Non-conductive high-thermal-conductivity copper oxide sizing material and preparation method thereof

Abstract

The invention provides a non-conductive high-thermal-conductivity copper oxide sizing material and a preparation method thereof. The copper oxide sizing material comprises 10 to 19 weight percent of water-based resin and 81 to 90 weight percent of copper oxide spherical nano powder with solid content. The water-based resin comprises epoxy resin, a silane coupling agent and polyethylene glycol, and the copper oxide spherical nanometer powder is prepared by spray drying and granulation. The preparation method comprises the following steps: mixing copper oxide nano powder with a surfactant to prepare a copper oxide aqueous solution; carrying out spray drying granulation on the copper oxide aqueous solution to obtain copper oxide spherical nano powder; mixing water-based resin with the copper oxide spherical nanometer powder to obtain a mixed sizing material; and carrying out three-roller grinding, and dispersing the mixed sizing material to obtain the non-conductive and high-thermal-conductivity copper oxide sizing material. The thermal conductivity of the non-conductive and high-thermal-conductivity copper oxide adhesive disclosed by the invention is between 2.145 W / mK and 3.11 W / mK.

Description

Technical Field

[0001] The invention relates to a non-conductive and high thermal conductive adhesive and a preparation method thereof, in particular to a non-conductive and high thermal conductive copper oxide adhesive used for semiconductor packaging and a preparation method thereof. Background Art

[0002] Semiconductor packaging is the process of coating the cut dies with packaging materials after sawing, pick-up, die bonding, and wire bonding of the wafers that have been processed in the semiconductor front end, in order to protect the durability and service life of the completed integrated circuit (IC) components (such as chips), and facilitate the wide application of circuit board assembly. Die attach film (DAF) can be used to bond the wiring substrate to the semiconductor die, or between semiconductor dies. It can effectively prevent the scattered arrangement of the dies caused by cutting during laser cutting.

[0003] With the popularization of the 5G era, terminal electronic products are increasingly demanding lightweight, thin and short applications, and their related packaging technologies are gradually developing towards miniaturization, high density and thinness. As the current density increases, the heat dissipation and insulation requirements increase accordingly, and the thermal conductivity requirements for packaging materials are also gradually increasing.

[0004] Die Attach Adhesive is used in metal-oxide-semiconductor field-effect transistors (MOSFET), heat sinks, ball grid array packages (BGA), quad flat no-lead packages (QFN), plastic ball gate array package substrates (PBGA), plastic quad flat packages (QFP), LQPD, LPDDP, etc. According to the needs of different application levels, the adhesive materials of chip adhesives have various conductive, thermal and insulating properties.

[0005] The existing non-conductive packaging materials are mainly filled with micron-sized SiO2 or Al2O3 powder. The thermal conductivity of Al2O3 powder is 17.65W / mK, but due to its large size, it is difficult to increase the solid content, and the powder has poor contact, making it difficult to improve the thermal conductivity of the adhesive. The thermal conductivity of the adhesive film is about 0.766W / mK, and the solid content is about 70wt.% to 80wt.%. In addition, the existing technology also uses general copper oxide nanopowder as a thermal conductive adhesive filler. However, due to the influence of van der Waals force, copper oxide nanopowder is more difficult to disperse, so that the solid content is difficult to increase.

[0006] Accordingly, providing a non-conductive and highly thermally conductive copper oxide paste and a preparation method thereof to solve the technical problem that the prior art is difficult to improve powder contact and increase solid content is an important topic that this application is committed to studying. Summary of the invention

[0007] The main purpose of the present invention is to provide a non-conductive and highly thermally conductive copper oxide glue which can be used as a die attach adhesive in semiconductor processes. The total weight of the copper oxide glue is 100wt.%, and the copper oxide glue comprises: 10wt.% to 19wt.% of an aqueous resin, which comprises an epoxy resin, a silane coupling agent and polyethylene glycol; and 81wt.% to 90wt.% of copper oxide spherical nanopowder with a solid content, and the copper oxide spherical nanopowder is made by spray drying and granulation; wherein the thermal conductivity of the non-conductive and highly thermally conductive copper oxide glue is between 2.145W / mK and 3.11W / mK.

[0008] In a specific embodiment of the present invention, the epoxy resin is selected from at least one of bisphenol A epoxy resin, bisphenol F epoxy resin and cyanuric acid epoxy resin or a combination of more.

[0009] In a specific embodiment of the present invention, the silane coupling agent is selected from at least one of methacryloxy silane, epoxy silane, and isocyanate silane, or a combination of more than one of them.

[0010] In a specific embodiment of the present invention, taking the total weight of the water-based resin as 100 wt.%, the weight percentages of the epoxy resin: the silane coupling agent: the polyethylene glycol are between 90-95 wt.%, 1-5 wt.%, and 1-9 wt.%.

[0011] In order to achieve the above-mentioned purpose, the present invention also provides a method for preparing a non-conductive and high thermal conductive copper oxide glue, which comprises: preparing a copper oxide aqueous solution with a ratio of 30wt.%:70wt.% of copper oxide nanopowder and a surfactant; granulating the copper oxide aqueous solution by spray drying to obtain a copper oxide spherical nanopowder; mixing an aqueous resin with the copper oxide spherical nanopowder to obtain a mixed glue; and grinding and dispersing the mixed glue by three rollers to obtain a non-conductive and high thermal conductive copper oxide glue; wherein, based on the total weight of the copper oxide glue being 100wt.%, the copper oxide glue comprises: 10wt.% to 19wt.% of an aqueous resin, which comprises an epoxy resin, a silane coupling agent and polyethylene glycol, and 81wt.% to 90wt.% of the copper oxide spherical nanopowder; wherein the thermal conductivity of the non-conductive and high thermal conductive copper oxide glue is between 2.145W / mK and 3.11W / mK. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1A This is a SEM image of copper oxide nanopowder that is not spray-dried and granulated in the prior art;

[0013] Figure 1B is a SEM image of the copper oxide nanopowder granulated by spray drying of the present invention;

[0014] Figure 1C for Figure 1B SEM partial magnified image; and

[0015] Figure 2 The present invention is a flow chart of a method for preparing a non-conductive and highly thermally conductive copper oxide adhesive.

[0016] Wherein, the reference numerals are:

[0017] S100~S400: steps. DETAILED DESCRIPTION

[0018] The non-conductive and highly thermally conductive bonding film and its preparation method disclosed in the present invention are described in detail with reference to the specific embodiments of the present invention in conjunction with the drawings. A person skilled in the art can understand the advantages and effects of the present invention through the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the concept of the present invention. The following embodiments will further describe the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0019] The main purpose of the present invention is to provide a non-conductive and highly thermally conductive copper oxide glue, wherein the total weight of the copper oxide glue is 100wt.%, the copper oxide glue comprises: 10wt.% to 19wt.% of an aqueous resin, which comprises an epoxy resin, a silane coupling agent and polyethylene glycol; and 81wt.% to 90wt.% of copper oxide spherical nanopowder with a solid content, and the copper oxide spherical nanopowder is made by spray drying and granulation; wherein the thermal conductivity of the non-conductive and highly thermally conductive copper oxide glue is between 2.145W / mK and 3.11W / mK.

[0020] Copper oxide nanopowder has insulating properties and can be used as a filler for thermal conductive adhesives. However, due to the influence of van der Waals forces, copper oxide nanopowder is generally difficult to disperse, so that the solid content is difficult to increase to more than 75%, and the thermal conductivity of thermal conductive adhesives prepared with copper oxide nanopowder is generally only 0.896W / mK.

[0021] The copper oxide nanopowder of the present invention presents spherical nanopowder after spray drying and granulation, has better fluidity, and can increase the solid content in the thermal conductive adhesive. Compared with other processes, for example, adjusting the mixing method (such as high gravity process), adding solvents (such as alcohols), using surfactants (such as PVP) or surface modifiers, and heating methods (such as microwaves), the spray drying granulation process of the present invention is simpler. In other words, the copper oxide nanopowder of the present invention presents spherical nanopowder after the spray drying and granulation process, and no additional surface modifier treatment is required.

[0022] See also Figure 1A , Figure 1B as well as Figure 1C , which is the surface morphology analysis of copper oxide nanopowder, Figure 1A SEM images showing general copper oxide nanopowders. Figure 1B The SEM image of copper oxide nanopowder after spray drying and granulation is shown. Figure 1C for Figure 1B The SEM partial magnified image shows that after spray drying and granulation, the copper oxide nanopowder is spherical and has better fluidity, which can greatly increase the copper oxide solid content in the thermal conductive adhesive to more than 75wt.%. More preferably, the copper oxide solid content in the thermal conductive adhesive can be increased to more than 80wt.%, and the contact area of ​​the copper oxide powder can be increased. The thermal conductivity of the prepared thermal conductive adhesive can reach more than 2.145W / mK.

[0023] Furthermore, the composition formula of the copper oxide glue of the present invention is described in detail as follows.

[0024] Epoxy resin has excellent electrical properties, low curing shrinkage, low volatile byproducts, high temperature resistance, solvent resistance and other characteristics, and is widely used in semiconductor component packaging materials. After hardening, epoxy resin forms a dense and brittle cross-linked protective layer. If the stress accumulated inside is not properly controlled, it is easy to increase the failure rate of subsequent integrated circuit component preparation.

[0025] In a specific embodiment of the present invention, the epoxy resin selected by the present invention is selected from at least one or a combination of bisphenol A epoxy resin, bisphenol F epoxy resin and cyanuric acid epoxy resin. Bisphenol A epoxy resin is a commonly used epoxy resin, which has excellent curing properties such as heat resistance, insulation, adhesion, etc., and also has a high degree of freedom in resin design. Therefore, it is widely used in the industrial field. Preferably, the epoxy resin described in the present invention is bisphenol F epoxy resin. Specifically, bisphenol F epoxy resin is also called bisphenol F diglycidyl ether, referred to as BPF, which has the characteristics of low viscosity, corrosion resistance, adhesion, thermal stability and insulation.

[0026] In order to specifically compare the thermal conductivity differences of the epoxy resins used in the present invention, copper oxide spherical nanopowders with a solid content of 87% were mixed with 13wt.% of an aqueous resin to prepare thermal conductive adhesive material Examples 1 to 3. In the composition of the aqueous resin, epoxy silane coupling agents and PEG-200 polyethylene glycol were selected, and thermal conductivity tests were performed. The composition ratio of the aqueous resin is shown in Table 1.

[0027] Table 1

[0028]

[0029]

[0030] As shown in Table 1, bisphenol A epoxy resin, bisphenol F epoxy resin and cyanuric acid epoxy resin all show excellent thermal conductivity under the same ratio, and the thermal conductive adhesive made with bisphenol F epoxy resin can show the best thermal conductivity.

[0031] Silane coupling agent is a compound composed of organic matter and silicon. The silane coupling agent has two or more different reactive groups in its molecules, and can react chemically with inorganic materials and organic materials. Specifically, the silane coupling agent of the present invention can improve the connectivity between copper oxide and epoxy resin, avoid defects such as holes at the interface, and maintain better thermal conductivity.

[0032] In a specific embodiment of the present invention, the silane coupling agent is selected from at least one of methacryloxysilane, epoxysilane, and isocyanate silane, or a combination of more. More specifically, the silane coupling agent of the present invention can be a commercially available product. For example, methacryloxysilane can be a combination of 3-methacryloxypropyl and other silanes, such as methyldimethoxysilane, trimethoxysilane, methyldiethoxysilane, and triethoxysilane; epoxysilane can be 2-(3,4-epoxycyclohexylethyltrimethoxysilane, (3-glycidoxypropyl)trimethoxysilane, (3-glycidoxypropyl)methyldiethoxysilane, and (3-glycidoxypropyltriethoxysilane; isocyanate silane can be 3-isocyanatepropyltriethoxysilane.

[0033] In order to specifically compare the difference in thermal conductivity of the thermally conductive adhesives prepared by the silane coupling agents selected in the present invention, copper oxide spherical nanopowder with a solid content of 87% was mixed with 13wt.% of an aqueous resin to prepare thermally conductive adhesive examples 4 to 6. The composition of the aqueous resin selected bisphenol F epoxy resin, epoxy silane coupling agent and PEG-200 polyethylene glycol, and thermal conductivity tests were performed. The composition and ratio of the aqueous resin are shown in Table 2.

[0034] Table 2

[0035]

[0036]

[0037] Among them, the thermal conductive adhesives prepared with methacryloxysilane, epoxysilane, and isocyanatesilane all showed a thermal conductivity greater than 2.145W / mK, and the thermal conductive adhesive made with epoxysilane showed the best thermal conductivity. More specifically, the thermal conductive adhesive made with (3-glycidoxypropyl)trimethoxysilane showed the best thermal conductivity.

[0038] Polyethylene glycol (PEG) is a polymer of ethylene oxide, has a wide range of chemical compatibility, and is commonly used in the fields of industry, medicine, cosmetics, etc. Preferably, the polyethylene glycol of the present invention can be selected from PEG-200, PEG-400, PEG-600, and more preferably, polyethylene glycol PEG-200 with an average molecular weight of 200 can be selected.

[0039] The water-based resin used in the present invention includes epoxy resin, silane coupling agent and polyethylene glycol. In a specific embodiment of the present invention, the water-based resin has a specific ratio, with the total weight of the water-based resin being 100wt.%, and the weight percentage of epoxy resin: silane coupling agent: polyethylene glycol is between 90-95wt.%: 1-5wt.%: 1-9wt.%. In order to specifically compare the difference in the proportional thermal conductivity of the water-based resin formula of the present invention, copper oxide spherical nanopowder with a solid content of 87% and 13wt.% water-based resin are mixed to prepare thermal conductive adhesive material embodiments 7 to 15. The composition of the water-based resin is selected from bisphenol F epoxy resin, epoxy silane coupling agent and PEG-200 polyethylene glycol, and the thermal conductivity test is carried out. The composition ratio of the water-based resin is shown in Table 3.

[0040] Table 3

[0041]

[0042]

[0043] The copper oxide glue material includes 80wt.% to 90wt.% solid content of copper oxide spherical nanopowder and 10wt.% to 20wt.% water-based resin. In order to specifically compare the difference in thermal conductivity of the copper oxide spherical nanopowder and the water-based resin of the present invention, the copper oxide spherical nanopowder with a solid content of 80wt.% to 90wt.% and 10wt.% to 20wt.% water-based resin (based on the component ratio of Example 12) are mixed to prepare thermal conductive glue Examples 16 to 18 and Comparative Example 1, and thermal conductivity tests are performed, and the ratios are shown in Table 4.

[0044] Table 4

[0045]

[0046] As can be seen from Table 4, the copper oxide sizing agent of the present invention can effectively increase the solid content of the copper oxide spherical nanopowder to more than 80wt.%, preferably, the solid content of the copper oxide spherical nanopowder is between 81wt.% and 90wt.%. More preferably, the solid content of the copper oxide spherical nanopowder is between 81wt.% and 89wt.%, and more preferably, between 81wt.% and 87wt.%. When the solid content is greater than 90wt.%, the viscosity of the sizing agent is too high, so that the product is difficult to operate.

[0047] [Test example]

[0048] The copper oxide adhesive provided by the present invention not only provides high thermal conductivity, but also has excellent insulation properties. In order to confirm the non-conductive insulation properties, the adhesive film prepared by the copper oxide adhesive, the adhesive film prepared by general copper oxide powder (not spray-dried and granulated), and the non-commercial aluminum oxide adhesive film were further measured using an AC withstand voltage tester, and the results are recorded in Table 5.

[0049] Table 5

[0050]

[0051]

[0052] * Alumina Al2O3 adhesive film was purchased from Henkel (Model ATB F125E)

[0053] As can be seen from Table 5, the adhesive film prepared by spray-dried granulated copper oxide of the present invention has the same insulating effect as the aluminum oxide Al2O3 adhesive film commercially available in the prior art or the adhesive film prepared by non-spray-dried granulated copper oxide. The spray-dried granulated copper oxide of the present invention can prepare a thinner film thickness than the aluminum oxide Al2O3 adhesive film, and has excellent thermal conductivity. Compared with the adhesive film prepared by non-spray-dried granulated copper oxide, the spray-dried granulated copper oxide spherical nanopowder of the present invention has better fluidity, increased contact area, and increased solid content in the overall composition to 80wt.% to 87wt.%, and has higher thermal conductivity than the general non-spray-dried granulated copper oxide nanopowder (solid content 70wt.% to 75wt.%).

[0054] In order to achieve the above-mentioned object, the present invention also provides a method for preparing a non-conductive and high thermal conductive copper oxide glue. Figure 2 , which are steps S100 to S400 of the method for preparing the non-conductive and highly thermally conductive copper oxide glue of the present invention.

[0055] S100: copper monoxide nanopowder and surfactant are prepared into a copper monoxide aqueous solution at a ratio of 30wt.%:70wt.%. More specifically, the surfactant can be polyoxyethylene (40) nonylphenyl ether (Polyoxyethylene (40) nonylphenyl ether) prepared into a 3wt% aqueous solution, and polyoxyethylene (40) nonylphenyl ether can be a commercially available product, such as CO-890.

[0056] S200: The copper oxide aqueous solution is granulated by spray drying to obtain copper oxide spherical nanopowder. The spray dryer uses an exhaust fan and a blower to send heated and purified air into the machine body, and another set of high-speed rotating spray heads atomizes the copper oxide aqueous solution sent by the pump into extremely small water droplets, which combine with the hot air to instantly evaporate the water in the liquid and take it away, while the solid components are obtained through the collector to achieve the purpose of direct drying.

[0057] S300: Mix a water-based resin and the copper oxide spherical nanopowder to obtain a mixed rubber material. The total weight of the mixed rubber material is 100wt.%, which includes 10wt.% to 19wt.% of the water-based resin and 81wt.% to 90wt.% of the copper oxide spherical nanopowder with a solid content. The total weight of the water-based resin is 100wt.%, and the formula is 90-95wt.%: 1-5wt.%: 1-9wt.% of epoxy resin: silane coupling agent: polyethylene glycol. The selection of these components is as described in the specification of the present invention, and will not be repeated here.

[0058] S400: The mixed rubber material is uniformly mixed with a triple roll mill to obtain a non-conductive and high thermal conductive copper oxide rubber material. The triple roll mill is a machine that uses three parallel rollers to rotate in opposite directions and at different speeds to generate shear force, thereby achieving the purpose of mixing, refining, dispersing, or making the viscosity of an object uniform.

[0059] One of the beneficial effects of the present invention is that the non-conductive and highly thermally conductive copper oxide glue provided by the present invention improves the fluidity of the copper oxide spherical nanopowder, increases the contact area, and increases the solid content of the copper oxide spherical nanopowder in the composition by "the copper oxide spherical nanopowder is made by spray drying and granulation". The non-conductive and highly thermally conductive copper oxide glue of the present invention includes the specific composition and formula ratio of "10wt.% to 19wt.% of water-based resin, which includes epoxy resin, silane coupling agent and polyethylene glycol; and 81wt.% to 90wt.% of solid content of copper oxide spherical nanopowder", which effectively improves the thermal conductivity of the non-conductive and highly thermally conductive copper oxide glue prepared by the present invention to between 2.145 and 3.11W / mK.

[0060] In addition, the "preparation method of non-conductive and highly thermally conductive copper oxide sizing material" provided by the present invention is simpler than other processes, such as adjusting the mixing method (high gravity process), adding solvents, using surfactants or surface modifiers, and heating with microwaves.

[0061] As mentioned above, the above are only the preferred embodiments of the present application, and the scope of implementation of the present application cannot be limited. That is, all equivalent changes and modifications made in accordance with the present application should still fall within the scope intended to be protected by the patent of the present application. The present application may also have various other embodiments. Without departing from the spirit and essence of the present application, those skilled in the art can make various corresponding changes and deformations according to the present application, but these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present application.

Claims

1. A non-conductive and highly thermally conductive copper oxide sizing material, the copper oxide sizing material is made of a non-conductive and highly thermally conductive copper oxide sizing material, It is characterized in that Taking the total weight of the copper oxide sizing material as 100wt.%, the copper oxide sizing material comprises: 10 wt.% to 19 wt.% of an aqueous resin, including an epoxy resin, a silane coupling agent, and polyethylene glycol; and 81wt.% to 90wt.% solid content of copper oxide spherical nanopowder, wherein the copper oxide spherical nanopowder is prepared by spray drying granulation: The thermal conductivity of the non-conductive and highly thermally conductive copper oxide glue is between 2.145 and 3.11 W / mK.

2. The non-conductive and highly thermally conductive copper oxide glue as claimed in claim 1, It is characterized in that The copper oxide sizing material comprises 13wt.% to 15wt.% of water-based resin and 85wt.% to 87wt.% of copper oxide spherical nano powder with a solid content.

3. The non-conductive and highly thermally conductive copper oxide glue as claimed in claim 1, It is characterized in that The epoxy resin is selected from at least one of bisphenol A epoxy resin, bisphenol F epoxy resin and cyanuric acid epoxy resin or a combination of more than one thereof.

4. The non-conductive and highly thermally conductive copper oxide glue as claimed in claim 1, It is characterized in that The silane coupling agent is selected from at least one of methacryloxy silane, epoxy silane, and isocyanate silane, or a combination of more than one of these.

5. The non-conductive and highly thermally conductive copper oxide glue as claimed in claim 1, It is characterized in that Taking the total weight of the water-based resin as 100 wt.%, the weight percentages of the epoxy resin: the silane coupling agent: the polyethylene glycol are between 90-95 wt.%, 1-5 wt.%, and 1-9 wt.%.

6. A method for preparing a non-conductive and highly thermally conductive copper oxide sizing material. It is characterized in that include: The copper monoxide nanopowder and the surfactant are mixed in a ratio of 30wt.%:70wt.% to prepare a copper monoxide aqueous solution; The copper oxide aqueous solution is granulated by spray drying to obtain copper oxide spherical nanopowder; Mixing a water-based resin with the copper oxide spherical nanopowder to obtain a mixed rubber material; and Grinding and dispersing the mixed rubber material with three rollers to obtain a non-conductive and high thermal conductive copper oxide rubber material; Wherein, the total weight of the copper oxide sizing material is 100wt.%, and the copper oxide sizing material comprises: 10wt.% to 19wt.% of a water-based resin, which comprises an epoxy resin, a silane coupling agent and polyethylene glycol, and 81wt.% to 90wt.% of a copper oxide spherical nanopowder having a solid content; The thermal conductivity of the non-conductive and highly thermally conductive copper oxide glue is between 2.145 and 3.11 W / mK.

7. The method for preparing the non-conductive and highly thermally conductive copper oxide sizing material according to claim 6, It is characterized in that The copper oxide sizing material comprises 13wt.% to 15wt.% of water-based resin and 85wt.% to 87wt.% of copper oxide spherical nano powder with a solid content.

8. The method for preparing the non-conductive and highly thermally conductive copper oxide sizing material according to claim 6, It is characterized in that The epoxy resin is selected from at least one of bisphenol A epoxy resin, bisphenol F epoxy resin and cyanuric acid epoxy resin or a combination of more than one thereof.

9. The method for preparing the non-conductive and highly thermally conductive copper oxide sizing material according to claim 6, It is characterized in that The silane coupling agent is selected from at least one of methacryloxy silane, epoxy silane, and isocyanate silane, or a combination of more than one of these.

10. The method for preparing the non-conductive and highly thermally conductive copper oxide sizing material according to claim 6, It is characterized in that Taking the total weight of the water-based resin as 100 wt.%, the weight percentages of the epoxy resin: the silane coupling agent: the polyethylene glycol are between 90-95 wt.%, 1-5 wt.%, and 1-9 wt.%.

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