Printed circuit boards (PCBS) have been around since 1936. They are still part of several advanced circuits. The demand for compact sizes and high density printed circuit boards is increasing. This is due to the increasing number of small devices that require small chips. Nowadays, due to the increasing popularity of advanced manufacturing technologies, it is easy to achieve the smallest PCB size. Although PCB manufacturers have experimented with a variety of sizes, materials, and technologies, they also rely on Gerber files to oversee the production of printed circuit boards. What is a Gerber file? How do they add value to any PCB manufacturing process? This article focuses on these and other aspects of the Gerber document, and their importance.
Gerber file is one of the important file formats used in circuit board design. The files were originally developed by GerberSystemsCorp, a subsidiary of GerberScientific. It describes the functions of the board, such as many solder resistance layers, conductor layers, legends, drilling data, etc.
Typically, printed circuit boards are designed in computer-aided design (CAD) systems that utilize manufacturing data to create a two - or three-dimensional design of the PCB. Data needs to be fed into these systems to produce these designs. This sounds easy, because one would think it's a system that automatically generates designs when data is entered. But this is not true, because the user must refer to the guidelines and references mentioned in the Gerber document when entering the data. Gerber documents have been developed to detail the requirements for each stage of product development. These files are used for both PCB manufacturing and PCB assembly processes.
The Gerber file follows the ASCII vector format and provides the following information: configuration parameters, macro and aperture sizes, drawing and flash command codes, XY coordinate positions for drawing and flash commands, a Gerber file for each borehole range and image layer of the board. These files are archived in one file and sent to the printed circuit board manufacturer. Sometimes, printed circuit board manufacturers may receive more than eight standard two-layer PCB files, or even more. They may include the following:
An image of the copper wiring will be included on the bottom of the PCB.
Similarly, there will be two files for solder resistance layer and screen printed images, respectively, applied to the bottom and top of the PCB. There will be documents indicating several boreholes, their location and purpose. Many times, surface mounting and plating through holes are noted in different documents. There will be a detailed outline of the board, describing the machining process to be performed, the internal cuts to be made, etc. In addition, it contains a file called README, which explains the purpose of the above file.
Gerber is a two-dimensional vector image file format. It is the standard format used in printed circuit board industry software to describe printed circuit board images, such as: line layer, solder mask layer, character layer, drill layer and other information. That is, it acts as an intermediate medium for converting graphic data of PCB design into PCB manufacturing data, that is, a CAD-CAM data conversion format standard.
The Gerber format was originally developed by Gerber Systems. The Gerber format is now owned by Ucamco due to the acquisition of Gerber Systems by its predecessor, Barco.
There are two versions of the Gerber format:
Gerber X2's latest file format, as an extension of the RS-274X standard and backward compatible, adds previously missing production data, including: PCB stack structure information, pad and through-hole properties, critical impedance control routing information, and more.
The extended Gerber format, or RS-274X format, is widely used today.
The standard Gerber format, or RS-274D format, has been deprecated and replaced by the RS-274X format.
Attention, RS-274D is obsolete! It has been abandoned! It has been abandoned! Please look for RS-274X format in future Gerber!
One of the applications of the Gerber format is to convert PCB design data from design to production. PCBS are usually designed by circuit board designers using professional electronic design automation (EDA) or computer-aided design (CAD) software, and then output into Gerber format files. Gerber files are sent to the PCB factory and fed into a computer-aided manufacturing CAM system to transform the design information and provide data for each process of PCB production.
The safest way to submit PCB production data to the board factory is to export the Gerber file by yourself, and then submit the Gerber file and board making requirements to the board factory after testing it correctly in the CAM software.
OK, there is a misunderstanding that we often think that the submitted PCB plate making documents will be used by the board factory for direct production, and the Gerber documents will be used directly for the light drawing machine; Excellon drilling files will go directly to the drilling machine; And the IPC-D-356A netsheet will directly drive the flying needle test.
In fact, the board factory will not directly use your Geber file or drilling file for production, the most direct reason is PCB board production, board factory in order to reduce manufacturing costs, the usual practice is to put the small board into a large board processing, in the last process of the manufacturing process and then cut them. Therefore, board factories often assemble PCB data provided by multiple customers into a large standard panel for production in order to make full use of the board and reduce manufacturing costs.
English
Chinese