CN112122822B

CN112122822B - Anisotropic conductive welding glue, preparation method thereof and integrated preparation device

Info

Publication number: CN112122822B
Application number: CN202010912730.4A
Authority: CN
Inventors: 朱玲; 吴懿平; 吕卫文; 祝超
Original assignee: Shenzhen Yuanxin Guanglu Technology Co ltd
Current assignee: Shenzhen Yuanxin Guanglu Technology Co ltd
Priority date: 2020-09-02
Filing date: 2020-09-02
Publication date: 2021-03-26
Anticipated expiration: 2040-09-02
Also published as: CN112122822A

Abstract

The invention relates to an anisotropic conductive welding adhesive, which comprises tin-bismuth-silver solder balls, an adhesive, high polymer resin, gap particles and an auxiliary additive; the preparation method comprises the following steps: placing the reactor in a protective gas environment, sequentially adding the components into the reactor, fully mixing, performing differential settlement, and finally adding a curing agent and an auxiliary additive for vacuum defoaming; the preparation device comprises an inner operation cavity and an outer environment cavity, wherein the inner operation cavity comprises a differential base and a fusion chamber, a rotary shearing feeding pipe is installed in the fusion chamber, the differential base comprises a hydraulic telescopic support, a chassis is fixedly installed at the top of the hydraulic telescopic support, and a plurality of vibrating pieces which are uniformly distributed and are mutually independent are installed on the chassis; the invention disperses the low melting point tin-bismuth-silver solder balls in the adhesive to form the anisotropic conductive welding paste, has simple preparation process, realizes seamless processing by the integrated preparation device and improves the product quality.

Description

Anisotropic conductive welding glue, preparation method thereof and integrated preparation device

Technical Field

The invention relates to an anisotropic conductive adhesive, a preparation method thereof and an integrated preparation device, and belongs to the technical field of electronic components.

Background

As a method of mounting an LED element on a package substrate, a flip chip process (FC) is beginning to be widely used. The existing connecting materials mainly comprise two types of soldering paste and conductive adhesive, and the two methods are both used for coating a certain amount of connecting materials at the positions of the bonding pads of the substrate to realize connection. With the size of electronic components becoming smaller and smaller, the spacing between electrodes on the components reaches below 200um, and the situation of short circuit between the electrodes is easy to occur by adopting a soldering paste silk-screen process or an adhesive dispensing process, so that the application of anisotropic conductive adhesive to the fine-spacing connection can be considered.

In the small-spacing LED (or miniLED) packaging connection, a soldering paste printing process or an adhesive dispensing process is adopted as a connection process, so that the efficiency is low, the reliability is not high, and the method cannot be applied to industrial production in a large scale. In actual use, the connection between the element and the substrate is realized only through physical contact generated after the conductive particles are flattened, the connection resistance of the anisotropic conductive adhesive is large, and the package connection of power devices such as LEDs cannot be met.

In addition, in the prior art, the preparation of the anisotropic conductive adhesive is to directly prepare the ingredients in a natural environment, then simply mix the ingredients uniformly, and directly cure the ingredients after mixing uniformly to obtain the anisotropic conductive adhesive, but the preparation method has the defects in the process: if the cleanness degree in the material proportioning process cannot be ensured in the natural environment, impurities in the natural environment can easily enter to influence the quality of the finally formed anisotropic conductive adhesive, meanwhile, the material proportioning process in a non-protective gas environment is easy to cause the oxidation of micro explosive particles, the prepared anisotropic conductive adhesive after uniform mixing is microscopic, the mixing degree among particles is not high, the anisotropic conductive capability of the anisotropic conductive adhesive is influenced, and the anisotropic difference is not obvious due to the absence of difference in the macroscopic view, so that the sharp comparison cannot be formed in different directions, and the preparation process cannot meet the customization requirements in the process.

In actual preparation, because the requirements of the preparation process of the anisotropic conductive adhesive are high, when the requirements of the process are needed to be customized, the anisotropic conductive adhesive is often matched through a plurality of devices, however, the existing devices are mutually independent, when the production line is carried out, on one hand, the production process of the anisotropic conductive adhesive is interrupted, partial coagulation may be caused in the process, and the subsequent quality is affected, on the other hand, the interruption of each step may cause the natural difference of the semi-finished product to settle or separate out, and the semi-finished product cannot be recovered in the subsequent process, so that the normal production of the anisotropic conductive adhesive may be affected.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides the anisotropic conductive welding paste, the preparation method thereof and the integrated preparation device, the anisotropic conductive welding paste produced based on the process and the device can realize metallurgical connection of solder particles with electrodes and bonding pads, the connection resistance is lower, the reliability is better, the anisotropic conductive welding paste is suitable for connection of fine-pitch components and substrates, the integrated preparation device is simple to operate and high in integration degree, the possibility of oxidation in the preparation link of the anisotropic conductive welding paste can be greatly reduced, the welding reliability is ensured, meanwhile, the device can fully mix the welding paste, the small explosive particles are uniformly dispersed, and the fine-pitch welding capability is ensured.

In order to achieve the purpose, the invention adopts the technical scheme that:

an anisotropic conductive welding adhesive comprises tin-bismuth-silver solder balls, an adhesive, high polymer resin, interstitial particles and an auxiliary additive;

the tin-bismuth-silver solder balls are dispersed in an adhesive, and the adhesive comprises an epoxy resin and a curing agent.

As a preferred embodiment of the anisotropic conductive adhesive of the present invention, in the tin-bismuth-silver solder ball, the tin content is 42% to 80%, the bismuth content is 18% to 58%, and the silver content is 0% to 2%;

the volume fraction of the tin-bismuth-silver solder ball is 5% -15%, the particle size is 1-30 um, and the melting point is 139-204 ℃.

In a preferred embodiment of the anisotropic conductive adhesive according to the present invention, the epoxy resin is an alicyclic epoxy resin, and the curing agent is at least one of a modified cationic curing agent and an acid anhydride curing agent.

As a preferred embodiment of the anisotropic conductive adhesive of the present invention, the alicyclic epoxy resin is a halogen-free alicyclic epoxy resin or an unsaturated hydrocarbon-based epoxy resin, and the modified cationic curing agent is a modified BF3 complex.

As a preferred embodiment of the anisotropic conductive adhesive according to the present invention, the polymer resin is at least one of a phenoxy resin and an acrylic resin; the gap particles are at least one of nickel micro powder, silicon micro powder and alumina micro powder, and the particle size of the gap particles is 0.5-5 um; the auxiliary additive is at least one of silane coupling agent, filler, ultraviolet absorbent and antioxidant.

In a preferred embodiment of the anisotropic conductive adhesive of the present invention, the mass of the sn-bi-ag solder ball is 20 to 50 parts by mass, the mass of the epoxy resin is 50 to 79 parts by mass, the mass of the curing agent is 1 to 10 parts by mass, the mass of the polymer resin is 0 to 50 parts by mass, the mass of the interstitial particles is 0 to 20 parts by mass, and the mass of the auxiliary agent is 0 to 10 parts by mass, based on 100 parts by mass of the adhesive.

In a second aspect, the present invention provides a method for preparing the anisotropic conductive adhesive, including the following steps:

placing the reactor in a protective gas environment;

adding a solvent into a reactor, feeding epoxy resin and high polymer resin into the reactor, and adding tin-bismuth-silver solder balls and interstitial particles after the epoxy resin and the high polymer resin are dissolved in the solvent;

feeding materials into the reactor, vibrating the reactor in a local partition mode and differential rotation stirring, standing, and vibrating the reactor in a designated area according to designated frequency during standing to enable the uniformly dispersed mixed solution to be subjected to differential settlement;

and adding a curing agent after uniform dispersion and differential settlement, adding an auxiliary additive, and then performing vacuum defoaming to obtain the anisotropic conductive adhesive.

In a third aspect, the invention provides an integrated preparation device of the preparation method, which comprises an inner operation cavity and an outer environment cavity, wherein the inner operation cavity and the outer environment cavity are fixedly connected through a U-shaped frame, the inner operation cavity and the outer environment cavity are separated through a separation plate fixedly arranged at the top of the U-shaped frame to form two independent cavities, and air pipes are respectively arranged in the inner operation cavity and the outer environment cavity;

the inner operation cavity comprises a differential base arranged at the bottom of the U-shaped frame, a fusion chamber is fixedly arranged on the differential base, two shielding covers are movably arranged above the fusion chamber in a clamping manner, a rotary shearing feeding pipe is arranged between the two shielding covers through a bearing, and a plurality of stirring rods which are not uniformly distributed are fixedly arranged on the outer wall of the rotary shearing feeding pipe positioned in the inner operation cavity;

the hydraulic telescopic support is fixedly arranged at the top of the hydraulic telescopic support, the telescopic variable length of the hydraulic telescopic support is greater than the length of the rotary shearing feeding pipe extending to the inner operation cavity, and a plurality of vibrating pieces which are uniformly distributed and are mutually independent are arranged on the chassis.

As a preferred embodiment of the integrated preparation device of the present invention, the rotary shearing feed pipe sequentially passes through the shielding cover, the isolation plate and the outer environment cavity from inside to outside, and bearings are disposed at the joints of the rotary shearing feed pipe, the isolation plate and the outer environment cavity, and a driving motor is fixedly mounted on the outer environment cavity and connected with the rotary shearing feed pipe through a bevel gear set.

As a preferred embodiment of the integrated preparation apparatus of the present invention, the end of the rotary shearing feeding pipe extends to the bottom of the internal operation cavity, a material distribution port is disposed on a side surface of the bottom end of the rotary shearing feeding pipe, a material guide plate in a curved surface is fixedly mounted inside the material distribution port, an angle of the curved surface of the material guide plate is adjusted by a deflector rod disposed at the bottom of the material guide plate, and the material guide plate is tangent to the inner wall of the rotary shearing feeding pipe.

Compared with the prior art, the invention has the beneficial effects that:

(1) the low-melting-point tin-bismuth-silver solder balls are dispersed in the adhesive to form the anisotropic conductive adhesive, so that the application range of the low-temperature solder and the conductive adhesive is expanded; the modified cationic curing agent is used, so that the function of welding assistance can be achieved; the nickel powder, the silicon powder or the aluminum oxide powder are filled into the anisotropic conductive welding paste to be used as support particles, so that the tin-bismuth-silver solder balls and the epoxy resin are prevented from being completely extruded by the electrodes, and the heat conductivity of the anisotropic conductive welding paste can be improved; the metallurgical connection is formed between the electrode and the substrate through the gap particles with small particle sizes, so that smaller connection resistance can be obtained, the phenomenon of short circuit between the electrodes is avoided, and the connection reliability is improved.

(2) The anisotropic conductive adhesive simplifies the flip chip connection process, is suitable for packaging of small-pitch LEDs, miniLEDs and other elements, can realize high-reliability connection between electrodes of the elements and a substrate, solves the technical problem of printing of fine-pitch electronic circuit substrates, and has the characteristics of simple operation and convenient use.

(3) The invention fuses the whole preparation process through the integrated preparation device, realizes seamless connection of all processes, cannot be negatively influenced by the state and the property of a product during process conversion, keeps the stability of a semi-finished product during process conversion, and can improve the property of the anisotropic conductive adhesive according to the process requirements, thereby artificially intervening the anisotropy of the anisotropic conductive adhesive and meeting the requirements of different processes.

Drawings

FIG. 1 is a sectional view of a connection structure of an electronic component using the anisotropic conductive adhesive of the present invention;

FIG. 2 is a schematic view of the overall structure of the integrated manufacturing apparatus of the present invention;

FIG. 3 is a schematic view of the inner operating chamber of the present invention.

Wherein:

10-LED chip, 20-electrode, 30-anisotropic conductive adhesive, 40-bonding pad, and 50-substrate;

1-an inner operating cavity; 2-external environment chamber; 3-U-shaped frame; 4-a separation plate; 5-air pipe; 6-driving a motor; 7-bevel gear set;

101-a differential base; 102-a fusion chamber; 103-a shielding cover; 104-a rotary shear feed tube; 105-a stir bar; 106-hydraulic telescopic support; 107-chassis; 108-a vibrating plate; 109 material dividing port; 110-guide plate.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to the accompanying drawings and specific embodiments.

The invention provides anisotropic conductive welding glue, which comprises tin-bismuth-silver solder balls, an adhesive, high polymer resin, gap particles and an auxiliary additive;

In the tin-bismuth-silver solder ball, the tin content is 42% -80%, the bismuth content is 18% -58%, and the silver content is 0% -2%; the volume fraction of the tin-bismuth-silver solder ball is 5% -15%, the particle size is 1-30 um, and the melting point is 139-204 ℃.

The epoxy resin is alicyclic epoxy resin, and the curing agent is at least one of modified cationic curing agent and anhydride curing agent. The alicyclic epoxy resin is halogen-free alicyclic epoxy resin or unsaturated hydrocarbon epoxy resin, and the modified cationic curing agent is a modified BF3 complex. The polymer resin is at least one of phenoxy resin and acrylic resin; the gap particles are at least one of nickel micro powder, silicon micro powder and alumina micro powder, and the particle size of the gap particles is 0.5-2 um; the auxiliary additive is at least one of silane coupling agent, filler, ultraviolet absorbent and antioxidant.

The mass of the tin-bismuth-silver solder ball is 20-50 parts by mass, the mass of the epoxidized resin is 50-79 parts by mass, the mass of the curing agent is 1-10 parts by mass, the mass of the high polymer resin is 0-50 parts by mass, the mass of the interstitial particles is 0-20 parts by mass, and the mass of the auxiliary additive is 0-10 parts by mass, relative to 100 parts by mass of the solder paste.

The anisotropic conductive adhesive is added with gap particles to play a supporting role. The invention disperses the small-grain-size low-temperature tin-bismuth-silver solder balls in the adhesive system to form anisotropic conductive adhesive, and the solder particles melt and wet the connecting surface during the hot pressing process to form metallurgical connection between the electrode and the bonding pad, thereby obtaining lower connecting resistance and higher connecting strength. When the solder forms metallurgical connection, resin matrixes in the anisotropic conductive solders are solidified, and other parts of the solder connection form mechanical connection through the adhesives.

Example 1

An anisotropic conductive adhesive, the preparation method comprises: uniformly mixing 1g of alicyclic epoxy resin A and 0.2g of phenoxy resin B in a solvent, adding 0.8g of tin-bismuth-silver solder balls with the particle size of 2-8 um, wherein the volume fraction of the tin-bismuth-silver solder balls is 0.2g of nickel micropowder powder with the median particle size of 2um, uniformly dispersing, adding 0.1g of modified BF3 complex and 0.05g of glutaric anhydride, finally adding 0.02g of silane coupling agent A151 vinyl triethoxysilane and 0.02g of defoamer polysiloxane solution, uniformly mixing, and defoaming in vacuum to obtain the anisotropic conductive welding adhesive.

Will anisotropic electric conduction welding glue evenly coats on the experiment base plate, there is 180um 100 um's square bonding pad on the experiment base plate, and the bonding pad interval is 50um, adopts hot pressing technology to be connected LED chip and base plate, as shown in figure 1.

Comparative example 1

The grain diameter of the tin-bismuth-silver solder ball is 15-30 um, the median grain diameter of the nickel micro powder is 10um, the rest components and the preparation method are the same as those in the embodiment 1, and the curing method is the same as that in the embodiment 1.

The average contact resistance measured by the four-probe method in example 1 was 5 milliohms, and there was no short circuit between the electrodes. The average contact resistance in comparative example 1 was 2 milliohms, but a short circuit phenomenon occurred between the electrodes. The result shows that the anisotropic conductive adhesive can form effective and reliable connection and is suitable for connecting a chip with an electrode spacing smaller than 50um and a substrate.

Example 2

An anisotropic conductive adhesive, the preparation method comprises: uniformly mixing 1g of alicyclic epoxy resin A and 0.2g of acrylic resin C in a solvent, adding 0.5g of tin-bismuth-silver solder balls with the particle size of 2-8 um, wherein the volume fraction of the tin-bismuth-silver solder balls is 0.2g of nickel micropowder powder with the median particle size of 2um, uniformly dispersing, adding 0.1g of modified BF3 complex and 0.05g of glutaric anhydride, finally adding 0.02g of silane coupling agent A151 vinyl triethoxysilane and 0.02g of defoamer polysiloxane solution, uniformly mixing, and defoaming in vacuum to obtain the anisotropic conductive welding adhesive.

Will on the experiment base plate was evenly coated to anisotropic electrically conductive bonding glue, there was 180um 100 um's square pad on the experiment base plate, the pad interval is 50um, adopts hot pressing technology to be connected LED chip and base plate.

Comparative example 2

0.7g of tin-bismuth-silver solder balls are added on the basis of the example 2, nickel micro powder is not added, the other components and the preparation method are the same as the example 2, and the curing method is the same as the example 2.

In example 2, the initial average contact resistance was 6 milliohms as measured by the four-probe method, and the resistance remained unchanged after the high temperature and high humidity test. The initial average contact resistance in comparative example 2 was 20 milliohms, and the rear portion was electrically disconnected after the high temperature and high humidity test. The result shows that the filling particles which play a supporting role are added into the anisotropic conductive adhesive, so that the connection performance can be improved, and the reliability can be improved.

Example 3

Comparative example 3

The modified imidazole curing agent is changed into a common latent curing agent on the basis of the example 3, the other components and the preparation method are the same as the example 3, and the curing method is the same as the example 3.

In example 3, the initial average contact resistance was 8 milliohms as measured by the four-probe method, and the shear strength was 5MPa as measured by the push-pull tester. The initial average contact resistance in comparative example 3 was 15 milliohms and the shear strength was 4MPa as measured by a push-pull tester. The result shows that the modified curing agent can effectively improve the connection strength and improve the conductivity.

Example 4

An anisotropic conductive adhesive, the preparation method comprises: uniformly mixing 1g of alicyclic epoxy resin A in a solvent, adding 0.5g of tin-bismuth-silver solder balls with the grain diameter of 2-4 um, wherein the volume fraction of the tin-bismuth-silver solder balls is 5%, adding 0.1g of nickel micropowder powder with the median grain diameter of 0.5um, uniformly dispersing, adding 0.001g of latent modified imidazole curing agent, finally adding a proper amount of silane coupling agent and defoaming agent, uniformly mixing, and defoaming in vacuum to obtain the anisotropic conductive welding adhesive.

And uniformly coating the anisotropic conductive welding glue on an experimental substrate, wherein square bonding pads of 100um to 20um are arranged on the experimental substrate, the spacing between the bonding pads is 60um, and the 0404micro-LED chip is connected with the substrate by adopting a hot-pressing process.

In example 5, the initial average contact resistance was 5 milliohms as measured by the four-probe method, no short circuit occurred between the electrodes, the resistance remained unchanged after the high temperature and high humidity test, and the shear strength was 5MPa as measured by the push-pull force tester. The result shows that the anisotropic conductive adhesive disclosed by the invention can form effective and reliable connection, is suitable for connecting a chip with an electrode spacing smaller than 50um and a substrate, and is improved in conductivity.

Example 5

An anisotropic conductive adhesive, the preparation method comprises: uniformly mixing 1g of alicyclic epoxy resin A and 0.2g of acrylic resin C in a solvent, adding 0.5g of tin-bismuth-silver solder balls with the particle size of 6-10 um, wherein the volume fraction of the tin-bismuth-silver solder balls is 15%, adding 0.1g of nickel micropowder powder with the median particle size of 2um, uniformly dispersing, adding 0.5g of latent modified imidazole curing agent, finally adding a proper amount of silane coupling agent and defoaming agent, uniformly mixing, and defoaming in vacuum to obtain the anisotropic conductive welding adhesive.

In example 5, the initial average contact resistance was 4 milliohms as measured by the four-probe method, no short circuit occurred between the electrodes, the resistance remained unchanged after the high temperature and high humidity test, and the shear strength was 6MPa as measured by the push-pull force tester. The result shows that the anisotropic conductive adhesive disclosed by the invention can form effective and reliable connection, is suitable for connecting a chip with an electrode spacing smaller than 50um and a substrate, and is improved in conductivity.

The anisotropic conductive adhesive prepared by the formula and the preparation process can be in a liquid paste shape or a semi-solid film shape. The anisotropic conductive bonding adhesive can be used for a connecting structure body of an electronic element, the connecting structure comprises a miniLED chip and a circuit substrate, conductive electrodes are arranged on the chip, a bonding pad is arranged on the circuit substrate, and the miniLED chip is formed on the circuit substrate by using the anisotropic conductive bonding adhesive.

Example 6

In order to realize the integrated preparation process, the invention provides an integrated preparation device according to the preparation process, the integrated preparation device finishes the whole preparation process in the same reaction chamber fusion chamber, no assembly line type work exists, and the whole preparation process can be seamlessly connected according to the process requirements because the reaction chamber does not need to be replaced, and meanwhile, the preparation device can be customized according to the process requirements in the preparation process.

As shown in fig. 2 and 3, the integrated preparation device specifically comprises an inner operation cavity 1 and an outer environment cavity 2, wherein the inner operation cavity 1 and the outer environment cavity 2 are fixedly connected through a U-shaped frame 3, the inner operation cavity 1 and the outer environment cavity 2 are separated by a partition plate 4 fixedly installed on the top of the U-shaped frame 3 to form two independent cavities, and an air pipe 5 is respectively arranged in the inner operation cavity 1 and the outer environment cavity 2.

In the present invention, the whole operation room is divided into two parts by providing the inner operation chamber 1 and the outer environment chamber 2, wherein the outer environment chamber 2 functions in two aspects, firstly, it is used for shielding the outer environment in the whole preparation process, providing a more stable environment, such as inert gas atmosphere, preventing impurities in the outer environment from affecting the whole process, and providing a better environment for the preparation of the anisotropic conductive adhesive; and secondly, a sub-vacuum environment is provided in the vacuum defoaming process of the preparation process, so that the pressure of the inner operation cavity 1 can be reduced through the sub-vacuum environment, and the process requirement on the whole device is reduced.

The inner operating chamber 1 and the outer environmental chamber 2 are both supplied with an ambient atmosphere and vacuum by means of an air duct 5, so that the device is a factory-like or fully closed structure. Therefore, a discharge port (not shown in the figure) is arranged on the bottom side surface of the inner operation cavity 1 and attached to the bottom surface, and is discharged through the discharge port after the inner operation is completed, it should be noted that the discharge port is not only in a mouth-shaped structure, but also in a discharge structure capable of allowing the discharge of a sticky or block-shaped structure, wherein the discharge port is sealed in a double-layer structure, and the double-layer structure corresponds to the inner operation cavity 1 and the outer environment cavity 2 respectively.

The inner operation cavity 1 comprises a differential base 101 arranged at the bottom of the U-shaped frame 3, a fusion chamber 102 is fixedly arranged on the differential base 101, the differential base 101 is used for providing differential capability for the fusion chamber 102, namely, certain differential operation can be carried out on the entering materials according to actual process requirements, and the fusion chamber 102 is used for fusing all the components together to form a uniformly mixed mixture.

The differentiation in the present embodiment specifically means that the particle components inside the anisotropic conductive adhesive can be arranged under the action of vibration according to the requirements of the process, so as to artificially intervene in the properties of the multidirectional anisotropy, thereby meeting the requirements of the anisotropic property in the process.

Two shielding covers 103 are movably mounted above the fusion chamber 102 in a clamping manner, a rotary shearing and feeding pipe 104 is mounted between the two shielding covers 103 through a bearing, and a plurality of stirring rods 105 which are not uniformly distributed are fixedly mounted on the outer wall of the rotary shearing and feeding pipe 104 positioned in the inner operation cavity 1. The rotary shear feed tube 104 in this embodiment is essentially a stirring device, which is hollow in its own structure, and the hollow structure realizes feeding to the fusion chamber 102, i.e. the stirring device is essentially an aggregate of stirring and feeding.

Rotatory shearing conveying pipe 104 is dispersed the material according to the rotation of rotatory shearing conveying pipe 104 when the pay-off, and the stirring through shear type is so that the material can more abundant mix simultaneously, improves the misce bene degree in this step, provides the basis for subsequent human intervention.

Meanwhile, the tail end of the rotary shearing feeding pipe 104 extends to the bottom of the inner operation cavity 1, a material distributing opening 109 is formed in the side face of the bottom end of the rotary shearing feeding pipe 104, and a material guide plate 110 in an arc shape is fixedly installed inside the material distributing opening 109.

According to the mixing and stirring requirements of the process, the material guide plate 110 partially protrudes out of the material distribution port 109 of the rotary shearing feed pipe 104, so that the shearing force is provided to mix and stir the mixed liquid while the rotary shearing feed pipe 104 rotates. It should be noted that the material guide plate 110 changes the direction of the material conveyed by the rotary shearing feeding pipe 104, and the rotary shearing feeding pipe 104 rotates and simultaneously sends the material out in a centrifugal force manner, so that the material can be dispersed to a certain extent after entering the mixed liquid, and further a better dispersing effect can be achieved in a subsequent process.

According to the amount of the mixed liquid and the layered mixing requirement, the angle of the cambered surface of the guide plate 110 is adjusted through a deflector rod arranged at the bottom, so that the materials can be dispersed to different positions under the action of centrifugal force, and in addition, the guide plate 110 is tangent to the inner wall of the rotary shearing and feeding pipe 104, so that the materials can fly out from the material distributing port 109.

The differential base 101 comprises a hydraulic telescopic support 106 fixedly mounted on the U-shaped frame 3, a chassis 107 is fixedly mounted at the top of the hydraulic telescopic support 106, and the telescopic length of the hydraulic telescopic support 106 is larger than the length of the rotary shearing feeding pipe 104 extending to the inner operation cavity 1.

In order to solve the problem, in the invention, the differentiating base 101 is used as a carrier to drive the fusion chamber 102 to slide up and down, thereby changing the state in the fusion chamber 102, and enabling the fusion chamber to be in a variable process all the time, and improving the mixing effect.

The rotary shear feed tube 104 is driven in the following manner: the rotary shearing feeding pipe 104 sequentially penetrates through the shielding cover 103, the isolation plate 4 and the outer environment cavity 2 from inside to outside, bearings are arranged at the joints of the rotary shearing feeding pipe 104, the isolation plate 4 and the outer environment cavity 2, a driving motor 6 is fixedly installed on the outer environment cavity 2, and the driving motor 6 is connected with the rotary shearing feeding pipe 104 through a bevel gear set 7. Further improve its mixed effect, install a plurality of evenly distributed and mutually independent tremblers 108 in chassis 107. The vibrating reed 108 also functions to provide a vibrating force to differentially settle after being uniformly dispersed.

According to the embodiment, the whole process is divided into two parts in the preparation process of the integrated preparation device, and the raw materials of the product are uniformly distributed by mixing in various ways; secondly, the distribution of the anisotropy is interfered by artificial vibration. Because these two processes are all accomplished in same device is inside to be in the same environment, thereby avoided the semi-manufactured goods to take place the degeneration in the actual operation in-process, make the complete laminating of each process get up in same integrated device, improve the continuity between the process.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A preparation method of anisotropic conductive welding paste comprises tin-bismuth-silver solder balls, an adhesive, high polymer resin, gap particles and an auxiliary aid, wherein the tin-bismuth-silver solder balls are dispersed in the adhesive, and the adhesive comprises epoxy resin and a curing agent, and is characterized by comprising the following steps of:

placing the reactor in a protective gas environment;

2. The method for preparing the anisotropic conductive adhesive according to claim 1, wherein the volume fraction of the tin-bismuth-silver solder ball is 5% to 15%, the particle size is 1 to 30um, and the melting point is 139 to 204 ℃.

3. The method of claim 1, wherein the epoxy resin is a cycloaliphatic epoxy resin, and the curing agent is at least one of a modified cationic curing agent and an anhydride curing agent.

4. The method of claim 1, wherein the polymer resin is at least one of a phenoxy resin and an acrylic resin; the gap particles are at least one of nickel micro powder, silicon micro powder and alumina micro powder, and the particle size of the gap particles is 0.5-5 um; the auxiliary additive is at least one of silane coupling agent, filler, ultraviolet absorbent and antioxidant.

5. An integrated preparation device based on the preparation method of any one of claims 1 to 4, comprising an inner operation chamber (1) and an outer environment chamber (2), wherein the inner operation chamber (1) and the outer environment chamber (2) are fixedly connected through a U-shaped frame (3), the inner operation chamber (1) and the outer environment chamber (2) are separated by a separation plate (4) fixedly arranged on the top of the U-shaped frame (3) to form two independent chambers, and an air pipe (5) is respectively arranged in the inner operation chamber (1) and the outer environment chamber (2);

the inner operation cavity (1) comprises a differential base (101) arranged at the bottom of the U-shaped frame (3), a fusion chamber (102) is fixedly arranged on the differential base (101), two shielding covers (103) are movably arranged above the fusion chamber (102) in a clamping mode, a rotary shearing feeding pipe (104) is arranged between the two shielding covers (103) through a bearing, and a plurality of stirring rods (105) which are not uniformly distributed are fixedly arranged on the outer wall of the rotary shearing feeding pipe (104) positioned in the inner operation cavity (1);

the hydraulic telescopic support is characterized in that the differential base (101) comprises a hydraulic telescopic support (106) fixedly mounted on the U-shaped frame (3), a chassis (107) is fixedly mounted at the top of the hydraulic telescopic support (106), the telescopic variable length of the hydraulic telescopic support (106) is larger than the length of the rotary shearing feeding pipe (104) extending to the inner operation cavity (1), and a plurality of vibrating pieces (108) which are uniformly distributed and are mutually independent are mounted on the chassis (107).

6. The integrated preparation device according to claim 5, wherein the rotary shearing feed pipe (104) passes through the shielding cover (103), the isolation plate (4) and the external environment cavity (2) from inside to outside in sequence, bearings are arranged at the joints of the rotary shearing feed pipe (104) and the isolation plate (4) and the external environment cavity (2), a driving motor (6) is fixedly installed on the external environment cavity (2), and the driving motor (6) is connected with the rotary shearing feed pipe (104) through a bevel gear set (7).

7. The integrated preparation device according to claim 5, wherein the end of the rotary shearing feeding pipe (104) extends to the bottom of the inner operation chamber (1), a material distribution port (109) is arranged on the side surface of the bottom end of the rotary shearing feeding pipe (104), a material guide plate (110) with a cambered surface is fixedly installed inside the material distribution port (109), the angle of the cambered surface of the material guide plate (110) is adjusted by a deflector rod arranged at the bottom, and the material guide plate (110) is tangent to the inner wall of the rotary shearing feeding pipe (104).