Preparation method of alloy chip resistor and alloy chip resistor

Abstract

The invention provides a preparation method of an alloy chip resistor and the alloy chip resistor, and belongs to the technical field of electronic components, and the preparation method comprises the following steps: S1, forming a resistor metal body from a first plate, and forming an electrode metal body from a second plate; s2, electrode metal bodies serve as electrodes to be welded to the two ends of the upper surface and / or the two ends of the lower surface of the resistor metal body respectively, the electrodes at the two ends of the same surface are separated from each other, and in the welding process, welding points of all the electrodes are determined according to the resistance value of the resistor metal body so that the resistance value can be adjusted to reach a preset target range; s3, coating the surface with an insulating layer, and exposing an electrode surface; and S4, making an identification code on the surface, and carrying out surface treatment on the electrode surface to prepare the alloy chip resistor. The beneficial effects are that a welding and resistance adjusting integrated process is adopted, a resistance adjusting step is omitted, and the cost is reduced; and meanwhile, the manufacturing size and the processing technology are not limited, and the size can be further reduced, so that the resistor has a longer service life.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic components, and in particular to a method for preparing an alloy chip resistor and an alloy chip resistor prepared by the preparation method. Background Art

[0002] With the continuous development of electronic circuit technology, circuit integration has become an important trend in the development of the modern electronic industry. Driven by this trend, alloy chip resistors, as the most common and most versatile passive components in circuits, have been widely used in many fields such as computers, consumer electronics, medical electronics, industrial electronics, automotive electronics, home appliances, and power tools. With the increasing speed of product updates in these fields, higher requirements are placed on the performance of alloy chip resistors, such as high power handling capacity, high-precision resistance control, high reliability, and good environmental adaptability.

[0003] In order to meet market demand, alloy chip resistor manufacturers continue to explore and improve production processes to simplify production processes, reduce production losses, thereby achieving cost reduction and efficiency improvement, and improving product competitiveness. At present, the common high-power and high-precision chip alloy resistors on the market, such as 1206, 2512, 2818, 4527 and other specifications, mainly use a relatively mature manufacturing process. For example, Chinese patent CN106952702A discloses a metal plate structure high-power and high-resistance precision chip resistor manufacturing process and chip resistor. The process includes bonding the alloy resistor with the metal electrode, setting the resistor body width according to Ohm's law, forming the resistor body frame by stamping, cutting, etc., and then cutting off one end of the metal electrode, and then adjusting the resistance by mechanical grinding, laser ablation, etc., and then the resistor unit is wrapped with an insulating layer, and the non-welding surface of the insulating layer is marked with a code, and the exposed electrodes at both ends are electroplated with nickel tin.

[0004] However, this traditional process still has many limitations. First, the basic material of the traditional process is a joint of an alloy and a metal electrode, which has limitations in the thickness of the alloy, and it is usually difficult to achieve less than 0.3 mm, which seriously restricts the research and development and production capabilities of high-resistance products. Secondly, the cost of the joint material is high, and a lot of waste is generated during the frame forming process, making it difficult to control the product cost. In addition, the traditional process requires a special resistance adjustment process, which is relatively inefficient, has a long processing cycle, and is more expensive. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for preparing an alloy chip resistor; on the other hand, it also provides an alloy chip resistor.

[0006] The technical problem solved by the present invention can be achieved by adopting the following technical solutions:

[0007] The first aspect of the present invention is to provide a method for preparing an alloy chip resistor, comprising:

[0008] Step S1, forming a resistor metal body with a first preset size from a first plate, and forming an electrode metal body with a second preset size from a second plate;

[0009] Step S2, the electrode metal body is used as an electrode and welded to the two ends of the upper surface and / or the two ends of the lower surface of the resistor metal body, and the electrodes at the two ends of the same surface are separated from each other, wherein during the welding process, the welding points of each electrode are determined according to the resistance value of the resistor metal body, so as to adjust the resistance value to a preset target range, thereby forming a precise resistor body component;

[0010] Step S3, coating the upper and lower surfaces of the precision resistor component with an insulating layer, and exposing the electrode surface of each electrode to form a precision plastic package;

[0011] Step S4, making an identification code on the upper surface of the precision plastic package body, and performing surface treatment on the electrode surface of each of the electrodes to prepare an alloy chip resistor.

[0012] Preferably, the material of the first plate is any one or more combinations of manganese-copper alloy, nickel-chromium alloy, iron-chromium alloy, copper-antimony alloy and copper-chromium alloy.

[0013] Preferably, the second plate is made of a single metal or a plated metal.

[0014] Preferably, the step S1 further comprises: forming a heat sink having a third preset size from a third plate;

[0015] After step S2 and before step S3, the following further includes:

[0016] Step S2.1, attaching the heat sink to the upper surface and / or lower surface of the resistor metal body through an adhesive layer, and the heat sink is electrically isolated from the resistor metal body;

[0017] In the step S3, the surfaces of the precision resistor component and the heat sink are covered with an insulating layer, and the electrode surface of the electrode is exposed to form the precision plastic package.

[0018] Preferably, the third plate material is any one or more combinations of copper foil, aluminum foil, copper-based alloy foil and aluminum alloy foil.

[0019] Preferably, the material of the bonding layer is any one or more combinations of liquid epoxy resin, acrylic resin, polyurethane, silicone and two-liquid mixed hardening glue.

[0020] Preferably, in step S2, determining the welding point of each electrode according to the resistance value of the resistor metal body comprises:

[0021] Step S21, pressing the measuring needle of the resistance meter onto the electrodes at both ends of the same surface of the resistor metal body to measure the resistance between the welding points of the electrodes at both ends in real time;

[0022] Step S22, fine-tuning the welding positions and welding point areas of the welding points of the electrodes at both ends according to the resistance value measured in real time, so as to adjust the resistance value to the preset target range.

[0023] Preferably, the material of the insulating layer is any one or more combinations of liquid epoxy resin, acrylic resin, polyurethane, silicone and two-liquid mixed hardening glue.

[0024] The second aspect of the present invention is to provide an alloy chip resistor, which is prepared by the above-mentioned preparation method, comprising:

[0025] Resistor metal body;

[0026] An electrode metal body, wherein the electrode metal body is welded as electrodes at both ends of the upper surface and / or the lower surface of the resistor metal body, and the electrodes at both ends of the same surface are separated from each other, wherein during the welding process, the welding points of each electrode are determined according to the resistance value of the resistor metal body to adjust the resistance value to a preset target range, thereby forming a precise resistor body component;

[0027] An insulating layer, covering the upper and lower surfaces of the precision resistor component and exposing the electrode surface of each of the electrodes, wherein a surface treatment layer is formed on the electrode surface;

[0028] The identification code is made on the upper surface of the precision plastic packaging body.

[0029] Preferably, it also includes:

[0030] A heat sink, the heat sink is adhered to the upper surface and / or lower surface of the resistor metal body through an adhesive layer, and the heat sink is electrically isolated from the resistor metal body;

[0031] The insulating layer covers the surfaces of the precision resistor component and the heat sink.

[0032] The advantages or beneficial effects of the technical solution of the present invention are:

[0033] The present invention adopts an integrated welding and resistance adjustment process. During the welding process, the welding point is determined and fine-tuned according to the resistance value of the resistor metal body to achieve the purpose of accurately fine-tuning the resistance to the target range, eliminating the resistance adjustment step, simplifying the preparation process, and reducing costs. At the same time, the resistor metal body is formed from the first plate material and the electrode metal body is formed from the second plate material. Compared with the traditional process in which the joint of the alloy and the metal electrode is used as the basic material, the manufacturing size and processing technology are not restricted, the size can be further reduced, and the resistor has a better service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of a preparation method in a preferred embodiment of the present invention;

[0035] Figure 2 This is a flow chart of step S2 in a preferred embodiment of the present invention;

[0036] Figure 3 It is a cross-sectional schematic diagram of an alloy chip resistor (single-sided electrode) in a preferred embodiment 1 of the present invention;

[0037] Figure 4 It is a cross-sectional schematic diagram of an alloy chip resistor (double-sided electrode) in a preferred embodiment 2 of the present invention;

[0038] Figure 5 A schematic diagram of a process for preparing a bonding heat sink in a preferred embodiment of the present invention;

[0039] Figure 6 It is a cross-sectional schematic diagram of an alloy chip resistor in a preferred embodiment 3 of the present invention;

[0040] Figure 7 It is a cross-sectional schematic diagram of an alloy chip resistor in a preferred embodiment 4 of the present invention;

[0041] Figure 8 The figure is a schematic flow chart of the preparation method in a preferred embodiment of the present invention.

[0042] Description of reference numerals:

[0043] 1. Resistor metal body; 2a. First electrode; 2b. Second electrode; 2c. Third electrode; 2d. Fourth electrode; 3a. First welding point; 3b. Second welding point; 3c. Third welding point; 3d. Fourth welding point; 4a. First insulating layer; 4b. Second insulating layer; 5a. First soldering pad; 5b. Second soldering pad; 5c. Third soldering pad; 5d. Fourth soldering pad; 6. Adhesive layer; 7. Heat sink; 7a. First heat sink; 7b. Second heat sink. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0046] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0047] like Figures 1 to 4 As shown, in a preferred embodiment of the present invention, based on the above problems existing in the prior art, a method for preparing an alloy chip resistor is provided, comprising:

[0048] Step S1, forming a resistor metal body 1 with a first preset size from a first plate, and forming an electrode metal body with a second preset size from a second plate;

[0049] Step S2, the electrode metal body is welded as an electrode at both ends of the upper surface and / or the lower surface of the resistor metal body 1, and the electrodes at both ends of the same surface are separated from each other, wherein during the welding process, the welding points of each electrode are determined according to the resistance value of the resistor metal body 1, so as to adjust the resistance value to a preset target range, thereby forming a precise resistor body component;

[0050] Step S3, covering the upper and lower surfaces of the precision resistor component with an insulating layer, and exposing the electrode surface of each electrode to form a precision plastic package;

[0051] Step S4, making an identification code on the upper surface of the precision plastic package body, and performing surface treatment on the electrode surface of each electrode to form a pad, so as to prepare an alloy chip resistor.

[0052] Specifically, in order to address the problems of low efficiency, long processing cycle and rising costs caused by the separate resistance adjustment process in traditional processes, in this embodiment, an integrated welding resistance adjustment process is adopted. During the welding process, the welding points are determined and fine-tuned according to the resistance value of the resistor metal body 1, so as to achieve the purpose of accurately fine-tuning the resistance to the target range, thereby eliminating the independent resistance adjustment step, greatly simplifying the production process and effectively reducing costs.

[0053] At the same time, the traditional process relies on the alloy and metal electrode joint body as the basic material. The thickness of the joint body is limited (usually not less than 0.3mm), which seriously restricts the production capacity of high resistance products. At the same time, this joint body is not only expensive, but also generates a large amount of waste during the frame forming process, making product cost control extremely difficult. In this embodiment, a plurality of resistor metal bodies 1 of fixed size can be formed on the same first plate, and a plurality of electrode metal bodies of fixed size can be formed on the same second plate. Compared with the traditional process using the alloy and metal electrode joint body as the basic material, this embodiment is no longer restricted in manufacturing size and processing technology, and can further realize the miniaturization of the product, which can be suitable for batch and large-scale production of resistors. At the same time, it can reduce the generation of waste and achieve product cost control.

[0054] As a preferred embodiment, the material of the first plate is any one or more combinations of manganese-copper alloy, nickel-chromium alloy, iron-chromium alloy, copper-antimony alloy and copper-chromium alloy.

[0055] Specifically, the material of the first plate and the resistor metal body 1 formed by it can be manganese-copper alloy, nickel-chromium alloy, iron-chromium alloy, copper-antimony alloy or copper-chromium alloy. That is, the first plate is an alloy plate, which can be a complete rectangular sheet or coil, and its thickness is between 50μm and 500μm.

[0056] The first plate is punched or cut to form a plurality of resistor metal bodies 1 of fixed size. Compared with the traditional process using a joint of an alloy and a metal electrode as the basic material, this breaks away from the limitations of manufacturing size and processing technology and can further reduce the size of the resistor metal body 1. It is also suitable for mass production of resistors.

[0057] As a preferred embodiment, the material of the second plate is a single metal or a metal containing a coating.

[0058] Specifically, the second plate and the electrode metal body formed therefrom are made of a single metal with low resistivity or a metal containing a coating, including but not limited to a copper sheet, a nickel sheet, a nickel-plated copper sheet or a silver-plated copper sheet, etc., and the thickness thereof is between 50 and 500 μm.

[0059] The second plate is punched or cut to form a plurality of electrode metal bodies of fixed size. Compared with the traditional process using the joint of alloy and metal electrode as the basic material, it gets rid of the limitation of manufacturing size and processing technology, and can further reduce the size of electrode metal body; at the same time, it can be suitable for mass production of resistors.

[0060] As a preferred embodiment, wherein Figure 2 As shown, in step S2, determining the welding points of each electrode according to the resistance value of the resistor metal body 1 includes:

[0061] Step S21, pressing the measuring needle of the resistance meter onto the electrodes at both ends of the same surface of the resistor metal body 1 to measure the resistance between the welding points of the electrodes at both ends in real time;

[0062] Step S22, based on the resistance value measured in real time, fine-tune the welding position and welding point area of ​​the welding points of the electrodes at both ends to adjust the resistance value to a preset target range.

[0063] Specifically, compared with the conventional process in which the electrode metal body and the resistor metal body 1 are usually connected by electroplating, in this embodiment, the electrical connection between the electrode metal body and the resistor metal body 1 is made by welding rather than the common electroplating process on the market.

[0064] The welding process can use laser welding, electron beam welding, arc welding and the like to electrically connect the two.

[0065] The electrode metal bodies are placed on the resistor metal body 1 by laser welding, electron beam welding or arc welding, and are distributed on the left and right ends of the upper surface and / or the lower surface to form electrodes separated from each other.

[0066] During welding, press the probe of the ohmmeter onto the electrodes at the left and right ends of the upper and / or lower surfaces to detect the resistance value in real time. By fine-tuning the welding position and area of ​​the welding point, the resistance can be precisely adjusted to the target range.

[0067] According to the conductor resistance law formula:

[0068] R=ρL / S

[0069] Wherein, ρ represents the resistivity of the resistor metal body 1, L represents the length of the resistor metal body 1, that is, the distance between the welding points on the electrodes at both ends; S represents the cross-sectional area of ​​the resistor metal body 1, and R represents the resistance value detected in real time between the welding points.

[0070] According to the above formula, after determining the resistivity ρ and cross-sectional area S of the resistor metal body 1, the spacing L between the welding points on the electrodes at both ends is fine-tuned within a preset range. Generally, it is adjusted from large to small, that is, the resistor component can be precisely fine-tuned to the target resistance value, thereby forming a precise resistor component.

[0071] As a preferred embodiment, the material of the insulating layer is any one or more combinations of liquid epoxy resin, acrylic resin, polyurethane, silicone and two-liquid mixed hardening (AB) glue.

[0072] Specifically, the insulating layer materials used in traditional processes are mostly solid epoxy resins. This type of material is a simple epoxy resin with a relatively large molecular weight and a thermoplastic solid oligomer. Its thermal conductivity is relatively low, generally in the range of 1.0-1.5W / (m·K), resulting in poor heat dissipation performance of the device, insufficient heat dissipation of the device, and significant surface temperature rise, thereby limiting the power and reliability of the product.

[0073] In this embodiment, the insulating layer uses materials including but not limited to liquid epoxy resin, acrylic resin, polyurethane, silicone or AB glue, which improves the thermal conductivity of the insulating layer material and thereby improves the heat dissipation performance and reliability of the device.

[0074] Furthermore, thermal conductive materials or other fillers may be added to the insulating layer material to further improve the performance of the device. The thermal conductive material may include but is not limited to aluminum oxide, aluminum nitride, silicon oxide, etc.

[0075] The embodiment of the present invention uses liquid colloidal material as the insulating coating layer, and the colloidal material can be added with thermal conductive materials such as aluminum oxide, aluminum nitride, silicon oxide, and other fillers, and the thermal conductivity of the colloidal material can be as high as 3.0W / (m·K) or more. After curing, it has high temperature resistance, high thermal conductivity, chemical resistance, and good mechanical and electrical insulation properties.

[0076] Furthermore, in step S3, coating the insulating layer means that the precise resistor component is coated with the insulating layer by dispensing, printing, injection molding or high-temperature pressing, and then the insulating layer is cured by a high-temperature oven, UV, IR, etc. to enhance the hardness and bonding strength of the insulating layer to form a precise plastic package.

[0077] Furthermore, in step S4, the identification code on the surface of the insulating layer can be screen printed, laser-coded, spray-coded, etc. The insulating layer covers the resistor metal body 1 and the electrode metal body, and only the electrode surfaces of the two electrodes are exposed. The electrode surfaces of the exposed electrodes can be surface-treated by electroplating nickel, electroplating tin, or electroplating nickel tin, etc., and used as solder pads.

[0078] Furthermore, the alloy chip resistor prepared by the above-mentioned preparation method comprises:

[0079] Resistor metal body 1;

[0080] Electrode metal body, the electrode metal body is welded as electrodes at both ends of the upper surface and / or both ends of the lower surface of the resistor metal body 1, and the electrodes at both ends of the same surface are separated from each other, wherein, during the welding process, the welding points of each electrode are determined according to the resistance value of the resistor metal body 1, so as to adjust the resistance value to a preset target range, thereby forming a precise resistor body component;

[0081] An insulating layer covers the upper and lower surfaces of the precision resistor component and exposes the electrode surface of each electrode, and a surface treatment layer is formed on the electrode surface;

[0082] The identification code is made on the upper surface of the precision plastic package.

[0083] Two specific embodiments are provided below to illustrate the above alloy chip resistor and its preparation method:

[0084] Embodiment 1

[0085] like Figure 3 As shown, the device of the embodiment of the present invention is a single-sided electrode device, that is, it is composed of a resistive metal body 1, a first electrode 2a and a second electrode 2b, a first welding point 3a and a second welding point 3b, a first insulating layer 4a and a second insulating layer 4b, and a first pad 5a and a second pad 5b. The preparation method thereof includes the following steps:

[0086] Step A1: a manganese-copper alloy plate with a thickness of 0.4 mm is selected as the base material of the resistor metal body, and is punched into a small rectangular resistor metal body 1 with a size of 6 mm*3 mm. The resistivity of the alloy material is 0.44 μΩ·m; and

[0087] A copper sheet with a thickness of 0.3 mm is selected as the base material of the electrode metal body, and is punched into an electrode metal body of 3 mm*1 mm;

[0088] Step A2: Select two electrode metal bodies as the first electrode 2a and the second electrode 2b, place them under the resistor metal body 1 and distribute them at the left and right ends, and realize electrical connection between the electrode metal body and the resistor metal body 1 by laser welding to form the first electrode 2a and the second electrode 2b separated from each other;

[0089] During welding, the distance between the first welding point 3a corresponding to the first electrode 2a at the left end and the second welding point 3b corresponding to the second electrode 2b at the right end is controlled within the range of 5.3mm to 5.6mm. According to the resistance value of the resistor metal body detected in real time, the position of the welding point is adjusted in real time to make the resistance value of the resistor assembly within the range of 1.98mΩ to 2.02mΩ. The precision of the precision resistor assembly (including the resistor metal body 1, the first electrode 2a and the second electrode 2b) is ±1%;

[0090] Step A3: Arrange the precision resistor components on the auxiliary tooling template in an array at a spacing of 6.3mm*3.1mm, select a liquid epoxy resin glue with high heat resistance and high thermal conductivity, and the thermal conductivity of the glue is 3.5W / (m·K). Through the glue dispensing process, wrap the precision resistor components on the auxiliary template to form a first insulating layer 4a located on the upper surface of the precision resistor component and a second insulating layer 4b located on the lower surface of the precision resistor component. The second insulating layer 4b is flush with the surface of the first electrode 2a and the second electrode 2b, and only the electrode surfaces of the first electrode 2a and the second electrode 2b are exposed. After curing the glue at 100°C for 2 hours, the precision plastic package is separated from the auxiliary tooling template;

[0091] Step A4: Cut the precision plastic package into 6.3mm*3.1mm units;

[0092] Step A5: Laser coding is performed on the front side of the unit body (i.e., the side of the precision plastic package body facing away from the first electrode 2a and the second electrode 2b) to mark the specifications of the product. In addition, the electrode surfaces of the two electrodes of the unit body are surface treated by electroplating nickel tin, and a corresponding surface treatment layer is formed on the electrode surface of the first electrode 2a as the first welding pad 5a, and a corresponding surface treatment layer is formed on the electrode surface of the second electrode 2b as the second welding pad 5b.

[0093] Step A6: Finally, 2512 packaging, 2mΩ, 1% accuracy are performed to prepare a new type of surface mounted alloy chip resistor that does not require resistance adjustment.

[0094] Embodiment 2

[0095] The embodiment of the present invention provides an alloy chip resistor and a method for preparing the same. The difference from the first embodiment is that the first embodiment is a single-sided electrode device, while the second embodiment is a double-sided electrode device. Figure 3 As shown, the device is composed of a resistive metal body 1, first to fourth electrodes (2a, 2b, 2c, 2d), first to fourth welding points (3a, 3b, 3c, 3d), a first insulating layer 4a and a second insulating layer 4b, and first to fourth pads (5a, 5b, 5c, 5d). The preparation method thereof comprises the following steps:

[0096] Step B1: punching a 0.4 mm thick manganese-copper alloy plate into a 6 mm*3 mm small rectangular resistor metal body 1, wherein the resistivity of the alloy material is 0.44 μΩ·m; and

[0097] A copper sheet with a thickness of 0.3 mm is punched into an electrode metal body with a size of 3 mm*1 mm;

[0098] Step B2: Select two electrode metal bodies as the first electrode 2a and the second electrode 2b, place them below the resistor metal body 1 and distribute them at the left and right ends, and realize the electrical connection between the electrode metal body and the resistor metal body 1 by laser welding, so as to form the first electrode 2a and the second electrode 2b separated from each other; select two electrode metal bodies as the third electrode 2c and the fourth electrode 2d, place them above the resistor metal body 1 and distribute them at the left and right ends, and realize the electrical connection between the electrode metal body and the resistor metal body 1 by laser welding, so as to form the third electrode 2c and the fourth electrode 2d separated from each other;

[0099] During the welding process, the spacing between the first welding point 3a corresponding to the first electrode 2a at the left end of the lower part of the resistor metal body 1 and the second welding point 3b corresponding to the second electrode 2b at the right end is controlled within the range of 5.3mm to 5.6mm. According to the resistance value of the resistor metal body detected in real time, the position of the welding point is adjusted in real time to make the resistance value of the resistor body component within the range of 1.98mΩ to 2.02mΩ. Similarly, the welding position and welding point area of ​​the third welding point 3c corresponding to the third electrode 2c and the fourth welding point 3d corresponding to the fourth electrode 2d are controlled in the same manner to achieve the purpose of accurately fine-tuning the resistance to the target range.

[0100] The precision of the precision resistor component (including the resistor metal body 1, the first electrode 2a, the second electrode 2b, the third electrode 2c, and the fourth electrode 2d) is ±1%;

[0101] Step B3: Arrange the precision resistor components on the auxiliary tooling template in an array at a spacing of 6.3mm*3.1mm, select a liquid epoxy resin glue with high heat resistance and high thermal conductivity, and the thermal conductivity of the glue is 3.5W / (m·K). Through the glue dispensing process, the precision resistor components on the auxiliary template are wrapped to form a first insulating layer 4a located on the upper surface of the precision resistor component and a second insulating layer 4b located on the lower surface of the precision resistor component. The first insulating layer 4a is flush with the surface of the third electrode 2c and the fourth electrode 2d, and the second insulating layer 4b is flush with the surface of the first electrode 2a and the second electrode 2b, and only the electrode surfaces of the first electrode 2a, the second electrode 2b, the third electrode 2c and the fourth electrode 2d are exposed. After curing the glue at 100°C for 2 hours, the precision plastic package is separated from the auxiliary tooling template;

[0102] Step B4: cutting the precision plastic package into 6.3mm*3.1mm unit bodies;

[0103] Step B5: Laser coding is performed on the two surfaces of the unit body, namely, the plastic package body between the first electrode 2a and the second electrode 2b and the plastic package body between the third electrode 2c and the fourth electrode 2d, to mark the specifications of the product. In addition, the electrode surfaces of the four electrodes of the unit body are surface treated by electroplating nickel tin, and a corresponding surface treatment layer is formed on the electrode surface of the first electrode 2a as a first welding pad 5a, a corresponding surface treatment layer is formed on the electrode surface of the second electrode 2b as a second welding pad 5b, a corresponding surface treatment layer is formed on the electrode surface of the third electrode 2c as a third welding pad 5c, and a corresponding surface treatment layer is formed on the electrode surface of the fourth electrode 2d as a fourth welding pad 5d.

[0104] Step B6: Finally, 2512 packaging, 2mΩ, 1% accuracy, and a new double-sided mounted and non-adjustable alloy chip resistor are prepared.

[0105] like Figures 5 to 7 As shown, the present invention also provides a method for preparing an alloy chip resistor, which differs from the first and second embodiments in that: step S1 further includes: forming a heat sink 7 having a third preset size from a third plate;

[0106] After step S2 and before step S3, the method further includes:

[0107] Step S2.1, affixing the heat sink to the upper surface and / or lower surface of the resistor metal body through the adhesive layer 6, and the heat sink 7 is electrically isolated from the resistor metal body;

[0108] In step S3, the surfaces of the precision resistor component and the heat sink 7 are covered with an insulating layer, and the electrode surfaces of the electrodes are exposed to form a precision plastic package.

[0109] Specifically, in this embodiment, in order to further enhance the heat dissipation performance of the device, a heat sink 7 is added to the device. The heat sink 7 is adhered to the upper surface and / or lower surface of the resistor metal body through an adhesive layer 6. The heat sink is electrically isolated from the electrode metal body and the resistor metal body. The external insulating layer covers the precision resistor body assembly together with the heat dissipation layer, leaving only the electrode exposed and used as a pad.

[0110] The heat sink and the resistor body, as well as the heat sink and the electrode body are all electrically isolated.

[0111] As a preferred embodiment, the material of the third plate material is any one or more combinations of copper foil, aluminum foil, copper-based alloy foil, and aluminum alloy foil.

[0112] Specifically, in this embodiment, a plurality of heat sinks 7 of fixed sizes can be formed on the same third plate, which can be suitable for batch and large-scale production of resistors.

[0113] As a preferred embodiment, the material of the bonding layer is any one or more combinations of liquid epoxy resin, acrylic resin, polyurethane, silicone and two-liquid mixed hardening glue.

[0114] Specifically, in this embodiment, the bonding layer uses materials including but not limited to liquid epoxy resin, acrylic resin, polyurethane, silicone or AB glue to improve the thermal conductivity of the bonding layer material, thereby improving the heat dissipation performance and reliability of the device.

[0115] Bonding the heat sink means applying adhesive material on the precision resistor body by dispensing or printing, placing the heat sink on the adhesive material, and then curing it through a high-temperature oven, UV, IR, etc. to combine the two.

[0116] Furthermore, a thermal conductive material or other filler may be added to the bonding layer material to further improve the performance of the device. The thermal conductive material may include but is not limited to aluminum oxide, aluminum nitride, silicon oxide, etc.

[0117] As a preferred embodiment, the invention further comprises:

[0118] The heat sink 7 is adhered to the upper surface and / or lower surface of the resistor metal body 1 through the adhesive layer 6, and the heat sink 7 is electrically isolated from the resistor metal body 1;

[0119] The insulating layer is coated on the surface of the precision resistor component and the heat sink 7 .

[0120] Regardless of single-sided electrodes or double-sided electrodes, a heat sink 7 can be added to improve the heat dissipation efficiency of the component and increase the power of the component.

[0121] Two specific embodiments are provided below to illustrate the above alloy chip resistor and its preparation method:

[0122] Embodiment 3

[0123] like Figure 6 As shown, an embodiment of the present invention provides an alloy chip resistor and a preparation method thereof, which differs from the first embodiment in that a heat sink is added to improve the heat dissipation performance of the device.

[0124] The device is a single-sided electrode device, namely, it is composed of a resistive metal body 1, a first electrode 2a and a second electrode 2b, a first welding point 3a and a second welding point 3b, a first insulating layer 4a and a second insulating layer 4b, a first welding pad 5a and a second welding pad 5b, an adhesive layer 6, and a heat sink 7. The preparation method thereof comprises the following steps:

[0125] Step C1: A manganese-copper alloy plate with a thickness of 0.4 mm is selected as the base material of the resistor metal body, and is punched into a small rectangular resistor metal body 1 with a size of 6 mm*3 mm. The resistivity of the alloy material is 0.44 μΩ·m;

[0126] A copper sheet with a thickness of 0.3 mm is selected as the base material of the electrode metal body, and is punched into an electrode metal body with a size of 3 mm*1 mm; and

[0127] Aluminum foil with a thickness of 0.1 mm is selected and punched into a heat sink 7 with a size of 6 mm*3 mm;

[0128] Step C2: Select two electrode metal bodies as the first electrode 2a and the second electrode 2b, place them under the resistor metal body 1 and distribute them at the left and right ends, and realize electrical connection between the electrode metal body and the resistor metal body 1 by laser welding to form the first electrode 2a and the second electrode 2b separated from each other;

[0129] During welding, the distance between the first welding point 3a corresponding to the first electrode 2a at the left end and the second welding point 3b corresponding to the second electrode 2b at the right end is controlled within the range of 5.3mm to 5.6mm. According to the resistance value of the resistor metal body detected in real time, the position of the welding point is adjusted in real time to make the resistance value of the resistor assembly within the range of 1.98mΩ to 2.02mΩ. The precision of the precision resistor assembly (including the resistor metal body 1, the first electrode 2a and the second electrode 2b) is ±1%;

[0130] Step C3: Arrange the precision resistor components on the auxiliary tooling template in an array at a pitch of 6.3 mm*3.1 mm, select a liquid epoxy resin glue with high heat resistance and high thermal conductivity, and the thermal conductivity of the glue is 3.5 W / (m·K), and form a bonding layer 6 on the top of the resistor metal body 1 through a dispensing process, and then place the heat sink 7 on the bonding layer 6, and combine the two by curing the glue at 100°C for 2 hours;

[0131] Step C4: Use the epoxy resin glue to wrap the precision resistor component to which the heat sink has been bonded on the auxiliary template through a dispensing process to form a first insulating layer 4a located on the upper surface of the precision resistor component and a second insulating layer 4b located on the lower surface of the precision resistor component. The second insulating layer 4b is flush with the surfaces of the first electrode 2a and the second electrode 2b, and only the electrode surfaces of the first electrode 2a and the second electrode 2b are exposed. After curing the glue at 100°C for 2 hours, the precision plastic package is separated from the auxiliary tooling template;

[0132] Step C5: cutting the precision plastic package into 6.3mm*3.1mm unit bodies;

[0133] Step C6: Laser coding is performed on the front side of the unit body (i.e., the side of the precision plastic package body facing away from the first electrode 2a and the second electrode 2b) to mark the specifications of the product. In addition, the electrode surfaces of the two electrodes of the unit body are surface treated by electroplating nickel tin, and a corresponding surface treatment layer is formed on the electrode surface of the first electrode 2a as the first welding pad 5a, and a corresponding surface treatment layer is formed on the electrode surface of the second electrode 2b as the second welding pad 5b.

[0134] Step C7: Finally, 2512 packaging, 2mΩ, 1% accuracy, and a new type of alloy chip resistor with low temperature rise, high power, and surface mountability and no need for resistance adjustment are prepared.

[0135] Embodiment 4

[0136] The embodiment of the present invention provides an alloy chip resistor and a method for preparing the same, which is different from the first embodiment in that the third embodiment is a single-sided electrode device, while the fourth embodiment is a double-sided electrode device. Figure 7 As shown, the device is composed of a resistive metal body 1, first to fourth electrodes (2a, 2b, 2c, 2d), first to fourth welding points (3a, 3b, 3c, 3d), a first insulating layer 4a and a second insulating layer 4b, first to fourth welding pads (5a, 5b, 5c, 5d), and a first heat sink 7a and a second heat sink 7b. The preparation method thereof comprises the following steps:

[0137] Step D1: A manganese-copper alloy plate with a thickness of 0.4 mm is selected as the base material of the resistor metal body, and is punched into a small rectangular resistor metal body 1 with a size of 6 mm*3 mm. The resistivity of the alloy material is 0.44 μΩ·m;

[0138] A copper sheet with a thickness of 0.3 mm is selected as the base material of the electrode metal body, and is punched into an electrode metal body with a size of 3 mm*1 mm; and

[0139] Select aluminum foil with a thickness of 0.1 mm and punch it into a 3 mm*3 mm heat sink;

[0140] Step D2: Select two electrode metal bodies as the first electrode 2a and the second electrode 2b, place them below the resistor metal body 1 and distribute them at the left and right ends, and realize the electrical connection between the electrode metal body and the resistor metal body 1 by laser welding, so as to form the first electrode 2a and the second electrode 2b separated from each other; select two electrode metal bodies as the third electrode 2c and the fourth electrode 2d, place them above the resistor metal body 1 and distribute them at the left and right ends, and realize the electrical connection between the electrode metal body and the resistor metal body 1 by laser welding, so as to form the third electrode 2c and the fourth electrode 2d separated from each other;

[0141] During the welding process, the spacing between the first welding point 3a corresponding to the first electrode 2a at the left end of the lower part of the resistor metal body 1 and the second welding point 3b corresponding to the second electrode 2b at the right end is controlled within the range of 5.3mm to 5.6mm. According to the resistance value of the resistor metal body detected in real time, the position of the welding point is adjusted in real time to make the resistance value of the resistor body component within the range of 1.98mΩ to 2.02mΩ. Similarly, the welding position and welding point area of ​​the third welding point 3c corresponding to the third electrode 2c and the fourth welding point 3d corresponding to the fourth electrode 2d are controlled in the same manner to achieve the purpose of accurately fine-tuning the resistance to the target range.

[0142] The precision of the precision resistor component (including the resistor metal body 1, the first electrode 2a, the second electrode 2b, the third electrode 2c, and the fourth electrode 2d) is ±1%;

[0143] Step D3: Arrange the precision resistor components on the auxiliary tooling template in an array at a pitch of 6.3 mm*3.1 mm, select a liquid epoxy resin glue with high heat resistance and high thermal conductivity, and the thermal conductivity of the glue is 3.5 W / (m·K), and form a first bonding layer and a second bonding layer (not shown in the figure) above and below the resistor metal body 1 through a dispensing process, and then place the first heat sink 7a on the first bonding layer, and place the second heat sink 7b on the second bonding layer, and combine the two by curing the glue at 100°C for 2 hours, and the first heat sink 7a and the second heat sink 7b are electrically isolated from the resistor metal body 1 and the four electrodes;

[0144] Step D4: Use the epoxy resin glue to wrap the precision resistor component to which the heat sink has been bonded on the auxiliary template through a dispensing process, forming a first insulating layer 4a located on the upper surface of the precision resistor component and a second insulating layer 4b located on the lower surface of the precision resistor component, wherein the first insulating layer 4a is flush with the surfaces of the third electrode 2c and the fourth electrode 2d, and the second insulating layer 4b is flush with the surfaces of the first electrode 2a and the second electrode 2b, and only the electrode surfaces of the first electrode 2a, the second electrode 2b, the third electrode 2c and the fourth electrode 2d are exposed. After curing the colloid at 100°C for 2 hours, the precision plastic package is separated from the auxiliary tooling template;

[0145] Step D5: cutting the precision plastic package into unit bodies of 6.3 mm*3.1 mm;

[0146] Step D6: Laser coding is performed on the two surfaces of the unit body, namely, the plastic package body between the first electrode 2a and the second electrode 2b and the plastic package body between the third electrode 2c and the fourth electrode 2d, to mark the specifications of the product. In addition, the electrode surfaces of the four electrodes of the unit body are surface treated by electroplating nickel tin, and a corresponding surface treatment layer is formed on the electrode surface of the first electrode 2a as a first welding pad 5a, a corresponding surface treatment layer is formed on the electrode surface of the second electrode 2b as a second welding pad 5b, a corresponding surface treatment layer is formed on the electrode surface of the third electrode 2c as a third welding pad 5c, and a corresponding surface treatment layer is formed on the electrode surface of the fourth electrode 2d as a fourth welding pad 5d.

[0147] Step D7: Finally, 2512 packaging, 2mΩ, 1% accuracy, and a new type of alloy chip resistor with low temperature rise, high power, and surface mountable and no resistance adjustment are prepared.

[0148] like Figure 8 As shown, the embodiment of the present invention uses pure alloy plate as the basic material, and uses a welding and resistance adjustment integrated process to weld the resistor metal body and the electrode metal body. In the welding process, the position and area of ​​the welding point are precisely controlled to form a precise resistor body component, thereby omitting the separate resistance adjustment step in the traditional process. Subsequently, an insulating layer with high temperature resistance, high thermal conductivity and good electrical insulation is used to form a precise plastic package, and after electroplating pad treatment, an alloy chip resistor is finally prepared.

[0149] Furthermore, after joining to the precision resistor component and before coating the insulating layer, an optional step can be added: bonding the heat sink. By adding the heat sink, the heat dissipation efficiency of the device can be further improved, ensuring its long-term stable operation.

[0150] The prepared alloy chip resistor has the characteristics of low cost, simple processing, high power, low TCR and low surface temperature, which makes the resistor have a better service life. Moreover, the manufacturing size and processing technology are not limited, and the size can be further reduced.

[0151] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of this specification and illustrations should be included in the protection scope of the present invention.

Claims

1. A method for preparing an alloy chip resistor, characterized in that: include: Step S1, forming a resistor metal body with a first preset size from a first plate, and forming an electrode metal body with a second preset size from a second plate; Step S2, the electrode metal body is used as an electrode and welded to the two ends of the upper surface and / or the two ends of the lower surface of the resistor metal body, and the electrodes at the two ends of the same surface are separated from each other, wherein during the welding process, the welding points of each electrode are determined according to the resistance value of the resistor metal body, so as to adjust the resistance value to a preset target range, thereby forming a precise resistor body component; Step S3, coating the upper and lower surfaces of the precision resistor component with an insulating layer, and exposing the electrode surface of each electrode to form a precision plastic package; Step S4, making an identification code on the upper surface of the precision plastic package body, and performing surface treatment on the electrode surface of each of the electrodes to prepare an alloy chip resistor.

2. The preparation method according to claim 1, characterized in that: The material of the first plate is any one or more combinations of manganese-copper alloy, nickel-chromium alloy, iron-chromium alloy, copper-antimony alloy and copper-chromium alloy.

3. The preparation method according to claim 1, characterized in that: The second plate is made of a single metal or a plated metal.

4. The preparation method according to claim 1, characterized in that: The step S1 further includes: forming a heat sink having a third preset size from a third plate; After step S2 and before step S3, the following further includes: Step S2.1, attaching the heat sink to the upper surface and / or lower surface of the resistor metal body through an adhesive layer, and the heat sink is electrically isolated from the resistor metal body; In the step S3, the surfaces of the precision resistor component and the heat sink are covered with an insulating layer, and the electrode surface of the electrode is exposed to form the precision plastic package.

5. The preparation method according to claim 4, characterized in that: The third plate material is any one or more combinations of copper foil, aluminum foil, copper-based alloy foil and aluminum alloy foil.

6. The preparation method according to claim 4, characterized in that: The material of the bonding layer is any one or more combinations of liquid epoxy resin, acrylic resin, polyurethane, silicone and two-liquid mixed hardening glue.

7. The preparation method according to claim 1, characterized in that: In the step S2, determining the welding point of each electrode according to the resistance value of the resistor metal body includes: Step S21, pressing the measuring needle of the resistance meter onto the electrodes at both ends of the same surface of the resistor metal body to measure the resistance between the welding points of the electrodes at both ends in real time; Step S22, fine-tuning the welding positions and welding point areas of the welding points of the electrodes at both ends according to the resistance value measured in real time, so as to adjust the resistance value to the preset target range.

8. The preparation method according to claim 1, characterized in that: The material of the insulating layer is any one or more combinations of liquid epoxy resin, acrylic resin, polyurethane, silicone and two-liquid mixed hardening glue.

9. An alloy chip resistor, characterized in that: The method is prepared by any one of claims 1 to 8, comprising: Resistor metal body; An electrode metal body, wherein the electrode metal body is welded as electrodes at both ends of the upper surface and / or the lower surface of the resistor metal body, and the electrodes at both ends of the same surface are separated from each other, wherein during the welding process, the welding points of each electrode are determined according to the resistance value of the resistor metal body to adjust the resistance value to a preset target range, thereby forming a precise resistor body component; An insulating layer, covering the upper and lower surfaces of the precision resistor component and exposing the electrode surface of each of the electrodes, wherein a surface treatment layer is formed on the electrode surface; The identification code is made on the upper surface of the precision plastic packaging body.

10. The alloy chip resistor according to claim 9, characterized in that: Also includes: A heat sink, the heat sink is adhered to the upper surface and / or lower surface of the resistor metal body through an adhesive layer, and the heat sink is electrically isolated from the resistor metal body; The insulating layer covers the surfaces of the precision resistor component and the heat sink.

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