Manufacturing method of printed circuit board resin plug hole and circuit board

Abstract

The invention relates to a manufacturing method of a printed circuit board resin plug hole and a circuit board. According to the technical scheme, the method comprises the steps that all back drilling holes in each back drilling face of the circuit board to be machined are divided into dense holes and non-dense holes; all the dense holes of each back drilling surface are evenly divided into two groups which are staggered in sequence, and a first dense hole group and a second dense hole group corresponding to each back drilling surface are obtained; the first dense hole sets of the same back drilling face are plugged, and the second dense hole sets, the non-dense holes and the through holes of the same back drilling face are plugged; performing post-curing and grinding on the circuit board to be processed after hole plugging; according to the method, it can be ensured that all the back drilling holes have sufficient ink feeding amount, and the problems that the back drilling holes are not full in hole plugging, empty and the like are solved.

Description

Technical Field

[0001] The invention relates to the technical field of circuit board manufacturing, and more specifically, to a method for manufacturing a resin plug hole of a printed circuit board and a circuit board. Background Art

[0002] As printed circuit boards are increasingly developing towards ultra-high aspect ratios and high-density back-drilling hole spacing, for back-drilling holes with high aspect ratios, such as PCB thickness ≥5mm, back-drilling depth ≧4.0mm, and back-drilling hole spacing H≤0.8mm, due to the small hole spacing, high hole density, and the fixed amount of ink under the scraper during the ink screen printing process, the back-drilling holes will have insufficient ink, and the holes are prone to incomplete plugging. If the back-drilling holes of the high aspect ratio resin plug holes are plugged twice or more, it is extremely easy for the back-drilling holes to have plugging bubbles, plugging holes and other defects.

[0003] The existing method of plugging holes with resins of high aspect ratio can be found in the invention patent of Chinese patent application number CN201110101403.1, which degasses the resin to reduce the viscosity of the resin to ensure that the high aspect ratio board can be plugged through with one cut. In practical applications, for high aspect ratio resin plugging holes with close hole spacing, due to the large back-drilling depth and small hole distance, the more holes there are in the area, the more ink is required. Therefore, each time the hole is plugged, the ink in the back-drilled hole cannot be evenly distributed, resulting in serious bubbles and fault-like voids when plugging, which seriously affects the product quality. Therefore, there is still room for improvement. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for manufacturing a resin plug hole of a printed circuit board and a circuit board to solve the above technical problems.

[0005] In a first aspect, the present invention provides a method for manufacturing a resin plug hole of a printed circuit board and a circuit board, comprising: Dividing all back-drilled holes on each back-drilled surface of the circuit board to be processed into dense holes and non-dense holes; Divide all dense holes on each back-drilled surface into two groups that are staggered in sequence, to obtain a first dense hole group and a second dense hole group corresponding to each back-drilled surface; The first dense hole group on the same back-drilled surface is plugged, and the second dense hole group, non-dense holes and through holes on the same back-drilled surface are plugged; The circuit board to be processed is post-cured and ground after the vias are plugged.

[0006] Specifically, all the back-drilled holes on the circuit board to be processed are first divided, and the back-drilled holes whose spacing with any adjacent back-drilled holes is less than or equal to the first preset distance are defined as dense holes, and the back-drilled holes whose distance with all adjacent back-drilled holes is greater than the first preset distance are defined as non-dense holes. Then, all the dense holes corresponding to each back-drilled surface are divided into two groups arranged alternately in sequence, so as to obtain the first dense hole group and the second dense hole group corresponding to each back-drilled surface; by dividing the dense holes into two groups arranged alternately in sequence, any dense hole and the dense hole adjacent to it do not belong to the same dense hole group. Then, according to the dense hole distribution of the two back-drilled surfaces of the circuit board to be processed, the two back-drilled surfaces are plugged respectively. For example, if there are dense holes on one back-drilled surface of the circuit board to be processed, and there are no dense holes on the other back-drilled surface, at this time, the first dense hole group of the back-drilled surface with dense holes is plugged first, and then the second dense hole group, non-dense holes and through holes are plugged, and finally the non-dense holes and through holes of the other back-drilled surface are plugged, and at the same time, the holes that have been plugged on one back-drilled surface are plugged, so that the plugging of the circuit board to be processed can be completed. Finally, the plugged circuit board to be processed is post-cured, and the completely post-cured circuit board to be processed is resin-polished, thereby completing the resin hole plugging process of the circuit board to be processed.

[0007] The present invention divides the back-drilled holes on each back-drilled surface of the circuit board to be processed, and divides the dense holes into two mutually staggered groups. When plugging the holes in the circuit board to be processed, the first dense hole group is plugged first, and then the second dense hole group, the non-dense holes and the through holes are plugged. By plugging the first dense hole group and the second dense hole group respectively, it can be ensured that each dense hole has a sufficient amount of ink, thereby solving the problems of incomplete plugging and voids of back-drilled holes with a high aspect ratio and a small back-drilling hole pitch.

[0008] Optionally, dividing all back-drilled holes on each back-drilled surface of the circuit board to be processed into dense holes and non-dense holes includes: Obtaining the spacing between all adjacent back-drilled holes in each back-drilled surface of the circuit board to be processed; The back-drilled holes of each back-drilled surface are divided according to the spacing to obtain dense holes and non-dense holes corresponding to each back-drilled surface.

[0009] Specifically, the spacing between all back-drilled holes on the two back-drilled surfaces is determined according to the PCB design information, and the spacing between each back-drilled hole and the adjacent back-drilled hole is compared with the first preset distance, and the back-drilled holes whose spacing with any adjacent back-drilled hole is less than or equal to the first preset distance are defined as dense holes, and the back-drilled holes whose spacing with all adjacent back-drilled holes is greater than the first preset distance are defined as non-dense holes. The first preset distance is set by the operator according to actual conditions.

[0010] Optionally, the step of dividing all dense holes of each back-drilled surface into two groups that are staggered in sequence to obtain a first dense hole group and a second dense hole group corresponding to each back-drilled surface includes: A dense hole adjacent to a through hole, a non-dense hole or a circuit board boundary in each back-drilled surface is used as a starting hole, and non-adjacent dense holes are regularly and alternately selected with the starting hole as the starting point to form a first dense hole group, and the remaining dense holes are used as a second dense hole group.

[0011] Specifically, a dense hole adjacent to a through hole, a non-dense hole or a boundary of a circuit board to be processed in any back-drilled surface is used as a starting hole, and non-adjacent dense holes are selected in a regular and staggered manner to form a first dense hole group that is staggered with each other, and the remaining dense holes are used as a second dense hole group, so that the adjacent dense holes of each dense hole in the first dense hole group and the second dense hole group are in another dense hole group.

[0012] Optionally, plugging the first dense hole group on the same back-drilled surface, and plugging the second dense hole group, non-dense holes and through holes on the same back-drilled surface, includes: plugging a first dense hole group on a back-drilled surface, and plugging a second dense hole group, non-dense holes and through holes on the same back-drilled surface; The first dense hole group of another back-drilled surface is plugged, and the second dense hole group, non-dense holes and through holes of the same back-drilled surface are plugged.

[0013] Specifically, when the resin plugging is performed on the circuit board to be processed, the dense holes in the two back-drilled surfaces of the circuit board to be processed are first allocated according to the situation. If there are dense holes on both back-drilled surfaces of the circuit board to be processed, one of the back-drilled surfaces is selected to start plugging holes. The first dense hole group of the back-drilled surface is plugged first, and then the second dense hole group, non-dense holes and through holes of the back-drilled surface are plugged to ensure that all dense holes in the first dense hole group and the second dense hole group have sufficient ink. Then the other back-drilled surface is plugged. After the first dense hole group in the other back-drilled surface is plugged, the second dense hole group, non-dense holes and through holes of the back-drilled surface are plugged, and all the plugged back-drilled holes of one back-drilled surface are plugged, and the plugging of the circuit board to be processed can be completed. If there is dense holes on only one back-drilled surface of the circuit board to be processed, the first dense hole group of the back-drilled surface with dense holes is plugged first, and then the second dense hole group, non-dense holes and through holes of the back-drilled surface are plugged, and finally the non-dense holes and through holes of the back-drilled surface without dense holes are plugged, and the back-drilled holes corresponding to the back-drilled surface with dense holes are plugged, and the plugging of the circuit board to be processed can be completed.

[0014] Optionally, plugging a first dense hole group on a back-drilled surface and plugging a second dense hole group, non-dense holes and through holes on the same back-drilled surface includes: A first aluminum sheet and a second aluminum sheet are prefabricated to match a back-drilled surface; the first aluminum sheet is provided with a first lower oil hole to match a first dense hole group on a back-drilled surface; the second aluminum sheet is provided with a second lower oil hole to match a second dense hole group, non-dense holes and through holes on the same back-drilled surface; The first aluminum sheet and the second aluminum sheet are sequentially placed on a back-drilled surface, and the first dense hole group, the second dense hole group, the non-dense holes and the through holes on the back-drilled surface are plugged respectively.

[0015] Specifically, before plugging the dense holes on a back-drilled surface, a corresponding first aluminum sheet needs to be made according to the position of the first dense hole group on the back-drilled surface, and a first oil hole corresponding to the first dense hole group is opened on the first aluminum sheet. A corresponding second aluminum sheet is made according to the position of the second dense hole group, non-dense holes and through holes on the back-drilled surface, and a second oil hole corresponding to the second dense hole group, non-dense holes and through holes is opened on the second aluminum sheet. When plugging the back-drilled surface with resin, the first aluminum sheet is first placed on the back-drilled surface, and oil is applied through the first oil hole on the first aluminum sheet to plug only the first dense hole group. Then, the second aluminum sheet is placed on the back-drilled surface, and oil is applied through the second oil hole on the second aluminum sheet to plug the second dense hole group, non-dense holes and through holes. Since the second aluminum sheet does not have an oil hole corresponding to the first dense hole group, the ink in the first dense hole assembly will not be affected when the second dense hole group is oiled, thereby avoiding bubbles or fault-like voids caused by multiple plugging of the first dense hole group.

[0016] Optionally, placing the first aluminum sheet and the second aluminum sheet on a back-drilled surface in sequence, and plugging the back-drilled first dense hole group, the second dense hole group, the non-dense holes and the through holes respectively, comprises: Placing a first aluminum sheet on the corresponding back-drilled surface, and filling oil through a first oil filling hole on the first aluminum sheet to plug a first dense hole group on the back-drilled surface; A second aluminum sheet is placed on the same back-drilled surface, and oil is applied from the second oiling hole on the second aluminum sheet to plug the second dense hole group, non-dense holes and through holes on the back-drilled surface.

[0017] Specifically, when the back-drilled surface is plugged with resin, the first aluminum sheet is first placed on the back-drilled surface, and oil is applied through the first oil-applying hole on the first aluminum sheet to achieve plugging of only the first dense hole group. Subsequently, the second aluminum sheet is placed on the back-drilled surface, and oil is applied through the second oil-applying hole on the second aluminum sheet to achieve plugging of the second dense hole group, non-dense holes, and through holes. Since the second aluminum sheet does not have an oil-applying hole corresponding to the first dense hole group, the ink in the first dense hole assembly will not be affected when the second dense hole group is plugged with oil, thereby avoiding bubbles or fault-like voids caused by multiple plugging of the first dense hole group.

[0018] Optionally, plugging the first dense hole group of another back-drilled surface and plugging the second dense hole group, non-dense holes and through holes of the same back-drilled surface includes: A third aluminum sheet and a fourth aluminum sheet are prefabricated to correspond to the other back-drilled surface; the third aluminum sheet is provided with a third lower oil hole corresponding to the first dense hole group of the other back-drilled surface; the fourth aluminum sheet is provided with a fourth lower oil hole corresponding to the second dense hole group, the non-dense holes, the through holes, and the plug holes of the back-drilled holes of the back-drilled surface; The third aluminum sheet and the fourth aluminum sheet are sequentially placed on the other back-drilled surface, and the first dense hole group, the second dense hole group, the non-dense holes, the through holes, and the back-drilled holes of the other back-drilled surface are plugged respectively.

[0019] When there are dense holes on both back-drilled surfaces of the circuit board to be processed, it is necessary to make aluminum sheets according to both back-drilled surfaces of the circuit board to be processed. Specifically, before plugging the dense holes on the other back-drilled surface, it is necessary to make a corresponding third aluminum sheet according to the position of the first dense hole group on the back-drilled surface, and the third aluminum sheet is provided with a third lower oil hole corresponding to the first dense hole group. According to the position of the second dense hole group, non-dense holes, through holes, and the plugging holes of the back-drilled holes of the back-drilled surface, a corresponding fourth aluminum sheet is made, and the fourth aluminum sheet is provided with a fourth lower oil hole corresponding to the second dense hole group, non-dense holes, through holes, and the back-drilled holes of the back-drilled surface. When plugging the back-drilled surface with resin, first place the third aluminum sheet on the back-drilled surface, and apply oil through the third lower oil hole on the third aluminum sheet to achieve plugging of only the first dense hole group on the back-drilled surface. Then, the fourth aluminum sheet is placed on the back-drilled surface, and oil is applied through the fourth oil-applying hole on the fourth aluminum sheet to plug the second dense hole group, the non-dense holes and through holes, and the back-drilled holes on the back-drilled surface. Since the fourth aluminum sheet does not have an oil-applying hole corresponding to the first dense hole group on the back-drilled surface, the ink in the first dense hole group will not be affected when the second dense hole group is oiled, thereby avoiding bubbles or fault-like voids caused by multiple plugging of the first dense hole group.

[0020] Optionally, the step of sequentially placing the third aluminum sheet and the fourth aluminum sheet on another back-drilled surface, and plugging the first dense hole group, the second dense hole group, the non-dense holes, the through holes, and the back-drilled holes of the other back-drilled surface, respectively, comprises: Placing a third aluminum sheet on the corresponding back-drilled surface, and applying oil from the third oil-applying hole of the third aluminum sheet to plug the first dense hole group of the back-drilled hole; A fourth aluminum sheet is placed on the same back-drilled surface, and oil is applied from the fourth oil hole of the fourth aluminum sheet to plug the second dense hole group, non-dense holes, through holes and the back-drilled holes of the back-drilled surface.

[0021] Specifically, when the back-drilled surface is plugged with resin, the third aluminum sheet is first placed on the back-drilled surface, and oil is applied through the third oil-applying hole on the third aluminum sheet to achieve plugging of only the first dense hole group on the back-drilled surface. Subsequently, the fourth aluminum sheet is placed on the back-drilled surface, and oil is applied through the fourth oil-applying hole on the fourth aluminum sheet to achieve plugging of the second dense hole group, non-dense holes and through holes, and the back-drilled holes of a back-drilled surface. Since the fourth aluminum sheet does not have an oil-applying hole corresponding to the first dense hole group on the back-drilled surface, the ink in the first dense hole assembly will not be affected when the second dense hole group is oiled, thereby avoiding bubbles or fault-like voids caused by multiple plugging of the first dense hole group.

[0022] Optionally, plugging the first dense hole group of another back-drilled surface and plugging the second dense hole group, non-dense holes and through holes of the same back-drilled surface further includes: A depth control pad is provided on a back drill surface to isolate the vacuum zone from the dense holes; a groove corresponding to the position of the dense holes on the back drill surface is provided on the depth control pad; and a through groove corresponding to the position of the non-dense holes and through holes on the back drill surface is provided on the depth control pad.

[0023] Specifically, after completing the plugging of the first dense hole group and the second dense hole group of a back-drilled surface, when plugging the first dense hole group, the second dense hole group, the non-dense holes, and the back-drilled holes of another back-drilled surface, in order to prevent the dense holes of the back-drilled surface from being connected to the vacuum, the dense hole positions of the back-drilled surface on the depth control pad are not drilled through, so a groove corresponding to the dense hole positions of the back-drilled surface is opened on the depth control pad, which can make way for the dense hole positions of the back-drilled surface to avoid the depth control pad from contacting the resin ink at the dense hole positions of the back-drilled surface. The non-dense holes and through-hole positions on the depth control pad corresponding to the back-drilled surface are drilled through, and when plugging the non-dense holes and through-holes of the back-drilled surface, vacuum plugging can be performed to ensure the plugging effect of the non-dense holes and through-holes. At this time, in the vacuum plugging machine, since the positions of dense holes are isolated by the controlled depth pad, when plugging the dense holes on the back drilled surface, the positions of the dense holes on the back drilled surface will not be affected by the vacuum, so it is not easy to have problems such as depression, explosion and other hole damage on the back drilled surface.

[0024] In a second aspect, the present invention further provides a circuit board, which is manufactured by applying the above-mentioned method for manufacturing a printed circuit board resin plugging hole.

[0025] Specifically, the circuit board manufactured based on the above-mentioned method for manufacturing a printed circuit board resin plugging hole has sufficient resin ink filled in the back-drilled holes with a small back-drilled hole distance to avoid serious bubbles and fault-like voids in the back-drilled holes, thereby improving product quality.

[0026] In summary, the present invention has the following beneficial effects: By dividing the back-drilled holes on each back-drilled surface of the circuit board to be processed, and dividing the dense holes into two interlaced groups, when plugging the holes in the circuit board to be processed, the first dense hole group is plugged first, and then the second dense hole group, non-dense holes and through holes are plugged. By plugging the first dense hole group and the second dense hole group respectively, it can be ensured that each dense hole has sufficient ink volume, thereby solving the problems of incomplete plugging and voids of back-drilled holes with a high aspect ratio and a small back-drilling hole spacing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a flow chart of the method of the present invention; Figure 2 It is a schematic diagram of the plugging process of the first embodiment of the present invention; Figure 3 It is a schematic diagram of the depth control pad in the second embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. Several embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0030] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0031] Embodiment 1 This embodiment provides a method for manufacturing a resin plug hole of a printed circuit board, such as Figure 1 and Figure 2 As shown, including: Dividing all back-drilled holes on each back-drilled surface of the circuit board to be processed into dense holes and non-dense holes; Divide all dense holes on each back-drilled surface into two groups that are staggered in sequence, to obtain a first dense hole group and a second dense hole group corresponding to each back-drilled surface; The first dense hole group on the same back-drilled surface is plugged, and the second dense hole group, non-dense holes and through holes on the same back-drilled surface are plugged; The circuit board to be processed is post-cured and ground after the vias are plugged.

[0032] Specifically, all the back-drilled holes on the circuit board to be processed are first divided, and the back-drilled holes whose spacing with any adjacent back-drilled holes is less than or equal to the first preset distance are defined as dense holes, and the back-drilled holes whose distance with all adjacent back-drilled holes is greater than the first preset distance are defined as non-dense holes. Then, all the dense holes corresponding to each back-drilled surface are divided into two groups arranged alternately in sequence, so as to obtain the first dense hole group and the second dense hole group corresponding to each back-drilled surface; by dividing the dense holes into two groups arranged alternately in sequence, any dense hole and the dense hole adjacent to it do not belong to the same dense hole group. Then, according to the dense hole distribution of the two back-drilled surfaces of the circuit board to be processed, the two back-drilled surfaces are plugged respectively. For example, if there are dense holes on one back-drilled surface of the circuit board to be processed, and there are no dense holes on the other back-drilled surface, at this time, the first dense hole group of the back-drilled surface with dense holes is plugged first, and then the second dense hole group, non-dense holes and through holes are plugged, and finally the non-dense holes and through holes of the other back-drilled surface are plugged, and at the same time, the holes that have been plugged on one back-drilled surface are plugged, so that the plugging of the circuit board to be processed can be completed. Finally, the plugged circuit board to be processed is post-cured, and the fully post-cured circuit board to be processed is resin-polished, and the resin plugging process of the circuit board to be processed can be completed. In this embodiment, the first preset distance is 0.8 mm.

[0033] The present invention divides the back-drilled holes on each back-drilled surface of the circuit board to be processed, and divides the dense holes into two mutually staggered groups. When plugging the holes in the circuit board to be processed, the first dense hole group is plugged first, and then the second dense hole group, the non-dense holes and the through holes are plugged. By plugging the first dense hole group and the second dense hole group respectively, it can be ensured that each dense hole has a sufficient amount of ink, thereby solving the problems of incomplete plugging and voids of back-drilled holes with a high aspect ratio and a small back-drilling hole pitch.

[0034] Optionally, dividing all back-drilled holes on each back-drilled surface of the circuit board to be processed into dense holes and non-dense holes includes: Obtaining the spacing between all adjacent back-drilled holes in each back-drilled surface of the circuit board to be processed; The back-drilled holes of each back-drilled surface are divided according to the spacing to obtain dense holes and non-dense holes corresponding to each back-drilled surface.

[0035] Specifically, the spacing between all back-drilled holes on the two back-drilled surfaces is determined based on the PCB design information, and the spacing between each back-drilled hole and the adjacent back-drilled hole is compared with the first preset distance, and the back-drilled holes whose spacing with any adjacent back-drilled hole is less than or equal to the first preset distance are defined as dense holes, and the back-drilled holes whose spacing with all adjacent back-drilled holes is greater than the first preset distance are defined as non-dense holes. The first preset distance is set by the operator according to actual conditions. In this embodiment, the first preset distance is 0.8 mm.

[0036] Optionally, the step of dividing all dense holes of each back-drilled surface into two groups that are staggered in sequence to obtain a first dense hole group and a second dense hole group corresponding to each back-drilled surface includes: A dense hole adjacent to a through hole, a non-dense hole or a circuit board boundary in each back-drilled surface is used as a starting hole, and non-adjacent dense holes are regularly and alternately selected with the starting hole as the starting point to form a first dense hole group, and the remaining dense holes are used as a second dense hole group.

[0037] Specifically, a dense hole adjacent to a through hole, a non-dense hole or a boundary of a circuit board to be processed in any back-drilled surface is used as a starting hole, and non-adjacent dense holes are selected in a regular and staggered manner to form a first dense hole group that is staggered with each other, and the remaining dense holes are used as a second dense hole group, so that the adjacent dense holes of each dense hole in the first dense hole group and the second dense hole group are in another dense hole group.

[0038] Optionally, plugging the first dense hole group on the same back-drilled surface, and plugging the second dense hole group, non-dense holes and through holes on the same back-drilled surface, includes: plugging a first dense hole group on a back-drilled surface, and plugging a second dense hole group, non-dense holes and through holes on the same back-drilled surface; The first dense hole group of another back-drilled surface is plugged, and the second dense hole group, non-dense holes and through holes of the same back-drilled surface are plugged.

[0039] Specifically, when performing resin plugging on the circuit board to be processed, the dense holes in the two back-drilled surfaces of the circuit board to be processed are first allocated according to the conditions. If only one back-drilled surface of the circuit board to be processed has dense holes, the first dense hole group of the back-drilled surface with dense holes is plugged first, and then the second dense hole group, non-dense holes and through holes of the back-drilled surface are plugged, and finally the non-dense holes and through holes of the back-drilled surface without dense holes are plugged, and the back-drilled holes corresponding to the back-drilled surface with dense holes are plugged, and the plugging of the circuit board to be processed can be completed.

[0040] Optionally, plugging a first dense hole group on a back-drilled surface and plugging a second dense hole group, non-dense holes and through holes on the same back-drilled surface includes: A first aluminum sheet and a second aluminum sheet are prefabricated to match a back-drilled surface; the first aluminum sheet is provided with a first lower oil hole to match a first dense hole group on a back-drilled surface; the second aluminum sheet is provided with a second lower oil hole to match a second dense hole group, non-dense holes and through holes on the same back-drilled surface; The first aluminum sheet and the second aluminum sheet are sequentially placed on a back-drilled surface, and the first dense hole group, the second dense hole group, the non-dense holes and the through holes on the back-drilled surface are plugged respectively.

[0041] Specifically, before plugging the dense holes on a back-drilled surface, a corresponding first aluminum sheet needs to be made according to the position of the first dense hole group on the back-drilled surface, and a first oil hole corresponding to the first dense hole group is opened on the first aluminum sheet. A corresponding second aluminum sheet is made according to the position of the second dense hole group, non-dense holes and through holes on the back-drilled surface, and a second oil hole corresponding to the second dense hole group, non-dense holes and through holes is opened on the second aluminum sheet. When plugging the back-drilled surface with resin, the first aluminum sheet is first placed on the back-drilled surface, and oil is applied through the first oil hole on the first aluminum sheet to plug only the first dense hole group. Then, the second aluminum sheet is placed on the back-drilled surface, and oil is applied through the second oil hole on the second aluminum sheet to plug the second dense hole group, non-dense holes and through holes. Since the second aluminum sheet does not have an oil hole corresponding to the first dense hole group, the ink in the first dense hole assembly will not be affected when the second dense hole group is oiled, thereby avoiding bubbles or fault-like voids caused by multiple plugging of the first dense hole group.

[0042] Optionally, placing the first aluminum sheet and the second aluminum sheet on a back-drilled surface in sequence, and plugging the back-drilled first dense hole group, the second dense hole group, the non-dense holes and the through holes respectively, comprises: Placing a first aluminum sheet on the corresponding back-drilled surface, and filling oil through a first oil filling hole on the first aluminum sheet to plug a first dense hole group on the back-drilled surface; A second aluminum sheet is placed on the same back-drilled surface, and oil is applied from the second oiling hole on the second aluminum sheet to plug the second dense hole group, non-dense holes and through holes on the back-drilled surface.

[0043] Specifically, when the back-drilled surface is plugged with resin, the first aluminum sheet is first placed on the back-drilled surface, and oil is applied through the first oil-applying hole on the first aluminum sheet to achieve plugging of only the first dense hole group. Subsequently, the second aluminum sheet is placed on the back-drilled surface, and oil is applied through the second oil-applying hole on the second aluminum sheet to achieve plugging of the second dense hole group, non-dense holes, and through holes. Since the second aluminum sheet does not have an oil-applying hole corresponding to the first dense hole group, the ink in the first dense hole assembly will not be affected when the second dense hole group is plugged with oil, thereby avoiding bubbles or fault-like voids caused by multiple plugging of the first dense hole group.

[0044] In this embodiment, taking the case where only one back-drilled surface has dense holes as an example, when plugging holes on a PCB board, the following steps are performed in sequence: 1) Baking plate: The baking plate keeps the PCB surface temperature at about 45°C. When plugging holes, take it out of the oven and complete all the holes that need to be plugged within 10 minutes; 2) Plug hole 1: Plug the first dense hole group through the first aluminum sheet from the back drill surface, and do not plug the through holes and non-dense holes; 3) Plug hole 2: Replace the second aluminum sheet and continue to plug the second dense hole group, through holes and non-dense holes from the back drill surface; 4) Plug hole 3: Replace the aluminum sheet corresponding to the through holes and back-drilled holes on the other back-drilled surface and plug all through holes and all back-drilled holes that need to be plugged from the other back-drilled surface; 5) Post-baking: post-curing the plugged PCB board; 6) Resin grinding: The fully post-cured PCB board is subjected to resin grinding.

[0045] Embodiment 2 This embodiment provides a method for manufacturing a resin plug hole of a printed circuit board, such as Figure 1 and Figure 3 As shown, including: Dividing all back-drilled holes on each back-drilled surface of the circuit board to be processed into dense holes and non-dense holes; Divide all dense holes on each back-drilled surface into two groups that are staggered in sequence, to obtain a first dense hole group and a second dense hole group corresponding to each back-drilled surface; The first dense hole group on the same back-drilled surface is plugged, and the second dense hole group, non-dense holes and through holes on the same back-drilled surface are plugged; The circuit board to be processed is post-cured and ground after the vias are plugged.

[0046] Specifically, all the back-drilled holes on the circuit board to be processed are first divided, and the back-drilled holes whose spacing with any adjacent back-drilled holes is less than or equal to the first preset distance are defined as dense holes, and the back-drilled holes whose distance with all adjacent back-drilled holes is greater than the first preset distance are defined as non-dense holes. Then, all the dense holes corresponding to each back-drilled surface are divided into two groups arranged alternately in sequence, so as to obtain the first dense hole group and the second dense hole group corresponding to each back-drilled surface; by dividing the dense holes into two groups arranged alternately in sequence, any dense hole and the dense hole adjacent to it do not belong to the same dense hole group. Then, according to the dense hole distribution of the two back-drilled surfaces of the circuit board to be processed, the two back-drilled surfaces are plugged respectively. For example, if there are dense holes on one back-drilled surface of the circuit board to be processed, and there are no dense holes on the other back-drilled surface, at this time, the first dense hole group of the back-drilled surface with dense holes is plugged first, and then the second dense hole group, non-dense holes and through holes are plugged, and finally the non-dense holes and through holes of the other back-drilled surface are plugged, and at the same time, the holes that have been plugged on one back-drilled surface are plugged, so that the plugging of the circuit board to be processed can be completed. Finally, the plugged circuit board to be processed is post-cured, and the fully post-cured circuit board to be processed is resin-polished, and the resin plugging process of the circuit board to be processed can be completed. In this embodiment, the first preset distance is 0.8 mm.

[0047] The present invention divides the back-drilled holes on each back-drilled surface of the circuit board to be processed, and divides the dense holes into two mutually staggered groups. When plugging the holes in the circuit board to be processed, the first dense hole group is plugged first, and then the second dense hole group, the non-dense holes and the through holes are plugged. By plugging the first dense hole group and the second dense hole group respectively, it can be ensured that each dense hole has a sufficient amount of ink, thereby solving the problems of incomplete plugging and voids of back-drilled holes with a high aspect ratio and a small back-drilling hole pitch.

[0048] Optionally, dividing all back-drilled holes on each back-drilled surface of the circuit board to be processed into dense holes and non-dense holes includes: Obtaining the spacing between all adjacent back-drilled holes in each back-drilled surface of the circuit board to be processed; The back-drilled holes of each back-drilled surface are divided according to the spacing to obtain dense holes and non-dense holes corresponding to each back-drilled surface.

[0049] Specifically, the spacing between all back-drilled holes on the two back-drilled surfaces is determined based on the PCB design information, and the spacing between each back-drilled hole and the adjacent back-drilled hole is compared with the first preset distance, and the back-drilled holes whose spacing with any adjacent back-drilled hole is less than or equal to the first preset distance are defined as dense holes, and the back-drilled holes whose spacing with all adjacent back-drilled holes is greater than the first preset distance are defined as non-dense holes. The first preset distance is set by the operator according to actual conditions. In this embodiment, the first preset distance is 0.8 mm.

[0050] Optionally, the step of dividing all dense holes of each back-drilled surface into two groups that are staggered in sequence to obtain a first dense hole group and a second dense hole group corresponding to each back-drilled surface includes: A dense hole adjacent to a through hole, a non-dense hole or a circuit board boundary in each back-drilled surface is used as a starting hole, and non-adjacent dense holes are regularly and alternately selected with the starting hole as the starting point to form a first dense hole group, and the remaining dense holes are used as a second dense hole group.

[0051] Specifically, a dense hole adjacent to a through hole, a non-dense hole or a boundary of a circuit board to be processed in any back-drilled surface is used as a starting hole, and non-adjacent dense holes are selected in a regular and staggered manner to form a first dense hole group that is staggered with each other, and the remaining dense holes are used as a second dense hole group, so that the adjacent dense holes of each dense hole in the first dense hole group and the second dense hole group are in another dense hole group.

[0052] Optionally, plugging the first dense hole group on the same back-drilled surface, and plugging the second dense hole group, non-dense holes and through holes on the same back-drilled surface, includes: plugging a first dense hole group on a back-drilled surface, and plugging a second dense hole group, non-dense holes and through holes on the same back-drilled surface; The first dense hole group of another back-drilled surface is plugged, and the second dense hole group, non-dense holes and through holes of the same back-drilled surface are plugged.

[0053] Specifically, when the resin plugging is performed on the circuit board to be processed, the dense holes in the two back-drilled surfaces of the circuit board to be processed are first allocated according to the situation. If there are dense holes on both back-drilled surfaces of the circuit board to be processed, one of the back-drilled surfaces is selected to start plugging holes. The first dense hole group of the back-drilled surface is plugged first, and then the second dense hole group, non-dense holes and through holes of the back-drilled surface are plugged to ensure that all dense holes in the first dense hole group and the second dense hole group have sufficient ink. Then the other back-drilled surface is plugged. After the first dense hole group in the other back-drilled surface is plugged, the second dense hole group, non-dense holes and through holes of the back-drilled surface are plugged, and all the plugged back-drilled holes of one back-drilled surface are plugged, and the plugging of the circuit board to be processed can be completed.

[0054] Optionally, plugging a first dense hole group on a back-drilled surface and plugging a second dense hole group, non-dense holes and through holes on the same back-drilled surface includes: A first aluminum sheet and a second aluminum sheet are prefabricated to match a back-drilled surface; the first aluminum sheet is provided with a first lower oil hole to match a first dense hole group on a back-drilled surface; the second aluminum sheet is provided with a second lower oil hole to match a second dense hole group, non-dense holes and through holes on the same back-drilled surface; The first aluminum sheet and the second aluminum sheet are sequentially placed on a back-drilled surface, and the first dense hole group, the second dense hole group, the non-dense holes and the through holes on the back-drilled surface are plugged respectively.

[0055] Specifically, before plugging the dense holes on a back-drilled surface, a corresponding first aluminum sheet needs to be made according to the position of the first dense hole group on the back-drilled surface, and a first oil hole corresponding to the first dense hole group is opened on the first aluminum sheet. A corresponding second aluminum sheet is made according to the position of the second dense hole group, non-dense holes and through holes on the back-drilled surface, and a second oil hole corresponding to the second dense hole group, non-dense holes and through holes is opened on the second aluminum sheet. When plugging the back-drilled surface with resin, the first aluminum sheet is first placed on the back-drilled surface, and oil is applied through the first oil hole on the first aluminum sheet to plug only the first dense hole group. Then, the second aluminum sheet is placed on the back-drilled surface, and oil is applied through the second oil hole on the second aluminum sheet to plug the second dense hole group, non-dense holes and through holes. Since the second aluminum sheet does not have an oil hole corresponding to the first dense hole group, the ink in the first dense hole assembly will not be affected when the second dense hole group is oiled, thereby avoiding bubbles or fault-like voids caused by multiple plugging of the first dense hole group.

[0056] Optionally, placing the first aluminum sheet and the second aluminum sheet on a back-drilled surface in sequence, and plugging the back-drilled first dense hole group, the second dense hole group, the non-dense holes and the through holes respectively, comprises: Placing a first aluminum sheet on the corresponding back-drilled surface, and filling oil through a first oil filling hole on the first aluminum sheet to plug a first dense hole group on the back-drilled surface; A second aluminum sheet is placed on the same back-drilled surface, and oil is applied from the second oiling hole on the second aluminum sheet to plug the second dense hole group, non-dense holes and through holes on the back-drilled surface.

[0057] Specifically, when the back-drilled surface is plugged with resin, the first aluminum sheet is first placed on the back-drilled surface, and oil is applied through the first oil-applying hole on the first aluminum sheet to achieve plugging of only the first dense hole group. Subsequently, the second aluminum sheet is placed on the back-drilled surface, and oil is applied through the second oil-applying hole on the second aluminum sheet to achieve plugging of the second dense hole group, non-dense holes, and through holes. Since the second aluminum sheet does not have an oil-applying hole corresponding to the first dense hole group, the ink in the first dense hole assembly will not be affected when the second dense hole group is plugged with oil, thereby avoiding bubbles or fault-like voids caused by multiple plugging of the first dense hole group.

[0058] Optionally, plugging the first dense hole group of another back-drilled surface and plugging the second dense hole group, non-dense holes and through holes of the same back-drilled surface includes: A third aluminum sheet and a fourth aluminum sheet are prefabricated to correspond to the other back-drilled surface; the third aluminum sheet is provided with a third lower oil hole corresponding to the first dense hole group of the other back-drilled surface; the fourth aluminum sheet is provided with a fourth lower oil hole corresponding to the second dense hole group, the non-dense holes, the through holes, and the plug holes of the back-drilled holes of the back-drilled surface; The third aluminum sheet and the fourth aluminum sheet are sequentially placed on the other back-drilled surface, and the first dense hole group, the second dense hole group, the non-dense holes, the through holes, and the back-drilled holes of the other back-drilled surface are plugged respectively.

[0059] When there are dense holes on both back-drilled surfaces of the circuit board to be processed, it is necessary to make aluminum sheets according to both back-drilled surfaces of the circuit board to be processed. Specifically, before plugging the dense holes on the other back-drilled surface, it is necessary to make a corresponding third aluminum sheet according to the position of the first dense hole group on the back-drilled surface, and the third aluminum sheet is provided with a third lower oil hole corresponding to the first dense hole group. According to the position of the second dense hole group, non-dense holes, through holes, and the plugging holes of the back-drilled holes of the back-drilled surface, a corresponding fourth aluminum sheet is made, and the fourth aluminum sheet is provided with a fourth lower oil hole corresponding to the second dense hole group, non-dense holes, through holes, and the back-drilled holes of the back-drilled surface. When plugging the back-drilled surface with resin, first place the third aluminum sheet on the back-drilled surface, and apply oil through the third lower oil hole on the third aluminum sheet to achieve plugging of only the first dense hole group on the back-drilled surface. Then, the fourth aluminum sheet is placed on the back-drilled surface, and oil is applied through the fourth oil-applying hole on the fourth aluminum sheet to plug the second dense hole group, the non-dense holes and through holes, and the back-drilled holes on the back-drilled surface. Since the fourth aluminum sheet does not have an oil-applying hole corresponding to the first dense hole group on the back-drilled surface, the ink in the first dense hole group will not be affected when the second dense hole group is oiled, thereby avoiding bubbles or fault-like voids caused by multiple plugging of the first dense hole group.

[0060] Optionally, the step of sequentially placing the third aluminum sheet and the fourth aluminum sheet on another back-drilled surface, and plugging the first dense hole group, the second dense hole group, the non-dense holes, the through holes, and the back-drilled holes of the other back-drilled surface, respectively, comprises: Placing a third aluminum sheet on the corresponding back-drilled surface, and applying oil from the third oil-applying hole of the third aluminum sheet to plug the first dense hole group of the back-drilled hole; A fourth aluminum sheet is placed on the same back-drilled surface, and oil is applied from the fourth oil hole of the fourth aluminum sheet to plug the second dense hole group, non-dense holes, through holes and the back-drilled holes of the back-drilled surface.

[0061] Specifically, when the back-drilled surface is plugged with resin, the third aluminum sheet is first placed on the back-drilled surface, and oil is applied through the third oil-applying hole on the third aluminum sheet to achieve plugging of only the first dense hole group on the back-drilled surface. Subsequently, the fourth aluminum sheet is placed on the back-drilled surface, and oil is applied through the fourth oil-applying hole on the fourth aluminum sheet to achieve plugging of the second dense hole group, non-dense holes and through holes, and the back-drilled holes of a back-drilled surface. Since the fourth aluminum sheet does not have an oil-applying hole corresponding to the first dense hole group on the back-drilled surface, the ink in the first dense hole assembly will not be affected when the second dense hole group is oiled, thereby avoiding bubbles or fault-like voids caused by multiple plugging of the first dense hole group.

[0062] Optionally, plugging the first dense hole group of another back-drilled surface and plugging the second dense hole group, non-dense holes and through holes of the same back-drilled surface further includes: A depth control pad is provided on a back drill surface to isolate the vacuum zone from the dense holes; a groove corresponding to the position of the dense holes on the back drill surface is provided on the depth control pad; and a through groove corresponding to the position of the non-dense holes and through holes on the back drill surface is provided on the depth control pad.

[0063] Specifically, after completing the plugging of the first dense hole group and the second dense hole group of a back-drilled surface, when plugging the first dense hole group, the second dense hole group, the non-dense holes, and the back-drilled holes of another back-drilled surface, in order to prevent the dense holes of the back-drilled surface from being connected to the vacuum, the dense hole positions of the back-drilled surface on the depth control pad are not drilled through, so a groove corresponding to the dense hole positions of the back-drilled surface is opened on the depth control pad, which can make way for the dense hole positions of the back-drilled surface to avoid the depth control pad from contacting the resin ink at the dense hole positions of the back-drilled surface. The non-dense holes and through-hole positions on the depth control pad corresponding to the back-drilled surface are drilled through, and when plugging the non-dense holes and through-holes of the back-drilled surface, vacuum plugging can be performed to ensure the plugging effect of the non-dense holes and through-holes. At this time, in the vacuum plugging machine, since the positions of dense holes are isolated by the controlled depth pad, when plugging the dense holes on the back drilled surface, the positions of the dense holes on the back drilled surface will not be affected by the vacuum, so it is not easy to have problems such as depression, explosion and other hole damage on the back drilled surface.

[0064] In this embodiment, there are dense holes on both the front and back back drilling surfaces. When plugging the holes on the PCB board, the following steps are performed in sequence: 1) Baking plate: The baking plate keeps the PCB surface temperature at about 45°C. When plugging holes, take it out of the oven and complete all the holes that need to be plugged within 10 minutes; 2) Plug hole 1: Plug the first dense hole group through the first aluminum sheet from the back drill surface, and do not plug the through holes and non-dense holes; 3) Plug hole 2: Replace the second aluminum sheet and continue to plug the second dense hole group, through holes and non-dense holes from the back drill surface; 4) Plug hole 3: Replace the third aluminum sheet and plug the first dense hole group from the other back-drilled surface; 5) Plug hole 4: Replace the fourth aluminum sheet and continue to plug the second dense hole group, through holes and non-dense holes from the back drill surface; 6) Post-baking: post-curing the plugged PCB board; 7) Resin grinding: The fully post-cured PCB board is subjected to resin grinding.

[0065] Embodiment 3 This embodiment provides a circuit board, which is manufactured based on the method for manufacturing a printed circuit board resin plugging hole as described in the above embodiment 1 or embodiment 2.

[0066] Specifically, the circuit board manufactured based on the above-mentioned method for manufacturing a printed circuit board resin plugging hole has sufficient resin ink filled in the back-drilled holes with a small back-drilled hole distance to avoid serious bubbles and fault-like voids in the back-drilled holes, thereby improving product quality.

[0067] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for making a resin plug hole in a printed circuit board, characterized in that: include: Dividing all back-drilled holes on each back-drilled surface of the circuit board to be processed into dense holes and non-dense holes; Divide all dense holes on each back-drilled surface into two groups that are staggered in sequence, to obtain a first dense hole group and a second dense hole group corresponding to each back-drilled surface; The first dense hole group on the same back-drilled surface is plugged, and the second dense hole group, non-dense holes and through holes on the same back-drilled surface are plugged; The circuit board to be processed is post-cured and ground after the vias are plugged.

2. The method for making a printed circuit board resin plug hole according to claim 1, characterized in that: The method of dividing all the back-drilled holes on each back-drilled surface of the circuit board to be processed into dense holes and non-dense holes comprises: Obtaining the spacing between all adjacent back-drilled holes in each back-drilled surface of the circuit board to be processed; The back-drilled holes of each back-drilled surface are divided according to the spacing to obtain dense holes and non-dense holes corresponding to each back-drilled surface.

3. The method for manufacturing a printed circuit board resin plug hole according to claim 1, characterized in that: The method of dividing all dense holes of each back-drilled surface into two groups that are staggered in sequence to obtain a first dense hole group and a second dense hole group corresponding to each back-drilled surface includes: A dense hole adjacent to a through hole, a non-dense hole or a circuit board boundary in each back-drilled surface is used as a starting hole, and non-adjacent dense holes are regularly and alternately selected with the starting hole as the starting point to form a first dense hole group, and the remaining dense holes are used as a second dense hole group.

4. The method for manufacturing a printed circuit board resin plug hole according to claim 1, characterized in that: The method of plugging the first dense hole group on the same back-drilled surface and plugging the second dense hole group, non-dense holes and through holes on the same back-drilled surface includes: plugging a first dense hole group on a back-drilled surface, and plugging a second dense hole group, non-dense holes and through holes on the same back-drilled surface; The first dense hole group of another back-drilled surface is plugged, and the second dense hole group, non-dense holes and through holes of the same back-drilled surface are plugged.

5. The method for manufacturing a printed circuit board resin plug hole according to claim 4, characterized in that: The method of plugging a first dense hole group on a back-drilled surface and plugging a second dense hole group, non-dense holes and through holes on the same back-drilled surface comprises: A first aluminum sheet and a second aluminum sheet are prefabricated to match a back-drilled surface; the first aluminum sheet is provided with a first lower oil hole to match a first dense hole group on a back-drilled surface; the second aluminum sheet is provided with a second lower oil hole to match a second dense hole group, non-dense holes and through holes on the same back-drilled surface; The first aluminum sheet and the second aluminum sheet are sequentially placed on a back-drilled surface, and the first dense hole group, the second dense hole group, the non-dense holes and the through holes on the back-drilled surface are plugged respectively.

6. The method for manufacturing a printed circuit board resin plug hole according to claim 5, characterized in that: The method of sequentially placing the first aluminum sheet and the second aluminum sheet on a back-drilled surface and plugging the back-drilled first dense hole group, the second dense hole group, the non-dense holes and the through holes respectively comprises: Placing a first aluminum sheet on the corresponding back-drilled surface, and filling oil through a first oil filling hole on the first aluminum sheet to plug a first dense hole group on the back-drilled surface; A second aluminum sheet is placed on the same back-drilled surface, and oil is applied from the second oiling hole on the second aluminum sheet to plug the second dense hole group, non-dense holes and through holes on the back-drilled surface.

7. The method for manufacturing a printed circuit board resin plug hole according to claim 4, characterized in that: The method of plugging the first dense hole group of another back-drilled surface and plugging the second dense hole group, non-dense holes and through holes of the same back-drilled surface includes: A third aluminum sheet and a fourth aluminum sheet are prefabricated to correspond to the other back-drilled surface; the third aluminum sheet is provided with a third lower oil hole corresponding to the first dense hole group of the other back-drilled surface; the fourth aluminum sheet is provided with a fourth lower oil hole corresponding to the second dense hole group, the non-dense holes, the through holes, and the plug holes of the back-drilled holes of the back-drilled surface; The third aluminum sheet and the fourth aluminum sheet are sequentially placed on the other back-drilled surface, and the first dense hole group, the second dense hole group, the non-dense holes, the through holes, and the back-drilled holes of the other back-drilled surface are plugged respectively.

8. The method for manufacturing a printed circuit board resin plug hole according to claim 7, characterized in that: The method sequentially places the third aluminum sheet and the fourth aluminum sheet on the other back-drilled surface, and plugs the first dense hole group, the second dense hole group, the non-dense holes, the through holes, and the back-drilled holes of the other back-drilled surface, respectively, including: Placing a third aluminum sheet on the corresponding back-drilled surface, and applying oil from the third oil-applying hole of the third aluminum sheet to plug the first dense hole group of the back-drilled hole; A fourth aluminum sheet is placed on the same back-drilled surface, and oil is applied from the fourth oil hole of the fourth aluminum sheet to plug the second dense hole group, non-dense holes, through holes and the back-drilled holes of the back-drilled surface.

9. The method for manufacturing a printed circuit board resin plug hole according to claim 4, characterized in that: The plugging of the first dense hole group of another back-drilled surface and the plugging of the second dense hole group, the non-dense holes and the through holes of the same back-drilled surface also include: A depth control pad is provided on a back drill surface to isolate the vacuum zone from the dense holes; a groove corresponding to the position of the dense holes on the back drill surface is provided on the depth control pad; and a through groove corresponding to the position of the non-dense holes and through holes on the back drill surface is provided on the depth control pad.

10. A circuit board, characterized in that: The printed circuit board is manufactured by using a method for manufacturing resin plug holes according to any one of claims 1 to 9.

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