Polyimide resin and use thereof

Abstract

A polyimide resin and the use thereof. The polyimide resin has a structure as represented by formula I. In the polyimide resin, due to the introduction of an amide structure or a nitro group, the intermolecular force is increased by means of a large number of hydrogen bonds, thereby increasing the glass transition temperature (Tg) of the polymer material; and an ether bond is introduced via R1 to enhance the adhesion between the material and a substrate, thereby avoiding a decrease in the adhesion due to increased Tg. By introducing an amide bond, a nitro group and an ether bond into the polyimide resin, the ultraviolet absorption of the material exhibits a red shift, resulting in stronger absorption at wavelengths of 300 nm or more, and making the material compatible with processes performed at a wavelength of 355 nm. When used in a transfer adhesive, the polyimide resin can ensure better temperature resistance and a high transfer yield of the transfer adhesive; and the polyimide resin is compatible with a 355-nm laser ablation process, requires lower laser energy, causes less damage to a chip, and leaves no adhesive residue.

Description

Polyimide resin and application thereof

[0001] This application claims priority to the Chinese patent application No. 202411134569.7 filed on August 16, 2024 with the Chinese Patent Office, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application belongs to the technical field of mass transfer, for example, a polyimide resin and application thereof. BACKGROUND

[0003] In mass transfer, the surface of a Sapphire substrate (containing a Light-Emitting Diode, LED) is pasted with a transfer release tape (including a transfer tape and a carrier 1), a laser irradiates the LED through the Sapphire substrate; after laser irradiation, the LED is separated from the Sapphire substrate, the whole piece is peeled off the Sapphire substrate, and the LED is adhered to the fixed position of the transfer tape; after alignment, the laser irradiates the transfer release tape through the carrier 1, which absorbs light energy and sublimates and gasifies, and the LED falls on the designated position of the receiving tape (including a receiving tape and a carrier 2); the receiving tape is aligned with a Thin Film Transistor (TFT) backplane, the laser irradiates the receiving tape through the carrier 2, which absorbs light energy and sublimates and gasifies, and the LED falls on the designated position of the backplane (sub-pixel position), and subsequent processes are performed.

[0004] However, the process after the LED is separated from the Sapphire substrate in the mass transfer process involves high temperature, the existing transfer tape has a too low Tg, and the high-temperature process causes the transfer tape to deform under heat, resulting in changes in the position of the chip. In addition, the existing transfer tape has insufficient specific range wavelength absorption, which leads to incomplete ablation and gasification of the transfer tape, so that there are residual glue or carbon particles near the pin of the chip after laser ablation of the transfer tape, affecting the transfer yield, causing great damage to the chip, and affecting the quality of the chip.

[0005] SUMMARY

[0006] The present application provides a polyimide resin and application thereof.

[0007] In a first aspect, the present application provides a polyimide resin, which has a structure shown in Formula I:

[0008] wherein R1 is Y1 is an ether or thioether group, and Y2 is absent or selected from C1-C5 linear or branched alkyl, carbonyl, C1-C5 alkyl-carbonyl, ether group or thioether group;

[0009] R2 is selected from X is selected from an ether group, a thioether group, a C1-C10 linear or branched alkyl group, a carbonyl group or a C1-C5 linear or branched alkyl-carbonyl group, R3 and R4 are independently selected from a nitro group or R7 is selected from an alkenyl group or an alkynyl group; R5 and R6 are independently selected from halogen, C1-C5 alkyl, C3-C6 cycloalkyl, C1-C5 alkoxy, C6-C12 aryl or C3-C12 heteroaryl;

[0010] n is selected from an integer from 100 to 500, n1, n2, n3 and n4 are independently selected from an integer from 0 to 4, and n1 and n3 are not simultaneously 0, and n1+n3≤4, n2+n4≤4.

[0011] In a second aspect, the embodiments of the present application provide a transfer adhesive, wherein the transfer adhesive comprises the polyimide resin according to the first aspect.

[0012] In a third aspect, the embodiments of the present application provide an accepting adhesive, wherein the accepting adhesive comprises the polyimide resin according to the first aspect.

[0013] In a fourth aspect, the embodiments of the present application provide a use of the polyimide resin according to the first aspect, the transfer adhesive according to the second aspect or the accepting adhesive according to the third aspect in mass transfer.

[0014] In a fifth aspect, the embodiments of the present application provide a mass transfer method, wherein the mass transfer method comprises using the polyimide resin according to the first aspect as a transfer adhesive.

[0015] In the present application, due to the introduction of amide structure or nitro group, the intermolecular force is increased by a large number of hydrogen bonds, the glass transition temperature Tg of the polymer material is improved, the adhesion between the material and the substrate is enhanced by introducing ether bond by R1, the influence of adhesion decline caused by Tg improvement is avoided, and the introduction of amide bond and the introduction of nitro group and ether bond in the polyimide resin of the present application cause the red shift of ultraviolet absorption of the material, so that it has stronger absorption above 300 nm wavelength, which can meet the process of 355 nm wavelength.

[0016] The polyimide resin of the present application has a higher glass transition temperature, has stronger absorption above 300 nm wavelength, and can meet the process of 355 nm wavelength. When the polyimide resin of the present application is used as a transfer adhesive, the temperature resistance of the transfer adhesive can be better, the subsequent process has more options, and the transfer yield is high. It can correspond to 355 nm laser wavelength ablation process, the laser energy is small, the damage to the chip is smaller, and there is no residual adhesive. BRIEF DESCRIPTION OF DRAWINGS

[0017] FIG. 1 is a schematic diagram of a mass transfer process flow.

[0018] Reference signs:

[0019] Wherein 1 is a sapphire substrate, 2 is a transfer adhesive, 3 is a first carrier, 4 is an adhesive, 5 is a second carrier, and 6 is a back plate. DETAILED DESCRIPTION

[0020] The technical solutions of the present application will be described below through specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present application.

[0021] The polyimide resin provided by the embodiments of the present application has a structure shown in Formula I:

[0022] Wherein R1 is Y1 is an ether or thioether group, and Y2 is absent or selected from C1-C5 linear or branched alkyl, carbonyl, C1-C5 alkyl-carbonyl, ether group or thioether group;

[0023] R2 is selected from X is selected from an ether group, a thioether group, C1-C10 linear or branched alkyl, carbonyl or C1-C5 linear or branched alkyl-carbonyl, R3 and R4 are independently selected from a nitro group or R7 is selected from alkenyl or alkynyl; R5 and R6 are independently selected from halogen, C1-C5 alkyl, C3-C6 cycloalkyl, C1-C5 alkoxy, C6-C12 aryl or C3-C12 heteroaryl;

[0024] n is selected from an integer from 100 to 500, n1, n2, n3 and n4 are independently selected from an integer from 0 to 4, n1 and n3 are not simultaneously 0, and n1+n3≤4, n2+n4≤4.

[0025] In the present application, due to the introduction of amide structure or nitro group, the intermolecular force is increased by a large number of hydrogen bonds, the glass transition temperature Tg of the polymer material is improved, the adhesion between the material and the substrate is enhanced by introducing ether bond by R1, the influence of adhesion decline caused by Tg improvement is avoided, and the introduction of amide bond with unsaturated group (i.e. alkenyl or alkynyl) and the introduction of nitro group and ether bond in the polyimide resin of the present application cause the red shift of ultraviolet absorption of the material, so that it has stronger absorption above 300 nm wavelength, which can meet the 355 nm wavelength process.

[0026] When the polyimide resin of the present application is used for transfer adhesive, it can ensure better temperature resistance of the transfer adhesive, has large process selection, and has high transfer yield; it can correspond to 355 nm laser wavelength ablation process, has small laser energy, causes less damage to the chip, and has no residual adhesive.

[0027] In this application, C1-C5 can be C1, C2, C3, C4 or C5; C1-C10 can be C1, C2, C3, C4, C5, C6, C7, C8, C9 or C10; C3-C6 can be C3, C4, C5 or C6; C6-C12 can be C6, C7, C8, C9, C10, C11 or C12; C3-C12 can be C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12.

[0028] In this application, n is selected from an integer between 100 and 500, such as 100, 103, 105, 108, 110, 120, 130, 240, 150, 170, 190, 200, 220, 240, 250, 280, 300, 320, 350, 380, 400, 420, 450, 480, or 500. In this application, n represents the number of repeating units in Equation I.

[0029] In this application, n1, n2, n3 and n4 are independently selected from integers from 0 to 4, such as 0, 1, 2, 3 or 4.

[0030] In this application, n1 and n3 are not both 0. In this application, by introducing an amide structure or a nitro group into the structure shown in Formula I, more hydrogen bonds can be present in the polyimide resin structure, thereby increasing the intermolecular forces and raising the glass transition temperature of the polymer material.

[0031] In this application, n1+n3≤4, for example, n1+n3 can be 0, 1, 2, 3, 4, and n2+n4≤4, for example, n2+n4 can be 0, 1, 2, 3, 4.

[0032] In this application, R1 is Y1 is an ether or thioether group, and Y2 is absent or selected from C1-C5 straight-chain or branched alkyl, carbonyl, C1-C5 alkyl-carbonyl, ether, or thioether groups. In this application, Y1 in R1 is an ether or thioether group, and Y2 may be absent or any of the groups mentioned above. When Y2 is absent, it means that there is no connecting bond at Y2, i.e., R1 is...

[0033] In some embodiments, the ether group is selected from -O-, Where m and p are independent integers from 1 to 5, such as 1, 2, 3, 4 or 5.

[0034] In some embodiments, the thioether group is selected from -S-, Where m1 and p1 are independent integers from 1 to 5, such as 1, 2, 3, 4 or 5.

[0035] In some embodiments, R1is wherein Y3is selected from O or S, Y4is selected from C1-C5 linear or branched alkyl, carbonyl, C1-C5 alkyl-carbonyl, ether group or thioether group, m2is selected from an integer from 1-5.

[0036] In some embodiments, Y4is selected from -O-, -S-, carbonyl,

[0037] In some embodiments, R1is

[0038] In R2of the present application, n1and n3are not simultaneously 0, so that R2includes at least one R3or R4group, so that it contains a nitro group or structure, i.e. introducing a nitro group or an amide structure with α,β-unsaturated group in the structure of the polyimide resin, so that the ultraviolet absorption of the material is red-shifted, and it has stronger absorption above 300 nm wavelength, which can meet the process of 355 nm wavelength.

[0039] In some embodiments, X is selected from -CH2-, -O-, -S-, m, p, m1and p1are independently an integer from 1-5, for example 1, 2, 3, 4 or 5.

[0040] In some embodiments, the alkenyl group is selected from C2-C8 alkenyl group, for example C2, C3, C4, C5, C6, C7or C8 alkenyl group, and specific examples can be and the like, and the wavy line represents the connecting site of the group.

[0041] In some embodiments, the alkynyl group is selected from C2-C8 alkynyl group, for example C2, C3, C4, C5, C6, C7or C8 alkynyl group, and examples can be and the like, and the wavy line represents the connecting site of the group.

[0042] In some embodiments, the R7is selected from and the like, and the wavy line represents the connecting site of the group.

[0043] In some embodiments, R3and R4are independently selected from nitro group,

[0044] In some embodiments, R3and R4are selected from the same group. When R3and R4are selected from the same group, the molecular structure is more symmetric, has greater intermolecular forces, and can further increase the Tg of the final material.

[0045] In some embodiments, R5and R6are independently selected from hydrogen, F, Cl, Br, methyl, ethyl, isopropyl, pentyl, cyclopropyl, cyclohexyl, methoxy, ethoxy, phenyl, biphenyl, naphthyl, pyridyl, furanyl, triazinyl, benzofuranyl, or dibenzofuranyl.

[0046] In the structure of R2of the present application there can be a case containing only R3substituent, or a case containing only R4substituent, or a case containing both R3and R4substituents but not containing R5and R6substituents, or a case containing both R3and R4and containing at least one of R5and R6.

[0047] In some alternative embodiments, R2is selected from R3, R4, X, n1, and n2are defined as described above.

[0048] In some alternative embodiments, R2is selected from R3, R4, X are defined as described above.

[0049] In some alternative embodiments, R2is selected from X is defined as described above.

[0050] In some embodiments, the polyimide resin has any one of the following structures of Formula II-VI:

[0051] wherein n and X are defined as described above.

[0052] In some embodiments, the polyimide resin is any one of the following compounds:

[0053] wherein n is selected from an integer of 100-500.

[0054] The embodiments of the present application provide a transfer adhesive, which comprises the polyimide resin as described above.

[0055] The polyimide resin of the present application can ensure better temperature resistance of the transfer adhesive, has large process selection and high transfer yield, can correspond to 355 nm laser wavelength ablation process, has small laser energy and causes less damage to the chip, and has no residual adhesive.

[0056] The present application provides a receiving adhesive comprising the polyimide resin as described above.

[0057] The present application provides an application of the polyimide resin as described above or the transfer adhesive as described above or the receiving adhesive as described above in mass transfer.

[0058] The present application provides a mass transfer method comprising using the polyimide resin as described above as a transfer adhesive.

[0059] The mass transfer method can comprise the following steps:

[0060] As shown in FIG. 1, by attaching a transfer release adhesive tape (including a transfer adhesive 2 and a first carrier 3) to the surface of a Sapphire substrate 1 (containing an LED), a laser is irradiated on the LED through the Sapphire substrate; after laser irradiation, the LED is separated from the Sapphire substrate, the whole piece is peeled off the Sapphire substrate, and the LED is adhered to the fixed position of the transfer release adhesive tape; after transfer alignment, the laser is irradiated on the transfer release adhesive through the first carrier 3, which absorbs light energy and sublimates and gasifies, and the LED falls on the designated position of the receiving adhesive tape (including a receiving adhesive 4 and a second carrier 5); the receiving adhesive tape is aligned with a TFT back plate 6, the laser is irradiated on the receiving adhesive through the second carrier 5, which absorbs light energy and sublimates and gasifies, and the LED falls on the designated position (sub-pixel position) of the back plate, and then subsequent processes are performed; wherein the polyimide resin described in the present application is used as a transfer adhesive.

[0061] In the present application, the first carrier and the second carrier can be selected from commonly used transparent substrates such as polyethylene terephthalate (PET).

[0062] In the present application, when the polyimide resin is used as a transfer adhesive, the receiving adhesive can be selected from one or a combination of at least two of organic silicone resin, polyimide resin, acrylic resin or polyurethane resin.

[0063] The following exemplary preparation examples of the polyimide resin described in the present application are listed:

[0064] Example 1

[0065] The present application provides a polyimide with the following structure:

[0066] wherein X is an oxygen atom.

[0067] The preparation method comprises the following steps:

[0068] (1) Preparation of diamine monomer

[0069] Under a nitrogen atmosphere, 200 mL of tetrahydrofuran (THF) solvent, triethylamine and 3,3,4,4-tetraaminodiphenyl ether in a molar ratio of 1:1 were added to a three-necked flask, 1.1 equivalents of 2-butenoyl chloride was slowly added dropwise in an ice water bath, the reaction was stirred for 2 h, the precipitate was removed by filtration, the reaction solution was separated by column chromatography, concentrated, and recrystallized to obtain product A.

[0070] (2) Preparation of polyamic acid

[0071] In a three-necked flask, acid anhydride B and product A were added in a molar ratio of 1:1, and the reaction was stirred in dimethylacetamide solvent at room temperature for 9 h to obtain a polyamic acid precursor, and n was 100-200.

[0072] (3) Preparation of polyimide

[0073] The polyamic acid was dissolved in dimethylacetamide to obtain a precursor solution with a mass percentage concentration of 45%, which was coated into a film, the solvent was dried by heating to 180°C, 200°C was maintained for 3 h, 260°C was maintained for 5 h, 230°C was maintained for 3 h, and the room temperature was slowly recovered to obtain a polyimide product, which was tested to have a glass transition temperature (Tg) of 290°C and an ultraviolet absorption cutoff wavelength of 320 nm. The glass transition temperature (Tg) was tested by TA DMA 850, and the ultraviolet absorption test used Aglient 8453.

[0074] Example 2

[0075] This example provides a polyimide with the following structure:

[0076] wherein X is a sulfur atom.

[0077] The synthesis method is the same as that of Example 1, and the raw material 3,3,4,4-tetraaminodiphenyl ether is replaced by 3,3,4,4-tetraaminodiphenyl sulfide.

[0078] A polyimide product was obtained, which had a glass transition temperature of 280°C and an ultraviolet absorption cutoff wavelength of 330 nm.

[0079] Example 3

[0080] This example provides a polyimide with the following structure:

[0081] wherein X is an oxygen atom or a sulfur atom.

[0082] The synthesis method is the same as that of Example 1, and the raw materials 3,3,4,4-tetraminodiphenyl ether and 3,3,4,4-tetraminodiphenyl sulfide are used in a molar ratio of 9:1.

[0083] The obtained polyimide product has a Tg of 280℃ and an ultraviolet absorption cutoff wavelength of 320nm.

[0084] Example 4

[0085] This example provides a polyimide having the following structure:

[0086] wherein X is an oxygen atom or a sulfur atom.

[0087] The synthesis method is the same as that of Example 1, and the diamines are 4,4'-diamino-3,3'-dinitrodiphenyl ether and 4,4'-diamino-3,3'-dinitrodiphenyl sulfide, and the molar ratio of 4,4'-diamino-3,3'-dinitrodiphenyl ether to 4,4'-diamino-3,3'-dinitrodiphenyl sulfide is 8:3.

[0088] The obtained polyimide product has a Tg of 310℃ and an ultraviolet absorption cutoff wavelength of 340nm.

[0089] Comparative Example 1

[0090] The polyamide acid prepared in Example 1 of CN104804434B is used as a comparative compound, and has the following structure:

[0091] Comparative Example 2

[0092] This comparative example provides a polyimide having the following structure:

[0093] The synthesis method is the same as that of Example 1, and the dianhydride is 4,4'-diphenyl ether dianhydride, and the diamine is 4,4'-diaminodiphenyl ether.

[0094] The obtained polyimide product has a Tg of 260℃ and an ultraviolet absorption cutoff wavelength of 240nm.

[0095] Application Examples 1-4 and Comparative Application Examples 1-2

[0096] The polyimides prepared in Examples 1-4 and Comparative Examples 1-2 are respectively used as transfer adhesives for mass transfer, which includes the following steps (the process steps are shown in FIG. 1):

[0097] (1)Sapphire substrate 1 surface (containing light emitting element LD, such as LED) is pasted with transfer release tape (transfer tape 2 + first carrier 3), wherein the transfer tape 2 is the polyimide prepared in the examples or comparative examples of the present application, the first carrier 3 is PET, and the LED is irradiated by laser through the Sapphire substrate;

[0098] (2) After laser irradiation, the LED is separated from the Sapphire substrate, the whole piece is peeled off, and the LED is adhered to the fixed position of the transfer release tape;

[0099] (3) After transfer alignment, laser is irradiated on the transfer release tape through the first carrier 3, which absorbs light energy and sublimates and gasifies, and the LED falls on the designated position of the receiving tape (receiving tape 4 + second carrier 5); wherein the receiving tape 4 is selected from silicone resin, and the second carrier 5 is PET.

[0100] (4) The receiving tape is aligned with the TFT backplane 6, and laser is irradiated on the receiving tape through the second carrier 5, which absorbs light energy and sublimates and gasifies, and the LED falls on the designated position (sub-pixel position) of the backplane, completing mass transfer, and then subsequent processes are performed.

[0101] The transfer yield of the mass transfer in the application examples is evaluated, including transfer accuracy and residual glue rate, by the following method:

[0102] (1) Transfer yield: the percentage of chips that can be lit after transfer is counted per 100,000 LED chips.

[0103] (2) Residual glue rate: the number of chips with residual glue is counted per 100,000 transferred LED chips.

[0104] The evaluation results are shown in Table 1.

[0105] Table 1

[0106] It can be seen that the polyimide resin described in the present application as a transfer tape can make the transfer yield reach more than 99.95%, and the residual glue rate is reduced to less than 0.85%.

[0107] The applicant declares that the polyimide resin and its application of the present application are illustrated by the above examples, but the present application is not limited to the above examples, that is, it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of various raw materials of the product of the present application, addition of auxiliary ingredients, selection of methods, etc. fall within the protection scope and disclosure scope of the present application.

Claims

1. A polyimide resin having the structure shown in Formula I: ###00001### Formula I wherein R1is Y1is an ether or thioether group, Y2is absent or selected from a C1-C5 linear or branched alkyl group, a carbonyl group, a C1-C5 alkyl-carbonyl group, an ether group or a thioether group; R2is selected from X is selected from an ether group, a thioether group, a C1-C10 straight or branched alkyl group, a carbonyl group or a C1-C5 straight or branched alkyl-carbonyl group, R3and R4are independently selected from a nitro group or R7is selected from an alkenyl or alkynyl group; R5and R6are independently selected from hydrogen, halogen, C1-C5 alkyl, C3-C6 cycloalkyl, C1-C5 alkoxy, C6-C12 aryl or C3-C12 heteroaryl; n is selected from an integer from 100 to 500, n1, n2, n3and n4are independently selected from an integer from 0 to 4, and n1and n3are not simultaneously 0, n1+ n3< 4, n2+ n4< 4.

2. The polyimide resin according to claim 1, wherein, said ether group is selected from -O-, wherein m and p are independently integers from 1 to 5.

3. The polyimide resin according to claim 1, wherein, said thioether group is selected from -S-, wherein m1 and p1 are independently integers from 1-5.

4. The polyimide resin according to claim 1, wherein, R1is wherein Y3is selected from O or S, Y4is selected from a C1-C5 linear or branched alkyl group, a carbonyl group, a C1-C5 alkyl-carbonyl group, an ether group or a thioether group, and m2is selected from an integer from 1 to 5.

5. The polyimide resin according to claim 4, wherein, Y4is selected from -0-, -S-, carbonyl, -CH2- or 6. The polyimide resin according to claim 1 or 4, wherein, R1is 7. The polyimide resin according to claim 1, wherein, X is selected from the group consisting of -CH2-, -O-, -S-, m, p, m1 and p1 are independently an integer from 1 to 5.

8. The polyimide resin according to claim 1, wherein, said alkenyl group is selected from a C2-C8 alkenyl group.

9. The polyimide resin according to claim 1, wherein, said alkynyl group is selected from a C2-C8 alkynyl group.

10. The polyimide resin according to claim 1, wherein, said R7is selected from the wavy line represents the point of attachment of the group.

11. The polyimide resin according to claim 1, wherein, R3and R4are independently selected from the group consisting of nitro, 12. The polyimide resin according to claim 1 or 11, wherein, R3and R4are selected from the same group.

13. The polyimide resin according to claim 1, wherein, R5and R6are independently selected from hydrogen, F, Cl, Br, methyl, ethyl, isopropyl, pentyl, cyclopropyl, cyclohexyl, methoxy, ethoxy, phenyl, biphenyl, naphthyl, pyridyl, furanyl, triazinyl, benzofuranyl or dibenzofuranyl.

14. The polyimide resin according to claim 1, wherein, R2is selected from R3, R4, X, n1and n2are as defined in claim 1.

15. The polyimide resin according to claim 1, wherein, R2is selected from R3, R4, X are as defined in claim 1.

16. The polyimide resin according to claim 15, wherein, R2is selected from X is as defined in claim 1.

17. The polyimide resin of claim 1 having any one of the following structures of Formulae II-VI: wherein n and X are as defined in claim 1.

18. The polyimide resin according to claim 1, which is any one of the following compounds: wherein n is selected from an integer from 100 to 500.

19. A transfer adhesive comprising the polyimide resin according to any one of claims 1-18.

20. A receiving adhesive comprising the polyimide resin according to any one of claims 1-18.

21. Use of the polyimide resin according to any one of claims 1-18 or the transfer adhesive according to claim 19 or the receiving adhesive according to claim 20 in mass transfer.

22. A method of mass transfer comprising using the polyimide resin according to any one of claims 1-18 as a transfer adhesive.

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