| 摘要 |
This invention relates to electronic packaging, and more particularly, to ceramic composites for electronic packaging. Electronic packaging most often refers to an assembly wherein semiconducting silicon chips are attached to a substrate by a conductive pathway and encapsulated by plastic or ceramic materials. Materials having a low dielectric constant (e.g., less than 4.0) are preferred for substrates for electronic packaging in order to reduce dielectric loss at high frequencies. The use of ceramics in electronic packaging applications is well-known. The primary use of ceramic packages are in high performance applications wherein a large number of circuits must be wired on individual ceramic substrates and hermetically sealed. It would be desirable to develop a ceramic that can be fired at the high temperature required for metallization and that would also have a dielectric constant of no greater than 5.0, in order to maintain the propagation velocity of high-speed digital signals in circuits. This invention provides machinable ceramic composites having a low dielectric constant. The composite comprises ceramic bubbles uniformly distributed throughout a ceramic matrix. These composites can be used as ceramic substrates and housings in electronic packaging, and as windows transparent to microwave and millimeter wave radiation. |
