Catalytic laminate with conductive traces formed during lamination

A method for forming a multi-layer circuit board from a plurality of catalytic laminate layers, each catalytic laminate layer formed from a resin and catalytic particles, each catalytic laminate layer having a resin rich surface having insufficient catalytic particles to support surface electroless copper deposition, and having catalytic particles below a surface exclusion depth with sufficient density to allow electroless deposition, the method comprising:

• forming channels and via apertures in at least one catalytic laminate layer, the channels extending below the surface exclusion depth;
• depositing a layer of electroless copper in the channels and via apertures;
• filling the channels and via apertures of the at least one catalytic laminate layer with a conductive paste;
• positioning the catalytic laminate layers adjacent to each other;
• subjecting the catalytic laminate layers to elevated pressure and temperature;
• where the elevated pressure and temperature are sufficient to laminate the catalytic laminate layers together and melt or sinter the conductive paste in the channels and apertures into conductive traces.

A method for forming a circuit board layer from a catalytic laminate formed from a resin mixed with catalytic particles and infused through a fiber mesh, the catalytic laminate having catalytic particles an exclusion depth below an outer surface, the method comprising:

• forming channels and apertures into the catalytic laminate, the channels having a depth which exceeds the exclusion depth;
• depositing copper into the channels and apertures using an electroless deposition process;
• filling the channels and apertures with a conductive paste containing metal particles;
• heating the conductive metal particles and catalytic laminate to a temperature sufficient for the conductive metal particles to sinter or melt together to form electrically conductive traces.

A method for forming a multi-layer circuit board from a plurality of catalytic laminate layers, each catalytic laminate layer formed from a resin mixed with catalytic particles and a fiber mesh, the catalytic particles of at least one circuit board layer supporting electroless copper deposition only in channels formed below a catalytic particle exclusion depth of the catalytic laminate, the method comprising:

• forming channels and apertures in each catalytic laminate layer;
• electroless plating copper into the channels and apertures of each said catalytic laminate layer;
• filling the channels and apertures with a conductive paste which includes metal particles;
• placing a plurality of circuit board layers stacked together in a lamination press and heating the conductive metal particles and catalytic laminate to a temperature sufficient for the conductive metal particles to melt or sinter together to form electrically conductive traces in the channels and the at least two circuit board layers to bond to each other.