Thermally conductive polymers

Abstract

A polymer comprising a repeating unit of formula (I), wherein X 1 and X 2 are each independently selected from formula (II) and formula (III), provided that at least one of X 1 and X 2 is a group of formula (III). In (II) - (III), Ar 1 , Ar 2 and Ar 3 are each independently an arylene group or a heteroarylene group at each occurrence, m is at least 1, p is at least 1, q is at least 1, and L is optionally a substituted chain of methylene groups and O atoms. One of Y 1 and Y 2 is CR 1 , where R 1 is H or a substituent, and the other of Y 1 and Y 2 is N. One of Y 3 and Y 4 is CR 1 , and the other of Y 3 and Y 4 is N [Chemical Formula 1] TIFF2026511326000024.tif31137 [Chemical Formula 2] TIFF2026511326000025.tif10145

Description

[Background technology]

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

[0002] Suematsu et al, "Polyimine, a C=N Double Bond Containing Polymers: Synthesis and Properties" Polymer Journal, Vol. 15, No. I, pp 71-79 (1983) describes the formula [ka] The polyimines are disclosed.

[0003] International Publication No. 2022 / 136584 discloses a thermally conductive polymer formed by the reaction of a dialdehyde and a diamine. [Overview of the project]

[0004] This disclosure relates to a polymer comprising repeating units of formula (I), [ka] During the ceremony, X 1 and X 2 These are selected independently from equations (II) and (III), but X 1 and X 2 At least one of them is a base of equation (III), [ka] In the formula, Ar 1 Ar 2 and Ar 3is, in each occurrence, independently an arylene group or a heteroarylene group, m is at least 1, p is at least 1, q is at least 1, and L is optionally a chain substituted with a methylene group and an O atom, Y 1 and Y 2 one of which is CR 1 wherein R 1 is H or a substituent, and Y 1 and Y 2 the other one of which is N, and Y 3 and Y 4 one of which is CR 1 and Y 3 and Y 4 the other one of which is N.

[0005] Optionally, each R 1 is H or a hydrocarbyl group of C 1~20 .

[0006] Optionally, L contains at least three atoms separating Ar 2 from Ar 3 .

[0007] Optionally, the atoms of L bonded to Ar 2 and Ar 3 are each O.

[0008] Optionally, one of X 1 and X 2 is a group of formula (II), and the other one of X 1 and X 2 is a group of formula (III).

[0009] Optionally, m is at least 2.

[0010] Optionally, both of Y 1 and Y 4 are the same one of CR 1 and N, and Y 2 and Y 3Both have the same reaction, CR 1 It is the other one of N.

[0011] Optional, Ar 1 Ar 2 and Ar 3 Each occurrence is independently selected from a 6- to 12-membered arylene group or a condensed 5- or 6-membered heteroarylene group.

[0012] Optional, Ar 1 Ar 2 and Ar 3 In each occurrence, it is independently an unsubstituted or substituted para-phenylene group.

[0013] Optionally, p and q are each 1.

[0014] This disclosure provides a method for forming a polymer comprising repeating units of formula (I), the method comprising reacting a first monomer of formula M1 with a second monomer of formula M2, [ka] In the formula, each RG 1 C(=O)R 1 A first reactive group selected from and NH2, where each RG2 is C(=O)R 1 And it is another second reactive molecule of NH2.

[0015] This disclosure provides a film comprising a polymer containing repeating units of formula (I).

[0016] In some embodiments, the film is formed by a heat treatment method. Optionally, the heat treatment method may be selected from extrusion molding, injection molding, thermocompression bonding, and hot press molding or melt press molding.

[0017] Optionally, the formation of the film includes depositing a polymer on a surface, heating the deposited polymer to a temperature above its phase transition temperature, and cooling the polymer to a temperature below the phase transition temperature at a rate of 2°C per minute or less, optionally at a rate of 1°C per minute or less. Optionally, the polymer is cooled to a temperature at least 25°C or at least 50°C below its phase transition temperature at a rate of 2°C per minute or less, optionally at a rate of 1°C per minute or less.

[0018] This disclosure provides an electronic device, which includes a film described herein disposed on the surface of a functional layer of the electronic device.

[0019] 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.

[0020] Optionally, the functional layer may be a printed circuit board, an interposer, or a second chip.

[0021] Optionally, the electronic device may include a 3D chip stack.

[0022] This disclosure provides an apparatus comprising a heating device, a heat transfer device configured to transfer heat from the heating device, and a film according to this disclosure disposed between the heating device and the heat transfer device.

[0023] This disclosure provides a heat sink comprising a first surface and a second surface on the opposite side, wherein the first surface has fins extending therefrom, and the second surface has a film according to this specification disposed thereon.

[0024] This disclosure provides a formulation comprising a first monomer of formula M1 and a second monomer of formula M2 dissolved or dispersed in a solvent or solvent mixture. [ka] In the formula, X 1 and X 2In that case, as mentioned above, each RG 1 C(=O)R 1 and a first reactive group selected from NH2, each RG 2 C(=O)R 1 And it is another second reactive molecule of NH2.

[0025] This disclosure provides a method for forming a polymer, the method comprising reacting a polymerization mixture comprising a first monomer of formula M1 and a second monomer of formula M2, [ka] In the formula, each RG 1 C(=O)R 1 and a first reactive group selected from NH2, each RG 2 C(=O)R 1 And another second reactive group of NH2, R 1 is H or a substituent, and X 3 and X 4 These are independently selected from the bases of equations (II) and (III), [ka] In the formula, Ar 1 Ar 2 and Ar 3 In each occurrence, independently, is an arylene group or a heteroarylene group, m is at least 1, p is at least 1, and q is at least 1. Furthermore, L' is replaced by C of any choice. 1~10 It is an alkylene group, and one or more non-adjacent C- atoms are O, S, NR 5 , SiR 6 2. C may be substituted with O or COO, and in the formula R 5 In each occurrence, is H or a substituent, and R 6 Each instance is independently a substituent, Furthermore, the polymerization mixture comprises a solvent or solvent mixture in which the first monomer, the second monomer, and the aromatic alcohol are dissolved.

[0026] Optionally, the aromatic alcohol is a benzene substituted with at least one hydroxyl group.

[0027] Optionally, the solvent or solvent mixture may include alkylated benzene.

[0028] Optionally, the solvent or solvent mixture may include tetrahydrofuran. [Brief explanation of the drawing]

[0029] [Figure 1] This schematic diagram illustrates an electronic device, including a flip chip electrically connected to a substrate, according to several embodiments. [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 it is connected 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] A schematic diagram of the apparatus for measuring the thermal conductivity, including the substrate shown in Figure 4, is provided. [Figure 5B] A schematic diagram of the apparatus for measuring the thermal conductivity, including the substrate shown in Figure 4, is provided. [Figure 6A] These are photographs of heat-treated polymer films according to several embodiments. [Figure 6B] These are photographs of heat-treated polymer films according to several embodiments. [Figure 7A] These are photographs of untreated polymer films according to several embodiments. [Figure 7B]These are photographs of untreated polymer films according to several embodiments.

[0030] The drawings are not drawn to scale and have various viewpoints and angles. The drawings show several implementations and embodiments. Furthermore, some components and / or operations may be separated into different blocks or combined into a single block for the purpose of illustrating some embodiments of the disclosed technology. Furthermore, the technology follows various modifications and alternative forms, but certain embodiments are shown in the drawings as examples and described in detail below. However, the technology is not intended to be limited to the specific implementations described. In contrast, 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]

[0031] Unless the context clearly requires otherwise, throughout the specification and claims, terms such as “comprise” and “comprising” shall be interpreted in a comprehensive sense, i.e., “including, but not limited to,” as opposed to an exclusive or thorough sense. Furthermore, terms such as “here,” “above,” “below,” and terms of similar intent, when used in this application, refer to the entire application and not to any particular part thereof. Where the context allows, terms in forms for carrying out an invention using singular or plural may also include plural or singular, respectively. The word “or” in relation to a list of two or more items encompasses all of the following 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. “Above” another layer means that a layer may be in direct contact with another layer, or that one or more intervening layers may exist. When used in this application, a reference to a layer “above” another layer means that the layers are in direct contact. Citations of chemical elements include their isotopes.

[0032] The teachings of the technology provided herein may be applied to systems other than those described below. Further embodiments of the technology can be provided by combining elements and actions of the various embodiments described below. Some alternative implementations of the technology may include fewer elements than those described below, as well as additional elements.

[0033] Taking into consideration the detailed description below, these and other modifications may be made to the Art. This specification describes certain examples of the Art and the best practices intended, but no matter how detailed the description may seem, the Art can be carried out in many ways. As described above, any specific term used to describe a particular feature or aspect of the Art should not be construed as meaning that the term is redefined herein to be limited to any particular feature, aspect, or aspect of the Art relating to that term. In general, the terms used in the following claims should not be construed as limiting the Art to the specific embodiments disclosed herein unless such terms are explicitly defined elsewhere in the section on modes for carrying out the invention. Thus, the actual scope of the Art includes not only the disclosed embodiments but also all equivalent ways of practicing or implementing the Art under the claims.

[0034] To reduce the number of patent claims, certain aspects of the technology are presented below in the form of specific claims, although the applicant will consider various aspects of the technology in any number of claims.

[0035] In the following description, many specific details are described for illustrative purposes and to provide a full understanding of the implementations of the disclosed technology. However, it will be apparent to those skilled in the art that the embodiments of the disclosed technology can be implemented without some of these specific details.

[0036] The inventors of this invention have found formula (I) [ka] We have found that a film containing or comprising a polymer containing repeating units can provide high thermal conductivity. During the ceremony, X 1 and X 2 These are selected independently from equations (II) and (III), but X 1 and X 2 At least one of them is a base of equation (III), [ka] In the formula, Ar 1 Ar 2 and Ar 3 In each occurrence, is independently an arylene group or a heteroarylene group, m is at least 1, p is at least 1, q is at least 1, and L is optionally a chain substituted with a methylene (-CH2-) group and an O atom. Y 1 and Y 2 One of them is CR 1 And in the formula R 1 is H or a substituent, and Y 1 and Y 2 The other one of them is N, and Y 3 and Y 4 One of them is CR 1 And Y 3 and Y 4 The other one is N.

[0037] R 1 Preferably H or C 1~20 A hydrocarbyl group, more preferably H or C 1~6 The alkyl group is most preferably H.

[0038] The carbon atoms or oxygen atoms in L may be arranged in any order. Ideally, no two oxygen atoms in the chain should be directly adjacent. Preferably, the terminal atoms of L, i.e., Ar 2 and Ar 3 The L atoms bonded to each other are each oxygen atoms.

[0039] One or more H atoms of the methylene group of L may be substituted with one or more substituents. Optionally, one or more H atoms may be substituted with F, C 1~6 alkyl or C 1~6 may be substituted with fluoroalkyl.

[0040] Preferably, L contains at least three or at least four atoms separating Ar 2 and Ar 3 from each other.

[0041] Examples of exemplary groups of L include, but are not limited to, -OCH2CH2O- and -OCH2O-.

[0042] Optionally, each of X 1 and X 2 is a group of formula (III).

[0043] Preferably, one of X 1 and X 2 is a group of formula (II), and the other of X 1 and X 2 is a group of formula (III).

[0044] Preferably, both of Y 1 and Y 4 are the same one of CR 1 and N, and both of Y 2 and Y 3 are the same and are the other of CR 1 and N. Preferably, the R 1 of each CR 1 is the same.

[0045] In a particularly preferred embodiment, X 1 is a group of formula (II), X 2 is a group of formula (III), each of Y 2 and Y 3 is N, and each of Y 1 and Y 4 is CR 1And in the formula, each R 1 They are preferably the same.

[0046] Preferably, Ar 1 Ar 2 and Ar 3 Each occurrence is independently selected from a 6- to 12-membered arylene group or an optionally condensed 5- or 6-membered heteroarylene group, for example, an uncondensed 5- or 6-membered heteroarylene or a benzene-condensed 5- or 6-membered heteroarylene. Exemplary group Ar 1 Ar 2 and Ar 3 This includes, but is not limited to, a para-phenylene group, a thiophene group, a furan group, and a benzobisoxazole group. Each of these groups may be independently unsubstituted or substituted with one or more substituents. Para-phenylene is preferred.

[0047] m is preferably 1 or more, preferably 2 to 5, and more preferably 2 or 3.

[0048] p and q are preferably 1 or 2, and more preferably 1, independently of each other.

[0049] Ar 1 Ar 2 and Ar 3 Each of these may be independently unsubstituted, or have one or more substituents R 2 It may be replaced with.

[0050] Preferably, R 2 In each appearance, independently, F, CN Sofa NO2, Branched, linear, or cyclic C 1~40 Alkyl alkyl group, preferably C 1~20 Selected from alkyl groups, with one or more non-adjacent C atoms being O, S, NR 5 , SiR 6 2. C may be substituted with O or COO, and in the formula, R5 In each occurrence, H or a substituent, preferably H or C 1~20 It is a hydrocarbon group, and R 6 In each occurrence, the substituents are independent, and C is of any choice. 1~20 It is a hydrocarbyl group, or Unsubstituted or substituted with one or more substituents, aryl group or heteroaryl group Ar 5 The phenyl group is either unsubstituted, or F, CN, NO 2 and branched, linear, or cyclic C 1~20 Alkyl group (wherein the formula one or more non-adjacent C atoms are O, S, NR) 5 , SiR 6 2. Substituting with a substituent selected from (which may be substituted with C=O or COO).

[0051] Preferably, at least one substituent R 2 , each substituent R can be optionally selected 2 C 1~20 Alkyl alkyl group, C 1~20 Alkoxy group, or formula -(Ak 1 ) y -(OCH2CH2) z -Ak 2 It is the basis of, in the formula, Ak 1 is C 1~4 It is an alkylene group, y is 0 or 1, z is 1 to 15, and Ak 2 is C 1~4 It is an alkyl group. More preferably, R 2 C 1~12 Alkyl or C 1~12 It is an alkoxy. 1~12 Alkoxy is particularly preferred.

[0052] Exemplary - (Ar 1 ) m -The base includes, but is not limited to, the bases of formula (IVa) and formula (IVb). [ka]

[0053] In the formula, R2 w is a substituent in each instance, and w is 0 or a positive integer in each instance.

[0054] Preferred - (Ar 1 ) m - The base has formula (IVb-1), Ar 2 and Ar 3 These are preferably substituted or unsubstituted 1,4-phenylene groups, more preferably unsubstituted 1,4-phenylene groups. [ka]

[0055] The polymer is X 1 and a first monomer having two reactive groups, and X substituted with two reactive groups 2 It may also be formed by polymerizing a second monomer having X, where the reactive groups of the first and second monomers react to form X 1 and X 2 Between them, Imin (-CR 1 It forms an N- bond. Suitable reactive groups for forming an imine bond are an aldehyde group or a ketone group (-C(=O)R). 1 ) Reactive groups, preferably aldehyde group reactive groups and amine group (NH2) reactive groups.

[0056] In some embodiments, polymerization is carried out between a first monomer of formula M1 and a second monomer of formula M2. [ka] In the formula, each RG 1 C(=O)R 1 A first reactive group selected from and NH2, where each RG2 is C(=O)R 1 And it is another second reactive molecule of NH2.

[0057] Preferably, each RG 1 C(=O)R 1And each RG 2 It is NH2.

[0058] RG 1 and RG 2 The reaction between may be catalyzed by a Lewis acid. The Lewis acid may be Brønsted-Lowry acid. Exemplary catalysts include sulfonic acids and their salts, such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, and their salts; aromatic alcohols, more preferably substituted with at least one hydroxyl group, and optionally one or more C 1~6 Examples include benzenes substituted with one or more additional substituents, such as alkyl groups.

[0059] An example of a trifluoromethanesulfonate is scandium triflate, or Sc(Trf)3.

[0060] Exemplary aromatic alcohols are unsubstituted or have one or more C 1-6 A phenol substituted with an alkyl group, more preferably one or more methyl groups, such as m-cresol.

[0061] The catalyst may be supplied in an amount of 0.01 to 0.3 molar equivalents relative to the total number of moles of monomer. The catalyst is suitable for dissolving in monomer or in a solvent or solvent mixture in which the monomer is dissolved.

[0062] Optionally, one or more solvents may be selected. 1~12 Alkyl, C 1~12The solvent is selected from alkoxys, benzenes or naphthalenes substituted with one or more substituents selected from F and Cl, ethers, esters, halogenated alkanes, ketones, sulfoxides, and mixtures thereof. Exemplary solvents include, but are not limited to, toluene, xylenes, 1,2,4-trimethylbenzene, mesitylene, tetrahydrofuran, 1-methylnaphthalene, 1-chloronaphthalene, diiodomethane, anisole, N-methylpyrrolidone, 1,2-dimethoxybenzene, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, and cyclopentanone.

[0063] The polymers described herein are preferably at least partially crystalline.

[0064] The polymers described herein are preferably linear (unbranched) polymers. The linear polymers are the two reactive matrix groups RG described herein. 1 A monomer having two reactive RG groups 2 It can be formed by reaction with monomers having [specific properties].

[0065] The polymers described herein may undergo pi-pi stacking when deposited as films.

[0066] Optionally, the thermal conductivity of the polymers described herein is at least 0.5 Wm². -1 K -1 Optionally, at least 0.6 or 0.7 Wm -1 K -1 That is the case.

[0067] The number-average molecular weight (Mn) of the polymers described herein, as measured by gel permeation chromatography, is approximately 1 x 10⁻⁶. 3 ~1x10 8 Preferably 1x10 4 ~5x10 6 The range may also be . The average molecular weight (Mw) of the polymers described herein on a polystyrene basis is 1 x 10 3 ~1x10 8Preferably 1x10 4 ~1x10 7 That's fine.

[0068] Polymer treatment The formation of a film containing the polymer described herein may involve forming a precursor film containing monomers constituting the polymer, and then polymerizing the monomers. The polymerization method will hereafter be referred to as in-situ polymerization. The precursor film may consist of monomers that form the polymer, or the precursor film may be a composition containing one or more further materials, such as the catalyst described herein and / or thermally conductive particles such as boron nitride particles.

[0069] Preferably, the formation of a film containing the polymer described herein involves depositing a polymer formulation in which the polymer is dissolved or dispersed in one or more solvents. The formulation may consist of the polymer and one or more solvents, or it may be a composition containing one or more further materials such as the catalyst described herein and / or thermally conductive particles such as boron nitride particles. The inorganic thermally conductive particles such as boron nitride described herein may be substituted with organic groups, or optionally aromatic groups, such as oligo(hetero)arylene or poly(hetero)arylene containing 1 to 10 arylene groups or heteroarylene groups. Exemplary surface groups are oligophenylenes, such as biphenyl or terphenyl. Surface groups of thermally conductive particles are disclosed in International Publication No. WO2022 / 207695, the contents of which are incorporated herein by reference.

[0070] In some preferred embodiments of in-situ polymerization, the formation of a precursor film involves the deposition of a monomer formulation containing monomers dissolved in one or more solvents. According to these embodiments, in-situ polymerization is preferably carried out in a solvent. The monomer formulation may or may not contain a catalyst.

[0071] The solvent for the monomer or polymer formulation may be selected based on its ability to dissolve the monomer or polymer. Exemplary solvents are optionally C 1~12 Alkyl, C 1~12 This includes, but is not limited to, alkoxys, benzenes or naphthalenes substituted with one or more substituents selected from F and Cl, ethers, esters, halide alkanes, ketones, sulfoxides, and mixtures thereof. Exemplary solvents include, but are not limited to, toluene, xylenes, 1,2,4-trimethylbenzene, mesitylene, 1-methylnaphthalene, 1-chloronaphthalene, diiodomethane, anisole, tetrahydrofuran, N-methylpyrrolidone, 1,2-dimethoxybenzene, dityl sulfoxide, 1,3-dimethyl-2-imidazolidinone, and cyclopentanone.

[0072] The concentration of each monomer or polymer 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. The monomer or polymer formulation may be heated to achieve dissolution of one or more monomers or polymers.

[0073] 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 about 100°C or less, optionally between 50 and 90°C. After drying, the film may be heated to a temperature above 100°C, optionally between 100 and 200°C. The temperature applied before, during, or after drying may be 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 with the lowest melting point.

[0074] In a preferred embodiment 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 film is heated to at least the melting point of the monomers, or, if multiple monomers are present, to the melting point of the monomer with the lowest melting point. Optionally, the polymer precursor film is heated below the melting point of the lowest monomer to remove the liquid component, and then the temperature is raised to at least this melting point. It will be understood that the amount and / or properties of the liquid are set so that the monomer particles do not dissolve in the liquid. Preferably, each monomer is sparingly soluble or insoluble in the liquid. The liquid is a single liquid material or a mixture of two or more liquid materials, for example, water and C 1~6 The monomer formulation in these embodiments may be, for example, a suspension or a paste, and an appropriate deposition method may be selected accordingly.

[0075] The monomer or polymer formulations described herein may be deposited by suitable solution deposition techniques, including but not limited to spin coating, dip coating, jet dispensing, drop casting, spray coating, and blade coating.

[0076] In some embodiments, films formed by in-situ polymerization or deposition of polymer formulations containing pre-formed polymers can be formed directly on the surface of a device or apparatus and used as a heat transfer film without further processing of the film.

[0077] In other embodiments, a polymer film may be formed by in-situ polymerization, deposition of a pre-formed polymer, or other methods, and then the polymer film may be processed using a heat treatment technique to form a heat transfer film on the surface of a device or apparatus. Exemplary heat treatment techniques include, but are not limited to, extrusion molding, injection molding, thermocompression bonding, and melt press molding or melt press molding.

[0078] The thermally conductive film may be composed of a polymer or may contain one or more further materials, optionally one or more amorphous polymers, such as polystyrene, polyethylene, polypropylene, and / or one or more thermally conductive materials, such as boron nitride.

[0079] In some embodiments, the film contains thermally conductive particles, such as boron nitride, dispersed therein. In some embodiments, the film does not contain any thermally conductive particles.

[0080] Optionally, the thickness of the thermally conductive film containing or comprising a polymer as described herein is in the range of 1 to 100 micrometers, preferably 10 to 100 micrometers.

[0081] Purpose Films containing the polymers described herein can be used in any known application of thermally conductive films. For example, 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 in any known thermal interface control application.

[0082] In this arrangement, it is understood that the film is configured to transfer heat from a heating device to a heat transfer device. Preferably, the film has a first surface that is in direct contact with the surface of the heating device, and / or a second surface opposite the first surface that is in direct contact with the surface of the heat transfer device.

[0083] The heating device may also be an electronic device.

[0084] 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 including one or more heat dissipation features provided with fins or 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 due to heat absorption.

[0085] Preferably, the film is a thermal conductive layer for an electronic device.

[0086] 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 may be separated from the surface by one or more thermally conductive layers.

[0087] The film described herein may be placed on the surface of the heatsink opposite to the surface of the heatsink from which the fins extend. During use, the film may be placed between the heatsink and the electrical components.

[0088] The film described herein may be a heat spreader layer placed on the surface of a printed circuit board, for example, a PCB used in an LED array.

[0089] The films described herein include, but are not limited to, non-conductive films for flip chips, such as underfills, including 3D stacked multichips.

[0090] The electronic device shown in Figure 1 includes 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 containing or consisting of a polymer described herein fills the area between the chip 105 and the substrate 101. Optionally, the polymer is crosslinked.

[0091] Referring to Figure 2A, in some embodiments, the formation of an electronic device involves forming interconnects 107 from conductive bumps 107' (e.g., solder bumps) by bringing them into contact with conductive pads 103 placed on a substrate 101 (e.g., a printed circuit board). The formation of the polymer-containing underfill 109 described herein involves applying a formulation containing one or more monomers within the overlap region between the chip 105 and the substrate 101. Optionally, the polymer is crosslinked, for example, by heat and / or UV treatment after the application of the formulation and the reaction of one or more monomers.

[0092] 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 illustrates complete coverage of the conductive bumps 107', but it is understood that the conductive bumps 107' may be partially covered such that a portion of the conductive bumps 107' protrudes from the surface of the film 109. The conductive bumps 107' are then brought into contact with a conductive pad 103 placed on a substrate 101 (e.g., a printed circuit board) to form a conductive interconnect between the substrate and the chip. Formation of the conductive interconnect may include the application of heat and / or pressure.

[0093] If the polymer of film 109 is crosslinked, the crosslinking may be performed before, during, or after contacting the conductive bump 107' with the conductive pad 103.

[0094] Two or more chips may be connected to a film containing a polymer described herein, which is placed between the chips. Figure 3 shows a 3D stack of chips 105 according to several embodiments, where the chips 105 are sandwiched between an interposer 111 and nonconductive 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 nonconductive film 109 contains a polymer described herein. Through-vias 115 are formed through the chips 105 and the interposer. The 3D stack may include a heat sink 113 placed on its surface.

[0095] In some embodiments, a film comprising or consisting of the polymer described herein may be placed between an electronic device and a heat sink. [Examples]

[0096] Polymer formation The polymer was formed by reacting 2',5'-dihexyloxyterphenyl-4,4"-dialdehyde (aldehyde monomer 1) with the diamine monomer shown below. [ka] [Table 1]

[0097] Synthesis of Polymer 1 in Example m-cresol (2 eqv) was added to a mixture of monomer B1 (0.288 mg, 1 eqv) and monomer A1 (0.5 g, 1.1 eqv) in toluene (5 ml) and THF (50 ml). The mixture was stirred at room temperature for 30 minutes, then concentrated under vacuum until dry, producing a yellow oily substance which was left to stand and solidification began. This product was resuspended in toluene / THF (approximately 50 mL), stirred for 5 minutes, and then concentrated again until dry. This process was repeated, and the resulting solid was suspended in warmed dichloromethane (DCM) and precipitated in methanol. The product was recovered as a yellow powdery solid. Yield = 66%.

[0098] Synthesis of Polymer 2 (Example) m-cresol (2 eqv) was added to a mixture of monomer B2 (430 mg, 1 eqv) and monomer A1 (1.0 g, 1.1 eqv) in toluene (5 ml) and THF (50 ml). The mixture was stirred at room temperature for 30 minutes, then concentrated under vacuum until dry, producing a yellow oily substance which was left to stand and solidification began. This was resuspended in toluene / THF (approximately 50 mL), stirred for 5 minutes, and then concentrated again until dry. This process was repeated, and the resulting solid was dissolved in warmed DCM and precipitated in methanol. The product was recovered as a yellow powdery solid. Yield = 86%.

[0099] Synthesis of Polymer 3 in Example m-cresol (2 eqv) was added to a mixture of monomer B3 (424 mg, 1 eqv) and monomer A1 (1.0 g, 1.1 eqv) in toluene (5 ml) and THF (50 ml). The mixture was stirred at room temperature for 30 minutes, then concentrated under vacuum until dry, producing a yellow gel-like substance. This product was resuspended in toluene (50 mL), stirred for 5 minutes, and then concentrated again until dry. This process was repeated, and the resulting solid was dissolved in DCM and precipitated in methanol. The product was recovered as a yellow powder. Yield = 71%.

[0100] Synthesis of Polymer 4 in Example m-cresol (2 eqv) was added to a mixture of monomer B4 (532 mg, 1 eqv) and monomer A1 (1.0 g, 1.1 eqv) in toluene (5 ml) and THF (50 ml). The mixture was stirred at room temperature for 1 hour, then concentrated under vacuum until dry, producing a yellow oily substance which was left to stand and solidification began. This product was resuspended in toluene (approximately 50 mL), stirred for 5 minutes, and then concentrated again until dry. After repeating this process, the resulting solid was suspended in a DCM / toluene mixed solvent and precipitated in methanol. The product was recovered as a yellow powdery solid. Yield = 42%.

[0101] Synthesis of Polymer 5 (Example) m-cresol (2 eqv) was added to a mixture of monomer B5 (536 mg, 1 eqv) and monomer A1 (1.0 g, 1.1 eqv) in toluene (5 ml) and THF (50 ml). The mixture was stirred at room temperature for 30 minutes, then concentrated under vacuum until dry, producing a yellow oily substance which was left to stand and solidification began. This was resuspended in toluene (approximately 50 mL), stirred for 5 minutes, and then concentrated again until dry. After repeating the process, the resulting solid was suspended in warm DCM and precipitated in methanol. The product was recovered as a yellow powdery solid. Yield = 70%.

[0102] Film accumulation The polymer ink is prepared by dissolving the polymer in o-dichlorobenzene at a concentration of 20 mg / mL, and optionally, the mixture may be heated to 80°C to facilitate dissolution.

[0103] Film formation After dissolving the polymer in a solvent, the resulting ink was immediately drop-cast onto the substrate used for measuring thermal conductivity at a temperature of 80°C. A 0.5 mm thick fluorosilicone rubber sheet gasket (manufactured by Silex Silicones Ltd.) mounted on the substrate was used to restrict the ink to a specified area (18 mm x 10 mm rectangle) during the drop-casting process. The drop-cast solution was held at 80°C for 30 minutes, after which heating was stopped and the solution was allowed to cool to room temperature. No further annealing step was performed after the solvent evaporation of the drop-cast thin film.

[0104] Measurement of thermal conductivity The sensor substrate 600 (approximately 25 mm x 25 mm) shown in Figure 4 was used for the thermal conductivity measurement described herein. The substrate has a polyethylene naphthalate (PEN) film (Dupont Teonex Q83, 25 μm) including a 200 nm thick heating structure consisting of a 20 micrometer wide heater wire 610, a 500 micrometer wide busbar 620 for current application, and a contact pad 640. The detection structure is very similar to the heating structure, except that the heater wire is replaced by a 200 micrometer wide sensor line 630.

[0105] Referring to Figures 5A and 5B, the sensor substrate 600, which carries the film to be measured, is placed on a temperature-controlled aluminum block and its temperature is adjusted by a system PID so that it can be controlled by software. 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 wire 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 cutout matching the notch cutout of the aluminum block 710 is placed on top, and a plain PMMA sheet 740 (4 mm thick) is placed on top to seal the device. The entire assembly is secured by bolts and nuts at position 750. The heater wire is connected to a source meter unit (Keithley 2400) using a 4-wire measurement setting. The sensor wire is connected to a multimeter unit (Keithley 2000) using a 4-wire setting.

[0106] The assembly's temperature is first stabilized at a predetermined temperature. Then, the resistance of the heater wire and temperature sensor is measured. To measure the heater wire's resistance without causing excessive heating, a low current is supplied, and the voltage is measured in short pulses with intervals between pulses to allow heat dissipation. Next, a constant DC current is passed through the heater wire to induce resistive heating. Due to the arrangement of the substrate within the assembly, the heat flows through the substrate and film to the aluminum block acting as a heat sink, establishing an approximate one-dimensional steady-state heat flux. In this state, the power dissipated in the heater wire and the resistance of the heater wire and temperature sensor are further measured. This process is repeated as the supplied current increases, and the complete process is repeated at the next temperature setpoint.

[0107] The resistance of the heater wire and sensor line under no-heat-flux conditions at different temperature setpoints can be used as calibration data in the linear fit of resistance and temperature to determine the temperature of the resistive element under steady-state heat flux conditions. Therefore, the temperature gradient ΔT between the heater wire and the temperature sensor (aligned with the heat sink) can then be calculated. It is assumed that the power dissipated in the heater wire is completely converted into thermal energy Q. A linear fit is then performed between dT and Q using further parameters for the length of the heater wire (L, 14.4 mm), the distance between voltage detection points, and the gap width (2w, 1 mm) for measuring power. This provides a measurement of the conductance C of the device under test, which is affected by conductive heat transfer within the substrate and losses associated with convective and radiant heat transfer (h) to the environment.

[0108] To calculate the thermal conductivity k, the same measurement process is performed on a substrate (substrate only) without any test film. It is assumed that the losses when measuring a coated substrate and an uncoated substrate are approximately the same. Device measurement value (C F+S ) from the conductance (C) of the substrate S Subtract the pre-thermal conductivity (k) to adjust for these losses. Then, the pre-thermal conductivity (k) F ) and the conductance of only the resulting film is taken as the film thickness (d F The calculation is performed by dividing by ). The film thickness is determined by measuring the total thickness using a digital micrometer and subtracting the substrate thickness.

number

[0109] The results are shown in Table 1. [Table 2]

[0110] The phase transition temperature was determined using a melting point analyzer configured to detect changes in the transmittance of the sample while heating the sample inside the tube. The ranges listed in Table 1 represent the temperature at which the sample begins to change from a powder state to a liquid or glossy substance, as confirmed by observing a video of the sample, up to the temperature at which it becomes a clear liquid.

[0111] As shown in Table 1, comparative polymer 1 has the highest thermal conductivity among the polymers listed in the table, but it also has a higher melting point, and therefore is not suitable for processing using the heat treatment techniques described herein.

[0112] Polymer Examples 1 and 2 exhibit an excellent combination of a lower onset phase transition temperature and good thermal conductivity. The data in Table 1 suggest that even lower melting points can be achieved by providing chains L with three or four atomic lengths. Surprisingly, it was found that the thermal conductivity improved by including oxygen in the chain for a given chain length of chain L.

[0113] Furthermore, although we do not wish to be subject to theoretical constraints, polymers containing an odd number of chain atoms in chain L may pack in a different way than polymers containing an even number of chain atoms in chain L.

[0114] Film formation conditions After drop-casting a polymer solution onto a substrate fitted with a fluorosilicone rubber sheet gasket, the substrate was held on a hot stage at 80°C for 30 minutes, after which heating was stopped. Since this temperature is close to the polymer's initial phase transition point, it is believed that chain motion is promoted at this temperature, resulting in the formation of a more uniform thin film.

[0115] The film of Polymer Example 2 was prepared by the same method, but differed in that after being held at 80°C for 30 minutes, it was removed without contact with the heated surface and rapidly cooled to room temperature.

[0116] Referring to Figures 6A and 6B, this rapid cooling resulted in a film with large domains within the polymer film. In contrast, as shown in Figures 7A and 7B, the slow cooling treatment described above yielded a more uniform film. While not intended to be constrained by any theory, slow cooling at the phase transition onset temperature allows for optimal orientation of the polymer film.

Claims

1. A polymer containing repeating units of formula (I), 【Chemistry 1】 During the ceremony, X １ and X ２ These are selected independently from equation (II) and equation (III), but X １ and X ２ At least one of them is a base of equation (III), 【Chemistry 2】 In the formula, Ar １ Ar ２ and Ar ３ In each occurrence, is independently an arylene group or a heteroarylene group, m is at least 1, p is at least 1, q is at least 1, and L is optionally a chain substituted with a methylene group and an O atom. Y １ and Y ２ One of them is CR １ wherein, R １ is H or a substituent, and Y １ and Y ２ the other one of them is N, and Y ３ and Y ４ One of them is CR １ and Y ３ and Y ４ The other one of them is a polymer, N.

2. Each R １ is H or C １～２０ The polymer according to claim 1, wherein the hydrocarbyl group is...

3. L is Ar ２ and Ar ３ The polymer according to claim 1 or 2, comprising at least three atoms that separate and .

4. Ar ２ and Ar ３ The polymer according to any one of the preceding claims, wherein each of the atoms of L bonded to it is O.

5. X １ and X ２ One of them is the basis of equation (II), and X １ and X ２ The polymer according to any one of the preceding claims, wherein the other of the is a group of formula (III).

6. The polymer according to claim 5, wherein m is at least 2.

7. Y １ and Y ４ Both are CR １ and the same one of N, and Y ２ and Y ３ Both are the same, CR １ The polymer according to any one of the preceding claims, wherein N is the other one of the two.

8. Ar １ Ar ２ and Ar ３ The polymer according to any one of the preceding claims, wherein each occurrence is independently selected from a 6- to 12-membered ring arylene group or optionally condensed 5- or 6-membered ring heteroarylene group.

9. Ar １ Ar ２ and Ar ３ The polymer according to any one of the preceding claims, wherein each occurrence is independently an unsubstituted or substituted para-phenylene group.

10. The polymer according to any one of the preceding claims, wherein p and q are preferably each 1.

11. A method for forming the polymer according to any one of the preceding claims, comprising reacting a first monomer of formula M1 with a second monomer of formula M2, 【Transformation 3】 In the formula, each RG １ C(=O)R １ and NH ２ A first reactive group selected from, where each RG2 is C(=O)R １ and NH ２ A method, which is one of the other two reactive groups.

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

13. A method for forming the film according to claim 12, wherein the film is formed by a heat treatment method.

14. The method according to claim 13, wherein the heat treatment method is selected from extrusion molding, injection molding, thermocompression bonding, and hot press molding or melt press molding.

15. The method according to claim 13 or 14, comprising depositing the polymer on a surface, heating the deposited polymer to a temperature above its phase transition temperature, and cooling the polymer to a temperature below its phase transition temperature at a rate of 2°C per minute or less.

16. An electronic device comprising the film according to claim 12, disposed on the surface of a functional layer of the electronic device.

17. The electronic device according to claim 16, 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.

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

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

20. An apparatus comprising: a heating device; a heat transfer device configured to transfer heat from the heating device; and a film according to claim 12 disposed between the heating device and the heat transfer device.

21. A heat sink comprising a first surface and a second surface on the opposite side, wherein the first surface has fins extending therefrom, and the second surface has the film according to claim 12 disposed thereon.

22. A formulation comprising a first monomer of formula M1 and a second monomer of formula M2, dissolved or dispersed in a solvent or solvent mixture, 【Chemistry 4】 wherein X １ and X ２ are as defined in claim 1 or 5, and each RG １ is a first reactive group selected from C(=O)R １ and NH ２ and each RG ２ is the other one of C(=O)R １ and NH ２ which is a second reactive group, a formulation.

23. A method for forming a polymer, comprising reacting a polymerization mixture containing a first monomer of formula M1 and a second monomer of formula M2, 【Transformation 5】 In the formula, each RG １ C(=O)R １ and NH ２ A first reactive group selected from each RG ２ C(=O)R １ and NH ２ The other second reactive group among them is R １ is H or a substituent, and X ３ and X ４ These are independently selected from the bases of equation (II) and equation (III), 【Transformation 6】 In the formula, Ar １ Ar ２ and Ar ３ In each occurrence, independently, is an arylene group or a heteroarylene group, m is at least 1, p is at least 1, q is at least 1, and L' is optionally substituted C １～１０ It is an alkylene group, and one or more non-adjacent C- atoms are O, S, NR ５ , SiR ６ ２ C may be substituted with O or COO, and in the formula R ５ In each occurrence, is H or a substituent, and R ６ Each instance is independently a substituent, A method wherein the polymerization mixture comprises a solvent or solvent mixture in which a first monomer, a second monomer, and an aromatic alcohol are dissolved.

24. The method according to claim 23, wherein the aromatic alcohol is a benzene substituted with at least one hydroxyl group.

25. The method according to claim 23 or 24, wherein the solvent or solvent mixture comprises alkylated benzene.

26. The method according to any one of claims 23 to 25, wherein the solvent or solvent mixture comprises tetrahydrofuran.

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