"The second plate H1400 is composed of a plateshaped member for example of a thickness of 0.5 to 1 mm, consisting of a ceramic material such as alumina (Al2O3) or a metal such as Al or SUS, and having apertures larger than the external dimensions of the first and second recording element substrates H1100, H1101 adhered to the first plate H1200." . . . .