JP6829998B2 - Adhesive sheet with base material and semiconductor module - Google Patents

Description

The present invention relates to an adhesive sheet with a base material and a semiconductor module.

Conventionally, a semiconductor module in which a semiconductor element is resin-molded is widely used, and since this semiconductor element generates heat when energized, various heat dissipation means are taken to prevent the junction temperature from exceeding a certain level. Has been done.
In general, this type of semiconductor module mounts a semiconductor element on a lead frame formed of a metal block called a heat spreader or a thick metal plate, and the heat spreader or lead frame quickly removes heat from the semiconductor element. It is configured to leave.
Conventionally, the heat generated in this type of semiconductor module is dissipated to the outside of the module through a metal member such as a heat radiation fin.

Here, reducing the thermal resistance value between the heat spreader or lead frame and the heat dissipation fins is advantageous for heat dissipation of the semiconductor module, but on the other hand, electrical insulation is provided between them for safety. It is required to secure it.
As a countermeasure against such a demand, the conventional semiconductor module is provided with an insulating layer formed of an epoxy resin composition containing an inorganic filler having a high thermal conductivity, and the heat radiation path from the semiconductor element to the outside is described above. An insulating layer is arranged.
Generally, the insulating layer is provided on the semiconductor module in a state of being adhered to the heat spreader or the lead frame, and is adhered to the surface of the heat spreader or the lead frame opposite to the surface on which the semiconductor element is mounted.
In such a case, there is a wide range of methods in which a thermosetting adhesive sheet is once prepared from an epoxy resin composition, and the thermosetting adhesive sheet is adhered to a heat spreader or a lead frame and then thermoset to form the insulating layer. It has been adopted.
An epoxy resin composition using an epoxy resin as a base polymer generally has excellent electrical insulation and heat resistance and exhibits good adhesiveness to a wide range of materials, but when it is highly filled with an inorganic filler, it becomes brittle and easily cracked. ..
Therefore, the thermosetting adhesive sheet is laminated on a base sheet such as a copper foil or a resin film so as not to cause inadvertent cracking, and is handled in the state of an adhesive sheet with a base material.

This base material sheet is used not only as a release liner that is peeled off from the thermosetting adhesive sheet after adhering the thermosetting adhesive sheet to a heat spreader or a lead frame, but also when the base material sheet is a copper foil. Is used as it is as a constituent member of a semiconductor module without being peeled off from a thermosetting adhesive sheet (see Patent Documents 1 and 2 below).
Further, this type of adhesive sheet with a base material is also used in addition to the semiconductor module, and is also used as a member for forming a heat sink with an insulating layer as shown in Patent Document 3 below. ing.
Such an adhesive sheet with a base material is produced by a method in which the raw material sheet is individually separated by cutting with a share cutter or punching with a punching press as described in paragraph 0058 of Patent Document 3 below. Has been done.

Japanese Unexamined Patent Publication No. 2015-021025 JP-A-2015-189609 JP-A-2009-130251

The adhesive sheet with a base material is supplied to the laminating device in the state of a laminated body in which a plurality of sheets are stacked in a rod with the outer peripheral edges aligned, and the adhesive sheets are taken out one by one from the laminated body and used as a heat spreader, a lead frame, or the like. It is used in such a form that it is adhered and then the base sheet is peeled off as needed.

The adhesive sheet with a base material is required to adhere to the thermosetting adhesive sheet until the adhesion to the mating member to be adhered is completed.
If the base sheet and the thermosetting adhesive sheet are easily peeled off, the base material sheet may be peeled off when cutting for individualization, or the base material may be peeled off when taken out from the laminate. The sheet and the thermosetting adhesive sheet may not be taken out as a set, resulting in poor handleability.
On the other hand, if the base sheet and the thermosetting adhesive sheet are firmly adhered to each other, the peelability becomes poor when the base sheet is used as a release liner, and it becomes difficult to handle.
That is, the conventional adhesive sheet with a base material has a problem that it is not sufficiently easy to handle.
Further, for that reason, the conventional semiconductor module has a problem that it is not sufficiently easy to manufacture.

The present invention has been made in view of the above, and an object of the present invention is to provide an adhesive sheet with a base material that is easy to handle, and by extension, to provide a semiconductor module that is easy to manufacture.

In order to solve the above problems, the present invention comprises a thermosetting adhesive sheet formed of an epoxy resin composition containing an epoxy resin and an inorganic filler having a higher thermal conductivity than the epoxy resin, and the thermosetting adhesive sheet. An adhesive sheet with a base material provided with a base material sheet for supporting the above, wherein the thermosetting adhesive sheet is a surface opposite to a first adhesive surface to be adhered to a mating member and the first adhesive surface. It has a second adhesive surface that is an adhesive surface with the base sheet, and the base sheet is a first surface that is an adhesive surface with the thermosetting adhesive sheet and an opposite surface to the first surface. An adhesive sheet with a base material which has a second surface and a part or all of the outer peripheral end faces of the base material sheet is an inclined surface which extends outward from the side of the first surface toward the side of the second surface. I will provide a.

Further, the present invention is a semiconductor module provided with a semiconductor element in order to solve the above-mentioned problems, and heat generated from the semiconductor element is dissipated through a metal member for heat dissipation. The semiconductor element and the metal member Provided is a semiconductor module which is provided with an insulating layer for electrically insulating between the semiconductor module and the semiconductor module in which the insulating layer is formed by the heat-curable adhesive sheet of the adhesive sheet with a base material as described above.

The adhesive sheet with a base material of the present invention has an inclined surface that expands outward from the side where a part or all of the outer peripheral end surface of the base material sheet is adhered to the thermosetting adhesive sheet to the opposite side.
In other words, the base sheet is in a state in which the side opposite to the side to which the thermosetting adhesive sheet is adhered protrudes outward.
Therefore, the adhesive sheet with a base material of the present invention can be easily taken out by using the hook of the protruding portion of the base material sheet when only one sheet is taken out from the laminated state, and the base material sheet is thermoset. Even if the adhesive sheet is relatively strongly adhered to the adhesive sheet, the base sheet can be easily peeled off from the thermosetting adhesive sheet by utilizing this hook.
That is, the adhesive sheet with a base material of the present invention has improved handleability as compared with the conventional one, and can facilitate the formation of an insulating layer of a semiconductor module.

The schematic cross-sectional view which shows the structure of the semiconductor module of one Embodiment. The schematic side view which shows the adhesive sheet with a base material. An enlarged view of an enlarged portion related to the broken line circle A in FIG. The schematic cross-sectional view which shows the structure of the semiconductor module of another embodiment.

Hereinafter, preferred embodiments of the present invention will be described.
FIG. 1 is a view showing a cross section of the semiconductor module according to the present embodiment, and as shown in FIG. 1, the semiconductor module 100 of the present embodiment has an insulating layer 10.
The insulating layer 10 is formed of an adhesive sheet 1 with a base material having a two-layer structure as shown in FIG.
More specifically, the adhesive sheet 1 with a base material of the present embodiment is a thermosetting adhesive sheet 10 formed of an epoxy resin composition containing an epoxy resin and an inorganic filler having a higher thermal conductivity than the epoxy resin. 'And a base sheet 20'supporting the thermosetting adhesive sheet 10' are provided.
The thermosetting adhesive sheet 10'of the adhesive sheet 1 with a base material is used for forming the insulating layer 10.

In the insulating layer 10 formed by the thermosetting adhesive sheet 10', the first surface 10a is directed to the inside of the semiconductor module 100, and the second surface 10b constitutes the outer surface of the semiconductor module 100.
The semiconductor module 100 of the present embodiment is a flat rectangular parallelepiped having a low height, and a part of the bottom surface thereof is formed by the second surface 10b of the insulating layer 10.
That is, the insulating layer 10 is arranged along the bottom surface of the semiconductor module 100, and is arranged in the semiconductor module 100 so that the plane direction is the horizontal direction.

The semiconductor module 100 further includes a heat spreader 30 mounted on the insulating layer 10.
The heat spreader 30 is formed of a metal block having a flat rectangular parallelepiped shape smaller than that of the semiconductor module 100, and the first surface 10a of the insulating layer 10 is adhered to the lower surface thereof.
A solder 40 and a semiconductor element 50 fixed to the upper surface of the heat spreader 30 by the solder 40 are provided on the upper surface side of the heat spreader 30.

The semiconductor element 50 is smaller than the heat spreader 30, and is mounted on the heat spreader 30 in a bare chip state in the present embodiment.
The semiconductor module 100 of the present embodiment includes a heat spreader 30 and a semiconductor element 50, and includes a rectangular frame-shaped case 60 forming an outer shell of the semiconductor module 100.
More specifically, the case 60 has a peripheral frame shape having openings at the top and bottom.
The semiconductor module 100 includes a lead frame 70 that penetrates the case 60 and extends inside and outside the module, a bonding wire 80 that electrically connects the semiconductor element 50 and the lead frame 70, and a resin mold filled in the case 60. It has 90 and.

The bottom surface of the semiconductor module 100 has a central portion formed by the second surface 10b of the insulating layer 10, an outer peripheral portion formed by the lower end surface of the case 60, and a portion between the case 60 and the insulating layer 10. It is formed by a resin mold 90.
The semiconductor module 100 is used by abutting the second surface 10b of the insulating layer 10 with a metal member for heat dissipation (heat dissipation fins, water circulation type forced cooler, etc.) (not shown).
That is, the semiconductor module 100 of the present embodiment includes the semiconductor element 50, and the heat generated from the semiconductor element 50 is dissipated through a metal member such as a heat radiating fin, and the semiconductor element 50 and the metal member are dissipated. An insulating layer 10 is provided to electrically insulate between the two.

As described above, in the semiconductor module 100 of the present embodiment, the insulating layer 10 is formed of an adhesive sheet 1 with a base material.
The adhesive sheet 1 with a base material has a two-layer structure of a thermosetting adhesive sheet 10'and a base material sheet 20'.

As described above, in the thermosetting adhesive sheet 10', the mating member to be adhered to form the insulating layer 10 is the heat spreader 30.
The thermosetting adhesive sheet 10'is a second adhesive surface between the first adhesive surface 10a'adhering to the heat spreader 30 and the base sheet 20', which is the opposite surface of the first adhesive surface 10a'. It has an adhesive surface 10b'.
On the other hand, the base material sheet 20'has a first surface 20a'adhered to the thermosetting adhesive sheet 10'and a second surface 20b'opposite to the first surface 20a'.
A part or all of the outer peripheral end surface 20c'of the base material sheet 20'is an inclined surface that expands outward from the side of the first surface 20a'to the side of the second surface 20b'.
That is, in general, the angle formed by the outer peripheral end faces of the sheet body and both surfaces is about 90 degrees, but the base sheet 20'of the present embodiment has the outer peripheral end faces 20c at the inclined surface. The angle between'and the first surface 20a'is an obtuse angle, and the angle between the outer peripheral end surface 20c'and the second surface 20b'is an acute angle.

In the adhesive sheet 1 with a base material of the present embodiment, the entire outer peripheral end surface 20c'of the base material sheet 20' spreads outward from the side of the first surface 20a'to the side of the second surface 20b' as described above. It is an inclined surface.
That is, in the base material sheet 20'of the present embodiment, the position of the outer edge of the first surface 20a'and the position of the outer edge of the second surface 20b' have a difference in the plane direction, and the position of the outer edge of the first surface 20a' When a virtual perpendicular line ax1 is drawn from the outer edge toward the second surface 20b', a constant distance D (D) is provided between the intersection P of the virtual perpendicular line ax1 and the second surface 20b'and the outer edge of the second surface 20b'. > 0).
In other words, the second surface 20b'of the base sheet 20'is in a state of protruding outward from the first surface 20a'.

In the portion protruding outward from the first surface 20a', the thermosetting adhesive sheet 10'is bonded to the heat spreader 30, and then the base sheet 20'is attached to the second adhesive surface 10b'of the thermosetting adhesive sheet 10'. It is a part that can be used as a hooking part for peeling, and is a part that serves as a starting point for peeling.
When peeling the base sheet 20', first, at any part of the outer peripheral edge of the base sheet 20', the end portion of the base sheet 20'is peeled away from the thermosetting adhesive sheet 10'. It is necessary to provide a portion that serves as a starting point for peeling.
In the base material sheet 20'of the present embodiment, since the second surface 20b'projects outward by a certain distance D from the outer edge of the first surface 20a', this protrusion can be used as a hooking allowance.
In the adhesive sheet 1 with a base material of the present embodiment, since the entire outer peripheral end surface 20c'of the base material sheet 20'is an inclined surface, any point on the outer peripheral edge can be used as a peeling starting point.

In the conventional adhesive sheet with a base material of the same type, since the outer peripheral end surface of the base material sheet is perpendicular to the plane direction, there is no hooking allowance as described above.
Therefore, the adhesive sheet 1 with a base material of the present embodiment has excellent peelability as compared with the conventional one.

In the present embodiment, a part or all of the outer peripheral end surface 10c'of the thermosetting adhesive sheet 10'also spreads outward from the side of the first adhesive surface 10a'to the side of the second adhesive surface 10b'. It is an inclined surface.
The second adhesive surface 10b'of the thermosetting adhesive sheet 10'has the same shape as the first surface 20a' of the base sheet 20'.
The first adhesive surface 10a'of the thermosetting adhesive sheet 10'has a smaller area than the second adhesive surface 10b'.
Therefore, in the adhesive sheet 1 with a base material of the present embodiment, when the thermosetting adhesive sheet 10'is adhered to the heat spreader 30, from the outer edge of the adhesive surface to the outer edge of the second surface 20b'of the base material sheet 20'. Can be greater than the distance D from the outer edge of the first surface 20a'.
That is, since the outer peripheral end surface 10c'of the thermosetting adhesive sheet 10'is an inclined surface, the adhesive sheet 1 with a base material of the present embodiment secures a larger hooking allowance when the base material sheet 20'is peeled off. can do.

The inclination angle θ1 (elevation angle of the inclined surface with respect to the second adhesive surface 10b') of the outer peripheral end surface 10c'of the thermosetting adhesive sheet 10'and the inclination angle θ2 (second surface 20b) of the outer peripheral end surface 20c' of the base sheet 20'. The smaller the elevation angle of the inclined surface with respect to') is advantageous in securing a larger hooking allowance at the time of peeling.
On the other hand, considering that the adhesive sheet 1 with a base material is produced by a method of individualizing a raw material sheet having a larger area than the adhesive sheet with a base material 1, the inclination angles θ1 and θ2 are small. Means that the thermosetting adhesive sheet is likely to be wasted.
That is, when individual pieces (adhesive sheet with a base material) cut out from the raw material sheet are allocated on the raw material sheet, even if the base sheet sides are closely adjacent to each other, if the inclination angles θ1 and θ2 are small, the thermosetting adhesive sheet side A large gap is generated between adjacent pieces, and it is not always preferable that the inclination angles θ1 and θ2 are small in consideration of the yield of the product.

Therefore, the angle (θ1) of the inclined surface of the thermosetting adhesive sheet 10'is preferably 45 degrees or more and less than 90 degrees, more preferably 50 degrees or more and 85 degrees or less, and more preferably 60 degrees or more. It is particularly preferable that the temperature is 80 degrees or less.
Similarly, the angle (θ2) of the inclined surface of the base sheet 20'is preferably 45 degrees or more and less than 90 degrees, more preferably 50 degrees or more and 85 degrees or less, and 60 degrees or more and 80 degrees or less. Is particularly preferred.
The above-mentioned angle means an angle observed in a cross section of the base-attached adhesive sheet 1 cut along a plane orthogonal to the direction of orbiting the outer peripheral edge of the base-attached adhesive sheet 1.

The angle of the inclined surface of the thermosetting adhesive sheet 10'(θ1) and the angle of the inclined surface of the base sheet 20'(θ2) may be common to at least a part of the outer peripheral end surfaces 10c'and 20c'. It is preferable that all of them are common.
If the angle (θ1) of the inclined surface of the thermosetting adhesive sheet 10'is larger than the angle (θ2) of the inclined surface of the base sheet 20', a complicated process is required for individualization from the raw material sheet. become.
Therefore, the angle (θ1) of the inclined surface of the thermosetting adhesive sheet 10'is preferably equal to or less than the angle (θ2) of the inclined surface of the base sheet 20'.

By making the angles (θ1, θ2) of the inclined surfaces common to at least a part as described above, the outer peripheral end surface 10c'of the thermosetting adhesive sheet becomes flush with the outer peripheral end surface 20c' of the base sheet, and the portion concerned. It can facilitate cutting.
If the angle of the inclined surface of the thermosetting adhesive sheet 10'(θ1) and the angle of the inclined surface of the base sheet 20'(θ2) are different, "cutting out" and "outer peripheral end surface" are used for individualization from the raw material sheet. At least two steps with "processing" are required, but if the inclination angles are common, individualization can be carried out in one step.

The thicker the thermosetting adhesive sheet 10'is advantageous for exhibiting excellent insulation reliability with respect to the semiconductor module 100, but the thinner one is preferable from the viewpoint of heat dissipation.
Therefore, the thermosetting adhesive sheet 10'in the present embodiment preferably has an average thickness of 10 μm or more and 1000 μm or less, more preferably 25 μm or more and 500 μm or less, and 50 μm or more and 250 μm or less. Especially preferable.

The thicker the base sheet 20', the more reliably it can prevent the thermosetting adhesive sheet 10' from cracking, but the thinner the base sheet 20', the easier it is to peel off from the thermosetting adhesive sheet 10'.
For this reason, the base sheet 20'in the present embodiment preferably has an average thickness of 5 μm or more and 500 μm or less, more preferably 10 μm or more and 250 μm or less, and particularly preferably 25 μm or more and 150 μm or less. ..

The thermosetting adhesive sheet 10'of this embodiment is formed of an epoxy resin composition containing an epoxy resin and an inorganic filler having a higher thermal conductivity than the epoxy resin.
In the thermosetting adhesive sheet 10'of the present embodiment, at least one of the adhesive sheet 1 with a base material and the mating member (heat spreader 30) is heated so as to have a temperature equal to or higher than the softening point of the epoxy resin. Is glued to.
At this time, when the thermosetting adhesive sheet 10'is in an excessively heated and melted state and exhibits high fluidity, the epoxy resin composition forming the thermosetting adhesive sheet 10'protrudes to the outside of the base sheet 20'. There is a risk that it will end up.
Epoxy resin composition that forms such a thermosetting adhesive sheet 10 since ', when heated to 175 ° C., preferably showing a viscosity of greater than ^{1 × 10 7 Pa · s,} 1 × 10 8 Pa -It is more preferable to show a viscosity exceeding s.
If the epoxy resin composition has an excessively low fluidity, the adhesiveness with the heat spreader 30 may not be sufficiently good.
Therefore, the viscosity of the epoxy resin composition when heated to 175 ° C. is preferably less than 1 × 10 ¹⁰ Pa · s, and more preferably less than 1 × 10 ⁹ Pa · s.

The viscosity of the epoxy resin composition (thermosetting adhesive sheet) when heated to 175 ° C. can be determined, for example, by the following method.
(Viscosity measurement method)
That is, a measurement sample having a size of 10 mm (width) × 50 mm (length) × 200 μm (thickness) is prepared from an epoxy resin composition (thermosetting adhesive sheet), and both ends of the measurement sample in the length direction are formed. The viscosity can be determined under the following conditions by clamping with the measuring head of the following device.
The viscosity of the epoxy resin composition when heated to 175 ° C. means the lowest value of the viscosity observed after the temperature is raised under the following conditions and the measurement temperature reaches 175 ° C., and is usually the measurement temperature. Means the value of viscosity observed when the temperature reaches 175 ° C.

Measuring device: ARES (manufactured by TA Instruments)
Measurement conditions Measurement mode: torsion (free)
Frequency / Distortion: 1Hz / 0.03%
Measurement length: 33 mm
Heating rate: 10 ° C / min (30 ° C → 175 ° C)
Evaluation temperature / time: 175 ° C isothermal maintenance 30 minutes

The epoxy resin composition is preferably highly filled with an inorganic filler in order to exhibit excellent thermal conductivity in the thermosetting adhesive sheet.
Examples of the inorganic filler include inorganic nitride fillers such as boron nitride, aluminum nitride, and silicon nitride, and inorganic oxidation such as silicon oxide (silica), aluminum oxide (alumina), titanium oxide (titania), and zirconia oxide (zirconia). Examples include material fillers, diamonds, talc, clay, and calcium carbonate.
Among them, the inorganic filler contained in the heat-curable adhesive sheet is preferably any one of boron nitride, aluminum oxide, and silicon oxide, and is a mixture containing at least boron nitride and aluminum oxide, or More preferably, it is at least one of a mixture containing boron nitride and silicon oxide.
Further, the mixed product preferably has a boron nitride content of 50% by mass or more and 95% by mass or less.

The heat-curable adhesive sheet preferably has a thermal conductivity of 5 W / m · K or more, more preferably has a thermal conductivity of 7 W / m · K or more, and has a thermal conductivity of 10 W / m · K or more. It is particularly preferable to have a rate.
The content of the inorganic filler in the thermosetting adhesive sheet is limited due to the adhesiveness, mechanical strength, and the like, and the thermal conductivity is usually 20 W / m · K or less.

The content of boron nitride in the thermosetting adhesive sheet is preferably 30% by volume or more, more preferably 40% by volume or more, and particularly preferably 50% by volume or more.

The thermosetting adhesive sheet preferably has a 1 × 10 ¹² Ω · cm or more volume resistivity, volume resistivity is more preferably exhibits 1 × 10 ¹³ Ω · cm or more electrically insulating.
Since the thermosetting adhesive sheet is highly filled with an inorganic filler, it is difficult to expect excessive electrical insulation, and the volume resistivity is usually 1 × 10 ¹⁸ Ω · cm or less.

The content of boron nitride in the thermosetting adhesive sheet is preferably 65% by volume or less in view of the electrical insulation and mechanical properties of the thermosetting adhesive sheet.

When the content of boron nitride is 30% by volume or more, the thermosetting adhesive sheet can have good thermal conductivity. Further, from the viewpoint of exhibiting excellent adhesiveness, mechanical strength, and electrical insulation of the thermosetting adhesive sheet, the boron nitride content is preferably 65% by volume or less. In addition, this volume ratio means the ratio at 20 degreeC.

In order to develop the preferable viscosity at 175 ° C. as described above in the thermosetting adhesive sheet, the thermosetting adhesive sheet preferably contains the boron nitride as an aggregate, and the silica. Is preferably contained as fumed silica.
The fumed silica may be contained in the thermosetting adhesive sheet at a ratio of 0.5 parts by mass or more and 20 parts by mass or less when the content of boron nitride in the thermosetting adhesive sheet is 100 parts by mass. It is preferably contained in the thermosetting adhesive sheet in a proportion of 1 part by mass or more and 10 parts by mass or less.
As the boron nitride as an agglomerate, it is preferable that the volume-based average particle diameter determined by the laser diffraction / scattering method is 10 to 200 μm.
As the fumed silica, the volume-based average particle size determined by the laser diffraction / scattering method is preferably 1 μm or less, and the average particle size is preferably 2 to 100 nm.

The epoxy resin constituting the thermosetting adhesive sheet together with such an inorganic filler is not particularly limited, and for example, a triphenylmethane type epoxy resin, a cresol novolac type epoxy resin, a biphenyl type epoxy resin, and a modified bisphenol A type epoxy. Various epoxy resins such as resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, modified bisphenol F type epoxy resins, dicyclopentadiene type epoxy resins, phenol novolac type epoxy resins, and phenoxy resins can be used.
These epoxy resins may be used alone or in combination of two or more.
Among them, the epoxy resin contained in the thermosetting adhesive sheet is preferably a triphenylmethane type epoxy resin, and 80% by mass or more of the epoxy resin contained in the thermosetting adhesive sheet is preferably a triphenylmethane type epoxy resin. ..

The epoxy resin composition forming the thermosetting adhesive sheet can further contain a curing agent and a curing accelerator.
The curing agent is not particularly limited, and is, for example, a phenol-based curing agent such as a phenol novolac resin, an aralkyl-type phenol resin, a dicyclopentadiene-modified phenol resin, a naphthalene-type phenol resin, or a bisphenol-based phenol resin, or diamino. Examples thereof include amine-based curing agents such as diphenylsulfone, dicyandiamide, diaminodiphenylmethane, and triethylenetetramine, and acid anhydride-based curing agents.
Among them, as the curing agent contained in the epoxy resin composition, an aralkyl type phenol resin such as xylylene novolac phenol or biphenyl novolac phenol is preferable.
The curing accelerator is not particularly limited, but amine-based curing accelerators such as imidazoles, triphenylphosphate (TPP), and boron trifluoride monoethylamine are suitable in terms of storage stability and the like.

The epoxy resin composition may contain various additives in addition to the above.
As the additive, it is generally used as a plastic compounding chemical such as a dispersant, a tackifier, an antiaging agent, an antioxidant, a processing aid, a stabilizer, a defoaming agent, a flame retardant, a thickener, and a pigment. Things can be mentioned.

In producing the adhesive sheet 1 with a base material of the present embodiment, a method of producing a raw material sheet having a larger area than that of the adhesive sheet 1 with a base material and individualizing the raw material sheet can be adopted.
In the raw material sheet, an epoxy resin composition is varnished using an organic solvent, and this varnish is continuously applied to a strip-shaped base material that is wider and longer than the base material sheet and dried to form a dry coating film. The prepared primary sheet is obtained, and the two primary sheets are laminated and pressed so that the dry coating film is on the inside to obtain a secondary sheet in which the two primary sheets are integrated, and one of the secondary sheets is obtained. It can be produced by removing the strip-shaped base material of.

As a first method for producing an individual adhesive sheet 1 with a base material from a raw material sheet, for example, a method in which an individual piece is once produced by a shear cutter or a punching press and then the outer peripheral end surface of the individual piece is diagonally polished can be mentioned. Be done.
Instead of such a method, a second method of cutting out individual pieces with a laser cutter, a wire saw, etc., and cutting out the individual pieces so that the cutting direction by these is inclined with respect to the thickness direction of the raw material sheet is used. It may be carried out.
Further, instead of the first method and the second method described above, a V-groove is formed with a rotary grindstone having a thin outer peripheral edge and a thick central portion like an abacus or a disc cutter that tapers toward the outer peripheral edge. The individual pieces may be produced by a third method of cutting the raw material sheet in an abacus shape.
These methods depend on the forming material and thickness of the thermosetting adhesive sheet 10'and the base sheet 20', but the third method is for two adjacent adhesive sheets with a base material in the raw material sheet. It is preferable in that an inclined surface can be formed at one time.

The strip-shaped base material to be the base material sheet is made of electrolytic copper foil or matte pet (a surface-roughened PET film) in that it can prevent varnish repelling and exhibits good adhesiveness to an epoxy resin composition. Suitable.
Among them, electrolytic copper foil is suitable as a raw material for a base sheet that exhibits excellent adhesiveness to a thermosetting adhesive sheet.
That is, in the adhesive sheet 1 with a base material of the present embodiment, the base material sheet 20'is an electrolytic copper foil, and the matte surface of the glossy surface and the matte surface of the electrolytic copper foil is the first surface 20a'. It is preferable that

The base sheet 20'in the present embodiment is used as a release liner that is peeled off from the second adhesive surface 10b'of the thermosetting adhesive sheet 10'after the thermosetting adhesive sheet 10'is bonded to the mating member. ..
At this time, since the outer peripheral end surface of the base sheet 20'is an inclined surface, the base sheet 20'can be easily peeled off from the thermosetting adhesive sheet 10'.

The case where the use of the adhesive sheet 1 with a base material is used for forming the insulating layer 10 of the semiconductor module 100 is illustrated, but the use of the adhesive sheet 1 with a base material of the present invention is illustrated as described above. It is not limited.
Further, in the present embodiment, the case where the base sheet 20'is used as a release liner is illustrated, but the base sheet 20'is not peeled from the thermosetting adhesive sheet 10' if necessary. It may be used as a material for forming the semiconductor module 100 (see FIG. 4).
That is, when the semiconductor module 100 having the metal foil layer 20 forming the heat radiating surface and the insulating layer 10 in contact with the metal foil layer 20 from the inside is formed as shown in FIG. 4, the metal foil layer 20 is formed. The insulating layer 10 may be formed by the adhesive sheet 1 with a base material and then formed by using a metal foil different from the base material sheet 20', but it may also be formed by not peeling off the base material sheet 20'. It is possible.

Further, various changes can be made to the adhesive sheet with a base material and the semiconductor module of the present embodiment.
That is, the adhesive sheet with a base material and the semiconductor module of the present invention are not limited to the above examples.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.
An adhesive sheet with a base material was prepared by laminating a base material sheet formed of an electrolytic copper foil (thickness 70 μm) and a thermosetting adhesive sheet (thickness 150 μm) formed of an epoxy resin composition.
At this time, the viscosity of the first epoxy resin composition (EPX1) having a viscosity at 175 ° C. of 2 × 10 ⁸ Pa · s and the viscosity of the second epoxy resin composition (EPX2) having a viscosity of 1 × 10 ⁷ Pa · s. Using 3 types of epoxy resin compositions with a 3rd epoxy resin composition (EPX3) of 2 × 10 ⁶ Pa · s, 3 types of adhesive sheets with a base material having different materials of the thermosetting adhesive sheet (sheet) # 1 to Sheet # 3) Prepared.
In these adhesive sheets with a base material, both the base material sheet and the thermosetting adhesive sheet have the entire outer peripheral end surface as an inclined surface, and the angle (θ1) of the inclined surface of the thermosetting adhesive sheet , The angle (θ2) of the inclined surface of the base sheet was 80 degrees for both.
Regarding the adhesive sheet with a base material (sheet # 2) using the second epoxy resin composition (EPX2), the angle (θ1) of the inclined surface of the thermosetting adhesive sheet and the inclined surface of the base material sheet An adhesive sheet with a base material (sheet # 2') having an angle (θ2) of 70 degrees and an adhesive sheet with a base material (sheet # 2 ") having an angle (θ2) of 60 degrees were also produced.

For comparison, an adhesive sheet with a base material having a vertical outer peripheral end face was prepared, a thermosetting adhesive sheet was adhered to a metal plate using a hot press, and after cooling, the electrolytic copper foil was peeled off.
As a result, the peeling work is easier than that of the adhesive sheet with a base material whose end faces are vertical in all of the sheet # 1, the sheet # 2, the sheet # 2', the sheet # 2 ", and the sheet # 3. Was confirmed.
Further, when the inclination angle of the outer peripheral end surface of the thermosetting adhesive sheet after being bonded to the metal plate was measured again, it was found that the angle changed to a shape approaching vertical except for the sheet # 1.
In particular, in sheet # 3, it was observed that the epoxy resin composition flowed at the edge portion and protruded to the outside of the base sheet.
These results are shown in Table 1.

From the above, it can be seen that according to the present invention, an adhesive sheet with a base material that is easy to handle can be provided.

1 Adhesive sheet with base material 10 Insulation layer 10'Thermosetting adhesive sheet 20 Metal leaf layer 20' Base material sheet 30 Heat spreader 50 Semiconductor element 100 Semiconductor module

Claims (6)

A group provided with a thermosetting adhesive sheet formed of an epoxy resin composition containing an epoxy resin and an inorganic filler having a higher thermal conductivity than the epoxy resin, and a base sheet supporting the thermosetting adhesive sheet. It is an adhesive sheet with material,
The thermosetting adhesive sheet has a first adhesive surface that adheres to a mating member, and a second adhesive surface that is opposite to the first adhesive surface and is an adhesive surface to the base material sheet.
The base material sheet has a first surface which is an adhesive surface with the thermosetting adhesive sheet and a second surface which is an opposite surface of the first surface.
Some or all of the outer peripheral edge surface of the substrate sheet, Ri inclined surfaces der to be splayed toward the side of the second surface from the side of the first surface,
The epoxy resin composition, the adhesive sheet having a substrate exhibiting a viscosity of greater than 1 × 10 8 ^Pa · s when heated to 175 ° C.. The adhesive sheet with a base material according to claim 1, wherein the entire outer peripheral end surface of the base material sheet is the inclined surface. The adhesive sheet with a base material according to claim 1 or 2, wherein the base material sheet is used as a release liner. The adhesive sheet with a base material according to any one of claims 1 to 3, wherein the base material sheet is an electrolytic copper foil, and the matte surface of the electrolytic copper foil is used as the first surface. The adhesive sheet with a base material according to any one of claims 1 to 4, wherein a part or all of the outer peripheral end surface of the thermosetting adhesive sheet is an inclined surface that is flush with the inclined surface of the base material sheet. .. A semiconductor module provided with a semiconductor element, in which heat generated from the semiconductor element is dissipated through a metal member for heat dissipation.
A thermosetting adhesive sheet with a base material according to any one of claims 1 to 5 is provided with an insulating layer for electrically insulating the semiconductor element and the metal member. A semiconductor module in which the insulating layer is formed by a sheet.