Forming method of magnetic body, magnetic body, and printed circuit board

Abstract

A method of forming a magnetic body, alternative to a ferrite core, on a printed circuit board is provided. A printed circuit board is set in a mold and injection molding is conducted. The mold comprises a fixed plate, an intermediate plate and a movable plate. A cavity in the intermediate plate is filled with a melted material (i.e., mixture of resin and magnetic filler) supplied via a sprue and a runner. A cavity in the movable plate is also filled with the material supplied to the cavity in the intermediate plate through a hole in the printed circuit board. When a magnetic body for noise control is directly injection molded onto the printed circuit board in such a way, no gap appears between the magnetic body and the printed circuit board. As a result, the magnetic body functions well as desired.

1 - 8 . (CANCELED).  
     
     
         9 . A printed circuit board on which a magnetic body is formed by a method of: 
 preparing a melted material by mixing and melting at least a magnetic filler and a binder including at least one resin,    setting the printed circuit board into a mold, and    performing molding to the printed circuit board using the melted material,    wherein the magnetic body is formed on at least one side of the printed circuit board, and    the magnetic body is formed to cover at least a portion of a circuit pattern on the printed circuit board.    
     
     
         10 . The printed circuit board according to  claim 9 , wherein said magnetic body is formed such that the magnetic body is appressed to said printed circuit board.  
     
     
         11 . The printed circuit board according to  claim 9 , wherein said performing molding step includes an injection molding.  
     
     
         12 . The printed circuit board according to  claim 11 , wherein a gate, used as an inflow opening for supplying said melted material to a cavity of said mold during the injection molding step, is one of a pin gate, a side gate and a submarine gate.  
     
     
         13 . The printed circuit board according to  claim 9 , wherein: 
 the printed circuit board further comprises; 
 at least one through hole,  
 a first surface side, and  
 a second surface side,  
   wherein the through hole forms a passageway for the melted material to communicate with both the first surface side and the second surface side of the printed circuit board, and    the magnetic body is formed on both sides of the printed circuit board.    
     
     
         14 . The printed circuit board according to  claim 9 , wherein said magnetic body is formed from one soft ferrite, hard ferrite, amorphous in Fe, Fe—Si, Fe—Si—Al, Fe—Se—Cr, Fe—Ni, Fe—Cr and Co system, and Fe-based nanocrystal.  
     
     
         15 . The printed circuit board according to  claim 9 , wherein said binder is selected from thermoplastic resin such as EVA (Ethylene-Vinyl acetate copolymer), EVOH (Ethylene-Vinyl alcohol-Copolymer, PVC (PolyVinylChloride), CPE (Chlorinated polyethylene), CA (Cellulose-Acetate), POM (PolyOxyMethylene), PA (PolyAmide), PAR (Polyarylate), TPU (Thermoplastic Polyurethane), TPE (Thermoplastic-Elastomer), LCP (Liquid Crystal Plymer0, PEEK (PolyEtherEtherKetone), PSU (Polysulphone), PES (PolyEtherSulphone), LLDPE (Linear Low Density Polyethylene), PET (PolyEthylene Terephthalate), PC 9PolyCarbonate0, PS 9PolyStyrene0, PPE (PolyPhenyleneEther), PPO (PolyPhenyleneOxide), PPS (PolyPhenyleneSulfide), PBD (PolyButadiene), PBT (PolyButhylene Terephthalate), PP (PolyPropylene), PMMA (PolyMethylMethAcrylate), PMP (Polymethylpentene) and BP (Butyl Phthalate), thermosetting resin such as EP (Epoxy resin), PDAP (Polydiallyl Phthalate), SI (Silicone), PF (Phenol-Formaldehyde), UP (Unsaturated Polyseter0, PI (Polyimide), PUR (Polyurethane0, MF (Melamine-Formaldehyde) and UF (Urea-Formaldehyde), vulcanized rubber such as SBR (Styrene-Butadiene Rubber0, NBR (Nitril-Butadiene Rubber), IIR (Isobutylene-Isoprene Rubber), EPDM (Ethylene-Propylene-Diene Methylene linkage), CSM (CholroSulfonated Polyethylene), AR (Acrylic rubber), FR (Fluorine Rubber), VMQ (Silicone Rubber), ECO (Epichlorhydrin Rubber) and EU (PolyeterUrethane rubber), polyurethane or silicone thermoplastic rubber, liquid rubber and elastomer.  
     
     
         16 . The printed circuit board according to  claim 9 , wherein said circuit pattern is one of a signal line pattern, a power line pattern, a ground line pattern, a transformer circuit patter and a choke coil pattern.  
     
     
         17 . The printed circuit board according to  claim 9 , further comprising: 
 at least one magnetic plate,    wherein the at least one magnetic plate is inserted into the mold containing the printed circuit board prior to molding a melted material, and    the melted material covers at least a portion of the magnetic plate and the circuit pattern of the printed circuit board.    
     
     
         18 . The printed circuit board according to  claim 17 , wherein the magnetic plate is at least one of a sintered ferrite plate and a magnetic metal plate.  
     
     
         19 . A printed circuit board on which a magnetic body is formed by a method of: 
 preparing a melted material by mixing and melting at least a magnetic filler and a binder including at least one resin,    setting the printed circuit board into a mold, and    performing molding to the printed circuit board using the melted material,    wherein the magnetic body is formed on at least one side of the printed circuit board, and    the magnetic body is formed to cover at least a portion of an electronic component on the printed circuit board.    
     
     
         20 . The printed circuit board according to  claim 19 , wherein said magnetic body is formed such that the magnetic body is appressed to said printed circuit board.  
     
     
         21 . The printed circuit board according to  claim 19 , wherein said performing molding step includes an injection molding.  
     
     
         22 . The printed circuit board according to  claim 21 , wherein a gate, used as an inflow opening for supplying said melted material to a cavity of said mold during the injection molding step, is one of a pin gate, a side gate and a submarine gate.  
     
     
         23 . The printed circuit board according to  claim 19 , wherein: 
 the printed circuit board further comprises; 
 at least one through hole,  
 a first surface side, and  
 a second surface side,  
   wherein the through hole forms a passageway for the melted material to communicate with both the first and second surface side of the printed circuit board, and    the magnetic body is formed on both sides of the printed circuit board.    
     
     
         24 . The printed circuit board according to  claim 19 , wherein said magnetic body is formed from one of the soft ferrite, hard ferrite, amorphous in Fe, Fe—Si, Fe—Si—Al, Fe—Si—Cr, Fe—Ni, Fe—Cr and Co system, and Fe-based nanocrystal.  
     
     
         25 . The printed circuit board according to  claim 19 , wherein said binder is selected from thermoplastic resin such as (EVA (Ethylene-Vinyl acetate copolymer), EVOH (Ethylene-Vinyl alcohol-Copolymer), PVC (PolyVinylChloride), CPE (Chlorinated polyethylene), CA (Cellulose-Acetate), Pom (PolyOxyMethylene), PA (PoluAmide), PAR (Polyarylate), TPU (Thermoplastic Polyurethane), TPE (thermoplastic-Elastomer), LCP (Liquid Crystal Polymer), PEEK (PolyEtherEtherKetone), PSU (Polysulphone), PES (PolyEtherSulfone), HDPE (High Density Polyethylene), LDPE (Low Density Polyethylene), LLDPE (Linear Low Density Polyethylene), PPE (PolyPhenyleneEther), PPO (PolyPhenyleneOxide), PPS (PolyPhenyleneSulfide), PBD (PolyButadiene), PBT (PolyButhylene Terephthalate), PP (PolyPropylene), PMMA (PolyMethylMethAcrylate), PMP (Polymethylpentene) and BP (Butyl Phthalate), thermosetting resin such as EP (Epoxy resin), PDAP (Polydiallyl Phthalate), SI (Silicone), PF (Phenol-Formaldehyde), UP (Unsaturated Polyester), PI (Polyimide), PUR (Polyurethane), MF (Melamine-Formaldehyde) and UF (Urea-Formaldehyde), vulcanized rubber such as SBR (Styrene-Butadiene Rubber), NBR (Nitril-Butadiene Rubber), IR (Isoprene Rubber, CR (Chloroprene-Rubber), BR (Butadiene Rubber), IIR (Isobutylene-Isoprene Rubber), EPDM, Ethylene-Propylene-Diene Methylene linkage), CSM (ChloroSulfonated Polyethylene), AR (Acrylic rubber), FR (Fluorine Rubber0, VMQ (Silicone Rubber), ECO (Epichlorhydrin Rubber) and EU (PolyeterUrethane rubber), polyurethane or silicone thermoplastic rubber, liquid rubber and elastomer.  
     
     
         26 . The printed circuit board according to  claim 19 , wherein the electronic component is one of a pin, a resistance, and a condenser.