Pretreating solution for electroless plating, electroless plating bath and electroless plating process

An electroless plating method comprising:

• subjecting a substrate to a primary plating comprising depositing a primary plated film on a catalyst nucleus;
• after the primary plating, adjusting a surface potential of the primary plated film formed on the substrate so as to be more base than such a most base surface potential that a surface current density of the primary plated film is zero in an electroless plating solution for the secondary plating;
• and
• after the adjusting, subjecting the substrate to a secondary plating comprising electroless plating.

An electroless plating method comprising:

• subjecting a substrate to a primary plating comprising depositing a primary plated film on a catalyst nucleus;
• after the primary plating, adjusting a surface potential of [a] the primary plated film formed on the substrate by using a pretreating solution for electroless plating comprising an alkali solution, a reducing agent and a complexing agent, so as to be more base than such a most base surface potential that a surface current density of the primary plated film is zero in an electroless plating solution for the secondary plating;
• and
• after the adjusting, subjecting the substrate to a secondary plating comprising electroless plating.

An electroless plating method comprising:

• subjecting a substrate to a primary plating comprising depositing a primary plated film on a catalyst nucleus;
• after the primary plating, adjusting a surface potential of [a] the primary plated film formed on the substrate by using a pretreating solution for electroless plating comprising an alkali, a reducing agent, a complexing agent and a solvent for dissolving the alkali, reducing agent and complexing agent, so as to be more base than such a most base surface potential that a surface current density of the primary plated film is zero in an electroless plating solution for the secondary plating;
• and
• after the adjusting, subjecting the substrate to a secondary plating comprising electroless plating.

An electroless plating method comprising:

• subjecting a substrate to a primary plating comprising depositing a primary plated film on a catalyst nucleus;
• after the primary plating, adjusting a surface potential of the primary plated film formed on the substrate by using a pretreating solution for electroless plating comprising an alkali solution, a reducing agent and a complexing agent, so as to be more base than '0.8 V of a saturated calomel electrode as a standard electrode;
• and
• after the adjusting, subjecting the substrate to a secondary plating comprising electroless plating.

An electroless plating method comprising:

• subjecting a substrate to a primary plating comprising depositing a plated film on a catalyst nucleus;
• after the primary plating, adjusting a surface potential of a primary plated film formed on the substrate by using a pretreating solution for electroless plating comprising an alkali, a reducing agent, a complexing agent and a solvent for dissolving the alkali, reducing agent and complexing agent, so as to be more base than -0.8 V of a saturated calomel electrode as a standard electrode;
• and
• after the adjusting, subjecting the substrate to a secondary plating comprising electroless plating.