Anti-corrosion structure and circuit board

Abstract

The present invention provides an anti-corrosion structure and a circuit board, which relate to the technical field of circuit board anti-corrosion, and solve the technical problems of poor anti-corrosion performance and short service life of the circuit board structure. The device includes an active metal layer and an inert electrode layer arranged on the circuit board, the active metal layer and the inert electrode layer are connected and located on the periphery of the internal circuit; the active metal layer and the inert electrode layer can form a primary battery when in contact with corrosive substances, which is used to intercept the corrosive substances from corroding the internal circuit. The anti-corrosion structure is arranged on the periphery of the internal circuit on the circuit board, and the connected active metal layer and the inert electrode layer can form a primary battery when in contact with the corrosive liquid. When the circuit board contacts the corrosive substance, the active metal layer is first consumed to react with the corrosive liquid, the inert electrode layer and the internal circuit are protected, and the corrosive liquid is intercepted from corroding the internal circuit without affecting the circuit board to realize its own function, thereby improving the service life of the circuit board.

Description

Technical Field

[0001] The invention relates to the technical field of circuit board anti-corrosion, and in particular to an anti-corrosion structure and a circuit board. Background Art

[0002] PCB circuit boards are the core control components of equipment. When the equipment is used in harsh working environments, PCB circuit boards are required to have high corrosion resistance. In actual use, it is found that, for example, a large proportion of printed circuit boards in motherboards or hard disks have corrosion problems. The main reason is that computers in overheated working environments will produce a certain concentration of sulfide gas or corrosive substances such as external atmosphere, alkali and certain acids that corrode printed circuit boards. Especially for server products, it is very easy to have the problem of corrosion of hard disk control circuit boards. This corrosion phenomenon seriously affects the use of equipment.

[0003] In the prior art, some circuit boards are coated with an anti-corrosion coating to protect the circuit boards.

[0004] The applicant has discovered that the prior art has at least the following technical problems: when the circuit board of the above structure is used in a corrosive environment, it is equivalent to physical corrosion protection, and the anti-corrosion effect is poor. Once the coating is damaged or cracked, corrosive substances will still penetrate into the circuit board and corrode its internal circuits, so its anti-corrosion effect is very limited. Summary of the invention

[0005] The object of the present invention is to provide an anti-corrosion structure and a circuit board to solve the technical problems of poor anti-corrosion performance and short service life of the circuit board structure in the prior art; the many technical effects that can be produced by the preferred technical scheme among the many technical schemes provided by the present invention are described in detail below.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The anti-corrosion structure and circuit board provided by the present invention include an active metal layer and an inert electrode layer arranged on the circuit board, wherein: the active metal layer and the inert electrode layer are connected and located at the periphery of the internal circuit; the active metal layer and the inert electrode layer can form a primary battery when in contact with corrosive substances, which is used to intercept the corrosive substances from corroding the internal circuit.

[0008] Preferably, the active metal layer and the inert electrode layer are arranged vertically and horizontally, and / or arranged side by side left and right.

[0009] Preferably, when the active metal layer and the inert electrode layer are arranged in an up-and-down manner, the active metal layer is located on the upper part of the inert electrode layer; when the active metal layer and the inert electrode layer are arranged side by side, the active metal layer is located on the side of the inert electrode layer away from the internal circuit.

[0010] Preferably, the active metal layer and the inert electrode layer are located around the internal circuit and are spaced apart from the outermost side of the internal circuit.

[0011] Preferably, of the active metal layer and the inert electrode layer, at least the active metal layer has a width d of ≥ 300 μm in the direction from the side of the circuit board to the internal circuit.

[0012] Preferably, of the active metal layer and the inert electrode layer, at least the active metal layer is intermittently disposed around the periphery of the internal circuit.

[0013] Preferably, the distance between adjacent active metal layers is smaller than the distance between the active metal layer and the internal circuit.

[0014] Preferably, the anti-corrosion structure further includes a waterproof adhesive layer, and the waterproof adhesive layer is at least located on the upper layer and / or the lower layer of the internal circuit.

[0015] Preferably, the waterproof adhesive layer extends to the periphery of the active metal layer.

[0016] Preferably, an insulating layer is also provided on the upper layer of the waterproof adhesive layer.

[0017] The present invention also provides a circuit board, comprising an internal circuit located on a substrate and the above-mentioned anti-corrosion structure.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The anti-corrosion structure provided by the present invention is arranged on the periphery of the internal circuit on the circuit board. The connected active metal layer and the inert electrode layer can form a primary battery when in contact with the corrosive liquid. When the circuit board comes into contact with the corrosive substance, the active metal layer is first consumed to react with the corrosive liquid, thereby protecting the inert electrode layer and the internal circuit, intercepting the corrosive liquid from eroding the internal circuit, and not affecting the circuit board to realize its own function, thereby improving the service life of the circuit board.

[0020] 2. The circuit board provided by the present invention has the above-mentioned anti-corrosion structure, so it also has the advantages of good anti-corrosion performance and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is a side view of the anti-corrosion structure of the present invention on a circuit board;

[0023] Figure 2 It is a top view of the anti-corrosion structure of the present invention on a circuit board.

[0024] In the figure, 1 is the active metal layer; 2 is the inert electrode layer; 3 is the substrate; 4 is the waterproof adhesive layer; 5 is the insulating layer; 6 is the internal circuit. DETAILED DESCRIPTION

[0025] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "center", "length", "width", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "side" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0027] Example 1

[0028] The present invention provides an anti-corrosion structure, comprising an active metal layer 1 and an inert electrode layer 2 arranged on a circuit board, wherein: the active metal layer 1 and the inert electrode layer 2 are connected and located at the periphery of an internal circuit 6; the active metal layer 1 and the inert electrode layer 2 can form a primary cell when in contact with corrosive substances, which is used to intercept the corrosive substances from corroding the internal circuit 6.

[0029] Specifically, the active metal layer 1 and the inert electrode layer 2 are both disposed on the substrate 3 of the circuit board and are located around the internal circuit 6 and spaced apart from the internal circuit 6 .

[0030] The printed circuit board is made of a base plate made of a commonly used polyimide (PI) substrate or other corrosion-resistant materials such as polytetrafluoroethylene. The connected substrate 3 and active metal layer 1 cannot directly form a primary battery when in contact with corrosive substances (the substrate is not conductive). Therefore, this embodiment uses an inert electrode layer 2 located on the substrate 3 to connect with the active metal layer 1. Among them, two different electrodes that can form a primary battery in a corrosive liquid environment can be selected from the above-mentioned active metal layer 1 and the inert electrode layer 2. The inert electrode refers to the activity of the active metal and is not limited to its specific type. For example, the active metal layer 1 can be made of a metal with strong reducing properties such as copper foil or aluminum foil, and the inert electrode layer 2 can be made of a conductive material such as a nickel layer.

[0031] The above-mentioned corrosive substances are usually corrosive liquids that are formed by heat after the equipment has been used for a period of time. For example, a computer in an overheated working environment will produce a certain concentration of sulfide gas or acidic and alkaline corrosive substances that corrode the printed circuit board. The hot gas mixes and condenses to form a corrosive liquid.

[0032] Specifically, the active metal layer 1 and the inert electrode layer 2 include two or more metal layers. The anti-corrosion structure of this embodiment utilizes the anti-corrosion principle of the cathodic protection method of the sacrificial anode (the negative electrode of the galvanic cell); wherein, the active metal layer 1 has strong metal activity and strong reducibility, and forms the negative electrode of the galvanic cell when in contact with the corrosive liquid, and the inert electrode layer 2 forms the positive electrode of the galvanic cell. The active metal layer 1 is consumed by oxidation reaction, and the inert electrode layer 2, as the positive electrode, can avoid corrosion, and the periphery of the internal circuit 6 located on the substrate 3 plays a role in protecting the internal circuit 6. Compared with the existing structure, the anti-corrosion effect in this embodiment is more excellent.

[0033] The anti-corrosion structure of this embodiment is arranged on the periphery of the internal circuit 6 on the circuit board. The connected active metal layer 1 and the inert electrode layer 2 can form a primary battery when in contact with the corrosive liquid. When the circuit board comes into contact with the corrosive substance, the active metal layer 1 is first consumed to react with the corrosive liquid, which is equivalent to the active metal layer 1 first attracting the corrosive liquid, protecting the inert electrode layer 2 and the internal circuit 6, intercepting the corrosive liquid from eroding the internal circuit 6, and not affecting the circuit board to realize its own function, and the anti-corrosion effect is good.

[0034] As an optional implementation, in this embodiment, the active metal layer 1 and the inert electrode layer 2 are arranged in a vertically stacked manner, and / or arranged side by side left and right.

[0035] The active metal layer 1 is connected to the inert electrode layer 2. When in contact with the corrosive liquid, the active metal layer 1 is gradually consumed and protects the inert electrode layer 2 and the internal circuit 6. At the same time, the inert electrode layer 2 covering the substrate 3 also plays a certain protective role.

[0036] Taking into account that the active metal layer 1 reacts and is consumed first when it contacts the corrosive liquid, as an optional implementation, when the active metal layer 1 and the inert electrode layer 2 are arranged stacked up and down, the active metal layer 1 is located on the upper part of the inert electrode layer 2; when the active metal layer 1 and the inert electrode layer 2 are arranged side by side left and right, the active metal layer 1 is located on the side of the inert electrode layer 2 away from the internal circuit 6.

[0037] In this embodiment, copper foil is used as the active metal layer 1 and nickel layer is used as the inert electrode layer 2. Figure 1 As shown, the copper foil is located on the upper part of the nickel layer, and first contacts and reacts with the etching solution, and is gradually consumed, while the nickel layer is located on the substrate 3 and does not participate in the reaction. This prevents the structure from collapsing after the copper foil is consumed in the reaction at the lower part, and ensures the stability of the structure.

[0038] In addition, when the copper foil is located on the side of the nickel layer away from the internal circuit 6, when the corrosive liquid invades from the side of the circuit board, the copper foil first contacts the anti-corrosion liquid and consumes it, and the nickel layer located on the inner side further plays a role of physical interception, thereby improving the anti-corrosion effect. Those skilled in the art can select any arrangement of the anti-corrosion structure according to actual conditions.

[0039] As an alternative embodiment, see Figure 1 and Figure 2 The active metal layer 1 (copper foil) and the inert electrode layer 2 (nickel layer) are located around the internal circuit 6 and are spaced apart from the outermost side of the internal circuit 6 .

[0040] After the corrosive liquid reacts with the copper foil at a certain position, it continues to invade the adjacent copper foil. The gap between the active metal layer 1, the inert electrode layer 2 and the internal circuit 6 prevents the corrosive liquid from directly contacting the internal circuit 6, thereby improving the anti-corrosion effect.

[0041] As an optional embodiment, of the active metal layer 1 and the inert electrode layer 2, at least the width d of the active metal layer 1 in the direction from the side of the circuit board to the internal circuit 6 is ≥ 300 μm (e.g. Figure 2 ).

[0042] See also Figure 1 and Figure 2 As shown, the active metal layer 1 and the inert electrode layer 2 are stacked up and down, and the widths of the two are equal, which can save materials. And the widths d of the active metal layer 1 (copper foil) and the inert electrode layer 2 (nickel layer) both meet the above range. The width of the primary battery electrode within the above numerical range can effectively play an anti-corrosion role, ensuring that there is enough active metal layer 1 to play a protective role.

[0043] As the active metal layer 1 reacts with the corrosive liquid, an oxide film or a hydroxide passivation film is formed on its surface, covering the electrode surface. In view of the above problems, in order to prevent the passivation film from affecting the internal circuit 6, as an optional implementation, see Figure 1 and Figure 2 In the active metal layer 1 and the inert electrode layer 2, at least the active metal layer 1 (copper foil) is intermittently arranged at the periphery of the internal circuit 6. Preferably, the inert electrode layer 2 and the active metal layer 1 are arranged in a corresponding manner and are spaced apart.

[0044] The above structure can form a positive and negative electrode structure with multiple parts. When the corrosive liquid invades, one of the active metal layers 1 (copper foil at a certain position) first contacts the corrosive liquid, reacts with the corrosive liquid first, attracts the corrosive liquid, and consumes it first. As the polarization effect increases, a very thin oxide or hydroxide passivation film protective layer can be quickly generated on the surface to react to the active metal layer 1, so that the active metal layer 1 can resist corrosion from the atmosphere, alkali and certain acids, and the corrosion rate of the active metal layer 1 (copper foil) is slowed down. It is difficult for the corrosive liquid to cross the inert electrode layer 2 (nickel layer). After the copper foil (active metal layer 1) at this position is consumed, the corrosive liquid continues to corrode the next adjacent copper foil.

[0045] The above structure is equivalent to playing the role of "moat" in the internal circuit 6, and multiple points of defense are provided at the periphery of the internal circuit 6 to prevent the corrosion liquid from invading the internal circuit 6. It also prevents the passivation film generated during the reaction from affecting the operation of the internal circuit 6, thereby increasing the service life of the circuit board.

[0046] As an optional implementation, the distance between adjacent active metal layers 1 is smaller than the distance between the active metal layer 1 and the internal circuit 6 .

[0047] Since the distance between adjacent active metal layers 1 in the outer circle is smaller than the distance from the active metal layer 1 to the internal circuit 6, after the active metal layer 1 at a certain position is consumed, the corrosive liquid continues to corrode the next adjacent active metal layer 1 (copper foil) to prevent it from invading the internal circuit 6.

[0048] Example 2

[0049] This embodiment is an improvement on the above embodiment. The active metal layer 1 and the inert electrode layer 2 are located on the periphery of the internal circuit 6 for protection. In order to further improve the anti-corrosion effect, the anti-corrosion structure in this embodiment also includes a waterproof adhesive layer 4, which is at least located on the upper layer and / or lower layer of the internal circuit 6.

[0050] The waterproof adhesive layer 4 can be made of commonly used waterproof and anti-corrosion materials in the prior art, such as transparent optical adhesive, etc., and the specific material is not limited.

[0051] See also Figure 1 As shown, the waterproof adhesive layer 4 includes a lower waterproof adhesive layer 4 located between the substrate 3 and the inert electrode layer 2 and an upper waterproof adhesive layer 4 located on the active metal layer 1 and the internal circuit 6, and the upper and lower parts of the internal circuit 6 have the effect of waterproofing and corrosion prevention.

[0052] As an alternative embodiment, see Figure 1 , the waterproof adhesive layer 4 extends to the periphery of the active metal layer 1.

[0053] like Figure 1 As shown, the waterproof adhesive layer 4 located on the upper layer is filled between the internal circuits 6 and extends to the periphery of the active metal layer 1 and the inert electrode layer 2, and acts as the "first line of defense" for the internal circuits 6 of the circuit board through physical action.

[0054] As an alternative embodiment, see Figure 1 As shown, an insulating layer 5 is also provided on the upper layer of the waterproof adhesive layer 4 .

[0055] The insulating layer 5 is located at the uppermost part of the overall structure and plays an insulating and protective role.

[0056] Example 3

[0057] This embodiment provides a circuit board, including an internal circuit 6 located on a substrate 3 and the above-mentioned anti-corrosion structure.

[0058] The circuit board provided in this embodiment has the above-mentioned anti-corrosion structure, so it also has the advantages of good anti-corrosion performance and long service life. It can be applied to the computer field, touch screen field, etc. Under the condition of relatively harsh working environment, the circuit board of this structure still has high anti-corrosion performance.

[0059] In the description of this specification, specific features, structures or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0060] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An anti-corrosion structure, It is characterized in that The invention comprises an active metal layer and an inert electrode layer arranged on a circuit board, wherein: The active metal layer and the inert electrode layer are connected and are located at the periphery of the internal circuit; the active metal layer and the inert electrode layer can form a galvanic cell when in contact with a corrosive substance, so as to intercept the corrosive substance from corroding the internal circuit; The active metal layer and the inert electrode layer are located around the internal circuit, and are spaced apart from the outermost side of the internal circuit, and are not connected to the internal circuit; Of the active metal layer and the inert electrode layer, at least the active metal layer is intermittently disposed around the periphery of the internal circuit.

2. The anti-corrosion structure according to claim 1, It is characterized in that The active metal layer and the inert electrode layer are arranged vertically and horizontally, and / or arranged side by side.

3. The anti-corrosion structure according to claim 1 or 2, It is characterized in that When the active metal layer and the inert electrode layer are stacked up and down, the active metal layer is located on the upper part of the inert electrode layer; when the active metal layer and the inert electrode layer are arranged side by side, the active metal layer is located on the side of the inert electrode layer away from the internal circuit.

4. The anti-corrosion structure according to claim 1 or 2, It is characterized in that Of the active metal layer and the inert electrode layer, at least the active metal layer has a width d of ≥ 300 μm in the direction from the side of the circuit board to the internal circuit.

5. The anti-corrosion structure according to claim 1, It is characterized in that The distance between adjacent active metal layers is smaller than the distance between the active metal layer and the internal circuit.

6. The anti-corrosion structure according to claim 1 or 2, It is characterized in that The anti-corrosion structure further comprises a waterproof adhesive layer, and the waterproof adhesive layer is at least located on the upper layer and / or the lower layer of the internal circuit.

7. The anti-corrosion structure according to claim 6, It is characterized in that The waterproof adhesive layer extends to the periphery of the active metal layer.

8. The anti-corrosion structure according to claim 6, It is characterized in that An insulating layer is also provided on the upper layer of the waterproof adhesive layer.

9. A circuit board, It is characterized in that The invention comprises an internal circuit located on a substrate and the anti-corrosion structure according to any one of claims 1 to 8.

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