A multilayer plate structure convenient for measuring expansion and contraction

Abstract

The utility model discloses a multilayer board structure that is convenient for measuring expansion and contraction, including a stacking layer, wherein the stacking layer is formed by stacking M core boards; the non-functional area of ​​the core board is provided with at least two test areas, wherein the test areas are provided with a first pad and a second pad; M is an integer greater than 1; the first pads in the M core boards do not overlap in a direction perpendicular to the plane where the core board is located; the second pads in the M core boards overlap in a direction perpendicular to the plane where the core board is located. The present application sets the position of the test area and assists in the design of the first pad and the second pad, and can simultaneously measure the expansion and contraction of the entire multilayer board and each layer of the core board in different directions, thereby improving the diversity and accuracy of the measurement of the expansion and contraction of the multilayer board structure.

Description

Technical Field

[0001] The utility model relates to the technical field of PCB processing, in particular to a multilayer board structure that is convenient for measuring expansion and contraction. Background Art

[0002] The circuit board is made of multiple inner core boards pressed together. The inner core board refers to the core board after the inner layer graphics are completed. Due to the different thicknesses, support structures (glass cloth), and core copper foil thicknesses of the inner core boards, the changes in the core board graphics during pressing are inconsistent, resulting in the vertical misalignment of the inner layer graphics, affecting the production quality of the circuit board. The change in the core board graphics refers to the size of the core board graphics, also known as expansion and contraction.

[0003] In order to solve the problem of inner layer pattern deviation of circuit boards, it is necessary to monitor the size change of inner layer patterns. Patent CN106852030B discloses a method for determining the inner layer compensation coefficient of PCB, which provides a theory of expansion and contraction measurement, but does not define the design method of the measurement target pattern.

[0004] For the graphic design that monitors the size changes of the inner layer graphics of the circuit board, the traditional design in the industry is to provide a set of target graphics at the midpoints of the long and short sides of the product graphics. The defect of this design is that it can only measure the distance changes between the midpoints of the long and short sides, which is basically applicable to products with symmetrical graphics. In actual production, the design of product graphics is changeable, and asymmetric structural graphics are the norm. When faced with the monitoring requirements of products with asymmetric structural graphics, the data error range obtained by the traditional design in the industry is relatively large, resulting in amplified deviations in the later process during production. Utility Model Content

[0005] In view of this, the present application aims to solve the problems in the related art to at least a certain extent. One of the purposes of the present application is to provide a multi-layer board structure that is convenient for measuring the expansion and contraction. By setting the position of the test area and assisting the design of the first pad and the second pad, the expansion and contraction of the entire multi-layer board and each layer of the core board in different directions can be measured simultaneously, thereby improving the diversity and accuracy of the expansion and contraction measurement of the multi-layer board structure.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solution: a multilayer board structure that is convenient for measuring the expansion and contraction amount, comprising a stacking layer, wherein the stacking layer is formed by stacking M core boards; at least two test areas are provided in the non-functional area of ​​the core board, and a first pad and a second pad are provided in the test area; M is an integer greater than 1;

[0007] The first welding pads of the M core boards do not overlap in a direction perpendicular to the plane where the core boards are located;

[0008] The second pads in the M core boards overlap in a direction perpendicular to the plane where the core boards are located.

[0009] Furthermore, the stacked layer is located in a measuring device, and the measuring device is capable of monitoring the coordinates of the first pad and the second pad in each core board before and after lamination of the stacked layer.

[0010] Furthermore, a functional area is provided in the middle of the core board, a non-functional area is provided outside the functional area, the minimum distance between the test area and the functional area is greater than 2 mm; the minimum distance between the test area and the edge of the core board is greater than 2 mm.

[0011] Furthermore, there are four test areas, the stacking layer is a rectangular parallelepiped structure, and the four test areas are respectively located at four corners of the stacking layer.

[0012] Furthermore, the first pad is a cylindrical structure, and the four first pads in the four test areas in the same core board are symmetrically distributed relative to the center point of the core board.

[0013] Furthermore, the diameter of the first pad is 2 mm, and the center distance between the first pads between adjacent core boards in the same test area is 3 mm.

[0014] Furthermore, the projections of the first pads in the M core boards in the same test area on the same core board are distributed in a matrix.

[0015] Furthermore, the second pad is a cylindrical structure, and the four second pads in the four test areas in the same core board are symmetrically distributed relative to the center point of the core board.

[0016] Furthermore, the diameter of the second pad is 1 mm.

[0017] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art: the position of the test area in each core board in the present application is the same, and the test areas can be two or four. The position change of the first pad in two adjacent test areas can feedback the expansion and contraction of the corresponding layer of the core board in the direction of the test area connection line; the position change of the second pad in two adjacent test areas can feedback the expansion and contraction of the entire multilayer board in the direction of the test area connection line; when calculating the expansion and contraction, the standard value of the change of each layer of the core board and the entire multilayer board during the pressing process is available, and by measuring the actual change of the pad, the ratio of the actual distance to the standard change value is the expansion and contraction of a layer of the core board and the entire multilayer board during the pressing process; when calculating the expansion and contraction of the entire multilayer board, the average position or average coordinate of the M second pads in the same test area can be used as the actual distance; by setting the position of the test area and assisting the design of the first pad and the second pad, the present application can simultaneously measure the expansion and contraction of the entire multilayer board and each layer of the core board in different directions, thereby improving the diversity and accuracy of the measurement of the expansion and contraction of the multilayer board structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0020] In the attached figure:

[0021] Figure 1 It is a schematic diagram of the structure of the test area in the core board;

[0022] Figure 2 is a schematic diagram of the structure of the first pad in the test area;

[0023] Figure 3 is a schematic diagram of the structure of the second pad in the test area;

[0024] Figure 4 This is a schematic diagram showing the test results of the first pad in Example 2;

[0025] Figure 5 This is a schematic diagram showing the test results of the second pad in Example 2.

[0026] Reference numerals:

[0027] 11. core board; 12. test area; 13. first pad; 131. first pad of the first layer core board; 132. first pad of the second layer core board; 133. first pad of the third layer core board; 14. second pad. DETAILED DESCRIPTION

[0028] In order to have a clearer understanding of the technical features, purposes and effects of the present application, the specific implementation methods of the present application are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the mechanism or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present application.

[0029] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0030] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, mechanisms, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0031] Example 1

[0032] like Figure 1-Figure 4 As shown, the present application proposes a multilayer board structure that is convenient for measuring expansion and contraction, including a stacked layer, wherein the stacked layer is formed by stacking M core boards 11; at least two test areas 12 are provided in a non-functional area of ​​the core board 11, and a first pad 13 and a second pad 14 are provided in the test area 12; M is an integer greater than 1;

[0033] The first welding pads 13 in the M core boards 11 do not overlap in a direction perpendicular to the plane where the core board 11 is located;

[0034] The second pads 14 in the M core boards 11 overlap in a direction perpendicular to the plane where the core board 11 is located.

[0035] In the present application, the position of the test area 12 in each core board 11 is the same, and the test area 12 can be two or four. The position change of the first pad 13 in two adjacent test areas 12 can feedback the expansion and contraction of the corresponding layer of the core board in the direction of the test area 12 connection line; the position change of the second pad 14 in two adjacent test areas 12 can feedback the expansion and contraction of the entire multilayer board in the direction of the test area 12 connection line; when calculating the expansion and contraction, the standard value of the change of each layer of the core board and the entire multilayer board during the pressing process is available, and by measuring the actual change of the pad, the ratio of the actual distance to the standard change value is the expansion and contraction of a layer of the core board and the entire multilayer board during the pressing process; when calculating the expansion and contraction of the entire multilayer board, the average position or average coordinate of the M second pads 14 in the same test area 12 can be used as the actual distance; by setting the position of the test area 12, the present application assists the design of the first pad 13 and the second pad 14, and can simultaneously measure the expansion and contraction of the entire multilayer board and each layer of the core board in different directions, thereby improving the diversity and accuracy of the measurement of the expansion and contraction of the multilayer board structure.

[0036] As a specific embodiment, when there are two test areas 12, the two test areas 12 can be located at the two ends of the long side, the two ends of the short side, or the two ends of the diagonal of the core board 11. This embodiment is explained by taking the two test areas 12 located at the two ends of the diagonal as an example. When the two test areas 12 are located at the two ends of the diagonal of the core board 11, assuming that the stacking layer is a 3-layer structure, two test areas 12 are set on the diagonal of each layer of the core board, and a first solder pad 13 and a second solder pad 14 are set in the test area 12 of each core board 11, wherein the first solder pads 13 in the same test area 12 in the three core boards 11 do not overlap, and the second solder pads 14 in the same test area 12 in the three core boards 11 overlap.

[0037] Before lamination, the distance between the two first pads 13 in each core board 11 can be obtained, and after lamination, the distance between the two first pads 13 in each core board 11 can also be obtained; since the material of the core board 11 is already qualified and the lamination conditions are known, under the lamination conditions, the size change of the core board 11 has a certain standard value, which is also referred to as the standard change value in this application. Among them, after lamination, the ratio of the actual distance between the two first pads 13 in the same core board 11 to the standard change value is the expansion and contraction of the core board 11 in the diagonal direction. By the same token, after lamination, the actual distance between the second pads 14 in each core board 11 is known, and the average actual distance of the second pads 14 in the three core boards 11 can be calculated; the standard change value of the overall multi-layer board is determined, and the ratio between the average actual distance and the standard change value is the expansion and contraction of the entire multi-layer board structure in the diagonal direction.

[0038] Example 2

[0039] like Figure 1-Figure 4As shown, the present application provides a multilayer board structure that is convenient for measuring expansion and contraction, including a stacking layer, wherein the stacking layer is formed by stacking M core boards 11; the non-functional area of ​​the core board 11 is provided with four test areas 12, and the test area 12 is provided with a first soldering pad 13 and a second soldering pad 14; M is an integer greater than 1; the stacking layer is a rectangular parallelepiped structure, and the four test areas 12 are respectively located at the four corners of the stacking layer. A functional area is provided in the middle of the core board 11 of the present application, and a non-functional area is provided on the outside of the functional area. The minimum distance between the test area 12 and the functional area is greater than 2 mm; the minimum distance between the test area 12 and the edge of the core board 11 is greater than 2 mm. The test area 12 maintains a certain distance from the edge of the core board 11 and the functional area in order to avoid affecting the functional area, or to avoid the test area 12 stepping out of the edge of the core board 11 due to the expansion and contraction and layer deviation after pressing.

[0040] The first pads 13 in the M core boards 11 do not overlap in a direction perpendicular to the plane of the core board 11; the first pads 13 are cylindrical structures, and the four first pads 13 in the four test areas 12 in the same core board 11 are symmetrically distributed relative to the center point of the core board 11. The diameter of the first pad 13 is 2 mm, and the center distance of the first pads 13 between adjacent core boards 11 in the same test area 12 is 3 mm. The projections of the first pads 13 in the M core boards 11 in the same test area 12 in the same core board 11 are distributed in a matrix.

[0041] As a specific embodiment, Figure 2As shown, in the present application, the first pads 13 can be staggered and distributed in sequence along the long side direction of the core board 11. Taking the test area 12 in the upper left corner of the core board 11 as an example, the first pad 131 of the first core board is located at the upper left side, the first pad 132 of the second core board is located at the lower left side, the first pad 133 of the third core board is located at the upper right side, and the first pad 13 of the fourth core board is located at the lower right side, and so on. Correspondingly, in the test area 12 in the upper right corner of the core board 11, the first pad 131 of the first core board is located at the upper right side, the first pad 132 of the second core board is located at the lower right side, the first pad 133 of the third core board is located at the upper left side, and the first pad 13 of the fourth core board is located at the lower left side, and so on. Correspondingly, in the test area 12 at the lower left corner of the core board 11, the first solder pad 131 of the first core board is located at the lower left side, the first solder pad 132 of the second core board is located at the upper left side, the first solder pad 133 of the third core board is located at the lower right side, and the first solder pad 13 of the fourth core board is located at the upper right side, and so on. Correspondingly, in the test area 12 at the lower right corner of the core board 11, the first solder pad 131 of the first core board is located at the lower right side, the first solder pad 132 of the second core board is located at the upper right side, the first solder pad 133 of the third core board is located at the lower left side, and the first solder pad 13 of the fourth core board is located at the lower left side, and so on. It is necessary to ensure that the four first solder pads 13 in the four test areas 12 in the same core board 11 are symmetrically distributed relative to the center point of the core board 11.

[0042] like Figure 3 As shown, the second pads 14 in the M core boards 11 overlap in a direction perpendicular to the plane of the core board 11. The second pad 14 is a cylindrical structure, and the four second pads 14 in the four test areas 12 in the same core board 11 are symmetrically distributed relative to the center point of the core board 11. The diameter of the second pad 14 is 1 mm.

[0043] In the present application, the second pad 14 is located in the test area 12 at a position that does not overlap with the first pad 13 .

[0044] The present application also includes a measuring device, in which the stacked layer is located, and the measuring device can monitor the coordinates of the first pads 13 and the second pads 14 in each core board 11 before and after lamination of the stacked layer. The measuring device can monitor the coordinates of each first pad 13 and the second pad 14 in real time, and can obtain the coordinate values ​​of the first pad 13 and the second pad 14 in real time before and after lamination, so as to facilitate the calculation of the distance between any two pads.

[0045] The position of the test area 12 and the position settings of the first pad 13 and the second pad 14 in the present application can calculate the expansion and contraction of the long side, the short side and the diagonal line of the core board 11. The specific calculation method is as follows:

[0046] (1) The calculation of the expansion and contraction of the entire multilayer board is performed using the change in the coordinate value of the second pad 14:

[0047] Before lamination, the coordinate values ​​of all the second pads 14 are obtained. Since the second pads 14 overlap in a direction perpendicular to the plane of the core board 11, that is, the x-axis and y-axis coordinates of the second pads 14 in the same test area 12 are the same, the distance between the two second pads 14 in the long side direction, the short side direction, and the diagonal direction can be calculated.

[0048] After lamination, the coordinate values ​​of all the second pads 14 are obtained. If the second pads 14 in the same test area 12 in the M core boards 11 do not overlap, their average coordinate value can be calculated to obtain the actual distance between the two second pads 14 in the long side direction, short side direction and diagonal direction after lamination.

[0049] Since the material of the core board 11 is already qualified and the pressing conditions are known, under the pressing conditions, the dimensional change of the core board 11 has a certain standard value, which is also referred to as the standard change value in this application. The amount of expansion and contraction in the long side direction is equal to the ratio of the actual distance between the two second pads 14 in the long side direction after pressing to the standard change value. The amount of expansion and contraction in the short side direction is equal to the ratio of the actual distance between the two second pads 14 in the short side direction after pressing to the standard change value. The amount of expansion and contraction in the diagonal direction is equal to the ratio of the actual distance between the two second pads 14 in the diagonal direction after pressing to the standard change value.

[0050] like Figure 5 As shown, the measuring device of the present application can display the position and coordinates of the second pad 14 in each layer of the core board, and can also calculate the expansion and contraction of the multilayer board in the long side, short side, and diagonal hexagonal dimensions based on the coordinate change and the pre-stored standard change value.

[0051] (2) For the calculation of the expansion and contraction of the single-layer core board, the coordinate value change of the first pad 13 is used for calculation:

[0052] Before lamination, the coordinate values ​​of all the first pads 13 in the corresponding core board are obtained, and the distance between two first pads 13 in the long side direction, short side direction and diagonal direction of the core board 11 can be calculated.

[0053] After lamination, the coordinate values ​​of all first pads 13 in the corresponding core board are obtained, and the actual distance between two first pads 13 in the long side direction, short side direction and diagonal direction after lamination is calculated.

[0054] Since the material of the core board 11 is already qualified and the pressing conditions are known, under the pressing conditions, the dimensional change of the core board 11 has a certain standard value, which is also referred to as the standard change value in this application. The amount of expansion and contraction in the long side direction is equal to the ratio of the actual distance between the two first pads 13 in the long side direction after pressing to the standard change value. The amount of expansion and contraction in the short side direction is equal to the ratio of the actual distance between the two first pads 13 in the short side direction after pressing to the standard change value. The amount of expansion and contraction in the diagonal direction is equal to the ratio of the actual distance between the two first pads 13 in the diagonal direction after pressing to the standard change value.

[0055] like Figure 4 As shown, the measuring device of the present application can display the position and coordinates of the second pad 14 in each layer of the core board, and can also calculate the expansion and contraction of each layer of the core board in the long side, short side, and diagonal hexagonal dimensions based on the coordinate change and the pre-stored standard change value.

[0056] The present application has more dimensional data after being measured by a measuring device, which is more representative. Compared with traditional designs, it is more consistent with the actual board size and more accurate. It can also be displayed graphically through software to visualize the product size change characteristics.

[0057] It can be understood that the above embodiments only express the preferred implementation methods of the present application, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present application; it should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, the above-mentioned technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the present application; therefore, all equivalent changes and modifications made to the scope of the claims of the present application should belong to the scope covered by the claims of the present application.

Claims

1. A multilayer board structure that is convenient for measuring expansion and contraction, characterized in that: The stacking layer comprises M core boards stacked together; the non-functional area of ​​the core board is provided with at least two test areas, and the test areas are provided with a first pad and a second pad; M is an integer greater than 1; The first welding pads of the M core boards do not overlap in a direction perpendicular to the plane where the core boards are located; The second pads in the M core boards overlap in a direction perpendicular to the plane where the core boards are located.

2. A multilayer board structure for measuring expansion and contraction according to claim 1, characterized in that: The stacked layers are located in a measuring device capable of monitoring the coordinates of the first pads and the second pads in each core board before and after lamination of the stacked layers.

3. A multilayer board structure for measuring expansion and contraction according to claim 1, characterized in that: A functional area is arranged in the middle of the core board, a non-functional area is arranged outside the functional area, the minimum distance between the test area and the functional area is greater than 2 mm; the minimum distance between the test area and the edge of the core board is greater than 2 mm.

4. A multilayer board structure for measuring expansion and contraction according to claim 1, characterized in that: There are four test areas, and the stacking layer is a rectangular parallelepiped structure. The four test areas are respectively located at four corners of the stacking layer.

5. A multilayer board structure for measuring expansion and contraction according to claim 4, characterized in that: The first pad is a cylindrical structure, and the four first pads in the four test areas in the same core board are symmetrically distributed relative to the center point of the core board.

6. A multilayer board structure for measuring expansion and contraction according to claim 5, characterized in that: The diameter of the first pad is 2 mm, and the center distance between the first pads between adjacent core boards in the same test area is 3 mm.

7. A multilayer board structure for measuring expansion and contraction according to claim 6, characterized in that: The projections of the first pads in the M core boards in the same test area on the same core board are distributed in a matrix.

8. A multilayer board structure for measuring expansion and contraction according to claim 4, characterized in that: The second pad is a cylindrical structure, and the four second pads in the four test areas in the same core board are symmetrically distributed relative to the center point of the core board.

9. A multilayer board structure for measuring expansion and contraction according to claim 8, characterized in that: The diameter of the second pad is 1 mm.

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