Wiring board, and electronic device with an electronic part mounted on a wiring board, as well as method of mounting an electronic part on a wiring board

Abstract

An electronic device is mounted on a wiring board, which includes: a substrate having through holes, and lands extending on surfaces of the substrate and adjacent to openings of the through holes. Further, at least one coating layer is provided, which coats at least one part of an outer peripheral region of the at least one land, in order to cause that the at least one part is separated from a lead-less solder, thereby preventing any peel of the land from the surface of the substrate.

1 . A wiring board including: 
 a substrate having at least one through hole;    at least one land extending on at least one surface of said substrate, and said at least one land extending adjacent to an opening of said at least one through hole; and    at least one coating layer which coats at least one part of an outer peripheral region of said at least one land.    
   
   
       2 . The wiring board as claimed in  claim 1 , further including: 
 a first conductive film extending on an inner wall of said at least one through hole, and said first conductive film being connected with said at least one land;    at least one circuit wiring extending on said at least one surface of said substrate, and said at least one circuit wiring being connected with a connecting part of an outer peripheral region of said at least one land; and    at least one protection film covering said at least one circuit wiring.    
   
   
       3 . The wiring board as claimed in  claim 2 , wherein said at least one coating layer omnidirectionally coats an entirety of said outer peripheral region of said at least one land.  
   
   
       4 . The wiring board as claimed in  claim 2 , wherein said at least one coating layer coats an entirety of said at least one land.  
   
   
       5 . The wiring board as claimed in  claim 2 , wherein said at least one coating layer coats said connecting part adjacent to said at least one circuit wiring.  
   
   
       6 . The wiring board as claimed in  claim 2 , wherein said at least one coating layer coats an opposite part of said outer peripheral region of said at least one land, and said opposite part is positioned opposite to said connecting part adjacent to said at least one circuit wiring.  
   
   
       7 . The wiring board as claimed in  claim 2 , wherein said at least one coating layer coats both said connecting part adjacent to said at least one circuit wiring and an opposite part of said outer peripheral region of said at least one land, and said opposite part is positioned opposite to said connecting part adjacent to said at least one circuit wiring.  
   
   
       8 . The wiring board as claimed in  claim 2 , wherein said at least one coating layer coats an entirety of said at least one land and said at least one through hole.  
   
   
       9 . The wiring board as claimed in  claim 2 , further including a sub-land region at a boundary between said at least one land and said at least one circuit wiring, and said sub-land region is wider than said at least one circuit wiring and narrower than a horizontal size of said at least one land.  
   
   
       10 . The wiring board as claimed in  claim 1 , wherein said at least one coating layer comprises a material having a thermal stability at a temperature of a melting point of a lead-less solder.  
   
   
       11 . The wiring board as claimed in  claim 10 , wherein said lead-less solder is one selected from the groups consisting of tin-zinc-based solders, tin-silver-based solders, and tin-copper-based solders.  
   
   
       12 . A wiring board including: 
 a substrate having at least one through hole, and said substrate having a first surface and a second surface opposite to said first surface;    a first conductive film extending on an inner wall of said at least one through hole;    at least one first-side circuit wiring extending on said first surface of said substrate;    at least one second-side circuit wiring extending on said second surface of said substrate;    at least one first-side protection film covering said at least first-side circuit wiring on said first surface of said substrate;    at least one second-side protection film covering said at least second-side circuit wiring on said second surface of said substrate;    at least one first-side land extending on said first surface of said substrate, and said at least one first-side land extending adjacent to a first-side opening of said at least one through hole, and said at least one first-side land being connected with said first conductive film and also with said at least one first-side circuit wiring;    at least one second-side land extending on said second surface of said substrate, and said at least one second-side land extending adjacent to a second-side opening of said at least one through hole, and said at least one second-side land being connected with said first conductive film and also with said at least one second-side circuit wiring;    at least one first-side coating layer extending on said first surface of said substrate, and said at least one first-side coating layer coating at least one part of an outer peripheral region of said at least one first-side land; and    at least one second-side coating layer extending on said second surface of said substrate, and said at least one second-side coating layer coating at least one part of an outer peripheral region of said at least one second-side land.    
   
   
       13 . The wiring board as claimed in  claim 12 , wherein said at least one first-side coating layer omnidirectionally coats an entirety of said outer peripheral region of said at least one first-side land, and said at least one second-side coating layer omnidirectionally coats an entirety of said outer peripheral region of said at least one second-side land.  
   
   
       14 . The wiring board as claimed in  claim 12 , wherein said at least one first-side coating layer coats an entirety of said at least one first-side land, and said at least one second-side coating layer coats an entirety of said at least one second-side land.  
   
   
       15 . The wiring board as claimed in  claim 12 , wherein said at least one first-side coating layer coats a first-side connecting part of said at least one first-side land, and said first-side connecting part being adjacent to said at least one first-side circuit wiring, and said at least one second-side coating layer coats a second-side connecting part of said at least one second-side land, and said second-side connecting part being adjacent to said at least one second-side circuit wiring.  
   
   
       16 . The wiring board as claimed in  claim 12 , wherein said at least one first-side coating layer coats a first-side opposite part of said outer peripheral region of said at least one first-side land, and said first-side opposite part is positioned opposite to a first-side connecting part of said at least one first-side land, and said first-side connecting part being adjacent to said at least one first-side circuit wiring, and said at least one second-side coating layer coats a second-side opposite part of said outer peripheral region of said at least one second-side land, and said second-side opposite part is positioned opposite to a second-side connecting part of said at least one second-side land, and said second-side connecting part being adjacent to said at least one second-side circuit wiring.  
   
   
       17 . The wiring board as claimed in  claim 12 , wherein said at least one first-side coating layer coats both a first-side connecting part of said at least one first-side land and a first-side opposite part of said outer peripheral region of said at least one first-side land, and said first-side opposite part is positioned opposite to said first-side connecting part adjacent to said at least one first-side circuit wiring, and said at least one second-side coating layer coats both a second-side connecting part of said at least one second-side land and a second-side opposite part of said outer peripheral region of said at least one second-side land, and said second-side opposite part is positioned opposite to said second-side connecting part adjacent to said at least one second-side circuit wiring.  
   
   
       18 . The wiring board as claimed in  claim 12 , wherein said at least one first-side coating layer coats an entirety of said at least one first-side land and said first-side opening of said at least one through hole, and said at least one second-side coating layer omnidirectionally coats an entirety of said outer peripheral region of said at least one second-side land.  
   
   
       19 . The wiring board as claimed in  claim 12 , wherein said at least one first-side coating layer coats an entirety of said at least one first-side land and said first-side opening of said at least one through hole, and said at least one second-side coating layer coats an entirety of said at least one second-side land.  
   
   
       20 . The wiring board as claimed in  claim 12 , wherein said at least one first-side coating layer coats an entirety of said at least one first-side land and said first-side opening of said at least one through hole, and said at least one second-side coating layer coats a second-side connecting part of said at least one second-side land, and said second-side connecting part being adjacent to said at least one second-side circuit wiring.  
   
   
       21 . The wiring board as claimed in  claim 12 , wherein said at least one first-side coating layer coats an entirety of said at least one first-side land and said first-side opening of said at least one through hole, and said at least one second-side coating layer coats a second-side opposite part of said outer peripheral region of said at least one second-side land, and said second-side opposite part is positioned opposite to a second-side connecting part of said at least one second-side land, and said second-side connecting part being adjacent to said at least one second-side circuit wiring.  
   
   
       22 . The wiring board as claimed in  claim 12 , wherein said at least one first-side coating layer coats an entirety of said at least one first-side land and said first-side opening of said at least one through hole, and said at least one second-side coating layer coats both a second-side connecting part of said at least one second-side land and a second-side opposite part of said outer peripheral region of said at least one second-side land, and said second-side opposite part is positioned opposite to said second-side connecting part adjacent to said at least one second-side circuit wiring.  
   
   
       23 . The wiring board as claimed in  claim 12 , further including a sub-land region at a boundary between said at least one land and said at least one circuit wiring, and said sub-land region is wider than said at least one circuit wiring and narrower than a horizontal size of said at least one land.  
   
   
       24 . The wiring board as claimed in  claim 12 , wherein said at least one coating layer comprises a material having a thermal stability at a temperature of a melting point of a lead-less solder.  
   
   
       25 . The wiring board as claimed in  claim 24 , wherein said lead-less solder is one selected from the groups consisting of tin-zinc-based solders, tin-silver-based solders, and tin-copper-based solders.  
   
   
       26 . An electronic device comprising: 
 a wiring board having at least one through hole; and    an electronic part being mounted on said wiring board, and said electronic part having at least one lead being inserted into said at least one through hole and being bonded to said at least one through hole via a lead-less solder, and    wherein said wiring board includes:    a substrate having said at least one through hole;    at least one land extending on at least one surface of said substrate, and said at least one land extending adjacent to an opening of said at least one through hole; and    at least one coating layer which coats at least one part of an outer peripheral region of said at least one land, so that said at least one part of said outer peripheral region of said at least one land is separated from said lead-less solder.    
   
   
       27 . The electronic device as claimed in  claim 26 , wherein said wiring board further includes: 
 a first conductive film extending on an inner wall of said at least one through hole, and said first conductive film being connected with said at least one land;    at least one circuit wiring extending on said at least one surface of said substrate, and said at least one circuit wiring being connected with a connecting part of said outer peripheral region of said at least one land; and    at least one protection film covering said at least one circuit wiring.    
   
   
       28 . The electronic device as claimed in  claim 27 , wherein said at least one coating layer omnidirectionally coats an entirety of said outer peripheral region of said at least one land, so that said entirety of said outer peripheral region of said at least one land is separated from said lead-less solder.  
   
   
       29 . The electronic device as claimed in  claim 27 , wherein said at least one coating layer coats an entirety of said at least one land, so that said entirety of said at least one land is separated from said lead-less solder.  
   
   
       30 . The electronic device as claimed in  claim 27 , wherein said at least one coating layer coats said connecting part adjacent to said at least one circuit wiring, so that said connecting part is separated from said lead-less solder.  
   
   
       31 . The electronic device as claimed in  claim 27 , wherein said at least one coating layer coats an opposite part of said outer peripheral region of said at least one land, so that said opposite part of said outer peripheral region of said at least one land is separated from said lead-less solder, and said opposite part is positioned opposite to said connecting part adjacent to said at least one circuit wiring.  
   
   
       32 . The electronic device as claimed in  claim 27 , wherein said at least one coating layer coats both said connecting part adjacent to said at least one circuit wiring and an opposite part of said outer peripheral region of said at least one land, so that both said connecting part and said opposite part are separated from said lead-less solder, and said opposite part is positioned opposite to said connecting part adjacent to said at least one circuit wiring.  
   
   
       33 . The electronic device as claimed in  claim 27 , wherein said at least one coating layer coats an entirety of said at least one land and said at least one through hole, so that said lead-less solder is confined within said at least one through hole.  
   
   
       34 . The electronic device as claimed in  claim 27 , wherein said wiring board further includes a sub-land region at a boundary between said at least one land and said at least one circuit wiring, and said sub-land region is wider than said at least one circuit wiring and narrower than a horizontal size of said at least one land.  
   
   
       35 . The electronic device as claimed in  claim 26 , wherein said at least one coating layer comprises a material having a thermal stability at a temperature of a melting point of a lead-less solder.  
   
   
       36 . The electronic device as claimed in  claim 35 , wherein said lead-less solder is one selected from the groups consisting of tin-zinc-based solders, tin-silver-based solders, and tin-copper-based solders.  
   
   
       37 . The electronic device as claimed in  claim 26 , wherein said at least one coating layer is provided on a first surface of said substrate, and said first surface faces to said electronic part, so that said at least one part of said outer peripheral region of said at least one land is separated from said lead-less solder, and 
 wherein a second-side projecting length of said at least one lead from a second surface of said substrate is not greater than one half of a horizontal size of said at least one land on said second surface, where said second-side projecting length is defined to be a length of a projecting part of said at least one lead, which projects from said second surface of said substrate, and said land on said second surface of said substrate is in contact with a flat fillet of said lead-less solder.    
   
   
       38 . The electronic device as claimed in  claim 37 , wherein said second-side projecting length is not greater than zero, and said at least one lead is free of any second-side project part from said second surface of said substrate.  
   
   
       39 . The electronic device as claimed in  claim 26 , wherein at least one spacer is provided between said electronic part and a first surface of said substrate, and said first surface faces to said electronic part, so that said at least one part of said outer peripheral region of said at least one land is separated from said lead-less solder, and 
 wherein a second-side projecting length of said at least one lead from a second surface of said substrate is not greater than one half of a horizontal size of said at least one land on said second surface, where said second-side projecting length is defined to be a length of a projecting part of said at least one lead, which projects from said second surface of said substrate, and said land on said second surface of said substrate is in contact with a flat fillet of said lead-less solder.    
   
   
       40 . The electronic device as claimed in  claim 39 , wherein said second-side projecting length is not greater than zero, and said at least one lead is free of any second-side project part from said second surface of said substrate.  
   
   
       41 . The electronic device as claimed in  claim 26 , wherein at least an adjacent part of a first-side projecting part of said at least one lead from a first surface of said substrate is coated with a coating film having a lower reactivity to said lead-less solder in a melt state than said at least one lead, and said first surface faces to said electronic part, and said adjacent part of said first-side projecting part is adjacent to a first-side opening of said at least one through hole, so that an entirety of said at least one land on said first surface of said substrate is separated from said lead-less solder, and 
 wherein said at least one coating layer is provided on a second surface of said substrate, so that said at least one part of said outer peripheral region of said at least one land on said second surface is separated from said lead-less solder.    
   
   
       42 . The electronic device as claimed in  claim 41 , wherein an entirety of said first-side projecting part of said at least one lead is coated with said coating film.  
   
   
       43 . The electronic device as claimed in  claim 26 , wherein said at least one coating layer is provided on a first surface of said substrate, and said first surface faces to said electronic part, so that said at least one part of said outer peripheral region of said at least one land on said first surface is separated from said lead-less solder, and 
 wherein at least an adjacent part of a second-side projecting part of said at least one lead from a second surface of said substrate is coated with a coating film having a lower reactivity to said lead-less solder in a melt state than said at least one lead, and said adjacent part of said second-side projecting part is adjacent to a second-side opening of said at least one through hole, so that an entirety of said at least one land on said second surface of said substrate is separated from said lead-less solder.    
   
   
       44 . The electronic device as claimed in  claim 41 , wherein an entirety of said second-side projecting part of said at least one lead is coated with said coating film.  
   
   
       45 . An electronic device comprising: 
 a wiring board having at least one through hole; and    an electronic part being mounted on said wiring board, and said electronic part having at least one lead being inserted into said at least one through hole and being bonded to said at least one through hole via a lead-less solder, and    wherein said wiring board includes:    a substrate having said at least one through hole; and    at least one land extending on at least one surface of said substrate, and said at least one land extending adjacent to an opening of said at least one through hole, and    wherein at least one part of an outer peripheral region of said at least one land is separated from said lead-less solder.    
   
   
       46 . The electronic device as claimed in  claim 45 , wherein said wiring board further includes: 
 a first conductive film extending on an inner wall of said at least one through hole, and said first conductive film being connected with said at least one land;    at least one circuit wiring extending on said at least one surface of said substrate, and said at least one circuit wiring being connected with a connecting part of said outer peripheral region of said at least one land; and    at least one protection film covering said at least one circuit wiring.    
   
   
       47 . The electronic device as claimed in  claim 46 , wherein said entirety of said outer peripheral region of said at least one land is separated from said lead-less solder.  
   
   
       48 . The electronic device as claimed in  claim 46 , wherein said entirety of said at least one land is separated from said lead-less solder.  
   
   
       49 . The electronic device as claimed in  claim 46 , wherein said connecting part is separated from said lead-less solder.  
   
   
       50 . The electronic device as claimed in  claim 46 , wherein an opposite part of said outer peripheral region of said at least one land is separated from said lead-less solder, and said opposite part is positioned opposite to said connecting part adjacent to said at least one circuit wiring.  
   
   
       51 . The electronic device as claimed in  claim 46 , wherein both said connecting part and an opposite part of said outer peripheral region of said at least one land are separated from said lead-less solder, and said opposite part is positioned opposite to said connecting part adjacent to said at least one circuit wiring.  
   
   
       52 . The electronic device as claimed in  claim 46 , wherein said lead-less solder is confined within said at least one through hole.  
   
   
       53 - 77 . (canceled)