Selective resin hole plugging method and circuit board
By preparing dry film baffles and pores on the circuit board, the problem that the resin plug-in process is difficult to prevent resin from entering the plug-in holes on high-pore density circuit boards is achieved, and the effect of simplifying the processing process and reducing costs is achieved. .
Patent Information
- Application Number
- CN202411713497.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-02-11
AI Technical Summary
The existing resin plug-in process is difficult to effectively prevent resin from entering the second metallized hole without plug-in on circuit boards with high hole density, resulting in complex processing processes and high cost.
By making the first and second metallization holes on the substrate and covering the dry film on the surface of the substrate, photolithography is performed to prepare the dry film baffle and the air pores, ensuring that the resin can only enter the first metallization hole.
Effectively prevent resin from entering the second metallized hole without plug holes, simplifies the circuit board processing process, reduces costs, and is suitable for circuit board processing with higher hole density.
Smart Images
Figure CN119421331A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of circuit board processing, and in particular to a selective resin plugging method and a circuit board. Background Art
[0002] The resin plugging process is widely used in today's circuit board manufacturing process. However, due to the influence of equipment capabilities, the distance between the holes that need to be plugged and the holes that do not need to be plugged is limited. For circuit boards that exceed the distance limit, a secondary drilling process needs to be designed, that is, the holes that need to be plugged with resin are drilled for the first time, and then the holes that do not need to be plugged with resin are drilled for the second time. This increases a lot of process costs. In addition, due to the need for two electroplatings due to the secondary drilling, the copper thickness often exceeds the design requirements of the circuit board, which leads to the need to design a copper reduction process, further increasing the process cost of circuit board processing. Summary of the invention
[0003] The present application provides a selective resin plugging method and a circuit board, which can effectively prevent resin from entering into a second metallized hole that does not need plugging, and can be applicable to the processing of circuit boards with higher hole density.
[0004] The present application provides a selective resin plugging method, comprising:
[0005] Making a first metallized hole and a second metallized hole on the substrate;
[0006] Coating a dry film on the surface of the substrate;
[0007] Performing photolithography on the dry film to obtain a dry film blocking piece opposite to the second metallized hole, and making an air hole connected to the second metallized hole on the dry film blocking piece, so that the inner diameter D1 of the air hole is smaller than the inner diameter D2 of the second metallized hole;
[0008] Filling the first metallization hole with resin;
[0009] The dry film blocking sheet is removed.
[0010] In some possible implementations, the outer diameter D3 of the dry film stopper is 6 mil to 20 mil larger than the inner diameter D2 of the second metallized hole.
[0011] In some possible implementations, the inner diameter D1 of the pore is set to be 15 mil to 25 mil.
[0012] In some possible implementations, the photolithography of the dry film to obtain a dry film blocking piece opposite to the second metallized hole, and forming an air hole connected to the second metallized hole on the dry film blocking piece, so that the inner diameter D1 of the air hole is smaller than the inner diameter D2 of the second metallized hole, includes:
[0013] Exposing the dry film so that the unexposed area covers the position relative to the first metallized hole and the position of the air hole;
[0014] The dry film is developed to obtain the dry film blocking sheet, and the pores are formed on the dry film blocking sheet.
[0015] In some possible implementations, before filling the first metallization hole with resin, the selective resin plugging method further includes:
[0016] The dry film baffle is dried.
[0017] In some possible implementations, drying the dry film baffle includes:
[0018] The substrate with the dry film barrier sheet attached thereto is placed in a baking oven, and the temperature of the baking oven is maintained at 150° C. to 180° C., and the baking is performed for 1.5 hours to 2.5 hours.
[0019] In some possible implementations, filling the first metallization hole with resin includes:
[0020] Vacuuming the space where the substrate to which the dry film baffle is attached is located;
[0021] The first metallization hole is filled with resin.
[0022] In some possible implementations, the step of making a first metallized hole and a second metallized hole on the substrate includes:
[0023] providing a substrate;
[0024] Processing a first through hole at a first preset position of the substrate, and processing a second through hole at a second preset position;
[0025] The first through hole and the second through hole are metallized.
[0026] In some possible implementations, after filling the first metallization hole with resin, the selective resin plugging method further includes:
[0027] The resin is polished to remove the resin outside the first metallization hole.
[0028] In addition, the present application also provides a circuit board, which is processed by the selective resin plugging method provided in the above embodiments.
[0029] Beneficial effects of the present application: The selective resin plugging method provided by the present application covers a dry film baffle at the position of the second metallized hole that does not need plugging, and opens air holes on the dry film baffle. In the process of filling the resin, the dry film baffle can be prevented from being broken due to vacuuming, and the dry film baffle can also effectively prevent the resin from entering the second metallized hole. Even if the resin flow rate is large, the resin can be effectively prevented from entering the second metallized hole. Therefore, it can be applied to the processing process of circuit boards with higher hole density, meet high-demand processing needs, and simplify the processing flow of circuit boards. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0031] Figure 1 A schematic diagram of the process of selective resin plugging method in some embodiments is shown;
[0032] Figure 2 shows a schematic structural diagram of a substrate in some embodiments;
[0033] Figure 3 A schematic diagram of the structure of making metallized holes in a substrate in some embodiments is shown;
[0034] Figure 4 A schematic diagram of the manufacturing process of metallized holes in some embodiments is shown;
[0035] Figure 5 A schematic diagram of the structure of a dry film on a substrate in some embodiments is shown;
[0036] Figure 6 A schematic diagram of a process of photolithography of a dry film in some embodiments is shown;
[0037] Figure 7 A schematic diagram of the structure of a dry film baffle and a substrate in some embodiments is shown;
[0038] Figure 8 A schematic diagram of the structure of a substrate during the resin filling process in some embodiments is shown;
[0039] Fig. 9 A schematic diagram of the substrate structure after plugging holes in some embodiments is shown.
[0040] Description of main component symbols:
[0041] 100 - substrate; 101 - first surface; 102 - second surface; 110 - first metallized hole; 111 - first through hole; 120 - second metallized hole; 121 - second through hole;
[0042] 200-dry film; 210-air hole; 220-dry film baffle;
[0043] 300-resin. DETAILED DESCRIPTION
[0044] The embodiments of the present application are described in detail below, and examples of the embodiments 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 application, and cannot be understood as limiting the present application.
[0045] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element 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 application.
[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0047] In this application, 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0048] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0049] like Figure 1 As shown, a selective resin plugging method is provided in the embodiment, which can be used to fill a part of the metallized holes on the circuit board with resin 300 during the processing of the circuit board.
[0050] like Figures 1 to 3 , Fig. 9 As shown, in some embodiments, the selective resin plugging method includes:
[0051] S100 , manufacturing a first metallized hole 110 and a second metallized hole 120 on a substrate 100 .
[0052] In some embodiments, the first metallized hole 110 may be a hole that needs to be filled with resin 300, and the second metallized hole 120 may be a hole that does not need to be filled with resin 300. The first metallized hole 110 and the second metallized hole 120 may both be round holes or slot holes.
[0053] like Figures 2 to 4 As shown, in some embodiments, step S100 may include:
[0054] S110 , providing a substrate 100 .
[0055] S120 , processing the first through hole 111 at the first preset position of the substrate 100 , and processing the second through hole 121 at the second preset position.
[0056] In some embodiments, the first through hole 111 and the second through hole 121 can be processed on the substrate 100 by laser processing or mechanical processing. The first through hole 111 can be located at a first preset position, and the second through hole 121 can be located at a second preset position. The first through hole 111 and the second through hole 121 can both be circular holes or slot structures with opening structures at both ends. It can be understood that the first through hole 111 and the second through hole 121 can be provided with one or more.
[0057] In the embodiment of the present application, all through holes on the circuit board can be processed through one through hole processing operation, including through holes that need to be filled with resin and through holes that do not need to be filled with resin, without the need for batch processing, thereby avoiding the need for copper reduction operations due to the copper plating thickness on the substrate 100 exceeding the requirement. In addition, the process flow of the circuit board can be saved and the processing efficiency of the circuit board can be improved.
[0058] S130 , performing metallization processing on the first through hole 111 and the second through hole 121 .
[0059] In some embodiments, a layer of copper may be deposited on the inner wall of the first through hole 111 and the inner wall of the second through hole 121 by a copper deposition process to achieve preliminary metallization of the inner wall of the first through hole 111 and the inner wall of the second through hole 121, so that the inner wall of the first through hole 111 and the inner wall of the second through hole 121 may be subsequently electroplated with copper. Afterwards, copper may be electroplated at the desired position on the surface of the substrate 100 and the inner wall of the first through hole 111 and the inner wall of the second through hole 121 by an electroplating process, so that the inner wall of the first through hole 111 and the inner wall of the second through hole 121 are attached with a desired thickness of copper plating, thereby achieving metallization of the first through hole 111 and the second through hole 121. In some embodiments, the inner diameter of the first metallized hole 110 and the inner diameter D2 of the second metallized hole 120 may both be set to, wherein the diameter of the circular hole may be greater than or equal to 2 mm, and the width of the slot may be greater than or equal to 1 mm.
[0060] S200 , coating the surface of the substrate 100 with a dry film 200 .
[0061] like Figure 2 , Figure 3 and Figure 5 As shown, the substrate 100 may include a first surface 101 and a second surface 102 disposed opposite to each other. In an embodiment, a layer of dry film 200 may be coated on the first surface 101 and the second surface 102 of the substrate 100, respectively. In some embodiments, the dry film 200 (i.e., a photosensitive film layer) may be pressed on the first surface 101 and the second surface 102 of the substrate 100, respectively, by a dry film laminator. In an embodiment, the dry film 200 may cover the first metallized hole 110 and the second metallized hole 120 at the same time.
[0062] S300 , photolithography is performed on the dry film 200 to obtain a dry film stopper 220 opposite to the second metallization hole 120 , and air holes 210 are formed on the dry film stopper 220 .
[0063] like Figure 7 As shown, in some embodiments, the inner diameter D1 of the air hole 210 may be significantly smaller than the inner diameter D2 of the second metallized hole 120. In an embodiment, when the second metallized hole 120 is a slot, the inner diameter D2 of the second metallized hole 120 may refer to the width of the second metallized hole 120.
[0064] like Figures 5 to 8 As shown, in some embodiments, step S300 may include:
[0065] S310 , exposing the dry film 200 , and making the unexposed area include the relative position to the first metallized hole 110 and the position where the air hole 210 is located.
[0066] In some embodiments, a mask plate with a patterned design may be applied to the side of the dry film 200 facing away from the substrate 100. Then, the dry film 200 is subjected to an irradiation exposure process to transfer the patterned design on the mask plate to the dry film 200. The unexposed area on the dry film 200 may include a position opposite to the first metallized hole 110 and a position where the air hole 210 is located. The exposed area may undergo a cross-linking polymerization reaction after irradiation.
[0067] S320 , developing the dry film 200 to obtain a dry film blocking piece 220 , and forming air holes 210 on the dry film blocking piece 220 .
[0068] In some embodiments, the substrate 100 covered with the dry film 200 can be placed in a developer for development. The unexposed area of the dry film 200 can be dissolved in a weakly alkaline developer because no cross-linking polymerization reaction occurs, and the relative position of the substrate 100 is exposed, that is, the position on the substrate 100 that is opposite to the unexposed area is exposed. Thus, a dry film stopper 220 attached to the surface of the substrate 100 can be prepared. The dry film stopper 220 can be arranged opposite to the second metallized hole 120 and mounted on the substrate 100 around the second metallized hole 120. The weakly alkaline developer can be a sodium bicarbonate solution.
[0069] It is understandable that the dry film stopper 220 can seal the opening structure of the second metallized hole 120, and can prevent the resin 300 from entering the second metallized hole 120 during the subsequent process of filling the resin 300. In addition, the pore 210 can be formed on the dry film stopper 220 and communicate with the second metallized hole 120.
[0070] In some embodiments, the inner diameter D1 of the pore 210 can be set to 15 mil to 25 mil, which can prevent the resin 300 from entering the second metallized hole 120 through the pore 210 while achieving air permeability. For example, in some embodiments, the inner diameter D1 of the pore 210 can be set to 15 mil, 16.5 mil, 18 mil, 19.2 mil, 20 mil, 20.5 mil, 21 mil, 22.5 mil, 23.2 mil, 23.8 mil, 24 mil, 24.6 mil, 25 mil or any other value between 15 mil and 25 mil.
[0071] In some embodiments, the outer diameter D3 of the dry film blocking piece 220 may be 6 mil to 20 mil larger than the inner diameter D2 of the second metallized hole 120. On the one hand, it can ensure that the dry film blocking piece 220 can be stably mounted on the substrate 100 around the second metallized hole 120, reducing the possibility of the dry film blocking piece 220 being separated from the substrate 100 at will. On the other hand, it can also minimize the occupied area of the dry film blocking piece 220 on the substrate 100, so that the selective resin plugging method provided in the present application can be applied to the processing of circuit boards with denser through-hole distribution, and fill the resin 300. For example, in some embodiments, the outer diameter D3 of the dry film stopper 220 may be 6 mil, 6.5 mil, 7.2 mil, 8 mil, 10.5 mil, 11 mil, 12.5 mil, 13 mil, 14.5 mil, 15 mil, 15.5 mil, 16 mil, 17.5 mil, 18.8 mil, 20 mil, or any other value between 6 mil and 20 mil, greater than the inner diameter D2 of the second metallized hole 120.
[0072] like Figure 1 and Figure 7 As shown, in some embodiments, the selective resin plugging method further includes:
[0073] S400, drying the dry film blocking sheet 220.
[0074] In some embodiments, the substrate 100 covered with the dry film baffle 220 can be placed in a baking oven, and the temperature of the baking oven is set to 150° C. to 180° C., and the baking is performed for 1.5 hours to 2.5 hours, so as to achieve a drying process for the dry film baffle 220 to remove the water vapor in the pores 210 without damaging the dry film baffle 220. During the development process, some water vapor will remain in the pores 210, and the water vapor in the pores 210 can be volatilized by baking to prevent the water vapor in the pores 210 from affecting the subsequent filling of the resin 300.
[0075] S500 , filling the first metallization hole 110 with resin 300 .
[0076] like Figure 1 , Figure 8 and Fig. 9As shown, in some embodiments, the substrate 100 with the dry film baffle 220 attached thereto can be placed in a vacuum resin plugging machine, and the space where the substrate 100 with the dry film baffle 220 is located is first evacuated to form a negative pressure environment inside the first metallized hole 110. In this process, since the dry film baffle 220 is provided with the air hole 210, the air pressure on both sides of the dry film baffle 220 can be kept balanced during the vacuuming process, thereby preventing the dry film baffle 220 from being broken. Subsequently, the resin 300 can be poured onto the substrate 100, and under the adsorption effect of the negative pressure, the resin 300 can flow into the first metallized hole 110 and fill the first metallized hole 110 tightly to avoid the presence of filling gaps inside the first metallized hole 110. In addition, when the resin 300 passes through the air hole 210, due to the small diameter of the air hole 210 and the surface tension of the resin 300, the resin 300 can be effectively prevented from entering the second metallized hole 120 through the air hole 210.
[0077] After the filling is completed, the resin 300 may be cured. For example, the substrate 100 filled with the resin 300 may be placed in a baking oven for baking to cure the resin 300.
[0078] In other embodiments, the resin 300 may also be cured by natural drying.
[0079] S600 , grinding the resin 300 to remove the resin 300 outside the first metallization hole 110 .
[0080] In some embodiments, the resin 300 on the surface of the substrate 100, including the first surface 101 and the second surface 102 of the substrate 100, can be polished by a ceramic grinding wheel to remove excess resin 300 outside the first metallized hole 110 so that other treatments can be performed on the first surface 101 and the second surface 102 of the substrate 100 in subsequent processes.
[0081] S700 , removing the dry film blocking sheet 220 .
[0082] In some embodiments, the dry film blocking sheet 220 can be removed from the first surface 101 and the second surface 102 of the substrate 100 by chemical dissolution. For example, in some embodiments, the dry film blocking sheet 220 can be removed by dissolving the dry film blocking sheet 220 with a strong alkaline solution such as sodium hydroxide solution.
[0083] In some other embodiments, the dry film blocking sheet 220 may also be removed by grinding.
[0084] In the embodiment, after the dry film stopper 220 is removed, the substrate 100 filled with the resin 300 may be subjected to subsequent processes.
[0085] In the prior art, a dam is usually formed around the second metallized hole 120 using a dry film 200 to prevent the resin from entering the second metallized hole 120. When the hole density on the substrate 100 is high and the flow rate of the resin 300 is large, the dam is difficult to effectively block the resin 300, resulting in the resin 300 entering the second metallized hole 120.
[0086] The selective resin plugging method provided in the embodiment of the present application can realize the resin plugging operation during the circuit board processing. On the one hand, it can effectively prevent the resin from entering the second metallized hole 120 that does not need to be plugged. On the other hand, the selective resin plugging method can be applied to circuit boards with smaller hole spacing (the distance between the edges of two adjacent through holes), where the minimum hole spacing can reach 6 mil, with higher versatility and meeting higher processing requirements.
[0087] The embodiment also provides a circuit board, which can be manufactured by the selective resin plugging method provided in the embodiment.
[0088] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. 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 application. In this specification, the schematic representations of the above terms do 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. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0089] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.
Claims
1. A selective resin plugging method, characterized in that: include: Making a first metallized hole and a second metallized hole on the substrate; Laying a dry film on the surface of the substrate; Performing photolithography on the dry film to obtain a dry film blocking piece opposite to the second metallized hole, and making an air hole connected to the second metallized hole on the dry film blocking piece, so that the inner diameter D1 of the air hole is smaller than the inner diameter D2 of the second metallized hole; Filling the first metallization hole with resin; The dry film blocking sheet is removed.
2. The selective resin plugging method according to claim 1, characterized in that: The outer diameter D3 of the dry film stopper is 6 mil to 20 mil larger than the inner diameter D2 of the second metallized hole.
3. The selective resin plugging method according to claim 1 or 2, characterized in that: The inner diameter D1 of the air hole is set to 15 mil to 25 mil.
4. The selective resin plugging method according to claim 1, characterized in that: The photolithography of the dry film to obtain a dry film blocking piece opposite to the second metallized hole, and forming an air hole connected to the second metallized hole on the dry film blocking piece, so that the inner diameter D1 of the air hole is smaller than the inner diameter D2 of the second metallized hole, comprises: Exposing the dry film so that the unexposed area covers the position relative to the first metallized hole and the position of the air hole; The dry film is developed to obtain the dry film blocking sheet, and the pores are formed on the dry film blocking sheet.
5. The selective resin plugging method according to claim 1, characterized in that: Before filling the first metallization hole with resin, the selective resin plugging method further includes: The dry film baffle is dried.
6. The selective resin plugging method according to claim 5, characterized in that: The step of drying the dry film baffle comprises: The substrate with the dry film barrier sheet attached thereto is placed in a baking oven, and the temperature of the baking oven is maintained at 150° C. to 180° C., and the baking is performed for 1.5 hours to 2.5 hours.
7. The selective resin plugging method according to claim 1, 5 or 6, characterized in that: The step of filling the first metallized hole with resin comprises: Vacuuming the space where the substrate to which the dry film baffle is attached is located; The first metallization hole is filled with resin.
8. The selective resin plugging method according to claim 1, characterized in that: The method of making a first metallized hole and a second metallized hole on the substrate comprises: providing a substrate; Processing a first through hole at a first preset position of the substrate, and processing a second through hole at a second preset position; The first through hole and the second through hole are metallized.
9. The selective resin plugging method according to claim 1, characterized in that: After the first metallization hole is filled with resin, the selective resin plugging method further comprises: The resin is polished to remove the resin outside the first metallization hole.
10. A circuit board, characterized in that: The method is manufactured by the selective resin plugging method as claimed in any one of claims 1 to 9.