Automobile intelligent braking circuit board and production process thereof

Abstract

The application discloses a kind of circuit board for automobile intelligent braking and production process thereof, including circuit board body, the circuit board body includes circuit substrate, the surface of the circuit substrate is bonded with heat conduction even heat plate, and even heat plate is provided with oxidation-resistant film, the surface of the oxidation-resistant film is coated with corrosion-resistant layer, the place of concentrated heat on circuit board is evenly conducted to other positions of circuit board by the heat conduction of even heat plate, and when the temperature of circuit board surface is higher, the heat of circuit board surface can be conducted to isolation groove by heat-conducting silicone grease, and when the temperature of circuit board surface is lower, the temperature of circuit board surface can also be made more balanced, so that the temperature range that the circuit board can adapt is larger, and by forming oxidation-resistant layer and corrosion-resistant layer on the surface of circuit board body, the service life of the circuit board in harsh environment can be improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of automobile circuit boards, in particular to an automobile intelligent braking circuit board and a production process thereof. BACKGROUND

[0002] The automobile braking circuit board is a key component for various automobile electronic systems and is mainly used for intelligent control of automobiles. With the increasing popularity of new energy vehicles and hybrid electric vehicles, the automobile intelligent braking circuit board can not only improve vehicle performance and operation safety but also bring better driving experience. Therefore, more electronic components and circuits need to be integrated and installed on the automobile braking circuit board.

[0003] A kind of automobile high bending resistance circuit board and its preparation method are disclosed in Chinese patent (publication number: CN113038696B). The automobile high bending resistance circuit board designed by the patent is made of a rigid bending-resistant resin with good elasticity, and is provided with a buffer groove and an elastic connecting rib, thereby significantly improving the flexibility of the circuit board, changing the elasticity, flexibility and bending resistance of the circuit board. When designing the automobile circuit board, the use environment is given priority to. In the environment with high latitude, the temperature is often around minus 20 DEG C, and in the relatively harsh environment, the braking circuit board often ages due to high temperature, corrosion, etc. The service life of the automobile braking circuit board is significantly reduced. SUMMARY

[0004] The purpose of the present application is to provide an automobile intelligent braking circuit board and a production process thereof. The concentrated heating place on the circuit board is uniformly conducted to other positions of the circuit board by the heat conduction of the heat plate. When the temperature of the surface of the circuit board is high, the heat on the surface of the circuit board can be conducted to the isolation groove by the heat-conducting silicone grease. When the surface temperature of the circuit board is low, the temperature of the surface of the circuit board can also be balanced. Therefore, the temperature range that the circuit board can adapt to is large. By forming an oxidation-resistant layer and a corrosion-resistant layer on the surface of the circuit board body, the service life of the circuit board in harsh environments can be improved.

[0005] The purpose of the present application can be achieved by the following technical solutions:

[0006] The application discloses an automobile intelligent braking circuit board and a production process thereof.

[0007] The application further discloses a production process of the automobile intelligent braking circuit board.

[0008] Step one: the circuit substrate is subjected to a PCB pre-process to obtain a circuit substrate with through holes, then a layer of heat plate is adhered to the surface of the circuit substrate according to the surface shape of the circuit substrate to obtain assembly one.

[0009] Step two: the surface of the assembly one is coated with an antioxidant solution and is allowed to stand for 10-20 min, and the process is repeated for 2-3 times, so that an antioxidant film is formed on the surface of the heat plate, thereby obtaining assembly two.

[0010] Step three: the assembly three is placed in a drying oven for baking, then the surface of the baked assembly two is coated with an anticorrosion solution to form an anticorrosion layer, and is subjected to secondary drying, thereby obtaining assembly three.

[0011] Step four: the assembly three is subjected to copper deposition, so that a copper deposition hole is formed in the through hole for electrical connection, and the interlayer of the circuit substrate is communicated, thereby obtaining a circuit board body.

[0012] Step four: through holes for connection are drilled on the surface of the circuit board body, then heat-conducting silicone grease is applied to the inner surface of the heat sink, and the heat sink is connected with the circuit board body through the connecting column.

[0013] Step five: electronic components are welded by welding.

[0014] As a further scheme of the application, the antioxidant solution comprises the following raw materials in parts by weight: 10-30 parts of ethanol, 5-15 parts of acetic acid, 1-5 parts of benzoic acid, 0.1-1 part of ethylenediaminetetraacetic acid and 50-70 parts of water; and the preparation method of the antioxidant solution comprises the following steps: water is introduced into a reaction kettle, then ethanol, acetic acid and benzoic acid are introduced into the reaction kettle to be mixed with the water, and after stirring, ethylenediaminetetraacetic acid is added and is subjected to ultrasonic oscillation at 40 kHz for 1 h, so that the antioxidant solution is obtained.

[0015] As a further scheme of the present application: the anti-corrosion liquid is mixed by polyimide resin and ethanol according to 1g:50ml, since the polyimide resin is not easy to react with the formed antioxidant film, the anti-corrosion property is achieved while avoiding the damage to the antioxidant film.

[0016] As a further scheme of the present application:

[0017] The baking time in the third step is 1-2h, and the baking temperature is 40-60℃, and the coating thickness of the heat-conducting silicone grease in the fourth step is 0.5-1mm.

[0018] The beneficial effects of the present application:

[0019] (1) In the present application, by arranging the heat spreading plate on the surface of the circuit board, the heat concentrated on the circuit board can be uniformly conducted to other positions of the circuit board through the heat spreading plate, and when the temperature of the surface of the circuit board is high, the heat of the surface of the circuit board can be conducted to the isolation groove through the heat-conducting silicone grease, and when the temperature of the surface of the circuit board is low, the temperature of the surface of the circuit board can also be made more uniform, so that the temperature range that the circuit board can adapt to is larger, and by forming the antioxidant layer and the corrosion-resistant layer on the surface of the circuit board body, the service life of the circuit board in harsh environments can be improved.

[0020] (2) In the present application, ethanol, acetic acid, benzoic acid and ethylenediaminetetraacetic acid are used as the main raw materials of the antioxidant liquid to be coated on the heat spreading plate made of copper, which can remove the oxides on the surface of the heat spreading plate, and the ethylenediaminetetraacetic acid forms copper ethylenediaminetetraacetic acid complex on the surface of the heat spreading plate to form a protective film on the surface of the heat spreading plate, thereby improving the antioxidant ability, and the mixture of polyimide resin and ethanol is coated on the circuit board body to prevent the threat of various chemical corrosion in harsh environments by using the chemical corrosion resistance of polyimide resin, thereby further prolonging the service life. BRIEF DESCRIPTION OF DRAWINGS

[0021] The present application will be further described below with reference to the accompanying drawings.

[0022] Fig. 1 is a partial sectional view of the circuit board in the present application;

[0023] Fig. 2 is a top view of the external structure of the circuit board in the present application.

[0024] In the drawings: 1, circuit board body; 11, circuit substrate; 12, heat spreading plate; 13, antioxidant film; 14, corrosion-resistant layer; 15, copper plating hole; 2, heat spreading plate; 3, connecting column; 4, connecting hole; 5, heat-conducting silicone grease. DETAILED DESCRIPTION

[0025] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present application.

[0026] Please refer to Figs. 1-2 As shown in the drawings, an automobile intelligent braking circuit board comprises a circuit board body 1, the circuit board body 1 comprises a circuit substrate 11, and a heat equalizing plate 12 for heat conduction is bonded on the surface of the circuit substrate 11. The material of the heat equalizing plate 12 is copper, and the glue between the circuit substrate 11 and the heat equalizing plate 12 is non-conductive glue. The heat equalizing plate 12 can evenly distribute the heat on the surface of the circuit board on the circuit board body 1. When the temperature on the circuit board body 1 is low, the temperature on the circuit board can be improved as a whole. When the temperature on the circuit board body 1 is high, the heat can be evenly distributed on the entire circuit board body 1, so as to avoid that the local temperature of the circuit board body 1 is too high. An oxidation-resistant film 13 is arranged on the heat equalizing plate 12, the surface of the oxidation-resistant film 13 is coated with a corrosion-resistant layer 14, and heat dissipation plates 2 are arranged on both sides of the circuit board body 1. The cross section of the heat dissipation plate 2 is in the shape of C. A plurality of connecting holes 4 are arranged on the heat dissipation plate 2, connecting columns 3 for connection are arranged between the circuit board body 1 and the connecting holes 4, and the inner surface of the heat dissipation plate 2 on one side of the circuit board body 1 is filled with heat-conducting silicone grease 5. A plurality of isolation grooves are arranged on the opposite side of the heat dissipation plate 2, so as to play a certain heat dissipation role when the heat on the circuit board is too high. The cross section of the heat dissipation plate 2 is in the shape of C. A plurality of copper sinking holes 15 are arranged on the circuit substrate 11 according to the circuit layout.

[0027] Embodiment 1

[0028] The embodiment provides a production process of an automobile intelligent braking circuit board, which specifically comprises the following steps.

[0029] Step 1: The circuit substrate is subjected to PCB pre-process to obtain a circuit substrate 11 with a through hole, and then a heat equalizing plate 12 is bonded on the surface of the circuit substrate 11 to obtain assembly one.

[0030] Step 2: The surface of assembly one is coated with an oxidation-resistant liquid, and is subjected to static placement for 20 min, and the process is repeated twice, so as to form an oxidation-resistant film 13 on the surface of the copper heat equalizing plate 12, thereby obtaining assembly two.

[0031] Step three: place the assembly three in the drying oven at a temperature of 40℃ for 2h, then coat the surface of the baked assembly two with the corrosion-resistant liquid mixed by 1g of polyimide resin and 50mL of ethanol, so as to form a corrosion-resistant layer 14, and dry again, so as to obtain the assembly three;

[0032] Step four: carry out copper plating on the assembly three, so as to form a copper-plated hole 15 in the through hole for electrical connection, and communicate the interlayer of the circuit substrate 11, so as to obtain the circuit board body 1;

[0033] Step four: drill a through hole for connection on the surface of the circuit board body 1, then smear a thickness of 0.5mL of heat-conducting silicone grease 5 on the inner surface of the heat dissipation plate 2, and connect the heat dissipation plate 2 with the circuit board body 1 through the connecting column 3;

[0034] Step five: weld the electronic components by welding.

[0035] The preparation method of the antioxidant liquid comprises the following steps: 50 parts of water are introduced into a reaction kettle, then 10 parts of ethanol, 5 parts of acetic acid and 1 part of benzoic acid are introduced into the reaction kettle to react with the water, and after stirring, 0.1 part of ethylenediaminetetraacetic acid is added and ultrasonic oscillation is carried out at 40kHz for 1h, so as to obtain the antioxidant liquid.

[0036] Example 2

[0037] The embodiment provides a production process of a circuit board for automobile intelligent braking: specifically comprising the following steps:

[0038] Step one: carry out PCB pre-process treatment on the circuit substrate to obtain a circuit substrate 11 with a through hole, then cover a heat plate 12 on the surface of the circuit substrate 11 in an adhesive manner according to the surface shape of the circuit substrate 11, so as to obtain an assembly one;

[0039] Step two: coat the surface of the assembly one with an antioxidant liquid, and stand for 10min and repeat 3 times, so as to form an antioxidant film 13 on the surface of the copper heat plate 12, so as to obtain an assembly two;

[0040] Step three: place the assembly three in the drying oven at a temperature of 60℃ for 1h, then coat the surface of the baked assembly two with the corrosion-resistant liquid mixed by 1g of polyimide resin and 50mL of ethanol, so as to form a corrosion-resistant layer 14, and dry again, so as to obtain the assembly three;

[0041] Step four: carry out copper plating on the assembly three, so as to form a copper-plated hole 15 in the through hole for electrical connection, and communicate the interlayer of the circuit substrate 11, so as to obtain the circuit board body 1;

[0042] Step four: drilling a through hole for connection on the surface of the circuit board body 1, then smearing the inner surface of the heat dissipation plate 2 with a thickness of 1 mL of heat-conducting silicone grease 5, and connecting the heat dissipation plate 2 with the circuit board body 1 through the connecting column 3;

[0043] Step five: welding the electronic components by welding.

[0044] The preparation method of the antioxidant solution comprises the following steps: 70 parts of water are introduced into a reaction kettle, then 30 parts of ethanol, 15 parts of acetic acid and 5 parts of benzoic acid are introduced into the reaction kettle to react with the water, and stirring is performed, then 1 part of ethylenediaminetetraacetic acid is added, and ultrasonic oscillation is performed at 40 kHz for 1 h, so that the antioxidant solution is obtained.

[0045] Example 3

[0046] The embodiment provides a production process of a circuit board for automobile intelligent braking, which specifically comprises the following steps:

[0047] Step one: performing a PCB pre-process on a circuit substrate to obtain a circuit substrate 11 with a through hole, then covering a surface of the circuit substrate 11 with a heat plate 12 in an adhesive manner according to a surface shape of the circuit substrate 11 to obtain assembly one;

[0048] Step two: coating the surface of assembly one with an antioxidant solution, and standing for 15 min and repeating three times, so that an antioxidant film 13 is formed on the surface of the copper heat plate 12, thereby obtaining assembly two;

[0049] Step three: placing assembly three in a drying oven and baking at a temperature of 50 DEG C for 1.5 h, then coating the surface of the baked assembly two with an anticorrosive solution mixed by 1 g of polyimide resin and 50 mL of ethanol to form a corrosion-resistant layer 14, and performing re-drying, thereby obtaining assembly three;

[0050] Step four: performing copper plating on assembly three, so that a copper plating hole 15 is formed in the through hole for electrical connection, and the interlayer of the circuit substrate 11 is connected, thereby obtaining a circuit board body 1;

[0051] Step four: drilling a through hole for connection on the surface of the circuit board body 1, then smearing the inner surface of the heat dissipation plate 2 with a thickness of 0.7 mL of heat-conducting silicone grease 5, and connecting the heat dissipation plate 2 with the circuit board body 1 through the connecting column 3;

[0052] Step five: welding the electronic components by welding.

[0053] The preparation method of the antioxidant solution comprises the following steps: 65 parts of water are introduced into a reaction kettle, then 40 parts of ethanol, 10 parts of acetic acid and 3 parts of benzoic acid are introduced into the reaction kettle to react with the water, and stirring is performed, 0.5 parts of ethylenediaminetetraacetic acid is added, and ultrasonic oscillation is performed at 40 kHz for 1 h, so as to obtain the antioxidant solution.

[0054] Comparative experiment:

[0055] The circuit boards obtained in Examples 1, 2 and 3 are subjected to aging test, and the surface oxidation degrees of the circuit boards are tested. The test method is as follows: an accelerated aging test is performed on the circuit boards by using a constant temperature and humidity test box, the temperature is set to 85℃, a pure sodium chloride aqueous solution with a concentration of 5% is sprayed on each circuit board, the duration is 200 hours, and then each circuit board is washed with clean water.

[0056] The surface oxidation degree: the surface of the circuit board is scanned by using an x-ray photoelectron spectrometer (XPS), the proportion of copper element and oxygen element on the surface is measured, the surface oxidation rate is calculated, and the surface resistance value is measured by using a multimeter to evaluate the reliability.

[0057] The test results are shown in the following table:

[0058]

[0059]

[0060] As can be seen from the table, the surface oxidation rate and the surface resistance value of Examples 1-3 change little after the aging test, and therefore the circuit board prepared by the production process of the present application has good oxidation resistance and corrosion resistance.

[0061] The above describes one embodiment of the present application in detail, but the content described is only a preferred embodiment of the present application, and cannot be considered as limiting the scope of the present application. Any equivalent changes and improvements made according to the scope of the present application should still belong to the scope of the present application.

Claims

1. A circuit board for intelligent braking of an automobile, comprising a circuit board body (1), characterized in that: The circuit board body (1) comprises a circuit substrate (11), a heat spreader (12) for heat conduction is bonded to the surface of the circuit substrate (11), an anti-oxidation film (13) is provided on the heat spreader (12), and a corrosion-resistant layer (14) is coated on the surface of the anti-oxidation film (13), a heat sink (2) is provided on both sides of the circuit board body (1), a plurality of connection holes (4) are provided on the heat sink (2), a connection column (3) for connection is provided between the circuit board body (1) and the connection hole (4), and the inner surface of the heat sink (2) and located on one side of the circuit board body (1) is filled with thermal grease (5); The production process of the automobile intelligent braking circuit board specifically includes the following steps: Step 1: performing a PCB pre-processing on the circuit substrate to obtain a circuit substrate (11) with a through hole, and then covering the surface of the circuit substrate (11) with a layer of a heat spreader (12) by bonding according to the surface shape of the circuit substrate (11) to obtain component 1; Step 2: coating the surface of component 1 with an antioxidant solution, and allowing it to stand for 10-20 minutes, and repeating this process 2-3 times, thereby forming an antioxidant film (13) on the surface of the heat spreader (12), thereby obtaining component 2; Step 3: placing component 3 in a drying oven for baking, then coating the baked surface of component 2 with an anti-corrosion liquid to form a corrosion-resistant layer (14), and drying again to obtain component 3; Step 4: copper deposition is performed on the component 3, thereby forming a copper deposition hole (15) in the conductive hole for electrical connection, connecting the layers of the circuit substrate (11), thereby obtaining a circuit board body (1); Step 4: Drill through holes for connection on the surface of the circuit board body (1), then apply thermal grease (5) on the inner surface of the heat sink (2), and connect the heat sink (2) to the circuit board body (1) through the connecting column (3); Step 5: Solder the electronic components by welding; The antioxidant solution comprises the following raw materials in parts by weight: 10-30 parts of ethanol, 5-15 parts of acetic acid, 1-5 parts of benzoic acid, 0.1-1 parts of ethylenediaminetetraacetic acid and 50-70 parts of water; The preparation method of the antioxidant liquid comprises the following steps: introducing water into a reaction kettle, then introducing ethanol, acetic acid and benzoic acid into the reaction kettle to dissolve in the water, stirring, adding ethylenediaminetetraacetic acid, and ultrasonically shaking at 40 kHz for 1 hour to obtain the antioxidant liquid; The anti-corrosion liquid is prepared by mixing polyimide resin and ethanol at a ratio of 1 g:50 mL; In step 3, the baking time is 1-2 hours and the baking temperature is 40-60°C; The thickness of the thermal grease (5) applied in step 4 is 0.5-1 mm.

2. The circuit board for automobile intelligent braking according to claim 1, characterized in that: A plurality of isolation grooves are provided on opposite sides of the two heat dissipation plates (2), and the cross-section of the heat dissipation plates (2) is arranged in a C-shape.

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