Liquid mold sealant for printing, chip and preparation method therefor

Abstract

A liquid mold sealant for printing, a chip and a preparation method therefor. The liquid mold sealant for printing comprises the following components in parts by weight: 10-20 parts of an epoxy resin, 100-200 parts of silicon dioxide, 15-25 parts of a curing agent, 1-5 parts of a reactive diluent, 0.1-0.5 parts of a latent curing agent, 0.1-1 part of a coupling agent and 0.1-0.5 parts of a coloring agent, wherein the epoxy resin comprises N-(2-methylphenyl)-N-(1,2-epoxypropyl)-oxirane methylamine. By means of a mutual synergistic effect of the components in the liquid mold sealant for printing, the mold sealant for printing can not only complete the two steps of bottom filling and external mold sealing of a chip in one step, but can also reduce a warping degree after curing and improve the manufacturing yield of the chip.

Description

Liquid mold sealant for printing, chip and preparation method thereof Technical Field

[0001] The present invention belongs to the technical field of semiconductor chip packaging, and in particular relates to a liquid mold sealant for printing, a chip and a preparation method thereof. Background Art

[0002] In recent years, chip packaging technology has been trending toward higher speeds, larger sizes, higher pin counts, and higher power. Underfill is an essential material for chip packaging. It fills the gap between the chip and the substrate and solidifies to form the underfill material, protecting the chip, substrate, and solder joints, making components more widely applicable and reliable.

[0003] During chip fabrication, in addition to filling the bottom of the chip, an encapsulation layer must be placed around the chip and the underfill layer. However, the underfill and encapsulation layers have different functions and require different compositions. Currently, two different compositions are typically used for the filling and encapsulation layers. After the filling and encapsulation layers are fabricated, an identification layer is applied to the surface, complicating the chip fabrication process. Furthermore, consideration must be given to the connection between the various layers and the warpage after curing.

[0004] Therefore, how to provide a printed liquid molding adhesive, a chip and a preparation method thereof to complete the two steps of bottom filling and external molding of the chip in one step while reducing the warping after curing is a technical problem that technical personnel in this field urgently need to solve.

[0005] Summary of the Invention

[0006] The object of the present invention is to provide a liquid mold sealant for printing, a chip and a preparation method thereof, so as to solve at least one of the above-mentioned technical problems.

[0007] To achieve the above objectives, the first aspect of the present invention provides a liquid mold sealant for printing, which comprises the following components, by weight: 10-20 parts of epoxy resin, 100-200 parts of silicon dioxide, 15-25 parts of curing agent, 1-5 parts of reactive diluent, 0.1-0.5 parts of latent curing agent, 0.1-1 parts of coupling agent and 0.1-0.5 parts of colorant; wherein the epoxy resin comprises N-(2-methylphenyl)-N-(1,2-epoxypropyl)-oxiranylmethylamine.

[0008] In the first aspect, the latent curing agent includes at least one of 2-ethyl-4-methylimidazole and a microcapsule-modified imidazole epoxy composition.

[0009] In the first aspect, the curing agent comprises nadic methyl anhydride.

[0010] In the first aspect, the reactive diluent includes a DCPDM epoxy resin, and the structural formula of the DCPDM epoxy resin is:

[0011] In the first aspect, the coupling agent includes γ-glycidoxypropyltrimethoxysilane.

[0012] In the first aspect, the colorant includes carbon black.

[0013] The second aspect of the present invention provides a method for preparing a liquid mold sealant for printing as described in the first aspect, the preparation method comprising: stirring and mixing the components to obtain a preliminary mixed slurry, wherein the components include at least 10-20 parts of epoxy resin, 100-200 parts of silica, 15-25 parts of curing agent, 1-5 parts of reactive diluent, 0.1-0.5 parts of latent curing agent, 0.1-1 parts of coupling agent and 0.1-0.5 parts of colorant; transferring the preliminary mixed slurry to a three-roll grinder for grinding to obtain a ground slurry; and vacuum degassing the ground slurry to obtain a liquid mold sealant for printing.

[0014] A third aspect of the present invention provides a method for preparing a chip, the method comprising: obtaining a chip body; providing templates at both ends of the chip body, the templates being higher than the chip body; placing a printing liquid mold sealant as described in the first aspect on the template at one end; at room temperature, using a rubber scraper to flatten the printing liquid mold sealant within the templates at both ends; curing; after curing, removing the templates at both ends to obtain a chip.

[0015] In the third aspect, the marking is performed directly on the surface of the chip.

[0016] A fourth aspect of the present invention provides a chip, comprising a chip body and a molding layer; the molding layer comprises a printing liquid molding compound as described in the first aspect, and the molding layer wraps the chip body. Beneficial effects:

[0017] The liquid mold sealant for printing provided by the present invention comprises the following components in parts by weight: 10-20 parts of epoxy resin, 100-200 parts of silicon dioxide, 15-25 parts of curing agent, 1-5 parts of reactive diluent, 0.1-0.5 parts of latent curing agent, 0.1-1 parts of coupling agent and 0.1-0.5 parts of colorant; wherein the epoxy resin comprises N-(2-methylphenyl)-N-(1,2-epoxypropyl)-oxiranylmethylamine; the reactive diluent is used to improve the wettability of the liquid mold sealant for printing, so that the liquid mold sealant for printing is leveled during printing, so as to perform bottom filling and external mold sealing on the chip; at the same time, the low-viscosity N-(2-methylphenyl)-N-(1,2-epoxypropyl)-oxiranylmethylamine is used. )-N-(1,2-epoxypropyl)-oxiranylmethylamine is used as the epoxy resin matrix and silica is used as the filler to form an island structure between the two, and a coupling agent is used to promote the compatibility between the epoxy resin matrix and the filler to achieve toughening of the printed liquid mold sealant, thereby reducing the warpage of the printed liquid mold sealant after curing; a latent curing agent is added to improve the quality of the printed liquid mold sealant, thereby improving the chip production efficiency; this application uses the mutual synergistic effect between the various components in the printed liquid mold sealant to enable the printed mold sealant to not only complete the two steps of bottom filling and external molding of the chip in one step, but also reduce the warpage after curing and improve the chip production yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] FIG1 is a schematic diagram of a chip preparation method provided in an embodiment of the present application.

[0020] Reference numerals: 1. template; 2. liquid mold sealant for printing; 3. rubber scraper; 4. chip body. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below in conjunction with specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly presented. It should be understood by those skilled in the art that these specific embodiments and examples are for illustrating the present invention, rather than for limiting the present invention.

[0022] Throughout this specification, unless otherwise specified, the terms used herein should be understood as having the same meaning as commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In the event of any conflict, the present specification shall take precedence.

[0023] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or obtained through existing methods.

[0024] The present application provides a liquid mold sealant for printing, which includes the following components in parts by weight: 10-20 parts of epoxy resin, 100-200 parts of silicon dioxide, 15-25 parts of curing agent, 1-5 parts of reactive diluent, 0.1-0.5 parts of latent curing agent, 0.1-1 parts of coupling agent and 0.1-0.5 parts of colorant; wherein the epoxy resin includes N-(2-methylphenyl)-N-(1,2-epoxypropyl)-oxiranylmethylamine.

[0025] Specifically, the liquid mold sealant for printing provided by the present invention comprises the following components in parts by weight: 10-20 parts of epoxy resin, 100-200 parts of silicon dioxide, 15-25 parts of curing agent, 1-5 parts of reactive diluent, 0.1-0.5 parts of latent curing agent, 0.1-1 parts of coupling agent and 0.1-0.5 parts of colorant; wherein, the epoxy resin comprises N-(2-methylphenyl)-N-(1,2-epoxypropyl)-oxiranylmethylamine; the reactive diluent is used to improve the wettability of the liquid mold sealant for printing, so that the liquid mold sealant for printing is leveled during printing, so as to perform bottom filling and external mold sealing on the chip; at the same time, the low viscosity N-(2-methylphenyl)-N-(1,2-epoxypropyl)-oxiranylmethylamine is used. The invention relates to a method for preparing a printed liquid mold sealant by using N-(2-methylphenyl)-N-(1,2-epoxypropyl)-oxiranylmethylamine as an epoxy resin matrix and silica as a filler, so that an island structure is formed between the two, and a coupling agent is used to promote the compatibility between the epoxy resin matrix and the filler, thereby achieving toughening of the printed liquid mold sealant, thereby reducing the warpage of the printed liquid mold sealant after curing; adding a latent curing agent to improve the quality of the printed liquid mold sealant, thereby improving the chip production efficiency; the present application uses the mutual synergistic effect between the various components in the printed liquid mold sealant, so that the printed mold sealant can not only complete the bottom filling and external molding of the chip in one step, but also reduce the warpage after curing, thereby improving the chip production yield. N-(2-methylphenyl)-N-(1,2-epoxypropyl)-oxiranylmethylamine can be obtained by preparation or purchased on the market, for example, it can be the EP-3980S product of ADEKA Corporation.

[0026] In some possible embodiments, the latent curing agent includes at least one of 2-ethyl-4-methylimidazole and a microcapsule-modified imidazole epoxy composition.

[0027] When added to an epoxy resin at room temperature, the latent curing agent exhibits a certain degree of storage stability. However, its reactivity can be released under external conditions such as heating, light, moisture, and pressure, thereby allowing the epoxy resin to cure rapidly. In this embodiment, the latent curing agent is an imidazole curing agent. Preferably, the latent curing agent comprises at least one of 2-ethyl-4-methylimidazole and a microcapsule-modified imidazole epoxy composition. The microcapsule-modified imidazole epoxy composition can be prepared or purchased commercially, for example, SC10208E from Shanghai Sok Purification Materials Co., Ltd.

[0028] In some possible embodiments, the curing agent includes methyl nadic anhydride, which is used to cure the epoxy resin. Methyl nadic anhydride can be prepared or purchased from the market, for example, a product of Nippon Kayaku Co., Ltd.

[0029] In some possible embodiments, the reactive diluent includes a DCPDM epoxy resin, and the structural formula of the DCPDM epoxy resin is:

[0030] DCPDM epoxy resin is used as a reactive diluent for epoxy resins, improving wettability and facilitating adhesive leveling during printing. It provides excellent dilution, prevents bubbles and liquid seepage, and produces a smooth surface finish. It also has no impact on the basic properties of cured epoxy resins, such as shrinkage, heat distortion temperature, impact strength, and tensile strength. DCPDM epoxy resins can be prepared or purchased commercially, for example, EP-4088L from ADEKA Corporation.

[0031] In some possible embodiments, the coupling agent includes γ-glycidyloxypropyltrimethoxysilane, which is used to promote the compatibility of silica with the epoxy resin matrix.

[0032] In some possible embodiments, the colorant includes carbon black for dyeing.

[0033] Based on a general inventive concept, the present application also provides a method for preparing a liquid mold sealant for printing, the preparation method comprising: stirring and mixing the components to obtain a preliminary mixed slurry, wherein the components include at least, by weight: 10-20 parts of epoxy resin, 100-200 parts of silica, 15-25 parts of curing agent, 1-5 parts of reactive diluent, 0.1-0.5 parts of latent curing agent, 0.1-1 parts of coupling agent and 0.1-0.5 parts of colorant; transferring the preliminary mixed slurry to a three-roll grinder for grinding to obtain a ground slurry; and vacuum degassing the ground slurry to obtain a liquid mold sealant for printing.

[0034] Based on a general inventive concept, the present application also provides a method for preparing a chip, which comprises: obtaining a chip body; providing templates at both ends of the chip body, the templates being higher than the chip body; placing a printing liquid mold sealant as described in the above embodiment on the template at one end; at room temperature, using a rubber scraper to flatten the printing liquid mold sealant inside the templates at both ends; curing; after curing, removing the templates at both ends to obtain a chip.

[0035] The printed liquid mold sealant provided in this application combines the functions of sealing and protecting chips. Using a template printing process, the printed liquid mold sealant provided in this application can complete both the chip bottom filling and external mold sealing steps in a single step, reducing costs. The printed liquid mold sealant also provides a smooth surface after curing.

[0036] In some possible embodiments, the preparation method further includes: directly marking the surface of the chip.

[0037] Since the marking can be made directly on the surface of the chip, the step of making the marking after applying the back protective film is reduced, the chip production time is shortened, and the chip production efficiency is improved.

[0038] Based on a general inventive concept, the present invention provides a chip, which includes a chip body and a molding layer; the molding layer is composed of a printing liquid molding adhesive as described in the above embodiment, and the molding layer wraps the chip body.

[0039] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present application only and are not intended to limit the scope of the present application. The experimental methods in the following examples where specific conditions are not specified are usually measured in accordance with national standards. If there are no corresponding national standards, then the methods are carried out in accordance with general international standards, conventional conditions, or according to the conditions recommended by the manufacturer.

[0040] Examples 1-3 and Comparative Examples 1-2 are liquid mold sealants for printing. The components of the liquid mold sealants for printing are shown in the following table in parts by weight:

[0041] The viscosity (rotational viscosity) and warpage of the printing liquid mold sealant provided in Examples 1-3 and Comparative Examples 1-2 were tested. The specific test process is as follows:

[0042] 1. Rotational viscosity test method: Keep the sample at a constant temperature of 25°C, use a Brookfield viscometer, place the glue in the 6R sleeve of the viscometer, select the SC4-14 rotor, adjust the viscometer speed to 20 rpm, and read the viscosity value after 4 minutes;

[0043] The successfully prepared glue solution was allowed to stand for 24 hours, and the 24-hour rotational viscosity was measured according to the above-mentioned rotational viscosity test method.

[0044] 2. Warpage test method: Apply the glue evenly on a glass slide, bake at 150°C for 1 hour, and remove it after natural cooling. Remove the residual resin around the slide, fix one side of the slide, and use a ruler to measure the distance the slide is lifted. This distance is recorded as the warpage.

[0045] The test results are shown in the following table:

[0046] As can be seen from the above table, the liquid mold sealant for printing prepared using the component proportions provided in Examples 1-3 of the present invention has a low rotational viscosity, and still has a low rotational viscosity after standing for 24 hours, indicating that the liquid mold sealant for printing provided by this application has a long service life and can ensure that the liquid mold sealant for printing has a low warpage after curing.

[0047] Comparing Example 1 with Control Example 1, it can be seen that compared with bisphenol F epoxy resin, EP-3980S has lower viscosity and excellent adhesion, which is conducive to the implementation of the template printing process, and has lower warpage after curing.

[0048] By comparing Example 2 and Control Example 2, it can be seen that, under the same conditions, the glue prepared by using imidazole latent curing agent as the accelerator for epoxy resin has lower viscosity and lower warpage than the glue prepared by using amine curing agent as the accelerator for epoxy resin, and after 24 hours, the rotational viscosity does not change much, indicating that it has a longer service life and the prepared glue has a certain stability.

[0049] Finally, it should be noted that the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0050] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0051] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A liquid mold sealant for printing, characterized in that: The liquid mold sealant for printing is composed of the following components by weight: 10-20 parts of epoxy resin, 100-200 parts of silicon dioxide, 15-25 parts of curing agent, 1-5 parts of active diluent, 0.1-0.5 parts of latent curing agent, 0.1-1 parts of coupling agent and 0.1-0.5 parts of colorant; wherein the epoxy resin is N-(2-methylphenyl)-N-(1,2-epoxypropyl)-oxiranylmethylamine; the latent curing agent includes at least one of 2-ethyl-4-methylimidazole and microcapsule modified imidazole epoxy composition; the curing agent includes methyl nadic anhydride; the coupling agent includes γ-glycidyloxypropyltrimethoxysilane; The active diluent includes a DCPDM epoxy resin, and the structural formula of the DCPDM epoxy resin is:

2. The liquid mold sealant for printing according to claim 1, characterized in that: The colorant includes carbon black.

3. A method for preparing a liquid mold sealant for printing as claimed in any one of claims 1 to 2, characterized in that: The preparation method comprises: The components are stirred and mixed to obtain a preliminary mixed slurry, wherein the components include at least 10-20 parts of epoxy resin, 100-200 parts of silicon dioxide, 15-25 parts of curing agent, 1-5 parts of reactive diluent, 0.1-0.5 parts of latent curing agent, 0.1-1 parts of coupling agent and 0.1-0.5 parts of colorant by weight; Transferring the preliminary mixed slurry to a three-roll mill for grinding to obtain a ground slurry; The grinding slurry is vacuum degassed to obtain a liquid mold sealant for printing.

4. A method for preparing a chip, characterized in that: The preparation method comprises: Get the chip body; Templates are provided at both ends of the chip body, and the templates are higher than the chip body; A printing liquid mold sealant as claimed in any one of claims 1 to 2 is placed on the template at one end; At room temperature, use a rubber scraper to scrape the liquid mold sealant for printing flat inside the templates at both ends; To cure; After curing, the templates at both ends are removed to obtain a chip.

5. The method for preparing a chip according to claim 4, characterized in that: The preparation method further comprises: The marking is performed directly on the surface of the chip.

6. A chip, characterized in that: The chip comprises a chip body and a molding layer; the molding layer comprises a printing liquid molding adhesive as described in any one of claims 1 to 2, and the molding layer wraps the chip body.

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