Preparation method of chip module

Abstract

The invention relates to the technical field of chip module preparation, and particularly discloses a preparation method of a chip module, which comprises the following steps: firstly, mixing Mn304 of a component A, Co2O3 of a component B, Ni0 of a component C and Fe2O3 of a component D, ball-milling, roasting and dehydrating to obtain a dry ball-milled raw material, secondly, uniformly mixing the ball-milled raw material with an adhesive to obtain chip slurry, then pressing the chip slurry into a sheet, and finally preparing the chip module. The preparation method comprises the following steps: preparing a thin sheet, roasting the thin sheet, polishing two surfaces of the roasted thin sheet to obtain a blank sheet, and finally sintering the blank sheet at the temperature of 1280-1300 DEG C to obtain the chip module. Through the synergistic compounding effect of all the components, the thickness of the manufactured chip module is increased, double-sided polishing can be conveniently carried out on the chip module, the smoothness and consistency of the surface of the chip module are ensured, resistance drift caused by performance change of a resistor in the long-term working process is prevented, the chip module is not prone to breakdown when current repeatedly passes through the chip module, and the service life of the chip module is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of chip module preparation, and in particular to a method for preparing a chip module. Background Art

[0002] The chip module is an important component for information data transmission. Currently, two or more oxides of metals such as manganese, copper, silicon, cobalt, iron, nickel, zinc, etc. are usually used as durable materials for chip module preparation. During preparation, they are first fully mixed, molded, and sintered to obtain a chip, and then the chip is fixed to a pair of electrodes to finally prepare a chip module. The chip module obtained by the above preparation method is particularly susceptible to current breakdown or aging drift when current passes through it repeatedly, thereby reducing its service life and having poor durability. Summary of the invention

[0003] The object of the present invention is to provide a method for preparing a chip module, thereby improving the durability of the chip module and extending its service life.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention provides a method for preparing a chip module, comprising:

[0006] S100: Mn304 of component A, Co2O3 of component B, Ni0 of component C, and Fe2O3 of component D are mixed to form a preparation raw material, and the preparation raw material is ball-milled, roasted and dehydrated to obtain a dry ball-milled raw material;

[0007] S200: uniformly mixing the ball-milled raw material and the binder to obtain chip slurry;

[0008] S300: pressing the chip slurry into a thin sheet, baking the thin sheet, and then grinding both sides of the baked thin sheet to obtain a green sheet;

[0009] S400: sintering the green sheet at a temperature of 1280° C.-1300° C. to obtain a chip module.

[0010] As a preferred technical solution for the preparation method of the above-mentioned chip module, A, B, C and D satisfy: 550≤A≤570, 55≤B≤65, 690≤C≤710, 790≤D≤810, each component is a particle with a particle size not greater than 500nm, and the purity of each component is not less than 99%.

[0011] As a preferred technical solution for the preparation method of the above chip module, A=560, B=60, C=700, D=800, the average particle size range of each component is 200nm-300nm, and the purity of each component is greater than 99.5%.

[0012] As a preferred technical solution for the preparation method of the above-mentioned chip module, in S100, the raw materials are mixed evenly and poured into a ball mill and water is added for ball milling. The weight of the water is 1.08 times the weight of the raw materials. The ball milling time ranges from 30 hours to 50 hours. The ball-milled material is then calcined and dehydrated. The calcination temperature is 125°C and the calcination time ranges from 10 hours to 14 hours.

[0013] As a preferred technical solution of the preparation method of the above chip module, the ball milling time is 40 hours, and the calcination time is 12 hours.

[0014] As a preferred technical solution for the preparation method of the above chip module, in S200, the adhesive is a mixture of n-butyl phthalate and white latex, the weight of the n-butyl phthalate is 4% of the weight of the ball-milled raw material, and the weight of the white latex is 1.5% of the weight of the ball-milled raw material.

[0015] As a preferred technical solution of the method for preparing the chip module, in S300, the chip paste is pressed into a thin sheet with a thickness of 0.52 mm through multiple processing steps.

[0016] As a preferred technical solution for the preparation method of the above chip module, the multiple processing steps include first stamping, first drying, second stamping, second drying, third stamping, baking, and fourth stamping in sequence.

[0017] As a preferred technical solution for the preparation method of the above-mentioned chip module, in S300, the thin slice is baked under the control of a PID controller, and then the baked thin slice is grinded on both sides by a grinder to obtain a green sheet, and the thickness of the green sheet ranges from 0.49mm to 0.51mm.

[0018] As a preferred technical solution of the method for preparing the chip module, in S400, the green sheets are arranged in a refractory box and sintered under a PID controller to obtain the chip module, wherein the sintering temperature is 1290°C.

[0019] The beneficial effects of the present invention are:

[0020] The present invention provides a method for preparing a chip module, which comprises: first, mixing Mn304 of component A, Co2O3 of component B, Ni0 of component C, and Fe2O3 of component D, ball milling, roasting and dehydrating, and obtaining a dry ball milling raw material; secondly, uniformly mixing the ball milling raw material with an adhesive to obtain a chip slurry; pressing the chip slurry into a thin sheet; roasting the thin sheet; then polishing the thin sheet after the roasting treatment on both sides to obtain a blank sheet; and finally sintering the blank sheet at a temperature of 1280°C-1300°C to obtain a chip module. Through the synergistic compounding of the component materials, the thickness of the chip module is increased, so that it is convenient to polish it on both sides, ensure the smoothness and consistency of its surface, prevent the resistance from changing in performance during long-term operation and causing resistance drift, and make it difficult to be broken down when the current passes through repeatedly, effectively extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic flow chart of a method for preparing a chip module provided by the present invention. DETAILED DESCRIPTION

[0022] Embodiments of the present invention are described in detail below, examples of which 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 to be used to explain the present invention, and should not be construed as limiting the present invention.

[0023] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0024] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] Unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0026] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0027] like Figure 1 As shown, this embodiment provides a method for preparing a chip module, and the method for preparing the chip module includes:

[0028] S100: Mn304 of component A, Co2O3 of component B, Ni0 of component C, and Fe2O3 of component D are mixed to form a raw material, and the raw material is ball-milled, roasted and dehydrated to obtain a dry ball-milled raw material;

[0029] S200: uniformly mixing the ball milled raw material and the binder to obtain chip slurry;

[0030] S300: pressing the chip slurry into a thin sheet, baking the thin sheet, and then grinding both sides of the baked thin sheet to obtain a green sheet;

[0031] S400: sintering the green sheet at a temperature of 1280° C.-1300° C. to obtain a chip module.

[0032] Through the synergistic compounding of the above-mentioned component materials, the chip module is thicker than the chip module with the same B value, so it is convenient to polish it on both sides, ensure the smoothness and consistency of its surface, and prevent the resistance from changing in performance during long-term operation and causing resistance drift (after 5 years of use, the resistance drift does not exceed 1%, and after 10 years, the resistance drift does not exceed 3%). At the same time, due to the increase in the thickness of the prepared chip module, the chip can withstand a current of 20mA and is not easily broken down when the current passes through repeatedly, effectively extending its service life. It should be noted that the above-mentioned B value is a constant used to characterize the sensitivity of the thermistor to temperature, which is expressed by the change in zero-power resistance over time, and its expression is:

[0033]

[0034] Wherein, T1 and T2 are different arbitrary temperature values ​​(K), R1 is the zero-power resistance value (Q) at T1, and R2 is the zero-power resistance value (Q) at T2.

[0035] Optionally, A, B, C and D satisfy: 550≤A≤570, 55≤B≤65, 690≤C≤710, 790≤D≤810, each component is a particle with a particle size not greater than 500 nm, and the purity of each component is not less than 99%.

[0036] Specifically, the following schemes are exemplified in this embodiment: A=560, B=60, C=700, D=800, the average particle size range of each component is 200nm-300nm, and the purity of each component is greater than 99.5%; or, A=560, B=60, C=700, D=800, the average particle size range of each component is 200nm-300nm, and the purity of each component is greater than 99.5%; or, A=570, B=65, C=7000, D=805, the average particle size range of each component is 300nm-400nm, and the purity of each component is greater than 99.6%; or, A=570, B=55, C=710, D=810, the average particle size range of each component is 400nm-500nm, and the purity of each component is greater than 99.9%.

[0037] Optionally, in S100, the prepared raw materials are mixed evenly and poured into a ball mill and water is added for ball milling. The weight of the water is 1.08 times the weight of the prepared raw materials. The ball milling time ranges from 30 hours to 50 hours. Further, the ball milling time is 40 hours. The ball-milled material is then calcined and dehydrated. The calcination temperature is 125°C. The calcination time ranges from 10 hours to 14 hours. Further, the calcination time is 12 hours.

[0038] It should be noted that ball milling using a ball mill is a common technique in the art, which is divided into two types: dry milling and wet milling. For wet milling, a certain amount of water needs to be added. Usually, the weight of the water added is equivalent to the weight of the material to be milled. If the amount of water is too much, the crushing ability will decrease, and if the amount of water is too little, the movement of the grinding body in the ball mill will be hindered. The component materials of the chip module in the embodiment of the present invention are all nanoparticles. Due to their small particle size and large specific surface area, they absorb a large amount of water. It has been proved by experiments that adding water 1.08 times the weight of the material can achieve a better ball milling effect. The length of the ball milling time directly affects the particle size and purity of the product. In the initial stage of ball milling, the particle size decreases rapidly with the extension of time. After a certain period of ball milling, the particle size gradually reaches a stable equilibrium state, but the pollution caused by the long ball milling time affects the purity of the product. Therefore, the preferred ball milling time in the embodiment of the present invention is 40 hours.

[0039] Optionally, in S200, the adhesive is a mixture of n-butyl phthalate and white latex, the weight of n-butyl phthalate is 4% of the weight of the ball-milled raw material, and the weight of the white latex is 1.5% of the weight of the ball-milled raw material. Wherein, the main component of the white latex is polyvinyl acetate, water is used as a dispersant, and a polymer compound polymerized from polyvinyl alcohol and formaldehyde is added as a modifier to improve the water resistance and freeze-thaw resistance of the white latex. The adhesive according to this ratio has the advantages of strong bonding force, low volatility, no effect on the chemical properties of the raw materials, moderate viscosity and conducive to uniform mixing.

[0040] Optionally, in S300, the chip slurry is pressed into a sheet with a thickness of 0.52 mm through the processes of first stamping, first drying, second stamping, second drying, third stamping, baking, and fourth stamping in sequence. The specific operation steps are as follows:

[0041] S10: using a tablet press to press the chip slurry into a thin sheet with a thickness of 0.6 mm;

[0042] S20: Fix a sheet with a thickness of 0.6 mm using a clip and hang it at ambient temperature for 20 minutes to dry the sheet;

[0043] S30: Pressing the sheet with a thickness of 0.6 mm into a sheet with a thickness of 0.55 mm;

[0044] S40: Cut the slice with a thickness of 0.55 mm into strips with a width of about 44 mm, arrange the strips on a stainless steel mesh, and air-dry the front and back sides at ambient temperature for 10 minutes each;

[0045] S50: Pressing the strip with a thickness of 0.55 mm into a sheet with a thickness of 0.53 mm;

[0046] S60: Cut a thin sheet with a thickness of 0.53 mm into square thin sheets with a side length of 44 mm, arrange the square thin sheets on a stainless steel mesh, and put them into an oven for baking at 60° C. for 10 min.

[0047] S70: A square sheet with a thickness of 0.53 mm is pressed into a sheet with a thickness of 0.52 mm, and arranged on a glass plate.

[0048] S80: calcining a sheet with a thickness of 0.52 mm, and calcining at 60° C. for 12 hours under the control of a PID controller, and then calcining again after cooling to room temperature, using a PID controller to control the temperature, and calcining at 60° C. for 1 hour, 70° C. for 1 hour, 80° C. for 1 hour, 90° C. for 1 hour, 100° C. for 1 hour, 110° C. for 1 hour, and 126° C. for 6 hours;

[0049] S90: grinding both sides of the calcined slices with a grinder to obtain a green sheet with a smooth surface, which can be prepared for subsequent coating of silver paste so that the silver paste can evenly cover the surface of the green sheet. The thickness of the green sheet ranges from 0.49 mm to 0.51 mm, preferably 0.5 mm.

[0050] It should be noted that the PID controller performs deviation adjustment on the control system according to the PID control principle, so that the process variables such as temperature, pressure, flow, hydraulic pressure, etc. of the production device are maintained at a certain value to meet the requirements of the production process. The embodiment of the present invention uses the PID controller to control the temperature, and can effectively control the roasting temperature within the set temperature range, thereby achieving an ideal roasting effect.

[0051] Optionally, in S400, the green sheets are arranged in a refractory box and placed in a PID controller for sintering to obtain a chip module, wherein the sintering temperature is 1290° C. The green sheets are transformed into a dense chip module through the sintering process, making its performance in all aspects more stable.

[0052] In addition, the performance of the chip module can be tested by the following test methods:

[0053] (1) Current impact test: A direct current power-on test is performed on the chip module (reference resistance value is 0.388KΩ) provided in the embodiment of the present invention at 120°C. The DC voltage loaded on the chip module is gradually increased from 5V. During the power-on process, the resistance output of the resistor is detected. The current point at which the resistance or B value changes by more than 3% of the original value and the current point at which the chip breaks down are selected respectively.

[0054] (2) High and low temperature test: Under 5V DC voltage, the resistor is baked in a high temperature environment of 100℃±2℃ for 1000 hours to test the changes in resistance and B value.

[0055] (3) Stability test: Under a DC voltage of 5 V, a thermal shock test was performed on the chip module provided by the embodiment of the present invention using a thermal shock machine, at -40°C for 20 min, at 100°C for 20 min, with an intermediate conversion time of 2 min, for 5000 cycles.

[0056] In this embodiment, the NTC thermistor can be obtained by coating diluted silver paste on both sides of the chip module, and then drying, sintering, slicing, and welding the leads in sequence. The specific operation steps are as follows:

[0057] S1: Mix the prepared raw materials, pour them into a ball mill, add water in an amount 1.08 times the weight of the prepared raw materials into the ball mill, and ball mill for 40 hours. Then, the ball-milled materials are calcined and dehydrated at a calcination temperature of 125° C. for 12 hours to obtain dry ball-milled raw materials.

[0058] S2: Weigh 600 g of the dried ball-milled raw material, add 24 g of n-butyl phthalate and 9 g of white latex, mix well, and obtain chip slurry.

[0059] S3: The chip slurry is pressed into a thin sheet with a thickness of 0.52 mm through the processes of the first punching, the first drying, the second punching, the second drying, the third punching, the baking, and the fourth punching, and the thin sheet is baked, and then the baked thin sheet is polished on both sides to obtain a green sheet with a thickness of 0.5 mm.

[0060] S4: Arrange the green sheets in a refractory box and sinter them under a PID controller to obtain a chip module. The sintering temperature is 1290°C.

[0061] S5: Diluted silver paste is coated on both sides of the chip module, wherein the diluted silver paste is composed of silver paste and silver paste diluent. In order to obtain an NTC thermistor with excellent performance, the weight ratio of silver paste to silver paste diluent is 100:5. The chip module coated with silver paste is arranged on a stainless steel mesh, and baked at 125°C for 10min-15min until dry, then put into a refractory box, put into a sintering furnace, and sintered at 650°C using a PID controller. According to the resistance requirements, the chip is cut into small pieces of 1.32mm×1.44mm, and the leads are welded to form an NTC thermistor with a resistance of R25=10KQ±1% and a B value of B25 / 85=3435K±1%. Among them, R25 represents the zero-power resistance value of the thermistor at 25℃, and B25 / 85 represents the change in the zero-power resistance value of the thermistor over time when T1 is 25℃ and T2 is 85℃.

[0062] It should be noted that silver paste is a viscous paste composed of a mechanical mixture of high-purity (purity of 99.9%) metallic silver particles, adhesives, solvents, and additives. The silver paste used in the embodiment of the present invention is a sintered conductive silver paste, and its components are as follows: silver powder, bisphenol A epoxy resin, anhydride curing agent, and butyl acetate. The thickness of the silver paste on the surface of the chip module coated with silver paste is about 6μm. The silver paste is solidified by sintering.

[0063] Welding leads is a commonly used technical means in this field. Usually, a thermal ultrasonic bonding process is used to weld the welding wire to the welding pads on the chip and the welding pads on the lead frame or substrate, so that the welding wire forms a good ohmic contact between the chip electrode and the external lead bonding area, completing the connection of the internal and external circuits of the chip.

[0064] In addition, according to different resistance requirements, the chip can be cut into small pieces of different specifications and the leads can be welded to form NTC thermistors with different resistance values.

[0065] Furthermore, the NTC thermistor is encapsulated with epoxy resin by using epoxy resin powder to obtain an epoxy resin encapsulated NTC thermistor.

[0066] Specifically, the above-mentioned epoxy resin encapsulation can be achieved by the following steps: using a powder impregnation machine to wrap and impregnate the chip module and the lead welding points with epoxy resin powder, and baking and curing at 150°C for 2 hours to form a cured epoxy resin coating layer, thereby manufacturing an epoxy resin encapsulated NTC thermistor. The specific operation steps are as follows:

[0067] There are three powder tanks on the powder impregnation machine, and each powder tank is equipped with a heating and curing area behind it. The conveyor belt drives the NTC thermistor to operate, so that it is stained with epoxy resin powder in the powder tank, and cured in the high-temperature curing area to achieve epoxy resin impregnation, and then impregnated in the second powder box and curing area, and the third powder box and curing area in turn. After impregnation, the powder impregnation machine automatically rolls the NTC thermistor onto a disk, and bakes and cures it in an oven at 150°C for 2 hours to form a cured epoxy resin coating, thereby making an epoxy resin encapsulated NTC thermistor. The epoxy resin encapsulated NTC thermistor has a longer service life because its chip is protected.

[0068] The performance of the prepared NTC thermistor was tested, and the results are as follows:

[0069] (1) The NTC thermistor prepared by using raw materials with A=560, B=60, C=700, D=800, the average particle size range of each component is 200nm-300nm, and the purity of each component is greater than 99.5% can withstand 18mA current shock; can withstand 4900 high and low temperature shocks, and the resistance deviation is less than 3%; after 5 years of use, the resistance drift does not exceed 1%. After 10 years of use, the resistance drift does not exceed 3%.

[0070] (2) The NTC thermistor prepared by using raw materials with A=560, B=60, C=700, D=800, an average particle size range of each component of 200nm-300nm, and a purity of each component greater than 99.5% can withstand 19mA current shock; can withstand 4900 high and low temperature shocks, and the resistance deviation is less than 3%; after 5 years of use, the resistance drift does not exceed 1%, and after 10 years of use, the resistance drift does not exceed 3%.

[0071] (3) The NTC thermistor prepared by using raw materials with A=570, B=55, C=710, D=810, the average particle size range of each component is 400nm-500nm, and the purity of each component is greater than 99.9% can withstand 20mA current shock; can withstand 5000 high and low temperature shocks, and the resistance deviation is less than 3%; after 5 years of use, the resistance drift does not exceed 1%, and after 10 years of use, the resistance drift does not exceed 3%.

[0072] (4) The NTC thermistor prepared by using raw materials with A=570, B=65, C=7000, D=805, the average particle size range of each component is 300nm-400nm, and the purity of each component is greater than 99.6% can withstand 19mA current shock; can withstand 4950 high and low temperature shocks, and the resistance deviation is less than 3%; after 5 years of use, the resistance drift does not exceed 1%, and after 10 years of use, the resistance drift does not exceed 3%.

[0073] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a chip module, characterized in that: include: S100: Mn304 of component A, Co2O3 of component B, Ni0 of component C, and Fe2O3 of component D are mixed to form a preparation raw material, and the preparation raw material is ball-milled, roasted and dehydrated to obtain a dry ball-milled raw material; S200: uniformly mixing the ball-milled raw material and the binder to obtain chip slurry; S300: pressing the chip slurry into a thin sheet, baking the thin sheet, and then grinding both sides of the baked thin sheet to obtain a green sheet; S400: sintering the green sheet at a temperature of 1280° C.-1300° C. to obtain a chip module.

2. The method for preparing a chip module according to claim 1, characterized in that: A, B, C and D satisfy: 550≤A≤570, 55≤B≤65, 690≤C≤710, 790≤D≤810, each component is a particle with a particle size not greater than 500nm, and the purity of each component is not less than 99%.

3. The method for preparing a chip module according to claim 2, characterized in that: A=560, B=60, C=700, D=800, the average particle size of each component ranges from 200nm to 300nm, and the purity of each component is greater than 99.5%.

4. The method for preparing a chip module according to claim 1, characterized in that: In S100, the prepared raw materials are mixed evenly and poured into a ball mill and water is added for ball milling. The weight of the water is 1.08 times the weight of the prepared raw materials. The ball milling time ranges from 30 hours to 50 hours. The ball-milled materials are then calcined and dehydrated. The calcination temperature is 125° C. and the calcination time ranges from 10 hours to 14 hours.

5. The method for preparing a chip module according to claim 4, characterized in that: The ball milling time is 40 hours, and the calcination time is 12 hours.

6. The method for preparing a chip module according to claim 1, characterized in that: In S200, the binder is a mixture of n-butyl phthalate and white latex, the weight of the n-butyl phthalate is 4% of the weight of the ball-milled raw material, and the weight of the white latex is 1.5% of the weight of the ball-milled raw material.

7. The method for preparing a chip module according to claim 1, characterized in that: In S300, the chip paste is pressed into a sheet with a thickness of 0.52 mm through multiple processing steps.

8. The method for preparing a chip module according to claim 7, characterized in that: The multiple processing steps include first punching, first drying, second punching, second drying, third punching, roasting, and fourth punching in sequence.

9. The method for preparing a chip module according to claim 7, characterized in that: In S300, the thin slice is calcined under the control of a PID controller, and then the calcined thin slice is polished on both sides by a polisher to obtain a green sheet, and the thickness of the green sheet is in the range of 0.49 mm to 0.51 mm.

10. The method for preparing a chip module according to claim 1, characterized in that: In S400, the green sheets are arranged in a refractory box and placed in a PID controller for sintering to obtain the chip module, wherein the sintering temperature is 1290°C.

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