Mobile phone antenna preparation method and mobile phone antenna

Abstract

The invention provides a mobile phone antenna preparation method and a mobile phone antenna. The mobile phone antenna preparation method comprises the following steps that a metal strip is subjected to stamping operation to form an in-mold metal piece, the in-mold metal piece comprises a first stainless steel sheet, a preset metal sheet and a second stainless steel sheet, and the preset metal sheet is clamped and connected between the first stainless steel sheet and the second stainless steel sheet; performing electrophoresis operation on the in-mold metal piece to form a protective layer on the surface of the in-mold metal piece; performing in-mold injection molding on the in-mold metal part to form a metal plastic part; laser etching activation operation is conducted on the metal plastic part, so that a circuit pattern is formed on the metal plastic part; and carrying out chemical plating operation on the metal plastic part to enable the circuit pattern to be attached with a metal layer. The in-mold metal piece adopts a composite structure of stainless steel and the preset metal sheet, so that the weight of the in-mold metal piece is reduced, and a surface protection layer of the in-mold metal piece prevents the preset metal sheet from being corroded in chemical plating operation.

Description

Technical Field

[0001] The present disclosure relates to the field of antenna technology, and in particular to a method for preparing a mobile phone antenna and a mobile phone antenna. Background Art

[0002] Mobile phone in-mold metal parts play an important role in mobile phone design and manufacturing. They not only improve the overall structural strength of the mobile phone, but also meet the needs of aesthetics, heat dissipation, electromagnetic shielding, etc. At present, for the LDS antenna structure parts in the mobile phone industry, in-mold metal parts are mostly made of stainless steel, but due to the high density of stainless steel, the weight of the mobile phone is relatively large, which is not conducive to the lightweight design of the mobile phone.

[0003] In order to solve the above problems, a Chinese patent with publication number CN105261824B discloses a manufacturing process for a mobile phone antenna, which includes the following steps: 1) punching out a main frame section from an aluminum alloy blank; 2) using amorphous alloy powder to form a long liquid metal frame antenna in a frame antenna mold cavity through metal injection molding; 3) connecting the main frame section and the frame antenna to form a mobile phone frame through nano injection molding; 4) using LDS modified plastic to form an LDS antenna bracket at the bottom of the main frame section through nano injection molding; 5) performing laser engraving activation treatment on the LDS antenna area of ​​the LDS antenna bracket, and then chemically plating the activated area to form an LDS antenna.

[0004] The metal parts of the above-mentioned mobile phone antenna are made of aluminum alloy, and the density of aluminum alloy is lower than that of stainless steel, which can reduce the weight of the mobile phone antenna. However, due to the low strength and corrosion resistance of aluminum alloy, the structural strength of the in-mold metal parts of the mobile phone antenna is weakened, and the aluminum of the metal parts will be corroded during the chemical plating process, resulting in a low product yield.

[0005] Therefore, there is an urgent need for a method for preparing a mobile phone antenna and a mobile phone antenna that can reduce weight and have a high product yield. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a method for preparing a mobile phone antenna and a mobile phone antenna.

[0007] The purpose of this disclosure is achieved through the following technical solutions:

[0008] A method for preparing a mobile phone antenna comprises the following steps:

[0009] Performing a stamping operation on the metal strip to form an in-mold metal part, the in-mold metal part comprising a first stainless steel sheet, a pre-set metal sheet and a second stainless steel sheet, the pre-set metal sheet being clamped and connected between the first stainless steel sheet and the second stainless steel sheet, the density of the pre-set metal sheet being less than the density of the first stainless steel sheet or the density of the second stainless steel sheet;

[0010] Performing electrophoresis on the in-mold metal part to form a protective layer on the surface of the in-mold metal part;

[0011] Performing in-mold injection molding on the in-mold metal part to form a metal plastic part;

[0012] Performing a laser engraving activation operation on the metal plastic part so as to form a circuit pattern on the metal plastic part;

[0013] The metal plastic part is subjected to chemical plating so that the circuit pattern is attached with a metal layer to obtain a mobile phone antenna.

[0014] In one embodiment, performing an electrophoresis operation on the in-mold metal part to form a protective layer on the surface of the in-mold metal part includes:

[0015] The in-mold metal part is placed in an energized electrophoresis tank, and the voltage passing through the in-mold metal part is controlled to be 10V-30V, and the current passing through the in-mold metal part is controlled to be 1mA-3mA.

[0016] In one embodiment, the temperature in the electrophoresis tank is controlled at 25°C-35°C.

[0017] In one embodiment, the time for placing the in-mold metal part in the electrophoresis tank is controlled to be 30 minutes to 1 hour.

[0018] In one embodiment, the in-mold metal part is subjected to in-mold injection molding to form a metal plastic part, and the preset metal sheet is an aluminum sheet.

[0019] In one embodiment, the protective layer is an epoxy resin protective layer.

[0020] In one embodiment, the metal plastic part is subjected to chemical plating so that the circuit pattern is attached with a metal layer, comprising:

[0021] Performing a cleaning operation on the metal-plastic part to remove impurities on the surface of the metal-plastic part;

[0022] The metal plastic part is placed in a copper deposition tank so that the circuit pattern is attached with a copper layer.

[0023] In one embodiment, the metal plastic part is subjected to chemical plating so that the circuit pattern is attached with a metal layer, and then the following steps are further included:

[0024] The metal layer is sprayed so that the surface of the metal layer is covered with an insulating protective layer.

[0025] In one embodiment, the metal layer is sprayed so that the surface of the metal layer is covered with an insulating protective layer, and then the following steps are further included:

[0026] The insulating protective layer is cured.

[0027] A mobile phone antenna is prepared by using the mobile phone antenna preparation method described in any of the above embodiments.

[0028] Compared with the prior art, the present invention has at least the following advantages:

[0029] The above-mentioned method for preparing the mobile phone antenna is to first stamp the metal strip to form an in-mold metal part, then perform an electrophoresis operation on the in-mold metal part so that a protective layer is formed on the surface of the in-mold metal part, then perform in-mold injection molding on the in-mold metal part to form a metal plastic part, then perform a laser laser engraving activation operation on the metal plastic part so that a circuit pattern is formed on the metal plastic part, and finally perform a chemical plating operation on the metal plastic part so that a metal layer is attached to the circuit pattern to achieve a conductive effect. Specifically, the in-mold metal part adopts a composite structure in which a first stainless steel sheet, a pre-set metal sheet and a second stainless steel sheet are connected in sequence, and the density of the pre-set metal sheet is less than the density of the first stainless steel sheet or the density of the second stainless steel sheet, that is, the in-mold metal part is not made of all stainless steel. While ensuring the structural strength of the in-mold metal part, the pre-set metal sheet also reduces the weight of the in-mold metal part, and a protective layer is formed on the surface of the in-mold metal part through the electrophoresis operation to prevent the in-mold metal part from being corroded by a strong acid or a strong alkali during the chemical plating operation, thereby improving the yield of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 The present invention is a process flow chart of a method for preparing a mobile phone antenna according to an embodiment. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.

[0033] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0035] The present invention provides a method for preparing a mobile phone antenna, comprising the following steps: performing a stamping operation on a metal strip to form an in-mold metal part, wherein the in-mold metal part comprises a first stainless steel sheet, a preset metal sheet and a second stainless steel sheet, wherein the preset metal sheet is clamped and connected between the first stainless steel sheet and the second stainless steel sheet; performing an electrophoresis operation on the in-mold metal part to form a protective layer on the surface of the in-mold metal part; performing in-mold injection molding on the in-mold metal part to form a metal plastic part; performing a laser engraving activation operation on the metal plastic part to form a circuit pattern on the metal plastic part; and performing a chemical plating operation on the metal plastic part to attach a metal layer to the circuit pattern.

[0036] The above-mentioned method for preparing the mobile phone antenna is to first stamp the metal strip to form an in-mold metal part, then perform an electrophoresis operation on the in-mold metal part so that a protective layer is formed on the surface of the in-mold metal part, then perform in-mold injection molding on the in-mold metal part to form a metal plastic part, then perform a laser laser engraving activation operation on the metal plastic part so that a circuit pattern is formed on the metal plastic part, and finally perform a chemical plating operation on the metal plastic part so that a metal layer is attached to the circuit pattern to achieve a conductive effect. Specifically, the in-mold metal part adopts a composite structure in which a first stainless steel sheet, a pre-set metal sheet and a second stainless steel sheet are connected in sequence, and the density of the pre-set metal sheet is less than the density of the first stainless steel sheet or the density of the second stainless steel sheet, that is, the in-mold metal part is not made of all stainless steel. While ensuring the structural strength of the in-mold metal part, the pre-set metal sheet also reduces the weight of the in-mold metal part, and a protective layer is formed on the surface of the in-mold metal part through the electrophoresis operation to prevent the in-mold metal part from being corroded by a strong acid or a strong alkali during the chemical plating operation, thereby improving the yield of the product.

[0037] In order to better understand the technical solutions and beneficial effects of the present invention, the present invention is further described in detail below in conjunction with specific embodiments:

[0038] like Figure 1 As shown, a method for preparing a mobile phone antenna in one embodiment includes the following steps:

[0039] S100: stamping a metal strip to form an in-mold metal part, wherein the in-mold metal part comprises a first stainless steel sheet, a pre-set metal sheet and a second stainless steel sheet, wherein the pre-set metal sheet is clamped and connected between the first stainless steel sheet and the second stainless steel sheet, and a density of the pre-set metal sheet is less than a density of the first stainless steel sheet or a density of the second stainless steel sheet.

[0040] In this embodiment, the metal strip is pre-stamped to form a three-layer structure, which includes a first stainless steel sheet, a pre-set metal sheet and a second stainless steel sheet, and the pre-set metal sheet is clamped and connected between the first stainless steel sheet and the second stainless steel sheet to ensure the structural strength of the two ends of the in-mold metal part. Since the pre-set metal sheet is used in the middle, the density of the pre-set metal sheet is lower than that of stainless steel, which can reduce the weight of the in-mold metal part. Furthermore, the thickness of the pre-set metal sheet is greater than the thickness of the first stainless steel sheet or the second stainless steel sheet. For example, the total thickness of the in-mold metal part is 0.25 mm, the thickness of the first stainless steel sheet is 0.05 mm, the thickness of the second stainless steel sheet is 0.05 mm, and the thickness of the pre-set metal sheet is 0.15 mm, which can significantly reduce the weight of the in-mold metal part.

[0041] S200: performing an electrophoresis operation on the in-mold metal part to form a protective layer on the surface of the in-mold metal part.

[0042] In this embodiment, the stamped and cut in-mold metal parts are placed in an electrophoretic tank, in which there is an electrophoretic fluid, which contains organic matter, solvents, additives and other substances. After the electrophoretic tank is energized, since the in-mold metal parts are made of metal material, stainless steel and metal have good conductivity and high conductivity. Under the action of an external electric field, organic particles are adsorbed to the surface of the in-mold metal parts to form a dense protective layer (i.e., a coating film). The coating film has corrosion resistance and wear resistance, and can protect the underlying pre-set metal sheet from being corroded by the plating solution during the electroplating process.

[0043] S300: performing in-mold injection molding on the in-mold metal part to form a metal plastic part.

[0044] In this embodiment, the in-mold metal part is placed in the injection mold to perform in-mold injection molding. When the injection molding equipment is started, the plastic particles are formed into a plastic bracket in the injection mold. Since the in-mold metal part is located in the injection mold, the plastic bracket and the in-mold metal part are formed as one piece, that is, the metal plastic part includes the plastic bracket and the in-mold metal part, and the plastic bracket is used to be installed in the mobile phone housing.

[0045] S400: performing a laser engraving activation operation on the metal plastic part to form a circuit pattern on the metal plastic part.

[0046] In this embodiment, the metal plastic part is placed in a laser engraving device and laser etched using a specific laser power. Since the plastic support of the metal plastic part is a modified plastic of an organic metal complex, when the laser is irradiated on the plastic support, the organic metal complex releases particles, activating the irradiated area to form a circuit pattern, providing a chemical reaction basis for chemical plating, thereby forming a circuit interconnected structure on the surface of the plastic support.

[0047] S500: performing chemical plating on the metal plastic part so that a metal layer is attached to the circuit pattern to obtain a mobile phone antenna.

[0048] In this embodiment, the metal plastic part is placed in a strong alkaline solution or a strong acidic solution. The solution contains metal ions. Under the action of the catalyst and the conductor, the metal ions obtain electrons in the circuit pattern, so that the metal ions form a metal element and adhere to the circuit pattern, and form a continuous metal layer on the circuit pattern, thereby making the metal layer on the circuit pattern have a conductive effect.

[0049] The above-mentioned method for preparing the mobile phone antenna is to first stamp the metal strip to form an in-mold metal part, then perform an electrophoresis operation on the in-mold metal part so that a protective layer is formed on the surface of the in-mold metal part, then perform in-mold injection molding on the in-mold metal part to form a metal plastic part, then perform a laser laser engraving activation operation on the metal plastic part so that a circuit pattern is formed on the metal plastic part, and finally perform a chemical plating operation on the metal plastic part so that a metal layer is attached to the circuit pattern to achieve a conductive effect. Specifically, the in-mold metal part adopts a composite structure in which a first stainless steel sheet, a pre-set metal sheet and a second stainless steel sheet are connected in sequence, and the density of the pre-set metal sheet is less than that of the first stainless steel sheet or the second stainless steel sheet, that is, the in-mold metal part is not made of all stainless steel. While ensuring the structural strength of the in-mold metal part, the pre-set metal sheet also reduces the weight of the in-mold metal part, and a protective layer is formed on the surface of the in-mold metal part through the electrophoresis operation to prevent the in-mold metal part from being corroded by a strong acid or a strong alkali during the chemical plating operation, thereby improving the yield of the product.

[0050] In one embodiment, performing an electrophoresis operation on the in-mold metal part to form a protective layer on the surface of the in-mold metal part includes:

[0051] The in-mold metal part is placed in an energized electrophoresis tank, and the voltage passing through the in-mold metal part is controlled to be 10V-30V, and the current passing through the in-mold metal part is controlled to be 1mA-3mA.

[0052] It is understandable that the voltage and current passing through the in-mold metal part affect the thickness, uniformity and adhesion of the protective layer. Therefore, the voltage and current of the in-mold metal part need to be controlled within a certain range. In this embodiment, the in-mold metal part is placed in an energized electrophoresis tank, and the in-mold metal part is detected using a current detector or a voltage detector. When it is detected that the current or voltage passing through the in-mold metal part exceeds a preset value, the current or voltage input into the electrophoresis tank is adjusted, thereby adjusting the current or voltage passing through the in-mold metal part.

[0053] In one embodiment, the temperature in the electrophoresis tank is controlled at 25°C-35°C.

[0054] It is understandable that the temperature affects the quality and performance of the protective layer. When the temperature of the electrophoresis tank is too high, the organic matter and other substances in the electrophoresis liquid are prone to lose their activity, which leads to the inability to form a protective layer on the surface of the metal parts in the mold. When the temperature of the electrophoresis tank is low, the organic matter and other substances in the electrophoresis liquid are less active, and the quality of the protective layer formed is poor, which can not well protect the metal parts in the mold. Therefore, it is necessary to control the temperature in the electrophoresis tank. In this embodiment, a thermometer is provided in the electrophoresis tank to detect the temperature of the electrophoresis tank. When the temperature of the electrophoresis tank exceeds the range, the electrophoresis liquid in the electrophoresis tank is cooled or heated.

[0055] In one embodiment, the time for placing the in-mold metal part in the electrophoresis tank is controlled to be 30 minutes to 1 hour.

[0056] It is understandable that the metal parts in the mold can have a protective effect by forming a dense thin protective layer on the surface. If the metal parts in the mold react for a long time in the electrophoresis tank, the thickness of the protective layer formed is relatively large, resulting in material waste of the electrophoresis liquid and increased production costs. If the metal parts in the mold react for a short time in the electrophoresis tank, the thickness of the protective layer formed is relatively thin and sparse, and the protection effect on the metal parts in the mold is poor. Therefore, it is necessary to control the electrophoresis time of the metal parts in the mold.

[0057] In one embodiment, the pre-set metal sheet is an aluminum sheet. It is understandable that the density of the aluminum sheet is less than that of the stainless steel sheet, which reduces the weight of the metal part in the mold. However, since the corrosion resistance of the aluminum sheet is lower than that of the stainless steel sheet, it is necessary to perform electrophoresis before chemical plating to form a protective layer on the surface of the metal part in the mold. Furthermore, in other embodiments, the pre-set metal sheet can also be other metals with a density less than or equal to that of aluminum, such as magnesium, lithium and other metals.

[0058] In one embodiment, the protective layer is an epoxy resin protective layer. In this embodiment, after the electrophoresis is completed, an epoxy resin protective layer is formed on the surface of the in-mold metal part to isolate the in-mold metal part from strong acids and alkalis during the chemical plating process. In another embodiment, the protective layer can also be an acrylate resin protective layer.

[0059] In one embodiment, the metal plastic part is subjected to chemical plating so that the circuit pattern is attached with a metal layer, comprising:

[0060] Performing a cleaning operation on the metal-plastic part to remove impurities on the surface of the metal-plastic part;

[0061] The metal plastic part is placed in a copper deposition tank so that the circuit pattern is attached with a copper layer.

[0062] In this embodiment, the metal plastic parts need to be cleaned before chemical plating to remove impurities, oil stains, dust and other pollutants formed after laser engraving, so as to ensure that the coating can be evenly and densely attached to the surface of the metal plastic parts. The steps for cleaning the metal plastic parts are as follows: first, clean the metal plastic parts with clean water or solvent to remove most of the oil stains and impurities on the surface of the metal plastic parts; then, use ultrasonic cleaning equipment to clean the metal plastic parts. Ultrasonic cleaning can use the impact force generated by the explosion of tiny bubbles generated by high-frequency vibration on the surface of the metal plastic parts to peel off tiny pollutants from the surface of the metal plastic parts, thereby achieving a deep cleaning effect; finally, rinse the metal plastic parts with deionized water to remove residual cleaning agents and impurities to ensure that the surface of the metal plastic parts is clean and free of dirt.

[0063] Furthermore, the cleaned metal and plastic parts are placed in a copper plating tank for chemical copper plating. The copper plating tank contains a strong alkaline solution or a strong acidic solution. The solution contains copper ions. Under the action of the catalyst and the conductor, the copper ions obtain electrons in the circuit pattern, so that the copper element adheres to the circuit pattern to achieve a conductive effect.

[0064] In one embodiment, the metal plastic part is subjected to chemical plating so that the circuit pattern is attached with a metal layer, and then the following steps are further included:

[0065] The metal layer is sprayed so that the surface of the metal layer is covered with an insulating protective layer.

[0066] In this embodiment, a metal layer is attached to the circuit pattern, but since the metal layer after chemical plating is relatively fragile and easily corroded by the external environment, an insulating protective layer is sprayed on the surface of the metal layer to prevent the metal layer from being oxidized, corroded or worn.

[0067] In one embodiment, the metal layer is sprayed so that the surface of the metal layer is covered with an insulating protective layer, and then the following steps are further included:

[0068] The insulating protective layer is cured.

[0069] In this embodiment, the surface of the metal layer is covered with an insulating protective layer by spraying. At this time, the insulating protective layer needs to be cured, that is, the paint on the surface of the metal layer is dried to ensure that the paint can firmly adhere to the surface of the metal layer to form the required insulating protective layer. Furthermore, the curing treatment is to heat or irradiate the metal plastic part with ultraviolet light to accelerate the curing reaction of the paint, so that the paint is firmly attached to the surface of the metal layer to prevent the paint from falling off or cracking.

[0070] It is understandable that the pre-set metal sheet is located between the first stainless steel sheet and the second stainless steel sheet, and the corrosion resistance of the pre-set metal sheet is poorer than that of the stainless steel sheet. Therefore, it is necessary to improve the adhesion of the protective layer at the pre-set metal sheet so that the protective layer is better attached to the pre-set metal sheet. In one embodiment, the in-mold metal part is subjected to electrophoresis to form a protective layer on the surface of the in-mold metal part, and the process also includes:

[0071] The in-mold metal part is subjected to a roughening treatment to roughen the surface of the in-mold metal part.

[0072] In this embodiment, since the surface of the in-mold metal part is relatively smooth, the bonding force between the protective layer formed during electrophoresis and the in-mold metal part is poor, causing the protective layer to fall off easily. Therefore, the surface of the in-mold metal part is roughened by physical or chemical methods. The physical method is to use corundum to physically impact the pre-set metal sheet of the in-mold metal part so that pits are formed on the surface of the pre-set metal sheet. During electrophoresis, the organic particles in the electrophoresis liquid are better adsorbed on the pits on the surface of the pre-set metal sheet, so that the bonding force between the protective layer and the pre-set metal sheet is stronger. Furthermore, in another embodiment, the surface of the pre-set metal sheet is roughened by a chemical method, that is, by coating an etching solution on the surface of the pre-set metal sheet, the etching solution reacts with the pre-set metal sheet, so that pits are formed on the surface of the pre-set metal sheet, thereby making the bonding force between the protective layer and the pre-set metal sheet stronger.

[0073] It can be understood that in order to further improve the bonding force between the in-mold metal part and the protective layer, in one embodiment, the in-mold metal part is subjected to electrophoresis operation to form a protective layer on the surface of the in-mold metal part, and the method also includes:

[0074] Pre-treating the in-mold metal part;

[0075] Performing phosphating treatment on the metal parts in the mold;

[0076] Carrying out water washing treatment on the metal parts in the mold;

[0077] The metal part in the mold is dried.

[0078] In this embodiment, the in-mold metal parts are first pretreated, specifically, ultrasonic cleaning is performed on the in-mold metal parts to remove oil stains and impurities on the surface of the in-mold metal parts to ensure the quality of the phosphating film generated in the phosphating treatment; then, the in-mold metal parts after the pretreatment are immersed in the phosphating solution. After the in-mold metal parts react with the phosphating solution for a period of time, the oxides on the surface of the in-mold metal parts are converted into a phosphate layer, thereby forming a dense phosphoric acid film on the surface of the in-mold metal parts. The phosphoric acid film improves the physical and chemical properties of the surface of the in-mold metal parts to improve the corrosion resistance of the in-mold metal parts. At the same time, the phosphoric acid film can also enhance the bonding force between the protective layer and the surface of the in-mold metal parts, so that the protective layer is more firmly attached to the surface of the in-mold metal parts and is not easy to fall off; then, the in-mold metal parts after the phosphating treatment are washed with water to remove the residual phosphating solution and impurities on the surface of the in-mold metal parts; finally, the in-mold metal parts are dried, that is, the in-mold metal parts are dried using a drying device to ensure that the phosphating film is completely cured.

[0079] It is understandable that when performing in-mold injection molding, if the protective layer formed is thick, the mold is easy to crush and damage the protective layer, which makes the pre-set metal sheet in the subsequent chemical plating process easy to be corroded. Therefore, the thickness of the protective layer needs to be tested before performing in-mold injection molding. In one embodiment, the in-mold metal part is subjected to in-mold injection molding to form a metal plastic part, which also includes:

[0080] Obtaining the actual thickness value of the protective layer;

[0081] Matching the actual thickness value of the protective layer with the preset thickness value;

[0082] When the actual thickness of the protective layer is greater than the preset thickness, the height of the cushion block of the injection mold is increased to control the mold clamping amount of the injection mold.

[0083] In this embodiment, the thickness of the protective layer of the metal part in the mold is first detected before the injection molding, and the steps of obtaining the actual thickness value of the protective layer are as follows: first, the thickness of the metal part in the mold before electrophoresis is measured to obtain a first thickness value, and then, the thickness of the metal part in the mold after electrophoresis is measured to obtain a second thickness value, and the difference between the second thickness value and the first thickness value is the actual thickness value of the protective layer. Further, the range of the preset thickness value is set to 25μm-35μm. When the actual thickness value of the protective layer is greater than the preset thickness value, it indicates that the thickness of the protective layer formed on the surface of the metal part in the mold is relatively large. By increasing the height of the pad of the injection mold, that is, the pad of the injection mold can be detached and replaced, and the pad is located between the movable mold and the fixed mold of the injection mold, the increase in the height of the pad increases the volume of the injection cavity formed by the movable mold and the fixed mold, thereby preventing the protective layer from being crushed when the mold is closed.

[0084] In other embodiments, the actual thickness value of the protective layer is matched with the preset thickness value, and then the method further includes:

[0085] When the actual thickness of the protective layer is less than the preset thickness, the height of the cushion block of the injection mold is lowered to control the mold clamping amount of the injection mold.

[0086] In this embodiment, the actual thickness of the protective layer detected is less than the preset thickness value, that is, the actual thickness of the protective layer at this time is less than 25μm-35μm, indicating that the thickness of the protective layer formed by the metal part in the mold is relatively small. When the injection mold is closed, the gap between the metal part in the mold and the mold is relatively large, resulting in processing deviations in the metal plastic parts formed by injection molding, which in turn leads to a decrease in product yield. Therefore, before injection molding, it is necessary to reduce the height of the pad of the injection mold, that is, to use a pad with a smaller height. Since the pad is located between the movable mold and the fixed mold of the injection mold, the reduction in the height of the pad also reduces the volume of the injection cavity formed by the movable mold and the fixed mold, so that the mold fits tightly with the metal part in the mold when the mold is closed, thereby eliminating processing deviations.

[0087] Furthermore, due to the reduction in the height of the cushion block, the volume of the injection cavity formed between the movable mold and the fixed mold is also reduced accordingly, which means that the amount of plastic that can be injected into the injection cavity at this time is also reduced accordingly, that is, the amount of injection is low, and the thickness of the plastic part formed accordingly is also reduced. In this way, when a high-power laser is used for laser engraving activation operation, the laser can easily burn through the glue layer directly and then burn through the protective layer under the glue layer, thus resulting in a decrease in the yield rate. Therefore, before performing laser laser engraving activation, it is necessary to detect the power of the laser. In one embodiment, when the actual thickness value of the protective layer is less than the preset thickness value, the cushion block height of the injection mold is reduced to control the mold clamping amount of the injection mold, and then it also includes:

[0088] Get the real-time laser power of laser activation operation;

[0089] Detecting whether the real-time laser power is greater than or equal to a preset laser power;

[0090] When the real-time laser power is greater than or equal to the preset laser power, the value of the real-time laser power is reduced, and the working time of the laser engraving activation is extended.

[0091] In this embodiment, the actual thickness of the protective layer is less than the preset thickness. Since the height of the pad needs to be lowered, the volume of the injection cavity is correspondingly reduced, so that the injection volume is also reduced. If the preset laser power continues to work, it is easy to burn through the plastic layer or even the protective layer, resulting in a decrease in product yield. Therefore, it is necessary to adjust the real-time laser power. First, the real-time laser power of the laser engraving activation operation is obtained. The real-time laser power at this time is the power of the last laser engraving activation operation; then, the real-time laser power is matched with the preset laser power. The preset laser power is the safety power, that is, the laser working power corresponding to the standard thickness of the protective layer. When the preset laser power is working, the protective layer or the plastic layer can be prevented from being burned through; then, when the real-time laser power obtained is greater than or equal to the preset laser power, it indicates that the real-time laser power at this time is large and it is easy to burn through the protective layer or the plastic layer. Therefore, it is necessary to reduce the real-time laser power at this time so that the real-time laser power is less than or equal to the preset laser power, and extend the working time of the adjusted real-time laser power. For example, the preset laser power working time is 1s. At this time, the working time of the adjusted real-time laser power is extended to 1.2s to ensure that the laser can form a circuit pattern on the metal plastic part, and at the same time, it can also prevent the plastic layer or the protective layer from being burned through.

[0092] In another embodiment, when the real-time laser power is less than the preset laser power, the value of the real-time laser power is increased, and the working time of laser engraving activation is shortened.

[0093] In the present embodiment, the detected real-time laser power is less than the preset laser power, indicating that the real-time laser power at this time is less than the safety power of the laser. It can be understood that the principle of laser engraving (LDS laser) is to add non-conductive organic metal compounds into the LDS material, and the laser processing makes the organic bonds of the metal compounds be broken up, and the metal atoms are separated and attached to the plastic surface. That is, when the real-time laser power is small, the laser energy is insufficient to break up the organic bonds of the metal compounds, that is, the circuit pattern cannot be formed on the plastic layer. Therefore, the value of the real-time laser power at this time is increased to make the real-time laser power energy higher, so as to break up the organic bonds of the metal compounds, and at the same time shorten the activation working time of the laser engraving to avoid the laser burning through the plastic layer, that is, to ensure that the circuit pattern is stably formed on the metal plastic part, and at the same time protect the plastic layer of the metal plastic part.

[0094] The present application also provides a mobile phone antenna, which is prepared by the mobile phone antenna preparation method described in any of the above embodiments. The mobile phone antenna preparation method includes the following steps: stamping a metal strip to form an in-mold metal part, the in-mold metal part includes a first stainless steel sheet, a pre-set metal sheet and a second stainless steel sheet, the pre-set metal sheet is clamped and connected between the first stainless steel sheet and the second stainless steel sheet; electrophoresis is performed on the in-mold metal part to form a protective layer on the surface of the in-mold metal part; in-mold injection molding is performed on the in-mold metal part to form a metal plastic part; laser engraving activation is performed on the metal plastic part to form a circuit pattern on the metal plastic part; chemical plating is performed on the metal plastic part to attach a metal layer to the circuit pattern.

[0095] Compared with the prior art, the present invention has at least the following advantages:

[0096] The above-mentioned method for preparing the mobile phone antenna is to first stamp the metal strip to form an in-mold metal part, then perform an electrophoresis operation on the in-mold metal part so that a protective layer is formed on the surface of the in-mold metal part, then perform in-mold injection molding on the in-mold metal part to form a metal plastic part, then perform a laser laser engraving activation operation on the metal plastic part so that a circuit pattern is formed on the metal plastic part, and finally perform a chemical plating operation on the metal plastic part so that a metal layer is attached to the circuit pattern to achieve a conductive effect. Specifically, the in-mold metal part adopts a composite structure in which a first stainless steel sheet, a pre-set metal sheet and a second stainless steel sheet are connected in sequence, that is, the in-mold metal part is not made of all stainless steel. While ensuring the structural strength of the in-mold metal part, the pre-set metal sheet also reduces the weight of the in-mold metal part, and a protective layer is formed on the surface of the in-mold metal part through the electrophoresis operation to prevent the in-mold metal part from being corroded by a strong acid or a strong alkali during the chemical plating operation, thereby improving the yield of the product.

[0097] The above-mentioned embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure shall be based on the attached claims.

Claims

1. A method for preparing a mobile phone antenna, characterized in that: The following steps are involved: Performing a stamping operation on the metal strip to form an in-mold metal part, the in-mold metal part comprising a first stainless steel sheet, a pre-set metal sheet and a second stainless steel sheet, the pre-set metal sheet being clamped and connected between the first stainless steel sheet and the second stainless steel sheet, the density of the pre-set metal sheet being less than the density of the first stainless steel sheet or the density of the second stainless steel sheet; Performing electrophoresis on the in-mold metal part to form a protective layer on the surface of the in-mold metal part; Performing in-mold injection molding on the in-mold metal part to form a metal plastic part; Performing a laser engraving activation operation on the metal plastic part so as to form a circuit pattern on the metal plastic part; The metal plastic part is subjected to chemical plating so that the circuit pattern is attached with a metal layer to obtain a mobile phone antenna.

2. The method for preparing a mobile phone antenna according to claim 1, characterized in that: Performing an electrophoresis operation on the in-mold metal part to form a protective layer on the surface of the in-mold metal part includes: The in-mold metal part is placed in an energized electrophoresis tank, and the voltage passing through the in-mold metal part is controlled to be 10V-30V, and the current passing through the in-mold metal part is controlled to be 1mA-3mA.

3. The method for preparing a mobile phone antenna according to claim 2, characterized in that: The temperature in the electrophoresis tank is controlled at 25°C-35°C.

4. The method for preparing a mobile phone antenna according to claim 2, characterized in that: The time for placing the in-mold metal part in the electrophoresis tank is controlled to be 30 minutes to 1 hour.

5. The method for preparing a mobile phone antenna according to claim 1, characterized in that: The preset metal sheet is an aluminum sheet.

6. The method for preparing a mobile phone antenna according to claim 1, characterized in that: The protective layer is an epoxy resin protective layer.

7. The method for preparing a mobile phone antenna according to claim 1, characterized in that: The metal plastic part is subjected to chemical plating so that the circuit pattern is attached with a metal layer, comprising: Performing a cleaning operation on the metal-plastic part to remove impurities on the surface of the metal-plastic part; The metal plastic part is placed in a copper deposition tank so that the circuit pattern is attached with a copper layer.

8. The method for preparing a mobile phone antenna according to claim 1, characterized in that: The metal plastic part is subjected to chemical plating operation so that the circuit pattern is attached with a metal layer, and then the following steps are further included: The metal layer is sprayed so that the surface of the metal layer is covered with an insulating protective layer.

9. The method for preparing a mobile phone antenna according to claim 8, characterized in that: The metal layer is sprayed so that the surface of the metal layer is covered with an insulating protective layer, and then the following steps are further included: The insulating protective layer is cured.

10. A mobile phone antenna, characterized in that: The mobile phone antenna is prepared by the method for preparing the mobile phone antenna according to any one of claims 1 to 9.

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