Knowledge convergence of science and technology in patent inventions

How do scientific knowledge and technological knowledge interact to influence patent inventions? This study combines the "Reliance on Science in Patenting" dataset with the PATSTAT database to investigate focal patents and their paper references and patent references. A temporal investigation shows a growing tendency that patents absorb more knowledge from patents than papers. Additionally, we conduct two sets of analyses, namely, studying the knowledge flow among 35 technology fields and 39 science fields and estimating the impact of cited references on patent impact. The results show that the fields are heterogeneous in absorbing scientific knowledge and technological knowledge. The empirical models indicate that the knowledge depth of both science and technology show an inverted U-shaped relationship with patent impact, while the curve of former is steeper. The knowledge breadth of both science and technology present a Ushaped relationship with patent impact, while the curve of latter is steeper. We also explore the impact of time lags and time spread on citations and estimate their joint effects. Our study provides a new understanding of the convergence of scientific knowledge and technological knowledge to facilitate patent inventions.