The operating speed of electronic devices such as a computer continues to increase.
For this reason, in recent years, as described, for example, in Japanese Laid-open Patent Publication No. 2000-332301, development of a photoelectrical composite substrate is being advanced for achieving communication between LSI or IC chips included in the electronic devices, by using optical signals. In a telecommunication field such as Internet, communication using optical signals is performed as described, for example, in Japanese Laid-open Patent Publication No. 2004-85756.
When a photoelectric composite substrate is manufactured, for example, a drive element which drives an optical element and a package equipped with the optical element are prepared beforehand. The package is then mounted on a printed circuit board with the position of the optical element aligned with the position of an optical waveguide mounted on the printed circuit board. The package is mounted on the printed circuit board via an electrical connector such as a solder ball.
When an electrical connector such as a solder ball has an electrical contact, an electrical signal may be transmitted therethrough. On the other hand, when an optical axis is not at a predetermined position, the connecting part between the optical element and the optical waveguide does not allow an optical signal to be transmitted. Thus, the positional precision demanded for the connecting part between the optical element and the optical waveguide is higher than the positional precision demanded for the electrical connector such as a solder ball. However, when the package equipped with the optical element is mounted on the printed circuit board, connection failure may occur between the optical element and the optical waveguide because of inevitable positional displacement therebetween caused by heat deformation or the like at the time of reflow.
Thus, it is an object of the present application to provide a method of manufacturing a photoelectric composite substrate, the method enabling relative positional precision between the optical element and the optical waveguide to be improved.