Substrate with non-metallization step blind groove and processing method thereof

Abstract

The invention discloses a substrate with a non-metallization step blind slot and a processing method thereof, and the processing method comprises the steps: providing a laminated plate, manufacturing an inner-layer circuit, an inner-layer target and a first window on an outer-layer copper foil of the laminated plate, and then arranging an insulation adding layer and a copper foil adding layer on the outer-layer copper foil in a laminated manner; a second window is manufactured on the copper foil added layer in the mode of grabbing the inner layer target for alignment; laser groove burning is carried out based on the second window and the first window in sequence, a first-order blind groove with the second window as a groove opening and the local part of the outer-layer copper foil as the groove bottom and a second-order blind groove with the first window as the groove opening and the local part of the inner-layer copper foil of the laminated plate as the groove bottom are manufactured, and the first-order blind groove and the second-order blind groove form a stepped blind groove together; and preparing an outer circuit on the copper foil added layer, and removing the bottoms of the first-order blind groove and the second-order blind groove to prepare a non-metallization step blind groove, thereby obtaining the substrate. The processing method is simple and reasonable, the processing cost is low, the obtained substrate is high in size precision and good in appearance quality, and the production requirements in the field of circuit boards are met.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit boards, and in particular to a substrate with a non-metallized step blind groove and a processing method thereof. Background Art

[0002] With the continuous increase in semiconductor packaging integration density, special-shaped structure packaging has undoubtedly greatly increased space utilization, and has gradually entered various sub-segments, becoming one of the key research process routes. For non-metallized step blind groove structures, there are currently two mainstream processing technologies:

[0003] The first processing technology: prepare multiple core boards (also called core boards), and preset through grooves on the core boards of relevant layers; then rivet the multiple core boards together to form a stepped blind groove structure.

[0004] The first processing technology mentioned above is simple and easy to implement, but because it is made by riveting multiple core plates together, it will cause poor alignment accuracy between layers and low product yield.

[0005] The second processing technology: first use the lamination process to make a multi-layer composite substrate; then use window opening and laser technology to make a first-order blind groove; then remove the bottom copper of the first-order blind groove through pre-treatment, film pasting, exposure, development and etching processes in sequence to expose the insulating layer; then use UV laser technology to burn the second-order blind groove, and then remove the bottom copper of the second-order blind groove through pre-treatment, film pasting, exposure, development and etching processes in sequence to form a non-metallized step blind groove design.

[0006] The second processing technology mentioned above is not only complicated in processing flow and high in processing cost, but also in processing precision. For example, the window opening precision of the second-order blind groove is generally only ±25~±50μm, and the alignment precision between the step grooves is generally only 15~25μm. In addition, UV laser will damage the groove edge, thus affecting the product appearance.

[0007] In view of this, the present invention is proposed. Summary of the invention

[0008] In order to overcome the above-mentioned defects, the present invention provides a substrate with a non-metallized stepped blind groove and a processing method thereof. The processing method is simple and reasonable, has low processing cost and high processing efficiency, and the obtained substrate has high dimensional accuracy and good appearance quality, which well meets the production needs in the field of circuit boards.

[0009] The technical solution adopted by the present invention to solve the technical problem is: a method for processing a substrate with a non-metallized step blind groove, comprising:

[0010] Providing a laminated board, the laminated board having an outer copper foil located at the outermost side and an inner copper foil located inside the outer copper foil;

[0011] While producing the inner layer circuit and the inner layer target on the outer layer copper foil by using a pattern production process, a first window is also produced on a preset area of ​​the outer layer copper foil;

[0012] Adding layers to the laminated board after pattern production, so as to sequentially stack an insulating build-up layer and a copper foil build-up layer on the outer copper foil;

[0013] Opening a window in a preset area of ​​the copper foil build-up layer by grabbing the inner layer target for alignment to obtain a second window, wherein the second window is aligned with the first window in the thickness direction of the laminate, and the alignment degree is controlled to be less than 10 μm, and the area of ​​the second window is larger than that of the first window;

[0014] Laser grooves are sequentially burned based on the second window and the first window to obtain a first-order blind groove with the second window as the groove opening and the part of the outer copper foil as the groove bottom, and a second-order blind groove with the first window as the groove opening and the part of the inner copper foil as the groove bottom; the second-order blind groove is connected with the first-order blind groove and together forms a stepped blind groove;

[0015] While the outer layer circuit is made on the copper foil build-up layer by using a pattern making process, the bottoms of the first-order blind groove and the second-order blind groove are removed to make a non-metallized step blind groove, and then a substrate with the non-metallized step blind groove is made.

[0016] As a further improvement of the present invention, a board obtained by sequentially performing pattern making and layer adding on the laminated board is defined as a first intermediate board;

[0017] The manufacturing method of the second window is: firstly laser processing the first intermediate board to expose the inner layer target; then using the graphic production process to open a window in the preset area of ​​the copper foil build-up layer, and during the window opening process, the inner layer target is grasped for positioning, so that the alignment degree between the obtained second window and the first window is controlled below 10μm.

[0018] As a further improvement of the present invention, the pattern production process includes sequentially performing pre-film coating treatment, coating with an anti-corrosion photosensitive film, exposure, development, etching and film stripping processing.

[0019] As a further improvement of the present invention, the pattern production process includes sequentially performing film pre-treatment, coating of resist photosensitive film, exposure, development, pattern electroplating, film stripping, baking and flash etching.

[0020] As a further improvement of the present invention, the horizontal distance between the inner wall of the second window and the inner wall of the first window is not less than 75 μm.

[0021] As a further improvement of the present invention, the processing parameters of the laser groove burning are: mask thickness is 1.8-2.1 mm, laser pulse width is 5-8 μs, laser energy is 3.2-8.5 MJ, number of laser shots is 2-8 shots, laser groove wall slope is ≤15 μm, and groove wall roughness is ≤15 μm.

[0022] As a further improvement of the present invention, a horizontal distance between an inner side wall of the first-order blind groove and an inner side wall of the second-order blind groove is not less than 75 μm.

[0023] As a further improvement of the present invention, the insulating layer is made of prepreg or pure glue material.

[0024] The present invention further provides a substrate with a non-metallized step blind groove, which is manufactured by using the processing method of the substrate with a non-metallized step blind groove described in the present invention.

[0025] The beneficial effects of the present invention are as follows: compared with the step blind groove processing technology in the prior art, the processing method provided by the present invention is simple, reasonable, low in processing cost and high in processing efficiency. In particular, the present invention significantly improves the dimensional accuracy (alignment degree can reach below 10μm), appearance quality (no damage to the inner wall of the blind groove) and other properties of the non-metallized step blind groove structure by optimizing and innovating the manufacturing methods of the first and second windows and laser burning grooves, thereby meeting the production needs in the circuit board field very well. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a flow chart of a method for processing a substrate having a non-metallized step blind groove according to Embodiment 1 of the present invention;

[0027] Figure 2 is a schematic cross-sectional structure diagram of the laminated board described in Example 1 of the present invention;

[0028] Figure 3 It is a schematic diagram of the cross-sectional structure of the laminated board after pattern production in Example 1 of the present invention;

[0029] Figure 4 is a schematic cross-sectional structure diagram of the first intermediate plate obtained in Example 1 of the present invention;

[0030] Figure 5 It is a schematic cross-sectional structure diagram of the first intermediate plate after a second window is obtained by opening a window in Embodiment 1 of the present invention;

[0031] Figure 6 It is a schematic cross-sectional structure diagram of the first intermediate plate after the first laser groove burning is performed to obtain a first-order blind groove in Embodiment 1 of the present invention;

[0032] Figure 7It is a schematic cross-sectional structure diagram of the first intermediate plate after laser groove burning for the second time to obtain a second-order blind groove in Embodiment 1 of the present invention;

[0033] Figure 8 Schematic diagram of the cross-sectional structure of the substrate obtained in Example 1 of the present invention.

[0034] Combined with the accompanying drawings, the following description is given:

[0035] 1. Build-up board; 10. Outer copper foil; 11. Inner copper foil; 12. Insulating substrate; 20. Inner circuit; 21. First window; 30. Insulating build-up layer; 31. Copper foil build-up layer; 4. Second window; 5. First-order blind groove; 6. Second-order blind groove; 7. Step blind groove; 8. Outer circuit; 9. Non-metallized step blind groove. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0037] Embodiment 1:

[0038] Please see attached Figures 1 to 8 As shown, this embodiment 1 provides a method for processing a substrate having a non-metallized step blind groove, which mainly includes the following processing steps:

[0039] S1: providing a laminated board 1 , wherein the laminated board 1 is provided with an outer copper foil 10 located at the outermost side and an inner copper foil 11 located inside the outer copper foil 10 .

[0040] Specifically, the laminate 1 is formed by alternately stacking and pressing multiple copper foil layers and multiple insulating substrates 12. For ease of understanding and description, the outermost copper foil layer is defined as the outer copper foil 10, and the other copper foil layers located inside the outer copper foil 10 are defined as the inner copper foil 11. Figure 2 The figure shows the situation that the outer copper foil 10 and the inner copper foil 11 are both configured as one layer, but it can be understood that in actual application of the present application, the number of layers of the outer copper foil 10 and the inner copper foil 11 is not limited to the above one layer, such as: the outer copper foil 10 can be configured as two layers, and the inner copper foil 11 can be configured as two or more layers, which can be determined according to product design requirements.

[0041] In addition, in this embodiment, the insulating substrate 12 may be made of, but not limited to, a prepreg or pure glue. There are no restrictions on the thickness of the insulating substrate 12 and the copper foil layer, which are determined according to product design requirements.

[0042] S2: while manufacturing the inner layer circuit 20 and the inner layer target on the outer layer copper foil 10 by using a pattern manufacturing process, a first window 21 is also manufactured on a preset area of ​​the outer layer copper foil 10 .

[0043] Specifically, the processing method preferably adopted in the above S2 is: after the laminate 1 is subjected to pre-coating treatment, anti-corrosion photosensitive film coating, exposure, development, etching and film stripping, the inner layer circuit 20, the inner layer target and the first window 21 are manufactured on the outer copper foil 10; see the attached Figure 3 shown.

[0044] The above-mentioned "pre-coating treatment, coating with anti-corrosion photosensitive film, exposure, development, etching and film stripping" processes are all common technical means in the field of circuit board processing, so they will not be described in detail here, but only briefly explained as follows:

[0045] ① Pre-coating treatment: the laminate 1 is subjected to micro-etching or roughening treatment (the degree of roughening can be designed to be medium roughening or super roughening according to requirements), cleaning and drying treatment in sequence to enhance the bonding force between the anti-corrosion photosensitive dry film and the outer copper foil 10 in the subsequent process.

[0046] ② Laminating with anti-corrosion photosensitive film: Laminating the anti-corrosion photosensitive dry film on the outer copper foil 10. Furthermore, the laminating operation can be carried out by a vacuum laminating machine, which has high flatness and can further enhance the bonding strength between the anti-corrosion photosensitive dry film and the outer copper foil 10.

[0047] ③Exposure and development: Exposure is to expose part of the resist photosensitive dry film according to the work data; development is to remove the unexposed area of ​​the resist photosensitive dry film. Furthermore, the exposure operation can be carried out by LDI exposure machine, which has high exposure accuracy and accurate alignment.

[0048] ④ Etching and film stripping: Etching is to remove the portion of the outer copper foil 10 exposed outside the anti-etching photosensitive dry film, so as to form the inner layer circuit 20, the inner layer target and the first window 21 on the outer copper foil 10 (it can be understood that the inner layer circuit 20 and the inner layer target are covered by the anti-etching photosensitive dry film at that time); film stripping is to remove the anti-etching photosensitive dry film with a strong alkaline solution, so that the inner layer circuit 20 and the inner layer target can be exposed.

[0049] In addition, after completing the above S2, an AOI inspection is performed on the inner layer circuit 20, the inner layer target and the first window 21 through an optical scanning method.

[0050] S3: adding layers to the built-up board 1 after patterning, so as to sequentially stack an insulating build-up layer 30 and a copper foil build-up layer 31 on the outer copper foil 10 .

[0051] Specifically, after completing the above S2 operation, the insulating build-up layer 30 and the copper foil build-up layer 31 are sequentially stacked on the outer copper foil 10, and then a lamination operation is performed to obtain a first intermediate board; Figure 4 shown.

[0052] Furthermore, the insulating layer 30 may be made of, but not limited to, a prepreg or pure adhesive material; the lamination process may preferably be performed by a hot pressing lamination process.

[0053] In addition, before the insulating build-up layer 30 and the copper foil build-up layer 31 are sequentially stacked on the outer copper foil 10, the intermediate board obtained in S2 can be subjected to pre-treatments such as roughening / browning, cleaning and drying in sequence according to product processing requirements to enhance the bonding strength between the insulating build-up layer 30 and the outer copper foil 10.

[0054] S4: A window is opened in a preset area of ​​the copper foil build-up layer 31 by grabbing the inner layer target for alignment to obtain a second window 4, wherein the second window 4 is aligned with the first window 21 in the thickness direction of the laminate 1, and the alignment degree is controlled to be less than 10 μm, and the area of ​​the second window 4 is larger than that of the first window 21.

[0055] Specifically, the processing method preferably adopted in the above S4 is: firstly, laser processing is performed on the first intermediate plate to expose the inner layer target; then, the first intermediate plate is subjected to pre-coating treatment, anti-corrosion photosensitive film coating, exposure, development, etching and film stripping in sequence, and then a window is opened on the preset area of ​​the copper foil build-up layer 31 to obtain the second window 4, which can be referred to in the attached Figure 5 As shown. It can be understood that ① the graphic production process used in this embodiment when making the second window 4 is the same as the graphic production process used in the above S2, so it will not be repeated here. ② In each process of "pre-film coating, anti-corrosion photosensitive film coating, exposure, development, etching and film stripping processing" in the above S4, the inner layer target is grasped for alignment, thereby significantly improving the inter-layer alignment, and achieving the alignment between the second window 4 and the first window 21 controlled to be less than 10μm, thereby providing a guarantee for obtaining high-precision step blind grooves in the post-process.

[0056] Furthermore, in order to ensure the quality of the non-metallized step blind groove 9 obtained in the subsequent process, the present embodiment also optimizes the size of the second window 4 and the first window 21, specifically: Figure 5 As shown, the opening area of ​​the second window 4 is larger than the opening area of ​​the first window 21, and the horizontal spacing L1 between the inner wall of the second window 4 and the inner wall of the first window 21 is optimally controlled to be no less than 75 μm (the specific reasons for this design are shown in the corresponding content in S5 below).

[0057] S5: Laser burning grooves is performed based on the second window 4 and the first window 21 in sequence to obtain a first-order blind groove 5 with the second window 4 as the groove opening and the outer copper foil 10 as the groove bottom, and a second-order blind groove 6 with the first window 21 as the groove opening and the inner copper foil 11 as the groove bottom; the second-order blind groove 6 is connected with the first-order blind groove 5 and together constitutes a stepped blind groove 7.

[0058] Specifically, the processing method preferably adopted in the above S5 is: firstly, laser burning grooves are performed for the first time based on the second window 4 to obtain a first-order blind groove 5 with the second window 4 as the groove opening and the outer copper foil 10 as the groove bottom, and the first window 21 is also exposed, that is, the first window 21 and the groove bottom of the first-order blind groove 5 are completely not filled and / or covered by the insulating layer 30, which can be referred to in the attached Figure 6 As shown; then, a second laser groove is burned based on the first window 21 to obtain a second-order blind groove 6 with the first window 21 as the groove opening and the inner copper foil 11 as the groove bottom. It can be understood that the groove bottom of the second-order blind groove 6 is not covered by the insulating substrate 12, and the second-order blind groove 6 is connected with the first-order blind groove 5 and together forms a stepped blind groove 7, which can be seen in the attached Figure 7 shown.

[0059] Based on the manufacturing method of the first window 21 and the second window 4 adopted in this embodiment, it can be known that the laser burning groove processing method used in this embodiment is essentially a copper window method (conformal mask). By means of this copper window method, it can be ensured that the deviation value between the second-order blind groove 6 and the first-order blind groove 5 is controlled below 10μm, thereby significantly improving the overall dimensional accuracy of the step blind groove 7.

[0060] Furthermore, in the present embodiment, the processing parameters preferably adopted for the above two laser groove burning processes are: mask thickness is 1.8-2.1 mm, laser pulse width is 5-8 μs, laser energy is 3.2-8.5 MJ, number of laser shots is 2-8 shots, laser groove wall slope is ≤15 μm, and groove wall roughness is ≤15 μm.

[0061] Further, based on the optimization of the sizes of the second window 4 and the first window 21 in S4, the horizontal spacing L2 between the inner side wall of the first-order blind groove 5 and the inner side wall of the second-order blind groove 6 obtained in this embodiment is also optimized to be not less than 75 μm, as shown in the attached Figure 7 As shown; in this way, when the second laser groove is burned, the copper foil at the bottom of the first-step blind groove 5 is used as a barrier to effectively prevent the insulating substrate underneath from being damaged, thereby well ensuring the quality of the non-metallized step blind groove 9 obtained in the post-process.

[0062] S6: While the outer layer circuit 8 is produced on the copper foil build-up layer 31 by using a graphic production process, the bottoms of the first-order blind groove 5 and the second-order blind groove 6 are removed to produce a non-metallized step blind groove 9, and then a substrate having the non-metallized step blind groove 9 is produced.

[0063] Specifically, the preferred processing method of S6 is: the intermediate plate obtained in S5 is defined as the second intermediate plate (its cross-sectional structure can be found in the attached Figure 7 As shown in the figure, the second intermediate board is subjected to pre-coating treatment, anti-corrosion photosensitive film coating, exposure, development, etching and film stripping in sequence, so as to realize the production of outer layer circuit 8 on the copper foil build-up layer 31, and at the same time, the bottom of the first-order blind groove 5 and the second-order blind groove 6 are etched away to obtain the non-metallized step blind groove 9, and then the substrate described in the present application is obtained, which can be referred to in the attached figure. Figure 8 shown.

[0064] It is understandable that the pattern production process used in the above S6 is the same as the pattern production process used in the above S2, so it will not be described here in detail.

[0065] In addition, according to product design requirements, the substrate can also be subjected to conventional interlayer conduction operations (i.e., the outer layer circuit 8 and the inner layer circuit 20 are connected through drilling, copper plating, electroplating and other related processes), surface treatment, molding, electrical testing, finished product inspection, packaging and shipment, etc., so as to complete the subsequent production of the substrate finished product with non-metallized step blind groove.

[0066] From the above content, it can be seen that compared with the step blind groove processing technology in the prior art, the processing method provided by the present application is simple, reasonable, low in processing cost and high in processing efficiency. In particular, the present application optimizes and innovates the production methods of the first and second windows, as well as laser burning grooves, etc., thereby significantly improving the dimensional accuracy (alignment can reach less than 10μm), appearance quality (no damage to the inner wall of the blind groove) and other performance of the non-metallized step blind groove structure, and well meets the production needs in the circuit board field.

[0067] Embodiment 2:

[0068] This embodiment 2 also provides a processing method for a substrate having a non-metallized stepped blind groove, and compared with embodiment 1, the substrate processing method provided by this embodiment 2 has the following differences: the graphic production process used in this embodiment 2 when producing the inner layer circuit 20, the first window 21, the second window 4 and the outer layer circuit 8, and removing the bottom of the first-order blind groove 5 and the second-order blind groove 6 is different from that of embodiment 1.

[0069] Specifically, the pattern production process used in the second embodiment includes pre-treatment of coating, coating of resist photosensitive film, exposure, development, pattern electroplating, film stripping, baking and flash etching. The following is only an example of producing the inner layer circuit 20 and the first window 21 for explanation:

[0070] ① Pre-coating treatment: the laminate 1 is subjected to micro-etching or roughening treatment (the degree of roughening can be designed to be medium roughening or super roughening according to requirements), cleaning and drying treatment in sequence to enhance the bonding force between the anti-plating photosensitive dry film and the outer copper foil 10 in the subsequent process.

[0071] ② Coating with anti-plating photosensitive film: coating the anti-plating photosensitive dry film on the outer copper foil 10.

[0072] ③Exposure and development: Exposure is to expose part of the area of ​​the resist-plating photosensitive dry film according to the operating data; development is to remove the unexposed area of ​​the resist-plating photosensitive dry film.

[0073] ④ Graphic electroplating: a copper plating layer is plated on the exposed area of ​​the outer copper foil 10 (i.e., the area exposed outside the anti-plating photosensitive dry film), thereby forming the prototype of the inner layer circuit 20 and the prototype of the inner layer target;

[0074] ⑤ Stripping and baking: Stripping is to use a strong alkaline solution to remove the anti-plating photosensitive dry film; baking is to dry the board to facilitate post-processing.

[0075] ⑥ Flash etching: flash etching is performed on the entire copper surface of the board to etch away the area on the outer copper foil 10 that is not covered by the copper plating layer, so as to obtain the inner layer circuit 20, the inner layer target and the first window 21.

[0076] It is understandable that in actual application, the graphic production processes provided in Example 1 and Example 2 may be used in combination.

[0077] Note: In addition to the above differences, the laminate 1 structure, layer-adding processing method, alignment method, laser groove burning method, etc. used in this embodiment 2 can all adopt the same technical means as in embodiment 1, so they will not be described here.

[0078] Embodiment 3:

[0079] This embodiment 3 provides a substrate with a non-metallized step blind groove, which is manufactured by using the processing method of the substrate with a non-metallized step blind groove described in the above embodiment 1.

[0080] Specifically, the specific structure of the substrate described in this embodiment 3 is: Figure 8As shown, the substrate includes a main body, and the main body includes an insulating substrate 12, an inner copper foil 11, an outer copper foil 10, an insulating build-up layer 30 and a copper foil build-up layer 31 which are stacked in sequence. The outer copper foil 10 is provided with an inner layer circuit 20, and the copper foil build-up layer 31 is provided with an outer layer circuit 8. In particular, the main body is also provided with a non-metallic step blind groove 9 which opens to the copper foil build-up layer 31 and takes the insulating substrate 12 as the bottom of the groove, that is, the inner side wall of the non-metallic step blind groove 9 is stepped, and the step portion on the inner side wall of the non-metallic step blind groove 9 (see Figure 8 The circled part in the figure is also insulating.

[0081] From the above, it can be seen that the substrate described in this embodiment 3 has high dimensional accuracy and good appearance quality, which well meets the production needs in the field of circuit boards.

[0082] Finally, the prefixes "first", "second", etc. (such as the first window, the second window, etc.) in the component names in this application specification are only for the convenience of description and are not used to limit the scope of implementation of the patent of this invention.

[0083] Many specific details are described in the above description to facilitate a full understanding of the present invention. However, the above description is only a preferred embodiment of the present invention. The present invention can be implemented in many other ways different from those described herein, so the present invention is not limited to the specific implementation disclosed above. At the same time, any person familiar with the art can make many possible changes and modifications to the technical solution of the present invention using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A method for processing a substrate having a non-metallized step blind groove, characterized in that: include: A laminated board (1) is provided, wherein the laminated board (1) is provided with an outer copper foil (10) located at the outermost side and an inner copper foil (11) located inside the outer copper foil (10); While producing an inner layer circuit (20) and an inner layer target on the outer layer copper foil (10) by using a pattern production process, a first window (21) is also produced on a preset area of ​​the outer layer copper foil (10); Adding layers to the laminated board (1) on which the pattern is completed, so as to sequentially stack an insulating add-on layer (30) and a copper foil add-on layer (31) on the outer copper foil (10); A window is opened in a preset area of ​​the copper foil build-up layer (31) by grabbing the inner layer target for alignment to obtain a second window (4), wherein the second window (4) is aligned with the first window (21) in the thickness direction of the laminate (1), and the alignment degree is controlled to be less than 10 μm, and the area of ​​the second window (4) is greater than that of the first window (21); Laser grooves are sequentially burned based on the second window (4) and the first window (21) to obtain a first-order blind groove (5) with the second window (4) as the groove opening and a part of the outer copper foil (10) as the groove bottom, and a second-order blind groove (6) with the first window (21) as the groove opening and a part of the inner copper foil (11) as the groove bottom; the second-order blind groove (6) is connected with the first-order blind groove (5) and together forms a stepped blind groove (7); While the outer layer circuit (8) is produced on the copper foil build-up layer (31) by using a pattern production process, the bottoms of the first-order blind groove (5) and the second-order blind groove (6) are removed to produce a non-metallized step blind groove (9), thereby producing a substrate having the non-metallized step blind groove (9).

2. The method for processing a substrate having a non-metallized step blind groove according to claim 1, characterized in that: The board obtained by sequentially performing pattern making and layer adding on the laminated board (1) is defined as a first intermediate board; The manufacturing method of the second window (4) is as follows: firstly, laser processing is performed on the first intermediate plate to expose the inner layer target; then, a window is opened in a preset area of ​​the copper foil build-up layer (31) by using a pattern manufacturing process, and during the window opening process, the inner layer target is grasped for alignment, so that the alignment degree between the obtained second window (4) and the first window (21) is controlled to be less than 10 μm.

3. The method for processing a substrate having a non-metallized step blind groove according to claim 2, characterized in that: The pattern production process includes pre-filming treatment, anti-corrosion photosensitive film coating, exposure, development, etching and film stripping.

4. The method for processing a substrate having a non-metallized step blind groove according to claim 2, characterized in that: The pattern production process includes pre-filming treatment, anti-plating photosensitive film coating, exposure, development, pattern electroplating, film stripping, baking and flash etching.

5. The method for processing a substrate having a non-metallized step blind groove according to claim 1, characterized in that: The horizontal distance between the inner wall of the second window (4) and the inner wall of the first window (21) is not less than 75 μm.

6. The method for processing a substrate having a non-metallized step blind groove according to claim 1, characterized in that: The processing parameters of the laser groove burning are: mask thickness is 1.8-2.1mm, laser pulse width is 5-8μs, laser energy is 3.2-8.5MJ, laser shot number is 2-8 shots, laser groove wall slope is ≤15μm, and groove wall roughness is ≤15μm.

7. The method for processing a substrate having a non-metallized step blind groove according to claim 5, characterized in that: The horizontal distance between the inner side wall of the first-order blind groove (5) and the inner side wall of the second-order blind groove (6) is not less than 75 μm.

8. The method for processing a substrate having a non-metallized step blind groove according to claim 1, characterized in that: The insulating layer (30) is made of a prepreg or pure glue material.

9. A substrate having a non-metallized step blind groove, characterized in that: The substrate is manufactured by the processing method of the substrate with non-metallized step blind groove as described in any one of claims 1 to 8.

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