Wet etched insulator and electronic circuit component

Abstract

The present invention relates to an insulator as an insulating layer in a laminate which can inhibit dusting at the time of use, more particularly an electronic circuit component to which the insulator has been applied, particularly a wireless suspension. The insulator comprises a laminate of one or more insulation unit layers etchable byawet process, the insulator having been subjected to plasma treatment after wet etching. The insulator exists mainly as an insulating layer in a laminate having a layer construction of first inorganic material layer—insulating layer—second inorganic material layer or a layer construction of inorganic material layer—insulating layer, and at least a part of the inorganic material layer has been removed to expose the insulating layer.

1 . An insulator comprising a laminate of one or more insulation unit layers etchable by a wet process, said insulator having been subjected to plasma treatment after wet etching.  
   
   
       2 . The insulator according to  claim 1 , wherein the plasma treatment has been carried out for not less than 0.01 sec and not more than 30 min.  
   
   
       3 . The insulator according to  claim 1 , wherein the plasma treatment has been carried out under the atmospheric pressure.  
   
   
       4 . The insulator according to  claim 1 , wherein the plasma treatment has been carried out under reduced pressure.  
   
   
       5 . The insulator according to  claim 1 , wherein all the insulation unit layers contain an organic material.  
   
   
       6 . The insulator according to  claim 1 , wherein all the insulation unit layers contain an organic material and at least one of the unit layers further contains an inorganic material.  
   
   
       7 . The insulator according to  claim 5 , wherein the organic material is a polyimide resin.  
   
   
       8 . The insulator according to  claim 1 , wherein at least one of the insulation unit layers is formed of a low-expansion polyimide having a coefficient of linear thermal expansion of not more than 30 ppm.  
   
   
       9 . The insulator according to  claim 1 , which comprises a laminate of one or more insulation unit layers etchable by the wet process and has a layer construction of adhesive polyimide—low-expansion polyimide having a coefficient of linear thermal expansion of not more than 30 ppm—adhesive polyimide.  
   
   
       10 . The insulator according to  claim 1 , wherein the wet etching has been carried out with an etching liquid having a pH value of more than 7.0.  
   
   
       11 . The insulator according to  claim 1 , wherein the insulator exists as an insulating layer in a laminate having a layer construction of first inorganic material layer—insulating layer—second inorganic material layer or a layer construction of inorganic material layer—insulating layer and at least a part of the inorganic material layer has been removed to expose the insulating layer.  
   
   
       12 . The insulator according to  claim 11 , wherein all the inorganic material layers are formed of copper or surface treated copper.  
   
   
       13 . The insulator according to  claim 11 , wherein all the inorganic material layers are formed of alloy copper or surface treated alloy copper.  
   
   
       14 . The insulator according to  claim 11 , wherein all the inorganic material layers are formed of stainless steel or surface treated stainless steel.  
   
   
       15 . The insulator according to  claim 11 , wherein one of the inorganic material layers is formed of stainless steel or surface treated stainless steel and the other inorganic material layer is formed of copper or surface treated copper.  
   
   
       16 . The insulator according to  claim 11 , wherein one of the inorganic material layers is formed of stainless steel or surface treated stainless steel and the other inorganic material layer is formed of alloy copper or surface treated alloy copper.  
   
   
       17 . An electronic circuit component comprising the insulator according to  claim 1  applied as an insulating layer.  
   
   
       18 . A suspension for a hard disk drive, comprising the insulator according to  claim 1  applied as an insulating layer.  
   
   
       19 . An insulator comprising a laminate of one or more insulation unit layers etchable by a wet process, said insulator having been heat treated after wet etching.  
   
   
       20 . The insulator according to  claim 19 , wherein the heat treatment is carried out at a temperature of not less than 100° C. and not more than 400° C. for not less than 0.01 sec and not more than 30 min.  
   
   
       21 . The insulator according to  claim 19 , wherein the heat treatment has been carried out under an inert atmosphere.  
   
   
       22 . The insulator according to  claim 19 , wherein the heat treatment has been carried out under a reduced pressure of not less than 10 −2  Torr.  
   
   
       23 . The insulator according to  claim 19 , wherein all the insulation unit layers contain an organic material.  
   
   
       24 . The insulator according to  claim 19 , wherein all the insulation unit layers contain an organic material and at least one of the unit layers further contains an inorganic material.  
   
   
       25 . The insulator according to  claim 23 , wherein the organic material is a polyimide resin.  
   
   
       26 . The insulator according to  claim 19 , wherein at least one of the insulation unit layers is formed of a low-expansion polyimide having a coefficient of linear thermal expansion of not more than 30 ppm.  
   
   
       27 . The insulator according to  claim 19 , which comprises a laminate of one or more insulation unit layers etchable by the wet process and has a layer construction of adhesive polyimide—low-expansion polyimide having a coefficient of linear thermal expansion of not more than 30 ppm—adhesive polyimide.  
   
   
       28 . The insulator according to  claim 19 , wherein the wet etching has been carried out with an etching liquid having a pH value of more than 7.0.  
   
   
       29 . The insulator according to  claim 19 , wherein the insulator exists as an insulating layer in a laminate having a layer construction of first inorganic material layer—insulating layer—second inorganic material layer or a layer construction of inorganic material layer—insulating layer and at least a part of the inorganic material layer has been removed to expose the insulating layer.  
   
   
       30 . The insulator according to  claim 29 , wherein all the inorganic material layers are formed of copper or surface treated copper.  
   
   
       31 . The insulator according to  claim 29 , wherein all the inorganic material layers are formed of alloy copper or surface treated alloy copper.  
   
   
       32 . The insulator according to  claim 29 , wherein all the inorganic material layers are formed of stainless steel or surface treated stainless steel.  
   
   
       33 . The insulator according to  claim 29 , wherein one of the inorganic material layers is formed of stainless steel or surface treated stainless steel and the other inorganic material layer is formed of copper or surface treated copper.  
   
   
       34 . The insulator according to  claim 29 , wherein one of the inorganic material layers is formed of stainless steel or surface treated stainless steel and the other inorganic material layer is formed of alloy copper or surface treated alloy copper.  
   
   
       35 . An electronic circuit component comprising the insulator according to  claim 19  applied as an insulating layer.  
   
   
       36 . A suspension for a hard disk drive, comprising the insulator according to  claim 19  applied as an insulating layer.  
   
   
       37 . An insulator comprising a laminate of one or more insulation unit layers etchable by a wet process, said insulator having been treated with a dehydration catalyst after wet etching.  
   
   
       38 . The insulator according to  claim 37 , wherein the dehydration catalyst is an acid anhydride or an acid anhydride diluted with a solvent.  
   
   
       39 . The insulator according to  claim 37 , wherein the dehydration catalyst is a carbodiimide or a carbodiimide diluted with a solvent.  
   
   
       40 . The insulator according to  claim 37 , wherein the dehydration catalyst is a compound selected from acetic anhydride, tetrafluoroacetic anhydride, dicyclohexylcarbodiimide, carbodiimide resin, 1,5-diazabicyclo[4.3.0]non-5-ene, concentrated sulfuric acid, phosphoryl chloride, and phosphorus trichloride, or the selected compound which has been diluted with a solvent.  
   
   
       41 . The insulator according to  claim 38 , wherein the dehydration catalyst further comprises a tertiary amine and/or pyridine as a reaction accelerator.  
   
   
       42 . The insulator according to  claim 41 , wherein the tertiary amine is triethylamine.  
   
   
       43 . The insulator according to  claim 37 , wherein all the insulation unit layers contain an organic material.  
   
   
       44 . The insulator according to  claim 37 , wherein all the insulation unit layers contain an organic material and at least one of the unit layers further contains an inorganic material.  
   
   
       45 . The insulator according to  claim 43 , wherein the organic material is a polyimide resin.  
   
   
       46 . The insulator according to  claim 37 , wherein at least one of the insulation unit layers is formed of a low-expansion polyimide having a coefficient of linear thermal expansion of not more than 30 ppm.  
   
   
       47 . The insulator according to  claim 37 , which comprises a laminate of one or more insulation unit layers etchable by the wet process and has a layer construction of adhesive polyimide—low-expansion polyimide having a coefficient of linear thermal expansion of not more than 30 ppm—adhesive polyimide.  
   
   
       48 . The insulator according to  claim 37 , wherein the wet etching has been carried out with an etching liquid having a pH value of more than 7.0.  
   
   
       49 . The insulator according to  claim 37 , wherein the insulator exists as an insulating layer in a laminate having a layer construction of first inorganic material layer—insulating layer—second inorganic material layer or a layer construction of inorganic material layer—insulating layer and at least a part of the inorganic material layer has been removed to expose the insulating layer.  
   
   
       50 . The insulator according to  claim 49 , wherein all the inorganic material layers are formed of copper or surface treated copper.  
   
   
       51 . The insulator according to  claim 49 , wherein all the inorganic material layers are formed of alloy copper or surface treated alloy copper.  
   
   
       52 . The insulator according to  claim 49 , wherein all the inorganic material layers are formed of stainless steel or surface treated stainless steel.  
   
   
       53 . The insulator according to  claim 49 , wherein one of the inorganic material layers is formed of stainless steel or surface treated stainless steel and the other inorganic material layer is formed of copper or surface treated copper.  
   
   
       54 . The insulator according to  claim 49 , wherein one of the inorganic material layers is formed of stainless steel or surface treated stainless steel and the other inorganic material layer is formed of alloy copper or surface treated alloy copper.  
   
   
       55 . An electronic circuit component comprising the insulator according to  claim 37  applied as an insulating layer.  
   
   
       56 . A suspension for a hard disk drive, comprising the insulator according to  claim 37  applied as an insulating layer.  
   
   
       57 . A process for producing an electronic component, comprising the steps of: 
 wet etching a laminate of conductive inorganic material layer—insulating layer—conductive inorganic material layer or a laminate of conductive inorganic material layer—insulating layer to pattern the conductive inorganic material layer; and    then performing wet etching to pattern the insulating layer, wherein    the insulating layer in the laminate is wet etchable and has a single-layer structure or a laminate structure of two or more insulation unit layers, and    the patterning of the insulating layer by the wet etching is carried out using a dry film resist.