Mold-casting structure and improvement method for grounding of the same

Abstract

A mold-casting structure comprises at least one dishing and a plurality of micro-protrusions. The dishing(s) formed on the surface of a mold-casting body, the plurality of micro-protrusions sticking out of the surface of the dishing, and the tops of the micro-protrusions constitute on a plane, so that the grounding issue of the circuitry embedded in the mold-casting structure caused by the dishing can be resolved. The dishing can be verified by daubing paint and scrapping thereafter, the location of remaining paint is deemed the dishing. Moreover, a three-dimensional measurement instrument can be employed for more precise measurement. The micro-protrusions can be formed on the dishing by mechanical processing or electric discharge machining (EDM). Alternatively, a mold with a structure matching the micro-protrusions can be formed first, and consequently the micro-protrusions are formed directly by mold-filling, which is more suitable for mass production.

Description

BACKGROUND OF THE INVENTION [0001] (A) Field of the Invention The present invention is related to a mold-casting structure and the relevant electrical grounding method thereof. In view of the superior grounding efficiency of the mold-casting structure of the present invention, EMI (Electromagnetic Interference) can be prevented effectively. [0002] (B) Description of Related Art [0003] The satellite television systems employ a dish antenna to collect satellite signals, and the signals are then reflected to low noise block down converters (LNB) equipped at the focus of the dish antenna for amplifying the signals and reducing its frequency down to around 1 GHz, i.e., the radio signals are transformed to an intermediate frequency. The adjusted signals are transmitted to an indoor television channel selector via a cable to select the signals of a desired channel, and the selected signals are then amplified, modulated, and then converted into video and audio signals for television viewing...

AI Technical Summary

Benefits of technology

[0008] The objective of the present invention is to provide a mold-casting structure with high grounding efficiency, which can resolve the problem of inferior electrical conduction due to dishings occurring on the mold-casting structure after the mold-casting structure was released from the mold, and so as to avoid EMI effectively.

[0009] To achieve the above objective, the present invention discloses a mold-casting structure. The mold-casting structure comprises at least one dishing and a plurality of micro-protrusions. The at least one dishing formed on the surface of a mold-casting body, the plurality of micro-protrusions sticking out of the surface of the dishing, and the tops of the micro-protrusions constitute a plane, so that the grounding issue of a circuitry designed in the mold-casting structure caused by the dishing can be resolved.

Problems solved by technology

As a result, the grounding quality of a printed circuit board established inside the LNB housing 11 will become worse.

The dishings cause errors of the dimensions to the original design, thus the effect of EMI prevention is inferior due to bad grounding quality.

As a result, the time and cost of the process will increase and the reliability will be difficult to control.

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