A manufacturing method of a high-precision stepped circuit board and a high-precision stepped circuit board

Abstract

The present invention provides a manufacturing method of a high-precision stepped circuit board and a high-precision stepped circuit board, belonging to the technical field of circuit board manufacturing, and solving the problems of low production efficiency and poor product performance and quality of high-precision stepped circuit boards. The method includes: providing a first substrate and a second substrate; performing a first pretreatment on the first substrate to obtain a first substrate to be laminated, the first substrate having a routing groove position; performing a second pretreatment on the second substrate to obtain a second substrate to be laminated; performing a lamination treatment on the first substrate to be laminated and the second substrate to be laminated to obtain a laminated substrate with steps; performing a third pretreatment on the laminated substrate with steps to obtain a substrate after the third pretreatment; performing a shaping treatment on the substrate after the third pretreatment to obtain a high-precision stepped circuit board. This solution realizes the efficient production and manufacturing of high-precision stepped circuit boards by first manufacturing the circuit board in layers and then performing lamination and shaping treatments, improving the product performance and quality.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board manufacturing, and particularly to a manufacturing method of a high-precision stepped circuit board and a high-precision stepped circuit board. Background Art

[0002] In recent years, with the development of electronic products towards multi-functionality, miniaturization, and light weight, the market demand for high-end key printed circuit board products such as high-frequency and high-speed, high-layer and high-density printed circuit boards, integrated circuit packaging substrates, and special printed circuit boards has been continuously increasing. At the same time, for higher-density integrated and more miniaturized electronic devices, more electronic components need to be integrated within a limited space, which not only promotes the reduction of device size but also poses higher requirements for realizing more functions and more complex circuit designs within a limited area.

[0003] However, currently, when manufacturing stepped circuit boards, it is easy to produce overflow glue, which in turn contaminates the circuits in the ladder grooves, resulting in low production efficiency and poor product performance and quality of high-precision stepped circuit boards. Summary of the Invention

[0004] The present invention provides a manufacturing method of a high-precision stepped circuit board and a high-precision stepped circuit board, which solves the problems of low production efficiency and poor product performance and quality of high-precision stepped circuit boards.

[0005] To solve the above technical problems, the technical solution of the present invention is as follows:

[0006] An embodiment of the present invention provides a manufacturing method of a high-precision stepped circuit board, including:

[0007] Providing a first substrate and a second substrate;

[0008] Performing a first pretreatment on the first substrate to obtain a first substrate to be laminated, the first substrate having a routing groove position;

[0009] Performing a second pretreatment on the second substrate to obtain a second substrate to be laminated;

[0010] Performing a lamination process on the first substrate to be laminated and the second substrate to be laminated to obtain a laminated substrate with steps, the routing groove position being adhered to the second substrate;

[0011] Performing a third pretreatment on the laminated substrate with steps to obtain a substrate after the third pretreatment;

[0012] Performing a shaping process on the substrate after the third pretreatment to obtain a high-precision stepped circuit board.

[0013] Optionally, performing a first pretreatment on the first substrate to obtain a first substrate to be laminated includes:

[0014] Cut the first substrate according to the first preset cutting parameters to obtain the first substrate after blanking;

[0015] Drill the first substrate after blanking to obtain the first substrate after drilling;

[0016] Perform plate grinding, film laminating, exposure and development on the first substrate after drilling to obtain the first substrate with an anti-corrosion protection layer formed;

[0017] Perform etching and stripping on the first substrate with the anti-corrosion protection layer formed to obtain the first substrate with circuits formed;

[0018] Perform adhesive film pasting on the first substrate with circuits formed to obtain the first substrate with an adhesive film pasted;

[0019] Perform slot milling on the first substrate with the adhesive film pasted to obtain the first substrate to be laminated;

[0020] Optionally, perform a second pre-treatment on the second substrate to obtain the second substrate to be laminated, including:

[0021] Cut the second substrate according to the second preset cutting parameters to obtain the second substrate after blanking;

[0022] Drill the second substrate after blanking to obtain the second substrate after drilling;

[0023] Perform plate grinding, film laminating, exposure and development on the second substrate after drilling to obtain the second substrate with an anti-corrosion protection layer formed;

[0024] Perform etching and stripping on the second substrate with the anti-corrosion protection layer formed to obtain the second substrate to be laminated;

[0025] Optionally, perform a lamination process on the first substrate to be laminated and the second substrate to be laminated to obtain a laminated substrate with steps, including:

[0026] Brown the second substrate to be laminated to obtain the browned second substrate;

[0027] Perform overlay riveting on the browned second substrate and the slot milled position of the first substrate to obtain the riveted substrate;

[0028] Perform a lamination process on the riveted substrate to obtain a laminated substrate with steps.

[0029] Optionally, perform a third pre-treatment on the laminated substrate with steps to obtain the substrate after the third pre-treatment, including:

[0030] The pressed substrate is drilled to obtain a drilled substrate;

[0031] The drilled substrate is subjected to electroless copper plating to obtain a substrate after electroless copper plating;

[0032] The substrate after electroless copper plating is subjected to panel plating to obtain a substrate after panel plating;

[0033] The substrate after panel plating is subjected to copper cladding etching to obtain a substrate after the third pretreatment.

[0034] Optionally, subjecting the substrate after panel plating to copper cladding etching to obtain a substrate after the third pretreatment includes:

[0035] The substrate after panel plating is subjected to board grinding, film laminating, exposure and development to obtain a substrate with an anti-etching protective layer formed;

[0036] The substrate with the anti-etching protective layer formed is subjected to micro-etching to obtain a substrate with circuits formed;

[0037] The substrate with circuits formed is subjected to film stripping to obtain a substrate after film stripping;

[0038] The substrate after film stripping is subjected to electroplating etching to obtain a substrate after the third pretreatment.

[0039] Optionally, subjecting the substrate after film stripping to electroplating etching to obtain a substrate after the third pretreatment includes:

[0040] The substrate after film stripping is subjected to board grinding, film laminating, exposure and development to obtain a substrate with an anti-etching protective layer formed;

[0041] The substrate with the anti-etching protective layer formed is subjected to graphic electroplating to obtain a substrate after graphic electroplating;

[0042] The substrate after graphic electroplating is subjected to etching to obtain a substrate after the third pretreatment.

[0043] Optionally, subjecting the substrate after the third pretreatment to shaping to obtain a high-precision stepped circuit board includes:

[0044] The substrate after the third pretreatment is subjected to optical inspection to obtain a substrate after optical inspection;

[0045] The substrate after optical inspection is subjected to solder mask and legend processing to obtain a substrate after solder mask and legend processing;

[0046] The substrate after solder mask and legend processing is subjected to surface immersion gold treatment to obtain a substrate after surface immersion gold treatment;

[0047] The substrate after surface immersion gold is cut and formed to obtain a high-precision stepped circuit board.

[0048] Optionally, the method for manufacturing the highly integrated half-hole stepped circuit board further includes:

[0049] The high-precision stepped circuit board is tested and inspected according to preset test conditions to obtain a qualified high-precision stepped circuit board; the preset test conditions include at least one of the following conditions:

[0050] Open circuit and short circuit test conditions, with a test voltage of 20 - 500V, a test current of 5 - 200mA, a conduction test range of 2 - 10000 ohm, an insulation test range of 5 - 500 Mohm, an equivalent test range of 0.1 pF - 10 mF, and an ambient temperature of 22°C - 26°C.

[0051] An embodiment of the present invention also provides a high-precision stepped circuit board, which is prepared by the above method.

[0052] The technical solution of the present invention has at least the following effects:

[0053] The above solution of the present invention provides a first substrate and a second substrate; performs a first pretreatment on the first substrate to obtain a first substrate to be laminated; performs a second pretreatment on the second substrate to obtain a second substrate to be laminated; laminates the first substrate to be laminated and the second substrate to be laminated to obtain a laminated substrate; performs a third pretreatment on the laminated substrate to obtain a substrate after the third pretreatment; and performs a forming process on the substrate after the third pretreatment to obtain a high-precision stepped circuit board. This solution realizes the efficient production and manufacturing of high-precision stepped circuit boards by first manufacturing the circuit boards in layers and then performing lamination and forming processes, improving the product performance and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a flowchart of the method for manufacturing a high-precision stepped circuit board provided by an embodiment of the present invention;

[0055] Figure 2 is a cross-sectional view of a high-precision stepped circuit board provided by an embodiment of the present invention;

[0056] Among them, 1, first substrate; 2, second substrate; 3, first circuit layer; 4, via hole; 5, AD adhesive film layer; 6, second circuit layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0057] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be completely conveyed to those skilled in the art.

[0058] As Figure 1 shown, an embodiment of the present invention provides a method for manufacturing a high-precision stepped circuit board, including:

[0059] Step 11: Provide a first substrate and a second substrate;

[0060] Step 12: Perform a first pretreatment on the first substrate to obtain a first substrate to be laminated, and the first substrate has a routing groove position;

[0061] Step 13: Perform a second pretreatment on the second substrate to obtain a second substrate to be laminated;

[0062] Step 14: Perform a lamination process on the first substrate to be laminated and the second substrate to be laminated to obtain a laminated substrate with steps, and the routing groove position is attached to the second substrate;

[0063] Step 15: Perform a third pretreatment on the laminated substrate with steps to obtain a substrate after the third pretreatment;

[0064] Step 16: Perform a shaping process on the substrate after the third pretreatment to obtain a high-precision stepped circuit board.

[0065] In this example, two substrates are first prepared as the basic materials for manufacturing the circuit board. These substrates are usually composed of insulating materials such as epoxy resin and fiberglass to meet the subsequent circuit design and functional requirements. Among them, the materials of the first substrate and the second substrate are the same; according to the design requirements, the thickness and size can be different. For example, the thickness of the first substrate is 3 mm, and the thickness of the second substrate is 2 mm; the pretreatment steps are to ensure that the surface of the substrate is clean, flat, and has good adhesiveness. Specifically, it includes steps such as cutting, drilling positioning holes, forming an anti-etching layer, etching, pasting a film, and routing slots. After these pretreatment steps, the first substrate is ready for the subsequent lamination operation; similar to the first substrate, the second substrate also needs to go through the pretreatment steps to ensure that its surface is clean, flat, and has good adhesiveness; after pretreatment, the first substrate and the second substrate can be laminated; during the lamination process, the pretreated first substrate and the second substrate are first tightly bonded together through a lamination device; after lamination, a third pretreatment is still required, specifically including steps such as drilling positioning holes, electroless copper plating, full-panel electroplating, and etching to form a copper layer on the surface of the substrate to meet the conductivity requirements of the circuit design; then the substrate after the third pretreatment is processed into the final required shape and size, including steps such as cutting and grinding. After the forming process, the final high-precision stepped circuit board is obtained.

[0066] Through the above technical solution of the present invention, by first manufacturing the circuit board in layers and then performing lamination and forming processes, the problems of low production efficiency and poor product performance and quality of the high-precision stepped circuit board are solved, realizing the efficient production and manufacturing of the high-precision stepped circuit board and improving the product performance and quality.

[0067] In an optional embodiment proposed by the present invention, step 12 may include:

[0068] Step 121, cutting the first substrate according to the first preset cutting parameters to obtain the first substrate after blanking;

[0069] Step 122, drilling the first substrate after blanking to obtain the first substrate after drilling;

[0070] Step 123, performing plate grinding, film pressing, exposure, and development on the first substrate after drilling to obtain the first substrate with an anti-etching protection layer formed;

[0071] Step 124, performing etching and stripping on the first substrate with the anti-etching protection layer formed to obtain the first substrate with circuits formed;

[0072] Step 125, performing film pasting on the first substrate with circuits formed to obtain the first substrate with a film pasted;

[0073] Step 126: Perform a grooving process on the first substrate with the adhesive film attached to obtain the first substrate to be laminated.

[0074] In this example, first, the first substrate is cut according to the first preset cutting parameters to obtain the first substrate after blanking; specifically, a saw blade type blanking machine is used for blanking under the conditions that the blanking speed is 4.5 ± 0.5 m / min and the blanking size tolerance is controlled within ±0.1 mm; after blanking, the blanked first substrate is drilled to obtain the first substrate after drilling; specifically, a drill bit, backing plate, and aluminum sheet are used for drilling under the conditions that the workshop environment temperature is 20 ± 2°C and the number of times of drill bit grinding does not exceed 5 times. The drilled positioning holes are used for laminating and fixing the first substrate and the second substrate; the drilled first substrate is subjected to plate grinding - film pressing - exposure - development to obtain the first substrate with an anti - corrosion protection layer formed, and the main parameters include: the plate grinding speed in the pretreatment is 2.0 ± 0.5 m / min, the pickling concentration is 3% - 5%, the drying temperature is 90 ± 5°C, and the water break test is not less than 15 s; the dry film laminating speed is 0.9 ± 0.2 m / min, the dry film laminating temperature is 120 ± 10°C, the dry film laminating pressure is 60 - 80 Psi, the laminating inlet plate temperature is 50 ± 5°C, the laminating outlet plate temperature is 55 ± 5°C, the exposure scale is 6 - 7 levels, the LDI exposure energy is 24.3 MJ, the clean room environment temperature is 20 ± 2°C, the humidity is 55% ± 5%, the dry film development speed is 2.5 ± 0.5 m / min, the dry film development temperature is 30 ± 2°C, the concentration of sodium carbonate developer is 1.0% ± 0.2%, and the development pressure is controlled at 60% - 70% according to the development point;

[0075] After the above - mentioned treatment, an anti - corrosion protection layer reflecting the circuit contour is formed on the first substrate; then, the first substrate with the anti - corrosion protection layer formed is subjected to etching and film stripping treatment to obtain the first substrate with the circuit formed. The specific parameters of the etching and film stripping are shown in Table 1;

[0076] Table 1 Etching and Film Stripping Parameters

[0077]

[0078] After obtaining the first substrate on which the circuit is formed, in order to prevent poor glue overflow during the bonding of the first substrate and the second substrate, it is designed to stick an AD glue film on the surface of the first substrate that fits the second substrate, that is, cut the AD glue film according to the size of the first substrate, then lay the AD glue film on the core board, and finally use a laminating machine to press the film tightly on the core board; the laminating parameters include: the temperature of the hot pressing roller is 125±5°C, and the speed of the hot pressing roller is 3.0±0.5 m / min; after sticking the AD glue film, use a routing machine to route the groove positions on the first substrate corresponding to the positions where the second substrate is designed to be exposed, so as to obtain the first substrate to be laminated. Among them, the parameters during grooving include: the feed speed is 10±5 m / min, the cutting speed is 5±2 m / min, and the rotation speed is 48000 - 51000 rpm; the workshop ambient temperature is 23±3°C, and the humidity is 60%±10%.

[0079] In an optional embodiment proposed by the present invention, step 13 may include:

[0080] Step 131, perform cutting processing on the second substrate according to the second preset cutting parameters to obtain the second substrate after blanking;

[0081] Step 132, perform drilling processing on the second substrate after blanking to obtain the second substrate after drilling;

[0082] Step 133, perform plate grinding, film pressing, exposure and development processing on the second substrate after drilling to obtain the second substrate on which the anti-corrosion protection layer is formed;

[0083] Step 134, perform etching and film stripping processing on the second substrate on which the anti-corrosion protection layer is formed to obtain the second substrate to be laminated.

[0084] In this example, first, the second substrate is cut according to the second preset cutting parameters to obtain the second substrate after blanking. Specifically, a saw blade type blanking machine is used for blanking under the conditions that the blanking speed is 4.5 ± 0.5 m / min and the blanking dimension tolerance is controlled within ±0.1 mm. After blanking, the second substrate after blanking is drilled to obtain the second substrate after drilling. Specifically, a drill bit, a backing plate, and an aluminum sheet are used for drilling under the conditions that the workshop environment temperature is 20 ± 2 °C and the number of times of drill bit grinding does not exceed 5 times. The located holes drilled are used for laminating and fixing the first substrate and the second substrate. The second substrate after drilling is subjected to plate grinding - film laminating - exposure - development treatment to obtain the second substrate with an anti - corrosion protection layer formed. The main parameters include: the plate grinding speed in the pretreatment is 2.0 ± 0.5 m / min, the pickling concentration is 3% - 5%, the drying temperature is 90 ± 5 °C, and the water break test is not less than 15 s; the dry film laminating speed is 0.9 ± 0.2 m / min, the dry film laminating temperature is 120 ± 10 °C, the dry film laminating pressure is 60 - 80 Psi, the laminating inlet plate temperature is 50 ± 5 °C, the laminating outlet plate temperature is 55 ± 5 °C, the exposure scale is 6 - 7 levels, the LDI exposure energy is 24.3 MJ, the clean room environment temperature is 20 ± 2 °C, the humidity is 55% ± 5%, the dry film development speed is 2.5 ± 0.5 m / min, the dry film development temperature is 30 ± 2 °C, the concentration of sodium carbonate developer is 1.0% ± 0.2%, and the development pressure is controlled at 60% - 70% according to the development points. After the above - mentioned treatment, an anti - corrosion protection layer reflecting the circuit contour is formed on the second substrate. Then, the second substrate with the anti - corrosion protection layer formed is subjected to etching and stripping treatment to obtain the second substrate to be laminated. It should be noted that the method for determining the time of the etching and stripping treatment here is the same as that for the first substrate. According to the ambient temperature of the substrate during etching, the copper thickness of the circuit on the substrate, the actual line width of the actual circuit, the etching rate, and the side - etching effect, the time of the etching and stripping treatment is determined;

[0085] In specific implementation, the copper thickness of the circuit on the substrate is usually in ounces, and 1 oz copper thickness is about 35 μm; the actual line width of the actual circuit refers to the actual width of the designed specified circuit width after considering etching; the side - etching effect refers to the phenomenon that the side of the copper layer may be etched during the etching process, which will cause the line width to become narrower;

[0086] The theoretical etching and stripping treatment time is: , where t1 is the theoretical etching time, L is the copper thickness of the circuit on the substrate, V is the etching rate, and the etching rate is a preset value;

[0087] The actual line width of the actual circuit can be obtained by the following formula: K = K1 – 2×K s , where K is the actual line width of the actual circuit, K1 is the designed line width of the circuit, K sis the lateral etching amount, which is generally 10% - 20% of the etching depth, and is taken as 15% in this formula;

[0088] From this, the actual etching and stripping treatment time can be obtained as

[0089]

[0090] where m T is the environmental temperature influence coefficient. Under normal circumstances, within the range of 40°C - 50°C for the etching temperature, when the environmental temperature is relatively high, the activity of the etching solution increases, the etching rate accelerates, and the etching time shortens; while when the temperature is relatively low, the activity of the etching solution weakens, the etching rate slows down, and the etching time prolongs; therefore, it can be set as , where T is the etching environmental temperature.

[0091] In an optional embodiment proposed by the present invention, step 14 may include:

[0092] Step 141, perform browning treatment on the second substrate to be laminated, obtaining the browned second substrate;

[0093] Step 142, perform lamination and riveting treatment on the grooved positions of the browned second substrate and the first substrate, obtaining the laminated and riveted substrate;

[0094] Step 143, perform lamination treatment on the laminated and riveted substrate, obtaining the laminated substrate with steps.

[0095] In this example, first, thoroughly clean the second substrate to remove impurities such as oil stains and dust on the surface, ensuring that the browning solution can contact the substrate surface evenly and sufficiently; immerse the cleaned second substrate in a solution containing a browning agent; the browning agent is usually a strong oxidant that can undergo a chemical reaction on the surface of the second substrate to form a rough oxide film; by controlling parameters such as the soaking time, temperature, and concentration of the browning solution, the thickness and roughness of the browning layer can be adjusted to meet the requirements of subsequent processes; after the browning treatment, take out the second substrate from the browning solution, clean it with a cleaning agent such as deionized water to remove the residual browning solution and impurities, and then perform a drying treatment to obtain the browned second substrate;

[0096] Align the browned second substrate and the first substrate according to the predetermined position and direction to ensure precise matching between layers; insert the rivets into the riveting holes and use riveting equipment to perform press-riveting on the rivets; during the press-riveting process, the tail of the rivet will undergo plastic deformation and thus be firmly fixed on the substrate; thereby making the first substrate 1 with grooved positions and the second substrate 2 fit together to form a substrate with steps having a step height difference; inspect the laminated and riveted substrate to ensure that the riveting quality meets the requirements; if necessary, perform trimming treatment on uneven or protruding parts;

[0097] Put the substrate after laminating and riveting into a laminator for preheating treatment; Preheating can remove moisture and volatile substances in the substrate and improve the lamination effect; After preheating, apply a certain pressure and temperature to the substrate; The magnitude of the pressure and temperature should be adjusted according to factors such as the material, number of layers, and thickness of the substrate; Through heating and pressurization, the adhesive between the substrates undergoes a curing reaction, thereby achieving a firm bond; After applying pressure and temperature, maintain a certain heat preservation time to ensure that the adhesive is fully cured; After the heat preservation ends, perform a cooling treatment to gradually reduce the substrate to room temperature; Inspect the laminated substrate to ensure that the layers are firmly bonded and there are no obvious defects; The specific parameters of the lamination process are shown in Table 2.

[0098] Table 2 Lamination Process Parameters

[0099]

[0100] In an optional embodiment proposed by the present invention, step 15 may include:

[0101] Step 151, perform drilling treatment on the laminated substrate to obtain a drilled substrate;

[0102] Step 152, perform copper deposition treatment on the drilled substrate to obtain a substrate after copper deposition;

[0103] Step 153, perform panel plating treatment on the substrate after copper deposition to obtain a substrate after panel plating;

[0104] Step 154, perform copper cladding etching treatment on the substrate after panel plating to obtain a substrate after the third pretreatment.

[0105] In this example, first perform drilling treatment on the laminated substrate to form positioning holes for installing components on the substrate. Specifically, use a drill bit, backing plate, and aluminum sheet to perform drilling under the conditions that the workshop environment temperature is 20 ± 2 °C and the number of times the drill bit is ground does not exceed 5 times;

[0106] Perform copper deposition treatment on the drilled substrate, that is, deposit a layer of metallic copper on the surface of the hole or the position of the board surface substrate by chemical means to provide a bottom copper for increasing the copper thickness in subsequent electroplating, and finally achieve the conductive and heat dissipation functions required by the product; The steps of copper deposition treatment include: loading the board - swelling - water washing - degumming - recovery - water washing - pre-neutralization - high-level water washing - neutralization - water washing - degreasing - hot water washing - water washing - micro-etching - water washing - pre-immersion - activation - water washing - acceleration - water washing - copper deposition - water washing - unloading the board;

[0107] Perform panel plating treatment on the substrate after copper deposition to increase the thickness of the copper deposition layer; The steps of panel plating treatment include: loading the board - pickling - double water washing - pre-immersion - copper plating - double water washing - unloading the board - stripping and hanging - water washing - clamping head brushing and drying - unloading the board;

[0108] After the substrate is electroplated, copper plating etching treatment is carried out, which specifically includes: first, grinding the board - laminating - exposing - developing to form an anti-etching protective layer on the substrate, exposing the positions of the copper layers that are not needed, and protecting the positions of the copper layers that are needed. The unnecessary copper layers are removed by chemical micro-etching, leaving the positions of the copper layers that are needed; the steps of micro-etching include placing the board on the horizontal line - water washing - micro-etching - water washing - strong air drying. The main parameters of micro-etching include a micro-etching speed of 1.1 m / min, a micro-etching solution temperature of 35 ± 5 °C, a sulfuric acid concentration of 150 - 200 g / L, and a hydrogen peroxide concentration of 40 - 80 ml / L;

[0109] After the substrate is micro-etched, the anti-etching dry film (i.e., the anti-etching protective layer) needs to be removed to expose the copper layers that are needed; the steps of film removal include placing the board on the horizontal line - film removal - water washing - strong air drying - high-temperature drying; the main parameters include a micro-etching speed of 2.5 m / min, a film removal solution temperature of 40 ± 5 °C, and a film removal solution concentration of 5 ± 2% sodium hydroxide;

[0110] After the film is removed from the substrate, graphic circuit processing and graphic electroplating processing are carried out in sequence, that is, by means of exposure - development, an anti-etching protective layer is formed on the substrate, exposing the positions of the copper layers that are not needed, protecting the positions of the copper layers that are needed, then the thickness of the copper layers on the hole walls and the substrate is increased by electroplating, and then etching is carried out again. For the unnecessary copper layers, the unnecessary copper layers are removed by chemical means, leaving the graphic circuit copper layers that are needed, and finally the third pre-treated substrate is obtained.

[0111] In an optional embodiment proposed by the present invention, step 16 may include:

[0112] Step 161, optically inspecting the third pre-treated substrate to obtain the substrate after optical inspection;

[0113] Step 162, performing solder mask text processing on the substrate after optical inspection to obtain the substrate after solder mask text processing;

[0114] Step 163, performing surface immersion gold treatment on the substrate after solder mask text processing to obtain the substrate after surface immersion gold treatment;

[0115] Step 164, performing cutting and shaping processing on the substrate after surface immersion gold treatment to obtain a high-precision stepped circuit board.

[0116] In this example, first, the production board is optically inspected to collect the image of the production board, and then it is checked according to the design data to detect whether there are PCB defects such as circuit gaps, open circuits, thin lines, thick lines, etc. on the production board. Then, the substrate after electroplating and etching treatment is subjected to solder mask text treatment to obtain the substrate after solder mask text treatment. Among them, the main materials for solder mask treatment include solder mask ink, thinner, industrial sodium carbonate, and industrial sulfuric acid. The main parameters include the pre-treatment grinding speed of 1.5 ± 0.5 m / min, the pickling concentration of 3% - 5%, the drying temperature of 90 ± 5 °C, and the printing speed of 1.5 ± 0.5 m / min. The main materials for text treatment include character ink and spray printing cleaning solution. The substrate after solder mask text treatment is subjected to surface immersion gold treatment to obtain the substrate after surface immersion gold treatment. Among them, the main materials for surface treatment include gold salt, activation, pre-immersion, and sulfuric acid. The main parameters include the degreasing temperature of 40 - 60 °C, the degreasing concentration of 20 - 120 ml / L, sodium persulfate of 80 - 13 g / L, sulfuric acid of 10 - 30 ml / L, the micro-etching temperature of 28 - 32 °C, the activation temperature of 25 - 30 °C, the activation concentration of 80 - 120 ml / L, the electroless nickel temperature of 79 - 81 °C, the nickel bath concentration of 4.3 - 4.6 g / L, the bath load of 0.3 - 1.0 d㎡ / L, the PH of 4.5 - 4.7, the immersion gold temperature of 85 - 90 °C, the PH of 4.8 - 6.0, the gold concentration of 0.5 - 1.2%, and the gold solution concentration of 100 ml / L.

[0117] A specific embodiment of the method for manufacturing a high-precision stepped circuit board provided by the embodiment of the present invention is as follows:

[0118] Step 1, provide a first substrate and a second substrate;

[0119] First, prepare two substrates, namely the first substrate and the second substrate. The materials of both substrates are epoxy boards (FR-4);

[0120] Step 2, perform a first pre-treatment on the first substrate to obtain the first substrate to be laminated;

[0121] Specifically, a saw blade type cutting machine is used to perform cutting under the conditions that the cutting speed is 4.5±0.5 m / min and the cutting size tolerance is controlled within ±0.1 mm; after cutting, for the first substrate after cutting, a drill bit, a backing plate, and an aluminum sheet are used to drill positioning holes under the conditions that the workshop environment temperature is 20±2 °C and the number of times of drill bit grinding does not exceed 5 times. These positioning holes are used for precise positioning and fixing when the first substrate and the second substrate are laminated; the drilled first substrate is subjected to plate grinding - film pressing - exposure - developing treatment to form an anti-corrosion protection layer reflecting the circuit contour on the first substrate; then the first substrate with the anti-corrosion protection layer formed is subjected to etching and film stripping treatment to obtain the first substrate with the circuit formed; in order to prevent poor glue overflow when the first substrate and the second substrate are combined, an AD adhesive film is designed to be pasted on the surface of the first substrate that fits with the second substrate; after pasting the AD adhesive film, a router is used to route a groove position on the first substrate corresponding to the position area exposed outside the second substrate design to obtain the first substrate to be laminated.

[0122] Step 3, perform a second pretreatment on the second substrate to obtain a second substrate to be laminated.

[0123] Specifically, a saw blade type cutting machine is used to perform cutting under the conditions that the cutting speed is 4.5±0.5 m / min and the cutting size tolerance is controlled within ±0.1 mm; after cutting, for the second substrate after cutting, a drill bit, a backing plate, and an aluminum sheet are used to drill positioning holes under the conditions that the workshop environment temperature is 20±2 °C and the number of times of drill bit grinding does not exceed 5 times. These positioning holes are used for precise positioning and fixing when the first substrate and the second substrate are laminated; the drilled second substrate is subjected to plate grinding - film pressing - exposure - developing treatment to form an anti-corrosion protection layer reflecting the circuit contour on the second substrate; then the second substrate with the anti-corrosion protection layer formed is subjected to etching and film stripping treatment to obtain the second substrate to be laminated.

[0124] Step 4, perform a lamination treatment on the first substrate to be laminated and the second substrate to be laminated to obtain a laminated substrate.

[0125] Specifically, first, the second substrate is thoroughly cleaned to remove impurities such as oil stains and dust on the surface; the cleaned second substrate is immersed in a solution containing a brownification agent for brownification treatment, then the second substrate is taken out of the brownification solution and cleaned with a cleaning agent such as deionized water to remove the residual brownification solution and impurities, and then dried to obtain the brownified second substrate; the brownified second substrate and the first substrate are aligned according to a predetermined position and direction to ensure precise matching between layers; rivets are inserted into the riveting holes, and a riveting device is used to perform riveting on the rivets; the laminated substrate after riveting is placed in a laminator for preheating treatment; after preheating, a certain pressure and temperature are applied to the substrate to cause the adhesive between the substrates to undergo a curing reaction, thereby achieving a firm bond.

[0126] Step 5, perform a third pre-treatment on the pressed substrate to obtain a substrate after the third pre-treatment;

[0127] Specifically, first drill the pressed substrate to form positioning holes for mounting components on the substrate; perform copper deposition on the drilled substrate, and deposit a layer of metallic copper on the surface of the holes or on the substrate surface base material by chemical means to provide a bottom copper for increasing the copper thickness in subsequent electroplating; after copper deposition, perform panel electroplating on the substrate to increase the thickness of the copper deposition layer; perform copper cladding etching on the panel-electroplated substrate, including: first perform grinding - laminating - exposure - development to form an anti-etching protective layer on the substrate, which will expose the positions of the copper layers that are not needed while protecting the positions of the copper layers that are needed, and remove the copper layers that are not needed by chemical micro-etching, leaving the positions of the copper layers that are needed; after the substrate has been micro-etched, the anti-etching dry film (i.e., the anti-etching protective layer) needs to be removed, so as to expose the copper layers that are needed; after film removal, perform pattern circuit processing and pattern electroplating on the substrate in sequence, that is, by exposure - development, form an anti-etching protective layer on the substrate, expose the positions of the copper layers that are not needed, protect the positions of the copper layers that are needed, then increase the thickness of the copper layers on the hole walls and the substrate by electroplating, and then perform etching again. For the copper layers that are not needed, remove the copper layers that are not needed by chemical means, leaving the copper layers of the required pattern circuit, and finally obtain a substrate after the third pre-treatment.

[0128] Step 6, perform a shaping process on the substrate after the third pre-treatment to obtain a high-precision stepped circuit board.

[0129] Specifically, first perform an optical inspection on the production board to check whether there are any defective defects on the production board; then perform solder mask text processing on the substrate after the electroplating etching treatment to obtain a substrate after solder mask text processing. Among them, the solder mask layer is usually a special ink or resin material used to protect the non-conductive areas of the circuit board and prevent short circuits or damage during subsequent soldering; after the solder mask layer is dried and cured, text printing is performed; text printing usually includes markings, component numbers, polarity markings, etc. on the circuit board, which are used to guide subsequent assembly and testing; perform surface immersion gold treatment on the substrate after the solder mask text processing to obtain a substrate after surface immersion gold treatment. Among them, immersion gold is a chemical gold plating method, and a thin layer of gold is deposited on the substrate surface through a chemical reaction; this layer of gold not only has good electrical conductivity and corrosion resistance, but also provides an aesthetic appearance; after immersion gold is completed, perform post-treatment, including cleaning, drying and other steps to remove all residues and ensure the firm adhesion of the gold layer; use equipment such as a laser cutting machine, mechanical punch or water jet to cut and shape the substrate according to the cutting program to obtain a high-precision stepped circuit board.

[0130] Through the above technical solution of the present invention, by first fabricating the circuit board in layers and then performing lamination and shaping processes, the efficient production of high-precision stepped circuit boards is achieved, improving the product performance and quality, realizing the efficient production of high-precision stepped circuit boards, and improving the product performance and quality.

[0131] In an alternative embodiment of the present invention, the method further includes the following steps:

[0132] Step 171, testing and inspecting the high-precision stepped circuit board according to preset test conditions to obtain a qualified high-precision stepped circuit board; the preset test conditions include at least one of the following conditions:

[0133] Step 172, open circuit and short circuit test conditions, the test voltage is 20~500V, the test current is 5~200mA, the conduction test range is 2~10000ohm, the insulation test range is 5~500Mohm, the equivalent test range is 0.1pF~10mF, and the ambient temperature is 22℃~26℃.

[0134] In this embodiment, in order to improve the qualification rate of the circuit board and user satisfaction, it is necessary to inspect the high-precision stepped circuit board. Only the circuit board that passes the preset inspection conditions is a qualified high-precision stepped circuit board, which can be used for subsequent production or factory shipment. In this embodiment, after the high-precision stepped circuit board is inspected according to the above inspection method, the qualification rate of the high-precision stepped circuit board product is relatively high, fully meeting the market demand.

[0135] As Figure 2 shown, an embodiment of the present invention provides a high-precision stepped circuit board, which is prepared by using the manufacturing method of the high-precision stepped circuit board described in any one of the above embodiments. The high-precision stepped circuit board includes: a first substrate 1, a second substrate 2, a first circuit layer 3, a second circuit layer 6, and a via hole 4. Among them, the first substrate 1 and the second substrate 2 are bonded through an AD film layer 5. At the same time, the first substrate 1 has a routing groove position, and the first substrate 1 with the routing groove position is bonded to the second substrate 2 to form a stepped substrate with a step height difference.

[0136] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for manufacturing a high-precision step circuit board, characterized in that: include: providing a first substrate and a second substrate; Performing a first pretreatment on the first substrate to obtain a first substrate to be pressed, wherein the first substrate has a groove position; Performing a second pretreatment on the second substrate to obtain a second substrate to be pressed; Performing a lamination process on the first substrate to be laminarized and the second substrate to be laminarized to obtain a laminar substrate with a step, wherein the gong groove is in contact with the second substrate; Performing a third pretreatment on the laminated substrate with steps to obtain a substrate after the third pretreatment; Performing a molding process on the substrate after the third pretreatment to obtain a high-precision step circuit board; The second substrate is subjected to a second pretreatment to obtain a second substrate to be pressed, comprising: Cutting the second substrate according to second preset cutting parameters to obtain a cut second substrate; Performing a drilling process on the cut second substrate to obtain a drilled second substrate; The drilled second substrate is subjected to grinding, lamination, exposure and development processes to obtain a second substrate with an anti-corrosion protection layer; Performing an etching and film stripping process on the second substrate formed with the anti-corrosion protection layer to obtain a second substrate to be laminated; The first substrate to be pressed and the second substrate to be pressed are pressed together to obtain a pressed substrate with steps, including: Performing a browning treatment on the second substrate to be pressed to obtain a browned second substrate; Performing a stacking and riveting process on the browned second substrate and the grooves of the first substrate to obtain a stacked and riveted substrate; Performing a pressing process on the substrate after the stacked plates are riveted to obtain a pressed substrate with steps; The etching and film stripping processing time of the first substrate and the second substrate is determined according to the ambient temperature of the substrate during etching, the copper thickness of the circuit on the substrate, the line width of the actual circuit, the etching rate and the side etching effect, specifically: in, t is the etching and film stripping processing time, m T is the ambient temperature influence coefficient, T is the etching environment temperature, K is the actual line width, K = K 1–2× K s , K 1 is the line width of the designed line, K s is the amount of side erosion, t 1 is the theoretical etching time, L is the copper thickness of the circuit on the substrate, V is the etching rate.

2. The method for manufacturing a high-precision stepped circuit board according to claim 1, characterized in that: Performing a first pretreatment on the first substrate to obtain a first substrate to be pressed, comprising: Cutting the first substrate according to first preset cutting parameters to obtain a cut first substrate; Performing a drilling process on the cut first substrate to obtain a drilled first substrate; The first substrate after drilling is subjected to grinding, lamination, exposure and development processes to obtain a first substrate with an anti-corrosion protection layer; Performing an etching and film stripping process on the first substrate formed with the anti-corrosion protection layer to obtain a first substrate formed with circuits; Performing adhesive film treatment on the first substrate on which the circuit is formed to obtain a first substrate with an adhesive film; The first substrate with the adhesive film is subjected to a groove opening process to obtain a first substrate to be pressed.

3. The method for manufacturing a high-precision stepped circuit board according to claim 1, characterized in that: Performing a third pretreatment on the laminated substrate with steps to obtain a substrate after the third pretreatment, comprising: Performing drilling processing on the laminated substrate with steps to obtain a drilled substrate; Performing copper deposition on the drilled substrate to obtain a copper-deposited substrate; Performing electroplating treatment on the copper-plated substrate to obtain an electroplated substrate; The substrate after the plate electroplating is subjected to a copper coating etching process to obtain a substrate after the third pretreatment.

4. The method for manufacturing a high-precision stepped circuit board according to claim 3, characterized in that: The substrate after the plate is subjected to copper coating etching treatment to obtain a substrate after the third pretreatment, comprising: The substrate after electroplating is subjected to grinding, lamination, exposure and development processes to obtain a substrate with an anti-corrosion protection layer; Performing micro-etching treatment on the substrate formed with the anti-corrosion protection layer to obtain a substrate formed with circuits; Performing a film stripping process on the substrate on which the circuit is formed to obtain a film stripped substrate; The substrate after film stripping is subjected to electroplating and etching treatment to obtain a substrate after the third pretreatment.

5. The method for manufacturing a high-precision stepped circuit board according to claim 4, characterized in that: The substrate after the film stripping is subjected to electroplating and etching treatment to obtain a substrate after the third pretreatment, comprising: The substrate after the film stripping is subjected to grinding, lamination, exposure and development treatments to obtain a substrate with an anti-corrosion protective layer; Performing pattern electroplating on the substrate formed with the anti-corrosion protection layer to obtain a pattern electroplated substrate; The substrate after pattern electroplating is etched to obtain a substrate after a third pretreatment.

6. The method for manufacturing a high-precision stepped circuit board according to claim 1, characterized in that: The substrate after the third pretreatment is subjected to a molding process to obtain a high-precision step circuit board, comprising: performing optical inspection on the substrate after the third pretreatment to obtain a substrate after optical inspection; Performing solder mask text processing on the substrate after the optical inspection to obtain a substrate after the solder mask text processing; Performing surface gold immersion treatment on the substrate after the solder mask text processing to obtain a substrate after the surface gold immersion treatment; The substrate with the surface immersion gold is cut and formed to obtain a high-precision step circuit board.

7. The method for manufacturing a high-precision stepped circuit board according to claim 1, characterized in that: Also includes: The high-precision step circuit board is tested and inspected according to preset test conditions to obtain a qualified high-precision step circuit board; the preset test conditions include at least one of the following conditions: Open circuit and short circuit test conditions, test voltage is 20~500V, test current is 5~200mA, continuity test range is 2~10000ohm, insulation test range is 5~500Mohm, equivalent test range is 0.1pF~10mF, ambient temperature is 22℃~26℃.

8. A high-precision step circuit board, characterized in that: The high-precision step circuit board is prepared by the method described in any one of claims 1 to 7.

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