High-density interconnect via chain test board and manufacturing method therefor

Abstract

A high-density interconnect via chain test board and a manufacturing method therefor. The manufacturing method for a high-density interconnect via chain test board comprises: acquiring a high-density interconnect printed circuit board; and performing pre-cycling routing processing on a via chain region of the high-density interconnect printed circuit board, so as to obtain the high-density interconnect via chain test board. By means of the pre-cycling routing processing of the via chain region of the high-density interconnect printed circuit board, lines and vias as well as layers and layers within the via chain region of the high-density interconnect printed circuit board are interconnected, that is, a connection state between the layers of the high-density interconnect printed circuit board is reflected by means of an open / short circuit condition between the layers in the via chain region, thereby facilitating the determination of the open / short circuit condition between inner and outer layers of the high-density interconnect printed circuit board, and effectively improving the accuracy of open / short circuit detection between the layers of the high-density interconnect printed circuit board.

Description

High-density interconnection hole chain test plate and preparation method thereof TECHNICAL FIELD

[0001] The present application relates to a high-density interconnection hole chain test plate and a preparation method thereof. BACKGROUND

[0002] PCB (Printed Circuit Board, i.e. printed circuit board) has at least one conductive pattern attached thereto and is provided with holes and grooves to realize the mutual connection between electronic components, which is almost the basis of all electronic products. Generally speaking, if there are electronic components in a certain device, they are also integrated on PCB boards of different sizes. Electronic components are becoming lighter, thinner, more functional and integrated design, and PCB boards usually adopt the way of laminated multi-layer circuit to realize high-density integration.

[0003] With the increase of information transmission rate and information transmission amount, electronic products are becoming smaller and smaller in size, PCB board packaging size is continuously shrinking, and component performance and wiring density are continuously rising, which requires continuous improvement of the interconnection density of PCB substrate, i.e. HDI-PCB. In the production process of HDI-PCB board, problems such as insufficient hole copper thickness, ICD (Inner connection defects, inner layer interconnection defects) separation, blind hole bottom residue, and blind hole bottom cracking cannot be detected for a long time, which leads to circuit disconnection during use, brings poor user experience and safety hazards to end users, and causes huge compensation to PCB board manufacturing enterprises. The current method for detecting HDI blind hole problems is to design a simple hole chain link as a COUPON and use a high-current tester for single-point testing, for example, patent applications CN201410857672.4 and CN202211045187.8. However, this type of hole chain link COUPON test strip cannot effectively reflect the open circuit problem between the lines and holes, layers and layers of the HDI board, and often misses or misdiagnoses. SUMMARY

[0004] Therefore, it is necessary to provide a high-density interconnection hole chain test plate and a preparation method thereof to improve the detection accuracy of open circuit between layers.

[0005] A high-density interconnection hole chain test plate preparation method, the method comprises:

[0006] Obtaining a high-density interconnection printed substrate;

[0007] Pre-circulating the hole chain area of the high-density interconnection printed substrate to obtain a high-density interconnection hole chain test plate.

[0008] The high-density interconnection hole chain test board is prepared by the high-density interconnection hole chain test board preparation method.

[0009] The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description only represent some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0011] Fig. 1 is a flow chart of the high-density interconnection hole chain test board preparation method in an embodiment;

[0012] Fig. 2 is a schematic diagram of inner layer wiring in an embodiment;

[0013] Fig. 3 is a schematic diagram of outer layer wiring in an embodiment. DETAILED DESCRIPTION

[0014] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present application can be more thoroughly and completely understood.

[0015] It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or there can be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can be present. As used herein the terms "vertical", "horizontal", "left", "right" and the like are merely used for the purpose of illustration and are not intended to be limiting.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0017] Referring to FIG. 1, it is a flow chart of a high-density interconnection hole chain test board preparation method according to an embodiment of the present disclosure. The high-density interconnection hole chain test board preparation method includes some or all of the following steps.

[0018] S100: Obtain a high-density interconnection printed board.

[0019] In the embodiment, the high-density interconnection printed board is a base board of a high-density interconnection printed circuit board, specifically, the high-density interconnection printed board is a circuit board with completed inner and outer layer circuits. At this time, the hole chain area of the high-density interconnection printed board is processed by the same board manufacturing process, that is, each layer and hole of the hole chain area is processed by the same circuit manufacturing process. This facilitates the hole ring test of the hole chain area to realize the test of the entire high-density interconnection printed circuit board, which not only improves the test accuracy, but also saves the test cost.

[0020] S200: Perform pre-circulation wiring processing on the hole chain area of the high-density interconnection printed board to obtain a high-density interconnection hole chain test board.

[0021] In the embodiment, the high-density interconnection printed board is a base board of a high-density interconnection printed circuit board, specifically, the high-density interconnection printed board is a circuit board with completed inner and outer layer circuits. At this time, the hole chain area of the high-density interconnection printed board is processed by the same board manufacturing process, that is, each layer and hole of the hole chain area is processed by the same circuit manufacturing process. This facilitates the hole ring test of the hole chain area to realize the test of the entire high-density interconnection printed circuit board, which not only improves the test accuracy, but also saves the test cost. In the pre-circulation wiring processing of the hole chain area, wiring is performed on the specified circulation route to electrically connect each layer and hole in the hole chain area, which facilitates the formation of a hole chain path for testing, thereby facilitating the open circuit test of the hole chain area through the hole chain path, and further facilitating the open circuit test of the circuits and holes, and layers and layers of the high-density interconnection printed circuit board.

[0022] In the above embodiment, the pre-circulation wiring processing of the hole chain area of the high-density interconnection printed board connects the circuits and holes, and layers and layers in the hole chain area of the high-density interconnection printed board, that is, the open circuit condition between each layer in the hole chain area reflects the connection state between each layer of the high-density interconnection printed board, which facilitates the determination of the open circuit condition between the inner and outer layers of the high-density interconnection printed board, and effectively improves the open circuit detection accuracy between each layer of the high-density interconnection printed board.

[0023] In one embodiment, the high-density interconnection printed substrate is obtained, and then further comprising: obtaining a test hole type of a hole chain area of the high-density interconnection printed substrate. In this embodiment, the high-density interconnection printed substrate is a base plate of a high-density interconnection printed circuit board, specifically, the high-density interconnection printed substrate is a circuit board with inner and outer layer circuits completed, at this time, the hole chain area of the high-density interconnection printed substrate is processed by the same plate making process, that is, each layer and hole of the hole chain area is processed by the same circuit making process, so as to realize the test of the whole high-density interconnection printed circuit board through the hole ring test of the hole chain area, which not only improves the test accuracy, but also saves the test cost. The inner and outer layer circuits of the high-density interconnection printed substrate have been completed, each type of hole on the high-density interconnection printed substrate is also completed synchronously, and the hole chain area and the high-density interconnection printed substrate adopt the same plate making process, so that the connection state between the circuit and the hole, and between the layers of the hole chain area is the same. The test hole type is the type of the hole to be tested in the hole chain area, that is, the test hole type corresponds to the hole to be tested in the hole chain area, and the test hole in the hole chain area corresponds to the hole at other positions of the high-density interconnection printed substrate, so as to realize the equivalent test of the whole hole ring of the high-density interconnection printed substrate through the test of different test holes of the hole chain area, thereby facilitating the accurate test of the open circuit state between the circuit and the hole, and between the layers of the high-density interconnection printed substrate.

[0024] Further, the pre-circulation wiring processing of the hole chain area of the high-density interconnection printed substrate includes: according to the test hole type, wiring the hole chain according to the preset wiring. In the embodiment, the high-density interconnection printed substrate is a basic board of high-density interconnection printed circuit board, specifically, the high-density interconnection printed substrate is a circuit board with inner and outer layers of circuit completed, at this time, the hole chain area of the high-density interconnection printed substrate is processed by the same circuit board processing procedure, that is, each layer of the hole chain area and the hole are processed by the same circuit manufacturing process, so that the test of the hole ring of the whole high-density interconnection printed circuit board can be realized through the hole ring test of the hole chain area, which not only improves the test accuracy, but also saves the test cost. The inner and outer layers of the high-density interconnection printed substrate have been completed, and each type of hole on the high-density interconnection printed substrate is also completed synchronously, and the hole chain area and the high-density interconnection printed substrate adopt the same circuit board processing procedure, so that the connection state between the circuit and the hole, and the layer and the layer of the hole chain area is the same. The test hole type is the type of the hole to be tested in the hole chain area, that is, the test hole type corresponds to the hole in the hole chain area for open circuit test, and the test hole in the hole chain area corresponds to the hole at other positions of the high-density interconnection printed substrate, so that the test of different test holes in the hole chain area is equivalent to the test of all hole rings of the high-density interconnection printed substrate, thereby facilitating the accurate test of the open circuit state between the circuit and the hole, and the layer and the layer of the high-density interconnection printed substrate. After determining the hole type of the test hole in the hole chain area, that is, the test hole type, wiring according to the specified wiring mode for different hole types to electrically connect each hole wall in the hole chain area, so as to electrically connect each layer of the hole chain area, thereby facilitating the determination of the open circuit state between the circuit and the hole, and the layer and the layer of the hole chain area.

[0025] Further, the hole chain wiring according to the preset wiring mode of the test hole type comprises: detecting whether the test hole type matches the test via hole; and when the test hole type matches the test via hole, respectively performing inner layer wiring and outer layer wiring on the hole chain area of the high-density interconnection printed substrate. In the embodiment, the high-density interconnection printed substrate is a basic board of a high-density interconnection printed circuit board, specifically, the high-density interconnection printed substrate is a circuit board on which inner and outer layer circuits are completed, at this time, the hole chain area of the high-density interconnection printed substrate is processed by the same board processing procedure, that is, each layer and hole of the hole chain area are processed by the same circuit processing technology, so that the test on the entire high-density interconnection printed circuit board can be realized through hole ring test of the hole chain area, which not only improves the test accuracy, but also saves the test cost. The inner and outer layer circuits of the high-density interconnection printed substrate are completed, each type of hole on the high-density interconnection printed substrate is also completed synchronously, and the hole chain area and the high-density interconnection printed substrate are processed by the same board processing procedure, so that the connection state between the circuits and holes and between the layers of the hole chain area is the same. The test hole type is the type of the hole to be tested in the hole chain area, that is, the test hole type corresponds to the hole in the hole chain area which is subjected to open circuit test, and the test hole in the hole chain area corresponds to the hole at other positions of the high-density interconnection printed substrate, so that the test on different test holes of the hole chain area is equivalent to the test on all hole rings of the high-density interconnection printed substrate, thereby facilitating accurate test on the open circuit state between the circuits and holes and between the layers of the high-density interconnection printed substrate. When the hole type of the test hole in the hole chain area, that is, the test hole type, is determined, wiring is performed according to the specified wiring mode for different hole types, so as to electrically connect each hole wall in the hole chain area, electrically connect each layer circuit of the hole chain area, and determine the open circuit state between the circuits and holes and between the layers of the hole chain area. The test via hole is a specified via hole type, the test hole type matches the test via hole, which indicates that there is a via hole in the hole chain area, at this time, the hole chain area has two different levels of inner and outer layers, and has inner layer wiring and outer layer wiring, so as to form inner layer hole chain paths and outer layer hole chain paths, thereby facilitating the test on the open circuit state between the inner and outer layer circuits and holes and between the layers, respectively, to improve the test accuracy.

[0026] Further, the inner layer wiring of the via chain region of the high-density interconnection printed board comprises: step-by-step circular wiring along the inner layer in the via chain region. In the embodiment, the via chain region has through holes, and the inner layer wiring of the via chain region forms via chain links between the inner layer circuit and the via, and between the inner layer and the inner layer. Specifically, the step-by-step circular wiring along the inner layer in the via chain region facilitates the electrical connection of the inner layer circuit of the via chain region through the via chain links, i.e., the electrical connection of the inner layer circuits of the via chain region through copper wires, thereby facilitating the test of the open-circuit state between the inner layer circuit and the via, and between the inner layer and the inner layer.

[0027] In another embodiment, the number of layers of the inner layer wiring is in an arithmetic progression, and the circular mode of the via chain links is as follows: L1->L6->L2->L7->L3->L8->L4->L9->L5->L10, as shown in detail in FIG. 2.

[0028] In one embodiment, the outer layer wiring of the via chain region of the high-density interconnection printed board comprises: reciprocating wiring of the upper and lower outer layers in the via chain region. In the embodiment, the via chain region has through holes, and the outer layer wiring of the via chain region forms via chain links between the outer layer circuit and the via, and between the upper and lower outer layers. The reciprocating wiring of the upper and lower outer layers in the via chain region, specifically, the circular mode of the via chain links is as follows: L1->L10->L1->L10->L1->L10, as shown in detail in FIG. 3, facilitating the electrical connection of the outer layer circuit of the via chain region through the via chain links, i.e., the electrical connection of the upper and lower outer layer circuits of the via chain region through copper wires, thereby facilitating the test of the open-circuit state between the outer layer circuit and the via, and between the upper and lower outer layers.

[0029] In one embodiment, the detection of whether the test hole type matches the test through hole is followed by: when the test hole type does not match the test through hole, detecting whether the test hole type matches the test blind hole; and when the test hole type matches the test blind hole, performing double-sided outer layer wiring of the via chain region of the high-density interconnection printed board. In the embodiment, the test hole type does not match the test through hole, and the test hole type matches the test blind hole, indicating that the via in the via chain region is a blind hole. At this time, the via in the via chain region is a non-through hole, i.e., a non-through hole, and the via in the via chain region appears on both the front and back surfaces and is not connected to each other. When forming the via chain links, the blind holes in the via chain region need to be wired on the outer layer. Specifically, the two groups of blind holes are symmetrical on the front and back surfaces, i.e., 200 blind holes on each of the front and back surfaces. The outer layer circuit of one surface is first wired, and then the other surface is wired through the right through hole. The wiring is performed in the manner of through hole outer layer wiring, so as to electrically connect the circuits corresponding to the blind holes on both sides and form the required test via chain links.

[0030] Further, the detecting whether the test hole type matches the test blind hole further comprises: when the test hole type does not match the test blind hole, detecting whether the test hole type matches a test buried hole; and when the test hole type matches the test buried hole, performing multi-layer inner-layer wiring on the hole chain area of the high-density interconnection printed board. In the embodiment, the test hole type does not match the test blind hole, and the test hole type matches the test buried hole, which indicates that the holes in the hole chain area are buried holes. At this time, the holes in the hole chain area are embedded holes, the holes in the hole chain area appear between inner layers and are not in communication with the outside, and inner-layer wiring needs to be performed on the buried holes in the hole chain area when forming a hole chain link. Specifically, the buried hole module is composed of 48 buried holes, and the buried hole wiring is performed according to the principle of through-hole inner-layer wiring.

[0031] In the actual hole chain link wiring process of the hole chain area of the high-density interconnection printed board, the hole chain area and the holes outside the hole chain area of the high-density interconnection printed board are manufactured by the same process, wiring is performed in the hole chain area to form a hole chain link, and the side surface reflects the disconnection condition of the lines and holes, layers and layers outside the hole chain area. However, the hole chain area is usually at the edge of the high-density interconnection printed board, which is convenient for cutting and removing after testing is completed. The stress of the plate edge is smaller than that of the plate middle during pressing, which causes partial holes in the hole chain area to be offset by force, thereby easily causing the wiring path of the hole chain link to deviate, and further easily causing the hole chain link to be virtually connected with the hole wall, thereby affecting the testing accuracy.

[0032] To solve the above problems, the pre-circulation wiring process of the hole chain area of the high-density interconnection printed board to obtain a high-density interconnection hole chain test board further comprises the following steps:

[0033] Obtaining a hole core image of the hole chain area;

[0034] Obtaining a hole core spacing according to the hole core image;

[0035] Detecting whether the hole core spacing is less than a preset spacing;

[0036] When the hole core spacing is less than the preset spacing, gradually increasing the cross-hole link of the pre-circulation wiring.

[0037] In the embodiment, the hole core image is a current surface image of the hole chain area, and the hole core image is used to show the distribution of holes in the hole chain area. Specifically, the hole core image can be acquired by a CCD camera with a spectrum function, that is, a combination of a spectrum analyzer and a camera device, so as to facilitate the acquisition of the distribution of through holes, blind holes and buried holes in the hole chain area. The hole core image contains the planar distribution of each hole, and the hole core spacing is the distance between each hole in the hole chain area, which is used to reflect the density of the adjacent hole distribution in the hole chain area. The hole core spacing is smaller than the preset spacing, indicating that the hole distribution in the hole chain area is too dense. Specifically, the hole spacing away from the plate edge in the hole chain area is smaller. At this time, the holes in the hole chain area are not uniformly distributed, and the hole spacing gradually increases in the direction close to the plate edge. The cross-hole link of the gradual increase pre-circulation is used to gradually increase the cross-hole spacing of the hole link in the direction close to the plate edge, so as to adapt to the hole distribution in the hole chain area, thereby maintaining firm electrical connection between the hole link and the hole wall.

[0038] Further, the detection of whether the hole core spacing is smaller than the preset spacing further includes:

[0039] When the hole core spacing is greater than or equal to the preset spacing, the hole core diameter is acquired according to the hole core image.

[0040] The hole core diameter is detected whether it is smaller than the preset hole diameter.

[0041] When the hole core diameter is smaller than the preset hole diameter, a first circulation is selected to distribute the hole link from the center to the edge of the hole chain area.

[0042] In the embodiment, the hole core spacing is greater than or equal to the preset spacing, indicating that the hole distribution in the hole chain area is uniform. At this time, the hole diameter of each hole in the hole chain area is acquired through the hole core image, that is, the hole core diameter, which is used to reflect the hole type distribution in the hole chain area. The hole core diameter is smaller than the preset hole diameter, indicating that there are staggered holes and buried holes in the hole chain area, and the staggered holes are located at the center of the hole chain area, and the buried holes are distributed at other positions. The staggered hole is a combination hole of a buried hole and a through hole which are stacked and misaligned. The buried hole is a combination hole of a buried hole and a through hole which are stacked and distributed on the same vertical line. At this time, the hole type distribution in the hole chain area is determined, and the pre-circulation is processed in the first circulation mode, so that the hole link in the hole chain area is preferentially wired to the staggered hole, and then wired to the buried hole, so as to wire different types of holes, so that the test wiring in the hole chain area is more reasonable, and repeated wiring between different types of holes is avoided, thereby reducing the cost of hole link wiring.

[0043] In another embodiment, when the hole core diameter is greater than or equal to the preset hole diameter, a second loop wiring is selected to distribute the hole links from the edge of the hole chain area to the center. At this time, the holes in the hole chain area are through holes or buried holes, that is, the holes in each layer are on the same axis, and the second loop wiring is used for wiring, which facilitates the conventional wiring distribution of holes similar to through holes, thereby improving the wiring efficiency.

[0044] In one embodiment, the present disclosure also relates to a high-density interconnection hole chain test board prepared by the high-density interconnection hole chain test board preparation method of any of the above embodiments. In this embodiment, the high-density interconnection hole chain test board preparation method comprises obtaining a high-density interconnection printed board; and performing pre-loop wiring processing on the hole chain area of the high-density interconnection printed board to obtain a high-density interconnection hole chain test board. By performing pre-loop wiring processing on the hole chain area of the high-density interconnection printed board, the lines in the hole chain area of the high-density interconnection printed board are connected with the holes and the layers, that is, by breaking the circuit between each layer in the hole chain area, the connection state between each layer of the high-density interconnection printed board is reflected, which facilitates the determination of the open circuit condition between the inner and outer layers of the high-density interconnection printed board, and effectively improves the detection accuracy of the open circuit between each layer of the high-density interconnection printed board.

[0045] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above embodiments are not described, but as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present disclosure.

[0046] The above embodiments only express several embodiments of the present disclosure, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present disclosure, a number of modifications and improvements can be made, which are within the scope of the present disclosure. Therefore, the protection scope of the present patent should be subject to the appended claims.

Claims

1. A method for preparing a high-density interconnection well-chain test plate, characterized by, The method comprises the steps of: obtaining a high-density interconnection printed board; pre-circulating wiring of a hole chain area of the high-density interconnection printed board to obtain a high-density interconnection hole chain test board.

2. The method of claim 1, wherein the method further comprises: The step of obtaining the high-density interconnection printed board further comprises: obtaining a test hole type of the hole chain area of the high-density interconnection printed board.

3. The method of claim 2, wherein the method further comprises: The test hole type is the type of a hole to be tested in the hole chain area.

4. The method of claim 2, wherein the method further comprises: The test hole type corresponds to a hole subjected to an open circuit test in the hole chain area.

5. The method of claim 2, wherein the method further comprises: The step of pre-circulating wiring of the hole chain area of the high-density interconnection printed board comprises: wiring the hole chain according to a preset wiring according to the test hole type.

6. The method of claim 5, wherein the method further comprises: The step of wiring the hole chain according to the preset wiring according to the test hole type comprises: wiring according to a specified wiring mode to electrically connect each hole wall in the hole chain area.

7. The method of claim 5, wherein the method further comprises: The step of wiring the hole chain according to the preset wiring according to the test hole type comprises: detecting whether the test hole type matches a test via hole; when the test hole type matches the test via hole, respectively performing inner layer wiring and outer layer wiring of the hole chain area of the high-density interconnection printed board.

8. The method of claim 7, wherein the method further comprises: The step of performing inner layer wiring of the hole chain area of the high-density interconnection printed board comprises: gradually circulating wiring along the inner layer in the hole chain area.

9. The method of claim 8, wherein the method further comprises: The step of gradually circulating wiring along the inner layer in the hole chain area comprises: electrically connecting each inner layer circuit of the hole chain area by a copper wire.

10. The method of claim 8, wherein the method further comprises: The number of layers of the inner layer wiring is in an arithmetic progression.

11. The method of claim 7, wherein the method further comprises: The step of performing outer layer wiring of the hole chain area of the high-density interconnection printed board comprises: ​ reciprocally wiring the upper and lower outer layers in the hole chain area.

12. The method of claim 11, wherein the method further comprises: electrically connecting the upper and lower outer layer circuits of the hole chain area by a copper wire.

13. The method of claim 7, wherein the method further comprises: The step of detecting whether the test hole type matches a test via hole further comprises: ​ when the test hole type does not match the test via hole, detecting whether the test hole type matches a test blind hole; when the test hole type matches the test blind hole, performing double-sided outer layer wiring of the hole chain area of the high-density interconnection printed board.

14. The method of claim 13, wherein the method further comprises: The step of performing double-sided outer layer wiring of the hole chain area of the high-density interconnection printed board comprises: wiring according to a via outer layer wiring mode to electrically connect the circuits corresponding to the blind holes on the two sides by first wiring the outer layer circuit of one side and then wiring the other side through the right via hole.

15. The method of claim 13, wherein the method further comprises: The step of detecting whether the test hole type matches a test blind hole further comprises: ​ when the test hole type does not match the test blind hole, detecting whether the test hole type matches a test buried hole; when the test hole type matches the test buried hole, performing multi-layer inner layer wiring of the hole chain area of the high-density interconnection printed board.

16. The method of claim 1, wherein the method further comprises: The method further comprises the following steps before the step of obtaining the high-density interconnection printed board: obtaining a hole core image of the hole chain area; obtaining a hole core spacing according to the hole core image; detecting whether the hole core spacing is less than a preset spacing; when the hole core spacing is less than the preset spacing, gradually increasing a cross-hole link of the pre-circulating wiring.

17. The method of claim 16, wherein the method further comprises: The step of detecting whether the hole core spacing is less than a preset spacing further comprises: when the hole core spacing is greater than or equal to the preset spacing, obtaining a hole core diameter according to the hole core image; detecting whether the hole core diameter is less than a preset hole diameter; when the hole core diameter is less than the preset hole diameter, selecting a first cycle routing to make the hole chain link distribute from the center to the edge of the hole chain area.

18. The method of claim 17, wherein the method further comprises: The first cycle routing is to route the misaligned holes first and then route the buried holes. ​ 19. The method of claim 17, wherein the method further comprises: providing a plurality of high density interconnect via chain test boards; and providing a plurality of test probes, wherein each test probe is configured to be inserted into a corresponding one of the plurality of high density interconnect via chain test boards. when the hole core diameter is greater than or equal to the preset hole diameter, selecting a second cycle routing to make the hole chain link distribute from the edge to the center of the hole chain area.

20. The method of claim 19, wherein the method further comprises: The second cycle routing is to route the holes similar to the through holes.

21. A high density interconnect via chain test board, characterized by, The high-density interconnection hole chain test board is prepared by the method of any one of claims 1 to 20.

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