What Is Centroid data? Centroid XY files are mainly used to place the surface mount parts on circuit boards. Centroid data is the machine file in ASCII text format that is also called Component Placement, parts centroid or pick & place file having information of component placement. It can also be used in the Programming of AOI machines to inspect circuit boards.
What Is Centroid Data?
Surface mount components are often placed on your PCBs using automated equipment. Our programmers use the Centroid file (also known as an XY file, Insertion, Pick-and-place or Pick-and-place file) to rapidly program these machines.
Most pick and place users will be familiar with the fact that, on most machines, you have the option to teach the board manually, which involves locating each device one by one with an overhead camera, however, that is both extremely slow as well as impossible if the silkscreen is unclear if indeed there is one.
Centroid XY files contain the details of the position and rotation of each reference denominator that are supposed to be mounted on a printed circuit board. The format can vary but in normal practice, centroid data find in the below order Part Number.
How to Centroid Data from Gerber
The XY location of part placement can be in mil, an inch, or mm; it is calculated from the origin of the printed circuit board for the Centroid File. Here’s a breakdown of the Pick and place file formats must contain the information below-
Reference Designator (RefDes)
The reference designator is known as a RefDes, Bill of material, and PCB markup are reflected in this figure. An electrical schematic or printed circuit board is identified by a reference designator that is unambiguous. One or two letters, followed by a number, comprise the reference designator, for example. C1002 and R13 are two reference designators,
Other than that, Designation Letters to use for electrical and electronic assemblies like resistors are referred to by the letter R, capacitors by the letter C, and relays by the letter K.
The X/Y coordinate of the component from printed circuit Board Origin. “LocationX” and “LocationY” allow us to describe the distance between the part and the board origin. It is important to have the part origin centered in the part when using location values. Origin 0,0 of the board can be found in the lower-left corner. From the top of the board, looking down, the origin for the bottom of the board is in the lower-left corner. (0.0000″) is the preferred unit.
On the top, the rotation goes counterclockwise, and on the bottom, it goes clockwise. Both perspectives are from the point of view of the top of the board. From the perspective of looking at the top of the board, the bottom side parts are seen through the board. The rotation is in degrees and can be measured like 0,45,90..as given in CAD File during PCB design.
CAD layer designators do not necessarily refer to the top or bottom of the layer. The part can be at either the top or bottom of the board. Assemblers and PCB fabrication firms often refer to the top as the component side and the bottom as the solder side.
Pick and place file formats Example
Recommended File Format: .csv, .xls and .xlsx.
Inputs to Generate X-Y Centroid data
In Surface Mount technology to generate and extract Component placement files required Gerber data and Bill of Materials. After that, it was generated through the latest software. In CAD software packages have the facility to generate Centroid files but in others no centroid file is available. So many manufacture reverse engineer these manufacturing files to get Centroid files for machine programming.it usually takes hours and wastage of time and production.
We can use a circuit board reverse engineering process to get the data generated. A circuit board reverses engineering (PCB RE, sometimes called “cloning”) is the process of generating fabrication and design data from a physical board that is identical or closely matched to that board. But this data is not necessity malicious or aimed at intellectual property theft.
Best Gerber editor Software
There are several tools out there that let you perform the same task, and they all rely on pattern matching.Following is a description of how to create a Centroid file using different programs
GC-Prevue – The trial version of this software was really hard to use, perhaps because I don’t do CAD work in my day-to-day job. Electronic manufacturing data can be viewed and printed using GC-Prevue, the industry-standard software. GC-Prevue reads all electronic manufacturing outputs that are typically produced by CAD.
GerberGrab – Apparently it was once a commercial effort but is now free and it works somewhat. It is possible to prepare and verify PCB data with GerberGrab for PCs using the numerous tools available in the software. It does read the silkscreen to generate a BOM that can then be matched with one imported by Versatronics GCPrevue (some versions).
FAB3000 – My current favorite not only doesn’t parse text, but it gives references to each component based on your imported component list, and no attempt is made to recognize the text. While GC is not as concise as other programs, the interface looks decent and the software has a number of options you may find helpful if working in other formats.
Unisoft ProntoPLACE – Although it is in some respects very similar to Fab3000, you will notice loading it To program assembly machines, automatically generate part centroid rotation from Gerber data. Unisoft provides shop floor automation software solutions to New Product Development for over 3 decades
Conclusion – Wrapping it up
So, there you have it understand that In order to program their pick-and-place machines and What Is a Centroid data, PC board assembly houses require a centroid file (or x-y file). It doesn’t matter what you call it, but surface mount assembly robots need a magic file in order to determine where the components should be placed and how they should be positioned. The centroid is referred to as such. In order to set up a PCB, you need a centroid file. What is it and what is its importance.
To achieve the same goal, In the manual teaching and entry method is used in early stage but it was slow and very difficult, there is a method buy advanced interweaves I as looked for alternative tools that are used widely.