JP2019065354A - Film-like firing material, and film-like firing material with support sheet - Google Patents

Abstract

To provide a film-like firing material excellent in thickness stability and thermal conductivity, capable of being fired at a low temperature, and exhibiting excellent shear adhesive force after firing, and a film-like firing material with a support sheet.SOLUTION: There is provided a film-like firing material 1 containing a sinterable metal particle and a binder component, having a temperature with the largest negative tilt in a heat weight curve (TG curve) measured from 40°C to 600°C at temperature rise rate of 10°C/min. under ambient air atmosphere within a range of 200°C to 350°C, and a value by deducting the smallest weight residual rate (%) from 200°C to 350°C from weight residual rate (%) at 200°C within a range of 5% to 20%.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a film-like fired material and a film-like fired material with a support sheet.

In recent years, with the increasing voltage and current of automobiles, air conditioners, personal computers, etc., the demand for power semiconductor elements (power devices) mounted on these has been increasing. Since the power semiconductor element is used under high voltage and high current, the generation of heat from the semiconductor element tends to be a problem.
Heretofore, a heat sink may be attached around a semiconductor element to dissipate heat generated from the semiconductor element. However, if the thermal conductivity at the junction between the heat sink and the semiconductor element is not good, efficient heat dissipation will be impeded.

  As a bonding material excellent in thermal conductivity, for example, Patent Document 1 discloses paste-like metal fine particles in which a specific heat-sinterable metal particle, a specific polymer dispersant, and a specific volatile dispersion medium are mixed. A composition is disclosed. When the composition is sintered, it becomes a solid metal excellent in thermal conductivity.

JP, 2014-111800, A

However, when the fired material is in the form of paste as in Patent Document 1, it is difficult to make the thickness of the applied paste uniform, and the thickness stability tends to be poor.
The present invention has been made in view of the above-described actual conditions, and is a film-like fired material excellent in thickness stability and thermal conductivity, capable of being fired at a low temperature, and exhibiting excellent shear adhesion after firing. Intended to provide. Moreover, it aims at providing a film-like baking material with a support sheet provided with the said film-like baking material.

  Heretofore, it has been considered that the lower the thermal decomposition temperature, the better for materials other than metal particles contained in the fired material. However, by examining the sintering mechanism from the viewpoint of thermal physical properties, the present inventors have found that the film-like fired material having a specific relationship between the temperature and the weight retention rate in the thermal weight curve (TG curve) has a thickness. The inventors have found that they are excellent in stability and thermal conductivity, can be fired at low temperatures, and can exhibit excellent shear adhesion after firing, and completed the invention.

That is, the present invention includes the following aspects.
[1] A film-like fired material containing sinterable metal particles and a binder component, the thermogravimetric curve (TG curve) measured from 40 ° C. to 600 ° C. at a temperature rising rate of 10 ° C./minute in the atmosphere. The temperature at which the negative slope is the largest is in the range of 200 ° C to 350 ° C, and the weight remaining rate (%) at 200 ° C is the smallest weight remaining rate (%) from 200 ° C to 350 ° C. A film-like baked material characterized in that the value obtained by subtracting is in the range of 5% to 20%.
[2] The thermal weight curve (TG curve) measured from 40 ° C. to 600 ° C. at a temperature rising rate of 10 ° C./min in the atmosphere for the component obtained by removing the sinterable metal particles from the film-like fired material The temperature (A ') at which the negative slope is the largest and the differential thermal analysis curve of the sinterable metal particles measured using an alumina particle as a reference sample at a heating rate of 40 ° C to 600 ° C in an air atmosphere at 10 ° C / min. Peak temperature (B ') observed at the lowest temperature in (DTA curve),
The film-like fired material according to the above [1], wherein B satisfies the relationship of B ′ <A ′.
[3] The film-like fired material according to the above [1] or [2], wherein the sinterable metal particles are silver nanoparticles.
[4] A film with a support sheet provided with the film-like fired material according to any one of the above [1] to [3], and a support sheet provided on at least one side of the film-like fired material Firing material.
[5] The support sheet is provided with an adhesive layer on a base film,
The film-like fired material with a support sheet according to [4], wherein the film-like fired material is provided on the pressure-sensitive adhesive layer.

  According to the present invention, it is possible to provide a film-like fired material which is excellent in thickness stability and thermal conductivity, can be fired at low temperature, and exhibits excellent shear adhesion after firing. In addition, it is possible to provide a film-like fired material with a support sheet, which comprises the film-like fired material and is used for sinter bonding of a semiconductor element.

It is sectional drawing which shows typically a film-form baking material based on one Embodiment of this invention. It is sectional drawing which shows typically a mode estimated before baking of the film-form baking material based on one Embodiment of this invention. It is sectional drawing which shows typically the state by which the film-form baking material with a support sheet based on one Embodiment of this invention was stuck on the ring frame. It is sectional drawing which shows typically the state by which the film-form baking material with a support sheet based on one Embodiment of this invention was stuck on the ring frame. It is a perspective view which shows typically the state by which the film-form baking material with a support sheet based on one Embodiment of this invention was stuck on the ring frame. It is a graph of TG curve obtained by measurement. It is a graph of TG curve obtained by measurement. It is a graph of TG curve obtained by measurement. It is a graph of TG curve obtained by measurement.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate.
Note that the drawings used in the following description may be enlarged for convenience, in order to make the features of the present invention intelligible. Not necessarily.

«Film-like baking material»
The film-like fired material according to the embodiment is a film-like fired material containing sinterable metal particles and a binder component, and the heat measured from 40 ° C. to 600 ° C. at a temperature rising rate of 10 ° C./min. In the weight curve (TG curve), the temperature at which the negative slope is the largest is in the range of 200 ° C. to 350 ° C., and the weight residual rate (%) at 200 ° C. is the smallest at 200 ° C. to 350 ° C. It is characterized in that the value obtained by subtracting the weight remaining rate (%) is in the range of 5% to 20%.
FIG. 1: is sectional drawing which shows the film-form baking material of embodiment typically. The film-like fired material 1 contains sinterable metal particles 10 and a binder component 20.

The film-like fired material may be formed of one layer (single layer) or may be formed of two or more layers. When the film-like fired material comprises a plurality of layers, the plurality of layers may be identical to or different from each other, and the combination of the plurality of layers is not particularly limited as long as the effects of the present invention are not impaired.
In addition, in this specification, not only in the case of a film-like baking material, but “a plurality of layers may be the same as or different from each other” means “all layers may be the same or all layers”. Means that only some of the layers may be the same, and further, “a plurality of layers are different from each other” means “the constituent material of each layer, the composition ratio of the constituent materials, and the thickness Means that at least one of them is different from one another.

The thickness before firing of the film-like fired material is not particularly limited, but it is preferably 10 to 200 μm, preferably 20 to 150 μm, and more preferably 30 to 90 μm.
Here, "the thickness of the film-like fired material" means the thickness of the entire film-like fired material, and for example, the thickness of the film-like fired material consisting of a plurality of layers means all of the components of the film-like fired material. Means the total thickness of the layers.

  In the present specification, “thickness” can be obtained using a constant-pressure thickness measuring device according to JIS K7130 as a value represented by an average of thicknesses measured at any five places.

(Peeling film)
The film-like fired material can be provided in the state of being laminated on a release film. In use, the release film may be peeled off, and the film-like fired material may be placed on an object to be sintered and joined. The release film also has a function as a protective film for preventing damage and dirt adhesion of the film-like fired material. The release film may be provided on at least one side of the film-like fired material, and may be provided on both sides of the film-like fired material.

  As the release film, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, Polyurethane film, ethylene vinyl acetate copolymer film, ionomer resin film, ethylene (meth) acrylic acid copolymer film, ethylene (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluorine A transparent film such as a resin film is used. Moreover, these crosslinked films are also used. Furthermore, these laminated films may be sufficient. Also, a film colored with these, an opaque film, or the like can be used. As the release agent, for example, release agents such as silicone type, fluorine type, alkyd type, olefin type, long-chain alkyl group-containing carbamate and the like can be mentioned.

  The thickness of the release film is usually about 10 to 500 μm, preferably about 15 to 300 μm, and particularly preferably about 20 to 250 μm.

<Sinterable metal particles>
The sinterable metal particles are metal particles which can be melted and bonded together to form a sintered body by being subjected to heat treatment as firing of the film-like fired material. By forming the sintered body, it is possible to sinter and bond the film-like fired material and the article fired in contact therewith.

  Examples of metal species of the sinterable metal particles include silver, gold, copper, iron, nickel, aluminum, silicon, palladium, platinum, titanium, barium titanate, oxides or alloys thereof, silver and silver oxide Is preferred. Only one type of sinterable metal particles may be blended, or two or more types may be blended.

  The sinterable metal particles are preferably silver nanoparticles that are nano-sized silver particles.

The particle diameter of the sinterable metal particles contained in the film-like sintered material is not particularly limited as long as the sinterability can be exhibited, but may be 100 nm or less and 50 nm or less. It may well be 30 nm or less. In addition, with the particle diameter of the metal particle which a film-form baking material contains, let it be a projection area circle equivalent diameter of the particle diameter of the metal particle observed with the electron microscope. The metal particle which belongs to the range of the above-mentioned particle diameter is preferred because it excels in sinterability.
The particle diameter of the sinterable metal particles contained in the film-like sintered material is the number average of the particle diameters of particles having a projected area equivalent circle diameter of 100 nm or less of the particle diameters of metal particles observed by an electron microscope. , 0.1 to 95 nm, 0.3 to 50 nm, and 0.5 to 30 nm. The number of metal particles to be measured is at least 100 randomly selected per one film-like fired material.

  Before the sinterable metal particles are mixed with the binder component and the other additive components, they are previously dispersed in a high boiling point solvent such as isoboronyl hexanol or decyl alcohol so as to be in a state free of aggregates in advance. May be The boiling point of the high boiling point solvent may be, for example, 200 to 350 ° C. At this time, when a high boiling point solvent is used, the concentration of the sinterable metal particles is prevented from increasing because the solvent hardly volatilizes at normal temperature, and the workability is improved. Reaggregation etc. are also prevented, and it may become good in terms of quality. Dispersion methods include kneader, triple roll, bead mill and ultrasound.

  In addition to metal particles (sinterable metal particles) having a particle diameter of 100 nm or less, non-sinterable metal particles having a particle diameter exceeding 100 nm are further blended in the film-like fired material of the embodiment. It is also good. The particle size of the non-sinterable metal particle having a particle size of more than 100 nm is the number of the particle size of the particle size of the metal particle observed with an electron microscope determined for the particle having a projected area equivalent circle diameter of more than 100 nm. The average may be more than 150 nm and not more than 50000 nm, may be 150 to 10000 nm, and may be 180 to 5000 nm.

Examples of the metal species of the non-sinterable metal particles having a particle size of more than 100 nm include those exemplified above, and silver, copper, and their oxides are preferable.
The metal particles having a particle diameter of 100 nm or less and the non-sinterable metal particles having a particle diameter of more than 100 nm may be the same metal species or may be different metal species. For example, the metal particles having a particle diameter of 100 nm or less may be silver particles, and the non-sinterable metal particles having a particle diameter of more than 100 nm may be silver or silver oxide particles. For example, the metal particles having a particle diameter of 100 nm or less may be silver or silver oxide particles, and the non-sinterable metal particles having a particle diameter of more than 100 nm may be copper or copper oxide particles.

  In the film-like baked material of the embodiment, the content of the metal particles having a particle diameter of 100 nm or less may be 20 to 100 parts by mass, and 30 to 99 parts by mass with respect to 100 parts by mass of the total mass of all metal particles. It may be 50 to 95 parts by mass.

The surface of the sinterable metal particles and / or the non-sinterable metal particles may be coated with an organic matter. By having the coating of the organic substance, the compatibility with the binder component is improved, the aggregation of the particles can be prevented, and the particles can be dispersed uniformly.
When the surface of the sinterable metal particles and / or the non-sinterable metal particles is coated with an organic substance, the mass of the sinterable metal particles and the non-sinterable metal particles is the value including the coating and Do.

<Binder component>
By blending the binder component, the fired material can be formed into a film and adhesiveness can be imparted to the film-like fired material before firing. The binder component may be thermally decomposable by being heat-treated as firing of the film-like fired material.
Although a binder component is not specifically limited, Resin is mentioned as a suitable example of a binder component. Examples of the resin include acrylic resins, polycarbonate resins, polylactic acids, polymers of cellulose derivatives, and the like, with acrylic resins being preferred. Acrylic resins include homopolymers of (meth) acrylate compounds, copolymers of two or more of (meth) acrylate compounds, and copolymers of (meth) acrylate compounds and other copolymerizable monomers. included.

In the resin constituting the binder component, the content of the constituent unit derived from the (meth) acrylate compound is preferably 50 to 100% by mass, preferably 80 to 100% by mass, with respect to the total amount of the constituent units. More preferably, it is 90 to 100% by mass.
As used herein, "derived from" means that the structural change necessary for the monomer to undergo polymerization has been received.

Specific examples of the (meth) acrylate compound include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate and t-butyl (Meth) acrylate, pentyl (meth) acrylate, amyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (Meth) acrylate, ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, Decyl (meth) acrylate, alkyl (meth) acrylates such as lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate;
Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) Hydroxyalkyl (meth) acrylates such as acrylates;
Phenoxyalkyl (meth) acrylates such as phenoxyethyl (meth) acrylate and 2-hydroxy-3-phenoxypropyl (meth) acrylate; 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate and 2-propoxyethyl Alkoxyalkyl (meth) acrylates such as (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-methoxybutyl (meth) acrylate;
Polyethylene glycol mono (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, nonyl phenoxy polyethylene glycol (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxy polypropylene Polyalkylene glycol (meth) acrylates such as glycol (meth) acrylate, ethoxypolypropylene glycol (meth) acrylate, nonylphenoxypolypropylene glycol (meth) acrylate;
Cyclohexyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, bornyl (meth) acrylate, isobornyl ( Cycloalkyl (meth) acrylates such as meta) acrylates, tricyclodecanyl (meth) acrylates;
Mention may be made of benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate and the like. Alkyl (meth) acrylates or alkoxyalkyl (meth) acrylates are preferred, and butyl (meth) acrylate, ethylhexyl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, as a particularly preferable (meth) acrylate compound Mention may be made of ethyl hexyl (meth) acrylate and 2-ethoxyethyl (meth) acrylate.

In the present specification, “(meth) acrylate” is a concept including both “acrylate” and “methacrylate”.
As the acrylic resin, methacrylate is preferable. When the binder component contains a constitutional unit derived from methacrylate, the temperature with the largest negative slope in the thermal weight curve (TG curve) is in the range of 200 ° C. to 350 ° C., and the weight retention at 200 ° C. Value obtained by subtracting the smallest weight remaining rate (%) from 200% to 350 ° C from the rate (%) is in the range of 5% to 20%, and a film-like fired material is easily obtained .

  In the resin constituting the binder component, the content of the structural unit derived from methacrylate is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, with respect to the total amount of the structural units. It is further more preferable that it is 100 mass%.

  The other copolymerizable monomer is not particularly limited as long as it is a compound copolymerizable with the above (meth) acrylate compound, and examples thereof include (meth) acrylic acid, vinylbenzoic acid, maleic acid and vinylphthalic acid. Unsaturated carboxylic acids; vinyl group-containing radically polymerizable compounds such as vinylbenzyl methyl ether, vinyl glycidyl ether, styrene, α-methylstyrene, butadiene, isoprene and the like.

The weight average molecular weight (Mw) of the resin constituting the binder component is preferably 1,000 to 1,000,000, and more preferably 10,000 to 800,000. When the weight average molecular weight of the resin is in the above range, it becomes easy to express sufficient film strength as a film and to impart flexibility.
In addition, in this specification, a "weight average molecular weight" is a polystyrene conversion value measured by the gel permeation chromatography (GPC) method unless there is particular notice.

The glass transition temperature (Tg) of the resin constituting the binder component can be determined from the calculation using the theoretical formula of Fox described below, which is preferably −60 to 50 ° C., and is −30 to 10 ° C. It is more preferable that the temperature is -20 or more and less than 0 ° C. When the Tg determined from the Fox equation of the resin is equal to or less than the above upper limit, the adhesion between the film-like fired material and the adherend (eg, a chip, a substrate, etc.) before firing is improved. On the other hand, when the Tg of the resin determined from the Fox equation is not less than the above lower limit, the film shape can be maintained, and the separation of the film-like fired material from the support sheet and the like becomes easier.
The Tg of the acrylic polymer is determined according to the Fox equation from the weight ratio of the monomers of each polymer portion,
1 / Tg = (W1 / Tg1) + (W2 / Tg2) +... + (Wm / Tgm)
W1 + W2 + ... + Wm = 1
Show the relationship between In the formula, Tg represents the glass transition temperature of the polymer portion, and Tg1, Tg2, ..., Tgm represent the glass transition temperatures of the respective polymerization monomers. Further, W1, W2, ..., Wm represent weight ratios of respective polymerization monomers.
As the glass transition temperature of each polymerization monomer in the above-mentioned Fox formula, the values described in Polymer Data Handbook and Adhesion Handbook can be used.

The binder component may be thermally decomposable by being heat-treated as firing of the film-like fired material. The thermal decomposition of the binder component can be confirmed by the decrease in mass of the binder component by firing. In addition, although the component mix | blended as a binder component may be substantially thermally decomposed by baking, the total mass of the component mix | blended as a binder component does not need to be thermally decomposed by baking.
The binder component may be one whose mass after firing is 10% by mass or less, and may be 5% by mass or less, with respect to 100% by mass of the binder component before calcination, and 3% by mass or less It may be

  In the film-like fired material of the embodiment, in addition to the sinterable metal particles, the non-sinterable metal particles and the binder component described above, the sinterable metal particles and the non-sintered material can be used as long as the effects of the present invention are not impaired It may contain binding metal particles and other additives that do not correspond to the binder component.

  Other additives that may be contained in the film-like fired material of the embodiment include solvents, dispersants, plasticizers, tackifiers, storage stabilizers, antifoaming agents, thermal decomposition accelerators, antioxidants, etc. Can be mentioned. The additives may be contained alone or in combination of two or more. These additives are not particularly limited, and those commonly used in this field can be appropriately selected.

<Composition>
The film-like fired material of the embodiment may be composed of sinterable metal particles, a binder component, and other additives, and the sum of these contents (% by mass) may be 100% by mass. .
When the film-like fired material of the embodiment contains non-sinterable metal particles, the film-like fired material comprises sinterable metal particles, non-sinterable metal particles, a binder component, and other additives. The sum of these contents (% by mass) may be 100% by mass.

In the film-like fired material, the content of the sinterable metal particles is preferably 10 to 98% by mass with respect to 100% by mass of the total content of all components other than the solvent (hereinafter referred to as "solid content") 15-90 mass% is more preferable, and 20-80 mass% is further more preferable.
When the film-like sintered material contains non-sinterable metal particles, the total content of sinterable metal particles and non-sinterable metal particles is 100% by mass of the total solid content in the film-like sintered material 50-98 mass% is preferable, 70-95 mass% is more preferable, and 80-90 mass% is more preferable.

  2-50 mass% is preferable, as for content of the binder component with respect to 100 mass% of total content of solid content in a film-form baking material, 5-30 mass% is more preferable, and 10-20 mass% is more preferable.

  In the film-like fired material, the mass ratio of the sinterable metal particles to the binder component (sinterable metal particles: binder component) is preferably 50: 1 to 1: 5, and more preferably 20: 1 to 1: 2. 10: 1 to 1: 1 are more preferred. When the film-like fired material contains nonsinterable metal particles, the mass ratio of the sinterable metal particles and the nonsinterable metal particles to the binder component ((sinterable metal particles + nonsinterability 50: 1 to 1: 1 are preferable, 20: 1 to 2: 1 are more preferable, and 9: 1 to 4: 1 are further preferable.

  When the film-like fired material has the composition described above, the temperature with the largest negative slope in the thermal weight curve (TG curve) is in the range of 200 ° C. to 350 ° C., and the weight remaining at 200 ° C. It is easy to obtain a film-like fired material in which the value obtained by subtracting the smallest weight residual ratio (%) from 200% to 350 ° C from the ratio (%) is in the range of 5% to 20%.

  The film-like fired material may contain a high boiling point solvent used when mixing sinterable metal particles, non-sinterable metal particles, a binder component and other additive components. 20 mass% or less is preferable, as for content of the high boiling-point solvent with respect to 100 mass% of total mass of a film-form baking material, 15 mass% or less is more preferable, and 10 mass% or less is more preferable. By the content of the high boiling point solvent being below the above upper limit value, the temperature with the largest negative slope is in the range of 200 ° C. to 350 ° C. in the thermogravimetric curve (TG curve), and at 200 ° C. It is easy to obtain a film-like fired material in which the value obtained by subtracting the smallest weight remaining rate (%) at 200 ° C. to 350 ° C. from the weight remaining rate (%) of is within the range of 5% to 20%.

<Remaining percentage of weight in thermogravimetric curve (TG curve) (%)>
The film-like fired material of the embodiment has a temperature at which the negative slope is largest at 200 ° C. in a thermal weight curve (TG curve) measured from 40 ° C. to 600 ° C. at a temperature rising rate of 10 ° C./min. The value obtained by subtracting the smallest weight remaining rate (%) from 200 ° C. to 350 ° C. from the weight remaining rate (%) in the range of 350 ° C. and at 200 ° C. is in the range of 5% to 20%. It is characterized by being inside.

  The said TG curve represents the weight change of a film-form baking material in the process in which a film-form baking material is heat-processed.

  Hereinafter, the appearance of the film-like fired material in the firing process, which is estimated from the TG curve, will be described with reference to the drawings as appropriate.

FIG. 2 shows that the temperature with the largest negative slope in the thermal weight curve (TG curve) is in the range of 200 ° C. to 350 ° C., and the weight remaining rate (%) at 200 ° C. The value obtained by subtracting the smallest weight remaining rate (%) up to ° C. is within the range of 5% to 20%, before firing (FIG. 2 (a)) of the film-like fired material 1, firing It is sectional drawing which shows typically a mode estimated about inside (FIG. 2 (b)) and baking (FIG. 2 (c)).
The weight of the low-temperature decomposable binder component 20 contained in the film-like fired material (FIG. 2 (a)) before firing decreases by heating at 200 ° C. to 350 ° C. (FIG. 2 (b) to (c) ), This phenomenon appears as a negative slope in the TG curve.
The low-temperature decomposable binder component 20 contained in the film-shaped fired material (FIG. 2 (a)) before firing is thermally decomposed by absorbing heat when heated at 200 ° C. to 350 ° C. The sinterable metal particles 10 contained in FIG. 2 (a) are melted by absorbing heat when heated at 200 ° C. to 350 ° C. (FIG. 2 (b)) and then sintered while generating heat (FIG. 2) (C)).

  In the thermogravimetric curve (TG curve), the temperature at which the negative slope is the largest is in the range of 200 ° C. to 350 ° C., and the weight residual rate (%) at 200 ° C. The fact that the value obtained by subtracting the small weight residual rate (%) is in the range of 5% to 20% means that the solvent-derived component remaining in the paste or film is thermally decomposed at a heating temperature up to 200 ° C. The low temperature degradable binder component is considered to mean that the content is in the range of 5% to 20%. The reduction of TG at heating temperatures above 350 ° C. is presumed to be a high temperature degradable binder component. Therefore, in the thermogravimetric curve (TG curve), the temperature at which the negative slope is the largest is within the range of 200 ° C. to 350 ° C., and from the weight remaining rate (%) at 200 ° C., from 200 ° C. to 350 ° C. The film-like fired material 1 having a value obtained by subtracting the smallest weight remaining rate (%) in the range from 5% to 20% is a low temperature decomposable binder component which thermally decomposes at a temperature in the range of 200 ° C to 350 ° C. However, since it contains 5% to 20%, it can be sintered at a temperature in the range of 200 ° C. to 350 ° C. In addition, aggregation or fusion of the sinterable metal particles is not confirmed at the start stage of sintering, and it is presumed that the sinterable metal particles 10m melted as fine particles are sintered.

In the thermogravimetric curve (TG curve) measured from 40 ° C. to 600 ° C. at a heating rate of 10 ° C./min in the atmosphere, a film-like fired material having a temperature at which the negative slope is the largest is lower than 200 ° C. At the initiation stage of sintering, melting and sintering of the sinterable metal particles occur sequentially, and the particle size increases and lumps because the binder component is absent or is present in a small amount even if it is present. It is considered that voids tend to be generated, and sufficient shear adhesion can not be obtained.
In a thermogravimetric curve (TG curve) measured from 40 ° C. to 600 ° C. at a temperature rising rate of 10 ° C./min in the atmosphere, a film-like fired material having a temperature at which the negative slope is largest is higher than 350 ° C. Since the degradable binder component is contained in a larger amount than the low temperature degradable binder component, sufficient shear adhesion can not be obtained unless the baking is performed at a temperature higher than 350 ° C., but the sintering at a high temperature is And workpieces (semiconductor wafers etc.) such as semiconductors may be affected by high temperature.

In the thermogravimetric curve (TG curve) measured from 40 ° C. to 600 ° C. at a heating rate of 10 ° C./min in the atmosphere, the temperature with the largest negative slope is within the range of 200 ° C. to 350 ° C. Even if the film residual material (%) at 200 ° C minus the smallest weight residual ratio (%) from 200 ° C to 350 ° C is less than 5%, the film-like fired material has low temperature decomposability The absence of the binder component or the presence, if any, of a small amount makes it difficult to form a film. In this case, if high temperature decomposable binder components are contained, sufficient shear adhesion can be obtained by sintering at high temperature, but it is necessary to bake at high temperature, so the work (semiconductor wafer etc.) is high temperature There is a risk of being affected.
In the thermogravimetric curve (TG curve) measured from 40 ° C. to 600 ° C. at a heating rate of 10 ° C./min in the atmosphere, the temperature with the largest negative slope is within the range of 200 ° C. to 350 ° C. Even if the film-like fired material has a value obtained by subtracting the smallest weight remaining rate (%) from 200 ° C. to 350 ° C. from the weight remaining rate (%) at 200 ° C., it is after sintering As a result of the reduction of the bonding metal component of the above, the shear adhesion is reduced, and in order to obtain a sufficient shear adhesion, it is necessary to increase the thickness of the film.

  The shear adhesion of the film-like fired material after firing can be measured by the method described in the examples.

<Temperature (A ') / Temperature (B')>
The film-like fired material according to the embodiment is a thermogravimetric curve (TG curve) measured at a temperature rising rate of 10 ° C./min in the atmosphere for the component obtained by removing the sinterable metal particles from the film-like fired material. Differential thermal analysis curve (DTA curve) measured at a temperature (A ′) at which the negative slope is the largest and a temperature rise rate of 10 ° C./min in the atmosphere using alumina particles as a reference sample for the sinterable metal particles Among the peaks observed in the temperature range of 200 ° C. to 400 ° C., it is preferable that the peak temperature (B ′) observed at the lowest temperature satisfies the relationship of B ′ <A ′.

The TG curve represents a change in weight of components obtained by removing the sinterable metal particles from the film-like fired material in the process of being heat-treated as firing.
The DTA curve represents the temperature change of the differential heat of the sinterable metal particles in the process of being heat-treated as firing.

  The film-like fired material of the embodiment in which the film-like fired material of the embodiment includes non-sinterable metal particles is obtained by removing the sinterable metal particles and the non-sinterable metal particles from the film-like fired material With respect to the components, the temperature (A ′) at which the negative slope is the largest in a thermal weight curve (TG curve) measured at a temperature rising rate of 10 ° C./min in the atmosphere, the sinterable metal particles and the non-sintered Peak observed in a temperature range of 200 ° C. to 400 ° C. in a differential thermal analysis curve (DTA curve) measured at a temperature rising rate of 10 ° C./min in an air atmosphere using alumina particles as a reference sample Among them, it is preferable that the peak temperature (B ′) observed at the lowest temperature satisfy the relationship of B ′ <A ′.

Components obtained by removing the sinterable metal particles and the non-sinterable metal particles from the film-like fired material containing the binder component contained in the film-like fired material before firing decrease in weight by heating, This phenomenon appears as a negative slope in the TG curve.
The sinterable metal particles contained in the film-like fired material before firing cause melting and sintering when heated, the melting phenomenon appears as a negative peak in the DTA curve, and the sintering phenomenon appears as a positive peak in the DTA curve .

  The fact that the temperature (A ′) and the temperature (B ′) satisfy the relationship B ′ <A ′ means that the components distributed around the sinterable metal particles of the film-like fired material in the process of being heat-treated It is considered to mean that melting and sintering of the sinterable metal particles are started earlier compared to the timing of weight loss. Therefore, the film-like fired material satisfying the relationship of B '<A' is in a state in which each is isolated by the components distributed around the sinterable metal particles, and it is easy to melt in the form of fine particles, temperature (A ') The frequency of these collisions rapidly increases when reaching the point, and the sinterable metal particles melted as fine particles tend to be sintered. As a result, in the film-like fired material satisfying the relationship of B '<A', the sinterable metals are uniformly and tightly metal-bonded to each other, and it is considered that the strength of the material after sintering is improved.

The temperature (A ') and the temperature (B') separate the sinterable metal particles and the components other than the sinterable metal particles from the film-like fired material before firing, It can be determined from the TG curve and DTA curve for the sample.
The separation of the sinterable metal particles from the film-like fired material before firing and the remaining components other than the sinterable metal particles can be performed, for example, by the following method.
First, after mixing a film-like fired material before firing and a sufficient amount of organic solvent, the mixture is allowed to stand for a sufficient time until the sinterable metal particles settle. The supernatant is drawn out with a syringe or the like, and the residue after drying at 120 ° C. for 10 minutes is recovered, whereby the component obtained by removing the sinterable metal particles from the film-like fired material can be separated. Further, after a sufficient amount of the organic solvent is mixed again with the liquid containing the sinterable metal particles after removing the supernatant liquid with the above-mentioned syringe etc., it is sufficient for the sinterable metal particles to settle, Let stand and extract the supernatant with a syringe or the like. After repeating mixing and standing of the organic solvent and extraction of the supernatant five times or more, the sinterable metal particles are separated by collecting the residue after drying the remaining solution at 120 ° C. for 10 minutes. It is possible.

The same applies to the case where the film-like fired material of the embodiment contains non-sinterable metal particles, and the temperature (A ') and the temperature (B') are obtained by firing the film-like fired material before firing. TG curve and DTA curve for each sample separated by separating the sinterable metal particles and the non-sinterable metal particles from the components excluding the sinterable metal particles and the non-sinterable metal particles It can be obtained from
Separation of the sinterable metal particles and the non-sinterable metal particles from the film-like fired material before firing and the remaining components other than the sinterable metal particles and the non-sinterable metal particles is, for example, , Can be performed by the following method.
First, after mixing the film-like fired material before firing and a sufficient amount of organic solvent, the mixture is allowed to stand for a sufficient time until the sinterable metal particles and the non-sinterable metal particles settle. The supernatant is drawn out with a syringe or the like, and the residue after drying at 120 ° C. for 10 minutes is recovered, thereby removing the components from which the sinterable metal particles and the non-sinterable metal particles have been removed from the film-like fired material. It can be divided. Further, after a sufficient amount of the organic solvent is mixed again with the liquid containing the sinterable metal particles and the non-sinterable metal particles after removing the supernatant liquid with the above-mentioned syringe or the like, the sinterable metal particles are sinterable The mixture is allowed to stand for a sufficient time until the non-sinterable metal particles settle, and the supernatant is drawn out with a syringe or the like. After repeating mixing and standing of the organic solvent and extraction of the supernatant five times or more, the sinterable metal particles and the non-sintered metal are recovered by collecting the residue after drying the remaining liquid at 120 ° C. for 10 minutes. It is possible to separate binding metal particles.

  The solvent used here is preferably one which can dissolve the binder component and can be volatilized under the above-mentioned drying conditions of 120 to 250 ° C. for 10 minutes, and depending on the kind of the binder component, the preferable one is appropriately selected. It can be used. For example, hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol) and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone Ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide, N-methylpyrrolidone and the like.

«Method for producing film-like fired material»
A film-like fired material can be formed using a fired material composition containing the constituent material. For example, by applying a baking material composition containing each of the components for forming the film-like baking material and a solvent on a surface to be formed of the film-like baking material, and drying it as necessary to volatilize the solvent, A film adhesive can be formed at a target site.
As the solvent, those having a boiling point of less than 250 ° C. are preferable, and, for example, n-hexane (boiling point: 68 ° C.), ethyl acetate (boiling point: 77 ° C.), 2-butanone (boiling point: 80 ° C.), n-heptane (boiling point: 98 ° C), methylcyclohexane (boiling point: 101 ° C), toluene (boiling point: 111 ° C), acetylacetone (boiling point: 138 ° C), n-xylene (boiling point: 139 ° C), dimethylformamide (boiling point: 153 ° C) and butyl carbibi Toll (boiling point: 230 ° C.) and the like can be mentioned. These may be used alone or in combination.

  As a formation object surface of a film-form baking material, the surface of a peeling film is mentioned.

  Coating of the fired material composition may be performed by a known method, for example, an air knife coater, a blade coater, a bar coater, a gravure coater, a comma coater, a roll coater, a roll knife coater, a curtain coater, a die coater, a knife coater And methods using various coaters such as a screen coater, a Mayer bar coater, and a kiss coater.

  The drying conditions of the fired material composition are not particularly limited, but when the fired material composition contains a solvent, it is preferable to heat and dry, in which case, for example, at 70 to 250 ° C., for example 80 to 180 ° C. It is preferable to dry under the conditions of 10 seconds to 10 minutes.

«Film-like baking material with support sheet»
The film-like fired material with support sheet of the embodiment includes the film-like fired material of the embodiment and a support sheet provided on at least one side of the film-like fired material. The support sheet is preferably provided with a pressure-sensitive adhesive layer on the entire surface or the outer peripheral portion of the base film, and the film-like baking material is preferably provided on the pressure-sensitive adhesive layer. The film-like fired material may be provided in direct contact with the pressure-sensitive adhesive layer, or may be provided in direct contact with the base film. By taking this form, it can be used as a dicing sheet used when singulating a semiconductor wafer into elements. In addition, by using a blade or the like to separate it together with the wafer, it can be processed as a film-like fired material having the same shape as the device, and a semiconductor device with a film-like fired material can be manufactured.

  Hereinafter, an embodiment of a film-like baking material with a support sheet will be described. The schematic sectional drawing of the film-form baking material with a support sheet of embodiment is shown to FIG. 3 and FIG. As shown in FIG. 3 and FIG. 4, the film-like fired material 100a, 100b with support sheet of the embodiment is such that the film-like fired material 1 can be peeled off on the inner periphery of the support sheet 2 having the adhesive part at the outer periphery. It is temporarily attached. The support sheet 2 is a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer 4 on the upper surface of a base film 3 as shown in FIG. 3, and the inner peripheral surface of the pressure-sensitive adhesive layer 4 is covered with a film-like baking material The adhesive portion is exposed at the outer peripheral portion. Further, as shown in FIG. 4, the support sheet 2 may have a ring-shaped pressure-sensitive adhesive layer 4 at the outer peripheral portion of the base film 3.

  The film-like fired material 1 is formed on the inner circumferential portion of the support sheet 2 in substantially the same shape as the work (semiconductor wafer or the like) to be attached. An adhesive portion is provided on the outer periphery of the support sheet 2. In a preferred embodiment, the film-like fired material 1 having a diameter smaller than that of the support sheet 2 is concentrically stacked on the circular support sheet 2. The adhesive part of the outer peripheral part is used for fixing the ring frame 5 as illustrated.

(Base film)
The base film 3 is not particularly limited. For example, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), ethylene / propylene copolymer, polypropylene, polybutene, polybutadiene, polymethylpentene, ethylene / vinyl acetate Copolymer, ethylene, (meth) acrylic acid copolymer, ethylene, methyl (meth) acrylate copolymer, ethylene, ethyl (meth) acrylate copolymer, polyvinyl chloride, vinyl chloride, vinyl acetate copolymer A film made of coalesced, polyurethane film, ionomer or the like is used. In the present specification, “(meth) acrylic” is used to mean that it includes both acrylic and methacrylic.
When higher heat resistance is required for the support sheet, polyester film such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc., polyolefin film such as polypropylene, polymethylpentene etc. can be used as the base film 3 It can be mentioned. In addition, these cross-linked films and modified films by radiation, discharge and the like can also be used. The base film may be a laminate of the above films.

  Moreover, these films can also be used in lamination of 2 or more types, or in combination. Further, those obtained by coloring these films or those obtained by printing can also be used. In addition, the film may be a sheet formed of a thermoplastic resin by extrusion or may be stretched, and a sheet obtained by thinning and curing a curable resin by a predetermined means is used. It may be

  The thickness of the substrate film is not particularly limited, and is preferably 30 to 300 μm, more preferably 50 to 200 μm. By setting the thickness of the substrate film in the above range, breakage of the substrate film is unlikely to occur even if cutting is performed by dicing. Moreover, since sufficient flexibility is given to the film-like baking material with a support sheet, it shows favorable sticking property with respect to a workpiece | work (for example, semiconductor wafer etc.).

  The base film can also be obtained by applying a release agent to the surface and performing a release treatment. Alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, wax-based, etc. are used as the release agent used for the release treatment, but particularly the alkyd-based, silicone-based and fluorine-based release agents are heat resistant It is preferable because it has

  In order to release the surface of the substrate film using the above release agent, the release agent may be used as a solventless or solvent diluted or emulsified to form a gravure coater, a Mayer bar coater, an air knife coater, a roll coater, etc. The base film to which the release agent has been applied is applied at room temperature or under heating, or cured by electron beam, wet lamination or dry lamination, hot melt lamination, melt extrusion lamination, coextrusion processing, etc. The stack may be formed by

(Pressure-sensitive adhesive layer)
The support sheet 2 has an adhesive portion at least at its outer peripheral portion. The adhesive portion preferably has a function of temporarily fixing the ring frame 5 at the outer peripheral portion of the film-like sintered material 100a, 100b with the support sheet, and the ring frame 5 is preferably removable after a required process. Therefore, as the pressure-sensitive adhesive layer 4, one having a weak adhesiveness may be used, or one having an energy ray curing property in which the adhesive force is reduced by the energy ray irradiation may be used. The releasable pressure-sensitive adhesive layer is a conventionally known various pressure-sensitive adhesive (for example, general-purpose pressure-sensitive adhesives such as rubber-based, acrylic-based, silicone-based, urethane-based and vinyl ether-based, pressure-sensitive adhesives with surface irregularities, energy ray-curable A pressure-sensitive adhesive, a thermal expansion component-containing pressure-sensitive adhesive, etc.) can be used.

  In the configuration shown in FIG. 4, a ring-shaped pressure-sensitive adhesive layer 4 is formed on the outer peripheral portion of the base film 3 to form a pressure-sensitive adhesive portion. At this time, the pressure-sensitive adhesive layer 4 may be a single-layer pressure-sensitive adhesive layer comprising the above-mentioned pressure-sensitive adhesive, or a double-sided pressure-sensitive adhesive tape comprising the pressure-sensitive adhesive layer comprising the above-mentioned pressure-sensitive adhesive.

  Further, as shown in FIG. 3, the support sheet 2 is a pressure-sensitive adhesive sheet having a normal configuration having the pressure-sensitive adhesive layer 4 on the entire upper surface of the base film 3, and the inner peripheral surface of the pressure-sensitive adhesive layer 4 is a film. The adhesive part may be exposed to the outer peripheral part by being covered with the sintering material. In this case, the outer peripheral portion of the pressure-sensitive adhesive layer 4 is used to fix the ring frame 5 described above, and the film-like baking material is laminated on the inner peripheral portion so as to be peelable. As the pressure-sensitive adhesive layer 4, as described above, a weak adhesive may be used, or an energy ray-curable pressure-sensitive adhesive may be used.

  As a weak adhesive, an acrylic type and a silicone type are preferably used. Also, in consideration of the releasability of the film-like fired material, the adhesive strength of the pressure-sensitive adhesive layer 4 to the SUS plate at 23 ° C. is preferably 30 to 120 mN / 25 mm, and 50 to 100 mN / 25 mm. Is more preferable, and 60 to 90 mN / 25 mm is more preferable. If this adhesive strength is too low, the adhesion between the film-like baked material 1 and the pressure-sensitive adhesive layer 4 will be insufficient, the film-like baked material and the pressure-sensitive adhesive layer may peel off in the dicing step, and the ring frame may fall off. There is something to do. When the adhesive strength is too high, the film-like baked material and the pressure-sensitive adhesive layer adhere excessively to cause a pickup failure.

  In the case of using the energy ray-curable removable pressure-sensitive adhesive layer in the support sheet having the configuration shown in FIG. 3, the area to which the film-like fired material is laminated is irradiated with energy rays in advance to reduce adhesion. Good. At this time, other regions may not be irradiated with energy rays, and for example, the adhesion may be kept high for the purpose of adhesion to the ring frame 5. To prevent energy beam irradiation only in other regions, for example, an energy beam shielding layer is provided in a region corresponding to the other region of the substrate film by printing or the like, and energy beam radiation is applied from the substrate film side. It is good. Moreover, in the support sheet of the structure of FIG. 4, in order to strengthen adhesion | attachment of the base film 3 and the adhesive layer 4, in the surface in which the adhesive layer 4 of the base film 3 is provided, sandblast or Irregularization treatment by solvent treatment or the like, or oxidation treatment such as corona discharge treatment, electron beam irradiation, plasma treatment, ozone / ultraviolet radiation treatment, flame treatment, chromic acid treatment, hot air treatment and the like can be applied. Also, primer treatment can be performed.

  The thickness of the pressure-sensitive adhesive layer 4 is not particularly limited, but is preferably 1 to 100 μm, more preferably 2 to 80 μm, and particularly preferably 3 to 50 μm.

(Film-like firing material with support sheet)
The film-like fired material with support sheet is temporarily attached to the inner periphery of the support sheet having the adhesive part at the outer periphery so as to be peelable. In the configuration example shown in FIG. 3, the film-like fired material 1 is laminated on the inner peripheral portion of the support sheet 2 composed of the base film 3 and the pressure-sensitive adhesive layer 4 so as to be peelable. The adhesive layer 4 is exposed at the outer peripheral portion of the support sheet 2. In this configuration example, it is preferable that the film-like fired material 1 having a diameter smaller than that of the support sheet 2 be concentrically and releasably laminated on the pressure-sensitive adhesive layer 4 of the support sheet 2.

  The film-like fired material 100 a with a support sheet of the above configuration is attached to the ring frame 5 in the pressure-sensitive adhesive layer 4 exposed to the outer peripheral portion of the support sheet 2.

  In addition, an annular double-sided tape or pressure-sensitive adhesive layer may be additionally provided on the adhesive margin (exposed pressure-sensitive adhesive layer at the outer peripheral portion of the pressure-sensitive adhesive sheet) to the ring frame. The double-sided tape has a constitution of pressure-sensitive adhesive layer / core material / pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer in the double-sided tape is not particularly limited. For example, a pressure-sensitive adhesive such as rubber, acrylic, silicone, polyvinyl ether is used . The pressure-sensitive adhesive layer is attached to the ring frame at the outer peripheral portion when the element described later is manufactured. As a core material of a double-sided tape, a polyester film, a polypropylene film, a polycarbonate film, a polyimide film, a fluorine resin film, a liquid crystal polymer film etc. are used preferably, for example.

  In the structural example shown in FIG. 4, the ring-shaped adhesive layer 4 is formed in the outer peripheral part of the base film 3, and it is set as the adhesion part. In FIG. 5, the perspective view of the film-form baking material 100b with a support sheet shown in FIG. 4 is shown. At this time, the pressure-sensitive adhesive layer 4 may be a single-layer pressure-sensitive adhesive layer comprising the above-mentioned pressure-sensitive adhesive, or a double-sided pressure-sensitive adhesive tape comprising the pressure-sensitive adhesive layer comprising the above-mentioned pressure-sensitive adhesive. The film-like baking material 1 is peelably laminated on the inner peripheral portion of the base film 3 surrounded by the adhesive portion. In this configuration example, it is preferable that the film-like fired material 1 having a diameter smaller than that of the support sheet 2 be concentrically and releasably laminated on the base film 3 of the support sheet 2.

  In the film-like baked material with a support sheet, a release film for the purpose of surface protection for avoiding contact with the outside of the surface of one or both of the film-like baked material and the adhesive part until being provided for use. May be provided.

  The surface protection film (release film) may also be obtained by applying a release agent to the surface of a base film such as polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and polypropylene mentioned above and subjecting the film to release treatment. it can. Alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, wax-based, etc. are used as the release agent used for the release treatment, but particularly the alkyd-based, silicone-based and fluorine-based release agents are heat resistant It is preferable because it has

  In order to release the surface of the substrate film using the above release agent, the release agent may be used as a solventless or solvent diluted or emulsified to form a gravure coater, a Mayer bar coater, an air knife coater, a roll coater, etc. The base film to which the release agent has been applied is applied at room temperature or under heating, or cured by electron beam, wet lamination or dry lamination, hot melt lamination, melt extrusion lamination, coextrusion processing, etc. The stack may be formed by

  1 to 500 μm is preferable, 5 to 300 μm is more preferable, and 10 to 150 μm is more preferable.

«Method for producing film-like fired material with support sheet»
The film-like fired material with a support sheet can be manufactured by sequentially laminating the above-mentioned layers so as to have a corresponding positional relationship.
For example, when laminating a pressure-sensitive adhesive layer or a film-like baking material on a substrate film, a pressure-sensitive adhesive composition or a baking material composition containing a component for constituting the pressure-sensitive adhesive film or a solvent is coated on a release film. The pressure-sensitive adhesive layer or the film-like baking material is formed in advance on the release film by drying and volatilizing the solvent to form a film, if necessary. The exposed surface of the firing material opposite to the side in contact with the release film may be attached to the surface of the base film. At this time, the pressure-sensitive adhesive composition or the baking material composition is preferably applied to the release-treated surface of the release film. The release film may be removed as necessary after the formation of the laminated structure.

  For example, a film-like fired material with a support sheet in which a pressure-sensitive adhesive layer is laminated on a substrate film and a film-like fired material is laminated on the pressure-sensitive adhesive layer (a support sheet is a laminate of a substrate film and a pressure-sensitive adhesive layer) In the case of producing a film-like fired material with a support sheet, the pressure-sensitive adhesive layer is laminated on the base film by the above-mentioned method, and components for constituting the same separately on the release film and A baking material composition containing a solvent is applied, dried as necessary, and the solvent is evaporated to form a film, whereby a film-like baking material is formed on the release film, and this film-like baking material The film-like baking material with a support sheet is obtained by laminating the film-like baking material on a pressure-sensitive adhesive layer by laminating the exposed side of the above onto the exposed surface of the pressure-sensitive adhesive layer laminated on a substrate. Also when forming a film-like baking material on a peeling film, the baking material composition is preferably applied to the peeling treated surface of the peeling film, and the peeling film is removed if necessary after formation of a laminated structure. Good.

  As described above, any layers other than the base material constituting the film-like fired material with support sheet can be previously formed on the peelable film in advance and laminated on the surface of the target layer, so that it is necessary. Accordingly, a layer adopting such a process may be appropriately selected to produce a film-like fired material with a support sheet.

  In addition, after a film-like baking material with a support sheet provides all the required layers, it may be stored in the state in which the peeling film was bonded together on the surface of the outermost layer on the opposite side to the support sheet.

<< Method of Manufacturing Device >>
Next, a method of using the film-like fired material with a support sheet according to the present invention will be described by taking the case where the fired material is applied to the production of an element (for example, a semiconductor element) as an example.

  As one embodiment of the present invention, a method of manufacturing a semiconductor element using a film-like sintered material with a support sheet comprises peeling off a peel film of the film-like sintered material with a support sheet and forming a circuit on the surface (workpiece A film-like baking material with a support sheet may be attached to the back surface of), and the following steps (1) to (2) may be performed in the order of (1) and (2), and the following steps (1) to (4) may be performed in the order of (1), (2), (3), and (4).

Step (1): dicing the semiconductor wafer (work) and the film-like fired material of the laminate in which the support sheet, the film-like fired material and the semiconductor wafer (work) are stacked in this order;
Step (2): a step of peeling the film-like fired material and the support sheet to obtain an element with a film-like fired material,
Step (3): a step of attaching an element with a film-like fired material to the surface of an adherend,
Step (4): a step of firing the film-like firing material to bond the semiconductor element and the adherend.

Hereafter, the case where the said process (1)-(4) is performed is demonstrated.
The semiconductor wafer may be a silicon wafer and a silicon carbide wafer, or may be a compound semiconductor wafer such as gallium arsenide. The formation of the circuit on the wafer surface can be performed by various methods including conventionally used methods such as etching method and lift-off method. Next, the opposite surface (rear surface) of the circuit surface of the semiconductor wafer is ground. The grinding method is not particularly limited, and grinding may be performed by a known means using a grinder or the like. At the time of back grinding, an adhesive sheet called a surface protective sheet is attached to the circuit surface in order to protect the circuit on the surface. In the back surface grinding, the circuit surface side (that is, the surface protection sheet side) of the wafer is fixed by a chuck table or the like, and the back surface side on which the circuit is not formed is ground by the grinder. The thickness of the wafer after grinding is not particularly limited, but is usually about 20 to 500 μm. After that, if necessary, the fractured layer generated during back grinding is removed. The removal of the fractured layer is performed by chemical etching, plasma etching or the like.

  Subsequently, the film-form baking material of the said film-form baking material with a support sheet is stuck on the back surface of a semiconductor wafer. Thereafter, steps (1) to (4) are performed in the order of (1), (2), (3), and (4).

  The laminate of semiconductor wafer / film-like sintered material / support sheet is diced for each circuit formed on the wafer surface to obtain a laminate of semiconductor element / film-like sintered material / support sheet. The dicing is performed to cut the wafer and the film-like baking material together. According to the film-like sintered material with a support sheet of the embodiment, since the adhesive force is exhibited between the film-like sintered material and the support sheet at the time of dicing, chipping and element fly can be prevented, and the dicing ability is excellent. . Dicing is not particularly limited. For example, when dicing the wafer, the peripheral portion of the support sheet (peripheral portion of the support) is fixed by a ring frame, and then a known method such as using a rotating round blade such as dicing blade is used. A method of singulating the wafer may, for example, be mentioned. The cutting depth to the support sheet by dicing may be completely cut from the film-like fired material, and is preferably 0 to 30 μm from the interface between the film-like fired material and the support sheet. By reducing the cut amount to the support sheet, it is possible to suppress the melting of the pressure-sensitive adhesive layer and the base film constituting the support sheet due to the friction of the dicing blade, and the generation of burrs and the like.

  Thereafter, the support sheet may be expanded. When the base film of the support sheet is selected to be excellent in extensibility, the support sheet has excellent expandability. The film-like fired material and the support sheet are peeled off by picking up the diced semiconductor device with a film-like fired material by general means such as collet. As a result, a semiconductor element (a semiconductor element with a film-like fired material) having a film-like fired material on the back surface is obtained.

Subsequently, the attached element for a film-like firing material is attached to the surface of an adherend such as a substrate, a lead frame, or a heat sink.
Then, the film-like fired material is fired to sinter and bond an adherend such as a substrate, a lead frame, a heat sink and the like to the element. At this time, if the exposed surface of the film-like fired material of the semiconductor device with a film-like fired material is attached to an adherend such as a substrate, a lead frame and a heat sink, the semiconductor wafer (work) with the film-like fired material Sinter bonding can be performed with the adherend.

  Although the heating temperature which bakes a film-like baking material may be suitably determined in consideration of the kind of film-like baking material etc., 100-600 ° C is preferred, 150-550 ° C is more preferred, and 250-500 ° C is still more preferred. preferable. The heating time may be appropriately determined in consideration of the type of the film-like fired material and the like, but is preferably 1 to 60 minutes, more preferably 1 to 30 minutes, and still more preferably 1 to 10 minutes.

  The firing of the film-like firing material may be carried out by applying pressure to the film-like firing material to carry out pressure firing. The pressurizing condition can be, for example, about 1 to 50 MPa.

  According to the device manufacturing method of the embodiment, a film-like baked material having high uniformity of thickness can be easily formed on the back surface of the device, and cracks after the dicing step and packaging are less likely to occur. In addition, according to the device manufacturing method of the embodiment, it is possible to obtain a semiconductor device with a film-like fired material without individually attaching a film-like fired material to the back surface of the individualized semiconductor device, simplifying the manufacturing process. Can be Then, the semiconductor element with a film-like fired material is disposed on a desired adherend such as a device substrate and fired to sinter and bond the semiconductor element and the adherend via the film-like fired material. Semiconductor devices can be manufactured.

  As one embodiment, a semiconductor device with a film-like fired material provided with a semiconductor device and the film-like fired material of the embodiment is obtained. The semiconductor device with a film-like fired material can be manufactured, for example, by the above-described method of manufacturing a device.

  In the above embodiment, the sinter bonding of the semiconductor element of the film-like sintered material and the adherend thereof is exemplified, but the object of the sinter-joining of the film-like sintered material is not limited to those exemplified above, Sinter bonding is possible to various articles sintered in contact with the film-like fired material.

  Hereinafter, the present invention will be more specifically described by way of examples and the like, but the scope of the present invention is not limited to these examples and the like.

<Production of Firing Material Composition>
The components used for producing the fired material composition are shown below. Here, metal particles having a particle diameter of 100 nm or less are referred to as "sinterable metal particles", and metal particles having a particle diameter exceeding 100 nm are referred to as "non-sinterable metal particles".

(Sinterable metal particle inclusion paste material)
・ Alco nano silver paste ANP-1 (Organic coated composite silver nano paste, Applied Nanoparticles Research Institute, Inc .: Alcohol derivative coated silver particles, metal content 70 wt% or more, silver particles 60 wt% or less with an average particle size of 100 nm or less)
・ Alco nano silver paste ANP-4 (Organic coated composite silver nano paste, Applied nanoparticle research institute: Alcohol derivative coated silver particles, metal content 80 wt% or more, silver particles 25 wt% or more with an average particle size of 100 nm or less)

(Binder component)
Acrylic polymer 1 [2-ethylhexyl methacrylate polymer, average molecular weight 280,000, L-0818, manufactured by Japan Synthetic Chemical Co., MEK diluted product, solid content 54.5 mass%, Tg: −10 ° C. (Fox theory Calculated value using equation)]
Acrylic polymer 2 [methyl acrylate / 2-hydroxy acrylate copolymer, copolymer weight ratio 85/15, average molecular weight 370,000, N-4617, manufactured by Japan Synthetic Chemical Co., ethyl acetate / toluene = 1/1 Mixed solvent diluted product, solid content 35.7% by mass, Tg: 4 ° C. (calculated value using theoretical formula of Fox)

  Each component was mixed by the mixing | blending shown to following Table 1, and the baking material composition corresponding to Example 1-2 and Comparative Examples 1-2 was obtained. The values of the respective components in Table 1 represent parts by mass. Since the sinterable metal particle-containing paste material is sold with a high boiling point solvent and remains in the material for film-like firing after coating or drying, the components of the sinterable metal particle-containing paste material Has included them. The solvent in the binder component represents the solid part by mass excluding the solvent component in consideration of volatilization during drying.

<Production of film-like fired material>
The baked material composition obtained above is coated on one surface of a release film (thickness 38 μm, SP-PET 381031, manufactured by Lintec Corporation) and dried at 110 ° C. for 4 minutes to have the thickness shown in Table 1. A film-like fired material was obtained.

<Method of separating sinterable metal particles and non-sinterable metal particles from film-like fired material and components other than these>
After mixing the film-like fired material before firing and about 10 times by weight of the organic solvent, it was allowed to stand for about 30 minutes until the sinterable metal particles and the non-sinterable metal particles were settled. . The supernatant is drained with a syringe, and the residue after drying at 120 ° C. for 10 minutes is recovered to separate the components obtained by removing the sinterable metal particles and the non-sinterable metal particles from the film-like fired material. did. In addition, after mixing about 10 times the amount of the organic solvent of the film-like fired material with the liquid containing the sinterable metal particles and the non-sinterable metal particles after removing the supernatant liquid with the above-mentioned syringe again. The mixture was allowed to stand for about 30 minutes until the sinterable metal particles and the non-sinterable metal particles settled, and the supernatant was withdrawn with a syringe. After repeating mixing and standing of the organic solvent and extraction of the supernatant five times, the remaining liquid is dried at 120 ° C. for 10 minutes and then the residue is recovered to obtain sinterable metal particles and non-sintering. Metal particles were separated.

<Evaluation of film-like fired material>
The following items were evaluated about the film-like baking material obtained above.

(Measurement of TG / DTA)
About the film-like baked material obtained above, using a thermal analysis measurement device (Thermal analyzer TG / DTA simultaneous measurement device DTG-60, manufactured by Shimadzu Corporation), the same amount of alumina particles as the measurement sample is used as a reference sample The temperature was measured from 40.degree. C. to 600.degree. C. at a heating rate of 10.degree. C./min. The result of Examples 1-2 is shown to FIGS. 6-7, and the result of Comparative Examples 1-2 is shown to FIGS. 8-9. In addition, the temperature (A) [° C] at which the negative slope is the largest in the TG curve, the weight remaining rate (C) [%] at 200 ° C, the temperature D at which the weight remaining rate becomes the smallest at 200 ° C to 350 ° C. A value obtained by subtracting the smallest weight residual rate (%) from 200 ° C. to 350 ° C. from [° C.] and the weight residual rate (E) [%] at that temperature and the weight residual rate (%) at 200 ° C. Is shown in Table 1.
In addition, the temperature (A ′) at which the negative slope is the largest in the TG curve, and the DTA for the components obtained by removing the sinterable metal particles and the non-sinterable metal particles from the film-like fired material by the separation method Among the peaks observed in the temperature range of 200 ° C. to 400 ° C. in the curve, the peak temperature (B ′) observed at the lowest temperature is shown in Table 1.

(Measurement of shear adhesion)
The shear adhesion after firing of the film-like fired material was measured by the following method.
The film-like fired material obtained above is cut into 10 mm × 10 mm and attached to the top surface of a cylindrical copper adherend with a height of 5 mm having a cross section of 10 mm in diameter, and 5 mm in diameter thereon A cylindrical copper adherend with a height of 2 mm and a cross section is placed and fired under the following conditions (1) to (3) in the air atmosphere to obtain a test piece for bonding adhesion measurement. The A force is applied from the shear direction at a speed of 6 mm / min to the adhesive surface of the test piece at room temperature to measure the strength when the adhesion state is broken, and the measurement results of the test piece obtained under the following pressure baking conditions Among them, the shear adhesive strength was taken as the average value of the values of the conditions showing the highest bonding strength. The results are shown in Table 1.
(1) 300 ° C. for 3 minutes, 30 MPa,
(2) 350 ° C. for 3 minutes, 10 MPa,
(3) 400 ° C 3 minutes, 10MPa

(Measurement of thickness)
According to JIS K7130, it measured using a constant pressure thickness measuring instrument (made by Techlock, product name "PG-02").

  The film-like fired material of Examples 1-2 had high shear adhesion as compared with the fired material of Comparative Examples 1-2.

  Each configuration in each embodiment and the combination thereof are one example, and addition, omission, substitution, and other modifications of the configuration are possible without departing from the spirit of the present invention. Moreover, this invention is not limited by each embodiment, It limits only by the range of a claim (claim).

DESCRIPTION OF SYMBOLS 1 ... Film-like baking material, 1c ... Firing material, 10, 11 ... Sinterable metal particle, 20, 21 ... Binder component, 100 ... Film-like baking material with a support sheet 2 ... Support sheet, 3 .. Base film, 4 ... adhesive layer, 5 ... ring frame

Claims (5)

A film-like fired material comprising sinterable metal particles and a binder component,
In the thermogravimetric curve (TG curve) measured from 40 ° C. to 600 ° C. at a heating rate of 10 ° C./min in the atmosphere, the temperature at which the negative slope is largest is in the range of 200 ° C. to 350 ° C. A film characterized in that the value obtained by subtracting the smallest weight remaining rate (%) from 200 ° C. to 350 ° C. from the weight remaining rate (%) at 200 ° C. is in the range of 5% to 20%. Firing material. Negative inclination in a thermogravimetric curve (TG curve) measured from 40 ° C. to 600 ° C. at a temperature rising rate of 10 ° C./min in the atmosphere for the component obtained by removing the sinterable metal particles from the film-like fired material The differential thermal analysis curve (DTA curve) measured at a heating rate of 40 ° C. to 600 ° C. at a temperature of 10 ° C./min in the atmosphere using alumina particles as a reference sample for the temperature (A ′) at which temperature is largest Peak temperature (B ') observed at the lowest temperature in
The film-like baked material according to claim 1, wherein B satisfies the relationship of B ′ <A ′.   The film-form baking material of Claim 1 or 2 whose said sinterable metal particle is a silver nanoparticle.   The film-like baking material with a support sheet provided with the film-like baking material as described in any one of Claims 1-3, and the support sheet provided in the at least one side of the said film-like baking material. The support sheet is provided with an adhesive layer on a base film,
The film-like baking material with a support sheet according to claim 4, wherein the film-like baking material is provided on the pressure-sensitive adhesive layer.

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