HDI plate and manufacturing method thereof

Abstract

The invention discloses an HDI board and a manufacturing method thereof, and the method comprises the steps: providing a core board which is provided with a first-order blind hole and is provided with an electroplating filling hole; multiple layers of daughter boards are provided, the multiple layers of daughter boards are sequentially stacked on the two sides of the core board and form a mother board through one-time pressing, and the mother board comprises a first face and a second face which are opposite to each other; a first blind hole is drilled in the first face, and a second blind hole is drilled in the second face; filling the first blind hole with a conducting material, and blocking the first blind hole; filling the second blind hole with a conduction material; and the first blind hole and the second blind hole are filled and leveled up through electroplating. Therefore, the manufacturing period can be shortened, and the interlayer reliability of finished products and the blind hole alignment precision are improved. The circuit board is widely applied to the technical field of circuit boards.

Description

Technical Field

[0001] This application relates to the field of circuit board technology, and in particular to an HDI board and its manufacturing method. Background Technology

[0002] High-Density Interconnect (HDI) printed circuit boards, or simply HDI boards, are circuit boards with high circuit density that utilize micro-blind vias / buried vias. HDI boards use micro-blind vias / buried vias to connect different layers, increasing wiring density. Therefore, the density of an HDI board increases with the number of micro-blind vias / buried vias; in other words, the higher the order of the HDI board, the higher its density. Generally, HDI boards use single-layer addition, while high-order HDI boards use double or more layers, combined with Any-layer HDI technology, to achieve even higher interconnect density. Consequently, the manufacturing cycle for high-order HDI boards is longer. Furthermore, because each blind via corresponds to one lamination during layer addition in high-order HDI boards, the alignment accuracy between layers decreases with increasing blind via order. Simultaneously, the reliability risk increases after multiple laminations, making it difficult to control the interlayer reliability and blind via misalignment in the finished high-order HDI board. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes an HDI board and its manufacturing method, which can shorten the manufacturing cycle and improve the interlayer reliability and blind via alignment accuracy of the finished product.

[0004] A method for manufacturing an HDI board according to a first aspect embodiment of this application includes:

[0005] A core board is provided, wherein the core board has first-order blind holes and is electroplated to fill the holes;

[0006] A multilayer sub-board is provided, wherein the multilayer sub-boards are sequentially stacked on both sides of the core board and formed into a mother board by a single pressing, wherein the mother board includes a first side and a second side opposite to each other;

[0007] A first blind hole is drilled on the first surface, and a second blind hole is drilled on the second surface;

[0008] The first blind hole is filled with conductive material to seal it;

[0009] The second blind hole is filled with conductive material;

[0010] Electroplating fills the first blind hole and the second blind hole.

[0011] The HDI board manufacturing method according to the embodiments of this application has at least the following beneficial effects: By stacking multiple sub-boards on both sides of a core board and then laminating them together in one step to form a mother board, the number of lamination steps is reduced, improving the reliability between finished product layers. Simultaneously, drilling holes in the multi-layer boards after lamination, compared to the method of drilling and laminating each sub-board separately in related technologies, improves the alignment accuracy of blind holes, increases production efficiency, and thus shortens the manufacturing cycle. Furthermore, by filling the blind holes on both sides with conductive material and then electroplating to fill the blind holes, the filling efficiency is improved, and the electroplating process time is shortened, further shortening the manufacturing cycle.

[0012] According to some embodiments of this application, the step of filling the second blind hole with conductive material includes:

[0013] The second blind hole is filled with conductive material;

[0014] The second side is baked to allow the conductive material to contact the pad at the bottom of the second blind hole;

[0015] And / or, the step of filling the first blind hole with conductive material and sealing the first blind hole includes:

[0016] The first blind hole is filled with conductive material;

[0017] The first side is baked to make the conductive material contact the pad at the bottom of the first blind hole.

[0018] According to some embodiments of this application, the sealing of the first blind hole includes:

[0019] The first surface is plated with metal to seal the first blind hole.

[0020] According to some embodiments of this application, the first surface is plated with metal using a flash plating process or a tin plating process.

[0021] According to some embodiments of this application, the conductive material is copper paste.

[0022] According to some embodiments of this application, after electroplating to fill the first blind hole and the second blind hole, the method for manufacturing the HDI board further includes: fabricating an outer layer pattern on the motherboard, wherein the etching spray pressure of the first surface and the second surface are respectively matched with the copper thickness, so that the line width of the first surface and the line width spacing of the second surface are consistent.

[0023] According to some embodiments of this application, before the multilayer sub-boards are sequentially stacked on both sides of the core board and formed into a mother board through a single pressing, the method for manufacturing the HDI board further includes:

[0024] Anti-etching ink is screen-printed at the first-order blind hole location;

[0025] The bonding sheet adjacent to the core board is provided with the first-order blind hole opening.

[0026] According to some embodiments of this application, the first blind hole and the second blind hole are obtained by controlled-depth drilling, wherein the drill bit is controlled to drill to the surface of the anti-etching ink during drilling.

[0027] According to some embodiments of this application, after drilling the first blind hole and the second blind hole, and before filling the first blind hole with conductive material and sealing the first blind hole, the method for manufacturing the HDI board further includes:

[0028] Remove the anti-etching ink.

[0029] The HDI board according to the second aspect of this application is manufactured using the HDI board manufacturing method described in the first aspect above.

[0030] The HDI board according to the embodiments of this application has at least the following beneficial effects: it can shorten the manufacturing cycle and improve the interlayer reliability and blind via alignment accuracy of the finished product.

[0031] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0032] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0033] Figure 1 This is a schematic diagram of an HDI board disclosed in related technologies;

[0034] Figure 2 This is a flowchart illustrating the method for manufacturing an HDI board as disclosed in an embodiment of this application;

[0035] Figure 3 This is a schematic diagram of the core board manufacturing process disclosed in the embodiments of this application;

[0036] Figure 4 This is a schematic diagram of the lamination-obtained motherboard disclosed in the embodiments of this application;

[0037] Figure 5 This is a schematic diagram of drilling a first blind hole and a second blind hole in the mother plate as disclosed in the embodiments of this application;

[0038] Figure 6 This is a schematic diagram of the motherboard after the anti-etching ink has been removed, as disclosed in the embodiments of this application;

[0039] Figure 7 This is a schematic diagram of the motherboard after the first blind hole has been filled with conductive material, as disclosed in an embodiment of this application.

[0040] Figure 8 This is a schematic diagram of the motherboard after the first side has been treated with a baking plate, as disclosed in an embodiment of this application.

[0041] Figure 9 This is a schematic diagram of the mother plate after the first side has been plated with metal, as disclosed in an embodiment of this application;

[0042] Figure 10 This is a schematic diagram of the HDI board obtained after electroplating to fill the first and second blind holes, as disclosed in the embodiments of this application.

[0043] Figure label:

[0044] 11. Core board; 111. First-order blind via; 12. Sub-board; 13. First blind via; 14. Second blind via; 15. Conductive material; 16. Thin copper; 17. Anti-etching ink; 101. First side; 102. Second side. Detailed Implementation

[0045] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0046] In the description of this application, it should be understood that the terms "center", "middle", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0047] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0048] In the description of this application, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0049] In the description of this application, the use of terms such as "as one implementation," "an embodiment," "some examples," "some embodiments," "illustrative embodiment," "example," "specific example," "some examples," etc., indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions 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 suitable manner in one or more embodiments or examples.

[0050] High-end HDI boards achieve higher interconnect density through secondary or higher layer-addition technologies combined with Any-layer HDI technology. Please refer to [link / reference]. Figure 1In related technologies, the key processes of manufacturing high-end HDI boards include: material preparation → core board 11 fabrication (laser drilling of blind holes in core board 11 → plasma plating of core board 11 → horizontal desmearing of adhesive on core board 11 → electroplating and hole filling of core board 11 → fabrication of outer layer patterns on core board 11) → first sub-board 12 (first sub-board 12 is laminated on both sides of core board 11 → laser drilling of blind holes in first sub-board 12 → plasma plating of first sub-board 12 → horizontal desmearing of adhesive on first sub-board 12 → electroplating and hole filling of first sub-board 12 → fabrication of outer layer patterns on first sub-board 12) → second sub-board 12 (second sub-board is laminated on both sides of core board 11 → second sub-board 12) Laser drilling of blind holes → Plasma plating of the second sub-board → Horizontal degumming of the second sub-board → Electroplating and hole filling of the second sub-board → Fabrication of the outer layer pattern of the second sub-board → Addition of a third sub-board (Lamination of the third sub-board on both sides of the core board 11 → Laser drilling of blind holes in the third sub-board → Plasma plating of the third sub-board → Horizontal degumming of the third sub-board → Electroplating and hole filling of the third sub-board → Fabrication of the outer layer pattern of the third sub-board) → Addition of a fourth sub-board (Lamination of the fourth sub-board on both sides of the core board 11 → Laser drilling of blind holes in the fourth sub-board → Plasma plating of the fourth sub-board → Horizontal degumming of the fourth sub-board → Electroplating and hole filling of the fourth sub-board → Fabrication of the outer layer pattern of the fourth sub-board). That is, each layer increases the number of blind vias by one order 111, but each layer increases the number of laminations. As the order of blind vias increases, the alignment accuracy between layers will decrease. At the same time, the reliability risk of the material increases after multiple laminations. This makes it difficult to control the interlayer reliability and blind via misalignment of high-order HDI boards, and also results in low production efficiency and long production cycle.

[0051] Based on this, this application provides an HDI board and its manufacturing method, which forms a mother board by laminating multiple sub-boards on both sides of a core board and then pressing them together in one step. After lamination, holes are drilled in the multi-layer board to solve the problems of long manufacturing cycle, low interlayer reliability, and low accuracy of blind hole alignment.

[0052] Meanwhile, by filling the blind holes on both sides with conductive material and then electroplating to fill the blind holes, the filling efficiency is improved and the production cycle is further shortened.

[0053] In addition, this application also provides an HDI board manufactured using the method for manufacturing an HDI board.

[0054] The contents of this application are described in detail below with reference to specific embodiments. It should be noted that the following description is merely illustrative and not a specific limitation of this application.

[0055] Reference Figure 2 and combined Figures 3 to 10 The HDI board embodiment shown in this application describes a method for manufacturing an HDI board, which includes the following steps:

[0056] S1000, a core board 11 is provided, the core board 11 is provided with a first-order blind hole 111 and the hole is filled by electroplating.

[0057] S2000, a multilayer sub-board 12 is provided. The multilayer sub-board 12 is stacked on both sides of the core board 11 and formed into a mother board by pressing once. The mother board includes a first side 101 and a second side 102 opposite to each other.

[0058] S3000, drill a first blind hole 13 on the first face 101 and a second blind hole 14 on the second face 102.

[0059] S4000, fill the first blind hole 13 with conductive material 15 to seal the first blind hole 13.

[0060] S5000, fill the second blind hole 14 with conductive material 15.

[0061] S6000, electroplating fills the first blind hole 13 and the second blind hole 14.

[0062] The HDI board manufacturing method of this application embodiment involves stacking multiple sub-boards 12 on both sides of a core board 11 and then laminating them together in one step to form a mother board. This reduces the number of lamination steps and improves the reliability between the finished product layers. Simultaneously, drilling is performed on the multi-layer board after lamination. Compared to the method of drilling and laminating each sub-board 12 separately in related technologies, this improves the alignment accuracy of blind holes, increases production efficiency, and shortens the manufacturing cycle. Furthermore, by filling the blind holes on both sides with conductive material 15 and then electroplating to fill the blind holes, the material and electroplating time required for filling the holes can be reduced, which helps to improve the filling efficiency and shorten the operation time of the electroplating process, thereby further shortening the manufacturing cycle.

[0063] Furthermore, by sealing the first blind hole 13, it can be ensured that the conductive material 15 in the first blind hole 13 will not fall off or shift when the second blind hole 14 is filled with conductive material 15. This helps to ensure the reliability of the conductive material 15 filling the first blind hole 13, improves the finished product quality of the motherboard, and reduces the situation where the conductive material 15 in the first blind hole 13 falls out, resulting in quality abnormalities and rework, affecting the delivery date and production cycle, thereby achieving the effect of ensuring the production cycle.

[0064] Please combine Figure 3 In some embodiments, considering that the drilling depth cannot be guaranteed when drilling the first blind hole 13 and the second blind hole 14 on the motherboard, there is a risk that the drill bit travels too far and damages the inner layer pads. Therefore, before step S2000, the HDI board manufacturing method further includes steps S1100-S1200:

[0065] S1100, screen print anti-etch ink 17 at the first-order blind hole 111 position.

[0066] This allows the inner layer pads of the core board 11 to be protected when drilling the first blind hole 13 and the second blind hole 14, thus avoiding damage to the inner layer pads.

[0067] Optionally, the thickness of the etch-resistant ink 17 is greater than 50 μm, and the size of the etch-resistant ink 17 matches the size of the first-order blind via 111 of the core board 11, so that the etch-resistant ink 17 completely covers the inner layer pads. This allows for a certain drilling depth error for the drill bit and effectively protects the inner layer pads.

[0068] S1200, the bonding sheet (i.e., semi-cured sheet, also known as PP sheet) of the sub-board adjacent to the core board 11 is set with a window corresponding to the first-order blind hole 111.

[0069] This allows the anti-etching ink 17 to be avoided, so that the opening of the adhesive sheet can be completely covered by the anti-etching ink 17.

[0070] Optionally, the window radius r2 of the adhesive sheet is greater than the radius r1 of the first-order blind hole 111, and r2-r1≥0.30mm, for example, r2-r1=0.35mm, 0.40mm or 0.50mm, etc.

[0071] Please combine Figure 4 and Figure 5 In some embodiments, the first blind hole 13 and the second blind hole 14 are obtained by controlled-depth drilling, where the drill bit is controlled to drill to the surface of the etch-resistant ink 17. This ensures that the inner layer pads of the core board 11 are not damaged when drilling the first blind hole 13 and the second blind hole 14.

[0072] Please combine Figure 6 In some embodiments, after step S3000: drilling the first blind hole 13 and the second blind hole 14, and before step S4000: filling the first blind hole 13 with conductive material 15 and sealing the first blind hole 13, the method for manufacturing the HDI board further includes:

[0073] S3500, Remove Anti-etching Ink 17.

[0074] This exposes the inner layer pads, ensuring that the conductive material 15 can contact and conduct with the inner layer pads after the first blind via 13 and the second blind via 14 are filled with conductive material 15, so as to facilitate interconnection of the circuits in each layer.

[0075] Please combine Figures 7 to 9 In some embodiments, step S4000 specifically includes the following steps S4100-S4300:

[0076] S4100, fill the first blind hole 13 with conductive material 15.

[0077] Optionally, the conductive material 15 is copper paste. This can both fill blind holes to ensure the structural reliability of the motherboard and ensure the continuity of connections between layers.

[0078] It should be noted that in this embodiment, copper paste, also known as conductive paste, is mainly composed of copper, tin, and tripropylene glycol ether. It is mainly used in electronic manufacturing processes, specifically for making circuits connect to each other.

[0079] Optionally, copper paste is inserted into the first blind hole 13 or the second blind hole 14 through a plugging aluminum mesh plate to ensure the accuracy of blind hole filling.

[0080] Understandably, in other embodiments, the conductive material 15 may also be copper paste or aluminum sheet, etc.

[0081] S4200, the first surface 101 is baked to make the conductive material 15 contact the pad at the bottom of the first blind hole 13.

[0082] Considering that the first blind via 13 and the second blind via 14 are formed by drilling after the multilayer sub-board 12 is laminated, the first blind via 13 and the second blind via 14 are relatively deep, and the blind vias drilled by the drill bit are usually V-shaped. After the copper paste is filled, there will be some air at the bottom of the deep V blind vias (i.e., the first blind via 13 and the second blind via 14), which prevents the copper paste from completely entering the bottom of the first blind via 13 and the second blind via 14 and contacting the inner layer pads of the core board 11, thus affecting the circuit conductivity between the layers. Based on this, the high temperature of the baking process is used to melt the copper paste so that the copper paste flows onto the inner layer pads and makes complete contact with them, thereby ensuring the interconnection between the layers and improving the reliability of the motherboard.

[0083] Optionally, the baking temperature can be 200±10℃ to ensure that the copper paste melts at high temperature and flows completely onto the inner layer pads during the baking process, so that the copper paste is in complete contact with the inner layer pads.

[0084] It should be noted that during the board baking process, in order to prevent the copper paste from flowing out, the side with the copper paste filling should be facing upwards during the baking process. That is, when baking the first side 101, the first side 101 should be facing upwards so that the copper paste in the first blind hole 13 melts and flows to the pad at the bottom of the first blind hole 13 without flowing out of the first blind hole 13.

[0085] S4300, plate the first surface 101 with metal to seal the first blind hole 13.

[0086] Considering that the copper paste, after baking and cooling, is in complete contact with the pads at the bottom of the blind via, when baking the second side 102, the first blind via 13 faces downwards. At this time, the copper paste inside the first blind via 13 will melt due to high temperature and flow out. Therefore, before filling the second blind via 14 with the conductive material 15, the first side 101 is plated with metal to seal the first blind via 13. This ensures that the copper paste filling the first blind via 13 is sealed within it, preventing it from flowing out during the baking process of the second side 102. This ensures the reliability of the conductive material 15 filling the first blind via 13, improves the finished product quality of the motherboard, and reduces the likelihood of quality defects and rework due to copper paste flowing out of the first blind via 13, affecting delivery time and production cycle, thus ensuring the production cycle.

[0087] Please refer to Figure 9 In some embodiments, a flash plating process is used to plate the first surface 101 with metal to quickly deposit a thin layer of copper 16 of 2µm-3µm onto the copper paste surface of the first blind hole 13. Since the melting point of the thin copper 16 is higher than that of the copper paste and the baking temperature, the baking temperature cannot destroy the copper plating layer. This allows the copper paste in the first blind hole 13 to be sealed in a short time, and also provides a basis for subsequent electroplating to fill the hole, which helps to reduce processing time and avoid taking up a long manufacturing cycle.

[0088] In other embodiments, a tin-plating process is used to plate the first surface 101 with metal to deposit a thin layer of tin on the copper paste surface of the first blind via 13. Since the melting point of tin is higher than the baking temperature, the baking temperature cannot destroy the tin plating layer, thereby ensuring the sealing effect of the tin plating layer on the solder paste in the first blind via 13 when baking the second surface 102, ensuring the filling effect of the copper paste on the first blind via 13 and the connection and conductivity between the copper paste and each layer of sub-board 12.

[0089] It should be noted that when the first side 101 is plated with metal using the tin plating process, the tin plating layer needs to be removed after the second side 102 is baked to ensure the speed of electroplating and the conductivity reliability of the motherboard.

[0090] In some embodiments, step S5000 specifically includes the following steps S5100-S5200:

[0091] S5100, fill the second blind hole 14 with conductive material 15.

[0092] S5200, the second side 102 is baked to make the conductive material 15 contact the pad at the bottom of the second blind hole 14.

[0093] The operation process and requirements of steps S4100 and S5100 are the same, and the operation process and requirements of steps S4200 and S5200 are the same, with the same technical effect, so they will not be described again here.

[0094] Please combine Figure 9 and Figure 10 In some embodiments, after the first surface 101 and the second surface 102 are baked, the copper paste in the first blind hole 13 and the second blind hole 14 sinks to fully contact the inner layer pads, and the copper paste appears recessed in the first blind hole 13 and the second blind hole 14, and cannot completely fill the first blind hole 13 and the second blind hole 14. Based on this, the HDI board manufacturing method further includes step S6000:

[0095] S6000, electroplating fills the first blind hole 13 and the second blind hole 14.

[0096] This allows the first blind hole 13 and the second blind hole 14 to be filled, preventing the surface of the motherboard from being recessed at the blind hole location, thus improving the reliability of the circuit connection and the flatness of the board surface.

[0097] It should be noted that electroplating fills the first blind hole 13 and the second blind hole 14, which means completely or approximately fills them. The finished product recess standard of HDI board is less than 18um. That is, after electroplating fills, the height difference between the copper surface in the first blind hole 13 (or the second blind hole 14) and the first surface 101 (or the second surface 102) is less than 18um, which can be called double-sided blind hole recess filled by electroplating, so as to facilitate the subsequent outer layer pattern making and solder mask processing.

[0098] In some embodiments, in order to facilitate flash plating to seal the first blind hole 13 and electroplating to fill the first blind hole 13 and the second blind hole 14, a copper plating process is required before performing steps S4300 and S6000 to construct a conductive copper layer on the first surface 101 and the second surface 102 to provide necessary support for flash plating and electroplating.

[0099] In some embodiments, after electroplating to fill the first blind via 13 and the second blind via 14, the method for manufacturing the HDI board further includes step S7000:

[0100] S7000: Create outer layer patterns on the motherboard. The etching spray pressure of the first surface 101 and the second surface 102 are matched with the copper thickness to ensure that the line width of the first surface 101 and the line width spacing of the second surface 102 are consistent.

[0101] This ensures that the line width spacing of the first surface 101 and the second surface 102 is consistent, which helps to meet impedance requirements and improve the stability of electrical performance and signal integrity.

[0102] Optionally, considering that when the first blind hole 13 is sealed using a flash plating process, a layer of copper is also plated on the first surface 101 of the motherboard, resulting in different copper thicknesses on the first surface 101 and the second surface 102 after electroplating to fill the first blind hole 13 and the second blind hole 14 in step S6000, the etching spray pressure on different surfaces of the motherboard is adjusted according to the actual copper thickness so that the etching spray pressure on the first surface 101 is different from that on the second surface 102, thereby ensuring the consistency of the line width spacing between the first surface 101 and the second surface 102.

[0103] In some embodiments, the step S3500 above, which involves removing the resist ink 17, can be achieved by using the outer layer pattern DES stripping section (sodium hydroxide stripping solution) in step S7000 to remove the resist ink 17 from the first blind hole 13 and the second blind hole 14, thereby making reasonable use of materials and improving the reusability of the manufacturing process. Alternatively, the resist ink 17 can also be removed by dripping sodium hydroxide stripping solution or other chemical agents into the first blind hole 13 and the second blind hole 14.

[0104] Optionally, since the resist ink 17 is located at the bottom of the deep V blind vias (first blind via 13 and second blind via 14), it takes a certain amount of time for the stripping solution to enter the first blind via 13 and second blind via 14 and come into contact with the resist ink 17. Based on this, when removing the resist ink 17 through the outer layer pattern DES stripping section in step S7000, the stripping speed needs to be reduced to 1m / mil (equivalent to the parameters of stripping two 50um thick photosensitive dry films) to avoid the problem of incomplete stripping of the resist ink 17 at the bottom of the blind vias, and to ensure that the inner layer pads are exposed.

[0105] As can be seen, the key processes of the HDI board manufacturing method provided in this application include: material cutting → laser drilling of blind holes on the core board 11 → electroplating and filling of the first-order blind holes 111 → fabrication of the outer layer pattern on the core board 11 → silkscreen printing of anti-etching ink 17 → multilayer sub-boards 12 are stacked on both sides of the core board 11 and pressed together in one go → controlled-depth drilling → removal of anti-etching ink 17 → copper paste filling of the first blind hole 13 → baking of the first side 101 → horizontal copper plating of the first side 101 → flash plating of the first side 101 → copper paste filling of the second blind hole 14 → baking of the second side 102 → horizontal copper plating of the second side 102 → electroplating and filling of the first blind hole 13 and the second blind hole 14 → fabrication of the outer layer pattern on the first side 101 and the second side 102.

[0106] Compared to the lamination process in related technologies where each layer is added corresponds to one lamination, this method effectively reduces the number of laminations, improves the reliability between finished layers and the alignment accuracy of blind holes, and increases production efficiency, thereby shortening the production cycle. Furthermore, by filling the blind holes on both sides with conductive material 15 and then electroplating to fill them, the material and electroplating time required for filling are reduced, which helps improve filling efficiency and shortens the electroplating process time, further shortening the production cycle. In addition, by sealing the first blind hole 13, it is ensured that the copper paste in the first blind hole 13 will not flow out during the baking of the second side 102, thus ensuring the reliability of the copper paste filling of the first blind hole 13, improving the finished product quality of the motherboard, and reducing the possibility of quality defects and rework due to copper paste flowing out of the first blind hole 13, affecting delivery time and production cycle, thereby achieving the effect of ensuring the production cycle.

[0107] Please combine Figure 2 and Figure 10 This application also provides an HDI board, which is manufactured using the HDI board manufacturing method described above.

[0108] It is understandable that since HDI boards are manufactured using the aforementioned HDI board manufacturing method, they possess the beneficial effects of the aforementioned HDI board manufacturing method, which will not be elaborated upon here.

[0109] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. A method for manufacturing an HDI board, characterized in that, include: A core board is provided, wherein the core board has first-order blind holes and is electroplated to fill the holes; A multilayer sub-board is provided, wherein the multilayer sub-boards are sequentially stacked on both sides of the core board and formed into a mother board by a single pressing, wherein the mother board includes a first side and a second side opposite to each other; A first blind hole is drilled on the first surface, and a second blind hole is drilled on the second surface; The first blind hole is filled with conductive material to seal it; The second blind hole is filled with conductive material; Electroplating fills the first blind hole and the second blind hole.

2. The method for manufacturing an HDI board according to claim 1, characterized in that, The step of filling the second blind hole with conductive material includes: The second blind hole is filled with conductive material; The second side is baked to allow the conductive material to contact the pad at the bottom of the second blind hole; And / or, the step of filling the first blind hole with conductive material and sealing the first blind hole includes: The first blind hole is filled with conductive material; The first surface is baked to allow the conductive material to contact the pad at the bottom of the first blind hole.

3. The method for manufacturing an HDI board according to claim 2, characterized in that, The sealing of the first blind hole includes: The first surface is plated with metal to seal the first blind hole.

4. The method for manufacturing an HDI board according to claim 3, characterized in that, The first surface is plated with metal using a flash plating process or a tin plating process.

5. The method for manufacturing an HDI board according to claim 1, characterized in that, The conductive material is copper paste.

6. The method for manufacturing an HDI board according to any one of claims 1-5, characterized in that, After electroplating to fill the first blind hole and the second blind hole, the method for manufacturing the HDI board further includes: fabricating an outer layer pattern on the motherboard, wherein the etching spray pressure of the first side and the second side are respectively matched with the copper thickness, so that the line width of the first side and the line width spacing of the second side are consistent.

7. The method for manufacturing an HDI board according to claim 1, characterized in that, Before the multilayer sub-boards are sequentially stacked on both sides of the core board and formed into a mother board through a single pressing, the method for manufacturing the HDI board further includes: Anti-etching ink is screen-printed at the first-order blind hole location; The bonding sheet adjacent to the core board is provided with the first-order blind hole opening.

8. The method for manufacturing an HDI board according to claim 7, characterized in that, The first blind hole and the second blind hole are obtained by controlled-depth drilling, during which the drill bit is controlled to drill to the surface of the anti-etching ink.

9. The method for manufacturing an HDI board according to claim 7, characterized in that, After drilling the first blind hole and the second blind hole, and before filling the first blind hole with conductive material and sealing the first blind hole, the method for manufacturing the HDI board further includes: Remove the anti-etching ink.

10. An HDI board, characterized in that, It is manufactured using the method for manufacturing an HDI board as described in any one of claims 1-9.

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