Anisotropic conductive solder paste and its preparation method and integrated preparation device

Abstract

The invention relates to an anisotropic conductive solder paste, which comprises tin-bismuth-silver solder balls, adhesives, polymer resins, interstitial particles and auxiliary additives; the preparation method comprises the following steps: placing a reactor in a protective gas environment and Add components to the reactor in sequence, then fully mix, then carry out differential settlement, and finally add curing agent and auxiliary agent for vacuum degassing; the preparation device includes an inner operating chamber and an outer environment chamber, the inner operating chamber It includes a differentiation base and a fusion chamber, the fusion chamber is installed with a rotary shear feeding pipe, the differentiation base includes a hydraulic telescopic support, a chassis is fixedly installed on the top of the hydraulic telescopic support, and several distribution boxes are installed on the chassis. Uniform and mutually independent vibrating pieces; the invention disperses low-melting tin-bismuth-silver solder balls in the adhesive to form anisotropic conductive solder, the preparation process is simple, and seamless processing is realized through the integrated preparation device, improving product quality.

Description

Technical field [0001] The present invention relates to an anisotropic conductive welding rubber and its preparation method and integrated preparation device, belonging to the technical field of electronic components. Background technique [0002] As a method of mounting the LED element on the package substrate, the flip process (FC) begins widely. The current connection material is mainly solder paste and conductive adhesive, and it is necessary to apply a certain connection material in the pad position of the substrate to be applied. As the size of the electronic component is getting smaller and smaller, the spacing of the electrodes of the element reaches 200um or less, and the welding paste screen process or the adhesive dot rubber is easily short-circuited, so it can be considered to consider the anisotropy Conductive glue is applied to this fine spacing. [0003] In the small pitch LED (or miniled) package, the solder paste printing process or the adhesive dot rubber proces...

AI Technical Summary

Problems solved by technology

[0003] In the small-pitch LED (or miniLED) package connection, the solder paste printing process or the adhesive dispensing process is used as the connection process, which is not only inefficient, but also has low reliability and cannot be used in large-scale industrial production.

The traditional anisotropic conductive adhesive uses metal to wrap resin to form conductive particles. In actual use, the connection between the component and the substrate is only through the physical contact of the conductive particles after the conductive particles are flattened to achieve electrical conduction. The connection resistance is too large to meet the requirements. Package connection of power devices like LEDs

[0004] Moreover, the preparation of the anisotropic conductive adhesive in the prior art is to directly mix the ingredients in the natural environment, and then simply mix them uniformly, and then directly cure the anisotropic conductive adhesive after mixing uniformly to obtain the anisotropic conductive adhesive, but this preparation method There are technical defects: if the cleanliness of the batching process cannot be guaranteed in the natural environment, it is very easy for impurities in the natural environment to enter, affecting the quality of the final anisotropic conductive adhesive. At the same time, the batching process in a non-protective gas environment is extremely difficult It is easy to cause the oxidation of tiny explosive particles, and the anisotropic conductive adhesive prepared by mixing uniformly has a low degree of mixing between the particles on the micro level, which affects its anisotropic conductivity, and on the macro level because there is no difference , the difference in anisotropy is not obvious, and it is impossible to form a sharp comparison in different directions, and this preparation process cannot meet the customization needs of the process

[0005] In actual preparation, due to the high requirements for the preparation process of anisotropic conductive adhesive, when it is necessary to customize the process requirements, it is often necessary to cooperate with a variety of equipment. However, the existing various equipment are independent of each other. During assembly line production, on the one hand, the production process of anisotropic conductive adhesive will be interrupted, which may cause partial condensation and affect the subsequent quality. On the other hand, the interruption of each step will lead to natural differential settlement or Precipitation, and it cannot be recovered in the subsequent process, which may affect the normal production of anisotropic conductive adhesive

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