A copper surface object analysis method based on CAM

Abstract

This invention discloses a CAM-based copper surface object analysis method, comprising the steps of importing an image graphic description file and, based on the type information of each object in the image graphic description file, analyzing and determining whether polygonal objects contain risk information. Through this approach, the CAM-based copper surface object analysis method of the present invention ensures manufacturing yield and management efficiency at the micro level. At the macro level, the standardized analysis system and method integrate upstream and downstream processes, accelerate industrial upgrading, and pave the way for fully automated and intelligent PCB manufacturing, connecting the entire industry chain.

Description

Technical Field

[0001] The present invention relates to the technical field of PCB manufacturing, and in particular to a copper surface object analysis method based on CAM. Background Art

[0002] CAM defines five major types of features: 1. Line, 2. Arc, 3. Pad, 4. Text, and 5. Surface. Broadly speaking, all objects on a circuit board are copper. However, computer-aided manufacturing (CAM) has redefined the concept of copper surface.

[0003] The description of copper surface objects in CAD software is as follows: It is a polygonal outline described by multiple points, and then filled into a surface.

[0004] Reasons for copper-clad objects

[0005] Generally speaking, we can intuitively understand that within a circuit, the three objects—a straight line, an arc, and a pad—ideally describe the circuit. String objects are merely used to indicate text on the circuit board and don't directly affect the circuit. However, this alone isn't enough to complete manufacturing; it requires the addition of a large copper surface.

[0006] The impact of copper-surfaced objects on manufacturing:

[0007] 1. If the area occupied by metal copper is not large enough during the manufacturing of the circuit board, it will cause the board to warp, bend, and be easily deformed during pressing.

[0008] 2. The metal contact surface area is increased to conduct and dissipate heat.

[0009] 3. There are special copper surface requirements for impedance, high frequency, ground electric signals, etc., which involve shielding signals, controlling impedance, etc.

[0010] Scenarios and methods for copper-surfaced objects

[0011] In the early years, the Western PCB industry, due to commercial interests, deliberately did not enforce mandatory standards for file formats, and let the downstream manufacturing end bear the consequences of these chaos, taking advantage of the differences in file formats to profit from them. This barrier within the same industry hindered industrial upgrading.

[0012] The discrepancies in software language descriptions for copper surface objects are a prominent example of a problem plaguing domestic manufacturers. Copper surface objects are typically semi-automatically generated in CAD layout software. However, various CAD software packages on the market differ in their definitions of copper surface objects, leading to various parsing errors when the data is ultimately transferred to the manufacturing CAM software, resulting in costs borne by the board manufacturer.

[0013] This shows that copper-surface objects have a significant impact on manufacturing yield. In the past, the industry's analysis of copper-surface objects relied on engineers' experience and simultaneous analysis and inspection of four other objects, which was inefficient. The industry urgently needs professional and systematic analysis algorithms for copper-surface objects. Summary of the Invention

[0014] The main technical problem solved by the present invention is to provide a copper surface object analysis method based on CAM, which has the advantages of high reliability and high accuracy, and has broad market prospects in the application and popularization of PCB manufacturing.

[0015] In order to solve the above technical problems, a technical solution adopted by the present invention is:

[0016] A method for analyzing copper surface objects based on CAM is provided, the steps of which include:

[0017] (1) Obtain or import the image graphic description file of each layer of PCB circuit board;

[0018] (2) According to the type information of each object in the image graphic description file, polygonal objects with polygonal attributes are screened out from all objects on the circuit board;

[0019] (3) Analyze and determine whether polygonal objects contain risk information;

[0020] (3.1) Determine and analyze the current size information of the polygonal object, compare the current size information with the pre-set size threshold, and generate a list of undersized information and report it;

[0021] (3.2) Analyze and determine whether the description of polygons in polygonal objects is correct, and generate a list of conflicting information;

[0022] (3.3) Analyze and determine whether polygonal objects have too short edges, and generate a too short edge table;

[0023] (3.4) Analyze and determine whether the contour lines of polygonal objects have self-intersecting edges, and generate a self-intersecting edge object table;

[0024] (4) Obtain the risk information in step (3) and generate a copper surface object risk table.

[0025] In a preferred embodiment of the present invention, the image graphic description file includes but is not limited to a .gerber file, a .excellon file, a .ipc file, and an odb++ file.

[0026] In a preferred embodiment of the present invention, the polygonal object includes a Surface object and a Symbol object, wherein:

[0027] Surface object: refers to a copper surface object. When an object is detected as a copper surface object, it is directly judged to be the object for analysis in step 3;

[0028] Symbol object: refers to a custom tray object. When an object is detected as a custom tray object, the symbol description information of the object is obtained and tested to see whether it contains surface attribute information. If it does, the object is judged to perform analysis in step 3.

[0029] In a preferred embodiment of the present invention, the current size information of the polygonal object includes width information and height information, and the size threshold includes a width threshold and a height threshold.

[0030] In a preferred embodiment of the present invention, the step of determining whether the description of the polygon in the polygonal object is correct includes:

[0031] (3.2.1) Classify each polygonal object into a solid object with positive polarity and a hole with negative polarity based on its polarity;

[0032] (3.2.2) Obtain the polygonal outline of each entity and hole, and determine whether the polygonal outline of the entity intersects the polygonal outline of the hole;

[0033] (3.2.2.1) If the hole outline is located within the solid body outline and there is no overlap between the solid body outlines, that is, the hole and the solid body are intersecting and the spacing is greater than 0, then the description of the shell and hole group is normal;

[0034] (3.2.2.2) If the outlines of the hole and the solid do not intersect, or if the outlines of the solid intersect or overlap, then the description of the group of solids and the hole is considered inconsistent.

[0035] In a preferred embodiment of the present invention, the step of determining whether a polygonal object has an excessively short side includes:

[0036] (3.3.1) Obtain the coordinates of the endpoints of the contour lines of each polygonal object in the image graphic description file;

[0037] (3.3.2) Based on the coordinates of the contour endpoints, calculate the length of each polygon edge and compare the edge length with the preset length threshold. If the edge length is less than the length threshold, the edge is judged to be too short.

[0038] In a preferred embodiment of the present invention, the step of analyzing and determining whether the contour line of the polygonal object has a self-intersecting edge includes obtaining the coordinates of the endpoints of the contour lines constituting the polygonal object in the image graphic description file, and connecting two adjacent endpoints to form a line. If the two lines intersect and the intersection point is not the endpoint of the line, it is determined that a self-intersecting edge exists.

[0039] The beneficial effects of the present invention are: at the micro level, it ensures the yield rate and management efficiency of the manufacturing end; at the macro level, it utilizes the improved analysis system and method to standardize and integrate the upstream and downstream, accelerate industrial upgrading, and pave the way for fully automatic and fully intelligent PCB manufacturing to open up the entire industry chain. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0041] Figure 1 This is a schematic diagram of the contrastive structure of holes in a copper surface object in a preferred embodiment of a copper surface object analysis method based on CAM of the present invention;

[0042] Figure 2 This is a schematic diagram of a physical contradiction comparison structure of a preferred embodiment of a copper surface object analysis method based on CAM of the present invention;

[0043] Figure 3 It is a structural schematic diagram of an object with self-intersecting edges in a preferred embodiment of a CAM-based copper surface object analysis method of the present invention. DETAILED DESCRIPTION

[0044] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] See also Figure 1-3 , embodiments of the present invention include:

[0046] A copper surface object analysis method based on CAM, comprising the following steps:

[0047] Step 1: Obtain or import the image graphic description file of each layer of the PCB circuit board; the image graphic description file includes but is not limited to ASCII-based .gerber (.gbr) files, .excellon files, Ipc2581 (.ipc) files, odb++ files, etc.

[0048] Step 2: The CAM software calls the corresponding algorithm (or program) to first filter out objects with polygonal (surface) properties from all objects on the circuit board layer based on the type information of each object. These objects are generally called polygonal objects (polygon means that the object is composed of objects with surface properties). Polygonal objects are mainly divided into the following two categories.

[0049] 1) Surface objects: These are copper-surface objects. These objects are typically described directly by polygons, so they possess polygonal (surface) properties. When an object is detected as a copper-surface object, it is immediately identified and analyzed.

[0050] 2) Symbol object: This refers to a custom tray object. Custom tray objects can be described using only a center point (and its coordinates) or a combination of a center point and a polygon. Therefore, if a Symbol object's attributes include a polygon description, the Symbol object also requires analysis in step 3.

[0051] When an object is detected as a pad, the symbol description of the object is obtained and checked to see if it contains surface attribute information. If so, the object is considered to be involved in the next step of analysis.

[0052] Step 3: Determine and analyze the current size information of the polygonal object (the size information mainly includes width information and height information), and compare the current size information with the pre-set size thresholds (mainly including width threshold and height threshold); when both the width and height are smaller than the size threshold, obtain the current size information that does not meet the size threshold and the corresponding object information, and generate a list of undersized size information (1) and report it.

[0053] Among them, the objects in the undersized information list (1) include:

[0054] (1-1) Small Polygon object: A polygon object that is too small in a copper surface object.

[0055] (1-2) Small Polygon in Symbol object: A polygon object that is too small in size and exists in a custom pad object.

[0056] Step 4: Parse the polygon description method in the polygon object.

[0057] (4.1) According to the polarity of each polygonal object, the objects are divided into solid objects with positive polarity and holes with negative polarity.

[0058] (4.2) Obtain the polygonal outline of each entity and hole, and determine whether the polygonal outline of the entity intersects with the polygonal outline of the hole.

[0059] (4.2.1) If the hole outline is located within the solid outline and there is no overlap between the solid outlines, that is, the hole and the solid are intersecting and the spacing is greater than 0, then the description of the shell and hole group is normal.

[0060] (4.2.2) If the outlines of the hole and the solid do not intersect, or if the outlines of the solids intersect or overlap, then the descriptions of the solids and the hole are considered inconsistent, and a list of inconsistencies is generated (2). The inconsistencies here do not represent absolute errors. Because each vendor's software description method has different fault tolerance capabilities, seemingly contradictory descriptions may be acceptable in some vendors' systems.

[0061] The content of the conflict information list (2) includes:

[0062] (2-1) Figure 1 As shown in the "Wrong Nesting for Hole" section, this indicates a conflicting description of Hole 1 (a negative polygonal object) within a copper surface object. Normally, a hole is located within Entity 2 (a positive polygonal object). This section reports and displays holes that are free and not within a Entity.

[0063] (2-2) Figure 2 As shown in the image, Wrong Nesting for Island: The description of the "entity" in the copper-surfaced object is contradictory. When two "entities" are in a containment relationship, that is, a smaller entity 3 is located within a larger entity 4, the contained smaller "entity" is actually meaningless, indicating a descriptive contradiction.

[0064] Step 5: Analyze whether the polygon object has too short edges.

[0065] (5.1) Obtain the endpoint coordinates of the contour lines of each polygon object in the image graphic description file, breaking the "surface description" into a "contour line description." Furthermore, since polygon objects in the odb++ data format are described using continuous point (endpoint) coordinates, the coordinates of the contour lines of each polygon are directly obtained when the file is read.

[0066] (5.2) Based on the coordinates of the endpoints of the contour line, the length of each side of the polygon is calculated and compared with the preset length threshold. If the side length is less than the length threshold, the side is judged to be too short and a too short edge table (4) is generated.

[0067] The contents of the too short edge table (4) include:

[0068] (4-1) Small Edge in Surface: An edge in a copper surface object that is too short.

[0069] (4-2) Small Edge in Symbol: The short edge of the custom tray object.

[0070] Step 6: Decompose the contour line into multiple point descriptions and generate a self-intersecting edge object table (5).

[0071] Obtain the coordinates of the endpoints of the contour lines that make up the polygonal object in the image graphic description file, and connect two adjacent endpoints to form a line. If the two lines intersect and the intersection point is not the endpoint of the line, it is determined that there is a self-intersecting edge.

[0072] Among them, such as Figure 3 As shown, the contents of the self-intersecting edge object table (5) include:

[0073] (5-1) Self-Intersection in Surface: There are self-intersecting edges in the copper surface object.

[0074] (5-2) Self-Intersection in Symbol: There are self-intersecting edges in the custom pad object.

[0075] Step 7: Obtain the information in (1-1), (2), (3-1), (4-1), and (5-1) and generate a copper surface object risk table (6). The copper surface object risk table includes the polygon object's attribute information, location information, conflict information, and risk level (red, yellow, green).

[0076] Among them, the contents of the copper surface object risk table (6) include: Problematic Surface risk copper surface objects.

[0077] The beneficial effects of the CAM-based copper surface object analysis method of the present invention are: at the micro level, it ensures the yield rate and management efficiency of the manufacturing end; at the macro level, it utilizes the analysis system and method to standardize and integrate the upstream and downstream, accelerates industrial upgrading, and paves the way for fully automatic and fully intelligent PCB manufacturing to open up the entire industry chain.

[0078] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A copper surface object analysis method based on CAM, characterized in that the steps include: (1) Obtain or import the image graphic description file of each layer of PCB circuit board; (2) According to the type information of each object in the image graphic description file, polygonal objects with polygonal attributes are screened out from all objects on the circuit board; (3) Analyze and determine whether polygonal objects contain risk information; (3.1) Determine and analyze the current size information of the polygonal object, compare the current size information with the pre-set size threshold, and generate a list of undersized information and report it; (3.2) Analyze and determine whether the description of polygons in polygonal objects is correct, and generate a list of conflicting information; (3.3) Analyze and determine whether polygonal objects have too short edges, and generate a too short edge table; (3.4) Analyze and determine whether the contour lines of polygonal objects have self-intersecting edges, and generate a self-intersecting edge object table; (4) Obtain the risk information in step (3) and generate a copper surface object risk table.

2. A copper surface object analysis method based on CAM according to claim 1, characterized in that: Image graphic description files include but are not limited to .gerber files, .excellon files, .ipc files, and odb++ files.

3. The copper surface object analysis method based on CAM according to claim 1, characterized in that: Polygonal objects include Surface objects and Symbol objects, among which, Surface object: refers to a copper surface object. When an object is detected as a copper surface object, it is directly judged as a copper surface object and the analysis of step (3) is performed; Symbol object: refers to a custom tray object. When an object is detected as a custom tray object, the symbol description information of the object is obtained and detected to see whether it contains surface attribute information. If it contains surface attribute information, the object is judged to be a custom tray object and the analysis of step (3) is performed.

4. The copper surface object analysis method based on CAM according to claim 1, characterized in that: The current size information of the polygon object includes width information and height information, and the size threshold includes a width threshold and a height threshold.

5. The copper surface object analysis method based on CAM according to claim 1, characterized in that: The steps to determine whether the description of the polygons in the polygon object is correct include: (3.2.1) Classify each polygonal object into a solid object with positive polarity and a hole with negative polarity based on its polarity; (3.2.2) Obtain the polygonal outline of each entity and hole, and determine whether the polygonal outline of the entity intersects the polygonal outline of the hole; (3.2.2.1) If the hole outline is within the solid outline and there is no overlap between the solid outlines, that is, the hole and the solid intersect and the spacing is greater than 0, then the description of the solid and hole is normal; (3.2.2.2) If the outlines of the hole and the solid do not intersect, the descriptions of the solid and the hole are considered inconsistent.

6. The copper surface object analysis method based on CAM according to claim 1, characterized in that: The steps for determining whether a polygon object has too short an edge include: (3.3.1) Obtain the coordinates of the endpoints of the contour lines of each polygonal object in the image graphic description file; (3.3.2) Based on the coordinates of the contour endpoints, calculate the length of each polygon edge and compare the edge length with the preset length threshold. If the edge length is less than the length threshold, the edge is judged to be too short.

7. The copper surface object analysis method based on CAM according to claim 1, characterized in that: The step of analyzing and determining whether the contour line of the polygonal object has a self-intersecting edge includes obtaining the coordinates of the endpoints of the contour lines constituting the polygonal object in the image graphic description file, and connecting two adjacent endpoints to form a line. If the two lines intersect and the intersection point is not the endpoint of the line, it is determined that a self-intersecting edge exists.

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