PCB winding transformer boost power supply integrally formed by metal powder die casting

Abstract

The invention relates to a PCB winding transformer boosting power source integrally formed through metal powder die casting, and belongs to the field of power source design. The boost power supply comprises an intelligent power switch device IMP650A, a transformer winding manufactured by a multi-layer PCB (Printed Circuit Board), and a metal powder core which is die-cast outside the transformer winding and is sintered at a low temperature. The size of the boost power supply can be reduced, the switching efficiency is improved, and the optimal boost rate is obtained; the temperature rise of the boost power supply is only 6-8 DEG C under the condition of maintaining the high voltage of 2000V, so that the reliability is effectively ensured; the windings are manufactured by adopting a PCB (Printed Circuit Board), the process is mature and stable, the insulation between the windings is good, the sparking and discharging phenomena are avoided under the highest 2000V output condition, and the reliability is ensured; the integrated die-cast iron-silicon-aluminum powder core is adopted, the magnetic flux density is 4-5 times that of a traditional product, the power density is higher, magnetic core saturation does not need to be worried about, and the reliability requirement in the high-temperature environment can be met.

Description

Technical Field

[0001] The invention belongs to the field of power supply design, and in particular relates to a PCB winding transformer boost power supply which is integrally formed by metal powder die-casting. Background Art

[0002] The high-efficiency high-voltage boost power supply for the Dungan gunpowder fuze is a fast and efficient ignition energy source for missiles and rockets. Its function is to quickly boost the 20-30V low-voltage power supply to 1000-2000V and store it in a high-voltage capacitor to provide it for fuze ignition. The requirements for this power supply include:

[0003] First, the input power supply voltage range is wide: 20-30V, which can be further expanded to 18-32V;

[0004] Second, the volume should be as small as possible, no more than 1mL, the smaller the better;

[0005] Third, the boost efficiency is high to prevent the temperature rise in a small volume from being too high, and the temperature rise should not be greater than 10°C;

[0006] Fourth, the voltage boost speed is fast. At a 24V input voltage, the time to boost to 2000V when the energy storage capacitor is 0.22uF is less than 100mS, which is equivalent to a maximum power of 40W. Calculated based on a volume of 0.8mL, the volume power density reaches 50W / mL.

[0007] At present, there are still the following problems in the domestic high-voltage power supply of fuze:

[0008] First, the frequency of the boost switch is restricted. Traditional silicon-based MOS tubes have large input capacitance and the switching frequency is difficult to exceed 100Khz, thus limiting the volume power density of the switching power supply. In order to meet the design requirements, the method involved in the present invention is to use a switch tube with better frequency characteristics, such as a gallium nitride MOS tube, and in order to further reduce the volume, it is necessary to integrate the intelligent switch control component with the gallium nitride MOS tube.

[0009] Second, the ferrite core used to manufacture the switching transformer is limited by the flux density and temperature characteristics. The traditional ferrite core has a very small flux density of only 300-400mT. Such a small flux density means that more turns of wire are needed under the same magnetic column area. According to the law of electromagnetic induction, U=N*dΦ / dt, Φ is the magnetic flux, Φ=B*S, B is the magnetic flux density, and S is the cross-sectional area of ​​the magnetic column. Therefore, the smaller flux density of ferrite material means more turns, which is very unfavorable for reducing the size of the power supply. At the same time, ferrite materials are greatly affected by temperature, and the magnetic flux density decreases rapidly with the increase of temperature. Therefore, once the temperature rise of the switching transformer using ferrite as the core exceeds the critical value, the coil inductance will drop rapidly, resulting in a sharp increase in current, and the sharp increase in current will further cause the core temperature to rise, exacerbating the burning of the transformer. This is the insecurity of ferrite materials.

[0010] The solution of the present invention is to use a metal powder core with a higher magnetic flux density to manufacture the magnetic core of the switching transformer. The present invention uses sendust aluminum alloy powder, which has a magnetic flux density 4-5 times that of ferrite and better thermal stability.

[0011] Third, winding transformer coils is very difficult. High insulation is required under high voltage conditions, and winding transformer coils in a small size has become the biggest difficulty at present.

[0012] The method involved in the present invention is to use a multi-layer PCB to realize the winding of the transformer through routing. Summary of the invention

[0013] 1. Technical issues to be resolved

[0014] The technical problem to be solved by the present invention is how to provide a PCB winding transformer boost power supply which is integrally formed by metal powder die-casting to solve the above-mentioned problem of a high-efficiency boost power supply dedicated to a fuze.

[0015] (II) Technical solution

[0016] In order to solve the above technical problems, the present invention proposes a PCB winding transformer boost power supply formed by metal powder die-casting, the boost power supply comprising: an intelligent power switch device IMP650A, a transformer winding made of a multi-layer PCB, and a metal powder core die-cast outside the transformer winding and sintered at a low temperature;

[0017] The intelligent power switch device IMP650A includes: an intelligent switch controller U1 and a GaN field effect transistor U2; the intelligent switch controller U1 internally includes a controller for changing the switch cycle according to an exponential law and a voltage feedback controller; the GaN field effect transistor U2 is used to amplify the pulse drive signal generated by the intelligent switch controller U1 to obtain a second impulse power signal as the output of the intelligent power switch device IMP650A;

[0018] The transformer winding made of multi-layer PCB includes: N layers of stacked PCB boards, and protective films on the upper and lower surfaces of each layer of PCB boards; the transformer winding is divided into two windings, namely, a primary winding and a secondary winding, the primary winding occupies the outermost PCB board, i.e., the upper and lower layers, and the secondary winding occupies the inner PCB board; the input end of the primary winding is connected to the output of the intelligent power switch device IMP650A, and the output end of the secondary winding is used as the output of the entire boost power supply; the transformer winding has a circular magnetic column hole in the middle, and magnetic core side column gaps are left on four sides;

[0019] The metal powder core is die-cast outside the transformer winding and sintered at low temperature. It is made of magnetic core powder obtained by die-casting and sintering by mixing metal powder and epoxy resin. After the two materials are evenly mixed, a die is used to achieve die-casting through a double-sided filling method. During die-casting, the transformer winding made of multi-layer PCB is in the middle, and the magnetic core powder will fill the middle magnetic column hole and the core side column gap to form a closed magnetic core loop, so that the magnetic core wraps the transformer winding for shielding.

[0020] (III) Beneficial effects

[0021] The present invention provides a PCB winding transformer boost power supply formed by metal powder die-casting. The beneficial effects of the present invention include:

[0022] 1. The most reasonable boost control

[0023] Through calculation and analysis, it is found that the boosting process of the fuse boost power supply is a process of variable period and variable power, and the optimal switching period variation law is to gradually decrease from the maximum initial value according to the e exponential function. The present invention designs an intelligent switching device IMP650A, which encapsulates a gallium nitride field effect tube die and an intelligent controller. The intelligent controller provides functions such as algorithms, hardware components, parameter settings, etc. for the switching period to change according to the exponential law, and provides a voltage stability feedback condition algorithm.

[0024] By using the IMP650A device involved in the present invention, the volume of the boost power supply can be greatly reduced, while the switching efficiency can be improved and the optimal boost rate can be obtained.

[0025] 2. Small-volume, reproducible switching transformers

[0026] The switch transformer involved in the present invention consists of two parts: a transformer winding made of a multi-layer PCB and a magnetic core die-casted outside the PCB winding by using metal powder and epoxy resin.

[0027] The present invention realizes an integrated switch transformer with high efficiency, high frequency operation and high power density. The indicators achieved are: the switching frequency reaches above 200Khz, the power density is as high as: 100W / mL, and the size is reduced to: 11*12*7mm.

[0028] 3. The present invention relates to a boost power supply for fuze, the reliability of which is greatly improved due to the adoption of the following technical measures:

[0029] First, IMP650A integrates a 650V, 10A GaN field effect tube. The GaN field effect tube has good high-frequency characteristics. At a switching frequency of up to 200Khz, the switching efficiency exceeds 96% and almost no heat is generated. The boost power supply manufactured by the present invention has a temperature rise of only 6-8°C while maintaining a high voltage of 2000V, and the reliability is effectively guaranteed.

[0030] Second, the windings are manufactured using PCB, which has a mature and stable process, good insulation between windings, and no sparking or discharge under the maximum 2000V output condition, so reliability is guaranteed.

[0031] Third, the integrated die-casting iron silicon aluminum powder core has a magnetic flux density that is 4-5 times that of traditional products, a higher power density, and no need to worry about core saturation, which can meet the reliability requirements in high temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a structural diagram of the intelligent power device IPM650A of the present invention;

[0033] Figure 2 It is a schematic diagram of the PCB transformer winding of the present invention;

[0034] Figure 3 It is the diagram of the switching cycle variation;

[0035] Figure 4 This is the diagram of the switching power variation. DETAILED DESCRIPTION

[0036] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples.

[0037] In order to solve the above-mentioned problems of the high-efficiency dedicated boost power supply for fuses, the present invention carries out innovative design from three aspects: first, the intelligent power switch device IMP650A; second, the transformer winding manufactured by multi-layer PCB; third, the metal powder core that is die-cast outside the transformer winding and sintered at low temperature.

[0038] The present invention provides a PCB winding transformer boost power supply formed in one piece by metal powder die-casting, comprising: an intelligent power switch device IMP650A, a transformer winding made of a multi-layer PCB, and a metal powder core die-casted outside the transformer winding and sintered at a low temperature;

[0039] The intelligent power switch device IMP650A includes: an intelligent switch controller U1 and a GaN field effect transistor U2; the intelligent switch controller U1 internally includes a controller for changing the switch cycle according to an exponential law and a voltage feedback controller; the GaN field effect transistor U2 is used to amplify the pulse drive signal generated by the intelligent switch controller U1 to obtain a second impulse power signal as the output of the intelligent power switch device IMP650A;

[0040] The transformer winding made of multi-layer PCB includes: N layers of stacked PCB boards, and protective films on the upper and lower surfaces of each layer of PCB boards; the transformer winding is divided into two windings, namely, a primary winding and a secondary winding, the primary winding occupies the outermost PCB board, i.e., the upper and lower layers, and the secondary winding occupies the inner PCB board; the input end of the primary winding is connected to the output of the intelligent power switch device IMP650A, and the output end of the secondary winding is used as the output of the entire boost power supply; the transformer winding has a circular magnetic column hole in the middle, and magnetic core side column gaps are left on four sides;

[0041] The metal powder core is die-cast outside the transformer winding and sintered at low temperature. It is made by die-casting and sintering a mixture of metal powder and epoxy resin. After the two materials are evenly mixed, a die is used to die-cast by double-sided filling. During die-casting, the transformer winding made of multi-layer PCB is in the middle.

[0042] Embodiment 1:

[0043] (1) Intelligent power switch device IMP650A

[0044] Different from the traditional switching power supply, the load of the fuze-specific boost power supply is a high-voltage capacitor, which requires the voltage of the high-voltage capacitor to be boosted from 0V to 1000-2000V in the shortest possible time. For the convenience of description, 2000V is used as an example below.

[0045] Based on the mathematical relationship of capacitor boost, we can draw a conclusion: this boost process is a process of switching cycle change and dynamic power change.

[0046] The optimal boost switching cycle variation law is obtained through precise mathematical calculations. This is a law that changes according to the exp exponential function. Only by changing the switching cycle according to this law can the optimal boost curve be obtained.

[0047] The traditional switching power supply control is a fixed-cycle switching control, so it cannot meet the requirements of the fuse power supply. To solve this problem, the present invention designs a special intelligent component. This intelligent component is based on a high-reliability CPU and contains a high-reliability exponential switching cycle change switch controller and a voltage feedback stabilization algorithm.

[0048] At the same time, in order to improve the operating frequency and efficiency of the power switch tube, the present invention selects a 650V, 10A GaN field effect tube core and a dedicated intelligent switch controller to seal it together to manufacture an intelligent power device: IPM650A.

[0049] The internal structure of IPM650A is as follows Figure 1 As shown, it includes: intelligent switch controller U1 and GaN field effect transistor U2, GaN field effect transistor is referred to as switch tube, and intelligent switch controller is referred to as intelligent controller. The device contains a highly reliable controller that changes the switch cycle according to the exponential law, a voltage feedback controller, etc. Figure 1 shown.

[0050] The present invention relates to an intelligent power switch device IMP650A, which is composed of two parts. The first part is a gallium nitride field effect tube U2; the second part is an intelligent switch controller U1. The internal parts are connected by wire bonding and then connected to the chip pins to be packaged into a QFN or DFN device;

[0051] The intelligent switch controller U1 contains a highly reliable switch controller that changes the switch cycle according to the exponential law. The switch cycle of this switch control starts from the maximum value and then gradually decreases according to the exponential law of e. By setting the starting maximum switch cycle and the time constant of the exponential function of e, the boost speed can be changed. The GaN field effect transistor U2 is used to amplify the pulse drive signal generated by the intelligent switch controller U1 to obtain a second impulse power signal as the output of the intelligent power switch device IMP650A.

[0052] The intelligent switch controller U1 contains an output voltage feedback stabilization algorithm. After the boost is completed, it can determine whether to replenish energy to the energy storage capacitor by measuring the change in the output voltage, thereby stabilizing the output voltage within a set range.

[0053] (2) Transformer windings made of multi-layer PCB

[0054] The present invention relates to a method for manufacturing transformer windings using a multi-layer PCB board, such as Figure 2 shown.

[0055] The transformer winding manufactured by the multi-layer PCB involved in the present invention is preferably manufactured by using an 8-layer PCB board, and of course, it can also be manufactured by using a 10-layer or other level PCB process.

[0056] The PCB transformer windings involved in the present invention are composed of two windings, namely, a primary winding and a secondary winding, wherein the primary winding occupies the outermost PCB board, i.e., the upper and lower layers, and the secondary winding occupies the inner PCB board, which is a preferred design. The advantages of this are that the primary winding voltage is low, the secondary voltage is high, and being made in the inner layer is conducive to insulation. The input end of the primary winding is connected to the output of the intelligent power switch device IMP650A, and the output end of the secondary winding is used as the output of the entire boost power supply.

[0057] The PCB transformer involved in the present invention has two windings, primary and secondary, with 6 turns in the primary winding and 32 turns in the secondary winding, and a step-up ratio of 1:5.33, which is a preferred design, and other turns or turns ratios can also be used. The preferred solution is the result obtained through repeated tests, and the effect is better.

[0058] The PCB transformer winding of the present invention has a layer of polyimide film thermally pressed on the upper and lower surfaces of the PCB board as a protective film to play an insulating and protective role.

[0059] The PCB transformer winding of the present invention is provided with transformer pin welding holes at four corners, and the pins can be welded as winding lead pins.

[0060] The transformer winding manufactured by the multi-layer PCB of the present invention has a circular magnetic column hole in the middle and magnetic core side column gaps on the four sides. Figure 2 shown.

[0061] Among them, the transformer winding manufactured by the multi-layer PCB involved in the present invention has a PCB board thickness of preferably 1.6mm, and the thickness of the two layers of polyimide protective films pressed externally by heating are 0.02-0.03mm respectively, and the total thickness is about 1.65mm, which is the preferred value. Of course, other thicknesses can also be used.

[0062] Among them, the transformer winding manufactured by the multi-layer PCB involved in the present invention is preferably manufactured using an 8-layer board, containing two windings, primary and secondary. The preferred winding arrangement order is: the outermost layer is the primary, and the inner 6 layers are the secondary, which is convenient for insulation treatment.

[0063] Among them, the transformer winding manufactured by the multi-layer PCB involved in the present invention has a layer of polyimide protective film hot-pressed on the upper and lower surfaces, which is a preferred solution. A vapor-deposited parylene film can also be used as protection, but polyimide has lower cost and better effect. Therefore, as a preferred solution, a printed protective film can also be used, or a protective film of other materials can be used. However, the effect is not as good as the preferred solution and cannot be used as a reason for circumventing the present invention.

[0064] Among them, the transformer winding manufactured by the multi-layer PCB involved in the present invention has a middle magnetic column hole in the middle of the PCB and magnetic core side column gaps on the four sides. During die-casting, the magnetic core powder will fill the middle magnetic column hole and the magnetic core side column gaps to form a closed magnetic core loop, so that the magnetic core can wrap the transformer winding coil to obtain a better shielding effect.

[0065] (3) Metal powder core die-cast outside the transformer winding and sintered at low temperature

[0066] The present invention relates to a small-volume, high-efficiency switching transformer, which is composed of a winding (made of PCB) and a metal powder core wrapped outside the winding. The present invention uses a metal powder core with a higher magnetic flux density to manufacture the magnetic core of the switching transformer. The present invention preferably uses an iron-silicon-aluminum alloy powder, which has a magnetic flux density 4-5 times that of ferrite and better thermal stability. Other soft magnetic powder materials such as pure iron, silicon steel, permalloy, ferrite, etc. can also be used, but the price or performance is not as good as the preferred solution. Changing the powder material cannot be used as an excuse to circumvent the present invention.

[0067] The preferred material for the metal powder core is sendust powder, with a particle diameter range of 3-10μm and a best range of 5-6μm. Too fine iron powder will result in a high proportion of passivation film and insufficient magnetic permeability. The surface of sendust powder is phosphated and passivated to play an insulating role and prevent excessive iron loss in the iron core.

[0068] The metal powder core is made of a mixture of iron silicon aluminum powder and medium temperature curing two-component epoxy resin. The epoxy resin mass accounts for 2-3%. After the two materials are mixed evenly, a die is used to achieve die casting through the double-sided filler method. During die casting, the transformer winding made of multi-layer PCB is in the middle. The die casting pressure is 50-100Mp, and the static pressure time is 1-2 hours to fully remove the air in the magnetic core. During die casting, the transformer pin welding holes are not die-cast and need to be protected. The die-cast semi-finished product is placed in a constant temperature box at a temperature of 90-120℃ and sintered and cured for 24 hours to allow the two-component epoxy resin to fully react and provide sufficient bonding strength.

[0069] Among them, the present invention relates to a small-volume and high-efficiency switching transformer, the winding of which is manufactured by multi-layer PCB, and the metal powder core is formed by die-casting and sintering a magnetic core powder obtained by mixing metal powder and epoxy resin. After the two materials are evenly mixed, a die is used to realize die-casting by a double-sided filling method. During die-casting, the transformer winding manufactured by multi-layer PCB is in the middle, and the magnetic core powder will fill the middle magnetic column hole and the magnetic core side column gap to form a closed magnetic core loop, so that the magnetic core wraps the transformer winding for shielding.

[0070] Among them, the iron powder core involved in the present invention adopts phosphating passivated sendust powder with a preferred diameter of 5-6μm as the main material, and other soft magnetic metal powders, such as pure iron and permalloy powder, can also be used, but they are not as cheap as sendust powder and can be used as an alternative. After being mixed with a medium-temperature curing two-component epoxy resin with a mass percentage of 2-3% as an adhesive, it is die-casted to the outside of the PCB winding using a mold. The die-casting uses a pressure of 50-100Mp, the static pressure is maintained for 1-2 hours, and the exhaust is sufficient, and then sintered in a constant temperature box at 90-120°C for 24 hours.

[0071] Working principle of the present invention

[0072] 1. Switching cycle variation law and fastest boost algorithm

[0073] The invention relates to a boost power supply dedicated to fuze, which comprises three important components: an intelligent power switch device IMP650A, a transformer winding made of multi-layer PCB, and a metal powder core which is die-casted outside the PCB transformer winding and sintered at low temperature.

[0074] The intelligent switching device IMP650A encapsulates a GaN field-effect transistor die and an intelligent controller. The intelligent controller provides functions such as algorithms, hardware components, parameter settings, etc. for exponential changes in switching cycles, and provides a voltage stability feedback condition algorithm.

[0075] The variable cycle switching algorithm of IMP650A can quickly increase the voltage to meet the real-time requirements of the weapon system. The switching cycle variation law is: T = A*exp(-t / τ), and the function curve is as follows: Figure 3 , 4 As shown: Only by following the switching cycle changes in the above figure can the boost speed of the fuze boost power supply be minimized.

[0076] 2. High-frequency working principle of GaN FET

[0077] Gallium nitride is a third-generation semiconductor with a valence band width of 3.4eV, 2.8 times that of silicon, and an electron mobility of 1500cm2 / vs, 1.25 times that of silicon. Field effect transistors made of gallium nitride have a shorter channel length and better conductivity while maintaining the same withstand voltage, which is more than three times that of silicon. Therefore, gallium nitride field effect transistors have better high-frequency performance.

[0078] The present invention utilizes the high frequency characteristics of the GaN field effect tube, and the field effect tube parameters of IMP650A are as follows:

[0079] Ciss=65P,Crss=12P,Coss=22P,on resistance is only 240mΩ at 5Vgs

[0080] Under 200 ohm driving resistance, the driving characteristic frequency = 77Mhz, while the switching frequency used in the present invention is only 0.2Mhz

[0081] At 5A current, 1:1 duty cycle, switching loss = 0.24*5*5*0.5*0.5 = 1.5W.

[0082] At 5A, duty cycle 1:1, and 24V power supply, the switching power supply output power Po = 5*24*0.5*0.5 = 30W, and the switching efficiency = (30-1.5) / 30 = 95%. Therefore, the use of GaN field-effect transistors has a very high switching efficiency.

[0083] 3. Working principle of Sendust core

[0084] The saturation magnetic induction intensity of Sendust is Bs=1.6T, while that of N95 ferrite material is Bs=0.35T. Sendust is 4.57 times that of ferrite material.

[0085] The transformer core center column is calculated as 3.5mm in diameter, the core working flux density is calculated as 1.2T, the center column flux = 11.54uWb, the opening time = 2uS, the primary is calculated as 6 turns, and the transformer primary maximum input power Um = 6*11.54 / 2 = 34.62V. If ferrite material is used, it can only withstand 8V voltage. In order to improve the withstand voltage, the number of turns can only be increased, and 24 turns are required. The transformer is composed of the primary and secondary. The increase of the primary turns by 3 times means that the secondary turns must also be increased by 3 times. If the same turns ratio of 5.33 is maintained, the secondary turns are: 128 turns, which is very difficult in a small transformer, and it is even more impossible to use PCB to manufacture the winding.

[0086] The above calculations show that the use of Sendust is a reasonable design, which can significantly reduce the number of coil turns in principle, which is a prerequisite for further use of PCB to manufacture transformer windings.

[0087] The beneficial effects of the present invention and similar comparisons:

[0088] 1. The most reasonable boost control

[0089] Through calculation and analysis, the boosting process of the fuse boost power supply is a process of variable period and variable power. The optimal switching period change law is to gradually decrease from the maximum initial value according to the e exponential function, which can be written as the following function:

[0090] T = A*exp(-t / τ)

[0091] Among them, A and τ can be reset according to parameters such as input power supply voltage and boost energy storage capacitor.

[0092] The present invention designs an intelligent switching device IMP650A, which encapsulates a gallium nitride field effect tube die and an intelligent controller. The intelligent controller provides functions such as an algorithm for exponentially changing the switching cycle, hardware components, parameter settings, and a voltage stability feedback condition algorithm.

[0093] By using the IMP650A device involved in the present invention, the volume of the boost power supply can be greatly reduced, while the switching efficiency can be improved and the optimal boost rate can be obtained.

[0094] As for the traditional solution, first, it is impossible to obtain a higher switching frequency and the power supply is limited. Second, the boost rate is unreasonable, resulting in a long boost time and unable to meet the real-time requirements of the weapon system.

[0095] 2. Small-volume, reproducible switching transformers

[0096] The switch transformer involved in the present invention consists of two parts: a winding made of a multi-layer PCB and a magnetic core die-casted outside the PCB winding by using metal powder and epoxy resin.

[0097] The present invention realizes an integrated switch transformer with high efficiency, high frequency operation and high power density. The indicators achieved are: the switching frequency reaches above 200Khz, the power density is as high as: 100W / mL, and the size is reduced to: 11X12X7mm.

[0098] Similar products can only use a maximum frequency of 80Khz, a power density of no more than 30W / mL, and a size far exceeding that of the present invention.

[0099] 3. The present invention relates to a boost power supply for fuzes. Of course, the present invention can also be used for civilian power supplies, and the advantages of small size and high efficiency are also obtained. The boost power supply has greatly improved reliability due to the following technical measures:

[0100] First, IMP650A integrates a 650V10A GaN field effect tube, which has good high-frequency characteristics. At a switching frequency of up to 200Khz, the switching efficiency exceeds 96%, and almost no heat is generated. The boost power supply manufactured by the present invention has a temperature rise of only 6-8°C while maintaining a high voltage of 2000V, and the reliability is effectively guaranteed.

[0101] Second, the windings are manufactured using PCB, which has a mature and stable process, good insulation between windings, and no sparking or discharge under the maximum 2000V output condition, so reliability is guaranteed.

[0102] Third, the integrated die-casting iron silicon aluminum powder core has a magnetic flux density that is 4-5 times that of traditional products, a higher power density, and no need to worry about core saturation, which can meet the reliability requirements in high temperature environments.

[0103] Similar products use ordinary silicon-based switching tubes and universal switching cycle control, which results in low boost efficiency and low boost rate.

[0104] Similar products use ferrite cores, which have low magnetic flux density, are easily saturated, and have poor reliability at high temperatures.

[0105] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A PCB winding transformer step-up power supply formed by metal powder die-casting, characterized in that: The boost power supply comprises: an intelligent power switch device IMP650A, a transformer winding made of a multi-layer PCB, and a metal powder core die-casted outside the transformer winding and sintered at a low temperature; The intelligent power switch device IMP650A includes: an intelligent switch controller U1 and a GaN field effect transistor U2; the intelligent switch controller U1 internally includes a controller for changing the switch cycle according to an exponential law and a voltage feedback controller; the GaN field effect transistor U2 is used to amplify the pulse drive signal generated by the intelligent switch controller U1 to obtain a second impulse power signal as the output of the intelligent power switch device IMP650A; The transformer winding made of multi-layer PCB includes: N layers of stacked PCB boards, and protective films on the upper and lower surfaces of each layer of PCB boards; the transformer winding is divided into two windings, namely, a primary winding and a secondary winding, the primary winding occupies the outermost PCB board, i.e., the upper and lower layers, and the secondary winding occupies the inner PCB board; the input end of the primary winding is connected to the output of the intelligent power switch device IMP650A, and the output end of the secondary winding is used as the output of the entire boost power supply; the transformer winding has a circular magnetic column hole in the middle, and magnetic core side column gaps are left on four sides; The metal powder core is die-cast outside the transformer winding and sintered at low temperature. It is made of magnetic core powder obtained by die-casting and sintering by mixing metal powder and epoxy resin. After the two materials are evenly mixed, a die is used to achieve die-casting through a double-sided filling method. During die-casting, the transformer winding made of multi-layer PCB is in the middle, and the magnetic core powder will fill the middle magnetic column hole and the core side column gap to form a closed magnetic core loop, so that the magnetic core wraps the transformer winding for shielding.

2. The PCB winding transformer step-up power supply integrally formed by metal powder die-casting as claimed in claim 1, characterized in that: The intelligent switch controller U1 contains a highly reliable switch controller that changes the switch cycle according to the exponential law. The switch cycle of this switch control starts from the maximum value and then gradually decreases according to the e exponential law. The boost speed is changed by setting the starting maximum switch cycle and the time constant of the e exponential function.

3. The PCB winding transformer step-up power supply integrally formed by metal powder die-casting as claimed in claim 1, characterized in that: The intelligent switch controller U1 contains an output voltage feedback stabilization algorithm. After the boost is completed, it determines whether to replenish energy to the energy storage capacitor by measuring the change in the output voltage, thereby stabilizing the output voltage within a set range.

4. The PCB winding transformer step-up power supply integrally formed by metal powder die-casting as claimed in claim 1, characterized in that: N=8 or 10.

5. The PCB winding transformer step-up power supply integrally formed by metal powder die-casting as claimed in claim 4, characterized in that: The primary winding has 6 turns, the secondary winding has 32 turns, and the step-up ratio is 1:5.

33.

6. The PCB winding transformer step-up power supply integrally formed by metal powder die-casting as claimed in claim 4, characterized in that: A layer of polyimide film or evaporated parylene film is heat-pressed on the upper and lower surfaces of the PCB as a protective film to play an insulating and protective role.

7. The PCB winding transformer step-up power supply integrally formed by metal powder die-casting as claimed in claim 4, characterized in that: Transformer pin welding holes are made on the four corners of the PCB transformer winding, which are used for welding pins as winding lead-out pins.

8. The PCB winding transformer step-up power supply integrally formed by metal powder die-casting as claimed in claim 4, characterized in that: The thickness of the PCB board is 1.6mm, and the thickness of the two layers of polyimide protective film pressed externally by heating is 0.02-0.03mm respectively, with a total thickness of about 1.65mm.

9. The PCB winding transformer step-up power supply integrally formed by metal powder die-casting as claimed in claim 1, characterized in that: The metal powder core is made of a mixture of iron silicon aluminum powder and medium temperature curing two-component epoxy resin, with the epoxy resin accounting for 2-3% by mass. After the two materials are evenly mixed, a die is used to achieve die casting through a double-sided filler method. During die casting, the transformer winding made of multi-layer PCB is in the middle, the die casting pressure is 50-100Mp, and the static pressure time is 1-2 hours to fully remove the air in the magnetic core; the die-cast semi-finished product is placed in a constant temperature box at a temperature of 90-120℃, sintered and cured for 24 hours, so that the two-component epoxy resin fully reacts.

10. The PCB winding transformer step-up power supply integrally formed by metal powder die-casting as claimed in claim 9, characterized in that: The diameter range of the Sendust powder particles is 3-10μm. The surface of the Sendust powder is phosphating passivated to play an insulating role and prevent excessive iron loss in the iron core.

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