WO2019235217A1

WO2019235217A1 - Method for producing cured sealant

Info

Publication number: WO2019235217A1
Application number: PCT/JP2019/020190
Authority: WO
Inventors: 忠知山田; 真也田久
Original assignee: リンテック株式会社
Priority date: 2018-06-08
Filing date: 2019-05-22
Publication date: 2019-12-12
Also published as: CN112262459A; JP7267272B2; KR20210018272A; JPWO2019235217A1; TW202000822A; TWI816796B

Abstract

This method for producing a cured sealant by using an adhesive sheet having: a base material (Y) equipped with a non-expandable base material layer (Y2) and an expandable base material layer (Y1) that contains expandable particles; and a first adhesive layer (X1) and a second adhesive layer (X2). The method comprises steps (1)-(3). Step (1): A step for attaching the adhesive surface of the first adhesive layer (X1) to a hard support body, and placing an object to be sealed on a portion of the adhesive surface of the second adhesive layer (X2). Step (2): A step for covering the object to be sealed and the adhesive surface of the second adhesive layer (X2) with a sealant, and then letting said sealant to cure so as to obtain a cured sealant. Step (3): A step for causing the expandable particles to expand so as to separate the hard support body and the first adhesive layer (X1) from each other at an interface P therebetween.

Description

Method for producing cured sealing body

The present invention relates to a method for producing a cured encapsulant.

The pressure-sensitive adhesive sheet is used not only for semi-permanently fixing members but also for temporarily fixing the target members when processing or inspecting building materials, interior materials, electronic parts, etc. There is a case.
Such a pressure-sensitive adhesive sheet for temporarily fixing is required to satisfy both adhesiveness at the time of use and peelability after use.

For example, Patent Document 1 discloses a heat-peelable pressure-sensitive adhesive sheet for temporary fixing at the time of cutting an electronic component, in which a heat-expandable pressure-sensitive adhesive layer containing heat-expandable microspheres is provided on at least one surface of a substrate. ing.
This heat-peelable pressure-sensitive adhesive sheet adjusts the maximum particle diameter of the heat-expandable microspheres with respect to the thickness of the heat-expandable pressure-sensitive adhesive layer, and calculates the centerline average roughness of the surface of the heat-expandable pressure-sensitive adhesive layer before heating. It is adjusted to 0.4 μm or less.
In Patent Document 1, since the heat-peelable pressure-sensitive adhesive sheet can sufficiently secure a bonding area with an adherend when an electronic component is cut, it can exhibit adhesiveness that can prevent adhesion failure such as chip jumping, Then, after use, there is a description that if the thermally expandable microspheres are expanded by heating, the contact area with the adherend can be reduced and can be easily peeled off.

Japanese Patent No. 3594853

In recent years, electronic devices have been reduced in size, thickness, and density, and semiconductor devices mounted on electronic devices are also required to be reduced in size, thickness, and density. FOWLP (Fan out Wafer Level Package) has attracted attention as a semiconductor package technology that can meet such demands.
FOWLP provides a rewiring layer on the surface of a semiconductor chip side of a hardened sealing body formed by sealing a plurality of semiconductor chips arranged at a predetermined interval with a sealing material, and soldering is performed via the rewiring layer. A semiconductor package in which a ball and a semiconductor chip are electrically connected.
FOWLP can be applied to an application where the number of terminals is larger than the area of the semiconductor chip because the terminals, which are solder balls, can be expanded to the outside of the semiconductor chip (Fan out).

By the way, FOWLP is a method in which a circuit surface of a semiconductor chip is placed on an adhesive sheet, and a sealing resin having fluidity heated to around 100 ° C. is filled around the semiconductor chip, heated, and sealed. Forming a layer composed of resin or laminating a sealing resin film on a semiconductor chip, heating and laminating, and removing the adhesive sheet and exposing the semiconductor chip side In general, it is manufactured through a step of forming a redistribution layer and solder balls on the surface of the substrate.
In the sealing step of the above FOWLP manufacturing method, for example, as described in Patent Document 1, a heat-peelable adhesive in which a thermally expandable adhesive layer containing thermally expandable microspheres is provided on a substrate. It is also possible to use a sheet.

However, since the heat-expandable pressure-sensitive adhesive layer of the heat-peelable pressure-sensitive adhesive sheet described in Patent Document 1 contains heat-expandable microspheres, it has a sealing process, etc., compared to an adhesive layer that does not contain heat-expandable microspheres. There is a concern about the decrease in adhesive strength during the processing and inspection.
For example, the decrease in the adhesive strength during the sealing process is caused by the displacement of the semiconductor chip placed on the adhesive layer or the sealing resin invading at the bonding interface between the semiconductor chip and the adhesive sheet. This causes a problem such as resin adhering to the circuit surface.
In particular, the elastic modulus of the heat-expandable pressure-sensitive adhesive layer is generally adjusted to be low so that irregularities are easily formed on the surface during expansion of the heat-expandable microspheres. There is a concern that the semiconductor chip placed on the surface of the adhesive layer is likely to be displaced during the sealing process.

The occurrence of misalignment of the semiconductor chip and the adhesion of the sealing resin to the circuit surface of the semiconductor chip cause a decrease in yield in the manufacture of the semiconductor device. Such a problem may occur also in an object to be sealed other than a semiconductor chip.
Therefore, occurrence of misalignment of a sealing object such as a semiconductor chip that may occur when obtaining a cured sealing body, and adhesion of sealing resin to an exposed surface of the sealing object such as a circuit surface of a semiconductor chip Thus, there is a demand for a method for producing a cured encapsulant that can suppress such harmful effects.

Further, in the manufacture of FOWLP, it is common to fix the support and the semiconductor chip via a double-sided PSA sheet having adhesive layers on both sides of the substrate. For example, in the heat-peelable pressure-sensitive adhesive sheet described in Patent Document 1, as a double-sided pressure-sensitive adhesive sheet in which a heat-expandable pressure-sensitive adhesive layer and a pressure-sensitive adhesive layer are provided on both surfaces of a substrate, a semiconductor chip is provided on the heat-expandable pressure-sensitive adhesive layer side. It is mounted, and the adhesive layer side is attached to a support, and various processes such as a sealing process are usually performed.
However, when the above heat-peelable pressure-sensitive adhesive sheet is used, it is separated at the interface between the heat-expandable pressure-sensitive adhesive layer and the cured sealing material, and the above-mentioned double-sided pressure-sensitive adhesive sheet remains adhered to the support. When the double-sided PSA sheet is removed from the substrate, a part of the PSA layer of the PSA sheet may remain on the adherend. In such a case, it is necessary to perform a cleaning process of the support, which causes a reduction in productivity.

On the other hand, when using the above double-sided pressure-sensitive adhesive sheet, a method of sticking the thermally expandable pressure-sensitive adhesive layer to the support is also conceivable, and the peelability when removing the double-sided pressure-sensitive adhesive sheet from the support after the sealing step is improved. It seems to be.
However, the heat-expandable adhesive layer after the heat-expandable microspheres are expanded is very brittle.
Therefore, the cured sealing body with the double-sided pressure-sensitive adhesive sheet after peeling from the support is thermally expandable when transported or processed in the next process because this thermally expandable pressure-sensitive adhesive layer is located in the outermost layer. Part of the pressure-sensitive adhesive layer is easily dropped off or the heat-expandable pressure-sensitive adhesive layer is easily peeled off. If the dropped heat-expandable adhesive layer adheres to various devices in the production environment and contaminates the device, the device needs to be cleaned, which causes a decrease in productivity.
That is, in the production of a cured encapsulated body, it is also required to suppress the contamination in the production environment, do not require a cleaning step, and improve productivity.

In the present invention, when a sealing object is obtained by using a sealing material to obtain a cured sealing body, occurrence of positional deviation of the sealing object and adhesion of the sealing resin to the exposed surface of the sealing object It is an object of the present invention to provide a method for producing a cured encapsulant that can effectively suppress adverse effects and improve yield, and can suppress contamination in a production environment and improve productivity.

In the process of producing a cured sealing body using a sealing material as a sealing object, the present inventors include a base material provided with at least an inflatable base material layer containing inflatable particles and a non-inflatable base material layer. It has been found that the above-mentioned problems can be solved by using a pressure-sensitive adhesive sheet having a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer, which are non-intumescent pressure-sensitive adhesive layers, on both sides.

That is, the present invention relates to the following [1] to [10].
[1] A substrate (Y) comprising at least an expandable substrate layer (Y1) containing expandable particles and a non-expandable substrate layer (Y2);
On both surfaces of the base material (Y), the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2), which are non-intumescent pressure-sensitive adhesive layers,
By the expansion of the expandable particles, unevenness can occur on the adhesive surface of the first pressure-sensitive adhesive layer (X1), using a pressure-sensitive adhesive sheet, a method for producing a cured sealing body,
A method for producing a cured encapsulant comprising the following steps (1) to (3).
-Process (1): The process of sticking the adhesion surface of a 1st adhesive layer (X1) on a hard support body, and mounting a sealing target object on a part of adhesion surface of a 2nd adhesive layer (X2). .
Step (2): The sealing object and the adhesive surface of the second pressure-sensitive adhesive layer (X2) at least in the periphery of the sealing object are covered with a sealing material, and the sealing material is cured. And the process of obtaining the hardening sealing body formed by sealing the said sealing target object with the said sealing material.
Step (3): The expandable particles are expanded and the hard support and the first pressure-sensitive adhesive layer (X1) are stacked while the cured sealing body is laminated on the second pressure-sensitive adhesive layer (X2). Separating at the interface P.
[2] The pressure-sensitive adhesive sheet has a first pressure-sensitive adhesive layer (X1) on the base material (Y) on the side of the expandable base material layer (Y1), and the base material (Y) has the non-expandable group. The manufacturing method of the hardening sealing body as described in said [1] which has a said 2nd adhesive layer (X2) in the material layer (Y2) side.
[3] The base material (Y) is a non-expandable base material provided on the expandable base material layer (Y1) and the first adhesive layer (X1) side of the expandable base material layer (Y1). A layer (Y2-1) and a non-intumescent substrate layer (Y2-2) provided on the second adhesive layer (X2) side of the expandable substrate layer (Y1),
The storage elastic modulus E ′ of the non-expandable base layer (Y2-1) when the expandable particles expand is determined by the storage modulus of the non-expandable base layer (Y2-2) when the expandable particles expand. The manufacturing method of the hardening sealing body as described in said [1] or [2] lower than elastic modulus E '.
[4] The non-expandable base layer (Y2) is present at a position farther from the first pressure-sensitive adhesive layer (X1) than the expandable base layer (Y1), and the expandable base layer The non-intumescent substrate layer (Y2) does not exist between the layer (Y1) and the first pressure-sensitive adhesive layer (X1),
The storage elastic modulus E ′ of the non-expandable base layer (Y2) when the expandable particles expand is the storage elastic modulus E of the expandable base layer (Y1) when the expandable particles expand. The manufacturing method of the hardening sealing body as described in said [1] or [2] larger than '.
[5] The cured encapsulant according to any one of the above [1] to [4], wherein when the expandable particles are expanded in step (3), they are not separated between the layers constituting the pressure-sensitive adhesive sheet. Manufacturing method.
[6] The method for producing a cured encapsulant according to any one of [1] to [5] above, wherein the expandable particles are thermally expandable particles having an expansion start temperature (t) of 60 to 270 ° C.
[7] The expansion according to [6], wherein the expansion of the thermally expandable particles is performed by a heat treatment between “expansion start temperature (t) + 10 ° C.” to “expansion start temperature (t) + 60 ° C.” Manufacturing method of the cured sealing body.
[8] Storage of the thermally expandable substrate layer (Y1-1) at 23 ° C., wherein the expandable substrate layer (Y1) is a thermally expandable substrate layer (Y1-1) containing the thermally expandable particles. The method for producing a cured sealed body according to the above [6] or [7], wherein the elastic modulus E ′ (23) is 1.0 × 10 ⁶ Pa or more.
[9] The method for producing a cured encapsulant according to any one of the above [1] to [8], wherein the volume change rate (%) of the non-expandable base material layer (Y2) is less than 2% by volume.
[10] The method for producing a cured encapsulant according to any one of [1] to [9], wherein the object to be encapsulated is a semiconductor chip.

According to the method for producing a cured sealed body of the present invention, when obtaining a cured sealed body with a sealing material, the occurrence of positional deviation of the sealed object or the exposed surface of the sealed object. It is possible to effectively suppress adverse effects such as adhesion of the sealing resin to the substrate and improve the yield, and to suppress contamination in the manufacturing environment and improve productivity.

It is a cross-sectional schematic diagram of the said adhesive sheet which shows an example of a structure of the adhesive sheet used with the manufacturing method of the semiconductor chip of this invention. FIG. 6 is a schematic cross-sectional view in steps (1) to (3) of the method for manufacturing a semiconductor chip of the present invention.

In the present specification, the determination as to whether the target layer is an “expandable layer” or “non-expandable layer” is as follows: Judgment is made based on the volume change rate calculated from the equation.
Volume change rate (%) = {(volume of the layer after treatment−volume of the layer before treatment) / volume of the layer before treatment} × 100
That is, if the volume resistivity is 5% by volume or more, it is determined that the layer is an “expandable layer”, and if the volume change rate is less than 5% by volume, the layer is a “non-expandable layer”. It is judged that.
As the “treatment for expanding”, for example, when the expandable particles are thermally expandable particles, a heat treatment for 3 minutes may be performed at the expansion start temperature (t) of the thermally expandable particles. .

In the present specification, the “active ingredient” refers to a component excluding a diluent solvent among components contained in a target composition.
The mass average molecular weight (Mw) is a value in terms of standard polystyrene measured by a gel permeation chromatography (GPC) method, specifically a value measured based on the method described in the examples.

In the present specification, for example, “(meth) acrylic acid” indicates both “acrylic acid” and “methacrylic acid”, and the same applies to other similar terms.
Moreover, about the preferable numerical range (for example, range, such as content), the lower limit value and upper limit value which were described in steps can be combined independently, respectively. For example, from the description “preferably 10 to 90, more preferably 30 to 60”, “preferable lower limit (10)” and “more preferable upper limit (60)” are combined to obtain “10 to 60”. You can also.

[Method for producing cured sealing body of the present invention]
The method for producing a cured encapsulant of the present invention (hereinafter also simply referred to as “the production method of the present invention”) comprises an expandable base material layer (Y1) and a non-expandable base material layer (Y2) containing expandable particles. It has at least a base material (Y) and a first pressure-sensitive adhesive layer (X1) and a second pressure-sensitive adhesive layer (X2) that are non-expandable pressure-sensitive adhesive layers on both sides of the base material (Y). This is a method for producing a cured encapsulant using an adhesive sheet, in which irregularities can occur on the adhesive surface of the first adhesive layer (X1) due to the expansion of the expandable particles.
The production method of the present invention includes the following steps (1) to (3).
-Process (1): The process of sticking the adhesion surface of a 1st adhesive layer (X1) on a hard support body, and mounting a sealing target object on a part of adhesion surface of a 2nd adhesive layer (X2). .
Step (2): The sealing object and the adhesive surface of the second pressure-sensitive adhesive layer (X2) at least in the periphery of the sealing object are covered with a sealing material, and the sealing material is cured. And the process of obtaining the hardening sealing body formed by sealing the said sealing target object with the said sealing material.
Step (3): The expandable particles are expanded and the hard support and the first pressure-sensitive adhesive layer (X1) are stacked while the cured sealing body is laminated on the second pressure-sensitive adhesive layer (X2). Separating at the interface P.

[Configuration of pressure-sensitive adhesive sheet used in the production method of the present invention]
FIG. 1 is a schematic cross-sectional view of the pressure-sensitive adhesive sheet showing an example of the configuration of the pressure-sensitive adhesive sheet used in the production method of the present invention.
The pressure-sensitive adhesive sheet used in the production method of the present invention includes a base (Y) having at least an expandable base layer (Y1) and a non-expandable base layer (Y2) as shown in FIG. The adhesive sheet 1a which has a 1st adhesive layer (X1) and a 2nd adhesive layer (X2) which are non-expandable adhesive layers on both surfaces of a material (Y), respectively is mentioned.

Although the base material (Y) which the adhesive sheet 1a shown to Fig.1 (a) has has the structure which the expandable base material layer (Y1) and the non-expandable base material layer (Y2) laminated | stacked directly, The base material (Y) may have a configuration other than this.
For example, like the base material (Y) of the pressure-sensitive adhesive sheet 1b shown in FIG. 1 (b), the first non-thermally expandable base material layer (Y2-1) and the first non-expandable base material layer (Y2-1) and 2 A configuration in which a non-thermally expandable base material layer (Y2-2) is provided may be employed.

In the pressure-sensitive adhesive sheet used in one embodiment of the present invention, a release material may be further laminated on the pressure-sensitive adhesive surface of the first pressure-sensitive adhesive layer (X1) and the pressure-sensitive adhesive surface of the second pressure-sensitive adhesive layer (X2).
In the structure, a structure in which a release material having a release treatment applied to both sides is laminated on one adhesive surface of the first adhesive layer (X1) and the second adhesive layer (X2) is wound in a roll shape. It is good.
These release materials are provided to protect the adhesive surfaces of the first adhesive layer (X1) and the second adhesive layer (X2), and are removed when the adhesive sheet is used.

Also, for example, in the pressure-sensitive adhesive sheet 1a shown in FIG. 1A, the peeling force when peeling the release material laminated on the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2) are laminated. When the peeling force at the time of peeling off the release material is about the same, the adhesive sheet 1a is divided along with the two release materials and peeled off by pulling both release materials outward. This may cause a negative effect.
For this reason, the release material laminated on the first pressure-sensitive adhesive layer (X1) and the release material laminated on the second pressure-sensitive adhesive layer (X2) have different peeling forces from the pressure-sensitive adhesive layer attached to each other. It is preferable to use two types of designed release materials.

By the way, the pressure-sensitive adhesive sheet used in the production method of the present invention is adjusted so that irregularities can be generated on the pressure-sensitive adhesive surface of the first pressure-sensitive adhesive layer (X1) by the expansion of the expandable particles.
For example, in the pressure-sensitive adhesive sheet 1a shown in FIG. 1A, a first pressure-sensitive adhesive layer (X1) that is a non-expandable pressure-sensitive adhesive layer is laminated on an expandable base material layer (Y1) containing expandable particles. Moreover, it has the structure which laminated | stacked the 2nd adhesive layer (X2) which is a non-expandable adhesive layer on the non-expandable base material layer (Y2).
In the pressure-sensitive adhesive sheet 1a, when the expandable particles in the expandable base material layer (Y1) expand, the surface of the expandable base material layer (Y1) is uneven, and the first pressure-sensitive adhesive layer is in contact with the surface. (X1) is pushed up by the irregularities, and as a result, irregularities may also occur on the adhesive surface of the first pressure-sensitive adhesive layer (X1).
In the production method of the present invention, as described in the above step (1), the adhesive surface of the first adhesive layer (X1) is affixed to a hard support.
And in said process (3), when an expandable particle is expanded, since an unevenness | corrugation arises in the adhesive surface of a 1st adhesive layer (X1) and a contact area with a hard support body decreases, a hard support body And the first pressure-sensitive adhesive layer (X1) can be easily separated together with a slight force at the interface P.
Further, when the expandable particles are expanded, they can be easily separated by a small force at the interface between the expandable substrate layer (Y1) and the non-expandable substrate layer (Y2). You may adjust.

On the other hand, as described above, the sealing object is placed on the adhesive surface of the second pressure-sensitive adhesive layer (X2). In step (2), the placed sealing object and Then, the second pressure-sensitive adhesive layer (X2) at the periphery of the object to be sealed is covered with a sealing material, and the sealing material is cured to form a cured sealing body. And as stipulated in the above-mentioned step (3), when the expandable particles are expanded, the hard support and the first pressure-sensitive adhesive remain stacked on the second pressure-sensitive adhesive layer (X2). They are separated at the interface P with the agent layer (X1).
That is, when separating from the hard support, the plurality of semiconductor chips are required to be held on the second pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet.
Therefore, the pressure-sensitive adhesive surface of the second pressure-sensitive adhesive layer (X2) is suppressed from forming irregularities so that the adhesive force sufficient to hold the cured sealing body can be maintained by the expansion of the expandable particles. It is preferable that the adjustment is performed.

For example, in the pressure-sensitive adhesive sheet 1a shown in FIG. 1 (a), the non-intumescent base material layer (Y2) is provided on the surface of the expandable base material layer (Y1) opposite to the first pressure-sensitive adhesive layer (X1). The second pressure-sensitive adhesive layer (X2) is laminated on the surface of the non-expandable base material layer (Y2).
In the pressure-sensitive adhesive sheet 1a, when the expandable particles are expanded, the non-expandable base layer (Y2) is present. Therefore, the stress from the expandable base layer (Y1) side due to expansion of the expandable particles is A non-expandable base material layer (Y2) absorbs. As a result, the formation of irregularities on the adhesive surface of the second pressure-sensitive adhesive layer (X2) laminated on the non-expandable base material layer (Y2) is suppressed, and the cured sealed body is laminated on the adhesive surface. can do.

In the pressure-sensitive adhesive sheet 1b shown in FIG. 1B, when the expandable particles expand, the first non-expandable so that irregularities are formed on the pressure-sensitive adhesive surface of the first pressure-sensitive adhesive layer (X1). It is preferable to adjust the storage elastic modulus E ′ of the base material layer (Y2-1) to be low.
On the other hand, when the expandable particles expand, the second non-thermally expandable base material layer (Y2-2) is prevented from forming irregularities on the pressure-sensitive adhesive surface of the second pressure-sensitive adhesive layer (X2). The storage elastic modulus E ′ is preferably adjusted to be high.
That is, the storage elastic modulus E ′ of the first non-expandable base layer (Y2-1) when the expandable particles expand is equal to the second non-thermally expandable base layer (Y2) when the expandable particles expand. -2) is preferably adjusted to be lower than the storage elastic modulus E ′.

By the way, using a pressure-sensitive adhesive sheet having an expandable pressure-sensitive adhesive layer containing expandable particles as described in Patent Document 1, a sealing object is placed on the pressure-sensitive adhesive surface of the expandable pressure-sensitive adhesive layer and cured. When it is going to obtain a sealing body, since the expansible adhesive layer which has mounted the sealing target object contains expansible particle | grains, adhesive force tends to become inadequate.
Therefore, during the sealing step in the step (2), the sealing resin of the sealing material enters the bonding interface between the positional deviation of the sealing target and the sealing target and the expandable pressure-sensitive adhesive layer. There may be an adverse effect that the sealing resin adheres to the exposed surface of the object to be stopped (for example, the circuit surface of the semiconductor chip).

Also, using a double-sided pressure-sensitive adhesive sheet having an expandable pressure-sensitive adhesive layer on one surface of a substrate and a non-expandable pressure-sensitive adhesive layer on the other surface, the expandable pressure-sensitive adhesive layer is a hard support. A method of obtaining a cured sealing body by placing an object to be sealed on the non-intumescent pressure-sensitive adhesive layer is also conceivable.
However, since the adhesive force of the expandable pressure-sensitive adhesive layer tends to be insufficient, and the sealing object is not sufficiently fixed to the hard support, the sealing object placed on the non-expandable pressure-sensitive adhesive layer However, it is easy to move when covered with a sealing material. Therefore, in the sealing process, adverse effects such as displacement of the sealing object and adhesion of the sealing resin to the exposed surface of the sealing object are likely to occur.

It is also conceivable to avoid the above-mentioned adverse effects by selecting an adhesive resin and making the expandable adhesive layer have a high adhesive force.
However, when the expandable pressure-sensitive adhesive layer has a high adhesive force, depending on the type of pressure-sensitive resin contained in the expandable pressure-sensitive adhesive layer, the expansion of the expandable particles becomes insufficient, and a treatment for expanding the expandable particles is performed. Even if it goes, it may become difficult to peel easily at once.
That is, when a sealing object is placed on an expandable pressure-sensitive adhesive layer having a high adhesive strength, the formed cured sealing body may be difficult to peel from the expandable pressure-sensitive adhesive layer. In addition, there may be a problem that a part of the expandable pressure-sensitive adhesive layer remains in the cured sealing body.

In addition, when an expandable pressure-sensitive adhesive layer having a high adhesive strength is applied to a hard support, the pressure-sensitive adhesive is applied to the surface of the hard support when the double-sided pressure-sensitive adhesive sheet is peeled from the hard support by expanding the expandable particles. A part of the layer may remain, and it is necessary to perform a cleaning process of the support, which causes a decrease in productivity.

In addition, the expandable pressure-sensitive adhesive layer after expansion of the expandable particles is very brittle. In a cured sealing body with a double-sided PSA sheet from a hard support, the expandable pressure-sensitive adhesive layer is located in the outermost layer. Part of the agent layer is likely to fall off or the expandable pressure-sensitive adhesive layer is easily peeled off.
When the dropped expandable pressure-sensitive adhesive layer adheres to various devices in the production environment and contaminates the device, the device needs to be cleaned, which causes a decrease in productivity.

On the other hand, the pressure-sensitive adhesive sheet used in the production method of the present invention has a base material (Y) including at least an inflatable base material layer (Y1) containing inflatable particles and a non-inflatable base material layer (Y2), and is inflated. When the adhesive particles expand, the adhesive surface of the first pressure-sensitive adhesive layer (X1) is adjusted so that irregularities are formed.
Therefore, the freedom degree of selection of the adhesive composition which is a forming material of the 1st adhesive layer (X1) and the 2nd adhesive layer (X2) is also high.
That is, unlike the expandable pressure-sensitive adhesive layer in which the restriction of the pressure-sensitive adhesive resin to be used as described above is imposed, the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive are not considered without considering the expandability of the expandable particles. It is possible to select the adhesive resin used for the agent layer (X2).
In addition, the first pressure-sensitive adhesive layer (X1) to be attached to the hard support is a non-expandable pressure-sensitive adhesive layer and does not need to contain expandable particles, and therefore can be sufficiently fixed to the hard support. In addition, it is possible to effectively suppress adverse effects such as misalignment of the sealing object and adhesion of the sealing resin to the exposed surface of the sealing object due to insufficient fixation between the sealing object and the hard support.

Furthermore, when separating the hard support and the attached adhesive sheet, they can be easily separated together, and contamination of the hard support after separation can be effectively suppressed.

In addition, in the cured sealed body with the pressure-sensitive adhesive sheet after separation, the expandable base material layer (Y1) containing the expanded particles after expansion is not located at least in the outermost layer, and the pressure-sensitive adhesive layer It has a certain degree of strength as compared with the case where it contains expansive particles. Therefore, dropping off of the expandable base material layer (Y1) after the expansion is difficult to occur.
Furthermore, in the cured sealed body with the pressure-sensitive adhesive sheet after separation, the first pressure-sensitive adhesive layer (X1) located in the outermost layer is a non-expandable pressure-sensitive adhesive layer and does not need to contain expandable particles. Defects such as dropping of one adhesive layer (X1) are unlikely to occur.
Therefore, in the manufacturing method of the present invention, since contamination within the manufacturing environment can be effectively suppressed, there is no need for a cleaning step accompanying the contamination, and excellent productivity can be exhibited.

[Various physical properties of adhesive sheet]
The pressure-sensitive adhesive sheet used in one embodiment of the present invention has irregularities on the pressure-sensitive adhesive surface of the first pressure-sensitive adhesive layer (X1) attached to the hard support due to the expansion of the expandable particles, and the hard support and the first pressure-sensitive adhesive. At the interface P with the layer (X1), separation can be easily performed at a time with a slight force.
Here, in the pressure-sensitive adhesive sheet used in one embodiment of the present invention, the peeling force (F ₁ ) when the expandable particles are expanded and separated at the interface P is usually 0 to 2000 mN / 25 mm, preferably 0 to 1000 mN / It is 25 mm, more preferably 0 to 150 mN / 25 mm, still more preferably 0 to 100 mN / 25 mm, and still more preferably 0 to 50 mN / 25 mm.
Note that the peel force (F ₁₎ is in the case of 0 mN / 25 mm, even trying to measure the peel strength by the method described in Example, includes the case where the measurement impossible because peel strength is too small.

On the other hand, before the expansion of the expandable particles, when obtaining a cured sealed body of the sealing object with a sealing material, occurrence of positional deviation of the sealing object or the exposed surface of the sealing object From the viewpoint of effectively suppressing adverse effects such as adhesion of the sealing resin and improving the yield, it is preferable that the first adhesive layer (X1) has a higher adhesive force.
From the above viewpoint, in the pressure-sensitive adhesive sheet used in one embodiment of the present invention, the peeling force (F ₀ ) when separating at the interface P before the expansion of the expandable particles is preferably 0.05 to 10.0 N / 25 mm. More preferably, it is 0.1 to 8.0 N / 25 mm, still more preferably 0.15 to 6.0 N / 25 mm, and still more preferably 0.2 to 4.0 N / 25 mm.
Incidentally, the release force (F ₀₎ can also be regarded as the adhesive strength of the first adhesive layer to the rigid support member (X1).

In the pressure-sensitive adhesive sheet used in one embodiment of the present invention, the ratio [(F ₁ ) / (F ₀ )] between the peel force (F ₁ ) and the peel force (F ₀ ) is preferably 0 to 0.9, more preferably Is 0 to 0.8, more preferably 0 to 0.5, and still more preferably 0 to 0.2.

The release force (F ₁₎ is a value measured under the environment when the expandable particles are expanded. For example, when the expandable particles are thermally expandable particles, the temperature condition for measuring the peel force (F ₁ ) may be equal to or higher than the expansion start temperature (t) of the thermally expandable particles.
On the other hand, the temperature condition for measuring the peeling force (F ₀ ) may be any temperature at which the expandable particles do not expand, and is basically room temperature (23 ° C.).
However, more specific measurement conditions and measurement methods for the peel force (F ₁ ) and the peel force (F ₀ ) are based on the methods described in the examples.

In the pressure-sensitive adhesive sheet used in one embodiment of the present invention, the adhesive strength of the second pressure-sensitive adhesive layer (X2) at room temperature (23 ° C.) is preferably 0.1 to 10.0 N / 25 mm, more preferably 0. The range is from 0.2 to 8.0 N / 25 mm, more preferably from 0.4 to 6.0 N / 25 mm, and still more preferably from 0.5 to 4.0 N / 25 mm.
In the present specification, the adhesive strength of the second pressure-sensitive adhesive layer (X2) means a value measured by the method described in Examples.
Hereinafter, each layer which comprises the adhesive sheet used by 1 aspect of this invention is demonstrated.

<Base material (Y)>
The base material (Y) included in the pressure-sensitive adhesive sheet used in one embodiment of the present invention includes at least an expandable base material layer (Y1) containing inflatable particles and a non-expandable base material layer (Y2).
Moreover, as a base material (Y), like the adhesive sheet 1a shown to Fig.1 (a), an expandable base material layer (Y1) and a non-expandable base material layer (Y2) are each laminated | stacked one by one. As in the pressure-sensitive adhesive sheet 1b shown in FIG. 1B, the first non-thermally expandable base layer (Y2-1) and the second non-expandable base layer (Y2-1) are formed on both sides of the expandable base layer (Y1). A configuration in which a non-thermally expandable base material layer (Y2-2) is provided may be employed.

In addition, the base material (Y) included in the pressure-sensitive adhesive sheet used in one embodiment of the present invention has a configuration in which an adhesive layer is provided between the inflatable base material layer (Y1) and the non-inflatable base material layer (Y2). May be.
For example, in the case of the configuration of the pressure-sensitive adhesive sheet 1b shown in FIG. 1B, the expandable substrate layer (Y1), the first non-thermally expandable substrate layer (Y2-1), and / or the second non-thermally expandable layer An adhesive layer may be provided between the conductive base material layer (Y2-2).
By providing the adhesive layer, the interlayer adhesion between the expandable base material layer (Y1) and the non-expandable base material layer (Y2) can be improved.
The adhesive layer can be formed from a general adhesive or a pressure-sensitive adhesive composition that is a material for forming the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2).

In one embodiment of the present invention, the expansion of the expandable particles causes unevenness on the adhesive surface of the first pressure-sensitive adhesive layer (X1), while suppressing the formation of unevenness on the adhesive surface of the second pressure-sensitive adhesive layer (X2). From the viewpoint of forming a pressure-sensitive adhesive sheet, it is preferable that the base material (Y) is provided with at least an inflatable base material layer (Y1) and a non-expandable base material layer (Y2) on the outermost surface. .
As the said aspect, the base material (Y) which the adhesive sheet 1a shown to Fig.1 (a) has, an expandable base material layer (Y1), an adhesive layer, and a non-expandable base material layer (Y2) in this order. The base material (Y) formed by laminating is mentioned.

The expandable substrate layer (Y1) and the non-expandable substrate layer (Y2) constituting the substrate (Y) are both non-adhesive layers.
In the present invention, the determination as to whether or not the layer is a non-adhesive layer is made if the probe tack value measured in accordance with JIS Z0237: 1991 is less than 50 mN / 5 mmφ with respect to the surface of the target layer. Is judged as a “non-sticky layer”.
The probe tack values on the surfaces of the expandable base material layer (Y1) and the non-expandable base material layer (Y2) of the pressure-sensitive adhesive sheet (I) used in one embodiment of the present invention are each independently usually less than 50 mN / 5 mmφ. However, it is preferably less than 30 mN / 5 mmφ, more preferably less than 10 mN / 5 mmφ, and even more preferably less than 5 mN / 5 mmφ.
In addition, in this specification, the specific measuring method of the probe tack value on the surface of a thermally expansible base material is based on the method as described in an Example.

In the pressure-sensitive adhesive sheet used in one embodiment of the present invention, the thickness of the substrate (Y) is preferably 15 to 2000 μm, more preferably 25 to 1500 μm, still more preferably 30 to 1000 μm, and still more preferably 40 to 500 μm. is there.

The thickness of the expandable substrate (Y1) before expansion of the expandable particles is preferably 10 to 1000 μm, more preferably 20 to 700 μm, still more preferably 25 to 500 μm, and still more preferably 30 to 300 μm.
The thickness of the non-expandable substrate (Y2) is preferably 10 to 1000 μm, more preferably 20 to 700 μm, still more preferably 25 to 500 μm, and still more preferably 30 to 300 μm.
In the present specification, for example, a plurality of expandable substrates (Y1) or non-expandable substrates (Y2) exist via other layers as in the adhesive sheet 1b shown in FIG. 1 (b). When doing, the thickness of said expansible base material (Y1) or a non-expandable base material (Y2) means the thickness per each layer.

In the pressure-sensitive adhesive sheet used in one embodiment of the present invention, the thickness ratio between the expandable base material layer (Y1) and the non-thermally expandable base material layer (Y2) before expansion of the expandable particles [(Y1) / ( Y2)] is preferably 0.02 to 200, more preferably 0.03 to 150, and still more preferably 0.05 to 100.

In the pressure-sensitive adhesive sheet used in one embodiment of the present invention, the expandable base material layer (Y1) before expansion of the expandable particles, and the first pressure-sensitive adhesive layer (X1) directly laminated with the expandable base material layer (Y1) The thickness ratio [(Y1) / (X1)] is preferably 0.2 or more, more preferably 0.5 or more, still more preferably 1.0 or more, and still more preferably 5.0 or more. Also, it is preferably 1000 or less, more preferably 200 or less, still more preferably 60 or less, and still more preferably 30 or less.

In the pressure-sensitive adhesive sheet used in one embodiment of the present invention, the thickness of the non-expandable base material layer (Y2) and the second pressure-sensitive adhesive layer (X2) directly laminated with the non-expandable base material layer (Y2). The ratio [(Y2) / (X2)] is preferably 0.1 or more, more preferably 0.2 or more, still more preferably 0.3 or more, and preferably 20 or less, more preferably 10 or less. More preferably, it is 5 or less.

Hereinafter, the expandable substrate layer (Y1) and the non-expandable substrate layer (Y2) constituting the substrate (Y) will be described.

<Expandable base material layer (Y1)>
The expandable substrate layer (Y1) constituting the substrate (Y) is a layer that contains expandable particles and can be expanded by a predetermined expansion treatment.
The content of the expandable particles in the expandable substrate layer (Y1) is preferably 1 to 40% by mass, more preferably 5%, based on the total mass (100% by mass) of the expandable substrate layer (Y1). It is ˜35% by mass, more preferably 10 to 30% by mass, and still more preferably 15 to 25% by mass.

In addition, from the viewpoint of improving interlayer adhesion between the expandable base material layer (Y1) and other layers to be laminated, the surface of the expandable base material layer (Y1) is a surface formed by an oxidation method, a roughening method, or the like. Treatment, easy adhesion treatment, or primer treatment may be performed.
Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromic acid treatment (wet), hot air treatment, ozone, and ultraviolet irradiation treatment. Examples of the unevenness method include sand blast method and solvent treatment method. Etc.

The expandable particles contained in the expandable substrate layer (Y1) may be any particles that expand by performing a predetermined treatment, such as thermally expandable particles that expand by heating at a predetermined temperature or higher, Examples include UV-expandable particles that absorb a predetermined amount of ultraviolet rays to generate gas and expand inside the particles.

The volume expansion coefficient of the expandable particles is preferably 1.5 to 100 times, more preferably 2 to 80 times, still more preferably 2.5 to 60 times, and still more preferably 3 to 40 times.

The average particle diameter of the expandable particles before expansion at 23 ° C. is preferably 3 to 100 μm, more preferably 4 to 70 μm, still more preferably 6 to 60 μm, and still more preferably 10 to 50 μm.
The average particle size of the expandable particles is the volume-median particle size (D ₅₀ ) and is measured using a laser diffraction particle size distribution measuring device (for example, product name “Mastersizer 3000” manufactured by Malvern). In the particle distribution of the expanded particles, it means a particle size corresponding to 50% of the cumulative volume frequency calculated from the smaller particle size of the expandable particles.

The 90% particle diameter (D ₉₀ ) of the expandable particles before expansion at 23 ° C. is preferably 10 to 150 μm, more preferably 20 to 100 μm, still more preferably 25 to 90 μm, and still more preferably 30 to 80 μm. .
The 90% particle size (D ₉₀ ) of the expandable particles is the particle distribution of the expandable particles measured using a laser diffraction particle size distribution measuring device (for example, product name “Mastersizer 3000” manufactured by Malvern). In FIG. 5, the particle size corresponding to 90% of the cumulative volume frequency calculated from the smaller particle size of the expandable particles.

In one embodiment of the present invention, the expandable particles are preferably thermally expandable particles having an expansion start temperature (t) of 60 to 270 ° C.
That is, the expandable substrate layer (Y1) is preferably a thermally expandable substrate layer (Y1-1) containing thermally expandable particles having an expansion start temperature (t) of 60 to 270 ° C. The conductive base material layer (Y1-1) more preferably satisfies the following requirement (1).
Requirement (1): The storage elastic modulus E ′ (t) of the thermally expandable substrate layer (Y1-1) at the expansion start temperature (t) of the thermally expandable particles is 1.0 × 10 ⁷ Pa It is as follows.
In the present specification, the storage elastic modulus E ′ of the thermally expandable base material layer (Y1-1) at a predetermined temperature means a value measured by the method described in the examples.

The requirement (1) can be said to be an index indicating the rigidity of the thermally expandable substrate layer (Y1-1) immediately before the thermally expandable particles expand.
That is, when the thermally expandable particles expand, if the thermally expandable substrate layer (Y1-1) is flexible enough to satisfy the above requirement (1), the thermally expandable substrate layer (Y1 As a result, unevenness is likely to be formed on the surface of -1), and unevenness is also likely to occur on the adhesive surface of the first pressure-sensitive adhesive layer (X1). As a result, it is possible to easily separate them with a slight force at the interface P between the hard support and the first pressure-sensitive adhesive layer (X1).

From the above viewpoint, the storage elastic modulus E ′ (t) defined by requirement (1) of the thermally expandable base material layer (Y1-1) is preferably 9.0 × 10 ⁶ Pa or less, more preferably 8.0. × 10 ⁶ Pa or less, more preferably 6.0 × 10 ⁶ Pa or less, and even more preferably 4.0 × 10 ⁶ Pa or less.
In addition, the flow of the expanded heat-expandable particles is suppressed, the shape maintaining property of the unevenness generated on the surface of the heat-expandable base material layer (Y1-1) is improved, and the pressure-sensitive adhesive surface of the first pressure-sensitive adhesive layer (X1) is improved. From the viewpoint of facilitating the formation of irregularities, the storage elastic modulus E ′ (t) defined by the requirement (1) of the thermally expandable base material layer (Y1-1) is preferably 1.0 × 10 ³ Pa or more. Preferably it is 1.0 × 10 ⁴ Pa or more, more preferably 1.0 × 10 ⁵ Pa or more.

The thermally expandable base material layer (Y1-1) preferably satisfies the following requirement (2), and more preferably satisfies the requirement (2) together with the requirement (1).
Requirement (2): The storage elastic modulus E ′ (23) of the thermally expandable base material layer (Y1-1) at 23 ° C. is 1.0 × 10 ⁶ Pa or more.

By using the thermally expandable base material layer (Y1-1) that satisfies the above requirement (2), it is possible to prevent displacement when the sealing object is placed on the adhesive surface of the second adhesive layer (X2). In addition, excessive sinking of the sealing object into the second pressure-sensitive adhesive layer (X2) can also be prevented.

From the above viewpoint, the storage elastic modulus E ′ (23) of the thermally expandable base material layer (Y1-1) defined by the above requirement (2) is preferably 5.0 × 10 ⁶ to 5.0 × 10 ¹² Pa. More preferably 1.0 × 10 ⁷ to 1.0 × 10 ¹² Pa, still more preferably 5.0 × 10 ⁷ to 1.0 × 10 ¹¹ Pa, and still more preferably 1.0 × 10 ⁸ to 1. 0 × 10 ¹⁰ Pa.

The heat-expandable particles contained in the heat-expandable base material layer (Y1-1) are preferably heat-expandable particles having an expansion start temperature (t) of 60 to 270 ° C.
In the present specification, the expansion start temperature (t) of the thermally expandable particles means a value measured based on the following method.
[Measurement method of expansion start temperature (t) of thermally expandable particles]
To an aluminum cup having a diameter of 6.0 mm (inner diameter: 5.65 mm) and a depth of 4.8 mm, 0.5 mg of thermally expandable particles to be measured is added, and an aluminum lid (diameter of 5.6 mm, thickness of 0.2 mm) is added from above. 1 mm) is prepared.
Using a dynamic viscoelasticity measuring device, the height of the sample is measured from the upper part of the aluminum lid to the sample with a force of 0.01 N applied by a pressurizer. Then, with a force of 0.01 N applied by the pressurizer, heating is performed from 20 ° C. to 300 ° C. at a rate of temperature increase of 10 ° C./min, and the amount of displacement of the pressurizer in the vertical direction is measured. Let the displacement start temperature be the expansion start temperature (t).

The thermally expandable particles are microencapsulated foaming agents composed of an outer shell composed of a thermoplastic resin and an encapsulated component encapsulated in the outer shell and vaporized when heated to a predetermined temperature. Preferably there is.
Examples of the thermoplastic resin constituting the outer shell of the microencapsulated foaming agent include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, and polysulfone.

Examples of the inclusion component contained in the outer shell include propane, butane, pentane, hexane, heptane, octane, nonane, decane, isobutane, isopentane, isohexane, isoheptane, isooctane, isononane, isodecane, cyclopropane, cyclobutane, cyclopentane. , Cyclohexane, cycloheptane, cyclooctane, neopentane, dodecane, isododecane, cyclotridecane, hexylcyclohexane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nanodecane, isotridecane, 4-methyldodecane, isotetradecane, isopentadecane, iso Hexadecane, 2,2,4,4,6,8,8-heptamethylnonane, isoheptadecane, isooctadecane, isonanodecane, , 6,10,14-tetramethylpentadecane, cyclotridecane, heptylcyclohexane, n-octylcyclohexane, cyclopentadecane, nonylcyclohexane, decylcyclohexane, pentadecylcyclohexane, hexadecylcyclohexane, heptadecylcyclohexane, octadecylcyclohexane, etc. .
These encapsulated components may be used alone or in combination of two or more.
The expansion start temperature (t) of the thermally expandable particles can be adjusted by appropriately selecting the type of the inclusion component.

The expandable substrate layer (Y1) is preferably formed from a resin composition (y) containing a resin and expandable particles.
In addition, you may contain the additive for base materials in the resin composition (y) in the range which does not impair the effect of this invention as needed.
Examples of the substrate additive include an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a slip agent, an antiblocking agent, and a colorant.
These base material 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 0.0001 to 20 parts by mass, more preferably 0.001 to about 100 parts by mass of the resin. 10 parts by mass.

The expandable particles contained in the resin composition (y), which is a material for forming the expandable substrate layer (Y1), are as described above, and are preferably thermally expandable particles.
The content of the expandable particles is preferably 1 to 40% by mass, more preferably 5 to 35% by mass, and further preferably 10 to 10% by mass with respect to the total amount (100% by mass) of the active ingredients of the resin composition (y). It is 30% by mass, more preferably 15 to 25% by mass.

The resin contained in the resin composition (y) that is a material for forming the expandable base material layer (Y1) 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, in the process of forming the expandable substrate layer (Y1) from the resin composition (y), the adhesive resin is a polymerizable compound. And the resulting resin becomes a non-adhesive resin, and the expandable base material layer (Y1) containing the resin may be non-adhesive.

The mass average molecular weight (Mw) of the resin contained in the resin composition (y) is preferably 1,000 to 1,000,000, more preferably 1,000 to 700,000, and still more preferably 1,000 to 500,000.
Further, when the resin is a copolymer having two or more kinds of structural units, the form of the copolymer is not particularly limited, and any of a block copolymer, a random copolymer, and a graft copolymer It may be.

The content of the resin is preferably 50 to 99% by mass, more preferably 60 to 95% by mass, and still more preferably 65 to 90% by mass with respect to the total amount (100% by mass) of the active ingredients of the resin composition (y). %, More preferably 70 to 85% by mass.

In one aspect of the present invention, the resin contained in the resin composition (y) is an acrylic urethane from the viewpoint of forming an expandable base layer (Y1) that easily forms irregularities on the surface when the expandable particles are expanded. It is preferable that 1 or more types chosen from a system resin and an olefin resin are included.
Moreover, as said acrylic urethane type resin, the following resin (U1) is preferable.
An acrylic urethane resin (U1) obtained by polymerizing a urethane prepolymer (UP) and a vinyl compound containing a (meth) acrylic acid ester.

[Acrylic urethane resin (U1)]
Examples of the urethane prepolymer (UP) serving as the main chain of the acrylic urethane resin (U1) include a reaction product of a polyol and a polyvalent isocyanate.
The urethane prepolymer (UP) is preferably obtained by further subjecting it to a chain extension reaction using a chain extender.

Examples of the polyol used as a raw material for the urethane prepolymer (UP) include alkylene type polyols, ether type polyols, ester type polyols, ester amide type polyols, ester / ether type polyols, and carbonate type polyols.
These polyols may be used independently and may use 2 or more types together.
The polyol used in one embodiment of the present invention is preferably a diol, more preferably an ester diol, an alkylene diol, and a carbonate diol, and even more preferably an ester diol and a carbonate diol.

Examples of the ester diol include alkane diols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol; ethylene glycol, propylene glycol, One or more selected from diols such as alkylene glycols such as diethylene glycol and dipropylene glycol; phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, 4,4-diphenyldicarboxylic acid, diphenylmethane-4 , 4'-dicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, het acid, maleic acid, fumaric acid, itaconic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, hexa Hydrophthalic acid, Examples thereof include condensation polymers of one or more selected from dicarboxylic acids such as hexahydroisophthalic acid, hexahydroterephthalic acid, and methylhexahydrophthalic acid, and anhydrides thereof.
Specifically, polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyhexamethylene isophthalate diol, polyneopentyl adipate diol, polyethylene propylene adipate diol, polyethylene butylene adipate diol, polybutylene hexamethylene adipate diol, Polydiethylene adipate diol, poly (polytetramethylene ether) adipate diol, poly (3-methylpentylene adipate) diol, polyethylene azelate diol, polyethylene sebacate diol, polybutylene azelate diol, polybutylene sebacate diol and polyneo Examples include pentyl terephthalate diol.

Examples of the alkylene type diol include alkane diols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol; ethylene glycol, propylene glycol, And alkylene glycols such as diethylene glycol and dipropylene glycol; polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polybutylene glycol; polyoxyalkylene glycols such as polytetramethylene glycol; and the like.

Examples of the carbonate type diol include 1,4-tetramethylene carbonate diol, 1,5-pentamethylene carbonate diol, 1,6-hexamethylene carbonate diol, 1,2-propylene carbonate diol, and 1,3-propylene carbonate diol. 2,2-dimethylpropylene carbonate diol, 1,7-heptamethylene carbonate diol, 1,8-octamethylene carbonate diol, 1,4-cyclohexane carbonate diol, and the like.

Examples of the polyvalent isocyanate used as a raw material for the urethane prepolymer (UP) include aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates.
These polyvalent isocyanates may be used alone or in combination of two or more.
These polyisocyanates may be a trimethylolpropane adduct-type modified product, a burette-type modified product reacted with water, or an isocyanurate-type modified product containing an isocyanurate ring.

Among these, the polyisocyanate used in one embodiment of the present invention is preferably diisocyanate, and 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2,4-TDI), 2,6 More preferred is at least one selected from tolylene diisocyanate (2,6-TDI), hexamethylene diisocyanate (HMDI), and alicyclic diisocyanate.

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

In one embodiment of the present invention, the urethane prepolymer (UP) serving as the main chain of the acrylic urethane resin (U1) is a reaction product of a diol and a diisocyanate, and is a straight chain having ethylenically unsaturated groups at both ends. A urethane prepolymer is preferred.
As a method for introducing an ethylenically unsaturated group into both ends of the linear urethane prepolymer, an NCO group at the end of the linear urethane prepolymer obtained by reacting a diol and a diisocyanate compound, and a hydroxyalkyl (meth) acrylate And a method of reacting with.

Examples of the hydroxyalkyl (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-hydroxy Examples thereof include butyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate.

As a vinyl compound used as the side chain of acrylic urethane type resin (U1), at least (meth) acrylic acid ester is included.
The (meth) acrylic acid ester is preferably at least one selected from alkyl (meth) acrylates and hydroxyalkyl (meth) acrylates, and more preferably used in combination with alkyl (meth) acrylates and hydroxyalkyl (meth) acrylates.

When alkyl (meth) acrylate and hydroxyalkyl (meth) acrylate are used in combination, the proportion of hydroxyalkyl (meth) acrylate to 100 parts by mass of alkyl (meth) acrylate is preferably 0.1 to 100 parts by mass, The amount is preferably 0.5 to 30 parts by mass, more 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 of the alkyl (meth) acrylate is preferably 1 to 24, more preferably 1 to 12, still more preferably 1 to 8, and still more preferably 1 to 3.

Moreover, as hydroxyalkyl (meth) acrylate, the same thing as the hydroxyalkyl (meth) acrylate used in order to introduce | transduce an ethylenically unsaturated group into the both ends of the above-mentioned linear urethane prepolymer is mentioned.

Examples of vinyl compounds other than (meth) acrylic acid esters include aromatic hydrocarbon vinyl compounds such as styrene, α-methylstyrene, and vinyl toluene; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; vinyl acetate and vinyl propionate. Polar group-containing monomers such as (meth) acrylonitrile, N-vinylpyrrolidone, (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, and meta (acrylamide).
These may be used alone or in combination of two or more.

The content of the (meth) acrylic acid ester in the vinyl compound is preferably 40 to 100% by mass, more preferably 65 to 100% by mass, and still more preferably based on the total amount (100% by mass) of the vinyl compound. It is 80 to 100% by mass, more preferably 90 to 100% by mass.

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

In the acrylic urethane resin (U1) used in one embodiment of the present invention, the content ratio of the structural unit (u11) derived from the urethane prepolymer (UP) and the structural unit (u12) derived from the vinyl compound [(u11 ) / (U12)] is preferably 10/90 to 80/20, more preferably 20/80 to 70/30, still more preferably 30/70 to 60/40, and still more preferably 35 by mass ratio. / 65 to 55/45.

[Olefin resin]
Examples of the olefin resin suitable as the resin contained in the resin composition (y) include a polymer having at least a structural unit derived from an olefin monomer.
The olefin monomer is preferably an α-olefin having 2 to 8 carbon atoms, and specifically includes ethylene, propylene, butylene, isobutylene, 1-hexene and the like.
Among these, ethylene and propylene are preferable.

Specific olefinic resins, for example, ultra low density polyethylene (VLDPE, density: 880 kg / ^{m 3} or more 910 kg / ^m less than ^3), low density polyethylene (LDPE, density: 910 kg / ^{m 3} or more 915 kg / ^m less than ³ ), Medium density polyethylene (MDPE, density: 915 kg / m ³ or more and less than 942 kg / m ³ ), high density polyethylene (HDPE, density: 942 kg / m ³ or more), linear low density polyethylene, etc .; polypropylene resin (PP); polybutene resin (PB); ethylene-propylene copolymer; olefin elastomer (TPO); ethylene-vinyl acetate copolymer (EVA); ethylene-propylene- (5-ethylidene-2-norbornene), etc. Olefin terpolymers; and the like.

In one embodiment of the present invention, the olefin resin may be a modified olefin resin further modified by one or more selected from acid modification, hydroxyl group modification, and acrylic modification.

For example, as an acid-modified olefin resin obtained by subjecting an olefin resin to acid modification, a modified polymer obtained by graft polymerization of the above-mentioned unmodified olefin resin with an unsaturated carboxylic acid or its anhydride. Is mentioned.
Examples of the unsaturated carboxylic acid or its anhydride include maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, tetrahydrophthalic acid, aconitic acid, (meth) acrylic acid, maleic anhydride, itaconic anhydride. , Glutaconic anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride, and the like.
In addition, unsaturated carboxylic acid or its anhydride may be used independently, and may use 2 or more types together.

As an acrylic modified olefin resin obtained by subjecting an olefin resin to acrylic modification, a modification obtained by graft polymerization of an alkyl (meth) acrylate as a side chain to the above-mentioned unmodified olefin resin as a main chain. A polymer is mentioned.
The number of carbon atoms of the alkyl group contained in the alkyl (meth) acrylate is preferably 1-20, more preferably 1-16, and still more preferably 1-12.
As said alkyl (meth) acrylate, the same thing as the compound which can be selected as a below-mentioned monomer (a1 ') is mentioned, for example.

Examples of the hydroxyl group-modified olefin resin obtained by modifying the olefin resin with a hydroxyl group include a modified polymer obtained by graft-polymerizing a hydroxyl group-containing compound to the above-mentioned unmodified olefin resin as the main chain.
Examples of the hydroxyl group-containing compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-hydroxybutyl. Examples include hydroxyalkyl (meth) acrylates such as (meth) acrylate and 4-hydroxybutyl (meth) acrylate; unsaturated alcohols such as vinyl alcohol and allyl alcohol.

(Resin other than acrylic urethane resin and olefin resin)
In one embodiment of the present invention, the resin composition (y) may contain a resin other than the acrylic urethane-based resin and the olefin-based resin as long as the effects of the present invention are not impaired.
Examples of such resins include vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer; polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate. Polyester resin such as phthalate; polystyrene; acrylonitrile-butadiene-styrene copolymer; cellulose triacetate; polycarbonate; polyurethane not applicable to acrylic urethane resin; polymethylpentene; polysulfone; polyetheretherketone; polyethersulfone; Sulfides; Polyimide resins such as polyetherimide and polyimide; Polyamide resins; Acrylic resins; Fluorine resins and the like.

However, from the viewpoint of making the expandable base material layer (Y1) that easily forms irregularities on the surface when the expandable particles are expanded, the resin composition (y) contains a resin other than the acrylic urethane resin and the olefin resin. A smaller ratio is preferable.
The content ratio of the resin other than the acrylic urethane-based resin and the olefin-based resin is preferably less than 30 parts by weight, more preferably 20 parts by weight with respect to 100 parts by weight of the total amount of the resin contained in the resin composition (y). Less than, more preferably less than 10 parts by weight, still more preferably less than 5 parts by weight, and even more preferably less than 1 part by weight.

[Solvent-free resin composition (y1)]
As an aspect of the resin composition (y), a solvent comprising an oligomer having an ethylenically unsaturated group having a mass average molecular weight (Mw) of 50000 or less, an energy ray polymerizable monomer, and the above-mentioned expandable particles, And a solvent-free resin composition (y1) that does not contain the above.
In the solventless resin composition (y1), no solvent is blended, but the energy beam polymerizable monomer contributes to the improvement of the plasticity of the oligomer.
By irradiating the coating film formed from the solventless resin composition (y1) with energy rays, an inflatable substrate layer (Y1) that easily forms irregularities on the surface when the expandable particles expand is formed. In particular, it is easy to form the heat-expandable base material layer (Y1-1) that satisfies the above requirements (1) and (2).

In addition, the type, shape, and blending amount (content) of the expandable particles blended in the solventless resin composition (y1) are the same as those of the resin composition (y) and are as described above.

The mass average molecular weight (Mw) of the oligomer contained in the solventless resin composition (y1) is 50000 or less, preferably 1000 to 50000, more preferably 2000 to 40000, and still more preferably 3000 to 35000. More preferably, it is 4000-30000.

Moreover, as said oligomer, what is necessary is just to have an ethylenically unsaturated group whose mass mean molecular weight is 50000 or less among resin contained in the above-mentioned resin composition (y), but the above-mentioned urethane prepolymer (UP Is preferred.
As the oligomer, a modified olefin resin having an ethylenically unsaturated group can also be used.

The total content of the oligomer and the energy beam polymerizable monomer in the solventless resin composition (y1) is preferably from 50 to the total amount (100% by mass) of the solventless resin composition (y1). It is 99% by mass, more preferably 60 to 95% by mass, still more preferably 65 to 90% by mass, and still more preferably 70 to 85% by mass.

Examples of the energy ray polymerizable monomer include isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxy (meth) acrylate, cyclohexyl (meth) acrylate, adamantane ( Alicyclic polymerizable compounds such as (meth) acrylate and tricyclodecane acrylate; Aromatic polymerizable compounds such as phenylhydroxypropyl acrylate, benzyl acrylate and phenol ethylene oxide modified acrylate; Tetrahydrofurfuryl (meth) acrylate, morpholine acrylate, N- And heterocyclic polymerizable compounds such as vinylpyrrolidone and N-vinylcaprolactam.
These energy beam polymerizable monomers may be used independently and may use 2 or more types together.

The blending ratio of the oligomer and the energy beam polymerizable monomer (the oligomer / energy beam polymerizable monomer) is preferably 20/80 to 90/10, more preferably 30/70 to 85/15, still more preferably 35/65. ~ 80/20.

In one embodiment of the present invention, it is preferable that the solventless resin composition (y1) further comprises a photopolymerization initiator.
By containing the photopolymerization initiator, the curing reaction can be sufficiently advanced even by irradiation with energy rays having relatively low energy.

Examples of the photopolymerization initiator include 1-hydroxy-cyclohexyl-phenyl-ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzyl phenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyrol. Nitrile, dibenzyl, diacetyl, 8-chloranthraquinone and the like can be mentioned.
These photoinitiators may be used independently and may use 2 or more types together.

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 with respect to the total amount (100 parts by mass) of the oligomer and the energy ray polymerizable monomer. The amount is preferably 0.02 to 3 parts by mass.

<Non-expandable base material layer (Y2)>
Examples of the material for forming the non-intumescent base material layer (Y2) constituting the base material (Y) include paper materials, resins, metals, and the like.
Examples of the paper material include thin paper, medium quality paper, high quality paper, impregnated paper, coated paper, art paper, sulfuric acid paper, glassine paper, and the like.
Examples of the resin include polyolefin resins such as polyethylene and polypropylene; vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, and ethylene-vinyl alcohol copolymer; polyethylene terephthalate, poly Polyester resins such as butylene terephthalate and polyethylene naphthalate; polystyrene; acrylonitrile-butadiene-styrene copolymer; cellulose triacetate; polycarbonate; urethane resin such as polyurethane and acrylic-modified polyurethane; polymethylpentene; polysulfone; polyether ether ketone; Polyethersulfone; Polyphenylene sulfide; Polyimide resin such as polyetherimide and polyimide; Polyamide resin; Acrylic resin; Tsu Motokei resin, and the like.
Examples of the metal include aluminum, tin, chromium, and titanium.

These forming materials may be composed of one kind or in combination of two or more kinds.
As a non-intumescent base material layer (Y2) using two or more kinds of forming materials in combination, a paper film is laminated with a thermoplastic resin such as polyethylene, or a metal film is formed on the surface of a resin film or sheet containing a resin. And the like.
As a method for forming the metal layer, for example, a method of depositing the metal by a PVD method such as vacuum deposition, sputtering, or ion plating, or a metal foil made of the metal is attached using a general adhesive. And the like.

From the viewpoint of improving interlayer adhesion between the non-expandable base layer (Y2) and other layers to be laminated, when the non-expandable base layer (Y2) contains a resin, the non-expandable base layer ( Similarly to the expandable base material layer (Y1) described above, the surface of Y2) may be subjected to a surface treatment such as an oxidation method or an unevenness method, an easy adhesion treatment, or a primer treatment.

Moreover, when the non-intumescent base material layer (Y2) contains a resin, it may contain the above-mentioned base material additive that can be contained in the resin composition (y) together with the resin.

The non-intumescent substrate layer (Y2) is present at a position farther from the first pressure-sensitive adhesive layer (X1) than the above-described inflatable substrate layer (Y1), and the inflatable substrate layer (Y1) ) And the first pressure-sensitive adhesive layer (X1), there is no non-expandable base layer (Y2), and the non-expandable base layer (Y2) when the expandable particles expand. The storage elastic modulus E ′ is preferably larger than the storage elastic modulus E ′ of the expandable base material layer (Y1) when the expandable particles expand. Thus, since there is no non-expandable base material layer (Y2) between the expandable base material layer (Y1) and the first pressure-sensitive adhesive layer (X1), the expandable base material layer is expanded by the expansion of the expandable particles. The unevenness generated on the surface of (Y1) is transmitted to the first pressure-sensitive adhesive layer (X1) without interposing the non-intumescent base material layer (Y2), and on the pressure-sensitive adhesive surface of the first pressure-sensitive adhesive layer (X1). Also, unevenness is likely to occur. Further, when the expandable particles expand, the storage elastic modulus E ′ of the non-expandable base material layer (Y2) is larger than the storage elastic modulus E ′ of the expandable base material layer (Y1). During expansion, the surface of the expandable substrate layer (Y1) on the non-expandable substrate layer (Y2) side is prevented from being uneven, and as a result, the first of the expandable substrate layer (Y1). Unevenness is likely to occur on the surface on the pressure-sensitive adhesive layer (X1) side, and therefore unevenness is also likely to occur on the adhesive surface of the first pressure-sensitive adhesive layer (X1).
The storage elastic modulus E ′ of the non-expandable base material layer (Y2) when the expandable particles are expanded is as described above from the viewpoint of easily forming irregularities on the adhesive surface of the first adhesive layer (X1). Preferably, the pressure is 1.0 MPa or more. Also, from the viewpoint of ease of pasting and peeling operations, from the viewpoint of causing irregularities on the adhesive surface of the second pressure-sensitive adhesive layer (X2), or handling in a roll shape. From the viewpoint of easiness, it is preferably 1.0 × 10 ³ MPa or less. From this viewpoint, the storage elastic modulus E ′ of the non-expandable base material layer (Y2) when the expandable particles expand is preferably 1.0 to 5.0 × 10 ² MPa, more preferably 1.0. × 10 ¹ to 1.0 × 10 ² MPa, more preferably 5.0 × 10 ¹ to 1.0 × 10 ³ MPa.
In addition, from the viewpoints described above and from the viewpoint of preventing misalignment when the semiconductor wafer is attached to the adhesive surface of the second adhesive layer (X2), the storage elastic modulus of the non-expandable base material layer (Y2) at 23 ° C. E ′ (23) is preferably 5.0 × 10 ¹ to 5.0 × 10 ⁴ MPa, more preferably 1.0 × 10 ² to 1.0 × 10 ⁴ MPa, and even more preferably 5.0 × 10. ² to 5.0 × 10 ³ MPa. A non-expandable base material layer (Y2) is a non-expandable layer judged based on the above-mentioned method.
Therefore, the volume change rate (%) of the non-expandable base material layer (Y2) calculated from the above formula is less than 5% by volume, preferably less than 2% by volume, more preferably less than 1% by volume. More preferably, it is less than 0.1 volume%, More preferably, it is less than 0.01 volume%.

Moreover, as long as the volume change rate is the said range, a non-expandable base material layer (Y2) may contain a thermally expansible particle. For example, by selecting a resin contained in the non-expandable base material layer (Y2), it is possible to adjust the volume change rate to the above range even if thermally expandable particles are included.
However, the smaller the content of the heat-expandable particles in the non-expandable base material layer (Y2), the better.
The specific content of the heat-expandable particles is usually less than 3% by mass, preferably less than 1% by mass, and more preferably relative to the total mass (100% by mass) of the non-expandable base material layer (Y2). It is less than 0.1% by mass, more preferably less than 0.01% by mass, and still more preferably less than 0.001% by mass.

<First pressure-sensitive adhesive layer (X1), second pressure-sensitive adhesive layer (X2)>
The pressure-sensitive adhesive sheet used in one embodiment of the present invention has a first pressure-sensitive adhesive layer (X1) and a second pressure-sensitive adhesive layer (X2), which are non-intumescent pressure-sensitive adhesive layers.
In the production method of the present invention, the pressure-sensitive adhesive surface of the first pressure-sensitive adhesive layer (X1) is affixed to a hard support, and a sealing object is placed on the pressure-sensitive adhesive surface of the second pressure-sensitive adhesive layer (X2). A cured encapsulant is formed.

Since the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2) are non-expandable pressure-sensitive adhesive layers, the position of the sealing target due to insufficient fixation between the sealing target and the hard support It is possible to effectively suppress adverse effects such as displacement and adhesion of the sealing resin to the exposed surface of the object to be sealed.
In addition, since the first pressure-sensitive adhesive layer (X1) is a non-intumescent pressure-sensitive adhesive layer, in addition to the above effects, in the cured sealed body with the pressure-sensitive adhesive sheet after separation from the cured support, The adhesive layer (X1) can be prevented from falling off and the like, which can contaminate various devices in the manufacturing environment.

The first pressure-sensitive adhesive layer (X1) has high adhesiveness with the hard support before expansion of the expandable particles contained in the expandable base material layer (Y1), and the sealing object is sufficient for the hard support. The property which can be fixed to is required.
From this viewpoint, the storage shear modulus G ′ (23) of the first pressure-sensitive adhesive layer (X1) at 23 ° C. is preferably 1.0 × 10 ⁸ Pa or less, more preferably 5.0 × 10 ⁷ Pa or less. More preferably, it is 1.0 × 10 ⁷ Pa or less.

On the other hand, when the expandable particles in the expandable base material layer (Y1) expand, the unevenness generated on the surface of the expandable base material layer (Y1) is also applied to the adhesive surface of the first pressure-sensitive adhesive layer (X1). Rigidity that can be formed is also required.
From this viewpoint, the storage shear modulus G ′ (23) of the first pressure-sensitive adhesive layer (X1) at 23 ° C. is preferably 1.0 × 10 ⁴ Pa or more, more preferably 5.0 × 10 ⁴ Pa or more. More preferably, it is 1.0 × 10 ⁵ Pa or more.

In addition, the second pressure-sensitive adhesive layer (X2) is required to have not only adhesion with the sealing object but also adhesion with a cured sealing body formed by sealing the sealing object with a sealing material. The Moreover, it is necessary to suppress the phenomenon that the sealing target object excessively sinks into the second pressure-sensitive adhesive layer (X2).
From these viewpoints, the storage shear modulus G ′ (23) of the second pressure-sensitive adhesive layer (X2) at 23 ° C. is preferably 1.0 × 10 ⁴ to 1.0 × 10 ⁸ Pa, more preferably 5 It is 0.0 × 10 ⁴ to 5.0 × 10 ⁷ Pa, more preferably 9.0 × 10 ⁴ to 1.0 × 10 ⁷ Pa.
In addition, in this specification, the storage shear elastic modulus G '(23) of the 1st adhesive layer (X1) and the 2nd adhesive layer (X2) means the value measured by the method as described in an Example. .

The thickness of the first pressure-sensitive adhesive layer (X1) is preferably 1 to 60 μm, more preferably 2 to 50 μm, still more preferably 3 to 40 μm, and still more preferably 5 to 30 μm.

The thickness of the second pressure-sensitive adhesive layer (X2) is preferably 1 to 60 μm, more preferably 2 to 50 μm, still more preferably 3 to 40 μm, and still more preferably 5 to 30 μm.

The first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2) can be formed from a pressure-sensitive adhesive composition (x) containing a pressure-sensitive adhesive resin.
Moreover, adhesive composition (x) may contain additives for adhesives, such as a crosslinking agent, a tackifier, a polymeric compound, a polymerization initiator, as needed.
Hereinafter, each component contained in the pressure-sensitive adhesive composition (x) will be described.

(Adhesive resin)
As the adhesive resin used in one embodiment of the present invention, any polymer may be used as long as it has adhesiveness and has a mass average molecular weight (Mw) of 10,000 or more.
The mass average molecular weight (Mw) of the adhesive resin used in one embodiment of the present invention is preferably 10,000 to 2,000,000, more preferably 20,000 to 1,500,000, and still more preferably 30,000, from the viewpoint of improving adhesive force. ~ 1 million.

Specific examples of the adhesive resin include rubber resins such as acrylic resins, urethane resins, and polyisobutylene resins, polyester resins, olefin resins, silicone resins, and polyvinyl ether resins.
These adhesive resins may be used alone or in combination of two or more.
Further, when these adhesive resins are copolymers having two or more kinds of structural units, the form of the copolymer is not particularly limited, and a block copolymer, a random copolymer, and a graft copolymer are not limited. Any of polymers may be used.

The adhesive resin used in one embodiment of the present invention may be an energy ray curable adhesive resin in which a polymerizable functional group is introduced into the side chain of the above-mentioned adhesive resin.
For example, by forming the second pressure-sensitive adhesive layer (X2) from an energy ray-curable pressure-sensitive adhesive composition containing an energy ray-curable pressure-sensitive adhesive resin, the adhesive force can be reduced by irradiating energy rays. Therefore, the obtained cured sealing body can be easily separated from the second pressure-sensitive adhesive layer (X2).
Examples of the polymerizable functional group include a (meth) acryloyl group and a vinyl group.
Examples of energy rays include ultraviolet rays and electron beams, but ultraviolet rays are preferred.
In addition, as a forming material of the adhesive layer which can irradiate an energy ray and can reduce adhesive force, the energy ray hardening-type adhesive composition containing the monomer or oligomer which has a polymerizable functional group may be sufficient.

These energy ray curable pressure-sensitive adhesive compositions preferably further contain a photopolymerization initiator.
By containing the photopolymerization initiator, the curing reaction can be sufficiently advanced even by irradiation with energy rays having relatively low energy.
As a photoinitiator, the same thing as what is mix | blended with the above-mentioned solvent-free resin composition (y1) is mentioned.
The content of the photopolymerization initiator is preferably 0.01 to 10 parts by mass, more preferably 100 parts by mass of the energy ray-curable adhesive resin or 100 parts by mass of the monomer or oligomer having a polymerizable functional group. The amount is 0.03 to 5 parts by mass, more preferably 0.05 to 2 parts by mass.

In one embodiment of the present invention, the adhesive resin preferably contains an acrylic resin from the viewpoint of developing an excellent adhesive force. In particular, by forming the first pressure-sensitive adhesive layer (X1) from a pressure-sensitive adhesive composition containing an acrylic resin, it is possible to easily form irregularities on the surface of the first pressure-sensitive adhesive layer.

The content of the acrylic resin in the adhesive resin is preferably 30 to 100% by mass, more preferably 50%, based on the total amount (100% by mass) of the adhesive resin contained in the adhesive composition (x). To 100% by mass, more preferably 70 to 100% by mass, and still more preferably 85 to 100% by mass.

The content of the adhesive resin is preferably 35 to 100% by mass, more preferably 50 to 100% by mass, still more preferably relative to the total amount (100% by mass) of the active ingredients of the adhesive composition (x). It is 60 to 98% by mass, more preferably 70 to 95% by mass.

(Crosslinking agent)
In one aspect of the present invention, when the pressure-sensitive adhesive composition (x) contains a pressure-sensitive adhesive resin having a functional group, the pressure-sensitive adhesive composition (x) preferably further contains a crosslinking agent.
The said crosslinking agent reacts with the adhesive resin which has a functional group, and bridge | crosslinks adhesive resins by using the said functional group as a crosslinking origin.

Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, and a metal chelate crosslinking agent.
These crosslinking agents may be used independently and may use 2 or more types together.
Among these crosslinking agents, an isocyanate-based crosslinking agent is preferable from the viewpoints of increasing cohesive force and improving adhesive force and availability.

The content of the crosslinking agent is appropriately adjusted depending on the number of functional groups that the adhesive resin has, but is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the adhesive resin having a functional group, The amount is more preferably 0.03 to 7 parts by mass, still more preferably 0.05 to 5 parts by mass.

(Tackifier)
In one embodiment of the present invention, the pressure-sensitive adhesive composition (x) may further contain a tackifier from the viewpoint of further improving the adhesive strength.
In the present specification, the “tackifier” is a component that assists in improving the adhesive strength of the above-mentioned adhesive resin, and refers to an oligomer having a mass average molecular weight (Mw) of less than 10,000. It is distinguished from a functional resin.
The mass average molecular weight (Mw) of the tackifier is preferably 400 to 10000, more preferably 500 to 8000, and still more preferably 800 to 5000.

Examples of the tackifier are obtained by copolymerizing C5 fractions such as rosin resin, terpene resin, styrene resin, pentene, isoprene, piperine, 1,3-pentadiene generated by thermal decomposition of petroleum naphtha. And C9 petroleum resin obtained by copolymerizing C9 fractions such as indene generated by thermal decomposition of petroleum naphtha and vinyltoluene, and hydrogenated resins obtained by hydrogenating these.

The softening point of the tackifier is preferably 60 to 170 ° C, more preferably 65 to 160 ° C, and still more preferably 70 to 150 ° C.
In the present specification, the “softening point” of the tackifier means a value measured according to JIS K2531.
A tackifier may be used independently and may use together 2 or more types from which a softening point and a structure differ.
And when using 2 or more types of several tackifier, it is preferable that the weighted average of the softening point of these several tackifiers belongs to the said range.

The content of the tackifier is preferably 0.01 to 65% by mass, more preferably 0.1 to 50% by mass, based on the total amount (100% by mass) of the active ingredients of the adhesive composition (x). More preferably, it is 1 to 40% by mass, and still more preferably 2 to 30% by mass.

(Adhesive additive)
In one embodiment of the present invention, the pressure-sensitive adhesive composition (x) contains an additive for pressure-sensitive adhesives used for general pressure-sensitive adhesives in addition to the above-mentioned additives, as long as the effects of the present invention are not impaired. You may do it.
Examples of such an adhesive additive include antioxidants, softeners (plasticizers), rust inhibitors, pigments, dyes, retarders, reaction accelerators (catalysts), ultraviolet absorbers, antistatic agents, and the like. Is mentioned.
These pressure-sensitive adhesive additives may be used alone or in combination of two or more.

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

The first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2) are both non-expandable pressure-sensitive adhesive layers, but preferably do not substantially contain expandable particles.
Here, “substantially does not contain expandable particles” means that the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2) do not contain expandable particles for a specific purpose. It means that. Therefore, it does not exclude the aspect in which expandable particles are mixed as impurities in the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2).
Specifically, as the content of the expandable particles, the total amount of active ingredients (100) of the pressure-sensitive adhesive composition (x) which is a material for forming the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2). % By mass) or the total mass (100% by mass) of the first adhesive layer (X1) and the second adhesive layer (X2), preferably less than 1% by mass, more preferably 0.1% by mass. Less than, more preferably less than 0.01% by mass, and still more preferably less than 0.001% by mass.

<Release material>
In the pressure-sensitive adhesive sheet used in one embodiment of the present invention, a release material may be further laminated on the pressure-sensitive adhesive surfaces of the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2).
As the release material, a release sheet that has been subjected to a double-sided release process, a release sheet that has been subjected to a single-sided release process, or the like is used, and examples include a release material coated on a release material.

Examples of the base material for the release material include papers such as high-quality paper, glassine paper, and kraft paper; polyester resin films such as polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin; and olefins such as polypropylene resin and polyethylene resin. A plastic film such as a resin film;

Examples of the release agent include silicone-based resins, olefin-based resins, isoprene-based resins, rubber-based elastomers such as butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, and fluorine-based resins.

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

[Each process of the manufacturing method of the hardening sealing body of the present invention]
The production method of the present invention is a method for producing a cured encapsulant using the above-mentioned pressure-sensitive adhesive sheet, and includes the following steps (1) to (3).
-Process (1): The process of sticking the adhesion surface of a 1st adhesive layer (X1) on a hard support body, and mounting a sealing target object on a part of adhesion surface of a 2nd adhesive layer (X2). .
Step (2): The sealing object and the adhesive surface of the second pressure-sensitive adhesive layer (X2) at least in the periphery of the sealing object are covered with a sealing material, and the sealing material is cured. And the process of obtaining the hardening sealing body formed by sealing the said sealing target object with the said sealing material.
Step (3): The expandable particles are expanded and the hard support and the first pressure-sensitive adhesive layer (X1) are stacked while the cured sealing body is laminated on the second pressure-sensitive adhesive layer (X2). Separating at the interface P.

FIG. 2 is a schematic cross-sectional view in steps (1) to (3) of the method for producing a cured encapsulated body of the present invention.
Hereinafter, steps (1) to (3) will be described with reference to FIG. 2 as appropriate.

<Step (1)>
Fig.2 (a) is a cross-sectional schematic diagram in process (1) at the time of using the adhesive sheet 1a shown to Fig.1 (a).
In step (1), as shown in FIG. 2 (a), the adhesive surface of the first adhesive layer (X1) of the adhesive sheet 1a is affixed to the hard support 50, and the adhesive of the second adhesive layer (X2). In this step, the sealing object 60 is placed on a part of the surface.
In this step, it is preferable to place the exposed surface 61 of the sealing object 60 in contact with a part of the adhesive surface of the second pressure-sensitive adhesive layer (X2).
Further, the number of sealing objects to be placed on a part of the adhesive surface of the second pressure-sensitive adhesive layer (X2) may be one or plural as shown in FIG. . When mounting a plurality of objects to be sealed, it is preferable to place the objects so that the interval between adjacent objects to be sealed is constant.

In addition, in FIG. 2, although the aspect using the adhesive sheet 1a shown to Fig.1 (a) is shown, also when using the adhesive sheet which has another structure, a hard support body, an adhesive sheet, And the semiconductor chip are stacked or placed in this order, the adhesive surface of the first adhesive layer (X1) of the adhesive sheet is attached to the hard support, and the adhesive surface of the second adhesive layer (X2) is sealed. It is preferable to affix to the exposed surface of the object.

In addition, it is preferable to perform a process (1) in the environment where an expandable particle does not expand | swell.
For example, when thermally expandable particles are used as the expandable particles, the step (1) may be performed under a temperature condition that is lower than the expansion start temperature (t) of the thermally expandable particles. Is preferably performed in an environment of 0 to 80 ° C. (when the expansion start temperature (t) is 60 to 80 ° C., in an environment lower than the expansion start temperature (t)).

The hard support is preferably affixed to the entire pressure-sensitive adhesive surface of the first pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet. Therefore, the hard support is preferably plate-shaped.
Moreover, it is preferable that the area of the surface of the hard support stuck with the 1st adhesive layer (X1) is more than the area of the adhesive surface of the 1st adhesive layer (X1), as shown in FIG.

Examples of the material constituting the hard support include, for example, metal materials such as SUS; non-metallic inorganic materials such as glass and silicon wafers; epoxy resins, ABS resins, acrylic resins, engineering plastics, super engineering plastics, polyimide resins, polyamideimides Examples thereof include resin materials such as resins; composite materials such as glass epoxy resins, and among these, SUS, glass, and silicon wafers are preferable.
Examples of engineering plastics include nylon, polycarbonate (PC), and polyethylene terephthalate (PET).
Examples of super engineering plastics include polyphenylene sulfide (PPS), polyether sulfone (PES), and polyether ether ketone (PEEK).

The thickness of the hard support is preferably 20 μm or more and 50 mm or less, and more preferably 60 μm or more and 20 mm or less.

As the Young's modulus of the hard support, the semiconductor chip is sufficiently fixed to the hard support, and the occurrence of positional deviation of the sealing object or the sealing of the sealing object to the exposed surface in the step (2) From the viewpoint of effectively suppressing adverse effects such as resin adhesion, it is preferably 1.0 GPa or more, more preferably 5.0 GPa or more, still more preferably 10 GPa or more, and even more preferably 20 GPa or more.
In the present specification, the Young's modulus of the hard support is a value measured at room temperature (25 ° C.) in accordance with the static Young's modulus test method of JIS Z2280: 1993.

On the other hand, examples of the sealing object placed on a part of the adhesive surface of the second adhesive layer (X2) include, for example, a semiconductor chip, a semiconductor wafer, a compound semiconductor, a semiconductor package, an electronic component, a sapphire substrate, a display, Panel substrates and the like can be mentioned.
In addition, the sealing target object mounted may be comprised from the same kind, and may be comprised from 2 or more types of different things.

The exposed surface of these objects to be sealed refers to the surface that is in contact with the adhesive surface of the second pressure-sensitive adhesive layer (X2) and is not covered with the sealing material, and specifically corresponds to the circuit surface.
In the manufacturing method of the present invention, since the sealing object is sufficiently fixed to the hard support, the sealing resin on the exposed surface of the sealing object is sealed during the sealing step of step (2). It is possible to effectively suppress harmful effects such as adhesion. For example, if the sealing resin adheres to the circuit surface, the circuit wiring is disconnected, which causes a decrease in yield. However, according to the manufacturing method of the present invention, such an adverse effect can be suppressed.

Examples of the method for placing the sealing object include a pick-and-place method using an apparatus such as a flip chip bonder and a die bonder, and a batch transfer method using a transfer device.
Further, the layout, the number of arrangements, and the like of the objects to be sealed may be appropriately determined according to the target package form, the number of production, and the like.

The cured sealing body manufactured by the manufacturing method of the present invention is preferably used for FOWLP. Therefore, it is preferable that the sealing object is a semiconductor chip.
A conventionally known semiconductor chip can be used, and a semiconductor chip on which an integrated circuit composed of circuit elements such as a transistor, a resistor, and a capacitor is formed can be used.
A semiconductor chip used in one embodiment of the present invention is a semiconductor wafer in which a circuit is formed on one surface of a substrate formed of silicon, SiC (silicon carbide), gallium, arsenic, or the like by an etching method, a lift-off method, or the like. Can be obtained.
In addition, as a method of obtaining a semiconductor chip from a semiconductor wafer, a stealth dicing method, a tip dicing method, or a method other than these methods may be used.

The exposed surface of the semiconductor chip placed on the adhesive surface of the second adhesive layer (X2) is preferably a circuit surface on which a circuit is formed.
By placing the circuit surface of the semiconductor chip on the adhesive surface of the second pressure-sensitive adhesive layer (X2), the circuit surface of the semiconductor chip can be protected in the process of step (2).
On the other hand, the surface opposite to the circuit surface of the semiconductor chip (hereinafter also referred to as “back surface”) is the side that is covered with a sealing material in the next step, and normally, no circuit or electrode is formed. It is a flat surface.

Here, as in FOWLP, FOPLP, etc., a region larger than the chip size is covered with a sealing material, and a rewiring layer is formed not only on the circuit surface of the semiconductor chip but also on the surface region of the sealing material. It is preferable to be applied to a package.
Therefore, the semiconductor chip is placed on a part of the adhesive surface of the second pressure-sensitive adhesive layer (X2), and the plurality of semiconductor chips are arranged in a state of being spaced apart at a certain interval. It is preferable that the plurality of semiconductor chips be mounted on the adhesive surface in a state of being arranged in a matrix of a plurality of rows and a plurality of columns with a certain interval.
The interval between the semiconductor chips may be determined as appropriate according to the form of the target package.

<Step (2)>
In step (2), as shown in FIG. 2B, the sealing object 60 and the adhesive surface of the second adhesive layer (X2) at least in the peripheral part of the sealing object 60 are sealed. The sealing material 70 is covered (hereinafter also referred to as “coating treatment”), the sealing material 70 is cured (hereinafter also referred to as “curing treatment”), and the sealing object 60 is sealed with the sealing material 70. This is a step of obtaining a cured sealing body 80 that is stopped.

In the covering process of the step (2), when a plurality of sealing objects are placed while covering the entire exposed surface of the sealing object with the sealing material, the sealing material is It is preferable to cover the gap between the objects to be sealed.
Moreover, as shown in FIG.2 (b), you may coat | cover with the sealing material 70 so that all the adhesion surfaces of the sealing target object 60 and the 2nd adhesive layer (X2) may be covered.

The sealing material has a function of protecting the object to be sealed and its accompanying elements from the external environment.
The sealing material used in the production method of the present invention is preferably a thermosetting sealing material containing a thermosetting resin from the viewpoint of handleability.
The sealing material may be a solid such as a granule, a pellet, or a film at room temperature, or may be a liquid in the form of a composition. A sealing resin film that is a stopper is preferred.

As a coating method, it can select and apply suitably from the methods applied to the conventional sealing process according to the kind of sealing material.
Specific examples of the coating method include a roll laminating method, a vacuum pressing method, a vacuum laminating method, a spin coating method, a die coating method, a transfer molding method, and a compression molding method.

The coating treatment and the curing treatment in the step (2) are preferably performed in an environment where the expandable particles do not expand.
For example, when thermally expandable particles are used as the expandable particles, the step (2) may be performed under a temperature condition that is lower than the expansion start temperature (t) of the thermally expandable particles. Is preferably performed in an environment of 0 to 80 ° C. (when the expansion start temperature (t) is 60 to 80 ° C., in an environment lower than the expansion start temperature (t)).

And after performing a coating process, the sealing material is hardened and the hardening sealing body formed by sealing a sealing target object with a sealing material is obtained.
In addition, the coating process and the thermosetting process may be performed separately. However, when the sealing material is heated in the coating process, the sealing material is thermoset as it is by the heating, and the coating process and the heat curing process are performed. You may implement a hardening process simultaneously.

<Step (3)>
In the step (3), the expandable particles are expanded, and the cured sealing body is laminated on the second pressure-sensitive adhesive layer (X2), with the hard support and the first pressure-sensitive adhesive layer (X1). This is a process of separation at the interface P.
FIG. 2C shows a state where the expandable particles in the expandable base material layer (Y1) are expanded and separated at the interface P between the hard support 50 and the first pressure-sensitive adhesive layer (X1). .

In this step, the method for expanding the expandable particles is appropriately selected according to the type of the expandable particles.
For example, when heat-expandable particles are used as the expandable particles, heat treatment is performed at a temperature equal to or higher than the expansion start temperature (t) of the heat-expandable particles to expand the heat-expandable particles.
At this time, the “temperature higher than the expansion start temperature (t)” is preferably “expansion start temperature (t) + 10 ° C.” or higher and “expansion start temperature (t) + 60 ° C.” or lower. It is more preferable that the temperature is not less than “temperature (t) + 15 ° C.” and not more than “expansion start temperature (t) + 40 ° C.”.

In the production method of the present invention, the first pressure-sensitive adhesive layer adhered to the hard support by the expansion of the expandable particles using the pressure-sensitive adhesive sheet having the expandable base material layer (Y1) containing the expandable particles. By forming irregularities on the adhesive surface of (X1), it is adjusted so that it can be separated at the interface P between the hard support and the first adhesive layer (X1).
Therefore, the contamination of the hard support, such that a part of the first pressure-sensitive adhesive layer (X1) remains on the surface of the hard support after the separation, can be eliminated, and the washing process of the hard support can be omitted. Can be improved.

Further, in this step, when the expandable particles are expanded, it is preferable not to separate between the layers of the pressure-sensitive adhesive sheet.
That is, as shown in FIG. 2 (c), it is preferable to remove all the layers of the pressure-sensitive adhesive sheet without remaining on the surface of the hard support 50 by the step (3).
Usually, the hard support after separating the pressure-sensitive adhesive sheet is generally subjected to the same process by attaching a new pressure-sensitive adhesive sheet again. At this time, if a part of the pressure-sensitive adhesive sheet remains on the surface of the hard support due to separation between the layers constituting the pressure-sensitive adhesive sheet, a step for removing this layer is required.

On the other hand, in this step, when the expandable particles are expanded, the above problems are not caused by not separating between the layers constituting the pressure-sensitive adhesive sheet, and the productivity of manufacturing the cured sealed body is further improved. Can be made.
In addition, as described above, in the cured sealed body with the pressure-sensitive adhesive sheet after separation, the first pressure-sensitive adhesive layer (X1) located in the outermost layer of the pressure-sensitive adhesive sheet is a non-intumescent pressure-sensitive adhesive layer. Defects such as the pressure-sensitive adhesive layer (X1) dropping off hardly occur. From this point of view, the problem of contamination in the manufacturing environment is suppressed, which is a factor that can improve productivity.

In addition, after removing the adhesive sheet, the resulting cured sealing body effectively suppresses adverse effects such as occurrence of displacement of the sealing object and adhesion of the sealing resin to the exposed surface of the sealing object. Has been.
Therefore, according to the manufacturing method of this invention, the yield in manufacture of such a hardening sealing body can be improved.

The obtained cured encapsulant is thereafter subjected to a step of grinding the encapsulant of the cured encapsulant until the surface of the object to be sealed is exposed, a step of rewiring the circuit surface, an external electrode You may pass through the process of forming a pad and connecting an external electrode pad and an external terminal electrode.
Further, after the external terminal electrode is connected to the cured sealing body, it can be separated into individual pieces to manufacture a semiconductor device.

The present invention will be specifically described with reference to the following examples, but the present invention is not limited to the following examples. In addition, the physical-property value in the following manufacture examples and Examples is a value measured by the following method.

<Mass average molecular weight (Mw)>
Using a gel permeation chromatograph (product name “HLC-8020” manufactured by Tosoh Corporation), the measurement was performed under the following conditions, and the value measured in terms of standard polystyrene was used.
(Measurement condition)
Column: "TSK guard column HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL", and "TSK gel G1000HXL" (both manufactured by Tosoh Corporation) Column temperature: 40 ° C
・ Developing solvent: Tetrahydrofuran ・ Flow rate: 1.0 mL / min

<Measurement of average particle diameter of expandable particles, 90% particle diameter (D ₉₀ )>
The particle distribution of the target expandable particles was measured using a laser diffraction particle size distribution measuring apparatus (for example, product name “Mastersizer 3000” manufactured by Malvern).
Then, from the particle distribution, the particle size corresponding to 50% of the cumulative volume frequency calculated from the smaller particle size of the expandable particles is defined as “average particle size”, and the particle size corresponding to 90% of the cumulative volume frequency. “90% particle size (D ₉₀ )”.

<Measurement of thickness of each layer>
It was measured using a constant pressure thickness measuring instrument (model number: “PG-02J”, standard: JIS K6783, Z1702, Z1709 compliant) manufactured by Teclock Co., Ltd.

<Storage elastic modulus E ′ of thermally expandable base material layer (Y1)>
The formed heat-expandable base material layer (Y1) was 5 mm long × 30 mm wide × 200 μm thick, and the sample from which the release material was removed was used as a test sample.
Using a dynamic viscoelasticity measuring apparatus (TA Instruments, product name “DMAQ800”), a test start temperature of 0 ° C., a test end temperature of 300 ° C., a temperature increase rate of 3 ° C./min, a frequency of 1 Hz, and an amplitude of 20 μm Under the conditions, the storage elastic modulus E ′ of the test sample at a predetermined temperature was measured.

<Storage shear modulus G ′ of the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2)>
A sample prepared by cutting the formed first pressure-sensitive adhesive layer (X1) and second pressure-sensitive adhesive layer (X2) into a circle having a diameter of 8 mm, removing the release material, and superposing them to obtain a thickness of 3 mm It was.
Using a viscoelasticity measuring device (manufactured by Anton Paar, device name “MCR300”), a torsional shear method under conditions of a test start temperature of 0 ° C., a test end temperature of 300 ° C., a heating rate of 3 ° C./min, and a frequency of 1 Hz Was used to measure the storage shear modulus G ′ of the test sample at a given temperature.

<Probe tack value>
A base material layer to be measured was cut into a square with a side of 10 mm, and then allowed to stand for 24 hours in an environment of 23 ° C. and 50% RH (relative humidity) was used as a test sample.
Using a tacking tester (manufactured by Nippon Special Instrument Co., Ltd., product name “NTS-4800”) in an environment of 23 ° C. and 50% RH (relative humidity), the probe tack value on the surface of the test sample was measured according to JIS. It measured based on Z0237: 1991.
Specifically, a stainless steel probe having a diameter of 5 mm is brought into contact with the surface of the test sample at a contact load of 0.98 N / cm ² for 1 second, and then the probe is moved at a speed of 10 mm / sec. The force required to separate from the surface was measured, and the obtained value was used as the probe tack value of the test sample.

<Measurement of adhesive strength of second adhesive layer (X2)>
On the adhesive surface of the second adhesive layer (X2) formed on the release film, a 50 μm thick PET film (product name “Cosmo Shine A4100” manufactured by Toyobo Co., Ltd.) is laminated, did.
Then, the release film was removed, and the exposed adhesive surface of the second adhesive layer (X2) was attached to a stainless steel plate (SUS304 360 polishing) as an adherend, and 23 ° C., 50% RH (relative humidity). ) Under the same environment, the adhesive strength at 23 ° C. was measured at a pulling rate of 300 mm / min by the 180 ° peeling method in accordance with JIS Z0237: 2000.

<Young's modulus of hard support>
The measurement was performed at room temperature (25 ° C.) in accordance with the static Young's modulus test method of JIS Z2280: 1993.

Production Example 1 (Synthesis of acrylic urethane resin)
(1) Synthesis of urethane prepolymer)
In a reaction vessel under a nitrogen atmosphere, with respect to 100 parts by mass (solid content ratio) of polycarbonate diol having a weight average molecular weight of 1,000, isophorone diisocyanate has an equivalent ratio of hydroxyl group of polycarbonate diol and isocyanate group of isophorone diisocyanate of 1. / 1, 160 parts by mass of toluene was further added, and the mixture was allowed to react at 80 ° C. for 6 hours or more while stirring under a nitrogen atmosphere until the isocyanate group concentration reached the theoretical amount.
Subsequently, a solution obtained by diluting 1.44 parts by mass (solid content ratio) of 2-hydroxyethyl methacrylate (2-HEMA) in 30 parts by mass of toluene is added, and further at 80 ° C. until the isocyanate groups at both ends disappear. The reaction was performed for 6 hours to obtain a urethane prepolymer having a mass average molecular weight of 29,000.

(2) Synthesis of acrylic urethane-based resin In a reaction vessel under a nitrogen atmosphere, 100 parts by mass of urethane prepolymer obtained in Production Example 1 (solid content ratio), 117 parts by mass of methyl methacrylate (MMA) (solid content ratio), 2-hydroxyethyl methacrylate (2-HEMA) 5.1 parts by mass (solid content ratio), 1-thioglycerol 1.1 parts by mass (solid content ratio) and toluene 50 parts by mass were added and stirred at 105 ° C. The temperature was raised to.
Further, a solution obtained by further diluting 2.2 parts by mass (solid content ratio) of radical initiator (manufactured by Nippon Finechem Co., Ltd., product name “ABN-E”) with 210 parts by mass of toluene in a reaction vessel was heated to 105 ° C. It was dripped over 4 hours, maintaining.
After completion of the dropping, the reaction was carried out at 105 ° C. for 6 hours to obtain a solution of an acrylic urethane resin having a mass average molecular weight of 105,000.

Production Example 2 (Preparation of adhesive sheet)
Details of the adhesive resin, additives, thermally expandable particles, base material, and release material used in the formation of each layer during the production of the following adhesive sheet are as follows.
<Adhesive resin>
Acrylic copolymer (i): having a structural unit derived from a raw material monomer consisting of 2-ethylhexyl acrylate (2EHA) / 2-hydroxyethyl acrylate (HEA) = 80.0 / 20.0 (mass ratio), An acrylic copolymer having a Mw of 600,000.
Acrylic copolymer (ii): n-butyl acrylate (BA) / methyl methacrylate (MMA) / 2-hydroxyethyl acrylate (HEA) / acrylic acid = 86.0 / 8.0 / 5.0 / 1. An acrylic copolymer having an Mw of 600,000 having a structural unit derived from a raw material monomer consisting of 0 (mass ratio).
<Additives>
Isocyanate crosslinking agent (i): manufactured by Tosoh Corporation, product name “Coronate L”, solid content concentration: 75 mass%.
<Thermal expandable particles>
Thermally expandable particles (i): manufactured by Kureha Corporation, product name “S2640”, expansion start temperature (t) = 208 ° C., average particle diameter before expansion at 23 ° C. (D ₅₀ ) = 24 μm, expansion at 23 ° C. Previous 90% particle size (D ₉₀ ) = 49 μm.
<Release material>
Heavy release film: manufactured by Lintec Corporation, product name “SP-PET382150”, a polyethylene terephthalate (PET) film provided with a release agent layer formed from a silicone release agent on one side, thickness: 38 μm.
Light release film: manufactured by Lintec Co., Ltd., product name “SP-PET381031”, a PET film provided with a release agent layer formed from a silicone release agent on one side, thickness: 38 μm.

(1) Formation of first pressure-sensitive adhesive layer (X1) To 100 parts by mass of the solid content of the acrylic copolymer (i), which is an adhesive resin, 5.0 parts by mass of the isocyanate-based crosslinking agent (i) ( (Solid content ratio) was mixed, diluted with toluene, and stirred uniformly to prepare a pressure-sensitive adhesive composition having a solid content concentration (active ingredient concentration) of 25% by mass.
And the said adhesive composition is apply | coated to the surface of the release agent layer of the said heavy release film, a coating film is formed, the said coating film is dried at 100 degreeC for 60 second, and a non-expandable adhesive of thickness 5 micrometers. The 1st adhesive layer (X1) which is an agent layer was formed.
The storage shear modulus G ′ (23) of the first pressure-sensitive adhesive layer (X1) at 23 ° C. was 2.5 × 10 ⁵ Pa.

(2) Formation of second pressure-sensitive adhesive layer (X2) To 100 parts by mass of the acrylic copolymer (ii), which is an adhesive resin, 0.8 parts by mass of the isocyanate-based crosslinking agent (i) ( (Solid content ratio) was mixed, diluted with toluene, and stirred uniformly to prepare a pressure-sensitive adhesive composition having a solid content concentration (active ingredient concentration) of 25% by mass.
And the said adhesive composition is apply | coated to the surface of the release agent layer of the said light release film, a coating film is formed, the said coating film is dried at 100 degreeC for 60 second, and 10 micrometers in thickness 2nd adhesive. Layer (X2) was formed.
The storage shear modulus G ′ (23) of the second pressure-sensitive adhesive layer (X2) at 23 ° C. was 9.0 × 10 ⁴ Pa.
Moreover, the adhesive force of the 2nd adhesive layer (X2) measured based on the said method was 1.0 N / 25mm.
Since it was clear that the second pressure-sensitive adhesive layer (X2) and the first pressure-sensitive adhesive layer (X1) had a probe tack value of 50 mN / 5 mmφ or more, measurement of the probe tack value was omitted.

(3) Production of substrate (Y) To 100 parts by mass of the solid content of the acrylurethane resin obtained in Production Example 1, 6.3 parts by mass (solid content ratio) of the isocyanate-based crosslinking agent (i), as a catalyst, Dioctyltin bis (2-ethylhexanoate) 1.4 parts by mass (solid content ratio) and the above-mentioned thermally expandable particles (i) are blended, diluted with toluene, stirred uniformly, and solid content concentration ( A resin composition having an active ingredient concentration of 30% by mass was prepared.
In addition, content of the thermally expansible particle (i) with respect to the whole quantity (100 mass%) of the active ingredient in the obtained resin composition was 20 mass%.
Then, the resin composition is formed on the surface of a 50 μm-thick polyethylene terephthalate (PET) film (product name “COSMO SHINE A4100”, probe tack value: 0 mN / 5 mmφ, manufactured by Toyobo Co., Ltd.), which is a non-intumescent substrate. The product was applied to form a coating film, and the coating film was dried at 100 ° C. for 120 seconds to form an expandable substrate layer (Y1) having a thickness of 50 μm.
Here, the PET film corresponds to the non-expandable base material layer (Y2).

In addition, as a sample for measuring the physical property value of the expandable base material layer (Y1), the resin composition is applied to the surface of the release agent layer of the light release film to form a coating film, and the coating film is formed into 100. Drying was performed at ° C for 120 seconds to similarly form an expandable substrate layer (Y1) having a thickness of 50 µm.
And based on the above-mentioned measuring method, the storage elastic modulus and probe tack value in each temperature of an expansible base material layer (Y1) were measured. The measurement results were as follows.
-Storage elastic modulus E '(23) at 23 ° C. = 2.0 × 10 ⁸ Pa
-Storage elastic modulus E '(208) at 208 ° C = 5.0 x 10 ⁵ Pa
・ Probe tack value = 0mN / 5mmφ
Moreover, the storage elastic modulus and probe tack value at each temperature of the PET film, that is, the non-expandable base material layer (Y2) were measured. The measurement results were as follows.
-Storage elastic modulus E '(23) at 23 ° C. = 1.0 × 10 ³ MPa
-Storage elastic modulus E '(208) at 208 ° C = 0.8 x 10 ² MPa
・ Probe tack value = 0mN / 5mmφ

(4) Lamination of each layer The non-intumescent base material layer (Y2) of the base material (Y1) prepared in (1-3) above and the second pressure-sensitive adhesive layer (X2) formed in (2) above are attached. At the same time, the thermally expandable base material layer (Y1) and the first pressure-sensitive adhesive layer (X1) formed in the above (1) were bonded together.
And the heavy release film / first pressure-sensitive adhesive layer (X1) / expandable base material layer (Y1) / non-expandable base material layer (Y2) / second pressure-sensitive adhesive layer (X2) / light release film in this order A pressure-sensitive adhesive sheet was prepared by laminating.

As for the pressure-sensitive adhesive sheets prepared on the basis of the above-described method, peel force (F ₀₎ and (F ₁₎ measured in accordance with the following methods.
As a result, the peel force (F ₀ ) = 0.23 N / 25 mm and the peel force (F ₁ ) = 0 mN / 25 mm, and the ratio between the peel force (F ₁ ) and the peel force (F ₀ ) [(F ₁ ) / (F ₀ )] was 0.

<Measurement of peeling force (F ₀ )>
The prepared pressure-sensitive adhesive sheet was allowed to stand for 24 hours in an environment of 23 ° C. and 50% RH (relative humidity), then the heavy release film of the pressure-sensitive adhesive sheet was removed, and the first pressure-sensitive adhesive layer (X1) exposed Was affixed to a silicon wafer.
Next, the end of the silicon wafer with the adhesive sheet attached is fixed to the lower chuck of the universal tensile testing machine (Orientec, product name “Tensilon UTM-4-100”), and the adhesive sheet is fixed with the upper chuck. did.
Then, in the same environment as above, peeling is performed at the interface P between the silicon wafer and the first pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet at a pulling speed of 300 mm / min according to JIS Z0237: 2000 by a 180 ° peeling method. The peeling force measured at the time of the measurement was defined as “peeling force (F ₀ )”.

<Measurement of peel force (F ₁ )>
The heavy release film of the prepared pressure-sensitive adhesive sheet is removed, and the exposed first pressure-sensitive adhesive layer (X1) is attached to a silicon wafer, heated at 240 ° C. for 3 minutes, and in the thermally expandable base material layer (Y1). The thermally expandable particles were expanded.
Thereafter, in the same manner as the measurement of the peeling force (F ₀ ) described above, the peeling force measured when peeling was performed at the interface P between the silicon wafer and the first pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet under the above conditions. Was defined as “peeling force (F ₁ )”.
When measuring the peel force (F ₁ ), the adhesive sheet (I) is completely separated from the silicon wafer when the adhesive sheet is fixed with the upper chuck of the universal tensile testing machine and cannot be fixed. The measurement was terminated, and the peeling force (F ₁ ) at that time was set to “0 mN / 25 mm”.

Example 1
<Step (1)>
The pressure-sensitive adhesive sheet produced in Production Example 2 was cut into a square size of 230 mm × 230 mm.
Using a tape grinder for back grind (manufactured by Lintec Corporation, device name “RAD-3510F / 12”), the heavy release film of the cut adhesive sheet was peeled off, and the first adhesive layer (X1) exposed was exposed. The adhesive surface was attached to a hard support (material: silicon, thickness: 725 μm, Young's modulus: 30 GPa). Further, the light release film was also peeled off, and nine semiconductor chips (the size of each chip was 6.4 mm long × 6.4 horizontal) on the adhesive surface of the exposed second pressure-sensitive adhesive layer (X2). X A rectangular parallelepiped shape having a thickness of 200 μm (# 2000) was placed at a certain interval so that the circuit surface on which the circuit was formed was in contact with the adhesive surface.

<Step (2)>
The nine semiconductor chips and the adhesive surface of the second adhesive layer (X2) at least in the periphery of the semiconductor chip are covered with a thermosetting sealing resin film as a sealing material, and heated in a vacuum Using a pressure laminator (“7024HP5” manufactured by ROHM and HAAS), the sealing resin film was thermally cured to produce a cured sealing body formed by sealing the semiconductor chip with a sealing material.
The sealing conditions are as follows.
-Preheating temperature: 100 ° C for both table and diaphragm
・ Vacuum drawing: 60 seconds ・ Dynamic press mode: 30 seconds ・ Static press mode: 10 seconds ・ Sealing temperature: 180 ° C. × 60 minutes Note that the semiconductor chip is not misaligned when covered with the above sealing resin film. Was not.

<Step (3)>
The temperature in the system including the hard support, the pressure-sensitive adhesive sheet, and the cured sealing body is set to 240 ° C. that is equal to or higher than the expansion start temperature (208 ° C.) of the thermally expandable particles (i), and the heat treatment is performed at the same temperature for 3 minutes. Went.
After the heat treatment, it could be easily separated at the interface between the hard support and the first pressure-sensitive adhesive layer (X1). At this time, the cured sealing body on the second pressure-sensitive adhesive layer (X2) remained laminated, and separation between the layers constituting the pressure-sensitive adhesive sheet did not occur.
Therefore, the surface of the hard support after the pressure-sensitive adhesive sheet is separated is not confirmed to remain in the first pressure-sensitive adhesive layer (X1), is not contaminated, and the surface of the hard support is newly cleaned. It is thought that there is no need to perform the process.
Further, the semiconductor chip sealed in the obtained cured sealing body was not misaligned, and no sealing resin was observed on the circuit surface.
Furthermore, about the cured sealing body with the pressure-sensitive adhesive sheet after being separated from the hard support, there is no adverse effect such as dropping of the first pressure-sensitive adhesive layer (X1) located in the outermost layer of the pressure-sensitive adhesive sheet. It can be said that the occurrence of contamination is suppressed.

1a, 1b Pressure-sensitive adhesive sheet (X1) First pressure-sensitive adhesive layer (X2) Second pressure-sensitive adhesive layer (Y) Base material (Y1) Expandable base material layer (Y2) Non-expandable base material layer (Y2-1) First Non-intumescent substrate layer (Y2-2) Second non-intumescent substrate layer 50 Hard support 60 Sealed object 61 Exposed surface 70 Sealant 80 Cured encapsulant

Claims

A substrate (Y) comprising at least an expandable substrate layer (Y1) containing expandable particles and a non-expandable substrate layer (Y2);
On both surfaces of the base material (Y), the first pressure-sensitive adhesive layer (X1) and the second pressure-sensitive adhesive layer (X2), which are non-intumescent pressure-sensitive adhesive layers,
By the expansion of the expandable particles, unevenness can occur on the adhesive surface of the first pressure-sensitive adhesive layer (X1), using a pressure-sensitive adhesive sheet, a method for producing a cured sealing body,
A method for producing a cured encapsulant comprising the following steps (1) to (3).
-Process (1): The process of sticking the adhesion surface of a 1st adhesive layer (X1) on a hard support body, and mounting a sealing target object on a part of adhesion surface of a 2nd adhesive layer (X2). .
Step (2): The sealing object and the adhesive surface of the second pressure-sensitive adhesive layer (X2) at least in the periphery of the sealing object are covered with a sealing material, and the sealing material is cured. And the process of obtaining the hardening sealing body formed by sealing the said sealing target object with the said sealing material.
Step (3): The expandable particles are expanded and the hard support and the first pressure-sensitive adhesive layer (X1) are stacked while the cured sealing body is laminated on the second pressure-sensitive adhesive layer (X2). Separating at the interface P.
The pressure-sensitive adhesive sheet has a first pressure-sensitive adhesive layer (X1) on the expandable substrate layer (Y1) side of the substrate (Y), and the non-expandable substrate layer ( The manufacturing method of the hardening sealing body of Claim 1 which has the said 2nd adhesive layer (X2) in the Y2) side.
The base material (Y) is a non-expandable base material layer (Y2) provided on the expandable base material layer (Y1) and the first adhesive layer (X1) side of the expandable base material layer (Y1). -1) and a non-intumescent substrate layer (Y2-2) provided on the second adhesive layer (X2) side of the expandable substrate layer (Y1),
The storage elastic modulus E ′ of the non-expandable base layer (Y2-1) when the expandable particles expand is determined by the storage modulus of the non-expandable base layer (Y2-2) when the expandable particles expand. The manufacturing method of the hardening sealing body of Claim 1 lower than elastic modulus E '.
The non-expandable base layer (Y2) is present at a position farther from the first pressure-sensitive adhesive layer (X1) than the expandable base layer (Y1), and the inflatable base layer (Y1) ) And the first pressure-sensitive adhesive layer (X1), the non-expandable base material layer (Y2) does not exist,
The storage elastic modulus E ′ of the non-expandable base layer (Y2) when the expandable particles expand is the storage elastic modulus E of the expandable base layer (Y1) when the expandable particles expand. The manufacturing method of the hardening sealing body of Claim 1 or 2 larger than '.
The method for producing a cured encapsulant according to any one of claims 1 to 4, wherein in the step (3), when the expandable particles are expanded, they are not separated between the layers constituting the pressure-sensitive adhesive sheet.
The method for producing a cured encapsulant according to any one of claims 1 to 5, wherein the expandable particles are thermally expandable particles having an expansion start temperature (t) of 60 to 270 ° C.
The cured sealing according to claim 6, wherein the expansion of the thermally expandable particles is performed by a heat treatment between “expansion start temperature (t) + 10 ° C.” to “expansion start temperature (t) + 60 ° C.” of the thermally expandable particles. Body manufacturing method.
The expandable substrate layer (Y1) is a thermally expandable substrate layer (Y1-1) containing the thermally expandable particles, and the storage elastic modulus E of the thermally expandable substrate layer (Y1-1) at 23 ° C. '(23) is 1.0 × 10 6 Pa or more. The method for producing a cured encapsulant according to claim 6 or 7.
The method for producing a cured encapsulant according to any one of claims 1 to 8, wherein a volume change rate (%) of the non-expandable base material layer (Y2) is less than 2% by volume.
The method for producing a cured encapsulant according to any one of claims 1 to 9, wherein the object to be encapsulated is a semiconductor chip.