CN114350294B - Preparation method of conductive adhesive film for circuit board - Google Patents
Preparation method of conductive adhesive film for circuit board Download PDFInfo
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- CN114350294B CN114350294B CN202110381453.3A CN202110381453A CN114350294B CN 114350294 B CN114350294 B CN 114350294B CN 202110381453 A CN202110381453 A CN 202110381453A CN 114350294 B CN114350294 B CN 114350294B
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Abstract
The invention provides a preparation method of a conductive adhesive film for a circuit board, which relates to the technical field of conductive materials and comprises the steps of modifying conductive particles by using a modifier to obtain modified conductive particles; carrying out surface treatment on the heat-conducting filler by adopting a silane coupling agent to obtain a modified heat-conducting filler; the weight ratio of the large-grain-size heat-conducting filler to the small-grain-size heat-conducting filler is 1:1-2; providing a non-conductive adhesive resin, and grinding the non-conductive adhesive resin, the modified conductive particles and the modified heat-conducting filler to form a master batch; and heating and curing the master batch to form the conductive adhesive film. The preparation method provided by the invention can solve the heat dissipation problem of the heating element on the circuit board, reduce the accumulation effect of the heat conducting filler, reduce the volume resistivity of the adhesive film and gain the electric conductivity of the adhesive film, and improve the holding viscosity, the peeling strength, the gain bonding performance and the sealing performance; the conductive adhesive film has good electric conductivity, heat conductivity and adhesion, and has application prospect in preparing circuit boards or chip packaging.
Description
Technical Field
The invention belongs to the technical field of conductive materials, and particularly relates to a preparation method of a conductive adhesive film for a circuit board.
Background
With the development of social technology, people are pursuing more and more hot for high-tech products, smart phones, electronic products and the like. The requirements for product and technology development are also increasing, and products are continuously required to realize more functions on smaller and smaller external dimensions, so that thinner, smaller and higher packaging density reliability solutions are required to be searched for when semiconductor packaging is carried out, and materials used for manufacturing the ultra-small semiconductor device are further required. Conventional chip package connections typically use materials such as lead-tin solder or conductive silver paste. However, when lead-tin solder packaging is used, the minimum pitch of lead-tin soldering is only 0.65mm; when the conductive silver adhesive material is used for packaging, the phenomena of adhesive climbing on the side of the chip, chip inclination and the like can be caused; these seriously affect the further miniaturization of the chip package and fail to meet the design requirements. In order to realize small size, high miniaturization and densification of multi-chip device design of chip package, research and development of novel connecting materials are required, wherein a mode of using conductive adhesive film materials to replace traditional connecting materials for chip bonding is favored by the semiconductor industry.
The conductive adhesive film is a lead-free connecting material, and after solidification or drying, the adhesive has certain conductive performance, and generally takes matrix resin and conductive filler, namely conductive particles, as main components, and the conductive particles are combined together through the bonding action of the matrix resin to form a conductive path, so that the conductive connection of the adhered material is realized, and the conductive adhesive film provides mechanical connection and electrical connection between the element and a circuit board, thus being gradually and widely applied to various electronic fields such as microelectronic packaging, printed circuit boards, conductive circuit bonding and the like.
Currently, the existing conductive adhesive films are generally manufactured by mixing a large amount of conductive particles in the adhesive, so that the conductive adhesive film can simultaneously provide mechanical connection and electrical connection. In practical application, the conductive adhesive film is adhered between the conductors, and conduction between the conductors is realized by adhering one side of the conductive adhesive film to one of the conductors and adhering the other side of the conductive adhesive film to the other conductor. However, in the implementation process, at least the following problems exist in the prior art: (1) The overlapping rate of conductive particles in the traditional conductive adhesive film is generally low under the influence of a manufacturing process, so that the resistance of the conductive adhesive film is high; (2) Under the condition of high temperature, after the conductive adhesive film is heated, the colloid expands, so that the conductive particles are pulled apart, the overlapping rate of the conductive particles is further reduced, the resistance of the conductive adhesive film is rapidly increased, and even the open circuit failure occurs. Therefore, the conductive adhesive film material and the preparation method thereof are continuously developed and updated to meet the requirements of high-speed high-frequency development and replacement of electronic products, and are always research trends and hot spots in the industry.
Disclosure of Invention
[ problem to be solved by the invention ]
The invention aims to provide a preparation method of a conductive adhesive film for a circuit board, which can reduce the accumulation effect of a heat conducting filler, reduce the volume resistivity of the adhesive film, improve the electric conductivity of the adhesive film, improve the holding viscosity and the peeling strength, and improve the bonding performance and the sealing performance.
Technical scheme
The technical scheme adopted by the invention for achieving the purpose is as follows:
a conductive adhesive film for a wiring board, comprising: the adhesive comprises conductive particles, a heat-conducting filler and non-conductive adhesive resin, wherein the conductive particles and the heat-conducting filler are dispersed in the non-conductive adhesive resin;
the surface of the conductive particle is provided with at least one group of a hydrophobic group and a carboxyl group; the conductive particles are a mixture of flaky, spherical and dendritic particles, and the weight ratio of the flaky, spherical and dendritic particles is 1-2:1:0.5-1;
the heat conducting filler is subjected to surface treatment by a silane coupling agent; the heat conducting filler is divided into a large particle size and a small particle size, the particle size of the large particle size heat conducting filler is 15-35 mu m, and the particle size of the small particle size heat conducting filler is 1-15 mu m;
the thickness of the conductive adhesive film is 5-100 μm. The conductive adhesive film can provide excellent conductivity, can be used for solving the heat dissipation problem of the heating element on the circuit board, has good heat dissipation effect by radiating heat through the adhesive film, has good manufacturability and operability, and can realize the packaging of thinner and smaller chips.
According to the present invention, the adhesive resin comprises the following components in parts by weight: 2-10 parts of CTBN modified epoxy resin, 1-5 parts of acrylic thermoplastic resin, 1-5 parts of latent curing agent and 1-2 parts of toughening rubber.
Further provided is that: the conductive particles are at least one selected from silver particles, copper particles, nickel particles, tin particles, and gold particles.
Further provided is that: the heat conductive filler is at least one selected from zinc oxide, aluminum oxide, magnesium oxide, aluminum nitride, boron nitride and silicon carbide.
Further provided is that: the outer layer of the conductive adhesive film is provided with a release film layer, and the thickness of the release film layer is 20-100 mu m. The release film layer is preferably: PET fluoroplastic release film layer, PET silicone oil release film layer, PET matte release film layer, PE release film layer or PE laminated paper layer. Further, the release film layer is a double-sided release film layer or a single-sided release film layer. Preferably, the double-sided release type is realized, the thickness is preferably 25-50 mu m, and the color is pure white or milky white.
Further provided is that: the thickness of the conductive adhesive film is preferably 20-50 μm. Too thin the adhesive property is lower, too thick the conductivity is poor, and then the quality and the long-term aging resistance of the adhesive film are affected.
On the basis, the invention provides the application of the conductive adhesive film in preparing a circuit board and also provides the application of the conductive adhesive film in chip packaging. Examples of uses include, but are not limited to, high power electronic components, high density integrated circuits, solar panels, lithium batteries, and other battery packs.
The preparation method of the conductive adhesive film for the circuit board provided by the technical purpose of the invention comprises the following steps:
-modifying the conductive particles with a modifying agent to obtain modified conductive particles;
-surface treating the thermally conductive filler with a silane coupling agent to obtain a modified thermally conductive filler; the weight ratio of the large-grain-size heat-conducting filler to the small-grain-size heat-conducting filler is 1:1-2;
-providing a non-conductive adhesive resin and grinding with the modified conductive particles and the modified thermally conductive filler to form a masterbatch;
and heating and curing the master batch to form the conductive adhesive film.
Through the technical scheme, the mode that the conductive particles with high conductivity and the heat-conducting filler are mutually cooperated is adopted, so that the conductivity of the conductive film is improved, the heat-conducting filler can also effectively absorb heat and conduct and diffuse rapidly, the transfer rate of the heat in the adhesive film is improved, and the aim of optimizing the heat-conducting performance of the conductive adhesive film is fulfilled.
According to the present invention, the modifier is at least one selected from pentaerythritol tetrakis (3-mercaptopropionic acid) and mercaptoacetic acid. After the conductive particles are modified, the conductive particles are uniformly dispersed in the adhesive film master batch, and meanwhile, the adhesion degree between the adhesive film and metal and between the adhesive film and silicon wafers is increased, so that excellent adhesive property is provided, and the conductivity of an adhesive film product are also enhanced.
Preferably, the specific implementation method of the conductive particle modification is as follows: immersing conductive particles in a modifier solution with the weight percent of 1-10% for 3-6 hours, washing with tetrahydrofuran for 1-2 times, washing with absolute ethyl alcohol for 1-2 times, and drying to obtain modified conductive particles; the weight ratio of the conductive particles to the modifier solution is 1:20-50; the solvent of the modifier solution is tetrahydrofuran.
According to the present invention, the surface treatment conditions of the above heat conductive filler are as follows: the ultrasonic conditions are high-low frequency alternate working of 30-40 kHz-15-20 kHz, single frequency working time of 30-60s, temperature of 50-70 ℃ and modification time of 20-45min.
According to the invention, the preparation steps of the modified heat-conducting filler are as follows: uniformly mixing the heat conducting filler, the silane coupling agent, the dispersing agent, the water and the ethanol, carrying out surface modification, centrifuging at the rotating speed of 1000-1500r/min, and vacuum drying the solid matters obtained by centrifuging at the temperature of 70-80 ℃ for 2-5h to obtain the heat conducting material.
Further provided is that: the silane coupling agent is n-octyl triethoxysilane or vinyl triethoxysilane. The surface modification is carried out on the heat conducting fillers with different particle sizes, so that the dispersibility of the heat conducting fillers in the master batch is improved, the adhesion degree between the adhesive film and metal and between the adhesive film and silicon wafers can be improved, excellent adhesive property is provided, the heat conducting fillers with different particle sizes are mutually filled, and the electric conductivity and the heat conductivity of the adhesive film product are also enhanced.
Further provided is that: the weight ratio of the heat conducting filler to the silane coupling agent to the dispersing agent to the water to the ethanol is 10:0.1-0.5:0.01-0.05:1-5:10-20; the dispersing agent is a mixture of m-carboxyphenylboronic acid and lithium metaphosphate in a weight ratio of 1:0.2-0.7. The dispersing agent is arranged on the surface of the heat-conducting filler treated by the coupling agent, and can be used for enabling the heat-conducting fillers with different particle diameters to be uniformly dispersed in the master batch to form a stable and uniform master batch system, so that the accumulation effect of the heat-conducting filler is reduced, the volume resistivity of the adhesive film is reduced, and the electric conductivity of the adhesive film is improved; meanwhile, the dispersibility of the heat conducting filler is improved, so that the link tightness between the heat conducting filler and the conductive particles and between the heat conducting filler and the adhesive resin is improved, the cohesive strength of the adhesive film material is improved, and higher holding viscosity and peeling strength are provided, namely the adhesive property and sealing property of the adhesive film are improved.
According to the invention, in the preparation of the above master batch, the milling conditions are as follows: the rotating speed is 200-500r/min, the time is 30-60min, and the vacuumizing and air-exhausting time is 5-10min; the weight ratio of the grinding raw material modified conductive particles to the modified heat-conducting filler to the adhesive resin is 3-5:1-2:5.
Further provided is that: the toughening rubber is one or more selected from acrylic rubber, butyl cyanide rubber, silicon rubber, polyurethane rubber and fluororubber.
Preferably, the specific implementation method of the masterbatch preparation is as follows: mixing the modified conductive particles, the modified heat-conducting filler and the non-conductive adhesive resin, grinding, then sending into vacuumizing equipment, vacuumizing and exhausting bubbles to obtain the master batch.
According to the invention, the specific implementation method of the heat curing is as follows: coating master batch on the surface of the release film layer, heating and curing at 70-100 ℃ to form a conductive adhesive layer, pressing another release film layer on the surface of the conductive adhesive layer, rolling and slitting to obtain the finished product.
The invention also provides a circuit board, which comprises a metal substrate, a printed circuit board and the conductive adhesive film, wherein the printed circuit board is pressed with the metal substrate through the conductive adhesive film.
Further provided is that: the circuit board further comprises an insulating layer, wherein the insulating layer is a cured resin layer, the thickness of the insulating layer is 5-25 mu m, and the surface roughness of the insulating layer is not higher than 200nm. The resin used for preparing the insulating layer has electrical insulation property, and the weight average molecular weight of the resin is 5 ten thousand to 15 ten thousand. Examples are not limited to epoxy resins, maleimide resins, acrylic resins, alicyclic olefin polymers, aromatic polyether polymers, polyimides, and the like.
[ advantageous effects ]
The invention adopts the mutual synergy of the conductive particles and the heat-conducting filler and coexists in the adhesive film, thereby having the following beneficial effects: 1) The conductive particles and the heat-conducting fillers with different particle diameters are mutually filled after being subjected to surface modification, so that the conductivity of the conductive film is synergistically improved, the heat-conducting property is provided, and meanwhile, the adhesive film can also provide excellent adhesive property and sealing property; 2) The preparation method provided by the invention is beneficial to reducing the accumulation effect of the heat conducting filler, further reducing the volume resistivity of the adhesive film and increasing the electric conductivity of the adhesive film, and simultaneously improving the holding viscosity and the peeling strength of the adhesive film, thereby providing more excellent adhesive property and sealing property; 3) The conductive adhesive film can provide high thermal conductivity (the thermal conductivity is more than or equal to 5W/m.k) and higher electrical conductivity (the volume resistivity is less than or equal to 0.003 ohm.cm), has good heat dissipation effect, can provide high bonding strength and interface bonding strength, realizes reliable connection between conductors and effective encapsulation of electrical elements, solves the heat dissipation problem of heating elements on a circuit board, ensures the heat dissipation effect and temperature uniformity of the electrical elements, and is beneficial to prolonging the service life of the electrical elements.
Therefore, the invention is the conductive adhesive film for the circuit board, which has good electric conductivity, heat conductivity and adhesion performance, can solve the heat dissipation problem of the heating element on the circuit board, and has good heat dissipation effect.
Drawings
FIG. 1 shows the volume resistivity and the amplification test results before and after thermal cycling of different conductive adhesive films.
Detailed Description
The technical scheme of the invention is further described in detail below with reference to the specific embodiments and the attached drawings:
as an improvement of the technical scheme, the preparation method can be further optimized, and specific measures are as follows: the master batch is also added with 0.5 to 1 weight percent of melamine monoamide and 1 to 2.5 weight percent of epoxy succinic acid; gain exists between the conductive particles and the modified groups on the surfaces of the conductive particles, so that the connection between the conductive particles is further realized, the overlapping rate of the conductive particles is improved, the electrical impedance is reduced, and the conductive performance of the adhesive film is enhanced; meanwhile, after the epoxy and other annular structures participate in solidification, the damage of thermal circulation and thermal shock environments to conductivity of conductive particles and conductivity of the adhesive film can be effectively reduced, and long-term ageing resistance and conductivity stability of the adhesive film are improved.
Further, the invention also provides a using method of the conductive adhesive film: pre-attaching a conductive adhesive film on a main grid of a polycrystalline silicon wafer, performing hot-pressing adhesion for 0.1-2s at the temperature of 60-70 ℃ and the pressure of 0.1-0.3MPa, peeling off a residual release film, fixing a printed circuit board with corresponding size on the conductive adhesive film, performing hot-pressing adhesion for 0.1-1s at the temperature of 60-70 ℃ and the pressure of 0.1-0.3MPa, and performing hot-pressing adhesion for 3-10s at the temperature of 150-180 ℃ and the pressure of 1.0-1.5MPa to finish connection.
It is to be understood that the foregoing description is intended to be illustrative or exemplary and not limiting, and that changes and modifications may be made by those of ordinary skill in the art within the scope and spirit of the following claims.
Example 1:
the preparation method of the conductive adhesive film for the circuit board comprises the following steps:
1) Modification of conductive particles: immersing conductive particles in a modifier solution with the weight percent of 4.5 for 4.5 hours, washing for 2 times by using tetrahydrofuran, washing for 2 times by using absolute ethyl alcohol, and drying to obtain modified conductive particles; the weight ratio of the conductive particles to the modifier solution is 1:45, the modifier is pentaerythritol tetra (3-mercaptopropionic acid), and the solvent of the modifier solution is tetrahydrofuran; the conductive particles are a mixture of flaky, spherical and dendritic, and are a mixture of silver particles and nickel particles in equal weight ratio, and the weight ratio of flaky, spherical and dendritic in the conductive particles is 1.5:1:0.5;
2) And (3) modifying the heat conducting filler: uniformly mixing a heat conducting filler, a silane coupling agent, a dispersing agent, water and ethanol, carrying out surface modification, centrifuging at a rotating speed of 1500r/min, and vacuum drying the solid matters obtained by centrifuging at 80 ℃ for 3 hours to obtain a modified heat conducting filler; the above surface modification conditions: the ultrasonic conditions are high-low frequency alternating operation of 40 kHz-20 kHz, the single-frequency operation time is 60s, the temperature is 70 ℃, and the modification time is 30min; the silane coupling agent is vinyl triethoxysilane; the dispersing agent is a mixture of m-carboxyphenylboronic acid and lithium metaphosphate in a weight ratio of 1:0.7; the weight ratio of the heat conducting filler to the silane coupling agent to the dispersing agent to the water to the ethanol is 10:0.5:0.05:3.5:15; the heat conducting filler is zinc oxide; the weight ratio of the large-grain-size heat-conducting filler to the small-grain-size heat-conducting filler is 1:1; the particle size of the large-particle-size heat conducting filler is 20-25 mu m, and the particle size of the small-particle-size heat conducting filler is 5-10 mu m;
3) Preparing master batch: mixing the modified conductive particles, the modified heat-conducting filler and the non-conductive adhesive resin, grinding for 45min at the rotating speed of 500r/min, then sending into vacuumizing equipment, vacuumizing and exhausting bubbles for 10min to obtain a master batch; the adhesive resin comprises the following components in parts by weight: 8 parts of CTBN modified epoxy resin, 3 parts of acrylic thermoplastic resin, 2 parts of latent curing agent HX-3932 and 1 part of toughening rubber; the toughening rubber is acrylic rubber; the weight ratio of the modified conductive particles to the modified heat-conducting filler to the adhesive resin is 4:1:5;
4) And (3) heating and curing: coating a master batch with the thickness of 30 mu m on the surface of the release film layer, heating and curing at 80 ℃ to form a conductive adhesive layer, pressing another release film layer on the surface of the conductive adhesive layer, rolling and slitting to obtain a finished product; the release film layer is a PET silicone oil release film layer with the thickness of 50 mu m and the color of pure white.
Example 2:
the preparation method of the conductive adhesive film for the circuit board is different from the embodiment 1 in operation:
in the step 1), the modifier is a mixture of pentaerythritol tetra (3-mercaptopropionic acid) ester and mercaptoacetic acid in a weight ratio of 1:0.5, the conductive particles are a mixture of silver particles, nickel particles and tin particles in an equal weight ratio, and the weight ratio of flaky, spherical and dendritic conductive particles is 1.75:1:0.75;
in step 2), the surface modification conditions are as follows: the ultrasonic conditions are high-low frequency alternate working of 35 kHz-15 kHz, the single-frequency working time is 60s, the temperature is 60 ℃, and the modification time is 45min; the silane coupling agent is n-octyl triethoxysilane; the dispersing agent is a mixture of m-carboxyphenylboronic acid and lithium metaphosphate in a weight ratio of 1:0.4; the weight ratio of the heat conducting filler to the silane coupling agent to the dispersing agent to the water to the ethanol is 10:0.5:0.05:5:20; the heat conducting filler is a mixture of zinc oxide, aluminum oxide and boron nitride, and the weight ratio is 1:1:1; the weight ratio of the large-grain-size heat-conducting filler to the small-grain-size heat-conducting filler is 1:1.3;
in the step 3), the adhesive resin comprises the following components in parts by weight: 7.5 parts of CTBN modified epoxy resin, 4.5 parts of acrylic thermoplastic resin, 3.5 parts of latent curing agent HX-3932 and 2 parts of toughening rubber; the toughening rubber is a mixture of acrylic rubber and silicon rubber in equal weight ratio; the weight ratio of the modified conductive particles to the modified heat-conducting filler to the adhesive resin is 4.5:1.5:5; the remaining operations and steps were the same as in example 1.
Example 3:
the preparation method of the conductive adhesive film for the circuit board is different from the embodiment 2 in operation: step 3) the master batch is also added with 0.75 weight percent of melamine monoamide and 1.75 weight percent of epoxy succinic acid; the remaining operations and steps were the same as in example 2.
Example 4:
the preparation method of the conductive adhesive film for the circuit board is different from the embodiment 2 in operation: in the step 2), the dispersant is m-carboxyphenylboronic acid, and lithium metaphosphate is not added; the remaining operations and steps were the same as in example 2.
Example 5:
the preparation method of the conductive adhesive film for the circuit board is different from the embodiment 2 in operation: in the step 2), the dispersing agent is lithium metaphosphate, and m-carboxyphenylboronic acid is not added; the remaining operations and steps were the same as in example 2.
Example 6:
the preparation method of the conductive adhesive film for the circuit board is different from the embodiment 2 in operation: in step 2), no dispersant was added during the modification of the heat conductive filler, and the rest of the operations and steps were the same as in example 2.
Example 7:
the preparation method of the conductive adhesive film for the circuit board is different from that of the embodiment 3 in that: step 3) the master batch is also added with 0.75 weight percent of melamine monoamide, and epoxy succinic acid is not added; the remaining operations and steps were the same as in example 3.
Example 8:
the preparation method of the conductive adhesive film for the circuit board is different from that of the embodiment 3 in that: step 3) epoxy succinic acid with the weight percent of 1.75 percent is also added into the master batch, and melamine monoamide is not added; the remaining operations and steps were the same as in example 3.
Experimental example 1: conductivity test
1) Conductivity test: under the conditions that the ambient temperature is 23+/-2 ℃ and the humidity is 50+/-5% R.H, the direct-current resistance or the electric conduction of the insulating material is tested by using a four-probe tester (SZT-2A) according to a test method of testing standard ASTM D257-2014, the distance between four probes is 15mm, and the current is 50mA. The samples were conductive films prepared according to the methods of examples 1 to 8, respectively, and had a thickness of 30 μm and a width of 10mm. Each group was set up in 4 replicates and averaged. The results are shown in Table 1.
TABLE 1 results of volume resistivity tests of different conductive films
| Example 1 | Example 2 | Example 3 | Example 4 | |
| Volume resistivity Ohm cm | 0.002317 | 0.001867 | 0.001431 | 0.003167 |
| Example 5 | Example 6 | Example 7 | Example 8 | |
| Volume resistivity Ohm cm | 0.005169 | 0.005369 | 0.001624 | 0.001785 |
The results show that examples 1 and 2 each have a volume resistivity of 0.003Ohm cm or less; comparative example 2 and examples 4-6 have found that the use of the dispersant in the method of example 2 may be advantageous in synergistically promoting uniform dispersion of the thermally conductive filler, reducing the accumulation effect of the thermally conductive filler, thereby reducing the volume resistivity of the adhesive film and increasing its electrical conductivity; comparative examples 2 and 3 and examples 7 and 8 found that the method of example 3 may synergistically enhance the connection between conductive particles such that the overlap ratio of the conductive particles is increased, thereby reducing the electrical resistance and enhancing the conductive properties of the adhesive film.
2) Thermal conductivity test: the solid thermal diffusivity was measured by a flash method according to the test standard ASTM E1461-2013 under conditions of an ambient temperature of 120±5 ℃ and a humidity of 50±5% r.h, and the solid thermal diffusivity was measured using a flash thermoconductor (relaxation-resistant LFA 467). The samples were conductive films prepared according to the methods of examples 1 to 8, respectively, and had a thickness of 30 μm and a width of 10mm. Each group was set up in 4 replicates and averaged. The results are shown in Table 2.
Table 2 results of thermal conductivity testing of different conductive films
| Example 1 | Example 2 | Example 3 | Example 4 | |
| Thermal conductivity W/m.k | 5.864 | 6.214 | 6.572 | 5.961 |
| Example 5 | Example 6 | Example 7 | Example 8 | |
| Thermal conductivity W/m.k | 5.793 | 5.675 | 6.356 | 6.239 |
The results show that examples 1 and 2 each have a thermal conductivity of 5W/mK or more; comparative example 2 and examples 4-6 find that the use of the dispersant in the process of example 2 may be advantageous in synergistically promoting uniform dispersion of the thermally conductive filler, reducing the effect of accumulation of the thermally conductive filler, and thus providing better thermal conductivity.
Experimental example 2: aging resistance and conductivity stability test
The test method comprises the following steps: the samples were conductive films prepared according to the methods of examples 2, 3 and examples 7, 8, respectively, and had a thickness of 30 μm and a width of 10mm. The alternating thermal cycle is respectively carried out at the constant temperature and humidity (40+/-5% R.H) of-40 ℃ and 85 ℃, namely-40 ℃ to 85 ℃ to-40 ℃, the constant temperature time under different temperature conditions is 15min, the total cycle of low temperature to high temperature is 1, and 500 cycles are carried out in the test period. The volume resistivity before and after the thermal cycle was tested and compared in the method of experimental example 1, and the increase thereof was calculated. Each group was set up in 4 replicates and averaged. The results are shown in FIG. 1.
FIG. 1 shows the volume resistivity and the amplification test results before and after thermal cycling of different conductive adhesive films. The results show that after alternating thermal cycling and thermal shock, the volume resistivity of each sample rises, which indicates that the thermal cycling has negative influence and damage to the conductivity of the adhesive film; the comparison found that the amplification of example 2 was 14.94%, example 3 was 10.06%, example 7 was 14.10%, and example 8 was 12.89%; the comparison shows that the method of the embodiment 3 can cooperatively improve the long-term ageing resistance and the conductive stability of the adhesive film, so that the adhesive film can effectively reduce the damage of thermal cycle and thermal shock environment to the conductivity of conductive particles and the conductive property of the adhesive film, prolong the service life of the adhesive film, expand the application range of the adhesive film and have economic benefit and popularization value.
Experimental example 3: determination of adhesive Property
The test method comprises the following steps: the samples were conductive films prepared according to the methods of example 2 and examples 4 to 6, respectively, and had a thickness of 30 μm and a width of 10mm. The conductive adhesive film is pre-pasted on a main grid of a polycrystalline silicon wafer by using a hot press (pre-pasting temperature 70 ℃, pre-pasting pressure 0.2MPa and pre-pasting time 1 s), then the residual release film is peeled off, then the welding strip, the conductive adhesive film and the polycrystalline silicon wafer which correspond to the sizes are sequentially pressed (the pressing temperature 70 ℃, the pressing pressure 0.2MPa and the pressing time 5 s), then the hot press is carried out for 5s under the conditions of 150 ℃ and the pressure 1.0MPa, the connection is completed, the end part of the welding strip is bent at 180 degrees, and the welding strip is fixed on a clamp of a tension machine, and 180-degree stretching measurement of the peeling strength is carried out at a stretching speed of 30 mm/s. Each group was set up in 4 replicates and averaged. The results are shown in Table 3.
TABLE 3 results of peel strength test of different conductive films
| Example 2 | Example 4 | Example 5 | Example 6 | |
| 180 DEG peel strength N/1.5mm | 1.02 | 0.89 | 0.82 | 0.76 |
The results show that the peel strength of example 2 is significantly improved compared with examples 4-6, and demonstrate that the use of the dispersing agent in the method of example 2 may improve the dispersibility of the heat conductive filler and the link tightness between the heat conductive filler and the adhesive resin, so that the cohesive strength of the adhesive film material is improved, thereby providing higher holding viscosity and peel strength, and significantly improving the adhesive property and sealing property of the adhesive film.
The conventional technology in the above embodiments is known to those skilled in the art, and thus is not described in detail herein.
The above embodiments are merely for illustrating the present invention and not for limiting the same, and various changes and modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions are also within the scope of the present invention, which is defined by the claims.
Claims (4)
1. A conductive adhesive film for a wiring board, comprising: an electroconductive particle, a heat conductive filler, and a nonconductive adhesive resin, the electroconductive particle, the heat conductive filler being dispersed in the nonconductive adhesive resin; the adhesive resin comprises the following components in parts by weight: 2-10 parts of CTBN modified epoxy resin, 1-5 parts of acrylic thermoplastic resin, 1-5 parts of latent curing agent and 1-2 parts of toughening rubber;
the surface of the conductive particle is provided with at least one group of a hydrophobic group and a carboxyl group; the conductive particles are a mixture of flaky, spherical and dendritic particles, and the weight ratio of the flaky, spherical and dendritic particles is 1-2:1:0.5-1;
the heat conducting filler is divided into a large particle size and a small particle size, wherein the particle size of the large particle size heat conducting filler is 15-35 mu m, and the particle size of the small particle size heat conducting filler is 1-15 mu m;
the thickness of the conductive adhesive film is 5-100 mu m; the preparation method of the conductive adhesive film for the circuit board comprises the following steps:
-modifying the conductive particles with a modifying agent to obtain modified conductive particles; the preparation method of the modified conductive particles comprises the following steps: immersing conductive particles in a modifier solution with the weight percent of 1-10% for 3-6 hours, washing with tetrahydrofuran for 1-2 times, washing with absolute ethyl alcohol for 1-2 times, and drying to obtain modified conductive particles; the weight ratio of the conductive particles to the modifier solution is 1:20-50; the solvent of the modifier solution is tetrahydrofuran; the modifier is at least one of pentaerythritol tetra (3-mercaptopropionic acid) and thioglycollic acid;
-surface treating the thermally conductive filler with a silane coupling agent to obtain a modified thermally conductive filler; the preparation steps of the modified heat conduction filler are as follows: uniformly mixing a heat conducting filler, a silane coupling agent, a dispersing agent, water and ethanol, carrying out surface modification, centrifuging, and vacuum drying a solid substance obtained by centrifuging to obtain the heat conducting material; the weight ratio of the heat conducting filler to the silane coupling agent to the dispersing agent to the water to the ethanol is 10:0.1-0.5:0.01-0.05:1-5:10-20; the weight ratio of the large-grain-size heat-conducting filler to the small-grain-size heat-conducting filler is 1:1-2; the dispersing agent is a mixture of m-carboxyphenylboronic acid and lithium metaphosphate in a weight ratio of 1:0.2-0.7;
-providing a non-conductive adhesive resin and grinding with the modified electrically conductive particles and the modified thermally conductive filler to form a masterbatch;
heating and curing the master batch to form a conductive adhesive film;
the master batch is also added with 0.5 to 1 weight percent of melamine monoamide and 1 to 2.5 weight percent of epoxy succinic acid.
2. The electroconductive adhesive film for a wiring board according to claim 1, wherein: the surface treatment conditions of the heat conducting filler are as follows: the ultrasonic conditions are high-low frequency alternate working of 30-40 kHz-15-20 kHz, single frequency working time of 30-60s, temperature of 50-70 ℃ and modification time of 20-45min.
3. The electroconductive adhesive film for a wiring board according to claim 1, wherein: in the preparation of the master batch, the grinding conditions are as follows: the rotating speed is 200-500r/min, the time is 30-60min, and the vacuumizing and air-exhausting time is 5-10min; the weight ratio of the grinding raw material modified conductive particles to the modified heat-conducting filler to the adhesive resin is 3-5:1-2:5.
4. A wiring board comprising a metal substrate, a printed wiring board and the conductive adhesive film for a wiring board according to claim 1, wherein the printed wiring board is laminated with the metal substrate through the conductive adhesive film.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0652715A (en) * | 1992-07-30 | 1994-02-25 | Fuji Kobunshi Kogyo Kk | Anisotropic conductive adhesive composite |
| JPH06112095A (en) * | 1992-09-25 | 1994-04-22 | Elna Co Ltd | Manufacture of solid-state electrolytic capacitor |
| JP2004253476A (en) * | 2003-02-18 | 2004-09-09 | Lintec Corp | Wafer dicing bonding sheet and process for manufacturing semiconductor device |
| JP2007002089A (en) * | 2005-06-23 | 2007-01-11 | Nissan Motor Co Ltd | Method for producing metal oxide particle composite, resin composition and method for producing resin composition |
| CN1950912A (en) * | 2004-12-16 | 2007-04-18 | 住友电气工业株式会社 | Adhesive for connecting circuit |
| KR20100067560A (en) * | 2008-12-11 | 2010-06-21 | 제일모직주식회사 | Fast curable anisotropic conductive film composition, fast curable anisotropic conductive film using the composition |
| CN102660213A (en) * | 2012-06-08 | 2012-09-12 | 焦作市卓立烫印材料有限公司 | Surface treatment method of heat-conducting filler for epoxy heat-conducting adhesive |
| CN104804687A (en) * | 2015-04-13 | 2015-07-29 | 深圳广恒威科技有限公司 | Conductive die bond glue solution, conductive die bond glue film, preparation methods and applications |
| CN106753133A (en) * | 2016-12-30 | 2017-05-31 | 中国科学院深圳先进技术研究院 | A kind of conductive silver glue and its production and use |
| CN107142029A (en) * | 2017-06-01 | 2017-09-08 | 昆山市工业技术研究院有限责任公司 | A kind of anisotropic conductive film and its preparation method and application |
| CN108300360A (en) * | 2016-10-10 | 2018-07-20 | 昆山雅森电子材料科技有限公司 | Profiled metal particle conductive glued membrane and preparation method thereof |
| CN108913047A (en) * | 2018-07-26 | 2018-11-30 | 深圳广恒威科技有限公司 | Conductive die bond bonding glue, high thermal conductivity conductive adhesive film and preparation method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6517588B2 (en) * | 2015-05-27 | 2019-05-22 | デクセリアルズ株式会社 | Thermosetting adhesive sheet and method of manufacturing semiconductor device |
-
2021
- 2021-04-09 CN CN202110381453.3A patent/CN114350294B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0652715A (en) * | 1992-07-30 | 1994-02-25 | Fuji Kobunshi Kogyo Kk | Anisotropic conductive adhesive composite |
| JPH06112095A (en) * | 1992-09-25 | 1994-04-22 | Elna Co Ltd | Manufacture of solid-state electrolytic capacitor |
| JP2004253476A (en) * | 2003-02-18 | 2004-09-09 | Lintec Corp | Wafer dicing bonding sheet and process for manufacturing semiconductor device |
| CN1950912A (en) * | 2004-12-16 | 2007-04-18 | 住友电气工业株式会社 | Adhesive for connecting circuit |
| JP2007002089A (en) * | 2005-06-23 | 2007-01-11 | Nissan Motor Co Ltd | Method for producing metal oxide particle composite, resin composition and method for producing resin composition |
| KR20100067560A (en) * | 2008-12-11 | 2010-06-21 | 제일모직주식회사 | Fast curable anisotropic conductive film composition, fast curable anisotropic conductive film using the composition |
| CN102660213A (en) * | 2012-06-08 | 2012-09-12 | 焦作市卓立烫印材料有限公司 | Surface treatment method of heat-conducting filler for epoxy heat-conducting adhesive |
| CN104804687A (en) * | 2015-04-13 | 2015-07-29 | 深圳广恒威科技有限公司 | Conductive die bond glue solution, conductive die bond glue film, preparation methods and applications |
| CN108300360A (en) * | 2016-10-10 | 2018-07-20 | 昆山雅森电子材料科技有限公司 | Profiled metal particle conductive glued membrane and preparation method thereof |
| CN106753133A (en) * | 2016-12-30 | 2017-05-31 | 中国科学院深圳先进技术研究院 | A kind of conductive silver glue and its production and use |
| CN107142029A (en) * | 2017-06-01 | 2017-09-08 | 昆山市工业技术研究院有限责任公司 | A kind of anisotropic conductive film and its preparation method and application |
| CN108913047A (en) * | 2018-07-26 | 2018-11-30 | 深圳广恒威科技有限公司 | Conductive die bond bonding glue, high thermal conductivity conductive adhesive film and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| The physiological activity of urea, boric and carboxylic acids.;SUKHOVA, S. I.;Agrokhimiya(第2期);96-99 * |
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