31results about How to "Avoid expansion and contraction" patented technology

A semiconductor packaging structure and a manufacturing method thereof relate to the technical field of semiconductor packaging. The manufacturing method includes providing a substrate on which a first bonding pad, a second bonding pad, and a plurality of third bonding pads surrounding the periphery of the first bonding pad and the second bonding pad are formed; The three pads are connected by metal bonding to form multiple connection lines; the chip is mounted on the substrate, and the chip is electrically connected to the first pad and the second pad by metal bonding , wherein the connecting wire is located between the bottom of the chip and the substrate; a plastic encapsulation layer is formed on the substrate, and the plastic encapsulation layer covers the chip, the connecting wire, the first pad and the second pad to form a plastic package; through the ball planting process Solder balls are formed on the side of the substrate away from the chip. The manufacturing method of the semiconductor package structure can improve the heat dissipation effect of packaged products.

The invention discloses a method for once molding an inner-layer line of a multilayer flexible circuit board, and technical problems to be solved are improving the production efficiency and the qualified rate of products. The method for once molding the inner-layer line of the multilayer flexible circuit board comprises the following steps of: pasting a dry film in a whole roll, manufacturing an inner-layer line board of a multilayer board of a flexible circuit board, manufacturing an inner-layer line-board layer, manufacturing an inner-layer line-board combined layer, and manufacturing the inner-layer line of the multilayer flexible circuit board. Compared with the prior art, the processing flows of dry-film pasting, exposing, developing, etching, film removing, microetching and pressing are adopted by the invention to manufacture the inner-layer line board, the inner-layer line-board layer, the inner-layer line-board combined layer and the multilayer flexible circuit board, so that problems of height drop generated between a glued area and a non-glue area after inner-layer soft boards are pressed and expansion and shrinkage of the soft boards caused by pressing an inner-layer covering film for many times are avoided, the quality of the multilayer flexible circuit board is improved, the qualified rate reaches more than 92 percent, the process flow is shortened, and the production rate is improved.

The invention discloses a method for manufacturing a multilayer PCB board, which mainly includes: drilling a first through hole on a multilayer PCB board, and metallizing the first through hole to form a first hole wall on the first through hole wall. Conductive layer; perform first backdrilling on the first backdrilling layer along the metallized first through hole to remove part of the first conductive layer located on the first backdrilling layer; on the second backdrilling layer A second back-drilling is performed along the metallized first through hole to remove part of the first conductive layer on the second back-drilled layer. The invention also provides a corresponding multi-layer PCB board. The method of the present invention is by making conductive through-hole on multi-layer PCB board, and removes the part conductive layer of conductive through-hole with the mode of back-drilling, so that the conductive through-hole after back-drilling only connects the conductive layer of lamination, and does not connect with back-drilling. The conductive layer of the drilling layer is disconnected, which realizes the connection between the conductive layers of the stacked layers of the multi-layer PCB board, improves the production efficiency, and reduces the difficulty of alignment.

The invention relates to the technical field of lithium-ion batteries, and specifically provides a lithium-ion battery negative electrode slurry, a preparation method thereof, a negative electrode sheet, and a lithium-ion battery. The negative electrode slurry of the lithium ion battery comprises a negative electrode active material, a conductive agent, a binding agent, a thickener and deionized water, wherein the negative electrode active material is a silicon-based material; the D50 particle diameter of the conductive agent is (0.05~5 ) μm; the binder is styrene-butadiene rubber, and the modulus of elasticity of styrene-butadiene rubber is (1.25-5.0) MPa. In the present invention, the styrene-butadiene rubber with a specific elastic modulus and the conductive agent with a specific D50 particle size make the lithium-ion battery negative electrode slurry exhibit a very high elastic effect when it is coated to form a negative electrode sheet, and can effectively inhibit the expansion of silicon-based materials. Further inhibit the destruction of the SEI film, thereby improving the electrochemical performance of the battery such as high-temperature storage, cycle performance, and high-rate charge and discharge.

The invention discloses a rigid-flex printed circuit board capable of protecting an inner layer windowing area and a production method thereof and belongs to the technical field of rigid-flex printed circuit boards. The rigid-flex printed circuit board is characterized by comprising a flex board and rigid boards arranged on the upper lateral surface and the lower lateral surface of the flex board, and pads or golden fingers are arranged in a windowing area disposed on the flex board. Flex board cover films and pure adhesive films are sequentially arranged between the flex board and the rigid boards arranged on the upper lateral surface and the lower lateral surface of the flex board from inside to outside, cover film windows adaptive to the pads or the golden fingers are arranged on the flex board cover films, pure adhesive film windows adaptive to the windowing area are arranged on the pure adhesive films, and cover film protection layers are arranged between the pure adhesive films and the rigid boards. A plurality of cutting joints are arranged on the rigid boards at intervals along the outer contour of the windowing area. The rigid-flex printed circuit board is reasonable in structure, high in production efficiency and good in use effect and is used for producing printed circuit board products.

The invention discloses a circuit board detection method. The circuit board detection method includes: a screening step, a regeneration step and an exposure step; A qualified circuit board for exposure operation under the first preset value, and an eliminated circuit board that cannot perform exposure operation under the first preset value; A second preset value, and the second preset value is relative to a second film; the exposure step is implemented in an exposure device, and an environment in the exposure device is controlled by an environment control structure The temperature is cooled, so that the Y qualified circuit boards, the first negative, the at least one eliminated circuit board, and the second negative can be maintained during the exposure operation in the exposure equipment. The ambient temperature is below a predetermined temperature.

The invention further provides a high density interconnect (HDI) plate with a mechanic back drilling structure and a manufacturing method thereof. The method comprises that: S1: a first copper foil layer, a first core plate, a second core plate and a sixth copper foil layer are correspondingly subjected to laminating together; S2: the first copper foil layer is subjected to mechanic back drilling processing with the drilling depth reaching a third copper foil layer, and the first copper foil layer, the second copper foil layer and the third copper foil layer are correspondingly connected; S3: the sixth copper foil layer is subjected to the mechanic back drilling processing with the drilling depth reaching a fourth copper foil layer, and the sixth copper foil layer, a fifth copper foil layer and the fourth copper foil layer are correspondingly connected. By adopting a manufacturing way that two core plates are firstly subjected to the laminating one time and then are subjected to the mechanic back drilling processing one time, the production cycle of the HDI plate is greatly shortened, the production cost is reduced, at the same time, the problem of panel expansion caused by multiple times of laminating, laser drillings and abrasive belt grindings is avoided, and the counterpoint accuracy between layers is guaranteed. Compared with the prior art, the HDI plate has the advantages of simple manufacturing process, high production efficiency, low cost and the like.

The invention provides a flexible circuit board manufacturing method. The flexible circuit board manufacturing method at least comprises the following steps that 1, a first circuit board to be bonded and a second circuit board to be bonded are provided, wherein the first circuit board to be bonded and the second circuit board to be bonded respectively comprise a polyimide substrate and a copper line, each polyimide substrate is provided with a plurality of through holes, each copper line is formed on one face of the corresponding substrate, and the copper lines cover the through holes to serve as bonding pads; 2, the bonding pads, needing to be bonded, on the first circuit board to be bonded and the second circuit board to be bonded are stretched, and bonding pad convex points are formed on the to-be-bonded faces of the bonding pads; 3, the first circuit board to be bonded and the second circuit board to be bonded are stacked, so that the bonding pad convex points make contact to form junction points; 4, pulse voltage is exerted on the two ends of the jointed bonding pads so that welding current can be generated, and the junction points are at a high temperature instantaneously and in a molten state, so that the jointed bonding pads are welded in a fusion mode. The bonding pads are welded in the fusion mode in a pulse voltage spot welding mode, the flexible circuit board holes can be communicated and connected, the process is simple and efficient, and meanwhile good economic benefits and social benefits are obtained.