Average Co-Inventor Count = 10.00
ph-index = 2
The patent ph-index is calculated by counting the number of publications for which an author has been cited by other authors at least that same number of times.
Company Filing History:
1. Hitachi, Ltd. (2 from 42,485 patents)
2. Hitachi Tokyo Electronics Co., Ltd. (2 from 21 patents)
2 patents:
1. 5062771 - Vacuum system with a secondary gas also connected to the roughing pump
2. 4835114 - Method for LPCVD of semiconductors using oil free vacuum pumps