Method for manufacturing mobile phone vibration motor circuit board

Abstract

The present invention discloses a method for manufacturing a mobile phone vibration motor circuit board, comprising the following steps: designing, equidistantly spacing the wire ends on the circuit board on the circuit pattern, setting a solder mask window, the size of the carbon oil pattern being 0.05 mm larger on one side than the solder mask window, and conducting current through a carbon oil strip module; blending the carbon oil, adjusting the resistance of the carbon oil to 300 ± 50 Ω according to the voltage provided to the motor by the mobile phone voltage, and calculating the corresponding square resistance of the carbon oil according to Ohm's law; silk screen printing, evenly applying the blended carbon paste to the exposed copper points of the wire and between two copper points; curing the carbon oil, baking the circuit board to solidify the carbon oil; and applying protective oil, screen printing a layer of solder mask ink on the surface of the carbon oil layer to completely cover and protect the carbon oil. Thus, through the design of the carbon oil pattern, blending, silk screen printing, curing, and applying protective oil, the resistance consistency of the short-distance high-resistance carbon oil can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit boards, and in particular to a method for manufacturing a mobile phone vibration motor circuit board. Background Art

[0002] Mobile phones have become an indispensable electronic gadget in people's lives. All phones have a vibration function, which is achieved through a micro-vibration motor. A mobile phone vibration motor is essentially a micro-motor, consisting of a housing and a rotating shaft mounted therein. The shaft is equipped with bearings and bearing sleeves. The housing also houses the motor components, including magnets, coils, commutator, commutator segments, and carbon brushes. The internal circuit board has six commutator segments, formed by etching copper from the circuit board to form a circle with six gaps. Each commutator segment is connected to a wire coated with insulating ink. The exposed copper at the end of the wire connects the opposite commutator segment through a coating of carbon oil. When the motor is powered, the carbon oil between the wires provides connectivity, stabilizes, and regulates the voltage. The consistency and stability of the carbon film resistance across the short distances between the wires determines the stability of the current flow. Voltage stability affects the motor speed, which in turn affects the frequency and amplitude of the phone's vibration. Abnormal frequency and amplitude directly affect the sound quality of the phone's vibration. Abnormal frequency and amplitude can also accelerate wear of the commutator segment's metal surface, reducing its wear resistance and shortening the motor's lifespan. To achieve the compactness and lightness of mobile phones, the limited internal space required a motor with an even smaller size (8mm outer diameter, 3.4mm thickness). This necessitated refined PCB design, which in turn forced the design of carbon fiber strips to be more compact. Conventional PCB production processes make it difficult to consistently achieve and uniformly control the resistance of small, short-pitch, high-resistance carbon fiber strips. To address these challenges, a process technology was developed to achieve consistent resistance in short-pitch, high-resistance carbon fiber strips. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for manufacturing a mobile phone vibration motor circuit board, which can achieve resistance consistency when manufactured with short-range high-resistance carbon oil.

[0004] A method for manufacturing a mobile phone vibration motor circuit board according to an embodiment of the present invention includes the following steps:

[0005] Design, the spacing between the wire ends on the circuit board is made equal on the circuit pattern, and a 0.2*0.3mm solder mask window is set. The size of the carbon oil pattern is 0.05mm larger than the solder mask window on one side. The carbon oil pattern conducts current through the carbon oil strip module;

[0006] Carbon oil preparation: According to the voltage provided to the motor by the mobile phone voltage, the carbon oil resistance value of the current adjustment is set at 300±50Ω, and the corresponding square resistance carbon oil is calculated according to Ohm's law formula;

[0007] Silk screen printing: Use silk screen printing to evenly apply the prepared carbon paste on the exposed copper points of the conductor and between two copper points;

[0008] Carbon oil curing, baking the circuit board to solidify the carbon oil;

[0009] Protective oil: a layer of solder resist ink is screen printed on the surface of the carbon oil layer to completely cover and protect the carbon oil, protecting it from moisture and changes in resistance caused by friction of carbon powder.

[0010] A method for manufacturing a mobile phone vibration motor circuit board according to an embodiment of the present invention has at least the following beneficial effects: by designing the carbon oil pattern, mixing the carbon oil, silk-screening, curing, and applying protective oil, the resistance consistency of the short-distance high-resistance carbon oil can be achieved.

[0011] According to some embodiments of the present invention, in the "designing" step, three carbon oil strips are provided on the circuit board, and the three carbon oil strips have the same size.

[0012] According to some embodiments of the present invention, in the "silk-screen printing" step, the carbon oil strips located on both sides of the three carbon oil strips are silk-screened in a vertical outward direction.

[0013] According to some embodiments of the present invention, in the "designing" step, the outer edge of the middle carbon fried dough stick among the three carbon fried dough sticks is cut smaller by 0.025 mm.

[0014] According to some embodiments of the present invention, in the "silk screen printing" step, a water film screen is used for the entire board.

[0015] According to some embodiments of the present invention, in the "silk-screen printing" step, the carbon oil is collected every 30 minutes of screen printing to perform a viscosity test on the carbon oil.

[0016] According to some embodiments of the present invention, in the "carbon oil curing" step, the baking plate mode is set to a segmented baking plate from low temperature to high temperature.

[0017] According to some embodiments of the present invention, the method further includes the following steps: testing the resistance of the three carbon oil strips using a multimeter to ensure that the resistance difference between the three carbon oil strips is less than 20Ω.

[0018] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0020] Figure 1 This is a structural diagram of a mobile phone vibration motor circuit board according to an embodiment of the present invention;

[0021] Figure 2 for Figure 1 A top view of a mobile phone vibration motor circuit board is shown;

[0022] Figure 3 This is a flowchart of manufacturing a circuit board according to an embodiment of the present invention.

[0023] Circuit board 100, 1# carbon oil strip 110, 2# carbon oil strip 120, 3# carbon oil strip 130, 4# soldering pad 140, 5# soldering pad 150, 6# soldering pad 160, 7# soldering pad 170, copper point 180. DETAILED DESCRIPTION

[0024] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0025] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0026] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0027] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0028] Reference Figure 1 and Figure 2 According to an embodiment of the present invention, a method for manufacturing a mobile phone vibration motor circuit board includes the following steps:

[0029] Design, the wire head spacing on the circuit board 100 is made equidistant on the circuit pattern, and a 0.2*0.3mm solder mask window is set. The size of the carbon oil pattern is 0.05mm larger than the solder mask window on one side. The carbon oil pattern conducts current through the carbon oil strip module;

[0030] Carbon oil preparation: According to the voltage provided to the motor by the mobile phone voltage, the carbon oil resistance value of the current adjustment is set at 300±50Ω, and the corresponding square resistance carbon oil is calculated according to Ohm's law formula;

[0031] Silk screen printing: Use silk screen printing to evenly apply the prepared carbon paste on the exposed copper points of the conductor and between two copper points;

[0032] Carbon oil curing: baking the circuit board 100 to solidify the carbon oil;

[0033] Protective oil: a layer of solder resist ink is screen printed on the surface of the carbon oil layer to completely cover and protect the carbon oil, protecting it from moisture and changes in resistance caused by friction of carbon powder.

[0034] A method for manufacturing a mobile phone vibration motor circuit board according to an embodiment of the present invention has at least the following beneficial effects: by designing the carbon oil pattern, mixing the carbon oil, silk-screening, curing, and applying protective oil, the resistance consistency of the short-distance high-resistance carbon oil can be achieved.

[0035] According to some embodiments of the present invention, referring to Figure 1 and Figure 2 In the "design" step, three carbon oil strips, namely, 1# carbon oil strip 110, 2# carbon oil strip 120, and 3# carbon oil strip 130, are provided on the circuit board. The three carbon oil strips have the same size. Since the resistance of the carbon oil strip is related to the length, width, thickness and square resistance of the carbon paste, when the square resistance and thickness are consistent, the sizes of the three carbon oil strips are kept consistent, and the resistance of the three carbon oil strips can be kept within the range of ±50Ω.

[0036] According to some embodiments of the present invention, referring to Figure 1 and Figure 2 In the "screen printing" step, the carbon oil strips on both sides of the three carbon oil strips are screen printed in the vertical outward direction, so as to solve the problem of oil seepage caused by the difference between the substrate and the copper foil of the wire end during screen printing, which affects the size and thus the resistance value. It should be noted that the vertical outward direction refers to Figure 2 The center is toward a direction away from the central opening of the circuit board 100.

[0037] According to some embodiments of the present invention, in the "design" step, the outer edge of the middle carbon fried dough stick among the three carbon fried dough sticks is cut down by 0.025 mm to offset the width widening caused by silk screen oil seepage.

[0038] According to some embodiments of the present invention, in the "silk screen printing" step, a water film screen is used for the entire plate, so as to maintain the uniformity of the carbon oil thickness of the entire plate.

[0039] According to some embodiments of the present invention, in the "silk screen printing" step, the carbon oil is collected every 30 minutes of screen printing to test the carbon oil viscosity, so as to facilitate immediate adjustment if there is any deviation, and keep the viscosity within a range to achieve consistency in the thickness of the carbon oil for the screen printing batches.

[0040] According to some embodiments of the present invention, in the "carbon oil curing" step, the baking plate mode is set to a segmented baking plate from low temperature to high temperature to ensure that the carbon oil at the bottom can fully release moisture and solidify.

[0041] According to some embodiments of the present invention, referring to Figure 1 and Figure 2 , further comprising the following steps: testing, using a multimeter to test the resistance of the three carbon oil strips respectively to ensure that the resistance difference between the three carbon oil strips is less than 20Ω. The resistance testing method of the three carbon oil strips is as follows:

[0042] 1# carbon oil strip resistance: Set the multimeter to 2KΩ, touch the two measuring needles to the copper point 180 connected to the 4# soldering pad 140 and the copper point 180 connected to the 5# soldering pad 150 respectively to read the resistance value;

[0043] 2# carbon oil strip resistance: Set the multimeter to 2KΩ, and touch the two measuring needles to the copper point 180 connected to the 4# solder pad 140 and the copper point 180 connected to the 7# solder pad to read the resistance value;

[0044] 3# carbon oil strip resistance: Set the multimeter to 2KΩ, touch the two measuring needles to the copper point connected to the 6# solder pad 160 and the copper point connected to the 7# solder pad 170 respectively to read the resistance value;

[0045] The final requirement is that the resistance difference between the three carbon oil strips should not exceed 20Ω.

[0046] According to some embodiments of the present invention, referring to Figure 3 , the overall production process of the circuit board includes the following steps:

[0047] Material delivery / cutting: TG150 halogen-free 0.13±0.013mm copper-containing H / H sheet, cutting the large material into PNL sheets with a size of 400*400mm;

[0048] Drilling: Drilling is done by mechanical drilling using a drilling machine according to the drill belt designed by the project;

[0049] VCP electroplating: The drilled holes are plated with copper through chemical reaction, and the copper on the surface is thickened;

[0050] Pattern transfer: A photosensitive dry film is attached to the production board, and the pattern on the film is transferred to the dry film through ultraviolet light exposure. The unexposed dry film is then removed through chemical development to expose the copper surface so that it can be etched away and only the pattern remains on the production board.

[0051] Etching: The copper layer exposed on the board is etched away through the chemical reaction of the solution to expose the substrate, leaving the exposed dry film covering the position to form the circuit pattern;

[0052] Stripping: The exposed dry film is removed through the chemical reaction of the solution to reveal the copper wire pattern;

[0053] AOI: Uses optical principles to detect common defects on PCBs after etching;

[0054] Solder mask: Cover the locations where components do not need to be soldered with solder mask ink by screen printing;

[0055] Carbon oil: Use screen printing to evenly apply the prepared carbon paste to the exposed copper points of the conductor and between two copper points;

[0056] Protective oil: a layer of solder mask ink is screen printed on the surface of the carbon oil layer to completely cover the carbon oil for protection;

[0057] Electroplating: Electroplating a nickel-gold layer on the exposed copper area of the circuit board through a replacement reduction reaction;

[0058] Die punching: Make special dies and use high-speed stamping equipment to shape the finished circuit board;

[0059] FQC: Use inspection and testing equipment to confirm the quality of finished products and confirm that they are qualified for shipment;

[0060] Packaging: Packaging of finished products that have passed inspection and testing.

[0061] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. A method for manufacturing a mobile phone vibration motor circuit board, characterized in that: The following steps are involved: Design: The spacing between the wire ends on the circuit board is made equidistant on the circuit pattern, and a 0.2*0.3mm solder mask window is set. The size of the carbon oil pattern is 0.05mm larger than the solder mask window on one side. The carbon oil pattern conducts current through the carbon oil strip module. Three carbon oil strips are set on the circuit board. The three carbon oil strips are of the same size. The outer edge of the carbon oil strip located in the middle of the three carbon oil strips is cut smaller by 0.025mm. Carbon oil preparation: According to the voltage provided to the motor by the mobile phone voltage, the carbon oil resistance value of the current adjustment is set at 300±50Ω, and the corresponding square resistance carbon oil is calculated according to Ohm's law formula; Silk screen printing: Use silk screen printing to evenly apply the prepared carbon paste on the exposed copper points of the conductor and between two copper points; Carbon oil curing, baking the circuit board to solidify the carbon oil; Protective oil: a layer of solder resist ink is screen printed on the surface of the carbon oil layer to completely cover and protect the carbon oil, protecting it from moisture and changes in resistance caused by friction of carbon powder.

2. The method for manufacturing a mobile phone vibration motor circuit board according to claim 1, characterized in that: In the "silk screen printing" step, the carbon fried dough sticks located on both sides of the three carbon fried dough sticks are silk screen printed vertically outward.

3. The method for manufacturing a mobile phone vibration motor circuit board according to claim 1, characterized in that: In the "screen printing" step, a water film drying screen is used for the entire board.

4. The method for manufacturing a mobile phone vibration motor circuit board according to claim 3, characterized in that: During the "screen printing" step, the carbon oil was collected every 30 minutes of screen printing to test the viscosity of the carbon oil.

5. The method for manufacturing a mobile phone vibration motor circuit board according to claim 1, characterized in that: In the "carbon oil curing" step, the baking plate mode is set to a segmented baking plate from low temperature to high temperature.

6. The method for manufacturing a mobile phone vibration motor circuit board according to claim 1, characterized in that: The following steps are also included: Test the resistance of the three carbon oil strips using a multimeter to ensure that the resistance difference between the three carbon oil strips is less than 20Ω.

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