A sensor magnetic insulation package, jig, soft magnetic receiver and assembly process

Abstract

The application relates to the field of sensor processing, in particular to a sensor magnetic insulation packaging, a magnetic jig, a soft magnetic receiver and a assembling process, the temperature sensor in the application adopts ceramic magnetic insulation packaging, is formed through high-temperature sintering, the performance of the ceramic magnet is obtained, the mechanical strength and the good insulation strength of the original ceramic are kept, and the production requirement is achieved; the magnetic field is used as a micro driving force and applied to full-automatic production of precise and small electronic original devices, a soft magnetic receiver is additionally arranged on a mechanical arm, magnetic field forces among the jig, the magnetic insulation packaging and the soft magnetic receiver are matched, automatic correction guiding, automatic clamping, automatic material placing, automatic packaging and automatic positioning are achieved, quality defects caused by uncontrollable factors in traditional sensor production processes are reduced, production procedures are simplified, and automatic assembling of the magnetic insulation packaging and sensor shell glue filling is realized.

Description

Technical Field

[0001] This invention relates to the field of sensor manufacturing, and more particularly to a magnetic insulating package for a sensor, a magnetic fixture, a soft magnetic receiver, and an assembly process for the sensor. Background Technology

[0002] A temperature sensor is an electronic device used to measure the temperature of an environment or object. It converts temperature signals into electrical signals (such as voltage, resistance, or digital signals) for monitoring, control, or recording. Commercially available temperature sensors typically employ a process of internal encapsulation followed by potting in a housing. However, the traditional internal insulating encapsulation process, involving encapsulation followed by oven curing, cannot meet the demands of fully automated production lines. Furthermore, the unpredictable size of the insulating encapsulation in existing sensor encapsulation processes significantly complicates automated production. Additionally, the flexibility of sensor wiring harnesses and the fragility of the thermistor glass body further increase the difficulty of the potting process. Conventional robotic arms and robotic hands cannot perform the precise automated assembly of the small housing and encapsulating insulator, thus failing to meet the demands of modern automated production lines. Summary of the Invention

[0003] To address the aforementioned problems, the purpose of this invention is to provide a magnetic insulating encapsulation for a sensor, a magnetic fixture, and an assembly process for the sensor. The invention employs the following technical solution:

[0004] The present invention provides a magnetically insulating package for a sensor, comprising a ceramic body, wherein the upper end of the ceramic body is a wire hole and the lower end is a device cavity communicating with the wire hole, and magnetic powder sintering cavities are provided on both sides of the ceramic body, wherein the magnetic powder sintering cavities are provided with a mixture of Fe3O4 and Al2O3 powder;

[0005] Specific implementation: First, Al2O3 is injected into the mold to form a ceramic blank. Using the mold as a support point, a second in-mold injection is performed from above the mold, or a mixture of Fe3O4 and Al2O3 powders in a 2:1 ratio is injected into the magnetic powder sintering cavity to form a complete blank. Second, the blank is sintered at 1300 degrees Celsius using the chemical reaction: Fe3O4 + 2Al2O3 → 3FeAl2O4 + O2 (↑), which solidifies the internal iron spike crystals. Then, the temperature is raised to 1600 degrees Celsius to sinter the outer ceramic body, resulting in a magnetically insulating encapsulated body with an outer Al2O3 composition and an inner FeAl2O4 composition, giving the ceramic body a paramagnetic iron spike structure.

[0006] The soft magnetic receiver added to the robotic arm generates an electromagnetic field when energized, which interacts with the magnetically insulated package. This causes the magnetically insulated package to be fully guided and magnetically levitated within the cavity of the soft magnetic receiver. When the robotic arm moves above the magnetic fixture, the interaction force between the robotic arm and the soft magnetic receiver causes the magnetic compression spring on the soft magnetic receiver to move downwards, causing the soft magnetic receiver to open-circuit and lose magnetism. The magnetically insulated package then changes from a magnetically levitated state to move in the opposite direction to the magnetic field force of the magnetic fixture until it is inserted into the bottom of the outer shell and fixed, thus completing the sensor encapsulation and fixation.

[0007] Preferably, the device further includes a thermistor disposed within the device cavity. The thermistor is connected to a wire harness above it. The wire harness passes through a wire hole at the upper end of the ceramic body and extends to the outside of the ceramic body. A sealing silicone granule is disposed below the thermistor and is fixed to the lower port of the device cavity. An adhesive inlet is provided on the sealing silicone granule.

[0008] Preferably, it also includes a housing, within which the ceramic body is encapsulated.

[0009] The present invention provides a magnetic fixture, which is used in conjunction with the aforementioned magnetic insulating package for sensors. The fixture includes a flexible tooling base, the top of which is provided with a housing mounting hole, the housing being placed in the housing mounting hole, and a magnetic component being provided at the lower part of the housing mounting hole.

[0010] Preferably, the tooling base is made of soft silicone material; the size of the mounting holes in the housing is smaller than that of the outer shell.

[0011] Preferably, the magnetic component includes a strong magnet A, a strong magnet B, and a strong magnet C. The strong magnet A and the strong magnet B are fixed together in a left-right arrangement. Grooves are provided on the facing surfaces of the strong magnets A and B. The two grooves are assembled to form a magnetic attraction hole. The magnetic attraction hole is arranged coaxially with the mounting hole of the housing. The strong magnet C is located at the bottom of the magnetic attraction hole.

[0012] Preferably, the bottom of the tooling base is provided with an embedding groove at a position corresponding to the mounting hole of the housing, and the magnetic component is disposed in the embedding groove.

[0013] This invention provides a soft magnetic retractor, which is used in conjunction with the aforementioned magnetic fixture and sensor magnetic insulation encapsulation. The soft magnetic retractor is mounted on a robotic arm and includes a guide port. A spring is wound around the guide port, and a magnetic ring made of soft magnetic material is fixed to the upper end of the spring. The magnetic ring rests against the positive pole, and the lower end of the spring is connected to the negative pole.

[0014] Preferably, the guide port is assembled from two semi-circular bodies on the left and right.

[0015] This invention provides a fully automated assembly process for temperature sensors using the aforementioned magnetic insulating encapsulation, magnetic fixture, and soft magnetic transceiver, comprising the following steps:

[0016] The first step is to install magnetic components in the tooling fixture in advance;

[0017] The second step is to insert the outer casing into the mounting holes of the tooling;

[0018] The third step is to apply adhesive to the outer casing.

[0019] Fourth step, place the ceramic body at the guide port;

[0020] The fifth step is to energize the positive and negative electrodes so that the magnetic ring of soft magnetic material generates a magnetic field in the guide opening. The magnetic field generates a magnetic force on the ceramic body to correct the direction of movement of the ceramic body and keep the ceramic body in the guide opening.

[0021] Step 6: The robotic arm moves the guide port and the ceramic body together to above the mounting hole of the housing, and the guide port gradually approaches the tooling base. During this process, the magnetic ring is attracted by the magnetic component and moves downward, thereby compressing the spring. The magnetic ring is separated from the positive pole and instantly loses its magnetism. At the same time, the iron spinel structure in the ceramic body is attracted by the magnetic component and instantly falls into the potting compound of the outer shell.

[0022] When the guide port moves upward away from the magnetic component, the magnetic ring contacts the positive pole again under the action of the spring, generating a closed-loop magnetic field action and running back and forth periodically.

[0023] Step 7: The potting compound of the outer shell enters the device cavity through the inlet to coat the thermistor. Excess potting compound will overflow from the wire hole. During this process, the magnetic component will forcibly magnetically attract and fix the ceramic body. After the potting compound cures, the processing of the finished sensor product is completed.

[0024] Step 8: The magnetic fixture and temperature sensor are moved into the oven for heating and curing. After the sensor potting compound has cured, the power supply to the sensor fixture is cut off, causing the fixture to lose magnetism and completing the sensor fabrication.

[0025] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0026] The temperature sensor in this invention employs a ceramic magnetic insulating encapsulation, which is formed through high-temperature sintering. This imbues the ceramic with magnetic properties while maintaining its original mechanical strength and good insulation strength, thus meeting production requirements. Utilizing a magnetic field as a micro-driving force, it is applied to the fully automated production of precision electronic components. A soft magnetic take-up and release device is added to the robotic arm. Through the interaction of the magnetic field forces between the device, the fixture, and the magnetic insulating encapsulation, the device achieves automatic correction of guidance, automatic clamping, automatic feeding, automatic encapsulation, and automatic positioning. This reduces quality defects caused by uncontrollable factors in traditional sensor manufacturing processes, simplifies production procedures, and realizes the automatic assembly of the magnetic insulating encapsulation and the filling of the sensor shell with potting compound.

[0027] In summary, the present invention has the following advantages over traditional temperature sensors: First, the magnetic insulation encapsulation of the present invention reduces the complex encapsulation process of traditional sensors and the necessary curing time after encapsulation; compared with traditional production processes, the production process of the present invention has high continuity and short production cycle.

[0028] Secondly, the standardized magnetic insulation packaging of this invention increases the consistency of the sensor, and the interaction force of the magnetic field replaces the traditional gravitational force of the earth, making the tooling positioning and solidification more reliable.

[0029] Thirdly, this invention combines existing automatic wire cutting machines, automatic spot welding machines, automatic dispensing machines, and robotic arms in the market to automatically assemble and combine them into a fully automated production line. This completes the last shortcoming in the sensor production process, enabling a qualitative leap in the automated production of sensors and thus reducing the production cost of sensors. Attached Figure Description

[0030] The present invention will be further described below with reference to the accompanying drawings.

[0031] Figure 1 This is an exploded structural diagram of the magnetic insulating package of the sensor of the present invention;

[0032] Figure 2 This is a schematic diagram of the internal structure of the ceramic body of the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of the ceramic body of the present invention;

[0034] Figure 4 This is a schematic diagram of the main structure of the magnetic jig and soft magnetic receiver of the present invention;

[0035] Figure 5 This is a top view schematic diagram of the magnetic jig and soft magnetic take-up and take-down device of the present invention;

[0036] Figure 6 This is a bottom view of the magnetic fixture of the present invention.

[0037] Figure 7 This is a schematic diagram of the structure of the magnetic component of the present invention;

[0038] Figure 8 This is a schematic diagram of the strong magnets A and B of the present invention;

[0039] Figure 9 This is a schematic diagram of steps one to four of the sensor assembly process of the present invention;

[0040] Figure 10 This is a schematic diagram of step five of the sensor assembly process of the present invention;

[0041] Figure 11 This is a schematic diagram of step six in the sensor assembly process of the present invention. Figure 1 ;

[0042] Figure 12 This is a schematic diagram of step six in the sensor assembly process of the present invention. Figure 2 ;

[0043] Figure 13 This is a schematic diagram of step seven in the sensor assembly process of the present invention;

[0044] Figure 14 This is a schematic diagram of the assembled sensor product of the present invention.

[0045] Explanation of reference numerals in the attached drawings: 100, magnetic insulated package; 200, soft magnetic receiver; 300, magnetic fixture; 1, tooling base; 101, embedding groove; 2, housing mounting hole; 3, magnetic component; 301, strong magnet A; 302, strong magnet B; 303, groove; 304, magnetic suction hole; 305, strong magnet C; 4, guide port; 401, semi-circular body; 5, spring; 501, positive pole; 502, negative pole; 6, sensor magnetic insulated package; 601, thermistor; 602, wire harness; 603, sealing silicone pellet; 604, glue inlet; 605, wire hole; 606, ceramic body; 607, device cavity; 608, magnetic powder sintering cavity; 609, spinel-type structure; 610, outer shell; 7, magnetic ring. Detailed Implementation

[0046] To make the technical problems, technical solutions, and beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0047] like Figures 1 to 3As shown, this embodiment discloses a sensor magnetic insulating package 100. The magnetic insulating package 100 includes a ceramic body 606. The upper end of the ceramic body 606 is a wire hole 605, and the lower end is a device cavity 607 communicating with the wire hole 605. Magnetic powder sintering cavities 608 are provided on both sides of the ceramic body 606. The magnetic powder sintering cavities 608 are filled with a mixed powder of Fe3O4 and Al2O3. The mixed powder of Fe3O4 and Al2O3 is sintered at 1300 degrees to form a spinel-type structure 609. The spinel-type structure 609 has paramagnetic characteristics.

[0048] During the processing of the magnetic insulating encapsulation of the sensor: First step: Obtain the ceramic body (Al2O3) blank through dry powder die casting or injection molding. Second step: The ceramic body is filled with a sintering cavity, and a mixture of iron(III) oxide (Fe3O4) and aluminum(Al2O3) powder (in a ratio of 2:1) is injected into the sintering cavity through in-mold die casting or in-mold injection molding. Third step: The mixture of iron(III) oxide and aluminum(Al2O3) is sintered and solidified at a high temperature of 1300 degrees Celsius (chemical reaction formula: Fe3O4 + 2Al2O3 → 3FeAl2O4 + O2(↑)). Then, the temperature is raised to 1600 degrees Celsius to sinter the outer ceramic body (alumina) to obtain a magnetic insulating encapsulation with an outer component of Al2O3 and an inner component of FeAl2O4, so that the ceramic body 606 has the characteristics of spinel-type paramagnetic structure. (When the external permanent magnetic field and the electromagnetic field approach each other, they will generate an attraction force. When the external permanent magnetic field and the electromagnetic field are dispersed, they will lose magnetism instantly.) The spinel-type structure is set in the sintering cavity of the ceramic body: thus the ceramic body has the paramagnetic characteristics of a magnet, and at the same time has the super insulation of ceramics. Together with the thermistor and the wire harness, it is referred to as the sensor magnetic insulation package in this invention.

[0049] The sensor's magnetically insulated package 6 also includes a thermistor 601 and a housing 610. The thermistor 601 is disposed within the device cavity 607 and is connected to a wiring harness 602 above it. The wiring harness 602 passes through a wire hole 605 at the upper end of the ceramic body 606 and extends to the outside of the ceramic body 606. A sealing silicone granule 603 is disposed below the thermistor 601 and is fixed to the lower port of the device cavity 607. The sealing silicone granule 603 has an adhesive inlet 604. After the above structure is assembled into the ceramic body 606, the ceramic body 606 is encapsulated within the housing 610 using potting compound. The housing 610 has a closed bottom and an open top structure.

[0050] like Figures 4 to 8 As shown, this embodiment discloses a magnetic fixture 300, which cooperates with the sensor magnetic insulation package 100 described above. The magnetic fixture 300 includes a tooling base 1 made of flexible material, which is used to fix the outer shell 610.

[0051] A housing mounting hole 2 is provided on the top of the fixture 1. The housing 610 is placed in the housing mounting hole 2. A magnetic component 3 is provided at the lower part of the housing mounting hole 2. The magnetic component 3 is used to adsorb and fix the magnetically insulated encapsulation of the sensor (i.e., the spinel-type structure 609 sintered on the ceramic body 606). The fixture 1 is made of soft silicone material. The size of the housing 610 is larger than the housing mounting hole 2. When the housing 610 is placed in the housing mounting hole 2, a tight fit and fixation are achieved.

[0052] In this embodiment, the bottom of the tooling base 1 is provided with an embedding groove 101 at the position corresponding to the housing mounting hole 2, and the magnetic component 3 is disposed in the embedding groove 101.

[0053] Magnetic component 3 includes strong magnets A301, B302, and C305. Strong magnets A301 and B302 are fixed together in a left-right arrangement. Grooves 303 are provided on the facing surfaces of both strong magnets A301 and B302. Two grooves 303 are assembled to form a magnetic attraction hole 304, which is coaxially arranged with the housing mounting hole 2. Strong magnet C305 is located at the bottom of the magnetic attraction hole 304 and is fixed to strong magnets A301 and B302.

[0054] like Figures 4 to 8 As shown, this embodiment discloses a soft magnetic receiver 200, which is used in conjunction with the aforementioned magnetic fixture 300 and sensor magnetic insulating package 100. The soft magnetic receiver 200 includes a guide port 4, which is used to guide the ceramic body 606 into the housing 610. The guide port 4 is flared, wider at the top and narrower at the bottom, and is assembled from two semi-circular bodies 401.

[0055] A spring 5 is wound around the guide port 4. A magnetic ring 7 made of soft magnetic material is fixed to the upper end of the spring 5. The magnetic ring 7 rests against the positive electrode 501. The lower end of the spring 5 is fixedly connected to the negative electrode 502. When the positive electrode 501 and the negative electrode 502 are energized, the magnetic ring 7 made of soft magnetic material can become magnetic.

[0056] Magnetic ring 7 is made of soft magnetic ferrite material, which is a ferrimagnetic oxide material with Fe2O3 as its main component. It is manufactured using powder metallurgy and is primarily used in electronic components operating in high-frequency, weak-field environments. Soft magnetic materials have very low coercivity and can be repeatedly magnetized in a magnetic field. When the external electric field is removed, the acquired magnetism disappears completely or largely. Soft magnetic ferrite material itself is not magnetic; it only generates magnetism when an external current or magnetic field is applied, and the magnetism disappears immediately after the external excitation is removed.

[0057] like Figures 9 to 14As shown, this embodiment also discloses a process for fully automated assembly of temperature sensors using the aforementioned magnetic insulating encapsulation, magnetic fixture, and soft magnetic receiver. This assembly process specifically includes the following steps:

[0058] First, set up the magnetic component 3 in the tooling base 1 in advance; install the thermistor 601 into the device cavity 607 of the ceramic body 606 and connect it with the wire harness 602, and then seal the lower port of the device cavity 607 with the sealing silicone pellet 603.

[0059] The second step is to insert the outer casing 610 into the casing mounting hole 2;

[0060] The third step is to inject adhesive into the interior of the outer casing 610;

[0061] Fourth step, place the ceramic body 606 at the guide port 4;

[0062] Fifth step, energize the positive electrode 501 and the negative electrode 502 so that the magnetic ring 7 of soft magnetic material generates a magnetic field in the guide port 4. The magnetic field generates a magnetic force on the spinel-type structure 609 in the ceramic body 606, which is used to correct the movement direction of the ceramic body 606 and keep the ceramic body 606 in the guide port 4.

[0063] Step 6: The robotic arm moves the guide port 4 and the ceramic body 606 together to the top of the housing mounting hole 2. When the robotic arm moves along the X and Y axes (planar motion), it functions as a clamping device and causes the guide port 4 to gradually approach the tooling seat 1. During this process, the magnetic ring 7 is attracted by the magnetic component 3 and moves downward, thereby compressing the spring 5. The magnetic ring 7 is separated from the positive pole 501 and instantly loses its magnetism. At the same time, the spinel-type structure 609 in the ceramic body 606 is attracted by the magnetic component 3 and instantly falls into the potting compound inside the housing 610.

[0064] When the guide port 4 moves upward away from the magnetic component 3, the magnetic ring 7, under the action of the spring 5, comes into contact with the positive electrode 501 again, generating a closed-loop magnetic field action, and runs back and forth in a periodic cycle.

[0065] In the seventh step, the potting compound inside the outer shell 610 enters the device cavity 607 through the inlet 604 to coat the thermistor 601. Excess potting compound will overflow from the wire hole 605. During this process, the magnetic component 3 will forcibly magnetically attract and fix the ceramic body 606. After the potting compound cures, the processing of the finished sensor product can be completed.

[0066] Step 8: The magnetic fixture and temperature sensor are moved into the oven for heating and curing. After the sensor potting compound has cured, the power supply to the sensor fixture is cut off, causing the fixture to lose magnetism and completing the sensor fabrication.

[0067] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A magnetically insulated package (100) for a sensor, characterized in that: The device includes a ceramic body (606) and a shell (610). The ceramic body (606) is encapsulated in the shell (610) with potting compound. The upper end of the ceramic body (606) is a wire hole (605), and the lower end is a device cavity (607) communicating with the wire hole (605). Magnetic powder sintering cavities (608) are provided on both sides of the ceramic body (606). A mixture of Fe3O4 and Al2O3 powders in a ratio of 2:1 is injected into the magnetic powder sintering cavity (608) by in-mold die casting or in-mold injection molding. The mixture is then sintered and solidified at a high temperature of 1300 degrees Celsius, and then heated to 1600 degrees Celsius to sinter the outer ceramic body, resulting in a magnetic insulating encapsulation with an outer component of Al2O3 and an inner component of FeAl2O4 in the magnetic powder sintering cavity (608), giving the ceramic body (606) the characteristics of a paramagnetic iron spinel-type structure. It also includes a thermistor (601), which is disposed inside the device cavity (607); the thermistor (601) is connected to the upper wire harness (602), the wire harness (602) passes through the wire hole (605) at the upper end of the ceramic body (606) and extends to the outside of the ceramic body (606); a sealing silicone particle (603) is disposed below the thermistor (601), the sealing silicone particle (603) is fixed to the lower port of the device cavity (607), and an inlet (604) is provided on the sealing silicone particle (603); It also includes a magnetic fixture (300), which includes a tooling base (1) made of flexible material, a housing mounting hole (2) is provided on the top of the tooling base (1), the housing (610) is placed in the housing mounting hole (2), and a magnetic component (3) is provided at the lower part of the housing mounting hole (2). It also includes a soft magnetic retractor (200) mounted on a robotic arm. The soft magnetic retractor (200) includes a guide port (4), around which a spring (5) is wound. A magnetic ring (7) made of soft magnetic material is fixed to the upper end of the spring (5). The magnetic ring (7) rests against the positive pole (501). The lower end of the spring (5) is connected to the negative pole (502). The soft magnetic receiver (200) added to the robotic arm generates an electromagnetic field when energized, which interacts with the magnetic insulating package (100). This causes the magnetic insulating package (100) to complete the guiding and magnetic suspension actions within the cavity of the soft magnetic receiver (200). When the robotic arm moves above the magnetic fixture (300), it interacts with the soft magnetic receiver (200) under the magnetic field force, causing the magnetic ring (7) on the soft magnetic receiver (200) to compress the spring (5) downward, causing the soft magnetic receiver (200) to open-circuit and lose magnetism. The magnetic insulating package (100) changes from a magnetic suspension state to moving in the opposite direction to the magnetic field force of the magnetic fixture (300) until it is inserted into the bottom of the outer shell (610) and fixed, thus completing the sensor encapsulation and fixing.

2. The sensor magnetic insulating package according to claim 1, characterized in that: The magnetic component (3) includes a strong magnet A (301), a strong magnet B (302) and a strong magnet C (305). The strong magnet A (301) and the strong magnet B (302) are fixed together in a left-right arrangement. The strong magnet A (301) and the strong magnet B (302) are provided with grooves (303) on their facing surfaces. The two grooves (303) are assembled to form a magnetic suction hole (304). The magnetic suction hole (304) is arranged coaxially with the housing mounting hole (2). The strong magnet C (305) is located at the bottom of the magnetic suction hole (304).

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