Metal Stamping System For Manufacturing High Tolerance
System and process for metal stamping parts having tolerances below 1000 nanometers. The inventive system and process is particularly suited for producing optoelectronic parts. The system includes a metal stamping press and one or a progression of metal stamping stations for supporting a punch and die.
The metal stamping stations are designed to maintain substantial alignment of the punch and die with minimal moving components. The metal stamping station includes a shaft for rigidly guiding the punch to the die. The metal stamping press is capable of providing the punch with the necessary force to perform the metal stamping operations. The system includes an interface system for interfacing the force of the press with the punch, while simultaneously structurally decoupling the press from the punch. The system also includes a locating sub-plate, for locating the metal stamping station in alignment relative to each other, and means for in-line machine stock material before entry into the metal stamping stations.
Precision parts are required in many applications, such as optical fiber based communication. Optical fiber based communication channels are the system of choice in many defense and commercial applications because of their high performance andsmall size. Particularly, fiber optics have 'proved-in' in long distance applications, such as city-to-city and continent-to-continent communication spans, because of the lower cost of electrical-to-optical-to-electrical (E-O-E) conversion components,fiber amplifiers, and fiber cables relative to pure electrical systems using coaxial copper cable that do not requiring E-O-E. These long haul fiber systems can have hundreds of kilometers of fiber between terminals.
Shorter distance systems typically have only a few tens of kilometers of fiber between terminals, and very short reach (VSR) systems have only a few tens of meters of fiber between terminals. Although fiber links for telecom and datacom inmetro, access and premise areas are short as compared to long haul links, there are a great many of them. The number of components required in the deployment of fiber for these types of applications is large. In these short systems, fiber optics'prove-in' is very sensitive to the cost of E-O-E terminal conversion devices and supporting circuitry, as well as any passive and active optoelectronic devices and equipment linked between terminal ends. Consequently, for optoelectronic active andpassive components, sub-assemblies and assemblies to 'prove-in' in short distance and VSR systems, their average sell prices must be lowered. Lowering of the average sell prices will help stimulate the unit volume necessary to justify investment in highspeed manufacturing technologies.
A significant element of the cost of both active and passive fiber components and connectorized cable is the fiber connector itself. Precision ferrules and associated means for aligning them (e.g., precision split sleeve for single fiberconnection, precision ground pins for multi-fiber connections) dominate the cost of current fiber connectors. The alignment components are normally required to align fibers to active and passive devices, as well as to align two fibers for demountableconnection. Precision alignment of two polished fiber ends is needed to ensure that overall optical loss in a fiber link is equal or less than the specified optical connector loss budget for a system. For single-mode telecommunication-grade fiber, thistypically corresponds to connector fiber alignment tolerances that are less than 1000 nm. Current connectors have not changed in basic design for more than 20 years, and it is generally accepted that they cost too much and are too difficult to assemble. The cost of manufacturing precision fiber connectors must decrease if fiber optic is to be the communication media of choice for short haul and VSR applications.
Connectors, in both parallel fiber and single fiber links, operating at multi-gigabit rates must be assembled with subcomponents fabricated with sub micron precision. As if producing parts with such precision levels were not challenging enough,for the resulting end product to be economical it must be done in a fully automated, very high-speed process.
It is therefore desirable to have a manufacturing technology capable of producing parts for optoelectronic applications and other applications with tolerances within 1,000 nanometers and capable of running at very high speeds.
The present invention is directed to a metal stamping system and process for producing parts having tolerances below 1000 nm. The invention is particularly suited for producing optoelectronic parts, including, but not limited to, components,assemblies and subassemblies, and passive and active components. The system includes one or a progression of metal stamping stations for supporting a punch and die. The metal stamping stations include a novel structure for guiding the punch in substantialalignment with the die with tight tolerances. The system includes a press for providing the metal stamping stations with the necessary force to perform the particular metal stamping operation.
In one aspect of the present invention, the system is designed to minimize the number of moving components involved in the support structure in guiding the punch to the die. In one embodiment, the metal stamping station includes no moving component inthe support structure in guiding the punch to the die. The metal stamping station includes a stationary punch holder structure having a shaft sized and shaped to receive the punch with tight tolerances. The punch is guided to the die by sliding through theshaft.
In another aspect of the present invention, the system includes a locating sub-plate having indexing features for precisely aligning the progression of metal stamping stations relative to each other. The locating sub-plate and its indexing featureshave exacting tolerances and sub-micron surface finishes.