HDI plate glue filling method

Abstract

The invention discloses a glue filling method for an HDI (High Density Interconnection) board, which comprises the following steps: calculating the total volume of inner holes of two preset adjacent laminates and the void volume of circuit layers close to each other, further calculating the necessary glue filling volume and necessary glue filling weight between the two preset adjacent laminates, and according to the length and width sizes of the laminates, calculating the necessary glue filling volume and necessary glue filling weight between the two preset adjacent laminates. Judging whether the theoretical glue filling weight of prepregs with the same size can fill two preset adjacent laminates or not, if the theoretical glue filling weight of the prepregs with the same size meets the use condition, selecting a prepreg glue filling method for glue filling, and if the theoretical glue filling weight of the prepregs with the same size does not meet the use condition, selecting a resin hole filling glue filling method for glue filling; therefore, which mode is used for filling glue into the HDI board can be judged in advance, and a corresponding proper glue filling method is adopted in a targeted manner according to a judgment result, so that the product quality of the circuit board is improved.

Description

Technical Field

[0001] The invention relates to the field of circuit board production, and in particular to a HDI board glue filling method. Background Art

[0002] High-density interconnect board, referred to as HDI board, is a kind of circuit board, which is formed by laminating multiple layers. The layers connect different circuit layers through the conductive hole walls of the inner holes. During the production process, the layers need to be filled with glue to fill the etched gaps between the inner holes and the circuit layers to achieve the performance required by the design. The existing HDI board filling can be filled with resin plugging or semi-cured sheet glue. The resin plugging is filled in a similar way to silk screen printing, and the semi-cured sheet filling is sandwiched between two predetermined adjacent layers. During the layer lamination step, the resin in the semi-cured sheet flows out to fill the gaps between the inner holes and the circuit layer. At present, the cost of semi-cured sheet filling is lower than that of resin plugging, but not all HDI boards can be filled with semi-cured sheets. During production, production personnel are prone to abnormal filling when using semi-cured sheets, which affects the product quality of the circuit board. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for filling glue on an HDI board, which can improve the product quality of the circuit board.

[0004] According to an embodiment of the present invention, the HDI board glue filling method includes the following steps: obtaining parameters of each layer board: the board surface of the layer board is provided with a circuit layer and a plurality of inner holes, and the parameters of the layer board include the length A of the layer board and the width B of the layer board; calculating the necessary glue filling weight and the theoretical glue filling weight: calculating and obtaining the circuit layer gap volume V1 on the side where two predetermined adjacent layer boards are close to each other, calculating and obtaining the total volume V2 of the inner holes of the two predetermined adjacent layer boards, calculating the necessary glue filling weight Y1=(V1+V2)*ρ between the two predetermined adjacent layer boards, wherein ρ is the resin density, and calculating the theoretical glue filling weight Y2=N*A*B*L*G, wherein N is the number of prepregs, L is the resin fluidity of the prepregs, and G is the resin weight per unit area of ​​the prepregs; glue weight judgment and glue filling: if Y1≤Y2, the prepreg glue filling method is used to fill the prepregs between the two predetermined adjacent layer boards, and if Y1>Y2, the resin plugging glue filling method is used to fill the prepregs between the two predetermined adjacent layer boards.

[0005] The HDI board filling method according to the embodiment of the present invention has at least the following beneficial effects: by calculating the total volume of the inner holes of two predetermined adjacent layer boards and the void volume of the circuit layer on the side close to each other, the necessary filling volume and necessary filling weight between the two predetermined adjacent layer boards are calculated, and according to the length and width dimensions of the layer boards, it is judged whether the theoretical filling weight of the semi-cured sheet of the same size can fill the predetermined two adjacent layer boards, when the use conditions are met, the semi-cured sheet filling method is selected for filling, and when the use conditions are not met, the resin plugging method is selected for filling, so that it can be judged in advance which method is used to fill the HDI board, and the corresponding appropriate filling method is used in a targeted manner according to the judgment result, thereby improving the product quality of the circuit board.

[0006] According to some embodiments of the present invention, one of the predetermined adjacent layer boards is defined as an upper layer board, and the other layer board is defined as a lower layer board, and the parameters of the layer boards also include: a residual copper rate C1 of the upper layer board close to the lower layer board, a copper thickness E1 of the upper layer board close to the lower layer board, a residual copper rate C2 of the lower layer board close to the upper layer board, a copper thickness E2 of the lower layer board close to the upper layer board, a hole diameter D of the inner hole, a hole depth H of the inner hole, the number M of the inner holes, a thickness F of the layer board, and a hole distance T between any two adjacent inner holes.

[0007] According to some embodiments of the present invention, the step of calculating the necessary glue filling weight and the theoretical glue filling weight includes: the circuit layer void volume V1 = A*B*E1*(1-C1)+A*B*E2*(1-C2).

[0008] According to some embodiments of the present invention, in the step of calculating the necessary filling weight and the theoretical filling weight, the total volume of the inner hole V2 = π * D 2＊ H*M / 4.

[0009] According to some embodiments of the present invention, before the step of calculating the necessary glue filling weight and the theoretical glue filling weight, the step of preliminarily judging whether the parameters are within a predetermined range is also included: if the parameters of the layer board are within the predetermined range, the steps of calculating the necessary glue filling weight and the theoretical glue filling weight, as well as the glue weight judgment and glue filling steps are continued; if the parameters of the layer board exceed the predetermined range, the steps of calculating the necessary glue filling weight and the theoretical glue filling weight, as well as the glue weight judgment and glue filling steps are not performed, and the predetermined two adjacent layer boards are directly filled with resin plugging holes.

[0010] According to some embodiments of the present invention, the parameters of the layer plate also include a plate thickness F, and the predetermined range is F≤0.75 mm.

[0011] According to some embodiments of the present invention, the parameters of the layer plate further include a hole distance T between any two adjacent inner holes, and the predetermined range is T≥0.7 mm.

[0012] According to some embodiments of the present invention, the parameters of the layer plate further include a hole diameter D, and the predetermined range is D≤0.25 mm.

[0013] According to some embodiments of the present invention, the parameters of the layer plate further include a hole depth H and a hole diameter D, and a predetermined range of the depth-to-diameter ratio H / D is H / D≤3.

[0014] According to some embodiments of the present invention, in the step of calculating the necessary glue filling weight and the theoretical glue filling weight, the number of the prepreg sheets satisfies N≤3.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 A schematic diagram of a process of a method for filling glue on an HDI board according to an embodiment of the present invention;

[0018] Figure 2 It is a schematic cross-sectional view of two predetermined adjacent layer boards according to an embodiment of the present invention.

[0019] Reference numerals:

[0020] Layer board 100, circuit layer 110, inner hole 120; DETAILED DESCRIPTION

[0021] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0022] In the description of the present invention, it should be understood that descriptions involving orientation, such as orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0023] In the description of the present invention, "a plurality" means more than two. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0024] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0025] Reference Figure 1 , is a method for filling glue on an HDI board according to an embodiment of the present invention, comprising the following steps:

[0026] S10: Obtaining parameters of each layer board: a board surface of the layer board is provided with a circuit layer and a plurality of inner holes, and the parameters of the layer board include a length A of the layer board and a width B of the layer board;

[0027] S30: Calculate the necessary glue filling weight and theoretical glue filling weight: calculate the gap volume V1 of the circuit layer on the side where two predetermined adjacent layers are close to each other, calculate the total volume V2 of the inner holes of the two predetermined adjacent layers, calculate the necessary glue filling weight Y1=(V1+V2)*ρ between the two predetermined adjacent layers, where ρ is the resin density, and calculate the theoretical glue filling weight Y2=N*A*B*L*G, where N is the number of prepregs, L is the resin fluidity of the prepreg, and G is the resin weight per unit area of ​​the prepreg;

[0028] S40: Glue weight judgment and glue filling: if Y1≤Y2, the space between two adjacent layers is filled with glue using a prepreg glue filling method; if Y1>Y2, the space between two adjacent layers is filled with glue using a resin plugging glue filling method.

[0029] By calculating the total volume of the inner holes of the two predetermined adjacent layer boards and the void volume of the circuit layer on the side close to each other, the necessary filling volume and necessary filling weight between the two predetermined adjacent layer boards are calculated, and according to the length and width of the layer boards, it is judged whether the theoretical filling weight of the semi-cured sheet of the same size can fill the predetermined two adjacent layer boards. When the use conditions are met, the semi-cured sheet filling method is used for filling. When the use conditions are not met, the resin plug filling method is used for filling. In this way, it is possible to pre-judge which method to use for filling the HDI board, and adopt the corresponding appropriate filling method according to the judgment result, thereby improving the product quality of the circuit board.

[0030] Reference Figure 2, which is a cross-sectional schematic diagram of two adjacent layers. Define one of the predetermined adjacent layers as the upper layer, and the other layer as the lower layer. The parameters of the layers also include: the residual copper rate C1 on the side of the upper layer close to the lower layer, the copper thickness E1 on the side of the upper layer close to the lower layer, the residual copper rate C2 on the side of the lower layer close to the upper layer, the copper thickness E2 on the side of the lower layer close to the upper layer, the hole diameter D of the inner hole, the hole depth H of the inner hole, the number of inner holes M, the thickness F of the layer, and the hole distance T between any two adjacent inner holes. By obtaining multiple parameters of the layer at one time, it is convenient to calculate the necessary glue filling weight and the theoretical glue filling weight in the subsequent process, and the process is relatively simplified. There is no need to repeatedly measure the parameters, which improves production efficiency.

[0031] Specifically, the residual copper rate C1 of the upper board near the lower board can be calculated by measuring the residual copper area S1 of the upper board near the lower board, and by C1=S1 / (A*B); similarly, the residual copper rate C2 of the lower board near the upper board can be calculated by measuring the residual copper area S2 of the lower board near the upper board, and by C2=S2 / (A*B);

[0032] Specifically, the copper thickness E1 of the upper board near the lower board is equivalent to the circuit layer thickness of the upper board near the lower board; similarly, the copper thickness E2 of the lower board near the upper board is equivalent to the circuit layer thickness of the lower board near the upper board.

[0033] In the step of calculating the necessary fill weight and theoretical fill weight, the circuit layer void volume V1 = A*B*E1*(1-C1)+A*B*E2*(1-C2). The circuit layer void volume is calculated by calculation, and the result is relatively accurate compared to other physical direct measurement methods.

[0034] In the calculation of the necessary filling weight and theoretical filling weight, the total volume of the inner hole V2 = π * D 2＊ H*M / 4. The total volume of the inner pores is calculated by calculation, and the result is relatively accurate compared with other physical direct measurement methods.

[0035] It should be understood that the number of inner holes M refers to the total number of inner holes of two predetermined adjacent layers. Usually, the diameters D of the inner holes of the layers are basically the same, and the thicknesses F of the layers are basically the same. The inner holes of the layers are through holes, and the inner holes penetrate to the two opposite sides of the corresponding layers, so that the hole depths H of the inner holes in the corresponding layers are basically the same. Therefore, the above formula can be directly used to quickly obtain the total volume of the inner holes V2. There is no need to calculate the volume of each inner hole separately and then add them up to obtain the total volume of the inner holes, which greatly improves production efficiency.

[0036] Specifically, the resin density is usually ρ = 1.51 g / cm 3 .

[0037] Before the step of calculating the necessary glue filling weight and the theoretical glue filling weight in S30, it also includes the step of preliminarily judging whether the parameters meet the predetermined range: if the parameters of the layer board are within the predetermined range, the steps of calculating the necessary glue filling weight and the theoretical glue filling weight, as well as the glue weight judgment and glue filling steps are continued; if the parameters of the layer board exceed the predetermined range, the steps of calculating the necessary glue filling weight and the theoretical glue filling weight, as well as the glue weight judgment and glue filling steps are not performed, and the two adjacent layer boards are directly filled with resin plug holes. After obtaining the parameters of the layer board, a preliminary judgment step is used to quickly judge whether the parameters of the layer board meet the predetermined conditions. Only when they are fully met, the calculation step is continued. If they are not fully met, the resin plug hole filling method is directly used for filling, thereby saving unnecessary calculation steps, and the parameter judgment is relatively simple, so that the efficiency of filling can be significantly improved, and the appropriateness of the selection of the two filling methods can be improved.

[0038] In the embodiment, the predetermined range of the plate thickness F is F≤0.75mm. If the plate thickness F of the layer plate is too large, the flowing resin of the prepreg will not be able to fill the inner hole during the lamination process, and the resin will be completely solidified when the flowing resin does not fill the inner hole. Therefore, through experiments, it is found that in the case of the predetermined plate thickness F range, the prepreg filling method can be used to fill the inner hole.

[0039] Table 1 below is a test table of prepreg filling for different thickness layers. It can be seen from Table 1 that when the plate thickness F exceeds 0.75mm, the inner hole is not fully filled.

[0040] Table 1: Effect of board thickness on filler.

[0041]

[0042] In the embodiment, the predetermined range of the hole distance T is T≥0.7mm. If the hole distance T is too small, the amount of flowing resin required per unit area is too large, and the amount of flowing resin provided by the prepreg is limited, which may fail to meet the amount of flowing resin required by the inner hole, resulting in insufficient filling of the inner hole. Therefore, through experiments, it is found that in the case of the predetermined range of the hole distance T, the inner hole can only be filled by using the prepreg filling method.

[0043] The following table shows the test table of prepreg filling for different hole spacing layers. It can be seen from Table 2 that when the hole spacing T is less than 0.7mm, the inner hole is not filled.

[0044] Table 2: Effect of hole spacing on glue filling.

[0045]

[0046] Specifically, the hole distance T refers to the center distance between two different inner holes on the same layer.

[0047] In the embodiment, the predetermined range of the aperture D is D≤0.25 mm. If the aperture D is too large, the amount of flowing resin required per unit area is too large, and the amount of flowing resin provided by the prepreg is limited, which may fail to meet the amount of flowing resin required by the inner hole, resulting in insufficient filling of the inner hole. Therefore, through experiments, it is found that in the case of the predetermined range of the aperture D, the inner hole can only be filled by using the prepreg filling method.

[0048] The following table shows the test table of prepreg filling for different hole diameter layers. It can be seen from Table 3 that when the hole diameter D is greater than 0.25mm, the inner hole is not filled.

[0049] Table 3: Effect of pore size on fill.

[0050]

[0051] In the embodiment, the predetermined range of the depth-to-diameter ratio H / D is H / D≤3. If the depth-to-diameter ratio of the inner hole is too large, the pressing time is insufficient for the flowing resin to completely fill the inner hole, and the flowing resin has already been cured, resulting in a situation where the inner hole is not fully filled with glue. Therefore, through experiments, it is found that within the predetermined range of the depth-to-diameter ratio H / D, the inner hole can only be filled with glue by using the prepreg filling method.

[0052] The following table shows the test table of prepreg filling for different depth-to-diameter ratio layers. It can be seen from Table 4 that when the depth-to-diameter ratio H / D is greater than 3, the inner hole is not filled.

[0053] Table 4: Effect of depth-to-diameter ratio on fill.

[0054]

[0055] In the embodiment, the predetermined ranges of the residual copper rate C1 and the residual copper rate C2 are C1 ≥ 5% and C2 ≥ 5%. If the residual copper rate is too small, the method of filling the prepreg will result in insufficient filling due to insufficient amount of flow resin provided by the prepreg, resulting in voids in the layer board, which is likely to cause the problem of board explosion in the subsequent production process, affecting the reliability of the HDI board. Therefore, through experiments, it is found that within the predetermined range of the aspect ratio H / D, the prepreg filling method is used to fill the layer board so that the layer board can be fully filled.

[0056] The following table shows the test table of prepreg filling for laminates with different residual copper rates. As can be seen from Table 5, when the residual copper rate C1 is less than 5%, the inner hole is not filled. Similarly, when the residual copper rate C2 is less than 5%, the inner hole will also be not filled.

[0057] Table 5: Effect of residual copper rate on glue filling.

[0058] Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 <![CDATA[Copper residue rate C1]]> 2％ 3％ 4％ 5％ 6％ 7％ result There is a hole There is a hole There is a hole No holes No holes No holes

[0059] In the embodiment, in the step of calculating the necessary glue filling weight and the theoretical glue filling weight, the number of prepregs satisfies N≤3. If the method of prepreg filling is adopted, the number of prepregs is usually no more than three. If the number of prepregs is too many, there is a risk of slippage of the press plate during the lamination process, and the uniformity of the lamination force at various locations of the laminate is affected. Therefore, using three or less prepregs can reduce the risk of abnormal lamination of the HDI board and improve the lamination effect.

[0060] It should be understood that the prepregs can be prepregs of different specifications on the market, and different prepregs have different resin contents, resin fluidity, dielectric thickness, etc., and different resin weights per unit area. Those skilled in the art can make specific configurations according to actual needs.

[0061] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0062] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for filling a HDI board with glue, characterized in that: include: Obtaining parameters of each layer board: the board surface of the layer board is provided with a circuit layer and a plurality of inner holes, and the parameters of the layer board include the length A of the layer board and the width B of the layer board; Calculate the necessary glue filling weight and theoretical glue filling weight: calculate the circuit layer gap volume V1 on the side where the two predetermined adjacent layer boards are close to each other, calculate the total volume V2 of the inner holes of the two predetermined adjacent layer boards, calculate the necessary glue filling weight Y1=(V1+V2)*ρ between the two predetermined adjacent layer boards, where ρ is the resin density, and calculate the theoretical glue filling weight Y2=N*A*B*L*G, where N is the number of prepregs, L is the resin fluidity of the prepregs, and G is the resin weight per unit area of ​​the prepregs; Glue weight judgment and glue filling: If Y1≤Y2, the space between the two adjacent layers is filled with glue using the prepreg glue filling method. If Y1>Y 2， Then, a resin plugging method is used to fill the gap between two adjacent layer boards.

2. The HDI board glue filling method according to claim 1, characterized in that: It is defined that one of the predetermined adjacent layers is an upper layer, and the other layer is a lower layer. The parameters of the layers also include: a residual copper rate C1 of the upper layer close to the lower layer, a copper thickness E1 of the upper layer close to the lower layer, a residual copper rate C2 of the lower layer close to the upper layer, a copper thickness E2 of the lower layer close to the upper layer, a hole diameter D of the inner hole, a hole depth H of the inner hole, the number M of the inner holes, a thickness F of the layer, and a hole distance T between any two adjacent inner holes.

3. The HDI board glue filling method according to claim 2, characterized in that: The step of calculating the necessary glue filling weight and the theoretical glue filling weight includes: the circuit layer void volume V1 = A*B*E1*(1-C1)+A*B*E2*(1-C2).

4. The HDI board glue filling method according to claim 2, characterized in that: The steps of calculating the necessary filling weight and the theoretical filling weight include: the total volume of the inner hole V2 = π*D 2* H*M / 4.

5. The HDI board glue filling method according to claim 1, characterized in that: Before calculating the necessary glue filling weight and the theoretical glue filling weight, the step of preliminarily judging whether the parameters are within a predetermined range is also included: if the parameters of the layer board are within the predetermined range, the steps of calculating the necessary glue filling weight and the theoretical glue filling weight, as well as the glue weight judgment and glue filling steps are continued; if the parameters of the layer board exceed the predetermined range, the steps of calculating the necessary glue filling weight and the theoretical glue filling weight, as well as the glue weight judgment and glue filling steps are not performed, and the two adjacent layer boards are directly filled with glue by resin plugging.

6. The HDI board glue filling method according to claim 5, characterized in that: The parameters of the layer plate also include the plate thickness F, and the predetermined range is F≤0.75 mm.

7. The HDI board glue filling method according to claim 5, characterized in that: The parameters of the layer plate also include a hole distance T between any two adjacent inner holes, and the predetermined range is T≥0.7 mm.

8. The HDI board glue filling method according to claim 5, characterized in that: The parameters of the layer plate also include a hole diameter D, and the predetermined range is D≤0.25 mm.

9. The HDI board glue filling method according to claim 5, characterized in that: The parameters of the layer plate also include a hole depth H and a hole diameter D, and a predetermined range of the depth-to-diameter ratio H / D is H / D≤3.

10. The HDI board glue filling method according to claim 1, characterized in that: In the step of calculating the necessary glue filling weight and the theoretical glue filling weight, the number of the prepreg sheets satisfies N≤3.

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