Plate material cutting method, printed circuit board, and electronic device

Abstract

According to one embodiment, a plate material cutting method prepares a plate material including a joining member that joins a main body portion to a throw-out portion, sets the plate material on a die including an opening section, and pushes a punch against the joining member. The punch includes a first end portion corresponding to a first end of the joining member which is connected to the main body portion. The punch also includes a second end portion corresponding to a second end of the joining member which is connected to the throw-out portion. A gap smaller than thickness of the plate material is defined between the first end portion of the punch and an inner surface of the opening section. A gap larger than the thickness of the plate material is defined between the second end portion of the punch and the inner surface of the opening section.

1 . A plate material cutting method comprising: 
 preparing a plate material including a main body portion, a throw-out portion and a joining member that joins the main body portion to the throw-out portion;    setting the plate material on a die including an opening section such that the joining member is opposed to the opening section; and    pushing a punch opposing the opening section against the joining member, the punch including a first end portion corresponding to a first end of the joining member which is connected to the main body portion, a gap smaller than thickness of the plate material being defined between the first end portion of the punch and an inner surface of the opening section, the punch also including a second end portion corresponding to a second end of the joining member which is connected to the throw-out portion, a gap larger than the thickness of the plate material being defined between the second end portion of the punch and the inner surface of the opening section.    
     
     
         2 . The plate material cutting method according to  claim 1 , wherein the punch is cylindrical, and the opening section of the die is ellipse having a long axis extending in a direction from the first end portion to the second end portion.  
     
     
         3 . The plate material cutting method according to  claim 1 , wherein the inner surface of the opening section includes a first inner surface portion corresponding to the first end portion of the punch and a second inner surface portion corresponding to the second end portion of the punch, and 
 the second inner surface portion is located under a boundary between the throw-out portion and the joining member when the plate material is set on the die.    
     
     
         4 . The plate material cutting method according to  claim 3 , wherein a boundary between the main body portion and the joining member is located between the first end portion of the punch and the first inner surface portion of the opening section when the plate material is set on the die.  
     
     
         5 . The plate material cutting method according to  claim 4 , wherein the punch is cylindrical, and the opening section of the die is ellipse having a long axis extending in a direction from the first end portion to the second end portion.  
     
     
         6 . The plate material cutting method according to  claim 4 , wherein the opening section of the die extends in a direction in which the punch is inserted, and has a depth greater than a longitudinal dimension of the joining member.  
     
     
         7 . The plate material cutting method according to  claim 6 , wherein the die includes an attachment surface on which the plate material is placed, and 
 the attachment surface is perpendicular to the first and second inner surface portions of the opening section at an opening edge of the opening section.    
     
     
         8 . A printed circuit board comprising: 
 a main body portion prepared from a plate material by use of a punch and a die including an opening section corresponding to the punch, the plate material including the main body portion, a throw-out portion and a joining member that joins the main body portion to the throw-out portion; and    a circuit component mounted on the main body portion,    wherein the punch includes a first end portion and a second end portion,    when the plate material is set on the die, the first end portion of the punch corresponds to a first end of the joining member which is connected to the main body portion, the second end portion of the punch corresponds to a second end of the joining member which is connected to the throw-out portion, a gap smaller than thickness of the plate material is defined between the first end portion of the punch and an inner surface of the opening section, and a gap larger than the thickness of the plate material is defined between the second end portion of the punch and the inner surface of the opening section.    
     
     
         9 . The printed circuit board according to  claim 8 , wherein the punch is cylindrical, and the opening section of the die is ellipse having a long axis extending in a direction from the first end portion to the second end portion.  
     
     
         10 . The printed circuit board according to  claim 8 , wherein the inner surface of the opening section includes a first inner surface portion corresponding to the first end portion of the punch and a second inner surface portion corresponding to the second end portion of the punch, and 
 the second inner surface portion is to be located under a boundary between the throw-out portion and the joining member.    
     
     
         11 . The printed circuit board according to  claim 10 , wherein a boundary between the main body portion and the joining member is to be located between the first end portion of the punch and the first inner surface portion of the opening section.  
     
     
         12 . An electronic device comprising: 
 a casing; and    a printed circuit board received in the casing, the printed circuit board including a main body portion and a circuit component mounted on the main body portion,    wherein the main body portion is prepared from a plate material by use of a punch and a die including an opening section corresponding to the punch, the plate material includes the main body portion, a throw-out portion and a joining member that joins the main body portion to the throw-out portion, the punch includes a first end portion and a second end portion, when the plate material is set on the die, the first end portion of the punch corresponds to a first end of the joining member which is connected to the main body portion, and the second end portion of the punch corresponds to a second end of the joining member which is connected to the throw-out portion, a gap smaller than thickness of the plate material is defined between the first end portion of the punch and an inner surface of the opening section, a gap larger than the thickness of the plate material is defined between the second end portion of the punch and the inner surface of the opening section.    
     
     
         13 . The electronic device according to  claim 12 , wherein the punch is cylindrical, and the opening section of the die is ellipse having a long axis extending in a direction from the first end portion to the second end portion.  
     
     
         14 . The electronic device according to  claim 12 , wherein the inner surface of the opening section includes a first inner surface portion corresponding to the first end portion of the punch and a second inner surface portion corresponding to the second end portion of the punch, and 
 the second inner surface portion is to be located under a boundary between the throw-out portion and the joining member.    
     
     
         15 . The electronic device according to  claim 14 , wherein a boundary between the main body portion and the joining member is to be located between the first end portion of the punch and the first inner surface portion of the opening section.