A method of producing a circuit board

Abstract

The application is a circuit board production method, comprising the following steps: S1, performing rough cleaning on the wafer surface of the etched circuit board; S2, placing the wafer after rough cleaning into a vacuum cavity, performing vacuumization on the vacuum cavity, and the vacuum degree in the vacuum cavity ranges from 5 Pa to 2 Pa; S3, introducing inert gas into the vacuum cavity at a speed ranging from 10 to 5000 sccm, performing electrification on the graphite electrode at a voltage ranging from 200 to 5000 V; and completing one cleaning; in the application, the graphite electrode is used as a target source to ionize the inert gas and active gas, the problem that the metal electrode as a target source causes damage to the surface cleaning of the circuit board is solved, and the surface Darcy value of the circuit board is effectively improved; the inert gas and active gas are used to clean the surface of the circuit board at the same time, the oxidation rate of the surface film of the circuit board after cleaning can reach 99.9%, the wafer surface is cleaned twice, the surface cleanliness of the wafer is ensured, and the use effect of the circuit board is improved.

Description

Technical Field

[0001] This invention relates to the field of circuit board technology, and in particular to a method for manufacturing circuit boards. Background Technology

[0002] A circuit board (PCB) is a silicon wafer used to manufacture silicon semiconductor circuits. Its raw material is silicon. High-purity polycrystalline silicon is dissolved, doped with silicon crystal seeds, and then slowly pulled out to form cylindrical single-crystal silicon. After grinding, polishing, and slicing, the silicon ingot forms a silicon circuit board wafer, or PCB. Currently, domestic PCB production lines mainly produce 8-inch and 12-inch wafers. The main processing methods for PCBs are wafer fabrication and batch processing, which involves processing one or more PCBs simultaneously. As semiconductor feature sizes become smaller and processing and measurement equipment becomes more advanced, new data characteristics have emerged in PCB processing. Simultaneously, the reduction in feature size increases the impact of airborne particles on the quality and reliability of the PCB after processing, and with improved cleanliness, new data characteristics regarding particle count have also emerged.

[0003] In the prior art, metal electrodes are often used when cleaning the surface of circuit boards. The metal electrodes are oxidized in the atmosphere of active gas and ionized under high voltage, which impacts the surface of the circuit board, resulting in poor surface cleanliness. Moreover, since the ion beam mostly impacts the front, it cannot effectively clean the sides of the circuit board. Summary of the Invention

[0004] In view of this, the present invention aims to propose a circuit board manufacturing method to solve the problem that in the existing surface cleaning of circuit boards, metal electrodes are often used. These metal electrodes are oxidized in an atmosphere of active gas and ionized under high voltage, which impacts the surface of the circuit board and results in poor surface cleanliness.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A method for manufacturing a circuit board includes the following steps:

[0007] S1. Roughly clean the etched circuit board using the wafer surface;

[0008] S2. Place the roughly cleaned wafer into the vacuum chamber and evacuate the vacuum chamber. The vacuum level in the vacuum chamber is between 5 Pa and 2 Pa.

[0009] S3, inert gas is introduced into the vacuum chamber, the inert gas is introduced at a speed ranging from 10-5000sccm, constant temperature cooling water is introduced into the graphite electrode, the cage with the substrate is rotated at high speed, the cylindrical target material is rotated, the magnetic field is faced to the substrate through the insulating electrode, the power negative high voltage is connected to the graphite electrode, the graphite electrode is powered, the power voltage ranges from 200-5000v;

[0010] S4, active gas is introduced into the vacuum chamber, the active gas is introduced at a speed ranging from 10-5000sccm, the cleaning time ranges from 0.5-2h, and one cleaning is completed;

[0011] S5, the wafer after one cleaning is placed into the vacuum chamber, the vacuum chamber is provided with a partition plate, the partition plate divides the vacuum chamber into an inert gas chamber and an active gas chamber, the vacuum chamber is vacuumized, and the vacuum degree in the vacuum chamber ranges from 5pa-2pa;

[0012] S6, inert gas is introduced into the inert gas chamber, the inert gas is introduced at a speed ranging from 10-5000sccm, active gas is introduced into the active gas chamber, and the active gas is introduced at a speed ranging from 10-5000sccm;

[0013] S7, the graphite electrodes in the inert gas chamber and the active gas chamber are powered respectively, and the power voltage ranges from 200-5000v;

[0014] S8, the wafer is rotated from the inert gas chamber to the active gas chamber, the rotation speed ranges from 0.2-0.6r / min, the cleaning time ranges from 1.5-2h, and the second cleaning is completed;

[0015] S9, the wafer after cleaning is patterned and etched.

[0016] Preferably, in the step S1, the wafer surface is coarsely cleaned by placing the circuit board into NMP solution for degumming to remove gum objects on the surface of the circuit board.

[0017] Preferably, in the step S2, a rotating frame is arranged in the vacuum chamber, and the rotating frame drives the circuit board to rotate from the inert gas chamber to the active gas chamber.

[0018] Preferably, in the steps S3 and S6, the inert gas is any one of helium, neon, argon, krypton, xenon, and radon gas.

[0019] Preferably, in the steps S4 and S6, the active gas is oxygen.

[0020] Preferably, the etching step in step S9 is using a resin system with a specific form; using a mold matching the shape of the circuit board and the wiring pattern on the circuit board; placing the resin system in the mold; directly pouring or molding the shape of the circuit board and the wiring pattern on the circuit board through the mold; and filling the conductive material on the wiring pattern to form the conductive pattern of the circuit board.

[0021] Compared with the prior art, the circuit board production method has the following advantages:

[0022] 1. The graphite electrode is used as the target source to ionize the inert gas and the active gas, which solves the problem of damage to the surface of the circuit board caused by the metal electrode as the target source, and effectively improves the surface DFT value of the circuit board.

[0023] 2. The inert gas and the active gas are used to clean the surface of the circuit board at the same time, so that the oxidation rate of the surface film of the cleaned circuit board can reach 99.9%.

[0024] 3. The surface of the wafer is cleaned twice to ensure the surface cleanliness of the wafer and improve the use effect of the circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments of the present application will be briefly introduced below. The drawings are only used to show some embodiments of the present application, and the present application is not limited to the drawings.

[0026] Figure 1 The circuit board cleaning flowchart in the fourth embodiment of the present application;

[0027] Figure 2 The circuit board cleaning device diagram in the fourth embodiment of the present application;

[0028] Figure 3 The material distribution state diagram in the circuit board cleaning process of the present application;

[0029] Figure 4 The simple diagram of the circuit board cleaning system of the present application;

[0030] Figure 5 The simple diagram of the ion distribution area in the cleaning system of the present application.

[0031] Reference signs:

[0032] 1. Main body; 2. Cavity; 3. Vacuum pump group; 4. Isolation plate; 5. Flexible joint; 6. Rotary frame; 7. Graphite electrode; 8. Inert gas tank; 9. Solenoid valve; 10. Vacuum degree detector; 11. High-voltage power supply; 12. Active gas tank. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the drawings.

[0034] Embodiment one:

[0035] A circuit board production method, comprising the following steps:

[0036] S1, the wafer surface of the etched circuit board is placed in NMP solution for degreasing;

[0037] S2, the wafer after rough cleaning is placed in a vacuum chamber, the vacuum chamber is vacuumized, and the vacuum degree in the vacuum chamber is 5pa;

[0038] S3, argon is introduced into the vacuum chamber at a speed of 10sccm, the graphite electrode is powered on, and the power-on voltage is 200v;

[0039] S4, oxygen is introduced into the vacuum chamber at a speed of 10sccm, and the cleaning time is 0.5h, completing a cleaning;

[0040] S5, the wafer after the first cleaning is placed in the vacuum chamber, the vacuum chamber is provided with a partition plate, the partition plate divides the vacuum chamber into an inert gas chamber and an active gas chamber, the vacuum chamber is vacuumized, and the vacuum degree in the vacuum chamber is 5pa;

[0041] S6, argon is introduced into the inert gas chamber at a speed of 10sccm, and oxygen is introduced into the active gas chamber at a speed of 10sccm;

[0042] S7, the graphite electrodes in the inert gas chamber and the active gas chamber are powered on respectively, and the power-on voltage is 200v;

[0043] S8, the wafer is rotated from the inert gas chamber to the active gas chamber at a rotation speed of 0.2r / min, and the cleaning time is 1.5h, completing a second cleaning;

[0044] S9, the wafer after cleaning is etched, the etching step is to use a special resin system, adopt a mold matched with the shape of the circuit board and the wiring pattern on the circuit board, place the above resin system in the mold, directly cast or mold the shape of the circuit board and the wiring pattern on the circuit board through the mold, and fill the conductive material on the wiring pattern to form the conductive pattern of the circuit board.

[0045] Embodiment two:

[0046] On the basis of embodiment one, the circuit board production method of embodiment one is further optimized:

[0047] A circuit board production method, comprising the following steps:

[0048] S1, the wafer surface of the etched circuit board is placed in NMP solution for degreasing;

[0049] S2, the wafer after rough cleaning is placed in a vacuum chamber, the vacuum chamber is vacuumized, and the vacuum degree in the vacuum chamber is 4pa;

[0050] S3, argon is introduced into the vacuum chamber at a speed of 500sccm, the graphite electrode is powered, and the power voltage is 500v;

[0051] S4, oxygen is introduced into the vacuum chamber at a speed of 500sccm, and the cleaning time is 1h, completing a cleaning;

[0052] S5, the wafer after the first cleaning is placed in the vacuum chamber, the vacuum chamber is provided with a partition plate, the partition plate divides the vacuum chamber into an inert gas chamber and an active gas chamber, the vacuum chamber is vacuumized, and the vacuum degree in the vacuum chamber is 4pa;

[0053] S6, argon is introduced into the inert gas chamber at a speed of 500sccm, and oxygen is introduced into the active gas chamber at a speed of 500sccm;

[0054] S7, the graphite electrodes in the inert gas chamber and the active gas chamber are powered respectively, and the power voltage is 500v;

[0055] S8, the wafer is rotated from the inert gas chamber to the active gas chamber at a rotating speed of 0.5r / min, and the cleaning time is 1.5h, completing secondary cleaning;

[0056] S9, the cleaned wafer is etched, the etching step is to use a special resin system, adopt a mold matched with the shape of the circuit board and the wiring pattern on the circuit board, place the resin system in the mold, directly cast or mold the shape of the circuit board and the wiring pattern on the circuit board through the mold, and fill the conductive material on the wiring pattern to form the conductive pattern of the circuit board.

[0057] Example three:

[0058] On the basis of example one, the circuit board production method of example one is further optimized:

[0059] A circuit board production method, comprising the following steps:

[0060] S1, the wafer surface of the etched circuit board is placed in NMP solution for degreasing;

[0061] S2, the wafer after rough cleaning is placed into a vacuum chamber, the vacuum chamber is vacuumized, and the vacuum degree in the vacuum chamber is 3 Pa;

[0062] S3, argon is introduced into the vacuum chamber at a speed of 2500 sccm, the graphite electrode is powered, and the power voltage is 2500 V;

[0063] S4, oxygen is introduced into the vacuum chamber at a speed of 2500 sccm, and the cleaning time is 2 h, to complete a cleaning;

[0064] S5, the wafer after the first cleaning is placed into the vacuum chamber, the vacuum chamber is provided with a partition plate, the partition plate divides the vacuum chamber into an inert gas chamber and an active gas chamber, the vacuum chamber is vacuumized, and the vacuum degree in the vacuum chamber is 3 Pa;

[0065] S6, argon is introduced into the inert gas chamber at a speed of 2500 sccm, and oxygen is introduced into the active gas chamber at a speed of 2500 sccm;

[0066] S7, the graphite electrodes in the inert gas chamber and the active gas chamber are powered respectively, and the power voltage is 3000 V;

[0067] S8, the wafer is rotated from the inert gas chamber to the active gas chamber at a rotating speed of 0.4 r / min, and the cleaning time is 2 h, to complete a second cleaning;

[0068] S9, the cleaned wafer is etched, the etching step is to use a special resin system, adopt a mold matched with the shape of the circuit board and the wiring pattern on the circuit board, place the resin system in the mold, directly cast or mold the shape of the circuit board and the wiring pattern on the circuit board through the mold, and fill the conductive material on the wiring pattern to form the conductive pattern of the circuit board.

[0069] Example Four

[0070] On the basis of example one, the circuit board production method of example one is further optimized:

[0071] A circuit board production method, comprising the following steps:

[0072] S1, the etched circuit board wafer surface is placed into NMP solution for degumming;

[0073] S2, the wafer after rough cleaning is placed into a vacuum chamber, the vacuum chamber is vacuumized, and the vacuum degree in the vacuum chamber is 2 Pa;

[0074] S3, argon is introduced into the vacuum chamber at a speed of 5000 sccm, the graphite electrode is powered, and the power voltage is 5000 V;

[0075] S4, oxygen is introduced into the vacuum cavity, the speed of introducing oxygen is 5000sccm, the cleaning time is 2h, and one cleaning is completed;

[0076] S5, the wafer after one cleaning is placed into the vacuum cavity, the vacuum cavity is provided with a partition plate, the partition plate divides the vacuum cavity into an inert gas chamber and an active gas chamber, the vacuum cavity is vacuumized, and the vacuum degree in the vacuum cavity is 2pa;

[0077] S6, argon is introduced into the inert gas chamber at a speed of 5000sccm, and oxygen is introduced into the active gas chamber at a speed of 5000sccm;

[0078] S7, the graphite electrodes in the inert gas chamber and the active gas chamber are respectively powered, and the power voltage is 5000v;

[0079] S8, the wafer is rotated from the inert gas chamber to the active gas chamber, the rotation speed is 0.2r / min, the cleaning time is 2h, and the secondary cleaning is completed;

[0080] S9, the wafer after cleaning is etched, the etching step is to use a special resin system; adopt a mold matched with the shape of the circuit board and the wiring pattern on the circuit board; the above resin system is placed in the above mold; the shape of the circuit board and the wiring pattern on the circuit board are directly cast or molded by the mold; the wiring pattern is filled with conductive material to form a conductive pattern of the circuit board.

[0081] The isolation plate 4 divides the vacuum cavity into an inert gas chamber and an active gas chamber, the flexible joint 5 seals the rotary frame and the isolation plate 4, the parts to be cleaned are placed on the rotary frame 6, the vacuum pump set 3 first performs vacuumization on the cavity 2 of the main body 1, so that the cavity 2 is a vacuum cavity 2; the vacuum degree detector 10 detects the vacuum degree inside the cavity 2, and different parts can be cleaned at different vacuum degrees; then the graphite electrode 7 is electrically connected with the high-voltage power supply 11, so that an alternating electric field is formed in the cavity 2; then the inert gas tank 8 and the active gas tank 12 are used to introduce inert gas and active gas into the cavity 2, the electromagnetic valve 9 controls the ventilation speed of the inert gas and the active gas, and the isolation plate 4 separates the cavity 2, so that the two sides of the isolation plate 4 are respectively in an inert gas atmosphere and an active gas atmosphere; in the inert gas atmosphere, the inert gas can be helium, neon, argon, etc., which can be selected according to production needs; under the action of the electric field, the graphite electrode emits a large number of electrons flying to the grounded anode, and collides with the argon and oxygen in the vacuum to produce plasma, which bombards and cleans the residues on the surface of the circuit board; for the strong pollutants remaining on the surface of the circuit board, the surface of the circuit board is cleaned by plasma bombardment, which is a green and non-damaging cleaning method, and because the volume of the plasma is smaller than that of the water molecule, it can penetrate into the fine pores and the inside of the circuit board to complete the cleaning, thereby improving the cleaning effect; in the active gas atmosphere, positive ions accelerate to the graphite electrode to produce sputtering reaction, and the graphite electrode and the active gas produce oxidation reaction; the sputtered substances react with oxygen and oxygen ions in the vacuum to generate oxides, part of the oxygen is ionized by high pressure to generate ozone, the generated ozone and the residues on the surface of the circuit board produce strong oxidation reaction to generate oxidation products on the surface of the circuit board, and the oxidation products are separated from the surface of the circuit board by the bombardment of the plasma, thereby achieving the purpose of auxiliary cleaning, and negative ions accelerate to the circuit board and C and CC that have not completed oxidation to produce reaction, and the generated CO2 and CO bombard and clean the surface of the circuit board; all the above substances finally exist in the form of gas or electrons, so there is no or little residue on the circuit board, thereby achieving the purpose of cleaning;

[0082] The resin system is physically mixed, and after being mixed uniformly, the resin system is heated to semi-curing, and after semi-curing to a certain extent, the resin system is kept in a molten state, and ordered reinforcing materials are added, the reinforcing materials are orderly hung in the independent mold, a releasing agent is applied to the side of the independent mold in contact with the resin system, the resin system in a molten state is poured into the independent mold matching the shape of the cleaned wafer and the wiring pattern on the circuit board, the mixture of the resin system in a molten state and the reinforcing materials is completely cured in the independent mold by heat curing, the heating temperature is 120-150℃, the resin system completely cured is separated from the independent mold, at this time, the shape of the resin system matches the required shape of the circuit board, and the surface of the resin system forms a wiring pattern, the releasing agent on the surface of the wafer is removed, and a conductive material is filled on the wiring pattern directly formed by the independent mold to form a circuit board wiring pattern.

[0083] The surface Darcy value and the film layer oxidation rate of the cleaned circuit board in Examples 1-4 are shown in Table 1:

[0084] Table 1

[0085] Dyne value Oxidation rate of film layer (%) Example one 58 97.5 Example two 60 98.9 Example three 60 or more 99.9 Example four 60 or more 99.9

[0086] The surface cleanliness Darcy value of the circuit board treated by the cleaning method of the present embodiment can reach 60, and the film layer oxidation rate can reach 99.9%, effectively improving the cleaning effect of the circuit board surface.

[0087] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art, without departing from the spirit and scope of the present application, can make various changes and modifications, therefore, the protection scope of the present application should be limited by the scope defined in the claims.

Claims

1. A method of producing a circuit board, characterized by, It comprises the following steps: S1, the surface of the circuit board is roughly cleaned, and the circuit board is placed in an NMP solution for degumming to remove gum objects on the surface of the circuit board; S2, the circuit board after rough cleaning is placed in a vacuum chamber, the vacuum chamber is vacuumized, and the vacuum degree in the vacuum chamber ranges from 5pa to 2pa; S3, inert gas is introduced into the vacuum chamber, the inert gas introduction speed ranges from 10 to 5000sccm, constant temperature cooling water is introduced into the graphite electrode, the cage rack with the circuit board is rotated at high speed, the cylindrical target material is rotated, the magnetic field faces the circuit board, the power negative high voltage is connected to the graphite electrode, the graphite electrode is powered, and the power voltage ranges from 200 to 5000V; S4, active gas is introduced into the vacuum chamber, the active gas introduction speed ranges from 10 to 5000sccm, and the cleaning time is 0.5-2h, completing a cleaning; S5, the circuit board after the first cleaning is placed in the vacuum chamber, the vacuum chamber is provided with a partition plate, the partition plate divides the vacuum chamber into an inert gas chamber and an active gas chamber, the vacuum chamber is vacuumized, and the vacuum degree in the vacuum chamber ranges from 5pa to 2pa, wherein a rotating frame is arranged in the vacuum chamber, the rotating frame drives the circuit board to rotate from the inert gas chamber to the active gas chamber; S6, inert gas is introduced into the inert gas chamber, the inert gas introduction speed ranges from 10 to 5000sccm, and active gas is introduced into the active gas chamber, the active gas introduction speed ranges from 10 to 5000sccm; S7, the graphite electrodes in the inert gas chamber and the active gas chamber are powered respectively, and the power voltage ranges from 200 to 5000V; S8, the circuit board is rotated from the inert gas chamber to the active gas chamber, the rotation speed ranges from 0.2 to 0.6r / min, the cleaning time is 1.5-2h, and the second cleaning is completed; S9, the surface of the cleaned circuit board is patterned and etched, the etching step is to use a resin system, a mold matched with the shape of the circuit board and the wiring pattern on the circuit board, the resin system is placed in the mold, the shape of the circuit board and the wiring pattern on the circuit board are directly cast or molded by the mold, and conductive material is filled on the wiring pattern to form a conductive pattern of the circuit board; In step S3 and step S6, the inert gas is any one of helium, neon, argon, krypton, xenon and radon gas; In step S4 and step S6, the active gas is oxygen.

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