Patent ID: 7839647

Claim:
An insulating film, comprising: a first polymer layer; a second polymer layer; and an electromagnetic shielding layer sandwiched between the first polymer layer and the second polymer layer; the electromagnetic shielding layer comprising a plurality of carbon nanotube films stacked one on another, the carbon nanotube films being substantially parallel to the first and second polymer layers, each of the carbon nanotube films comprising a plurality of carbon nanotubes which are connected end to end and substantially parallel to each other; wherein the electromagnetic shielding layer includes m layers of the carbon nanotube films, m represents a natural number greater than two, the carbon nanotubes in the nth layer of the m layers of the carbon nanotube films are oriented an angle of (n−1)*θ relative to the carbon nanotubes in the first layer of the carbon nanotube films which is proximate to the second polymer layer, n represents a natural number between 2 to m, θ represents an angle between 0 to 90 degrees.