Organic silicon adhesive for nickel-plated copper radiating fin, preparation method and packaging structure

Abstract

The invention provides an organic silicon adhesive for a nickel-plated copper cooling fin, a preparation method and a packaging structure. The organic silicon adhesive is prepared from the following components in percentage by mass: 15 to 20 percent of filling agent, 40 to 60 percent of double-end vinyl silicone oil, 20 to 30 percent of liquid vinyl MQ silicon resin, 3 to 7 percent of polydimethylmethylhydrosiloxane, 0.6 percent of catalyst, 0.55 percent of vinyl type accelerant and 0.1 percent of carbon black. Wherein the double-end vinyl silicone oil is formed by compounding first vinyl silicone oil and second vinyl silicone oil. The viscosity of the organic silicon adhesive is controlled by adjusting the ratio of the first vinyl silicone oil to the second vinyl silicone oil, so that adhesive dispensing operation is facilitated; according to the organic silicon adhesive disclosed by the invention, polydimethylmethylhydrosiloxane and vinyl are initiated to generate a cross-linking curing reaction through a catalyst to form a compact three-dimensional network structure, and meanwhile, the bonding strength between the organic silicon adhesive and a substrate and between the organic silicon adhesive and a nickel-plated copper cooling fin is improved by combining a vinyl accelerant, so that a guarantee is provided for safe operation of an electronic device.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic packaging, and in particular relates to an organic silicon adhesive for a copper-nickel plated heat sink, a preparation method and a packaging structure. Background Art

[0002] In the electronics industry, heat sinks are usually installed in electronic devices to dissipate the heat generated during the operation of the electronic devices into the surrounding air to maintain the long-term operation of the electronic devices. At present, in order to increase the heat dissipation space of electronic devices, electronic devices are usually installed between the heat sink and the substrate to form a heat sink cavity, and the heat sink and the substrate need to be sealed with an adhesive to prevent external impurities such as moisture from entering the heat sink cavity and affecting the performance of the electronic devices.

[0003] Therefore, there is an urgent need to provide a silicone adhesive for a copper-nickel-plated heat sink to improve the bonding strength between the heat sink and the substrate and maintain the connection sealing at high temperatures. Summary of the invention

[0004] The object of the present invention is to provide a silicone adhesive, a preparation method and a packaging structure for a copper-nickel plated heat sink, so as to solve at least one of the above-mentioned technical problems.

[0005] To achieve the above-mentioned purpose, the first aspect of the present invention provides an organic silicone adhesive for a copper-plated nickel heat sink, wherein the organic silicone adhesive comprises the following components in mass percentage: 15% to 20% filler, 40% to 60% double-ended vinyl silicone oil, 20% to 30% liquid vinyl MQ silicone resin, 3% to 7% polydimethylmethylhydrogensiloxane, 0.6% catalyst, 0.55% vinyl-type accelerator, and 0.1% carbon black; wherein the double-ended vinyl silicone oil is compounded by a first vinyl silicone oil and a second vinyl silicone oil, the viscosity of the first vinyl silicone oil is 10000 mPa·s, and the viscosity of the second vinyl silicone oil is 500 mPa·s.

[0006] In the first aspect, the mass percentage of the first ethyl silicone oil is 13% to 32%, and the mass percentage of the second vinyl silicone oil is 13% to 32%.

[0007] In the first aspect, the vinyl content of the first vinyl silicone oil is 0.13 wt %; and the vinyl content of the second vinyl silicone oil is 0.42 wt %.

[0008] In the first aspect, the particle size of the filler is less than 3 μm, and the filler is compounded by fumed silica and silicon powder with different specific surface areas.

[0009] In the first aspect, the dynamic viscosity of the liquid vinyl MQ silicone resin is 6000-8000 CP, the vinyl content of the liquid vinyl MQ silicone resin is 1.4 wt %, and the M / Q ratio of the liquid vinyl MQ silicone resin is 0.8-1.0.

[0010] In the first aspect, the hydrogen content of the polydimethylmethylhydrogensiloxane is 0.75% to 0.88%, and the kinematic viscosity of the polydimethylmethylhydrogensiloxane is 70 to 120 mm 2 / s.

[0011] In the first aspect, the catalyst is a single-component platinum catalyst.

[0012] The second aspect of the present invention provides a method for preparing the organic silicone adhesive for the copper-nickel plated heat sink as described in the first aspect, the preparation method comprising: S1. Add each component into a stirring cup according to their respective mass percentages, and mix them evenly by a first centrifugal stirrer to obtain a first slurry; the mass percentages of the components specifically include: filler 15% to 20%, double-terminal vinyl silicone oil 40% to 60%, liquid vinyl MQ silicone resin 20% to 30%, polydimethylmethylhydrogensiloxane 3% to 7%, catalyst 0.6%, vinyl type accelerator 0.55%, and carbon black 0.1%; S2, transferring the first slurry to a three-roll mill for dispersion treatment to obtain a uniformly dispersed second slurry; S3. Vacuum degassing the second slurry using a second centrifugal mixer to obtain an organosilicon adhesive.

[0013] In the second aspect, the working parameters of the first centrifugal mixer include: stirring time of 90 to 120 s, rotation of 800 r / min, and revolution of 1200 r / min; the working parameters of the three-roll grinder include: feeding gap of 10 μm, and discharging gap of 5 μm; the working parameters of the second centrifugal mixer include: vacuum degassing time of 60 to 80 s, rotation of 800 r / min, and revolution of 1200 r / min.

[0014] The third aspect of the present invention provides a packaging structure, which includes a substrate, an electronic device and a copper-nickel-plated heat sink. The four sides of the copper-nickel-plated heat sink are connected to the substrate through a silicone adhesive. The four sides of the copper-nickel-plated heat sink and the substrate together form a accommodating space. The electronic device is placed in the accommodating space. The silicone adhesive is made by the preparation method of the silicone adhesive for copper-nickel-plated heat sink described in the second aspect.

[0015] Beneficial effects: The present invention provides an organic silicone adhesive for a copper-plated nickel heat sink, wherein the organic silicone adhesive comprises the following components by mass percentage: 15% to 20% of a filler, 40% to 60% of a double-terminal vinyl silicone oil, 20% to 30% of a liquid vinyl MQ silicone resin, 3% to 7% of polydimethylmethylhydrogensiloxane, 0.6% of a catalyst, 0.55% of a vinyl-type accelerator, and 0.1% of carbon black; wherein the double-terminal vinyl silicone oil is compounded by a first vinyl silicone oil and a second vinyl silicone oil, wherein the viscosity of the first vinyl silicone oil is 10000 mPa·s, and the viscosity of the second vinyl silicone oil is 500 mPa·s; Double-ended vinyl silicone oil and liquid vinyl MQ silicone resin are selected as matrix materials to provide mechanical strength for the silicone adhesive. At the same time, the viscosity of the silicone adhesive is controlled by adjusting the ratio of the first vinyl silicone oil to the second vinyl silicone oil to facilitate dispensing operations. The strength of the silicone adhesive and the convenience of dispensing operations are further improved by adding fillers. The cross-linking and curing reaction of polydimethylmethylhydrogensiloxane and vinyl is induced by a catalyst to form a dense three-dimensional network structure. At the same time, a vinyl-type accelerator is combined to improve the bonding strength between the silicone adhesive and the substrate and the copper-plated nickel heat sink, thereby providing protection for the safe operation of electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. 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 creative work.

[0017] Figure 1 The present invention is a flow chart of a method for preparing an organic silicone adhesive for a copper-nickel-plated heat sink in the present application. DETAILED DESCRIPTION

[0018] The present invention will be described in detail below in conjunction with specific implementations 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 implementations and examples are used to illustrate the present invention, rather than to limit the present invention.

[0019] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. In the event of a conflict, the present specification takes precedence.

[0020] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or obtained by existing methods.

[0021] The present application provides an organic silicone adhesive for a copper-plated nickel heat sink, which comprises the following components in mass percentage: 15% to 20% filler, 40% to 60% double-ended vinyl silicone oil, 20% to 30% liquid vinyl MQ silicone resin, 3% to 7% polydimethylmethylhydrogensiloxane, 0.6% catalyst, 0.55% vinyl-type accelerator, and 0.1% carbon black; wherein the double-ended vinyl silicone oil is compounded by a first vinyl silicone oil and a second vinyl silicone oil, the viscosity of the first vinyl silicone oil is 10000 mPa·s, and the viscosity of the second vinyl silicone oil is 500 mPa·s.

[0022] Specifically, the present invention provides an organic silicone adhesive for a copper-plated nickel heat sink, wherein the organic silicone adhesive comprises the following components by mass percentage: 15% to 20% filler, 40% to 60% vinyl silicone oil, 20% to 30% liquid vinyl MQ silicone resin, 3% to 7% polydimethylmethylhydrogensiloxane, 0.6% catalyst, 0.55% vinyl type accelerator, and 0.1% carbon black; wherein the double-terminal vinyl silicone oil is compounded by a first vinyl silicone oil and a second vinyl silicone oil, the viscosity of the first vinyl silicone oil is 10000 mPa·s, and the viscosity of the second vinyl silicone oil is 500 mPa·s ; Double-ended vinyl silicone oil and liquid vinyl MQ silicone resin are selected as matrix materials to provide mechanical strength for the silicone adhesive, and the viscosity of the silicone adhesive is controlled by adjusting the ratio of the first vinyl silicone oil to the second vinyl silicone oil to facilitate dispensing operations; the strength of the silicone adhesive and the convenience of dispensing operations are further improved by adding fillers; a catalyst is used to induce a cross-linking and curing reaction between polydimethylmethylhydrogensiloxane and vinyl to form a dense three-dimensional network structure, and a vinyl-type accelerator is combined to improve the bonding strength between the silicone adhesive and the substrate and the copper-nickel-plated heat sink, thereby providing protection for the safe operation of electronic devices.

[0023] In some possible embodiments, the mass percentage of the first vinyl silicone oil is 13% to 32%, and the mass percentage of the second vinyl silicone oil is 13% to 32%.

[0024] In some possible embodiments, the vinyl content in the first vinyl silicone oil is 0.13 wt %; and the vinyl content in the second vinyl silicone oil is 0.42 wt %.

[0025] Those skilled in the art will appreciate that by adjusting the ratio of the first vinyl silicone oil to the second vinyl silicone oil, the degree of crosslinking and the molecular weight of the crosslinking curing reaction product can be controlled, and thus the mechanical strength of the organic adhesive can be controlled to adapt to the operating environment of the electronic device. In a specific embodiment, the first vinyl silicone oil can be selected from a product model including RH-VI303, and the second vinyl silicone oil can be selected from a product model including RH-VI500E.

[0026] In some possible embodiments, the particle size of the filler is less than 3 μm, and the filler is compounded by fumed silica and silicon powder with different specific surface areas.

[0027] This is because the filler compounded by fumed silica and silicon powder can not only improve the strength and thixotropic coefficient of the organic adhesive, but also be evenly dispersed in the matrix material, so that the organic adhesive has suitable fluidity and is easy to dispensing operation.

[0028] In some possible embodiments, the dynamic viscosity of the liquid vinyl MQ silicone resin is 6000-8000 CP, the vinyl content of the liquid vinyl MQ silicone resin is 1.4 wt %, and the M / Q ratio of the liquid vinyl MQ silicone resin is 0.8-1.0.

[0029] In some possible embodiments, the hydrogen content of the polydimethylmethylhydrogensiloxane is 0.75% to 0.88%, and the kinematic viscosity of the polydimethylmethylhydrogensiloxane is 70 to 120 mm 2 / s.

[0030] Those skilled in the art will appreciate that by adjusting the proportion of the liquid vinyl MQ silicone resin, the degree of crosslinking in the crosslinking curing reaction can be controlled so that the crosslinking curing points are evenly dispersed, thereby improving the tensile strength and mechanical properties of the silicone adhesive. In a specific embodiment, the liquid vinyl MQ silicone resin may be selected from a product model including DT2750, and the polydimethylmethylhydrogensiloxane may be selected from a product model including H802 or H502.

[0031] In some possible embodiments, the catalyst is a single-component platinum catalyst.

[0032] This is because, when a single-component platinum catalyst is used as a catalyst, no inhibitor needs to be added, and the prepared silicone adhesive can be stored at low temperature for a long time and dispensed at room temperature.

[0033] Furthermore, in order to improve the bonding strength between the organic silicone adhesive and the substrate and the copper-plated nickel heat sink, a vinyl type accelerator is added to improve the adhesion between the substrates, so that the prepared organic silicone adhesive can still maintain good sealing properties under long-term high temperatures and has excellent bonding strength. The available models of the vinyl type accelerator include S422.

[0034] Based on a general inventive concept, see Figure 1 The present application also provides a method for preparing the organic silicone adhesive for the copper-nickel plated heat sink as described in the first aspect, the preparation method comprising: S1. Add each component into a stirring cup according to its mass percentage, and mix them evenly by a first centrifugal stirrer to obtain a first slurry; the mass percentage of each component specifically includes: filler 15% to 20%, double-end vinyl silicone oil 40% to 60%, liquid vinyl MQ silicone resin 20% to 30%, polydimethylmethylhydrogensiloxane 3% to 7%, catalyst 0.6%, vinyl type accelerator 0.55%, carbon black 0.1%; wherein the working parameters of the first centrifugal stirrer include: stirring time of 90 to 120 seconds, rotation 800 r / min, revolution 1200 r / min; S2, transferring the first slurry to a three-roll mill for dispersion treatment to obtain a uniformly dispersed second slurry; wherein the working parameters of the three-roll mill include: a feed gap of 10 μm, and a discharge gap of 5 μm; S3, vacuum degassing the second slurry by a second centrifugal mixer to obtain an organic silicone adhesive, wherein the working parameters of the second centrifugal mixer include: vacuum degassing time of 60 to 80 seconds, rotation of 800 r / min, and revolution of 1200 r / min.

[0035] The preparation method of the organic silicone adhesive provided in the present application is simple, easy to dispense, and has excellent bonding strength and thermal stability.

[0036] Based on a general inventive concept, the third aspect of the present invention provides a packaging structure, which includes a substrate, an electronic device and a copper-nickel-plated heat sink. The four sides of the copper-nickel-plated heat sink are connected to the substrate through a silicone adhesive. The four sides of the copper-nickel-plated heat sink and the substrate together form a accommodating space. The electronic device is placed in the accommodating space. The silicone adhesive is made by the preparation method of the silicone adhesive for copper-nickel-plated heat sink described in the second aspect.

[0037] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0038] The distribution ratios of the raw materials in Comparative Examples 1-5 and Examples 1-3 and the test results are shown in Table 1 below: Table 1 Distribution ratio of each group of raw materials and test results The test process of the bonding strength of the silicone adhesive in the present invention is as follows: Fill the heat sink cavity with tape to prevent glue from overflowing into the cavity, and dispense the prepared silicone adhesive onto the four sides of the heat sink (24.5mm×24.5mm) (glue width 1.8mm). Then, attach the heat sink to the green oil substrate with a pressing interval of 16-20um. Place it in an oven for curing at 125℃ / 90min, and finally place it on a thrust machine to test the bonding strength.

[0039] Furthermore, the thermal stability test of the organic silicone adhesive prepared in Example 1 was carried out to test the bonding strength of the organic adhesive at 150° C., as shown in Table 2: Table 2 Thermal stability test results of silicone adhesive From the above table, we can see that: (1) From the experimental data of Comparative Examples 1-3, it can be seen that the addition content of liquid vinyl MQ silicone resin DT2750 is too high, resulting in uneven distribution of crosslinking points of the reaction, which leads to a decrease in the tensile strength of the silicone adhesive; the addition content of liquid vinyl MQ silicone resin DT2750 is too low, resulting in too low crosslinking density of the reaction, and the three-dimensional network structure formed is not sufficient to provide an applicable environment for the silicone adhesive; (2) In Comparative Example 4, only the low-viscosity second vinyl silicone oil RH-VI500E is used, which makes the distribution of the reaction cross-linking points uneven and the cross-linking density too large. Although it can reduce the viscosity of the silicone adhesive, it also reduces the tensile strength of the silicone adhesive, making it unable to resist external pressure and protect the electronic device. Comparative Example 5 uses the high-viscosity second vinyl silicone oil RH-VI303, which can increase the viscosity of the silicone adhesive, but has little effect on the bonding strength. (3) Comparative Example 1 uses hydrogen-based accelerator S421, Example 1 uses vinyl-based accelerator S422, and the proportions of other raw materials are the same, but the bonding strength of the silicone adhesive prepared in Example 1 is significantly enhanced, indicating that the vinyl-based accelerator in the present invention is more conducive to the sealing of electronic devices. At the same time, the viscosity and tensile strength are improved, which is conducive to the dispensing operation; (4) The use of compounded double-terminal vinyl silicone oil and vinyl-type accelerator within the specified range of the present invention in Examples 1-3 can significantly improve the bonding strength of the silicone adhesive, providing basic conditions for the safe operation of electronic devices.

[0040] In summary, the organic silicone adhesive for copper-plated nickel heat sink provided by the present invention has excellent high and low temperature resistance, and can work safely at 150°C for more than 1000 hours without affecting the bonding performance; the organic silicone adhesive of the present invention can be stored at low temperatures and operated at room temperature, which can avoid the waste of organic silicone adhesive; the organic silicone adhesive of the present invention has excellent bonding strength, tensile strength and suitable viscosity, which is convenient for dispensing operations and realizes the safe operation of electronic devices.

[0041] 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 series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements that are inherent to such process, method, article, or apparatus.

[0042] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other 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.

[0043] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A silicone adhesive for a copper-nickel plated heat sink, characterized in that: The silicone adhesive comprises the following components in percentage by mass: 15% to 20% filler, 40% to 60% double-ended vinyl silicone oil, 20% to 30% liquid vinyl MQ silicone resin, 3% to 7% polydimethylmethylhydrogensiloxane, 0.6% catalyst, 0.55% vinyl type accelerator, and 0.1% carbon black; wherein the double-ended vinyl silicone oil is compounded by a first vinyl silicone oil and a second vinyl silicone oil, the viscosity of the first vinyl silicone oil is 10000 mPa·s, and the viscosity of the second vinyl silicone oil is 500 mPa·s.

2. The organic silicon adhesive for copper-nickel plated heat sink according to claim 1, characterized in that: The mass percentage of the first ethyl silicone oil is 13% to 32%, and the mass percentage of the second vinyl silicone oil is 13% to 32%.

3. The organic silicon adhesive for copper-nickel plated heat sink according to claim 2, characterized in that: The vinyl content of the first vinyl silicone oil is 0.13wt%; the vinyl content of the second vinyl silicone oil is 0.42wt%.

4. The organic silicon adhesive for copper-nickel plated heat sink according to claim 3, characterized in that: The particle size of the filler is less than 3 μm, and the filler is compounded by fumed silica and silicon micropowder with different specific surface areas.

5. The organic silicon adhesive for copper-nickel plated heat sink according to claim 4, characterized in that: The dynamic viscosity of the liquid vinyl MQ silicone resin is 6000-8000 CP, the vinyl content of the liquid vinyl MQ silicone resin is 1.4 wt %, and the M / Q ratio of the liquid vinyl MQ silicone resin is 0.8-1.

0.

6. The organic silicon adhesive for copper-nickel plated heat sink according to claim 5, characterized in that: The hydrogen content of the polydimethylmethylhydrogensiloxane is 0.75% to 0.88%, and the kinematic viscosity of the polydimethylmethylhydrogensiloxane is 70 to 120 mm 2 / s.

7. The organic silicon adhesive for copper-nickel plated heat sink according to claim 6, characterized in that: The catalyst is a single-component platinum catalyst.

8. A method for preparing an organic silicon adhesive for a copper-nickel plated heat sink according to any one of claims 1 to 7, characterized in that: The preparation method comprises: S1. Add each component into a stirring cup according to their respective mass percentages, and mix them evenly by a first centrifugal stirrer to obtain a first slurry; the mass percentages of the components specifically include: filler 15% to 20%, double-terminal vinyl silicone oil 40% to 60%, liquid vinyl MQ silicone resin 20% to 30%, polydimethylmethylhydrogensiloxane 3% to 7%, catalyst 0.6%, vinyl type accelerator 0.55%, and carbon black 0.1%; S2, transferring the first slurry to a three-roll mill for dispersion treatment to obtain a uniformly dispersed second slurry; S3. Vacuum degassing the second slurry using a second centrifugal mixer to obtain an organosilicon adhesive.

9. The method for preparing the organic silicon adhesive for copper-nickel plated heat sink according to claim 8, characterized in that: The working parameters of the first centrifugal mixer include: stirring time of 90 to 120 seconds, rotation of 800 r / min, revolution of 1200 r / min; The working parameters of the three-roll mill include: the feed gap is 10 μm, the discharge gap is 5 μm; The working parameters of the second centrifugal mixer include: vacuum degassing time of 60 to 80 seconds, rotation of 800 r / min, and revolution of 1200 r / min.

10. A packaging structure, characterized in that: The packaging structure includes a substrate, an electronic device and a copper-nickel-plated heat sink. The four sides of the copper-nickel-plated heat sink are connected to the substrate through a silicone adhesive. The four sides of the copper-nickel-plated heat sink and the substrate together form a accommodating space. The electronic device is placed in the accommodating space. The silicone adhesive is made by the preparation method of the silicone adhesive for copper-nickel-plated heat sink described in claim 9.

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