Composite layer circuit element

An electronic device including a composite layer circuit element, comprising:

• a first dielectric layer;
• a first conductive structure, penetrating a portion of the first dielectric layer;
• a first circuit layer, disposed on the first dielectric layer;
• a second dielectric layer, disposed on the first circuit layer;
• and
• a second conductive structure, disposed on the second dielectric layer and electrically connected to the first conductive structure through the first circuit layer,
• wherein the second conductive structure contacts the first circuit layer, and the second conductive structure does not contact the first conductive structure,
• wherein a thickness of the first dielectric layer is greater than a thickness of the second dielectric layer in a cross section view, and a ratio of the thickness of the first dielectric layer to the thickness of the second dielectric layer is between 1.5 and 5,
• wherein the thickness of the first dielectric layer is between 5 micrometers and 25 micrometers, and the thickness of the second dielectric layer is between 5 micrometers and 25 micrometers,
• wherein a coefficient of thermal expansion of the first dielectric layer and the second dielectric layer is between 15 ppm/° C. and 65 ppm/° C.