Keyword: PCB production, PCB design, PCB production process, PCB shape, PCB board
PCB production process have? PCB design for PCB shape is too small, can not meet the requirement of the production process, or a product is composed of a few pieces of PCB, so you need to take a number of small plate together into a big plate area to meet the requirements of production, or to a multiple PCB products used together and facilitate production types. The former is similar to postage stamps board, it can satisfy the PCB production process conditions also facilitate component types, when use separate again, is very convenient. The latter is a product of several sets of PCB board together, such facilitating production, also facilitate to a product's set, clear. Below small make up a simple introduction to introduce PCB production process.
The generation of optical mapping data
PCB production is the basis of film negatives. Early film negatives, need to make a film, reproduction and recycling for photographic reproduction or image. The accuracy of reproduction must be consistent with the required PCB, and consideration should be given to the production process caused by the deviation to compensate. Reproduction can be provided by the customer can also be made by the manufacturer, but the two sides should close cooperation and negotiation, make it can meet user requirements, and can adapt to the production condition. Under the condition of the users with reproduction, manufacturer shall test and approved for reproduction, the user can assess and approved the original or the first piece of PCB products. Production methods have hand-painted reproduction, texture and CAD drawing. Along with the development of computer technology, PCB CAD technology gets great progress, also unceasingly to multilayer PCB production technology level, thin wire, small aperture, high density direction rapidly increase, the original film plate-making technology has been unable to meet the needs of the PCB design, so the light painting technology. Use light painting machine can directly to the CAD design PCB graphic data files into the computer system of light painting machine, control the light painting machine use light directly on the film plot. Then after developing and fixing film negatives. Use light painting technology making PCB film negatives, quick speed, high precision, good quality, but also avoid the textures or in artificial reproduction possible human error, greatly improving the work efficiency, shorten the PCB production cycle. Laser light painting machine, just can be completed in a very short period of time more than in the past for a long time to finish the work, and its fine wire drawing, high-density blank is unmatched by manual operation. According to the different structures of laser light painting machine, can be divided into flat type, inner barrel type (Internal Drum) and outer barrel type (External Drum). Light painting machine use Gerber - RS274 format is the standard data format, and PCB design production industry standard data format. Gerber format name reference since the light painting machine design and manufacture of pioneer - Gerber companies in the United States. Optical mapping data, is the CAD software design of data conversion is called light painting data (mostly Gerber data), modified by CAM system, editing, complete light painting pretreatment (puzzle, mirror, etc.), so as to meet the requirement of PCB production process. Data is then processed into light painting machine, by the light painting machine of Raster image data processor (Raster) into Raster data, the Raster data sent via high power fast compression reduction algorithm to the laser light painting machine, complete the light painting.
Light painting data format
Light painting is based on vector data format type light painting machine developed on the basis of the data format Gerber data, and the data format of vector type light painting machine expanded, and compatible with the HPGL HP plotter format, Autocad DXF, TIFF and other special and general graphics data format. Some developers also for Gerber CAD and CAM data extension.
The following a simple introduction of Gerber data. The official name of the Gerber data for Gerber RS - 274 format. Vector type light painting machine encoder on each symbol, in the Gerber data, has a corresponding D CODE (D - CODE). In this way, light painting machine can control, choose encoder by D code, draw the corresponding graphics. Will be D and D code corresponding symbol shape, size of the list, or get a D clock. The D clock becomes from CAD design, to light painting machine using this data to a bridge of light painting. Users to provide Gerber light painting data at the same time, must provide the corresponding D clock. So, light painting machine can according to the D to determine which symbol should be chosen disc to computer exposure, so as to draw the correct graphic. In an D code table, generally should include D code, each D code corresponding code disc shape, size, and the way the exposure of the encoder.
