Thermally conductive polymers

Abstract

A polymer comprising a repeating unit of formula (I): [Case 1] TIFF2024500048000023.tif30144, wherein Ar, in each occurrence, is an arylene or heteroarylene group; p is at least 2; and Y 1 And one of Y2 is CR 1 and R 1 is H or a substituent, Y 1 and Y 2 The other is a polymer in which N is the other. The polymer can be formed by the reaction of monomers containing reactive groups that react to form imines. This polymer can be used as a thermally conductive polymer, for example, as a thermally conductive layer in an electronic device.

Description

[Background technology]

[0001] Thermally conductive materials are used in a wide variety of applications, including underfilling flip chips, to reduce thermally induced stress after flip chip application.

[0002] Mary Liu and Wusheng Yin, “A novel high thermal conductive underfill for flip chip application” (http: / / yincae.com / assets / wp-1000-03_2013.pdf) disclose an underfill containing diamond powder.

[0003] Islam et al, “Enhanced Thermal Conductivity of Liquid Crystalline Epoxy Resin using Controlled Linear Polymerization”, ACS Macro Lett. 2018, 7, 10, 1180-1185 disclose a liquid crystal epoxy resin having a two-dimensional boron nitride filler.

[0004] WO2019 / 143823 discloses a thermally conductive quinoid-type conjugated polymer thin film manufactured by oxidative chemical vapor deposition.

[0005] Huang et al, “Thermal conductivity of polymers and polymer nanocomposites”, Materials Science and Engineering: R: Reports, Vol. 132, October 2018, pp. 1-22, describes the heat transport mechanism in polymers.

[0006] Suematsu et al, “Polyimine, a C=N Double Bond Containing Polymers: Synthesis and Properties,” Polymer Journal, Vol.15, No.I, pp71-79 (1983), discloses a polyimine with the following formula. [ka] [Overview of the project]

[0007] This disclosure relates to a polymer comprising a repeating structure of formula (I), [ka] In the formula, Ar is an arylene or heteroarylene group in each presence, p is at least 2, and Y 1 and Y 2 One of them is CR 1 And R 1 is H or a substituent, Y 1 and Y 2 The other side provides a polymer, which is N.

[0008] Selectively, p is between 2 and 5.

[0009] Optionally, each Ar in (Ar)p is independently selected from paraphenylene, thiophene, furan, and benzobisoxazole, each of which can independently be unsubstituted or substituted with one or more substituents. Preferably, each Ar is phenylene.

[0010] Selectively, each Ar in (Ar)p is the same.

[0011] Optionally, one or more Ar groups of (Ar)p may have substituents R 2 Substituted with one or more substituents selected from R 2 In each existence, independently, F, CN, NO2, branched, linear, or cyclic C 1~40 alkyl, preferably C 1~20 alkyl, selected from, where one or more non-adjacent C atoms may be replaced by O, S, NR 5 , SiR 6 2, C=O, or COO, and R 5 is, in each occurrence, H or a substituent, and R 6 is, in each occurrence, independently, a substituent, or is unsubstituted or substituted with one or more substituents, an aryl group or heteroaryl group Ar 5 selected from. Optionally, at least one R 2 is a C 1~20 alkyl group or a C 1~19 alkoxy group.

[0012] Optionally, R 1 is H or a C 1~20 hydrocarbyl group.

[0013] In a preferred embodiment, the polymer is not fluorinated.

[0014] Optionally, the divalent linker group L is disposed within the polymer backbone, and L is selected from O, S, NR 5 , or C 1~12 alkylene group, where one or more non-adjacent C atoms may be replaced by O, S, NR 5 , SiR 6 2, CO, or COO, and R 5 is, in the occurrence, H or a substituent, and R 6 is, in the occurrence, independently, a substituent.

[0015] Optionally, the repeating structure of formula (I) is included in a repeating group of formula (II), (III), or (IV),

Chemical formula

[0016] This disclosure provides films comprising the polymers described herein.

[0017] This disclosure provides a method for forming a film as described herein, comprising depositing one or more monomers and polymerizing one or more monomers in order to form a polymer on a surface.

[0018] One or more monomers are selectively deposited from the solution.

[0019] Optionally, the surface is the surface of the functional layer of an electronic device.

[0020] This disclosure provides an apparatus comprising a heat-generating device, a heat-transferring device configured to transmit heat from the heat-generating device, and a film according to claim 10 disposed between the heat-generating device and the heat-transferring device.

[0021] This disclosure provides an electronic device comprising a film as described herein, the film being disposed on a functional layer of the electronic device.

[0022] Optionally, the film is placed in the region between the surface of the functional layer and the first surface of a first chip electrically connected to the functional layer.

[0023] Optionally, the functional layer may be a printed circuit board, an interposer, or a second chip.

[0024] Optionally, the electronic device may include a 3D chip stack.

[0025] This disclosure provides a heat sink comprising a first surface extending therefrom and an opposing second surface having a film described herein disposed thereon.

[0026] This disclosure relates to a method for forming a polymer as described herein, wherein the polymer reacts with Y 1 =Y 2 The present invention provides a method comprising polymerizing one or more monomers having a reactive group that forms a reaction group.

[0027] Optionally, this method includes polymerizing a first monomer selected from formulas (M1-A) and (M1-B) with a second monomer selected from formulas (M2-A) and (M2-B). [ka] In the formula, X 1 and X 2 One of them is the formula -C(=O)R 1 It is the basis of X 1 and X 2 The other is NH2, where q, n, and m, as well as L, are as described above.

[0028] Optionally, this method includes polymerization of the monomer of formula (M3), [ka] In the formula, X 1 and X 2 One of them is the formula -C(=O)R 1 It is the basis of X 1 and X 2 The other is NH2, where n is 0 or a positive integer, and L is as described above.

[0029] This disclosure provides formulations comprising one or more monomers for forming a polymer as described herein, and a solvent in which the one or more monomers are dissolved. [Brief explanation of the drawing]

[0030] [Figure 1] Several embodiments of electronic devices are schematically shown, and these electronic devices include a flip chip electrically connected to a substrate. [Figure 2A] Figure 1 schematically illustrates several embodiments of methods for forming the electronic device shown, in which an underfill layer is formed between the substrate and the flip chip. [Figure 2B] Figure 1 schematically illustrates several embodiments of methods for forming the electronic device shown, in which a non-conductive film is applied to the flip chip before connection to the substrate. [Figure 3] Several embodiments of 3D chip stacks are schematically shown. [Figure 4] A schematic diagram of a substrate for measuring the thermal conductivity of a film is shown. [Figure 5A] Figure 4 schematically shows the apparatus for measuring thermal conductivity, including the substrate. [Figure 5B] Figure 4 schematically shows the apparatus for measuring thermal conductivity, including the substrate.

[0031] The drawings are not drawn to scale and have various viewpoints and perspectives. The drawings are several implementations and embodiments. In addition, some components and / or operations may be separated into different blocks or combined into a single block for the purpose of considering several embodiments of the disclosed technology. Furthermore, the technology is modifiable into various modifications and alternative forms, although certain embodiments are shown in the drawings as examples and are described in detail below. However, the intent is not to limit the technology to the specific implementations described. On the contrary, the technology is intended to encompass all modifications, equivalents, and alternatives that fall within the scope of the technology as defined by the appended claims. [Modes for carrying out the invention]

[0032] Unless explicitly required otherwise in the context, words such as “including,” “including,” and “including” throughout the specification and claims should be interpreted in a comprehensive, not exclusive, sense. That is, “including, but not limited to.” Furthermore, “here,” “above,” “below,” and similar words, when used in this application, refer to the entire application, not to any specific part of it. Where the context allows, words in detailed descriptions using singular or plural may also include plural or singular, respectively. The word “or” in relation to a list of two or more items covers all interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. When used in this application, a reference to a layer “above” another layer means that the layers may be in direct contact or that one or more intervening layers may exist. A reference to a layer “on top” another layer, when used in this application, means that the layers are in direct contact.

[0033] The technical teachings provided herein may be applicable to systems other than those described below. Combinations of elements and actions from the various examples described below may provide further implementations of the technology. Some alternative implementations of the technology may include fewer, as well as additional, elements than those shown below.

[0034] These and other modifications may be made to the Art from the perspective of the following detailed description. The description describes specific examples of the Art and the best form intended, but no matter how detailed the description may seem, the Art can be carried out in many ways. As stated above, any specific terms used when describing a particular feature or aspect of the Art should not be construed as meaning that the terms have been redefined herein to limit them to specific characteristics, features, or aspects of the Art in which they relate. In general, the terms used in the following claims should not be construed as limiting the Art to the specific examples disclosed herein unless such terms are expressly defined in the section of the detailed description. Accordingly, the actual scope of the Art includes not only the disclosed examples but also all equivalent ways of carrying out or implementing the Art based on the claims.

[0035] To reduce the number of patent claims, specific aspects of the technology are presented below in the form of specific claims, although the applicant intends to present various aspects of the technology in any number of claims.

[0036] In the following description, many specific details are described for illustrative purposes to provide a full understanding of the implementations of the disclosed technology. However, it will be obvious to those skilled in the art that the embodiments of the disclosed technology can be implemented without some of these specific details.

[0037] The inventors have found that a film containing or made of a polymer having a repeating structure of formula (I) can provide high thermal conductivity. [ka] In the formula, Ar is an arylene or heteroarylene group in each presence, p is at least 2, and Y 1 and Y 2 One of them is CR 1 And R 1 is H or a substituent, Y 1 and Y2 The other side is N.

[0038] The extensional stiffness rod-type structure of equation (I) can enhance the thermal conductivity of the polymer compared to the case where p=1.

[0039] Optionally, the thermal conductivity of the polymers described herein is at least 0.15 Wm². -1 K -1 , optionally at least 0.2 or 0.3 Wm -1 K -1 That is the case. p is preferably between 2 and 5.

[0040] In each (Ar)p entity, Ar may be the same or different, preferably the same.

[0041] Examples of Ar groups include, but are not limited to, paraphenylene, thiophene, furan, and benzobisoxazole, each of which can independently be unsubstituted or substituted with one or more substituents. Paraphenylene is preferred.

[0042] Examples of the (Ar)p group include, but are not limited to, the groups of formula (Va) and (Vb): [ka] In the formula, R 2 w is independently a substituent in existence, and w is independently 0 or a positive integer in existence.

[0043] A preferred group (Ar)p has the formula (Vc-1): [ka]

[0044] R 1 Preferably H or C 1~20 A hydrocarbyl group, more preferably H.

[0045] C as described anywhere in this specification 1~20 The hydrocarbyl group is preferably C 1~20 Alkyl, unsubstituted phenyl, and one or more C 1~12 Selected from alkyl-substituted phenyl compounds.

[0046] (Ar) p One or more Ar groups have one or more substituents R 2 It is replaced by R. Preferably, 2 In each existence, independently, F, CN Sofa NO2, Branched, linear, or annular C 1~40 Alkyl, preferably C 1~20 Selected from alkyl groups, with one or more non-adjacent C atoms, O, S, NR 5 , SiR 6 2. C can be replaced with O, or COO, R 5 In each presence, is H or a substituent, preferably H or C 1~20 It is a hydrocarbyl group, R 6 In each existence, independently, is a substituent, and optionally, C 1~20 It is a hydrocarbyl group, or An aryl group or / or heteroaryl group Ar that is unsubstituted, or has one or more substituents, or is optionally substituted with phenyl. 5 And phenyl is either unsubstituted or F, CN, NO2, and branched, linear or cyclic C 1~20 Alkyl (one or more non-adjacent C atoms are O, S, NR) 5 , SiR 6 2. Can be replaced with one or more substituents selected from C=O or COO.

[0047] Preferably, at least one substituent R 2 , optionally, each substituent R 2 C 1~20 Alkyl, C 1~20 Alkoxy, or formula -(Ak1 ) y -(OCH2CH2) z -Ak 2 is a group, and Ak 1 is a C 1~4 alkylene group, y is 0 or 1, z is 1 to 15, and Ak 2 is a C 1~4 alkyl group. More preferably, R 2 is a C 1~12 alkyl or C 1~12 alkoxy. C 1~12 alkoxy is particularly preferred.

[0048] The polymer may contain a divalent linker group L disposed within the polymer backbone, and L is selected from O, S, NR 5 , or C 1~12 an alkylene group, and one or more non-adjacent C atoms of the C 2~12 alkylene group may be replaced by O, S, NR 5 , SiR 6 2, CO, or COO.

[0049] In some embodiments, the divalent linker group L is disposed between two Ar groups and is directly linked to the two Ar groups.

[0050] In some embodiments, the divalent linker group L is disposed between an Ar group and an imine (-C(R 1 )=N-) group and is directly linked.

[0051] In some embodiments, the divalent linker group L is disposed between two imine (-C(R 1 )=N-) groups and is directly linked.

[0052] The polymer can be formed by polymerizing one or more monomers having reactive groups that react to form imines. The repeating structure of formula (I) can be part of a larger repeating unit of the polymer formed by polymerizing one or more monomers. Exemplary repeating units include, but are not limited to, formulas (II)-(IV): [ka] (In the formula, Ar, p, Y 1 , Y 2 , and L are as explained above, q is at least 1, preferably 1 to 5, more preferably 1 to 3. n is 0 or a positive integer, preferably 0 or 1 to 5, more preferably 0, 1, 2, or 3, and m is 0 or a positive integer, preferably 0 or 1 to 5, more preferably 0, 1, 2, or 3).

[0053] If q is greater than 1, each Ar in (Ar)q may be the same or different, preferably the same.

[0054] If n is greater than 1, each Ar in (Ar)n may be the same or different, preferably the same.

[0055] When m is greater than 1, each Ar in (Ar)m may be the same or different, preferably the same.

[0056] The preferred Ar groups of (Ar)q, (Ar)m, and (Ar)m are as described with respect to (Ar)p.

[0057] The repeating units of the polymer may be the same or different. In some embodiments, the polymer contains a mixture of different repeating units of formulas (II) to (IV). The polymer may contain one or more of the following: different repeating units of formula (II), different repeating units of formula (III), different repeating units of formula (IV), and repeating units selected from one of formulas (II) to (IV) and at least one other repeating unit selected from another one of formulas (II) to (IV). In preferred embodiments, the polymer contains repeating units that do not contain a divalent linker group L, and repeating units that have a divalent linker group L, for example, the repeating unit of formula (II) and the repeating unit of formula (III).

[0058] When n and m are each 0, the repeating unit of formula (III) has formula (IIIa).

Chemical formula

[0059] The polymer may be substituted with groups for bonding polymer chains together, for example, hydrogen bonds or covalent bonds, and may enhance the long-range order of the polymer.

[0060] The polymers described herein are preferably at least partially crystalline.

[0061] The polymers described herein may undergo pi-pi stacking when deposited as a film.

[0062] The polystyrene equivalent number average molecular weight (Mn) of the polymers described herein, measured by gel permeation chromatography, is about 1×10 3 ~1×10 8 , preferably 1×10 4 ~5×10 6 and can be in the range of. The polystyrene equivalent weight average molecular weight (Mw) of the polymers described herein is 1×10 3 ~1×10 8 , preferably 1×10 4 ~1×10 7 and can be.

[0063] Polymerization The polymer can be formed by polymerizing one or more monomers having reactive groups that react to form imines.

[0064] In some embodiments, the polymers described herein are formed by polymerizing a first monomer containing a group of formula (I) and two reactive groups X 1 with a second monomer containing two reactive groups X 2 , where one of X1 and X2 is of the formula -C(=O)R1 It is the basis of X 1 and X 2 The other is NH2.

[0065] Optionally, according to these embodiments, the first monomer is selected from formulas (M1-A)-(M1-B), and the second monomer is selected from formulas (M2-A) and (M2-B). [ka]

[0066] In some embodiments, X 1 Only one monomer substituted with a group, and X 2 Only one monomer substituted with the group reacts. It will be understood that the polymer formed from these monomers contains only one repeating unit structure.

[0067] In some embodiments, X 1 Two or more different monomers substituted with a group, and / or X 2 Two or more different monomers substituted with a group are reacted. It will be understood that the polymer formed from these monomers will contain two or more different repeating unit structures.

[0068] In some embodiments, polymers containing the repeating structure of formula (I) can be formed by polymerization of monomers of formula (M3): [ka]

[0069] In some embodiments, only one monomer of formula (M3) is reacted. It will be understood that the polymer formed from this monomer contains only one repeating unit structure.

[0070] In some embodiments, two or more different monomers of formula (M3) are reacted. It will be understood that the polymer formed from these monomers contains two or more different repeating unit structures.

[0071] X 1 and X 2 The reaction between these two substances can be catalyzed by a Lewis acid. The Lewis acid may or may not be Bronstead-Lowry acid.

[0072] The inventors have surprisingly found that polymerizing monomers in the presence of a Lewis acid catalyst can increase the thermal conductivity of polymers, as described herein, compared to the formation of polymers without a catalyst.

[0073] Examples of catalysts include, but are not limited to, sulfonic acids and their salts, such as p-toluenesulfonic acid; trifluic acid; and their salts. An example trifluic acid salt is scandium triflate, Sc(Trf)3. The catalyst may be supplied in an amount of 0.01 to 0.3 molar equivalents of the total number of moles of one or more monomers.

[0074] Film formation The formation of a polymer-containing film as described herein may include the formation of a precursor film containing one or more monomers for forming the polymer, followed by polymerization of the monomers, hereinafter referred to as in-situ polymerization. The precursor film may consist of one or more monomers for forming the polymer, or the precursor film may be a composition containing one or more further materials, such as a Lewis acid catalyst, as described herein.

[0075] In some preferred embodiments of in-situ polymerization, precursor film formation involves the deposition of a monomer formulation containing one or more monomers dissolved in one or more solvents. According to these embodiments, in-situ polymerization is preferably carried out in solution. The monomer formulation may or may not contain a catalyst.

[0076] The solvent may be selected according to its ability to dissolve the monomer or each monomer. Exemplary solvents include those with one or more substituents (optionally, one or more substituents are C 1~12 Alkyl, C 1~12 Examples of solvents include, but are not limited to, benzene or naphthalene substituted with alkoxy, (selected from F and Cl), ethers, esters, halogenated alkanes, ketones, sulfoxides, and mixtures thereof. Examples of solvents include, but are not limited to, xylene, 1,2,4-trimethylbenzene, mesitylene, 1-methylnaphthalene, 1-chloronaphthalene, diiodomethane, anisole, N-methylpyrrolidone, 1,2-dimethoxybenzene, dimethyl sulfoxide 1,3-dimethyl-2-imidazolidinone, and cyclopentanone.

[0077] The concentration of each monomer dissolved in the monomer formulation is preferably in the range of about 1 to 50 mg / ml, more preferably about 10 to 40 mg / ml. One or more monomers can be dissolved by heating the monomer formulation.

[0078] The polymer precursor film may be heated before and / or after polymerization. In some embodiments, the polymer precursor film may be dried at a temperature of 50–70°C, optionally up to about 100°C. The dried film may be heated at a temperature above 100°C, optionally in the range of 100–200°C. The temperature applied before, during, or after drying may be below the melting point of the monomer, or, if two or more monomers are present, below the melting point of the monomer with the lowest melting point. The temperature applied before, during, or after drying may be above the melting point of the monomer, and, if two or more monomers are present, above the melting point of the monomer with the lowest melting point.

[0079] In some preferred embodiments of in-situ polymerization, a monomer formulation containing monomer particles mixed with a liquid is deposited on a surface to form a polymer precursor film, and the precursor film is heated to at least the melting point of the monomers, or, if two or more monomers are present, to at least the melting point of the monomer having the lowest melting point. Optionally, the polymer precursor film is heated below the melting point of the lowest monomer, and the liquid is expelled before the heating temperature rises to at least this melting point. The amount and / or nature of the liquid will be understood to be such that the monomer particles do not dissolve in the liquid. Preferably, or each monomer is slightly soluble or insoluble in the liquid. The liquid may be a single liquid material, or two or more liquid materials, e.g., water and C 1~6 It may be a mixture of one or more liquids selected from alcohols. The monomer formulations according to these embodiments may be, for example, suspensions or pastes, and a suitable deposition method may be selected accordingly.

[0080] Monomer formulations described anywhere in this specification may be deposited by any suitable solution deposition technique, including but not limited to spin coating, dip coating, drop casting, spray coating, and blade coating.

[0081] The film may consist of a polymer or may contain one or more further materials, optionally one or more amorphous polymers, such as polystyrene, polyethylene, or polypropylene, and / or one or more thermally conductive materials, such as boron nitride.

[0082] In some embodiments, the film contains thermally conductive particles dispersed therein.

[0083] In some embodiments, the film does not contain thermally conductive particles such as boron nitride.

[0084] Optionally, films comprising or consisting of the polymers described herein have a thickness in the range of 1 to 100 microns, preferably 10 to 100 microns.

[0085] Purpose Films containing polymers as described herein may be used in any known application of thermally conductive films. The films described herein may be placed between the surface of a heat-generating device and a heat-transferring device configured to transfer heat from the heat-generating device, for example, in any known thermal conduction control application.

[0086] In this arrangement, it will be understood that the film is configured to transfer heat from a heat generating device to a heat transfer device. The film preferably has a first surface that is in direct contact with the surface of the heat generating device, and / or a second surface that is opposite the first surface and is in direct contact with the surface of the heat transfer device.

[0087] A heat-generating device can be an electronic device.

[0088] Any passive or active heat transfer device known to those skilled in the art may be used, including, but not limited to, a heat sink having a surface in contact with a film and an opposite surface having one or more heat dissipation mechanisms, such as fins, pipes, or channels, configured to transfer heat to a fluid flowing through the pipes or channels. The fluid may or may not undergo a phase change upon heat absorption.

[0089] Preferably, the film is a thermal conductive layer for an electronic device.

[0090] Heat can be transferred from a surface by placing a layer containing a thermally conductive film, as described herein, adjacent to the surface. The thermally conductive film may be in direct contact with the surface or separated from the surface by one or more thermally conductive layers.

[0091] The film described herein may be placed on the surface of a heatsink and facing the surface of the heatsink having fins extending from the heatsink. During use, the film may be placed between the heatsink and electrical components.

[0092] The films described herein may be heat spreader layers placed on the surface of a printed circuit board, such as a PCB for use in an LED array.

[0093] The films described herein are electrically nonconductive films, for example, which can be used as underfill for flip chips, and flip chips include, but are not limited to, multi-chips stacked in three dimensions.

[0094] Figure 1 shows an electronic device comprising a chip 105, a substrate 101 (e.g., a printed circuit board), and a conductive interconnect 107 between a conductive pad 103 on the surface of the substrate 101 and the chip 105. An underfill 109 comprising or consisting of a polymer as described herein fills the area between the chip 105 and the substrate 101. Optionally, the polymer is crosslinked.

[0095] Referring to Figure 2A, in some embodiments, the formation of an electronic device involves bringing conductive bumps 107', e.g., solder bumps, into contact with conductive pads 103 disposed on a substrate 101, e.g., a printed circuit board, to form interconnects 107 from the conductive bumps 107'. The formation of an underfill 109 containing a polymer, as described herein, involves applying a formulation containing one or more monomers to the overlapping region between the chip 105 and the substrate 101. Optionally, the polymer is crosslinked by, for example, heat and / or UV treatment following the application of the formulation and the reaction of one or more monomers.

[0096] Referring to Figure 2B, in some embodiments, a polymer precursor film is formed on the surface of a chip 105 supporting the conductive bumps 107'. Figure 4B shows complete coverage of the conductive bumps 107', but it will be understood that the conductive bumps 107' can be partially covered such that a portion of the conductive bumps 107' protrudes from the surface of the film 109. The conductive bumps 107' then come into contact with a substrate 101, for example, a conductive pad 103 placed on a printed circuit board, to form a conductive interconnect between the substrate and the chip. Formation of the conductive interconnect may involve the application of heat and / or pressure.

[0097] If the polymer of film 109 is crosslinked, crosslinking may occur before, during, or after the conductive bump 107' comes into contact with the conductive pad 103.

[0098] Two or more chips may be arranged between them and connected by a film containing a polymer as described herein. Figure 3 shows a 3D stack of chips 105 according to several embodiments, where each chip 105 is sandwiched between an interposer 111 and non-conductive films 109 placed between adjacent interposers and the chip surface, and between a substrate 101 (e.g., a printed circuit board) and the first chip of the 3D stack. At least one non-conductive film 109 contains a polymer as described herein. Through-vias 115 are formed through the chips 105 and the interposers. The 3D stack may include a heat sink 113 placed on its surface.

[0099] In some embodiments, a film containing or comprising the polymer described herein may be placed between an electronic device and a heat sink. [Examples]

[0100] In-situ solution polymerization The polymers were formed by depositing solutions of the diamine monomers and dialdehyde monomers listed in Table 1 and reacting the monomers. Some monomers were reacted in the presence of a Lewis acid catalyst. Some polymers were annealed after polymerization.

[0101] Monomers were dissolved in a solvent at the same desired concentration (w / v), for example, 10 mg / ml, and optionally heated to 80°C to aid dissolution. The monomer inks were mixed by volume to produce an equimolar mixture of monomers. Catalysts may be added by the same method of pre-dissolution and volumetric mixing to achieve the desired molar ratio of catalyst to monomer. For illustrative purposes, a 1:1:0.15 molar mixture of monomers A2 (Mw 108.144) and B2 (Mw 454.65) with 10 mg / ml of scandium triflate catalyst (Mw 492.16) was prepared by first preparing bulk solutions of each component at 10 mg / ml, and then mixing them in a volume ratio of 0.18:0.758:0.062.

[0102] After mixing, the ink is quickly drop-cast onto the substrate shown below for thermal conductivity measurement. A gasket, prepared from a 0.5 mm thick fluorosilicone rubber sheet (Silex Silicones Ltd) and applied to the substrate, is used to contain the ink within a designated area (18 × 10 mm rectangle) of the drop-cast procedure. The wet film is dried by evaporation on a hot plate, which can be room temperature or any temperature below the solvent boiling point. In the examples in the table, the drying temperature was consistently 50°C. After drying, the gasket is removed, and the film is optionally annealed at 170°C for 2 hours.

[0103] The results are shown in Table 1. [Table 1] [ka]

[0104] Comparative polymer 1 was formed from a 1:1 v / v mixture of Epikote resin 862 and Epikure curing agent 866 (both from Hexion), to which 0.1% tetrabutylphosphonium bromide (purchased from Sigma) was added.

[0105] The thermal conductivity was measured as follows. Monomers without alkyl substituents or alkylene linkers to enhance solubility were found to form poorer films, but the thermal conductivity of these films can be enhanced by annealing and / or the use of catalysts.

[0106] Thermal conductivity measurement A sensor substrate 600 (approximately 25 mm × 25 mm) shown in Figure 4 was used for measuring thermal conductivity as described herein. The substrate has a 200 nm thick polyethylene naphthalate (PEN) film (DuPont Teonex Q83, 25 μm), and the heating structure consists of a 20 micron wide heater line 610 and a 500 micron wide busbar 620 for the application of current and contact pads 640. The sensing structure reflects the heating structure except that the heater line is replaced with a 200 micron wide sensor line 630.

[0107] Referring to Figures 5A and 5B, the sensor substrate 600, having the film to be measured, is tuned via a PID system so that its temperature can be controlled by software, and is placed on a temperature-controlled aluminum block. The aluminum block has a long notch 720 cut into it, 1 mm wide and approximately 1 mm deep. The sensor substrate 600 is placed on the notch such that the central heater line 610 is aligned with the center of the notch 720 and the sensor line 630 is aligned with the end of the notch. A PMMA sheet 730 (2 mm thick) with a notch cut-through matching the notch cut-through of the aluminum block 710 is placed on top, and an additional piece of flat PMMA sheet 740 (4 mm thick) is placed on top to surround the device. The entire assembly is clamped at position 750 using bolts and nuts. The heater line is connected to a source meter unit (Keithley 2400) using a 4-wire measuring device. The sensor line is connected to a multimeter unit (Keithley 2000) using a 4-wire device.

[0108] The assembly temperature is first stabilized at a predetermined temperature. Then, the resistance of the heater line and temperature sensor is measured. To measure the resistance of the heater line without causing excessive heating, a low current is supplied, the voltage is measured in short pulses, and time between pulses is allowed for heat dissipation. A constant DC current passes through the heater line, causing resistive heating. Due to the arrangement of the substrate in the assembly, heat flows through the substrate and film to the aluminum block acting as a heat sink, setting an approximate one-dimensional steady-state heat flux. In this state, the power dissipated by the heater line, as well as the resistance of the heater line and temperature sensor, are measured. This process is repeated each time the supplied current is increased, and the complete process is repeated at the next temperature setpoint.

[0109] The resistance of the heater line and sensor line under conditions of no heat flow at different temperature setpoints is used as calibration data in the linear fit of resistance and temperature, allowing the temperature of the resistive element to be determined under conditions of steady heat flow. Therefore, the temperature gradient between the heater line and temperature sensor (aligned with the heat sink) can be calculated. It is assumed that the power dissipated in the heater line is completely converted into thermal energy Q. A linear fit is then created between dT and Q, with additional parameters for the length of the heater line where power is measured (L, 14.4 mm), the distance between voltage sensing points, and the gap width (2w, 1 mm). This provides a measurement of the conductivity C of the device under test, which is affected by losses related to conductive heat transfer within the substrate and convective and radiant heat transfer (h) to the environment.

[0110] To calculate the thermal conductivity, the same measurement process is performed on the substrate without the test film (substrate only). It is assumed that the losses when measuring coated and uncoated substrates are approximately the same. Device measurement value (C F+S ) from the substrate (C S The conductivity of the film is subtracted to adjust for these losses. Then, the conductivity of only the resulting film is calculated based on the film thickness (d F By dividing by ), the thermal conductivity (k F Calculate the total thickness. Determine the film thickness using a digital micrometer by measuring the total thickness and subtracting the substrate thickness.

number

[0111] Differential scanning calorimetry of monomers Differential scanning calorimetry was performed on the diarydehyde monomers B2, B3, and B4 using a Perkin Elmer DSC8500 instrument. The samples were heated and cooled in two cycles from -52°C to 258°C at a rate of 10°C / min. Significant transition temperatures from the second cycle are shown in Table 2.

[0112] The results shown in Table 2 indicate that alkoxy-substituted monomers B2 and B3 have higher crystallinity compared to alkyl-substituted monomer B2. [Table 2]

[0113] Effects of polymerization The effect of the film formation method on thermal conductivity was investigated.

[0114] The polymer was prepared from monomer A3 and either monomer B2 or B3 by in-situ solution polymerization or in-situ melt polymerization as described above.

[0115] In-situ solution polymerization was carried out as described above.

[0116] For in-situ melt polymerization, equimolar monomers A3 and B3 were weighed and transferred to a mortar, a small amount of non-solvent liquid was added to act as a grinding agent, and the mixture was ground into a paste using a pestle. Additional liquid was added to form a dispersion at a concentration of 20 mg / ml. After mixing, the ink was rapidly drop-cast onto the substrate, as previously described, for thermal conductivity measurement.

[0117] A gasket prepared from a 0.5 mm thick fluorosilicone rubber sheet (Silex Silicones Ltd) and applied to the substrate is used to contain the ink within a predetermined area (18 × 10 mm rectangle) for the drop-casting procedure. The wet film is dried by evaporation on a hot plate set to a low temperature, e.g., 40°C, to avoid causing dissolution or reaction of the dispersed solid. The substrate is then removed from the hot plate and transferred to a second hot plate preheated to 140°C. It is observed that the monomer first melts into a liquid state, then a polymer film is formed, returning the sample to a solid state. After this has happened (within 5 minutes), the substrate is moved to a cooling station and the silicone gasket is removed.

[0118] The thermal conductivity was measured using the method described above. [Table 3]

Claims

1. A polymer comprising a repeating structure of formula (I), 【Chemistry 1】 In the formula, Ar is an arylene group in each instance, p is at least 3, and Y １ and Y ２ One of them is CR １ And R １ is H or a substituent, Y １ and Y ２ The other is N, The polymer in question is a linear polymer.

2. The polymer according to claim 1, wherein p is 3 to 5.

3. The polymer according to claim 1 or 2, wherein each Ar in (Ar)p is paraphenylene, and each paraphenylene can independently be unsubstituted or substituted with one or more substituents.

4. The polymer according to any one of claims 1 to 3, wherein each Ar in (Ar)p is the same.

5. (Ar) ｐ One or more Ar groups of ２ are substituted with one or more substituents selected from substituent R ２ which, in each occurrence, is independently F, CN, NO ２ 、 Branched, linear, or annular C １～２０ Selected from alkyl groups, with one or more non-adjacent carbon atoms, O, S, NR ５ , SiR ６ ２ C can be replaced with O or COO, R ５ In each instance, is H or a substituent, and R ６ In each existence, independently, is a substituent, or An aryl group or heteroaryl group Ar that is unsubstituted or substituted with one or more substituents. ５ The polymer according to any one of claims 1 to 4.

6. at least one R ２ C １～２０ Alkyl alkyl group or C １～１９ The polymer according to claim 5, wherein the group is an alkoxy group.

7. R １ is H or C １～２０ A polymer according to any one of claims 1 to 6, wherein the group is a hydrocarbyl group.

8. The divalent linker group L is located within the polymer backbone, and L is O, S, NR ５ , or C １～１２ Selected alkylene group, C ２～１２ One or more non-adjacent carbon atoms in the alkylene group are O, S, NR ５ , SiR ６ ２ , CO or COO can be used as replacements, R ５ In each instance, is H or a substituent, and R ６ The polymer according to any one of claims 1 to 3, wherein each substituent is independently present in each instance.

9. The repeating structure of formula (I) is included in the repeating group of formula (II), (III), or (IV), 【Chemistry 2】 During the ceremony, q is at least 1, n is 0 or a positive integer, m is 0 or a positive integer, and The polymer according to any one of claims 1 to 8, wherein L is as defined in claim 8.

10. A film comprising the polymer according to any one of claims 1 to 9.

11. A method for forming a film according to claim 10, comprising depositing one or more monomers and polymerizing the one or more monomers in order to form the polymer on a surface.

12. The method according to claim 11, wherein the one or more monomers are deposited from a solution.

13. The method according to claim 11 or 12, wherein the surface is the surface of a functional layer of an electronic device.

14. An apparatus comprising: a heating device; a heat transfer device configured to transfer heat from the heating device; and a film according to claim 10 disposed between the heating device and the heat transfer device.

15. An electronic device comprising the film described in claim 10, wherein the film is disposed on the functional layer of the electronic device.

16. The electronic device according to claim 15, wherein the film is disposed in a region between the surface of the functional layer and the first surface of a first chip electrically connected to the functional layer.

17. The electronic device according to claim 16, wherein the functional layer is a printed circuit board, an interposer, or a second chip.

18. The electronic device according to claim 15, 16, or 17, wherein the electronic device comprises a 3D chip stack.

19. A heat sink comprising a first surface extending therefrom, and an opposing second surface having the film described in claim 10 disposed thereon.

20. A method for forming the polymer according to any one of claims 1 to 9, wherein the polymer reacts with Y １ = Y ２ A method comprising polymerizing one or more monomers having a reactive group that forms a compound.

21. The process involves polymerizing a first monomer selected from formulas (M1-A) and (M1-B) with a second monomer selected from formulas (M2-A) and (M2-B), 【Transformation 3】 In the formula, X １ and X ２ One of them is formula -C(=O)R １ It is the basis of X １ and X ２ The other side is NH ２ And q, n, and m are as defined in claim 9, and L is as defined in claim 8, The method according to claim 20, wherein each monomer has only two groups selected from X1 and X2.

22. The polymerization of monomers of formula (M3) is included. 【Chemistry 4】 In the formula, X １ and X ２ One of them is formula -C(=O)R １ It is the basis of X １ and X ２ The other side is NH ２ n is 0 or a positive integer, and L is as defined in claim 8. The method according to claim 20, wherein the monomer has only two groups selected from X1 and X2.

23. A formulation comprising one or more monomers for forming a polymer according to any one of claims 1 to 9, and a liquid, The monomer is (i) At least one first monomer selected from formulas (M1-A) and (M1-B), and at least one second monomer selected from formulas (M2-A) and (M2-B): or (ii) At least one monomer of formula (M3): In the formula, one of X1 and X2 is the base of formula -C(=O)R1, the other of X1 and X2 is NH2, q, n, and m are as defined in claim 9, and L is as defined in claim 8. Each monomer has only two groups selected from X1 and X2. The said formulation.

24. The formulation according to claim 23, wherein the liquid is a solvent, and the one or more monomers are dissolved in the solvent.

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