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.

1 . A mold-casting structure, comprising: 
 at least one dishing formed on a surface of a mold-casting body; and    a plurality of micro-protrusions formed on the dishing, and the tops of the plurality of micro-protrusions constitute a plane;    whereby the inferior grounding of the circuitry secured on the mold-casting structure due to the dishing can be avoided.    
   
   
       2 . The mold-casting structure of  claim 1 , which is made of aluminum alloy or plastic.  
   
   
       3 . The mold-casting structure of  claim 1 , wherein the distance between neighboring micro-protrusions is between 0.01 and 5 mm.  
   
   
       4 . The mold-casting structure of  claim 1 , wherein the diameter of the micro-protrusion is between 0.01 and 5 mm.  
   
   
       5 . The mold-casting structure of  claim 1 , which is applied to a microwave telecommunication apparatus.  
   
   
       6 . The mold-casting structure of  claim 1 , which is applied to a low noise block down converter (LNB).  
   
   
       7 . An improved method for grounding of a mold-casting structure, comprising: 
 verifying a location of at least one dishing on the mold-casting structure; and    forming micro-protrusions on the at least one dishing.    
   
   
       8 . The mold-casting structure of  claim 7 , wherein the dishing is verified by a three-dimensional measurement instrument.  
   
   
       9 . The mold-casting structure of  claim 7 , wherein the verification for the location of the dishing comprises the steps of: 
 daubing paint on a surface of the mold-casting structure; and    scraping the surface along a plane, and the location of the remaining paint being deemed the dishing.    
   
   
       10 . The mold-casting structure of  claim 7 , wherein the micro-protrusions are formed on the surface of the dishing by mechanical processing or electric discharge machining.  
   
   
       11 . The mold-casting structure of  claim 7 , wherein the micro-protrusions are formed on the surface of the dishing by a pin hammer.  
   
   
       12 . The mold-casting structure of  claim 7 , wherein the micro-protrusions are molded by a mold with a concave-convex structure matching the micro-protrusions.