, and capacitors is formed. Furthermore, the semiconductor chip CP is not limited to a single-layer structure, and can also be used as a laminated body of semiconductor chips laminated with two or more layers to manufacture a chip multi-stage laminate package.

The semiconductor chip CP is placed such that the circuit surface W1 thereof is covered with the adhesive surface 121 a of the adhesive layer ( X1 ) 121 , for example. Well-known devices, such as a flip chip bonder and a die bonder, can be used for mounting of the semiconductor wafer CP.

Here, the plurality of semiconductor chips CP are preferably placed on the adhesive surface 121a of the adhesive layer (X1) 121 in a state of being aligned at a certain interval, and more preferably, the plurality of semiconductor chips CP are arranged at a certain interval. They are placed on the adhesive surface 121a of the adhesive layer (X1) 121 in a state of being aligned in a matrix of plural rows and plural columns at intervals. The distance between the semiconductor chips CP can be appropriately determined according to the intended packaging form and the like.

Figure 7(c) and (d) show cross-sectional views, which illustrate that a plurality of semiconductor chips CP and the adhesive surfaces 30 of the peripheral portions of the plurality of semiconductor chips CP are covered with a package material 40, and the package material 40 is hardened to obtain a plurality of semiconductor chips CP. The step (I-A2) of sealing the semiconductor chip CP in the package body 50 which hardened the sealing material 41.

Furthermore, the step of covering the plurality of semiconductor chips CP and the adhesive surfaces 30 of the peripheral portions of the plurality of semiconductor chips CP with the packaging material 40 may also be referred to as a "coating step" in the following, and the packaging material 40 may be hardened. get The step in which the semiconductor chip CP is packaged in the package body 50 formed by the hardened packaging material 41 is referred to as a "hardening step".

As shown in FIG. 7( c ), in the covering step, first, the plurality of semiconductor chips CP and the adhesive surfaces 30 of the peripheral portions of the plurality of semiconductor chips CP are covered with the packaging material 40 . The package material 40 covers the entire exposed surfaces of the plurality of semiconductor chips CP, and also fills the gap between the semiconductor chips CP.

The packaging material 40 has the function of protecting the plurality of semiconductor chips CP and the elements accompanying them from the external environment.

The encapsulant 40 is not particularly limited, and any one can be appropriately selected from conventional semiconductor encapsulant users and used.

The sealing material 40 is curable from the viewpoint of mechanical strength, heat resistance, insulation, etc., and examples thereof include thermosetting resin compositions, energy ray-curing resin compositions, and the like.

Hereinafter, in this embodiment, it will be described that the package material 40 is a thermosetting resin composition.

Examples of the thermosetting resin contained in the thermosetting resin composition of the package 40 include epoxy resin, phenol resin, cyanate resin, etc. From the standpoint of this, epoxy resin is preferable.

The above-mentioned thermosetting resin composition may contain, in addition to the above-mentioned thermosetting resin, curing agents such as phenolic resin-based curing agents and amine-based curing agents, curing accelerators, inorganic fillers such as silica, and elastic resins. Body and other additives.

The packaging material 40 is solid at room temperature, and may also be liquid. Moreover, the form of the encapsulating material 40 that is solid at room temperature is not particularly limited, for example, it may be in the form of granules, flakes, and the like.

As a method of covering the plurality of semiconductor chips CP and the adhesive surfaces 30 of the peripheral portions of the plurality of semiconductor chips CP with the packaging material 40, any method can be appropriately selected from conventional methods applicable to semiconductor packaging steps and applied. , For example, a roll lamination method, a vacuum press method, a vacuum lamination method, a spin coating method, a die coating method, a transfer molding method, and a compression molding method can be applied.

In these methods, generally, in order to improve the fillability of the encapsulating material 40, the encapsulating material 40 is heated at the time of coating to impart fluidity.

Furthermore, the encapsulation step is carried out at a temperature lower than the expansion start temperature (t) of the heat-expandable particles.

As shown in FIG. 7( d ), after the coating step is performed, the encapsulant 40 is cured to obtain a package 50 in which a plurality of semiconductor chips CP are encapsulated in the cured encapsulant 41 . Furthermore, the coating treatment and thermosetting treatment of the packaging material 40 can be performed separately, but when the packaging material 40 is heated during the coating treatment, the packaging material 40 can be directly hardened by the heating, and the coating treatment and thermal curing treatment can be performed simultaneously. Hardened.

Here, as described above, the double-sided adhesive sheet 2a used in this embodiment has a thermally expandable substrate 11 containing thermally expandable particles, and in step (II), the adhesive layer is lowered by expanding the thermally expandable particles. (X1) The contact area between the adhesive surface 121a of 121 and the package body 50 reduces the adhesive force, and the package body 50 is separated from the double-sided adhesive sheet 2a by peeling off. Therefore, in the coating step and the hardening step, it is preferable to suitably select conditions under which the heat-expandable particles do not expand, and to coat and harden the sealing material 40 . For example, the heating conditions (heating temperature and heating time) in the coating step and the hardening step are preferably heating conditions in which the increase rate of the thickness of the double-sided adhesive sheet 2a caused by the expansion of the thermally expandable particles is 10% or less, more preferably It is a heating condition in which the aforementioned increase rate is 5% or less, particularly preferably a heating condition in which the aforementioned increase rate is 0% (that is, a heating condition in which the heat-expandable particles do not expand). Furthermore, the increase rate of the thickness of the double-sided adhesive sheet 2a can be measured under specific conditions using a constant pressure thickness measuring device (manufactured by TECLOCK Co., Ltd., product name "PG-02"), for example, in accordance with JIS K6783, Z1702, and Z1709. The thickness of the double-sided adhesive sheet 2a before and after heating is calculated according to the following formula. Thickness increase rate (%)=(thickness after heating-thickness before heating)×100/thickness before heating In addition, the coating step and the hardening step can also be performed separately, but when the sealing material 40 is heated in the coating step, The sealing material 40 can be hardened directly by this heating. That is, at this time, the coating step and the hardening step may be performed simultaneously.

Specific examples of the temperature for heating the thermosetting resin composition in the aforementioned covering step also vary depending on the type of the package material 40 to be used, the type of thermally expandable particles, etc., but it is, for example, 30 to 180°C, preferably 50-170°C, more preferably 70-150°C. Also, the heating time is, for example, 5 seconds to 60 minutes, preferably 10 seconds to 45 minutes, more preferably 15 seconds to 30 minutes. In the aforementioned curing step, specific examples of the temperature for curing the encapsulant 40 also vary depending on the type of the encapsulant 40 used, the type of thermally expandable particles, etc., but are, for example, 80 to 240° C., preferably 90° C. ~200°C, more preferably 100-170°C. Also, the heating time is, for example, 10 to 180 minutes, preferably 20 to 150 minutes, more preferably 30 to 120 minutes.

Here, in this embodiment, it is preferable to use a sheet-shaped packaging material (hereinafter, also referred to as "sheet-shaped packaging material"), and to implement the coating step and the hardening step. In the method of using a sheet-shaped package, the sheet-shaped package is placed so as to cover the plurality of semiconductor chips CP and the adhesive surfaces 30 of the peripheral portions of the plurality of semiconductor chips CP, and is covered by the package 40 . At that time, in the gap between the semiconductor chips CP, it is preferable to heat and press-bond the gaps between the semiconductor chips CP by vacuum lamination or the like so that no portion not filled with the encapsulation material 40 occurs. Then, the laminated encapsulation material 40 is heated and cured. A preferred aspect of the curing temperature is as described above. The sheet-shaped packaging material can be a laminated sheet supported by a resin sheet such as polyethylene terephthalate. At this time, the resin sheet can be peeled off from the packaging material 40 after the sheet-shaped packaging material is placed so as to cover the adhesive surfaces 30 of the plurality of semiconductor chips CP and the peripheral portions of the plurality of semiconductor chips CP.

Through the step (I-A2), a package body 50 in which a plurality of semiconductor chips CP are embedded in the hardened package material 41 separated by a predetermined distance is obtained.

FIG. 7( e ) shows a cross-sectional view illustrating a step of chipping 50 packages in units of semiconductor wafers CP. In step (I-A3), 50 packages are sliced into semiconductor wafer CP units. The method of cutting the package into 50 pieces is not particularly limited, and it can be implemented by cutting means such as a dicing saw or the like.

By slicing 50 packages, the singulated packages 50a of the semiconductor chip CP unit are obtained. Thereby, on the double-sided adhesive sheet 2a, it will be in the state in which the several package body 50a which separated into pieces was attached as the object to be processed and inspected.

Here, in the above-mentioned embodiments of steps (I-A1) to (I-A3), the description of the rewiring layer forming step is omitted, but when the rewiring layer is formed, the rewiring layer forming step can be performed, for example, in the step ( Implemented between I-A2) and (I-A3) or after step (I-A3).

When rewiring is formed without peeling the package from the adhesive sheet, the rewiring layer is formed on the side of the semiconductor wafer opposite to the surface to which the adhesive sheet is attached (hereinafter also referred to as "package front side"). When forming the rewiring layer on the front side of the package, the package is produced in a state where the metal terminal electrodes on the circuit surface W1 of the semiconductor chip are routed from the circuit surface W1 through the periphery of the semiconductor chip toward the front side of the package. Then, after the package is formed, the package is ground from the front side of the package to expose the metal terminal electrodes, and a rewiring layer is formed so as to be in contact with the exposed metal terminal electrodes. However, it is not necessary to be limited to such a method. For example, in step (I-A1), the semiconductor wafer is placed in such a way that the surface of the semiconductor wafer opposite to the circuit surface W1 is in contact with the adhesive surface of the adhesive sheet, and the semiconductor wafer on the circuit surface W1 The metal terminal electrodes have a certain thickness (thickness in the vertical direction with respect to the surface of the semiconductor wafer). Then, similarly to the above, after the package is formed, the package is ground from the front side of the package to expose the metal terminal electrodes, and the rewiring layer may be formed so as to be in contact with the exposed metal terminal electrodes.

(Steps (I-B1)~(I-B3))

When the individualized package is attached to the single-sided adhesive sheet, the step (I) includes, for example, the following steps (I-B1) to (I-B3). Furthermore, the frame member used in the step (I-B1) is the same as the "frame member 20" described in the aforementioned [step (I)], and has one or more openings 21 that penetrate through the holes on the front and back.

Step (I-B1): a step of placing a plurality of semiconductor wafers on the adhesive surface of the adhesive layer (X1) exposed in the opening of the frame member while providing a gap between the adjacent semiconductor wafers , step (I-B2): coating the aforementioned plurality of semiconductor chips and the adhesive surfaces of the peripheral portions of the aforementioned plurality of semiconductor chips and the adhesive surfaces of the aforementioned gaps with an encapsulation material, and hardening the aforementioned encapsulation material to obtain the aforementioned plurality of semiconductor chips packaged In the step of hardening the package to form the package, step (I-B3): a step of singulating the package in units of the semiconductor wafer.

Hereinafter, each step will be described with reference to the drawings.

In steps (I-B1)~(I-B3), as shown in FIG. 8(a), the frame member 20 with the opening 21 formed on the adhesive surface 121a of the adhesive layer (X1) 121 is attached. A single-sided adhesive sheet 1a. Thereby, the single-sided adhesive sheet is supported by the frame member and kept in a flat state. Therefore, a package excellent in flatness can be obtained. In addition, the single-sided adhesive sheet is also excellent in handleability, and a semiconductor chip can be easily mounted on the single-sided adhesive sheet. Furthermore, the composition and material of the frame members are as above.

Furthermore, the thickness of the frame member used in steps (I-B1) to (I-B3) is as mentioned above, for example, 100 μm-3 mm, more preferably 100 μm-1 mm, especially 100-500 μm. When the thickness of the frame member is 100 μm or more, warpage of the package can be suppressed even when a relatively wide area is packaged. When the thickness of the frame member is 3 mm or less, it is possible to prevent the productivity of the package from being lowered.

Step (I-B1) is shown in FIG. 8(b), step (I-B2) is shown in FIG. 8(c) and FIG. 8(d), and step (I-B3) is shown in FIG. 8(e). The difference between steps (I-B1)~(I-B3) and steps (I-A1)~(I-A3) is that in step (I-B1), the adhesive exposed at the opening of the frame member On the adhesive surface of the layer (X1), a gap is provided between the adjacent semiconductor wafers, and a plurality of semiconductor wafers are placed at the same time, and the others are common. Therefore, regarding this common part, it can implement in the aspect similar to the aspect demonstrated in process (I-A1) - (I-A3). Also, similar to the above-mentioned embodiment of steps (I-A1) to (I-A3), when forming the rewiring layer, the rewiring layer forming step is, for example, between steps (I-B2) and (I-B3). Occasionally performed after step (I-B3). Alternatively, it is implemented for the packages selectively peeled off through the step (II).

The adhesive sheet of this embodiment is used in the process of semiconductor packaging in the form of steps (I-A1)-(I-A3) or steps (I-B1)-(I-B3), which can solve the following problems: The position of the semiconductor chip is shifted between the mounting step and the packaging step of the semiconductor chip, or the semiconductor chip is caught on the side of the adhesive sheet, and the surface of the semiconductor chip side of the package cannot be flattened. That is, since the adhesive sheet of this embodiment contains thermally expandable particles in a non-adhesive base material with a high modulus of elasticity, the adjustment of the thickness of the adhesive layer (X1) on which the semiconductor chip is placed, the adhesive force and the viscoelastic modulus The degree of freedom of control etc. is increased. Thereby, occurrence of misalignment of the semiconductor chip can be suppressed, and sinking of the semiconductor chip into the adhesive sheet can be suppressed, so that a package excellent in flatness of the surface on the semiconductor chip side can be formed. In addition, in the adhesive sheet of this embodiment, since the semiconductor chip is mounted on the adhesive surface of the adhesive layer (X1), the heat-expandable base material does not directly contact the surface of the semiconductor chip side of the package. Thereby, it is possible to prevent residues from heat-expandable particles and part of the greatly deformed adhesive layer from adhering to the surface of the package on the semiconductor wafer side, or to transfer the unevenness formed in the heat-expandable adhesive layer to the semiconductor of the package. The smoothness of the surface on the chip side is reduced; the cleanliness and smoothness of the surface of the semiconductor chip side of the package can be improved.

Also, when the adhesive sheet of this embodiment is used in the manufacturing process of semiconductor packaging, such as steps (I-A1) to (I-A3) or steps (I-B1) to (I-B3), since the use satisfies the above requirements The thermally expandable base material of (1) can more reliably prevent the positional deviation of the processing and inspection objects such as semiconductor chips, and can also more reliably prevent the processing and inspection objects such as semiconductor chips from moving toward the adhesive layer (X1). fall into. Also, due to the use of a thermally expandable base material that satisfies the above requirement (2), even in the manufacturing process of semiconductor packaging, for example, in the temperature environment of the packaging step of the manufacturing process of fan-out packaging such as FOWLP and FOPLP, it can be properly suppressed. The heat-expandable particles flow, so the adhesive surface of the adhesive layer (X1) disposed on the heat-expandable base material is not easily deformed. As a result, the displacement of the semiconductor chip in the packaging step can be more reliably prevented, and at the same time, the sinking of the semiconductor chip into the adhesive layer (X1) can be prevented more reliably. Furthermore, since the ratio of the thickness of the thermally expandable base material to the thickness of the adhesive layer (X1) at 23°C (thermally expandable base material/adhesive layer (X1)) is within the above-mentioned range, the semiconductor of the package can be made The surface on the wafer side becomes flatter, and at the same time, positional displacement of the semiconductor wafer can be more reliably prevented.

Furthermore, in step (I), when the process inspection target object (package) is separated into pieces on the adhesive sheet as described above, it can be done after the process inspection target object (package body) is completely separated into pieces. , implementing step (II), it is also possible to carry out step (II) sequentially while performing individualization of the processed inspection object (package body), and recover the individualized processed inspection object (package body).

Here, in this embodiment, after the packaging step, the entire adhesive sheet may be heated, the package may be peeled off, and then the package may be attached to a new adhesive sheet, and the rewiring layer forming step may be performed on the package. The wafer unit is cut and singulated, and step (II) is performed to selectively peel and separate only a part of the singulated packages from the above-mentioned adhesive sheet. At this time, by using the above-mentioned adhesive sheet at the time of the packaging step, the occurrence of positional displacement of the semiconductor chip can be suppressed, and at the same time, the sinking of the semiconductor chip into the adhesive sheet can be suppressed, and the side surface of the semiconductor chip can be formed while being excellent in flatness. package while performing selective peeling of the package.

Next, each constituent material and the like of the adhesive used in the present invention will be described in detail below.

[Heat-expandable base material] The heat-expandable base material is a non-adhesive base material containing resin and heat-expandable particles.

In the present invention, the judgment of whether the thermally expandable substrate is a non-adhesive substrate is based on the probe viscosity value measured in accordance with JIS Z0237: 1991 on the surface of the target substrate, as long as it does not reach 50mN/5mmφ, Then the substrate is judged as "non-adhesive substrate". Here, the probe viscosity value of the surface of the heat-expandable substrate is usually less than 50mN/5mmφ, preferably less than 30mN/5mmφ, more preferably less than 10mN/5mmφ, and most preferably less than 5mN/5mmφ. Furthermore, in this specification, the specific measurement method of the probe viscosity value on the surface of the heat-expandable substrate follows the method described in the examples.

The heat-expandable base material contains resin and heat-expandable particles, but may also contain additives for base materials as needed within the range that does not impair the effect of the present invention. In addition, the heat-expandable base material can be formed of a resin composition (y) containing a resin and heat-expandable particles. Hereinafter, each component contained in the resin composition (y) of the forming material of the heat-expandable base material will be described.

[Resin] The resin contained in the resin composition (y) is not particularly limited as long as the thermally expandable base material becomes non-adhesive, and may be a non-adhesive resin or an adhesive resin. That is, even if the resin contained in the resin composition (y) is an adhesive resin, as long as the adhesive resin and the polymerizable compound are polymerized during the process of forming the thermally expandable substrate from the resin composition (y), The obtained resin becomes a non-adhesive resin, and the heat-expandable base material containing this resin should just become non-adhesive.

The mass average molecular weight (Mw) of the resin contained in the resin composition (y) is preferably from 10 million to 1 million, more preferably from 10 million to 700,000, and especially preferably from 10 million to 500,000. Also, when the resin is a copolymer having two or more constituent units, the form of the copolymer is not particularly limited, and may be any of block copolymer, random copolymer and graft copolymer.

The content of the aforementioned resin is preferably from 50 to 99% by mass, more preferably from 60 to 95% by mass, particularly preferably from 65 to 90% by mass, relative to the total amount (100% by mass) of active ingredients of the resin composition (y), Especially more preferably, it is 70-85 mass %.

As said resin contained in resin composition (y), it is preferable to contain 1 or more types selected from the urethane-acrylic resin and an olefin resin. Also, the above-mentioned urethane acrylate resin is preferably the following resin (U1).・Acrylic urethane resin (U1) made by polymerizing urethane prepolymer (UP) and vinyl compound containing (meth)acrylate.

(Urethane Acrylic Resin (U1)) As the urethane prepolymer (UP) serving as the main chain of the urethane acrylic resin (U1), polyhydric alcohols and polyhydric Reactant of isocyanate. Furthermore, the urethane prepolymer (UP) is preferably obtained by further applying a chain extension reaction using a chain extender.

Examples of polyols used as raw materials for urethane prepolymers (UP) include alkylene polyols, ether polyols, ester polyols, esteramide polyols, ester Ether polyols and carbonate polyols, etc. These polyols can be used alone, or two or more polyols used in this embodiment can be used in combination, preferably diols, more preferably ester diols, alkylene diols, and carbonate diols. Alcohols, especially ester diols and carbonate diols.

Examples of ester diols include alkanediols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol. ; ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol, alkanediol and other glycols, and one or more kinds selected from phthalic acid, isophthalic acid, terephthalic acid, Naphthalene dicarboxylic acid, 4,4-diphenyldicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, chlorobridge acid, horse Toric acid, fumaric acid, itaconic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, hexahydrophthalic acid, hexahydroisophthalic acid, six Polycondensation products of one or more kinds of dicarboxylic acids such as hydroterephthalic acid and methylhexahydrophthalic acid, and their anhydrides. Specifically, polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyhexamethylene isophthalate diol, polyhexamethylene adipate diol, polyhexamethylene adipate Neopentyl adipate diol, polyethylene dipropylene adipate diol, polyethylene butylene adipate diol, polybutylene dihexyl adipate diol, polypolyethylene adipate diol Ethylene glycol, poly(p-methylene ether) adipate diol, poly(3-methylpentylene adipate) diol, polyethylene azelate diol, poly Ethylene sebacate diol, polybutylene azelate diol, polybutylene sebacate diol, polyneopentyl terephthalate diol, etc.

Examples of alkylene diols include alkane diols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol. Alcohols; alkylene glycols such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol; polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; polytetramethylene glycols, etc. Oxyalkylene glycol, etc.

Examples of carbonate diols include 1,4-tetramethylene carbonate diol, 1,5-pentamethylene carbonate diol, 1,6-hexamethylene carbonate diol, 1,2-Propylene Carbonate Diol, 1,3-Propylene Carbonate Diol, 2,2-Dimethyl Propylene Carbonate Diol, 1,7-Heptamethylene Carbonate Diol alcohol, 1,8-octamethylene carbonate diol and 1,4-cyclohexane carbonate diol, etc.

Examples of the polyvalent isocyanate used as a raw material for the urethane prepolymer (UP) include aromatic polyisocyanate, aliphatic polyisocyanate, and alicyclic polyisocyanate. These polyvalent isocyanates can be used alone or in combination of two or more. In addition, these polyisocyanates can also be trimethylolpropane addition-type modifiers, biuret-type modifiers formed by reacting with water, and isocyanurates containing isocyanurate rings. type modifier.

Among them, the polyvalent isocyanate used in this embodiment is preferably a diisocyanate, more preferably made of 4,4'-diphenylmethane diisocyanate (MDI), 2,4-toluene diisocyanate (2, 4-TDI), 2,6-toluene diisocyanate (2,6-TDI), hexamethylene diisocyanate (HMDI) and alicyclic diisocyanate at least one.

Examples of the alicyclic diisocyanate include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate and methyl-2,6-cyclohexane diisocyanate, etc., preferably Isophorone diisocyanate (IPDI).

In this embodiment, the urethane prepolymer (UP) serving as the main chain of the urethane acrylate resin (U1) is preferably a reaction product of a diol and a diisocyanate. Linear urethane prepolymer with ethylenically unsaturated groups at the end. Examples of methods for introducing ethylenically unsaturated groups at both ends of the linear urethane prepolymer include linear urethane prepolymers obtained by reacting diols with diisocyanate compounds. A method of reacting the NCO group at the end of the compound with a hydroxyalkyl (meth)acrylate.

Examples of hydroxyalkyl (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, (meth)acrylate ) 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate, etc.

As a vinyl compound used as a side chain of the urethane acrylate resin (U1), at least (meth)acrylate is contained. The (meth)acrylate is preferably at least one selected from alkyl (meth)acrylates and hydroxyalkyl (meth)acrylates, more preferably alkyl (meth)acrylates and (meth)acrylates are used in combination. ) hydroxyalkyl acrylate.

When an alkyl (meth)acrylate and a hydroxyalkyl (meth)acrylate are used together, the ratio of the hydroxyalkyl (meth)acrylate to 100 parts by mass of the alkyl (meth)acrylate is preferably 0.1 to 100 Parts by mass are more preferably 0.5 to 30 parts by mass, particularly preferably 1.0 to 20 parts by mass, and still more preferably 1.5 to 10 parts by mass.

The carbon number of the alkyl group which the alkyl (meth)acrylate has becomes like this. Preferably it is 1-24, More preferably, it is 1-12, Especially preferably, it is 1-8, Most preferably, it is 1-3.

In addition, examples of the hydroxyalkyl (meth)acrylate include the same as the hydroxyalkyl (meth)acrylate used to introduce ethylenically unsaturated groups at both ends of the linear urethane prepolymer described above. the same.

Vinyl compounds other than (meth)acrylates include, for example, aromatic hydrocarbon-based vinyl compounds such as styrene, a-methylstyrene, and vinyl toluene; methyl vinyl ether and ethyl vinyl Vinyl ethers such as ethers; vinyl acetate, vinyl propionate, (meth)acrylonitrile, N-vinylpyrrolidone, (meth)acrylic acid, maleic acid, fumaric acid, itaconic acid and Polar group-containing monomers such as methyl (acrylamide), etc. These lines can be used alone or in combination of two or more.

The content of the (meth)acrylate in the vinyl compound is preferably from 40 to 100% by mass, more preferably from 65 to 100% by mass, with respect to the total amount (100% by mass) of the vinyl compound, and most preferably 80 to 100% by mass, especially preferably 90 to 100% by mass.

The total content of alkyl (meth)acrylate and hydroxyalkyl (meth)acrylate in the vinyl compound is preferably from 40 to 100% by mass based on the total amount (100% by mass) of the vinyl compound, more preferably Preferably, it is 65-100 mass %, More preferably, it is 80-100 mass %, More preferably, it is 90-100 mass %.

The acrylic urethane resin (U1) used in this embodiment is obtained by mixing the urethane prepolymer (UP) and a vinyl compound containing (meth)acrylate, and polymerizing the two . The polymerization is preferably carried out by further adding a free radical initiator.

In the urethane acrylate resin (U1) used in this embodiment, the content of the structural unit (u11) derived from the urethane prepolymer (UP) and the structural unit (u12) derived from the vinyl compound The ratio [(u11)/(u12)] is based on mass ratio, preferably 10/90～80/20, more preferably 20/80～70/30, especially 30/70～60/40, especially More preferably, it is 35/65-55/45.

(Olefin-Based Resin) A suitable olefin-based resin of the resin contained in the resin composition (y) is a polymer having at least a constituent unit derived from an olefin monomer. As the above-mentioned olefin monomer, an a-olefin having 2 to 8 carbon atoms is preferable, and specific examples thereof include ethylene, propylene, butene, isobutene, and 1-hexene. Among these, ethylene and propylene are preferred.

Specific olefin-based resins include, for example, ultra-low-density polyethylene (VLDPE, density: 880 kg/m ³ or more and less than 910 kg/m ³ ), low-density polyethylene (LDPE, density: 910 kg/m ³ or more), and less than 915kg/m ³ ), medium-density polyethylene (MDPE, density: more than 915kg/m ³ and less than 942kg/m ³ ), high-density polyethylene (HDPE, density: more than 942kg/m ³ ) and linear polyethylene resin such as low-density polyethylene; polypropylene resin (PP); polybutene resin (PB); ethylene-propylene copolymer; olefin-based elastomer (TPO); ethylene) (PMP); ethylene-vinyl acetate copolymer (EVA); ethylene-vinyl alcohol copolymer (EVOH); ethylene-propylene-(5-ethylidene-2-norbornene) and other olefinic ternary components Copolymer etc.

In this embodiment, the olefin-based resin may be a modified olefin-based resin further modified by one or more types selected from acid modification, hydroxyl modification, and acrylic modification.

For example, acid-modified olefin-based resins obtained by subjecting olefin-based resins to acid modification include those obtained by graft-polymerizing unsaturated carboxylic acids or their anhydrides to the above-mentioned unmodified olefin-based resins. mass polymer. Examples of the unsaturated carboxylic acid or its anhydride include maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, tetrahydrophthalic acid, aconitic acid, and (meth)acrylic acid. , maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic anhydride and tetrahydrophthalic anhydride, etc. In addition, unsaturated carboxylic acids or their anhydrides may be used alone or in combination of two or more.

Examples of acrylic-modified olefin-based resins obtained by modifying acrylic acid to olefin-based resins include graft-polymerizing (meth)acrylic alkylenes as side chains to the above-mentioned unmodified olefin-based resins as the main chain. Modified polymer made from ester. The number of carbon atoms in the alkyl group of the above-mentioned alkyl (meth)acrylate is preferably 1-20, more preferably 1-16, and especially preferably 1-12. Examples of the above-mentioned alkyl (meth)acrylate include the same compounds that can be selected as the monomer (a1') described later.

Examples of hydroxyl-modified olefin-based resins obtained by modifying hydroxyl groups on olefin-based resins include modified polymers obtained by graft-polymerizing hydroxyl-containing compounds to the above-mentioned unmodified olefin-based resins as the main chain. thing. Examples of the hydroxyl group-containing compound include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, (meth)acrylic acid 2 Hydroxyalkyl (meth)acrylates such as -hydroxybutyrate, 3-hydroxybutyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate; unsaturated alcohols such as vinyl alcohol and allyl alcohol class etc.

(Resins other than urethane-acrylic resins and olefin-based resins) In this embodiment, the resin composition (y) may contain urethane Resins other than ester resins and olefin resins. Examples of such resins include vinyl resins such as polyvinyl chloride, polyvinylidene chloride, and polyvinyl alcohol; polyethylene terephthalate, polybutylene terephthalate, and polynaphthalate; Polyester resins such as ethylene glycol; polystyrene; acrylonitrile-butadiene-styrene copolymer; cellulose triacetate; polycarbonate; polyamine groups other than acrylic urethane resins Formic acid ester; polyamide; polyether ether ketone; polyether resin; polyphenylene sulfide; polyimide resins such as polyetherimide and polyimide; polyamide resin; acrylic resin; fluorine resin etc. The content ratio of the resin other than the urethane-acrylic resin and the olefin-based resin is preferably less than 30 parts by mass, more preferably less than 30 parts by mass, based on 100 parts by mass of the total amount of the resin contained in the resin composition (y). It is less than 20 parts by mass, more preferably less than 10 parts by mass, particularly preferably less than 5 parts by mass, and still more preferably less than 1 part by mass.

[Heat-expandable particles] The heat-expandable particles may be particles as long as they expand by heating, but it is preferable to use particles whose expansion start temperature (t) is adjusted to 120 to 250°C. The expansion start temperature (t) is appropriately selected according to the application. In addition, in this specification, the expansion start temperature (t) of a heat-expandable particle means the value measured according to the following method. (Measurement method of expansion start temperature (t) of heat-expandable particles) In an aluminum cup with a diameter of 6.0mm (inner diameter of 5.65mm) and a depth of 4.8mm, add 0.5mg of heat-expandable particles to be measured, and make a container on top of it. A sample with an aluminum cover (diameter 5.6mm, thickness 0.1mm). Using a dynamic viscoelasticity measuring device, measure the height of the sample under the condition that a force of 0.01N is applied from the upper part of the aluminum cover through the pressure head. Then, in the state where the force of 0.01N is applied by the pressure head, heat it at a heating rate of 10°C/min from 20°C to 300°C, measure the displacement in the vertical direction of the pressure head, and move it in the positive direction The displacement start temperature of is taken as the expansion start temperature (t).

The heat-expandable particles are preferably microencapsulated foaming agents composed of an outer shell made of a thermoplastic resin and a component enclosed in the outer shell and vaporized when heated to a specific temperature. Examples of the thermoplastic resin constituting the shell of the microencapsulated blowing agent include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, poly Vinylidene Chloride and Polyethylene, etc.

Examples of the internal components contained in the shell include propane, butane, pentane, hexane, heptane, octane, nonane, decane, isobutane, isopentane, isohexane, isohexane, Heptane, isooctane, isononane, isodecane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, neopentane, dodecane, isododecane , Cyclotridecane, Hexylcyclohexane, Tridecane, Tetradecane, Pentadecane, Hexadecane, Heptadecane, Octadecane, Nonadecane, Isotridecane, 4-Methyldodecane Alkane, Isotetradecane, Isopentadecane, Isohexadecane, 2,2,4,4,6,8,8-Heptamethylnonane, Isoheptadecane, Isoctadecane, Isnonadecane Alkane, 2,6,10,14-tetramethylpentadecane, cyclotridecane, heptylcyclohexane, n-octylcyclohexane, cyclopentadecane, nonylcyclohexane, decylcyclohexane alkane, pentadecylcyclohexane, hexadecylcyclohexane, heptadecylcyclohexane and octadecylcyclohexane, etc. These internal components can be used alone or in combination of two or more. The expansion start temperature (t) of heat-expandable particles can be adjusted by properly selecting the type of internal components.

In this embodiment, the average particle diameter of the heat-expandable particles before expansion at 23° C. is preferably 3-100 μm, more preferably 4-70 μm, particularly preferably 6-60 μm, and still more preferably 10-50 μm. Furthermore, the average particle diameter before expansion of the so-called heat-expandable particles is the volume median particle diameter (D ₅₀ ), which means that a laser diffraction particle size distribution measuring device (for example, manufactured by Malvern Company, product name "Mastersizer 3000") ”) measurement, in the particle distribution of the heat-expandable particles before expansion, the cumulative volume frequency calculated from the smaller particle diameter of the heat-expandable particles before expansion corresponds to 50% of the particle diameter.

In this embodiment, the 90% particle diameter (D ₉₀ ) before expansion at 23°C of the heat-expandable particles is preferably 10-150 μm, more preferably 20-100 μm, especially preferably 25-90 μm, and even more preferably 30-80μm. Furthermore, the 90% particle size (D ₉₀ ) before expansion of the so-called heat-expandable particles means that it is measured using a laser diffraction particle size distribution analyzer (for example, manufactured by Malvern Company, product name "Mastersizer 3000"). In the particle distribution of the heat-expandable particles before expansion, the cumulative volume frequency calculated from the smaller particle diameter of the heat-expandable particles corresponds to the particle diameter of 90%.

The maximum volume expansion ratio when heated to a temperature above the expansion start temperature (t) of the thermally expandable particles used in this embodiment is preferably 1.5 to 100 times, more preferably 2 to 80 times, and most preferably 2.5 to 60 times , especially more preferably 3 to 40 times.

The content of the heat-expandable particles is preferably from 1 to 40% by mass, more preferably from 5 to 35% by mass, and most preferably from 10 to 30% by mass relative to the total amount (100% by mass) of active ingredients in the resin composition (y). , especially preferably 15 to 25% by mass.

[Additives for substrates] The resin composition (y) used in this embodiment may contain additives for substrates contained in the substrates of general adhesive sheets within the range that does not impair the effects of the present invention. Such additives for substrates include, for example, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, slip agents, antiblocking agents, and coloring agents. Furthermore, these substrate additives may be used alone or in combination of two or more. When these base material additives are contained, the content of each base material additive is preferably from 0.0001 to 20 parts by mass, more preferably from 0.001 to 10 parts by mass, based on 100 parts by mass of the aforementioned resin in the resin composition (y). share.

(Solvent-free resin composition (y1)) As the resin composition (y) used in this embodiment, an oligomer having an ethylenically unsaturated group blended with a mass average molecular weight (Mw) of 50,000 or less, A solvent-free resin composition (y1) that is made of an energy ray polymerizable monomer and the above-mentioned expandable particles without mixing a solvent. In the solvent-free resin composition (y1), no solvent is mixed, but the energy ray polymerizable monomer contributes to the improvement of the plasticity of the aforementioned oligomer. A thermally expandable substrate can be formed by irradiating energy rays to a coating film formed of the solvent-free resin composition (y1).

The type, shape, and blending amount (content) of the expandable particles blended in the solvent-free resin composition (y1) are as above.

The mass average molecular weight (Mw) of the aforementioned oligomer contained in the solvent-free resin composition (y1) is 50000 or less, preferably 1000-50000, more preferably 2000-40000, especially preferably 3000-35000, especially More preferably, it is 4,000 to 30,000.

Furthermore, as the aforementioned oligomer, among the resins contained in the aforementioned resin composition (y), any one having an ethylenically unsaturated group having a mass average molecular weight (Mw) of 50,000 or less may be used, but the aforementioned oligomer is preferably Urethane prepolymer (UP). Furthermore, as the oligomer, a modified olefin resin having an ethylenically unsaturated group, etc. can also be used.

The total content of the aforementioned oligomer and the aforementioned energy ray polymerizable monomer in the solvent-free resin composition (y1) is preferably 50% with respect to the total amount (100% by mass) of the solvent-free resin composition (y1). % to 99% by mass, more preferably 60 to 95% by mass, especially preferably 65 to 90% by mass, even more preferably 70 to 85% by mass.

Examples of energy ray polymerizable monomers include isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and dicyclopentanyl (meth)acrylate. Alicyclic polymerizable compounds such as alkenyloxyester, cyclohexyl (meth)acrylate, adamantyl (meth)acrylate and tricyclodecane acrylate; phenylhydroxypropyl acrylate, benzyl acrylate and phenol ring Aromatic polymeric compounds such as oxyethane-modified acrylates; heterocycles such as tetrahydrofurfuryl (meth)acrylate, morpholine acrylate, N-vinylpyrrolidone and N-vinylcaprolactam Formula polymeric compounds, etc. These energy ray polymerizable monomers can be used alone or in combination of two or more.

The content ratio of the aforementioned oligomer to the aforementioned energy ray polymerizable monomer in the solvent-free resin composition (y1) [oligomer/energy ray polymerizable monomer] is based on mass ratio, preferably 20/80 ~90/10, more preferably 30/70~85/15, especially preferably 35/65~80/20.

In this embodiment, the solvent-free resin composition (y1) is preferably formed by further blending a photopolymerization initiator. Since it contains a photopolymerization initiator, the hardening reaction can be fully carried out even by the irradiation of relatively low-energy energy rays.

Examples of photopolymerization initiators include 1-hydroxy-cyclohexyl-phenyl-ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzyl Phenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, bibenzyl, diacetyl and 8-chloroanthraquinone, etc. These photopolymerization initiators can be used alone or in combination of two or more.

The blending amount of the photopolymerization initiator is preferably 0.01 to 5 parts by mass, more preferably 0.01 to 4 parts by mass, and most preferably It is 0.02 to 3 parts by mass.

[Adhesive layer (X1)] The adhesive layer (X1) of the adhesive sheet according to this embodiment may contain an adhesive resin, and may contain a crosslinking agent, a tackifier, or a polymerizable compound as necessary. Additives for adhesives such as polymerization initiators.

In the adhesive sheet of this embodiment, the adhesive force of the adhesive surface of the adhesive layer (X1) at 23° C. before expansion of the heat-expandable particles is preferably 0.1 to 10.0 N/25 mm, more preferably 0.2 to 8.0 N/25 mm. 25mm, especially preferably 0.4-6.0N/25mm, even more preferably 0.5-4.0N/25mm. If the adhesive force is 0.1N/25mm or more, it is possible to prevent the position of the adherend from shifting and fix it sufficiently. In addition, it is also possible to sufficiently fix the semiconductor wafer to such an extent that the displacement of the position of the semiconductor chip in the above-mentioned packaging step can be prevented. On the other hand, if the adhesive force is 10.0N/25mm or less, when the adherend is peeled off and separated, it can be easily separated. Furthermore, the above-mentioned adhesive force refers to the value measured by the method described in the examples.

The adhesive layer (X1) can be formed from an adhesive composition containing an adhesive resin. Hereinafter, each component contained in the adhesive composition which is a forming material of the adhesive layer (X1) is demonstrated.

[Adhesive Resin] The adhesive resin used in this embodiment is preferably a polymer having adhesiveness alone and a mass average molecular weight (Mw) of 10,000 or more. From the viewpoint of improving the adhesive force, the mass average molecular weight (Mw) of the adhesive resin used in this embodiment is more preferably 10,000 to 2 million, particularly preferably 20,000 to 1.5 million, and even more preferably 30,000 to 1.5 million. 1000000.

Examples of adhesive resins include rubber-based resins such as acrylic resins, urethane-based resins, and polyisobutylene-based resins, polyester-based resins, olefin-based resins, silicone-based resins, and polyvinyl ethers. Department of resin, etc. These adhesive resins can be used alone or in combination of two or more. Also, when these adhesive resins are copolymers having two or more constituent units, the form of the copolymer is not particularly limited, and it may be a block copolymer, a random copolymer, or a graft copolymer. either.

The adhesive resin used in this embodiment may be an energy ray-curable adhesive resin in which a polymerizable functional group is introduced into a side chain of the aforementioned adhesive resin. Examples of the polymerizable functional group include (meth)acryl and vinyl groups. Also, examples of energy rays include ultraviolet rays and electron rays, among which ultraviolet rays are preferred.

The content of the adhesive resin is preferably 30-99.99% by mass, more preferably 40-99.95% by mass, particularly preferably 50-99.90% by mass, especially More preferably, it is 55 to 99.80 mass %, and most preferably, it is 60 to 99.50 mass %. In addition, in the following descriptions of this specification, "the content of each component relative to the total amount of the active ingredients of the adhesive composition" means the same as "the content of each component in the adhesive layer formed from the adhesive composition." Content" is synonymous.

In this embodiment, from the point of view of exhibiting excellent adhesive force and expanding the heat-expandable particles in the heat-expandable substrate by heat treatment, unevenness is easily formed on the adhesion surface of the adhesive layer (X1). The permanent resin preferably contains an acrylic resin. The content of the acrylic resin in the adhesive resin is preferably from 30 to 100% by mass, more preferably from 50 to 100% by mass, based on the total amount (100% by mass) of the adhesive resin contained in the adhesive composition. More preferably, it is 70 to 100% by mass, and even more preferably, it is 85 to 100% by mass.

(Acrylic resin) In this embodiment, as an acrylic resin that can be used as an adhesive resin, for example, one containing a structural unit derived from an alkyl (meth)acrylate having a linear or branched alkyl group is mentioned. A polymer, a polymer including a constituent unit derived from a (meth)acrylate having a ring structure, and the like.

The mass average molecular weight (Mw) of the acrylic resin is preferably from 100,000 to 1.5 million, more preferably from 200,000 to 1.3 million, especially preferably from 350,000 to 1.2 million, and even more preferably from 500,000 to 1.1 million.

As an acrylic resin, it is more preferable to have a structural unit (a1) derived from an alkyl (meth)acrylate (a1') (hereinafter also referred to as "monomer (a1')") and a monomer derived from a functional group. (a2') (Hereinafter, also referred to as "monomer (a2')") Acrylic copolymer (A1) of the structural unit (a2).

The number of carbon atoms in the alkyl group of the monomer (a1') is preferably from 1 to 24, more preferably from 1 to 12, especially preferably from 2 to 10, and still more preferably from 4, from the viewpoint of improving the adhesive properties. ~8. Furthermore, the alkyl group contained in the monomer (a1') may be a straight-chain alkyl group or a branched-chain alkyl group.

Examples of the monomer (a1') include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylic acid 2 -Ethylhexyl, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, etc. These monomers (a1') may be used alone or in combination of two or more. As the monomer (a1'), butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate are preferred.

The content of the structural unit (a1) is preferably from 50 to 99.9% by mass, more preferably from 60 to 99.0% by mass, and most preferably from 70 to 97.0% by mass relative to all the structural units (100% by mass) of the acrylic copolymer (A1). % by mass, especially preferably 80 to 95.0% by mass.

Examples of the functional group contained in the monomer (a2') include a hydroxyl group, a carboxyl group, an amino group, and an epoxy group. That is, as the monomer (a2'), for example, a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, etc. can be mentioned. These monomers (a2') may be used alone or in combination of two or more. Among them, the monomer (a2') is preferably a hydroxyl group-containing monomer or a carboxyl group-containing monomer.

As a hydroxyl group-containing monomer, the thing similar to the said hydroxyl group-containing compound is mentioned, for example.

Examples of carboxyl group-containing monomers include ethylenically unsaturated monocarboxylic acids such as (meth)acrylic acid and crotonic acid; ethylenically unsaturated monocarboxylic acids such as fumaric acid, itaconic acid, maleic acid, and citraconic acid; Dicarboxylic acid and its anhydride, 2-(acryloxy)ethyl succinate, 2-carboxyethyl (meth)acrylate, etc.

The content of the structural unit (a2) is preferably from 0.1 to 40% by mass, more preferably from 0.5 to 35% by mass, particularly preferably from 1.0 to 30% by mass, based on all the structural units (100% by mass) of the acrylic copolymer (A1). % by mass, especially preferably 3.0 to 25% by mass.

The acrylic copolymer (A1) may further have a structural unit (a3) derived from a monomer (a3') other than the monomers (a1') and (a2'). In addition, in the acrylic copolymer (A1), the content of the structural units (a1) and (a2) is preferably 70 to 100 mass with respect to all the structural units (100 mass %) of the acrylic copolymer (A1). %, more preferably 80 to 100% by mass, especially preferably 90 to 100% by mass, even more preferably 95 to 100% by mass.

Examples of the monomer (a3') include olefins such as ethylene, propylene, and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; and olefins such as butadiene, isoprene, and chloroprene. Diene monomers; cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, bicyclo(meth)acrylate (Meth)acrylic acid esters having a ring structure, such as pentenyl ester, dicyclopentenyloxyethyl (meth)acrylate, and imide (meth)acrylate; styrene, a-methylstyrene , vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, (meth)acrylamide, (meth)acrylonitrile, (meth)acrylmorpholine and N-vinylpyrrolidone, etc.

In addition, the acrylic copolymer (A1) may be an energy-ray-curable acrylic copolymer having a polymerizable functional group introduced into a side chain. The polymerizable functional group and the energy line are as described above. Furthermore, the polymerizable functional group can be obtained by making the acrylic copolymer having the above-mentioned structural units (a1) and (a2) and the functional group possessed by the structural unit (a2) of the acrylic copolymer A bonded substituent and a compound of a polymerizable functional group are reacted and introduced. Examples of the compound include (meth)acryloxyethyl isocyanate, (meth)acryl isocyanate, and glycidyl (meth)acrylate.

(Crosslinking agent) In this embodiment, when the adhesive composition contains a functional group-containing adhesive resin such as the above-mentioned acrylic copolymer (A1), it is preferable to further contain a crosslinking agent. The cross-linking agent reacts with the adhesive resin having a functional group, and uses the functional group as a cross-linking starting point to cross-link the adhesive resin with each other.

As a crosslinking agent, an isocyanate type crosslinking agent, an epoxy type crosslinking agent, an aziridine type crosslinking agent, a metal chelate type crosslinking agent etc. are mentioned, for example. These cross-linking agents can be used alone or in combination of two or more. Among these cross-linking agents, isocyanate-based cross-linking agents are preferred from the standpoint of improving cohesion to increase adhesive force and ease of acquisition.

The content of the crosslinking agent can be appropriately adjusted according to the number of functional groups in the adhesive resin, for example, it is preferably 0.01-10 parts by mass, more preferably 0.03- 7 parts by mass, preferably 0.05 to 5 parts by mass.

(Tackifier) In this embodiment, the adhesive composition may further contain a tackifier from the viewpoint of further improving the adhesive force. In this specification, the so-called "tackifier" is a component that assists in improving the adhesive force of the above-mentioned adhesive resin. differencer. The mass average molecular weight (Mw) of the tackifier is preferably from 400 to less than 10,000, more preferably from 500 to 8,000, and especially preferably from 800 to 5,000.

Examples of tackifiers include rosin-based resins, terpene-based resins, styrene-based resins, pentene, isoprene, piperine, and 1,3-pentanediene produced by copolymerization due to thermal decomposition of naphtha. C5-based petroleum resins obtained from C5 fractions such as alkene, C9-based petroleum resins obtained by copolymerizing C9 fractions such as indene and vinyltoluene produced by thermal decomposition of naphtha, and hydrogenated resins obtained by hydrogenating these.

The softening point of the tackifier is preferably 60-170°C, more preferably 65-160°C, and most preferably 70-150°C. Furthermore, in this specification, the "softening point" of a tackifier refers to a value measured in accordance with JIS K 2531. Tackifiers can be used alone, or two or more types with different softening points and structures can be used in combination. Furthermore, when using two or more plural tackifiers, the weighted average of the softening points of the plural tackifiers preferably falls within the aforementioned range.

The content of the tackifier is preferably from 0.01 to 65% by mass, more preferably from 0.05 to 55% by mass, especially preferably from 0.1 to 50% by mass, with respect to the total amount (100% by mass) of active ingredients of the adhesive composition, especially More preferably, it is 0.5-45 mass %, Most preferably, it is 1.0-40 mass %.

(Photopolymerization initiator) In this embodiment, when the adhesive composition contains an energy ray-curable adhesive resin as the adhesive resin, it is preferable to further contain a photopolymerization initiator. Since it becomes an adhesive composition containing an energy ray-curable adhesive resin and a photopolymerization initiator, the adhesive layer (X1) formed from the adhesive composition is irradiated with relatively low-energy energy rays, It is also possible to fully carry out the hardening reaction and adjust the adhesive force to a desired range. Furthermore, examples of the photopolymerization initiator used in this embodiment include the same ones as those blended in the above-mentioned solvent-free resin composition (y1).

The content of the photopolymerization initiator is preferably from 0.01 to 10 parts by mass, more preferably from 0.03 to 5 parts by mass, and most preferably from 0.05 to 2 parts by mass, based on 100 parts by mass of the energy ray-curable adhesive resin.

(Additives for Adhesives) In this embodiment, the adhesive composition of the material forming the adhesive layer (X1) may contain, in addition to the above-mentioned additives, general adhesives within the range that does not impair the effect of the present invention. Adhesive additives used in adhesives. Examples of such adhesive additives include antioxidants, softeners (plasticizers), antirust agents, pigments, dyes, retarders, reaction accelerators (catalysts), and ultraviolet absorbers. Furthermore, these adhesive additives may be used alone or in combination of two or more.

When these adhesive additives are contained, the content of each adhesive additive is preferably 0.0001 to 20 parts by mass, more preferably 0.001 to 10 parts by mass, based on 100 parts by mass of the adhesive resin.

Furthermore, the adhesive layer (X1) included in the adhesive sheet of the present embodiment suppresses residues from heat-expandable particles from adhering to the surface of the processed inspection object or after thermal peeling due to residual glue on the surface of the processed inspection object. From the viewpoint of contamination of the surface of the object to be inspected during processing, a non-expandable adhesive layer is preferred. The content of the heat-expandable particles in the adhesive layer (X1) is preferable relative to the total amount (100% by mass) of the active ingredients of the adhesive composition, or relative to the total mass (100% by mass) of the adhesive layer (X1) It is less than 1% by mass, more preferably less than 0.1% by mass, especially preferably less than 0.01% by mass, and still more preferably less than 0.001% by mass.

[Adhesive layer (X2)] When the adhesive sheet of this embodiment is a double-sided adhesive sheet, as long as the adhesive layer (X2) of the double-sided adhesive sheet contains an adhesive resin, it may also contain an adhesive resin if necessary. Adhesive additives such as linking agent, tackifier, polymerizable compound, polymerization initiator, etc. The preferred aspect of the composition and form of the adhesive layer (X2) is the same as that of the adhesive layer (X1). However, the composition of the adhesive layer (X1) and the adhesive layer (X2) may be the same or different. Also, the form of the adhesive layer (X1) and the adhesive layer (X2) may be the same or different. Furthermore, the adhesive layer (X2) of the adhesive sheet according to this embodiment is preferably the same as the adhesive layer (X1) from the viewpoint of maintaining the adhesive force with the hard support without reducing the heat. The same applies to the non-expandable adhesive layer. The content of the heat-expandable particles in the adhesive layer (X2) is preferable relative to the total amount (100% by mass) of the active ingredients of the adhesive composition, or relative to the total mass (100% by mass) of the adhesive layer (X2) It is less than 1% by mass, more preferably less than 0.1% by mass, especially preferably less than 0.01% by mass, and still more preferably less than 0.001% by mass.

Furthermore, the storage shear modulus G'(23) at 23°C of the adhesive layer (X2) is preferably from 1.0×10 ⁴ to 1.0×10 ⁸ Pa, more preferably 3.0×10 ⁴ to 5.0×10 ⁷ Pa, most preferably 5.0×10 ⁴ to 1.0×10 ⁷ Pa.

[Release material] The double-sided adhesive sheet of this embodiment is the adhesive sheet 1b shown in Figure 1 (b) and the adhesive sheet 2b shown in Figure 2 (b), and can also be placed on the adhesive layer (X1) and/or The adhesive layer (X2) further has a release material on the adhesive surface. Furthermore, the adhesive sheet 2b shown in Figure 2(b) is arranged on the adhesive layer (X1) and the adhesive layer (X1) in the double-sided adhesive sheet with the adhesive layer (X1) and the adhesive The two release materials on the respective adhesive surfaces of the layers (X2) are preferably adjusted so that the difference in release force is different. As the release material, a release sheet with double-side release treatment, a release sheet with one-side release treatment, etc., or one coated with a release agent on the base material for the release material can be used.

As the substrate for the release material, for example, papers such as high-quality paper, cellophane, and kraft paper; polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin; Polyester resin films such as ester resins, plastic films such as olefin resin films such as polypropylene resins and polyethylene resins, etc.

Examples of release agents include silicone-based resins, olefin-based resins, rubber-based elastomers such as isoprene-based resins, and butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, and fluorine-based resins. Department of resin, etc.

The thickness of the release material is not particularly limited, but is preferably 10-200 μm, more preferably 25-170 μm, and most preferably 35-80 μm. Example

The present invention will be described more specifically by the following examples, but the present invention is not limited by the following examples. In addition, the physical property value in the following manufacture example and an Example is the value measured by the following method.

<Mass average molecular weight (Mw)> Using a gel permeation chromatography device (manufactured by Tosoh Co., Ltd., product name "HLC-8020"), it was measured under the following conditions, and was measured using standard polystyrene conversion. (Measurement conditions) ・Column: Connected in sequence with "TSK guard column HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL", "TSK gel G1000HXL" (manufactured by Tosoh Co., Ltd.) ・Column temperature: 40℃ ・Developing solvent: tetrahydrofuran ・Flow rate: 1.0mL/min

<Measurement of the thickness of each layer> The measurement was carried out using a constant pressure thickness tester manufactured by TECLOCK Co., Ltd. (model: "PG-02J", based on standard specifications: JIS K6783, Z1702, Z1709).

<Average particle diameter (D ₅₀ ), 90% particle diameter (D ₉₀ ) of heat-expandable particles> Measured at 23°C using a laser diffraction particle size distribution analyzer (for example, manufactured by Malvern, product name "Mastersizer 3000") Particle distribution of heat-expandable particles before expansion in the middle. Then, the cumulative volume frequency calculated from the smaller particle size of the particle distribution is equivalent to 50% and 90% of the particle size, respectively as the "average particle size of heat-expandable fine particles (D ₅₀ )" and "heat-expandable particle size". 90% particle size (D ₉₀ )”.

<Storage modulus E' of thermally expandable base material> When the measurement object is a non-adhesive thermally expandable base material, make the thermally expandable base material a size of 5 mm in length, 30 mm in width, and 200 μm in thickness, and remove the peeling material as For test samples. Using a dynamic viscoelasticity measuring device (manufactured by TA Instruments Co., Ltd., product name "DMAQ800"), under the conditions of test start temperature 0°C, test end temperature 300°C, heating rate 3°C/min, vibration frequency 1 Hz, and amplitude 20 μm, measure The storage modulus E' of the test sample at a specific temperature.

<Storage shear modulus G' of adhesive layer (X1) and adhesive layer (X2)> Cut the adhesive layer (X1) and adhesive layer (X2) into a circle with a diameter of 8mm, remove the release material, Lamination was carried out, and the one with a thickness of 3 mm was used as a test sample. Using a viscoelasticity measurement device (manufactured by Anton Paar, device name "MCR300"), under the conditions of test start temperature 0°C, test end temperature 300°C, temperature rise rate 3°C/min, vibration frequency 1 Hz, by torsional shear Method to measure the storage shear modulus G' of the test sample at a specific temperature.

<Probe Viscosity Value> Cut the heat-expandable substrate or expandable adhesive layer to be measured into a square of 10 mm on each side, and then let it stand at 23°C and 50%RH (relative humidity) for 24 hours. The light-peeling film was removed as the test sample. In an environment of 23°C and 50%RH (relative humidity), using a TACKING tester (manufactured by Nippon Special Sekki Co., Ltd., product name "NTS-4800"), according to JIS Z0237: 1991, the light peeling film has been removed and measured. The probe stickiness value of the exposed surface of the aforementioned test sample. Specifically, after making a stainless steel probe with a diameter of 5 mm contact the surface of the test sample with a contact load of 0.98 N/cm ² for 1 second, measure the time when the probe is separated from the surface of the test sample at a speed of 10 mm/sec. the strength needed. Then, the measured value was regarded as the probe viscosity value of the test sample.

Details of the adhesive resin, additives, heat-expandable particles, and release material used in the following production examples are as follows. ＜Adhesive resin＞ ・Acrylic copolymer (i): a solution containing an acrylic copolymer with a mass average molecular weight (Mw) of 600,000. -Constituent units derived from raw material monomers composed of hydroxyethyl ester (HEA)=80.0/20.0 (mass ratio). Dilution solvent: ethyl acetate, solid content concentration: 40% by mass.・Acrylic copolymer (ii): a solution containing an acrylic copolymer with a mass average molecular weight (Mw) of 600,000, which has a composition consisting of n-butyl acrylate (BA)/methyl methacrylate (MMA)/acrylic acid 2-Hydroxyethyl ester (HEA)/acrylic acid=86.0/8.0/5.0/1.0 (mass ratio) is a constituent unit derived from the raw material monomer. Diluting solvent: ethyl acetate, solid content concentration: 40% by mass <additive> ・Isocyanate crosslinking agent (i): manufactured by Tosoh Corporation, product name "Coronate L", solid content concentration: 75% by mass.・Photopolymerization initiator (i): BASF Corporation make, product name "Irgacure 184", 1-hydroxy-cyclohexyl-phenyl-ketone. <Heat-expandable particles> ・Heat-expandable particles (i): manufactured by KUREHA Co., Ltd., product name "S2640", expansion start temperature (t) = 208°C, average particle size (D ₅₀ ) = 24 μm, 90% particle size ( D ₉₀ ) = 49 μm. <Release material> ・Heavy release film: LINTEC Co., Ltd., product name "SP-PET382150", a polysiloxane-based release agent on one side of a polyethylene terephthalate (PET) film The thickness of the formed release agent layer: 38 μm.・Light release film: manufactured by LINTEC Co., Ltd., product name "SP-PET381031", with a release agent layer formed of a silicone release agent on one side of the PET film, thickness: 38 μm.

Production Example 1 (Formation of Adhesive Layer (X1)) 5.0 parts by mass of the above-mentioned isocyanate-based crosslinking agent (i) was blended into 100 parts by mass of the solid content of the above-mentioned acrylic copolymer (i) as an adhesive resin ( solid content ratio) was diluted with toluene and stirred uniformly to prepare a composition (x-1) having a solid content concentration (active component concentration) of 25% by mass. Then, on the surface of the release agent layer of the above-mentioned heavy release film, the prepared composition (x-1) was coated to form a coating film, and the coating film was dried at 100° C. for 60 seconds to form an adhesive layer with a thickness of 10 μm ( X1). Furthermore, the storage shear modulus G'(23) of the adhesive layer (X1) at 23°C was 2.5×10 ⁵ Pa.

Production Example 2 (Formation of Adhesive Layer (X2)) 0.8 parts by mass ( solid content ratio) was diluted with toluene and stirred uniformly to prepare a composition (x-2) having a solid content concentration (active component concentration) of 25% by mass. Then, on the surface of the release agent layer of the above-mentioned light release film, the prepared composition (x-2) was coated to form a coating film, and the coating film was dried at 100° C. for 60 seconds to form an adhesive layer with a thickness of 10 μm ( X2). Furthermore, the storage shear modulus G'(23) of the adhesive layer (X2) at 23°C was 9.0×10 ⁴ Pa.

Production Example 3 (Formation of Thermally Expandable Substrate (Y-1)) (1) Preparation of Composition (y-1) For terminal isocyanate obtained by reacting ester diol with isophorone diisocyanate (IPDI) The urethane prepolymer reacted 2-hydroxyethyl acrylate to obtain a bifunctional urethane acrylate oligomer with a mass average molecular weight (Mw) of 5,000. Then, 40 mass % (solid content ratio) of isobornyl acrylate (IBXA) as an energy ray polymerizable monomer was blended into 40 mass % (solid content ratio) of the urethane acrylate oligomer synthesized above. ) and 20% by mass (solid content ratio) of phenylhydroxypropyl acrylate (HPPA), relative to the total amount (100 parts by mass) of the urethane acrylate oligomer and the energy ray polymerizable monomer, further 2.0 parts by mass (solid content ratio) of 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Corporation, product name "Irgacure 184") as a photopolymerization initiator and 0.2 parts by mass (solid content ratio) of a phthalocyanine pigment as an additive were blended. Ingredient ratio) to modulate the energy ray hardening composition. Next, the above-mentioned heat-expandable particles (i) were mixed with this energy ray-curable composition to prepare a solvent-free composition (y-1) not containing a solvent. In addition, the content of the thermally expandable particles (i) is 20% by mass relative to the total amount (100% by mass) of the composition (y-1).

(2) Formation of thermally expandable substrate (Y-1) On the surface of the release agent layer of the above-mentioned light release film, the prepared composition (y-1) was applied to form a coating film. Then, using an ultraviolet irradiation device (manufactured by EYEGRAPHICS, product name "ECS-401GX") and a high-pressure mercury lamp (manufactured by EYEGRAPHICS, product name "H04-L41"), under the conditions of illuminance 160mW/cm ² and light intensity 500mJ/cm ² The coating film was hardened by irradiating ultraviolet rays downward to form a thermally expandable substrate (Y-1) with a thickness of 50 μm. In addition, the above-mentioned illuminance and light quantity at the time of ultraviolet irradiation are the values measured using the illuminance-light quantity meter (made by EIT company, a product name "UV Power Puck II").

Production Example 4 (Formation of thermally expandable substrate (Y-2)) (1) Synthesis of urethane prepolymer In a reaction vessel under a nitrogen atmosphere, for a carbonate type with a mass average molecular weight (Mw) of 1,000 100 parts by mass of diol (solid content ratio), isophorone diisocyanate (IPDI) is blended so that the equivalent ratio of the hydroxyl group of carbonate diol to the isocyanate group of isophorone diisocyanate becomes 1/1 , 160 parts by mass of toluene was further added, and the mixture was reacted at 80° C. for 6 hours or more while stirring in a nitrogen atmosphere until the isocyanate group concentration reached the theoretical amount. Next, a solution diluted with 1.44 parts by mass (solid content ratio) of 2-hydroxyethyl methacrylate (2-HEMA) in 30 parts by mass of toluene was added, and reacted at 80° C. for 6 hours until the isocyanate groups at both ends disappeared. , to obtain a urethane prepolymer with a mass average molecular weight (Mw) of 29,000.

(2) Synthesis of urethane acrylate resin In a reaction vessel under a nitrogen atmosphere, add 100 parts by mass (solid content ratio) of the urethane prepolymer obtained in the above (1), methyl methacrylate 117 parts by mass (solid content ratio) of ester (MMA), 5.1 parts by mass (solid content ratio) of 2-hydroxyethyl methacrylate (2-HEMA), 1.1 parts by mass (solid content ratio) of 1-thioglycerol, and 50 parts by mass of toluene parts by mass, while stirring, the temperature was raised to 105°C. Then, in the reaction vessel, a solution diluted with 2.2 parts by mass (solid content ratio) of a free radical initiator (manufactured by Finechem Co., Ltd. Japan, product name "ABN-E") with 210 parts by mass of toluene was maintained at 105°C, dropwise over 4 hours. After dropping, react at 105°C for 6 hours to obtain a solution of an acrylic urethane resin with a mass average molecular weight (Mw) of 105,000.

(3) Formation of thermally expandable substrate (Y-2) With respect to 100 parts by mass of the solid content of the solution of the urethane acrylate resin obtained in the above (2), 6.3 of the above-mentioned isocyanate-based crosslinking agent (i) was blended. Parts by mass (solid content ratio), 1.4 parts by mass (solid content ratio) of dioctyltin bis(2-ethylhexanoate) as a catalyst, and the above-mentioned thermally expandable particles (i), diluted with toluene, and stirred uniformly to prepare a composition (y-2) having a solid content concentration (active ingredient concentration) of 30% by mass. Furthermore, the content of the thermally expandable particles (i) was 20% by mass relative to the total amount (100% by mass) of the active ingredient in the obtained composition (y-2). Then, the prepared composition (y-2) was coated on the surface of the release agent layer of the light release film to form a coating film, and the coating film was dried at 100° C. for 120 seconds to form a thermally expandable film with a thickness of 50 μm. Substrate (Y-2).

For the heat-expandable substrates (Y-1)-(Y-2) formed in Production Examples 3-4, according to the above method, respectively measure 23°C, 100°C and 208°C of the expansion start temperature of the heat-expandable particles used. Storage modulus E' and probe viscosity value at °C. Table 1 shows these results.

[Table 1]

Example 1 The surface of the adhesive layer (X1) formed in Production Example 1 and the thermally expandable substrate (Y-1) formed in Production Example 3 were bonded together, and the side of the thermally expandable substrate (Y-1) was removed. On the surface of the exposed heat-expandable substrate (Y-1), the adhesive layer (X2) formed in Production Example 2 was pasted. In this way, an adhesive sheet (1) in which light release film/adhesive layer (X2)/heat-expandable substrate (Y-1)/adhesive layer (X1)/heavy release film were laminated in this order was produced.

Example 2 Except that the heat-expandable base material (Y-1) is replaced with the heat-expandable base material (Y-2) formed in Manufacturing Example 4, it is the same as in Example 1 to make sequentially laminated light release films/ Adhesive layer (X2)/heat-expandable base material (Y-2)/adhesive layer (X1)/adhesive sheet of heavy release film (2).

Moreover, the following measurement was performed about the produced adhesive sheets (1)-(2). Table 2 shows these results.

<Evaluation of positional displacement of semiconductor wafer during packaging process> Remove the light release film of the produced adhesive sheets (1) to (2), and stick on the adhesive surface of the exposed adhesive layer (X2) as SUS plate (thickness: 1mm, size: 200mmφ) of the rigid support. Then, remove the heavy peeling film of the adhesive sheets (1)-(2), and place a necessary Nine semiconductor wafers (wafer size: 6.4 mm×6.4 mm, wafer thickness: 200 μm (#2000)) were mounted at intervals of . After that, a resin film for encapsulation (encapsulation material) was laminated on the adhesive surface and the semiconductor wafer, and the adhesive layer was covered with the encapsulation material ( X1) bonding the surface and the semiconductor chip, and hardening the packaging material at the same time to produce a hardened package. In addition, the packaging conditions are as follows.・Preheating temperature: 100℃ for platform and diaphragm ・Evacuation: 60 seconds ・Dynamic pressurization mode: 30 seconds ・Static pressurization mode: 10 seconds 208℃ lower temperature) ・Encapsulation time: 60 minutes

After packaging, heat the adhesive sheets (1)-(2) for 3 minutes at 240°C above the expansion start temperature (208°C) of the heat-expandable particles, and peel off the hardened package from the adhesive sheets (1)-(2) Separation, the semiconductor wafer on the surface of the semiconductor wafer side of the separated cured package was observed visually and with a microscope to confirm whether there was positional displacement of the semiconductor wafer, and the following criteria were used for evaluation.・A: There is no semiconductor wafer with a positional deviation of more than 25 μm from that before packaging.・F: A semiconductor wafer with a positional deviation of more than 25 μm from that before packaging is seen.

<Evaluation of the flatness of the surface of the semiconductor wafer after the encapsulation process> Using the adhesive sheets (1) to (2), a cured package was produced in the same procedure as the above-mentioned "evaluation of positional displacement of the semiconductor wafer during the encapsulation process" body, separated from the adhesive sheet by peeling off. For the surface of each of the produced hardened packages on the side of the semiconductor wafer, use a contact surface roughness meter ("SV3000" manufactured by MITUTOYO Co., Ltd.) to measure the level difference, and evaluate according to the following criteria.・A: There is no place where a step difference of 2 μm or more occurs.・F: A place where a step difference of 2 μm or more occurs.

<Measurement of Adhesive Strength of Adhesive Sheets Before and After Heating> Remove the light peel film on the adhesive layer (X2) side of the prepared adhesive sheets (1)-(2), and place on the exposed adhesive layer (X2) A polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., product name "Cosmoshine A4100") with a thickness of 50 μm was laminated on the adhesive surface to form an adhesive sheet with a substrate. Then, remove the heavy release film on the adhesive layer (X1) side of the adhesive sheets (1)-(2), and attach the exposed adhesive surface of the adhesive layer (X1) to the stainless steel plate of the adherend (SUS304 No. 360 grinding), which will be left to stand for 24 hours under the environment of 23°C and 50%RH (relative humidity) as the test sample. Then, using the above-mentioned test sample, in an environment of 23°C and 50%RH (relative humidity), according to JIS Z0237:2000, by the 180° tearing method, at a tensile speed of 300mm/min, measure the temperature at 23°C Adhesion. Also, heat the above-mentioned test sample on a hot plate at 240°C, which is higher than the expansion start temperature (208°C) of the heat-expandable particles, for 3 minutes, and let it stand in a standard environment (23°C, 50%RH (relative humidity)). After 60 minutes, according to JIS Z0237: 2000, by the 180° tearing method, at a tensile speed of 300mm/min, the adhesive force after heating above the expansion start temperature was also measured. Furthermore, when it is difficult to measure the adhesion force because it cannot be attached to the stainless steel plate of the adherend, it is regarded as "unable to measure", and the adhesion force is regarded as 0 (N/25 mm).

<Evaluation of detachability for selection of singulated wafers> Remove the light release film on the adhesive layer (X2) side of the produced adhesive sheets (1) to (2), and place the exposed adhesive layer ( On the adhesive surface of X2), a vinyl chloride (PVC) film with a thickness of 60 μm was laminated to form an adhesive sheet with a substrate. Then, remove the heavy release film on the side of the adhesive layer (X1) that the adhesive sheets (1)-(2) have, and stick a silicon wafer (6 inches) on the adhesive surface of the exposed adhesive layer (X1). diameter, thickness 350 μm), the adhesive sheets (1) to (2) were mounted on a ring frame (made in SUS), set in a cutting device (manufactured by DISCO Co., Ltd., product name "DFD651"), and carried out under the following conditions Slicing to obtain a sliced wafer as a plurality of processing inspection objects.・Cutting knife: 27HEEE manufactured by DISCO Corporation ・Blade rotation speed: 50,000rpm ・Cutting speed: 10mm/sec ・Incision depth: from the substrate film to a depth of 20μm from the interface of the adhesive layer ・Cutting size: 2.5mm´ 2.5mnn Next, using an expansion jig (manufactured by NEC Machinery Co., Ltd., product name "CSP-100VX"), attach the adhesive sheet with a sliced wafer on the adhesive surface of the adhesive layer (X1), Pull off 5mm at a speed of 300mm/min. Then, as a heating part, prepare a heating means provided with a 2.5mm square and 1mm thick metal plate (made in SUS) and a thermally conductive rubber sheet (2.5mm square, 1mm thick) at the front end of the electric heater. The temperature of the part (most tip part) was heated with an electric heater so that the temperature may become 240 degreeC. Among a plurality of individualized wafers, the individualized wafers to be peeled are randomly selected, and the portion of the adhesive sheet attached to the selected individualized wafers is heated to reduce the adhesive force, Check whether the selected individualized wafers can be peeled off from the adhesive sheet with the suction nozzle. Then, an impact was forcibly applied to the individualized wafers attached to the non-heated portion of the adhesive sheet, and it was checked whether the individualized wafers fell off. The evaluation criteria were as follows.・A: The selected individualized wafers can be peeled off from the adhesive sheet with the suction nozzle, and there is no peeling off of the individualized wafers attached to the non-heated part of the adhesive sheet.・F: The selected individualized wafer cannot be peeled off from the adhesive sheet by the suction nozzle. Or, although peeling was possible, peeling of the individualized wafers attached to the non-heated portion of the adhesive sheet was observed.

(＊)：由於無法將試驗樣品貼附到被黏體(SUS板)，故無法測定黏著力。[Table 2]

(*): Since the test sample could not be attached to the adherend (SUS plate), the adhesive force could not be measured.

According to Table 2, if according to the manufacturing method using the adhesive sheets (1) and (2) of Examples 1 and 2, the positional deviation of the semiconductor chip during the packaging step can not be seen, and the position of the semiconductor chip side after the packaging step The surface is also flat. Also, the adhesive sheets (1) and (2) had good adhesive force before heating, but after heating above the expansion start temperature, the adhesive force decreased to such an extent that it became unmeasurable. Easily peeled off.

In addition, as can be seen from Table 2, by using the adhesive sheets (1) and (2) of Examples 1 and 2, while maintaining the attached state of the non-selected singulated wafers to the adhesive sheet, it can be heated by heating. Only selected individual wafers are peeled off.

1a, 1b‧‧‧Single-sided adhesive sheet 2a, 2b‧‧‧Double-sided adhesive sheet 7‧‧‧Processing inspection object 7a‧‧‧Adherent to be peeled off 11‧‧‧thermally expandable substrate 121‧‧‧ Adhesive layer (X1) 121a‧‧‧adhesive surface 122‧‧‧adhesive layer (X2) 122a‧‧‧adhesive surface 131, 132‧‧‧adhesive layer (X2) Release material

14: Hard support body

15: Adsorption nozzle

20: Frame members

21: opening

30: Adhesive surface of the peripheral part of the semiconductor wafer

40: Packaging material

41: hardened packaging material

50: Encapsulation

50a: Individualized packages

60: fixed means

80: heating means

81: heating part

CP: semiconductor wafer

W1: circuit surface

Fig. 1 is a cross-sectional model view of an adhesive sheet showing an example of the structure of a single-sided adhesive sheet used in a heat-peeling method for processing an inspection object according to the present invention. Fig. 2 is a cross-sectional model view of an adhesive sheet showing an example of the structure of a double-sided adhesive sheet used in a heat-peeling method for processing an inspection object according to the present invention. Fig. 3 is a model diagram showing an example of using a single-sided adhesive sheet in step (I) of the heat-peeling method for processing an inspection object according to the present invention. Fig. 4 is a model diagram showing an example of using a double-sided adhesive sheet in step (I) of the heat-peeling method for processing an inspection object according to the present invention. Fig. 5 is a model diagram showing an example of using a single-sided adhesive sheet in step (II) of the heat-peeling method for processing an inspection object according to the present invention. Fig. 6 is a model diagram showing an example of using a double-sided adhesive sheet in step (II) of the heat-peeling method for processing an inspection object according to the present invention. Fig. 7 is a cross-sectional model diagram showing an example of steps (I-A1) to (I-A3) of one aspect of the method of heat-peeling the object to be inspected according to the present invention. Fig. 8 is a cross-sectional model diagram showing an example of steps (I-B1) to (I-B3) of an aspect of the heat-peeling method for processing an inspection object according to the present invention.

7‧‧‧Processing inspection object

7a‧‧‧Adheres that should be peeled off

11‧‧‧Thermal expansion substrate

15‧‧‧Adsorption nozzle

20‧‧‧Frame member

21‧‧‧Opening of frame member

60‧‧‧fixed means

80‧‧‧Heating means

81‧‧‧Heating Department

121‧‧‧Adhesive layer (X1)

Claims (15)

A heat peeling method for processing an inspection object, characterized by having the following steps (I) and (II), step (I): an adhesive sheet on a non-adhesive thermally expandable substrate and an adhesive layer (X1) The step of attaching a plurality of objects to be processed and inspected on the adhesive surface of the adhesive layer (X1), the non-adhesive heat-expandable substrate containing resin and heat-expandable particles, step (II): a part of the above-mentioned heat-expandable substrate A step of selectively peeling off a part of the plurality of processed inspection objects by heating to a temperature above which the thermally expandable particles expand. The method of claim 1, wherein the aforementioned step (I) has the following steps (I-1) to (I-2), step (I-1): on the adhesive surface of the adhesive layer (X1) of the aforementioned adhesive sheet Step (I-2): a step of attaching the pre-segmented processed inspection object on the aforementioned adhesive surface into individual sheets. The method according to claim 1 or 2, wherein the aforementioned adhesive sheet is a double-sided adhesive sheet having an adhesive layer (X2) on the side opposite to the side where the adhesive layer (X1) is laminated on the aforementioned heat-expandable substrate, wherein It is used by sticking a hard support on the adhesive surface of the adhesive layer (X2) of the aforementioned double-sided adhesive sheet. As the method of claim 3, wherein step (I) has the following steps (I-A1) ~ (I-A3), step (I-A1): setting a plurality of semiconductor wafers between adjacent semiconductor wafers The step of placing it on the adhesive surface of the adhesive layer (X1) at the same time, the step (I-A2): covering the aforementioned plurality of semiconductor chips and the adhesive surfaces of the peripheral parts of the aforementioned plurality of semiconductor chips with a packaging material, so that The step of hardening the packaging material to obtain a package in which the plurality of semiconductor chips are packaged in the hardening packaging material, step (I-A3): the step of singulating the package body by the semiconductor chip unit. The method according to claim 1 or 2, wherein the adhesive sheet is used by attaching a frame member having an opening on the adhesive surface of the adhesive layer (X1). As the method of claim 5, wherein step (I) has the following steps (I-B1) ~ (I-B3), step (I-B1): a plurality of semiconductor wafers are arranged between the adjacent aforementioned semiconductor wafers The step of simultaneously placing it on the adhesive surface of the adhesive layer (X1) exposed in the aforementioned opening of the aforementioned frame member, step (I-B2): covering the aforementioned plurality of semiconductor wafers and the aforementioned plurality of semiconductor chips with an encapsulation material The adhesive surface of the peripheral part of the chip hardens the aforementioned encapsulation material, so that the aforementioned plurality of semiconductor chips are packaged in the hardened encapsulation material. The step of forming the package, step (I-B3): a step of singulating the package by the unit of the semiconductor wafer. The method according to claim 1 or 2, wherein the heating in step (II) is performed on the side opposite to the side where the thermally expandable substrate is laminated with the adhesive layer (X1). The method according to claim 1 or 2, wherein the thermally expandable substrate satisfies the following requirement (1), ‧requirement (1): the storage modulus E'(23) at 23°C is 1.0×10 ⁶ Pa or more. The method according to claim 1 or 2, wherein the thermally expandable base material satisfies the following requirement (2), ‧requirement (2): the storage modulus E'(100) at 100°C is 2.0×10 ⁵ Pa or more. The method according to claim 1 or 2, wherein the expansion start temperature (t) of the aforementioned heat-expandable particles is 120-250°C, and the aforementioned heat-expandable substrate satisfies the following requirement (3), ‧requirement (3): expansion start temperature The storage modulus E'(t) in (t) is 1.0×10 ⁷ Pa or less. The method according to claim 1 or 2, wherein the storage shear modulus G'(23) of the adhesive layer (X1) at 23°C is 1.0×10 ⁴ ~1.0×10 ⁸ Pa. The method according to claim 1 or 2, wherein the ratio of the thickness of the thermally expandable substrate to the thickness of the adhesive layer (X1) at 23°C (thermally expandable substrate/adhesive layer (X1)) is 0.2 or more. The method according to claim 1 or 2, wherein the thickness of the thermally expandable substrate at 23°C is 10-1000 μm, and the thickness of the adhesive layer (X1) is 1-60 μm. The method according to claim 1 or 2, wherein the probe viscosity value of the surface of the thermally expandable substrate is less than 50mN/5mm

. The method according to claim 1 or 2, wherein the average particle diameter of the thermally expandable particles before expansion at 23°C is 3-100 μm.

Images