CN115082393A

CN115082393A - Detection method and device for connecting seam of via holes

Info

Publication number: CN115082393A
Application number: CN202210677587.4A
Authority: CN
Inventors: 倪旭东; 黄大志; 孙煜; 封鹏
Original assignee: Guangdong Industrial Edge Intelligent Innovation Center Co ltd
Current assignee: Guangdong Industrial Edge Intelligent Innovation Center Co ltd
Priority date: 2022-06-15
Filing date: 2022-06-15
Publication date: 2022-09-20

Abstract

The invention provides a detection method and a device for a connecting seam of via holes, wherein the detection method comprises the following steps: identifying all via holes on the PCB to be tested; checking whether at least one through hole group exists in all through holes on the PCB to be tested, wherein each through hole group comprises at least two through holes; in the same via group, the center distance between each via hole and at least one other via hole is considered as a gap and communicated together because the center distance is smaller than the distance threshold value; and determining whether the PCB to be detected is listed as a problem PCB or not according to whether the group number of the checked through hole groups exceeds a group number threshold value or not. The inspection process is automatically carried out through a software algorithm, the problem inspection of the connecting seam of the adjacent via holes on the PCB is realized, manual participation is not needed in the inspection process, the work can be completed in a short time, the working efficiency of PCB wiring is improved, and the working strength is reduced.

Description

Detection method and device for connecting seam of via holes

Technical Field

The invention relates to the technical field of PCB (printed circuit board), in particular to a detection method and a detection device for a via hole connection seam.

Background

When the PCB is designed, holes are often punched to change layer routing, and the communication of complex topology routing is realized. When adjacent via holes are connected together, a gap is formed on the reference ground plane, so that ground impedance is increased, interference is formed, and high-frequency signals passing through the gap are adversely affected. Therefore, the via distance needs to be adjusted to avoid this phenomenon. In the prior art, a PCB is scanned by naked eyes manually, whether all adjacent via holes on the PCB are communicated in a gap or not is checked, and a long gap is formed. However, visual inspection is time consuming, labor intensive, inefficient, and prone to overlooking.

Disclosure of Invention

The invention provides a detection method and a detection device for a via hole connecting seam, which can improve the working efficiency of PCB wiring and reduce the working strength.

In a first aspect, the present invention provides a method for detecting a via connection seam, the method comprising: identifying all via holes on the PCB to be tested; checking whether at least one through hole group exists in all through holes on the PCB to be tested, wherein each through hole group comprises at least two through holes; in the same via group, the center distance between each via hole and at least one other via hole is considered as a gap and communicated together because the center distance is smaller than the distance threshold value; and determining whether the PCB to be detected is listed as a problem PCB or not according to whether the group number of the checked through hole groups exceeds a group number threshold value or not.

In the scheme, the inspection process is automatically carried out through a software algorithm, the problem inspection of the connection seam of the adjacent via holes on the PCB is realized, manual participation is not needed in the inspection process, the work can be completed in a short time, the working efficiency of PCB wiring is improved, and the working strength is reduced.

In a specific embodiment, the spacing threshold satisfies the following condition:

Df＝R1+R2+A1+A2+T

wherein Df represents a spacing threshold; r1 and R2 respectively represent the circle radius of any two adjacent via holes; a1 and A2 respectively represent the distance between any two adjacent via holes and the copper sheet passing through the two via holes; t represents the minimum width of the copper sheet. So as to detect whether two adjacent vias should be considered as being connected together by a gap.

In a specific embodiment, the checking whether at least one via group exists in all the vias on the PCB to be tested includes:

step 1: adding all the via holes on the PCB to be tested into the list A according to a set arrangement sequence;

step 2: sequentially taking out one through hole from the list A, setting the through hole as a through hole V1, and moving the through hole V1 from the list A to a list B1;

and step 3: calculating the center distance between the via V1 and all the vias in the list A, and setting the via closest to the via V1 in the list A as a via V2;

and 4, step 4: judging whether the center distance between the via V1 and the via V2 is greater than a distance threshold value;

if not, then it is determined that the center-to-center spacing between via V1 and via V2 is considered to be slot-connected together because it is less than the spacing threshold;

and if so, sequentially taking out another via from the list A, setting the another via as a via V1, and repeating the steps 2-4 until each via in the list A is taken out and the steps 2-4 are executed. The distance between the adjacent via holes on the PCB to be detected is convenient to detect in sequence.

In a specific embodiment, calculating the center distance of via V1 from all vias in list a, setting the via in list a closest to via V1 as via V2 comprises:

step 31: initially setting the distance Dm to a sufficiently large value to ensure that the distance Dm is greater than the center distance between any two vias in list a and list B1;

step 32: sequentially taking out a via from the list A, calculating the center distance D between the via and the via V1, and comparing D with Dm; if D < Dm, then distance Dm is tentatively set to D, the via is tentatively set to via V2; otherwise, keeping distance Dm and via V2 unchanged;

step 33: the next via continues to be taken out of list a in turn and step 32 is performed until all vias in list a have performed step 32, with the last determined via V2 being the nearest via in list a to via V1. Facilitating the detection of via V2, which is closest to via V1 in list a.

In a specific embodiment, the checking whether at least one via group exists in all the vias on the PCB to be tested further includes:

and 5: if not greater than the center-to-center spacing of via V1 and via V2 is not greater than the spacing threshold, then via V2 is moved from list a into list B1;

step 6: calculating the center distances between all the via holes in the list B1 and all the via holes in the list A to obtain two via holes with the shortest distances in the list A and the list B1; the two via holes are respectively a via hole Va and a via hole Vb, the via hole Va is located in the list A, and the via hole Vb is located in the list B1;

and 7: judging whether the center distance between the via holes Va and Vb is larger than a distance threshold value;

if so, determining that the vias in List B1 are no longer changed, and treating all vias in List B1 as a group of vias;

if not, then via Va is moved from List A to List B1 and steps 6-7 are repeated until it is determined that the vias in List B1 are no longer changed. All other via holes in the same via group can be conveniently detected.

In a specific embodiment, calculating the center distance between all vias in list B1 and all vias in list a, and obtaining the two vias closest to each other in list a and list B1 includes:

step 61: initially setting the distance Dm to a sufficiently large value to ensure that the distance Dm is greater than the center distance between any two vias in list a and list B1;

step 62: taking out a via hole from the list B1, and calculating the center distance Da between the via hole Vx and all the via holes in the list A; comparing Da with Dm, if Da is less than Dm, temporarily setting the via Vx as a via Va, and temporarily setting the distance Dm as Da; otherwise, the via holes Va and Dm are kept unchanged;

and step 63: continuing to take out the next via from list B1, and executing step 62 until all vias in list B1 have executed step 62, and taking the last determined via Va as one of the two vias;

step 64: and calculating the center-to-center distance between the via Va and all the vias in the list B1, and taking the via closest to the via Va in the list B1 as a via Vb. Facilitating the detection of the two closest vias in list a and list B1.

and 8: and sequentially moving out the next via hole from the list A, replacing the via hole V1, moving out the via hole V1 from the list A to the list B2, continuously executing the steps 3-7 until all the members in the list A are moved out, and obtaining the lists B2, B3, B4, B5, …, Bn-1 and Bn. And all the through hole groups on the PCB to be detected are convenient to detect.

In a specific embodiment, determining whether to list the PCB to be tested as the problem PCB according to whether the group number of the checked via hole groups exceeds a group number threshold includes: and determining whether the PCB to be tested is listed as a problem PCB or not according to whether n exceeds the group number threshold value or not. It is convenient to determine whether the PCB is a problem PCB.

In a specific embodiment, the checking whether at least one via group exists in all the vias on the PCB to be tested further includes: and identifying the coordinate value of the first-added via in each list of the lists B1-Bn, so that a user can conveniently locate the coordinate point of the via with a problem.

In a second aspect, the present invention further provides a detection apparatus for detecting a connection seam of via holes, the detection apparatus comprising: the PCB board inspection device comprises an identification module, a via hole group inspection module and a problem PCB board judgment module. The identification module is used for identifying all through holes on the PCB to be detected. The through hole group inspection module is used for inspecting whether at least one through hole group exists in all through holes on the PCB to be inspected; each through hole group comprises at least two through holes; and in the same via group, the center-to-center distance between each via hole and at least one other via hole is considered to be the gap connection because the center-to-center distance is smaller than the distance threshold value. And the problem PCB judging module is used for determining whether the PCB to be detected is listed as a problem PCB or not according to whether the group number of the checked through hole groups exceeds a group number threshold value or not.

In the scheme, the detection device for the connection seam of the via holes formed by the software algorithm and the hardware set automatically performs the inspection process, realizes the problem inspection of the connection seam of the adjacent via holes on the PCB, does not need manual participation in the inspection process, can finish the work in a short time, improves the working efficiency of PCB wiring, and reduces the working strength.

Drawings

Fig. 1 is a flowchart of a method for detecting a via connection seam according to an embodiment of the present invention;

FIG. 2 is a flow chart of another method for detecting a via connection seam according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a spacing threshold according to an embodiment of the present invention;

FIGS. 4 to 9 are schematic diagrams illustrating the division of the list A, the list B1 and the list B2 in the process of checking whether at least one via group exists in all the vias on the PCB to be tested according to the present invention;

fig. 10 is an effect diagram of detecting a PCB to be detected by using the method for detecting a via connection seam according to the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to facilitate understanding of the method for detecting the connecting seam of the via holes provided by the embodiment of the invention, an application scenario of the method for detecting the connecting seam of the via holes of the PCB is described below. The method for detecting the connection gap of the via holes will be described in detail with reference to the accompanying drawings.

Referring to fig. 1, a method for detecting a via connection seam provided by an embodiment of the present invention includes:

step 10: identifying all via holes on the PCB to be tested;

step 20: checking whether at least one through hole group exists in all through holes on the PCB to be tested, wherein each through hole group comprises at least two through holes; in the same via group, the center distance between each via hole and at least one other via hole is considered as a gap and communicated together because the center distance is smaller than the distance threshold value;

step 30: and determining whether the PCB to be detected is listed as a problem PCB or not according to whether the group number of the checked through hole groups exceeds a group number threshold value or not.

In the scheme, the inspection process is automatically carried out through a software algorithm, the problem inspection of the connection seam of the adjacent via holes on the PCB is realized, manual participation is not needed in the inspection process, the work can be completed in a short time, the working efficiency of PCB wiring is improved, and the working strength is reduced. The above steps will be described in detail with reference to the accompanying drawings.

First, referring to fig. 1, fig. 2 and fig. 4, all the via holes on the PCB to be tested are identified, that is, information such as coordinate positions and radius sizes of all the via holes on the PCB to be tested is identified.

Next, referring to fig. 1 and 2, it is checked whether at least one via group exists in all the via holes on the PCB to be tested. Wherein, each through hole group comprises at least two through holes. And in the same via group, the center-to-center distance between each via hole and at least one other via hole is considered to be the gap connection because the center-to-center distance is smaller than the distance threshold value. That is, the plurality of via holes in each via hole group are considered to be connected together by the gaps due to the closer distance, which is smaller than the spacing threshold.

In determining the pitch threshold, the pitch threshold is specifically related to the radius of the via, the distance of the via from the copper sheet around the via, and the minimum width of the copper sheet. For example, referring to fig. 3, the pitch threshold may satisfy the following condition:

Df＝R1+R2+A1+A2+T

wherein Df represents a spacing threshold; r1 and R2 respectively represent the circle radius of any two adjacent vias; a1 and A2 respectively represent the distance between any two adjacent via holes and the copper sheet passing between the two via holes; t represents the minimum width of the copper sheet. So as to detect whether two adjacent vias should be considered as being connected together by a gap. It should be understood that the above illustrates only one way of determining the spacing threshold, and that other ways of determining may be used in addition. For example, a spacing threshold can be preset during design.

When checking whether at least one via group exists in all via holes on the PCB to be tested, referring to fig. 2 and 4, the following steps may be adopted to detect whether the first via group exists:

step 2: sequentially taking out one through hole from the list A, setting the through hole as a through hole V1, and moving the through hole V1 from the list A to a list B1; taking the skill language as an example, the above operation can be implemented by the following command codes: foreach (V1 a … …); v1 ═ remq (a 1V 1); b1 ═ apend (B1V 1);

and if so, sequentially taking out another via from the list A, setting the another via as a via V1, and repeating the steps 2-4 until each via in the list A is taken out and the steps 2-4 are executed. The distance between the adjacent via holes on the PCB to be detected is convenient to detect in sequence. It should be understood that the way of detecting the first group of via holes is not limited to the above illustrated way, but other ways may be used.

The above-mentioned calculation of the center distances between the via V1 and all the vias in the list a may be performed by the following steps when the via closest to the via V1 in the list a is set as the via V2:

step 31: initially setting the distance Dm to a sufficiently large value to ensure that the distance Dm is greater than the center distance between any two vias in list a and list B1; for example, distance Dm may be initially set to 99999 inches;

step 33: the next via continues to be taken out of list a in turn and step 32 is performed until all vias in list a have performed step 32, with the last determined via V2 being the nearest via in list a to via V1. Facilitating the detection of via V2, which is closest to via V1 in list a. It should be understood that the above only shows one way of calculating the center distance of via V1 from all the vias in list a, and that the via in list a closest to via V1 is set as via V2, but other ways may be used.

In addition, referring to fig. 2 and 5 to 8, when checking whether there is at least one via group in all via holes on the PCB to be tested, after the steps 1 to 4 are performed, the following steps 5 to 7 may be further performed to detect all other via holes in the same via group when the following conditions are satisfied:

and 5: if the result of determining whether the center-to-center spacing of via V1 and via V2 is greater than the spacing threshold is not greater than, then moving via V2 from list a into list B1;

if not, then via Va is moved from List A to List B1 and steps 6-7 are repeated until it is determined that the vias in List B1 are no longer changed. All other via holes in the same via group can be conveniently detected. It should be understood that the above only shows one way of detecting all other vias in the same group of vias, but that other ways may be used.

When the distances between all the vias in the list B1 and all the vias in the list a are calculated to obtain the two vias closest to each other in the list a and the list B1, referring to fig. 4 and fig. 5 to 8, the following steps may be adopted:

step 61: initially setting the distance Dm to a sufficiently large value to ensure that the distance Dm is greater than the center distance between any two vias in list a and list B1; for example, distance Dm may be initially set to 99999 inches;

step 64: and calculating the center-to-center distance between the via Va and all the vias in the list B1, and taking the via closest to the via Va in the list B1 as a via Vb. Facilitating the detection of the two closest vias in list a and list B1. It should be understood that the above only illustrates one way to detect the nearest two vias in list a and list B1, and that other ways may be used in addition.

In addition, referring to fig. 2 and 9, when checking whether there is at least one via hole group in all via holes on the PCB to be tested, after performing steps 1 to 7 as follows, the following step 8 may be further performed to detect another via hole group on the PCB to be tested:

When whether at least one through hole group exists in all the through holes on the PCB to be detected is checked, and when each list of the lists B1-Bn is determined, the coordinate value of the first-added through hole in each list of the lists B1-Bn can be further identified, and a user can conveniently position the coordinate point of the through hole with a problem.

Next, referring to fig. 1 and 2, according to whether the number of groups of the checked through hole groups exceeds the group number threshold, it is determined whether the PCB to be tested is listed as a problem PCB. For example, the set number threshold may be 5, 6, 7, 8, 9, etc. Specifically, lists B1, B2, B3, B4, B5, …, Bn-1, Bn may be traversed to obtain the number n in list B. And then, determining whether the PCB to be tested is listed as a problem PCB or not according to whether the number n in the list B exceeds the group number threshold or not. It is convenient to determine whether the PCB is a problem PCB.

Furthermore, lists B1-Bn on the PCB to be tested can be used as different problem points and added into the problem list P.

In the various embodiments shown above, the inspection process is automatically performed through a software algorithm, so that the problem inspection of the connection seam between adjacent via holes on the PCB is realized, no manual intervention is required in the inspection process, the work can be completed in a short time, the work efficiency of PCB wiring is improved, and the work intensity is reduced. As shown in the effect diagram 10, in the actual test, the inspection of 3786 via holes on the PCB to be tested can be automatically completed within 61 seconds, 4 problem points are found, each problem point has a coordinate report (as shown in the position outlined in fig. 10), and the manual inspection takes at least 5 minutes. The comparison shows that the efficiency is improved by more than 5 times.

In addition, an embodiment of the present invention further provides a device for detecting a connection gap between vias, and referring to fig. 1 and 2, the device includes: the PCB board inspection device comprises an identification module, a via hole group inspection module and a problem PCB board judgment module. The identification module is used for identifying all through holes on the PCB to be detected. The through hole group inspection module is used for inspecting whether at least one through hole group exists in all through holes on the PCB to be inspected; each through hole group comprises at least two through holes; and in the same via group, the center-to-center distance between each via hole and at least one other via hole is considered to be the gap connection because the center-to-center distance is smaller than the distance threshold value. And the problem PCB judging module is used for determining whether the PCB to be detected is listed as a problem PCB or not according to whether the group number of the checked through hole groups exceeds a group number threshold value or not. The detection device for the via hole connection seam formed by software algorithm and hardware set automatically performs the inspection process, realizes the problem inspection of the connection seam of adjacent via holes on the PCB, does not need manual participation in the inspection process, can finish the work in a short time, improves the working efficiency of PCB wiring, and reduces the working strength.

It should be explained that each of the functional modules in the identification module, the via group inspection module and the problem PCB judgment module is a functional module formed by a set of software and hardware, and the software can execute the corresponding steps in the method for detecting the via connection seams.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A detection method for connecting a via hole into a seam is characterized by comprising the following steps:

identifying all via holes on the PCB to be tested;

checking whether at least one through hole group exists in all through holes on the PCB to be tested; each through hole group comprises at least two through holes; in the same via group, the center distance between each via hole and at least one other via hole is considered as a gap and communicated together because the center distance is smaller than the distance threshold value;

and determining whether the PCB to be detected is listed as a problem PCB or not according to whether the group number of the checked through hole groups exceeds a group number threshold value or not.

2. The detection method according to claim 1, wherein the spacing threshold satisfies the following condition:

Df＝R1+R2+A1+A2+T

wherein Df represents the spacing threshold;

r1 and R2 respectively represent the circle radius of any two adjacent vias;

a1 and A2 respectively represent the distance between any two adjacent via holes and the copper sheet passing between the two via holes;

t represents the minimum width of the copper sheet.

3. The method for inspecting as claimed in claim 2, wherein said inspecting whether there is at least one via group in all vias on the PCB board to be inspected comprises:

step 1: adding all the via holes on the PCB to be tested into a list A according to a set arrangement sequence;

step 2: sequentially taking out a via from the list A, setting the via as a via V1, and moving the via V1 from the list A to a list B1;

and 4, step 4: judging whether the center-to-center distance between the via V1 and the via V2 is greater than the distance threshold value;

if not, determining that the center-to-center spacing between via V1 and via V2 is considered to be slot-connected together because it is less than the spacing threshold;

and if so, sequentially taking out another via from the list A, setting the another via as the via V1, and repeating the steps 2-4 until each via in the list A is taken out and the steps 2-4 are executed.

4. The inspection method of claim 3, wherein said calculating a center distance of said via V1 from all vias in said list A, setting a via in said list A that is closest to said via V1 as via V2 comprises:

step 31: initially setting the distance Dm to a value large enough to ensure that the distance Dm is greater than the center distance between any two vias in the list a and the list B1;

step 32: sequentially taking out a via from the list A, calculating the center distance D between the via and the via V1, and comparing D with Dm; if D < Dm, temporarily defining the distance Dm as D, and temporarily defining the via as the via V2; otherwise, keeping distance Dm and via V2 unchanged;

step 33: and continuing to sequentially take out the next via from the list A, and executing the step 32 until all the vias in the list A execute the step 32, and taking the last determined via V2 as the via closest to the via V1 in the list A.

5. The method as claimed in claim 3, wherein said checking whether there is at least one via group in all the vias on the PCB board to be tested further comprises:

and 5: moving the via V2 out of the list A into the list B1 if the center-to-center spacing of the via V1 and via V2 is not greater than the spacing threshold;

step 6: calculating the center distances between all the vias in the list B1 and all the vias in the list A, and obtaining two vias with the shortest distance in the list A and the list B1; the two vias are respectively a via Va and a via Vb, the via Va is located in the list A, and the via Vb is located in the list B1;

and 7: judging whether the center distance between the via holes Va and Vb is larger than the distance threshold value;

if so, determining that the vias in the list B1 are no longer changed, and treating all vias in the list B1 as one of the via groups;

if not, the via Va is moved from the list A into the list B1 and steps 6-7 are repeated until it is determined that the vias in the list B1 are no longer changed.

6. The method of claim 5, wherein said calculating the center distance of all vias in said List B1 from all vias in said List A, obtaining the two vias in said List A and List B1 that are the closest comprises:

step 61: initially setting the distance Dm to a value large enough to ensure that the distance Dm is greater than the center distance between any two vias in the list a and the list B1;

step 62: taking out a via hole from the list B1, and calculating the center distance Da between the via hole Vx and all the via holes in the list A; comparing Da with Dm, if Da is less than Dm, temporarily setting the via Vx as the via Va, and temporarily setting the distance Dm as Da; otherwise, the via holes Va and Dm are kept unchanged;

and step 63: continuing to take the next via from the list B1, executing the step 62 until all vias in the list B1 have executed the step 62, and regarding the last determined via Va as one of the two vias;

step 64: and calculating the center-to-center distances between the via hole Va and all the via holes in the list B1, and taking the via hole closest to the via hole Va in the list B1 as the via hole Vb.

7. The method for inspecting as claimed in claim 5, wherein said inspecting whether there is at least one via group in all vias on said PCB under test further comprises:

and 8: and sequentially removing the next via hole from the list A, replacing the via hole V1, removing the via hole V1 from the list A to a list B2, continuously executing the steps 3-7 until all members in the list A are removed, and obtaining lists B2, B3, B4, B5, …, Bn-1 and Bn.

8. The method as claimed in claim 7, wherein determining whether to list the PCB to be tested as a problem PCB according to whether the number of groups of the checked through holes exceeds a group number threshold comprises:

and determining whether the PCB to be tested is listed as a problem PCB or not according to whether the n exceeds the group number threshold value or not.

9. The method according to claim 7, wherein said checking whether at least one via group exists among all vias on the PCB board to be tested further comprises:

the coordinate values of the first-added via in each of the lists B1-Bn are identified.

10. A detection device for connecting via holes into seams is characterized by comprising:

the identification module is used for identifying all through holes on the PCB to be detected;

the through hole group inspection module is used for inspecting whether at least one through hole group exists in all through holes on the PCB to be tested; each through hole group comprises at least two through holes; in the same via group, the center distance between each via hole and at least one other via hole is considered as a gap and communicated together because the center distance is smaller than the distance threshold value;

and the problem PCB judging module is used for determining whether the PCB to be detected is listed as a problem PCB or not according to whether the group number of the checked through hole groups exceeds a group number threshold value or not.