Method of manufacturing electronic parts

Abstract

The method of manufacturing electronic parts comprises the steps of preparing a mother board; mounting element parts on the mother board; providing a thermosetting resin on a surface of the mother board surface on which the element parts are mounted; semi-curing the thermosetting resin so as to be in a range of a stage B condition of the thermosetting resin; splitting the mother board with the thermosetting resin into individual electronic parts each having a divided mother board, at least one element part and the thermosetting resin thereon; and heating the individual electronic parts so that the thermosetting resin in the stage B condition melts first and is then cured permanently.

What is claimed is:  
     
         1 . A method of manufacturing electronic parts, the method comprising: 
 semi-curing a thermosetting resin located on the surface of a mother board on which one or more electronic components are located to a stage B condition, at least some of the electronic components being encapsulated in the thermosetting resin;    splitting the mother board into individual circuit boards, at least a plurality of the circuit boards having at least one electronic component encapsulated in the resin and mounted on the circuit board so as to form a plurality of electronic parts; and    heating at least some of the individual electronic parts so that the thermosetting resin is first melted and is then permanently cured.    
     
     
         2 . A method according to    claim 1   , wherein each of the individual circuit boards has at least one electronic component located thereon, the at least one electronic component being encapsulated in the resin.  
     
     
         3 . A method according to    claim 2   , wherein the heating step is applied to each of the electronic parts.  
     
     
         4 . A method according to    claim 3   , wherein, for each of the electronic parts, the heating step is carried out at a temperature and over a time period which causes the thermosetting resin to melt and cover at least a portion of a side surface of the circuit board.  
     
     
         5 . A method according to    claim 4   , wherein the heating step is applied to all of the electronic parts simultaneously.  
     
     
         6 . A method according to    claim 3   , further including the step of providing a sheet on an exposed surface of the resin before the semi-curing step.  
     
     
         7 . A method according to    claim 1   , wherein the heating step is applied to each of the electronic parts.  
     
     
         8 . A method according to    claim 1   , further including the steps of: 
 mounting a plurality of electronic components on the surface of the mother board prior to the semi-curing step; and    providing the thermosetting resin on the surface of the mother board and encapsulating at least some of the electronic components after the mounting step but before the semi-curing step.    
     
     
         9 . A method according to    claim 8   , further including the step of preparing the mother board prior to the mounting step.  
     
     
         10 . A method according to    claim 8   , wherein the thermosetting resin provided on the surface of the mother board is a pellet shape.  
     
     
         11 . A method according to    claim 1   , wherein, for each of the electronic parts, the heating step is carried out at a temperature and over a time period which causes the thermosetting resin to melt and cover at least a portion of a side surface of the circuit board.  
     
     
         12 . A method according to    claim 11   , wherein the heating step is applied to all of the electronic parts simultaneously.  
     
     
         13 . A method according to    claim 1   , further including the step of providing a sheet on an exposed surface of the resin before the semi-curing step.  
     
     
         14 . A method according to    claim 1   , wherein the electronic components are arranged on the mother board in a matrix.  
     
     
         15 . A method according to    claim 1   ,. further comprising the step of separating the individual electronic parts with intervals therebetween after the splitting step and before the heating step.  
     
     
         16 . An electronic part, comprising: 
 a circuit board;    at least one electronic component mounted on a main surface of the circuit board; and    a thermosetting resin located on the surface of the circuit board and encapsulating at least one of the at least one electronic component, the thermosetting resin having a top surface layer which has a density greater then an inner layer thereof.    
     
     
         17 . An electronic part according to    claim 14   , wherein the thermosetting layer covers at least a side portion of the circuit board.  
     
     
         18 . An electronic part according to    claim 13   , wherein the side surface is substantially perpendicular to the main surface of the circuit board.