（1） The concept of cam
We have the concept of CAD, but in the use of light painting machine, we must have the concept of cam. Because the technological process and technical level of each factory are different, in order to meet the final requirements of users, it is necessary to make necessary adjustments in the production process to meet the requirements of users in terms of accuracy and other aspects. Therefore, cam is an essential process of light drawing production center. All the technological requirements mentioned above should be prepared before light painting. For example, mirror image, solder mask expansion, process line, process frame, line width adjustment, center hole, contour line and other issues should be completed in the cam process.
（2） The process of cam
1. Correction of pad size, combining D code;
2. Correction of line width, combining D code;
3. Inspection of minimum spacing; Between pads, between pads and lines, between lines;
4. Check the size of the aperture and assemble it;
5. Inspection of minimum line width;
6. The expansion parameters of resistance welding are determined;
7. Mirror image;
8. Add a variety of process lines, process frame;
9. Line width correction is carried out to correct side etching;
10. A central hole is formed;
11. Add contour corner line;
12. Add positioning hole;
13. Make up, rotate, mirror;
15. Graphics overlay processing, tangent processing;
16. Add user trademark;
（3） Organization of cam process
Because there are many kinds of popular CAD software in the market, the management of CAD process must start from the organization first. A good organization will get twice the result with half the effort. Since Gerber data format has become the standard of light painting industry, Gerber data should be taken as the processing object in the whole light painting process. If CAD data is used as an object, the following problems will arise.
1. There are too many kinds of CAD software. If all kinds of process requirements are to be completed in CAD software, every operator is required to master the operation of each kind of CAD software. This will require a long training period, so that the operator can become a skilled worker and meet the actual production requirements. This is not cost-effective in terms of time and economy.
2. Due to the variety of process requirements, some requirements can not be realized for some CAD software. Because CAD software is used for design, and does not consider the special requirements in the process, it can not meet all the requirements. CAM software is specially used for process processing, and it is the best to do these jobs.
3. CAM software has powerful functions, but it can only operate Gerber parts, not CAD files.
4. If CAD is used for process treatment, each operator is required to be equipped with all CAD software, and each CAD software has different process requirements. This will cause unnecessary confusion in management.
To sum up, cam organization should be the following structure, especially for large and medium-sized enterprises:
a. Gerber data is taken as the processing object in all process processing.
b. Each operator must master the skills of converting CAD data into Gerber data.
c. Each operator must master one or more operation methods of CAM software.
d. Make unified process specification for Gerber data file.
e. Cam process can be relatively concentrated by several operators for easy management.
Reasonable organization will greatly improve the management efficiency, production efficiency, and effectively reduce the error rate, so as to achieve the effect of improving product quality.
（4） CAM software
Now the common cam software is as follows:
PC gerberd is popular earlier in China and has been widely used, especially in the north. Due to its limited functions, it can not meet the increasingly diverse requirements, and has been phased out in recent years.
Its functions are as follows:
(1) It can operate 32 files at the same time.
(2) Each file can be operated independently, opened and closed.
(3) It can accept all kinds of Gerber data format (basic format): relative coordinate, absolute coordinate, metric system, English system, zero system before and zero system after
(4) You can spell multiple gerbers into one file
(5) You can do various editing operations: add, delete, modify.
(6) You can operate on the following objects: flash, trace, arc, circle, vertex, poly, text
(7) It can perform window operation and group operation
(8) You can change the D code
(9) There are nine forms of D code
* round garden
* rect moment
* target type
* thermal heat sink
* donut ring
* oblong elliptic
(10) Data can be measured.
(11) You can change units.
(12) Can rotate, mirror, copy and other operations
(13) You can fill in contours
(14) It can accept 1000 D codes
The defects are as follows
(1) Only D code table in its own format can be received
(2) Slow operation
(3) The editing function is not strong
2、View 2001（Ver 3.04）
The software has powerful function and fast response speed, which is popular in the south. In addition to the functions of pcgerber, it also has the following features:
(1) Powerful editing function:
a. You can lock an element;
b. You can turn off pad or trace independently;
c. Trace can be cut off;
d. The pad can be selected in a separate color to distinguish it from the line.
(2) When displaying, it is easy to zoom in and out; Click the left mouse button to zoom in and the right mouse button to zoom out.
(3) Accept extended Gerber format (including D code)
(4) Up to 100 files can be operated simultaneously.
(5) It can accept the D code table generated by the following CAD files:
Lavenir Mentor optrotechPADS Cadence
Interactive P-CAD pRotelZuken OrCAD
CadStar Eagle TangoEE-Designer
(6) You can convert a drill file (txt) to a Gerber file.
(7) Gerber can be generated into a drilling file (txt)
(8) HPGL format file can be read and converted to Gerber file.
(9) The extended Gerber can be decomposed into basic Gerber and D code table.
(10) There are 15 kinds of D code
(11) 9990 D codes are acceptable
(12) Dmpl files can be converted to Gerber files.
3. ECAM: it has powerful functions, but its application is small due to its high price.
4. Gccam: it is the most powerful CAM software among the popular software in China.
Its outstanding point is that it has the concept of negative D code, breaking through the traditional limitations.