阅读说明：本技术 航天器用耐辐照型薄膜电加热器及其制造工艺 (Radiation-resistant film electric heater for spacecraft and manufacturing process thereof ) 是由 杨贵 李晨 彭帅 于 2020-05-12 设计创作，主要内容包括：本发明公开了一种航天器用耐辐照型薄膜电加热器,包括上下重叠的两层聚酰亚胺薄膜,在两层所述聚酰亚胺薄膜之间设置有电热合金箔,所述电热合金箔焊接有引出线,在上层所述聚酰亚胺薄膜的下表面和下层聚酰亚胺薄膜的上表面均涂覆有一层聚酰亚胺热熔胶膜。本发明还公开了一种航天器用耐辐照型薄膜电加热器制造工艺。本发明的电加热器的耐辐照总剂量提高至1.0×10<Sup>9</Sup>rad(SI),能够满足航天器舱外使用环境要求,可以满足更高的使用温度区间,电加热器的长期使用最高温度提高至230℃。(The invention discloses an irradiation-resistant film electric heater for a spacecraft, which comprises two layers of polyimide films which are overlapped up and down, wherein an electric heating alloy foil is arranged between the two layers of polyimide films, an outgoing line is welded on the electric heating alloy foil, and a layer of polyimide hot melt adhesive film is coated on the lower surface of the upper layer of polyimide film and the upper surface of the lower layer of polyimide film 9 rad (SI) can meet the requirement of the using environment outside the spacecraft cabin, can meet a higher using temperature range, and the maximum temperature of the electric heater in long-term use is increased to 230 ℃.)

1. The utility model provides an irradiation resistant type film electric heater for spacecraft, includes two-layer polyimide film of upper and lower overlapping, it is two-layer be provided with electric heating alloy foil between the polyimide film, electric heating alloy foil welding has lead-out wire, its characterized in that: and a layer of polyimide hot melt adhesive film is coated on the lower surface of the upper layer of polyimide film and the upper surface of the lower layer of polyimide film.

2. The radiation-resistant thin-film electric heater for the spacecraft defined in claim 1, wherein: and a plurality of layers of polyimide hot melt adhesive films are arranged at the welding position of the electric heating alloy foil and the outgoing line.

3. The radiation-resistant thin-film electric heater for the spacecraft defined in claim 1, wherein: the electrothermal alloy foil is a copper-nickel alloy foil.

4. The radiation-resistant thin-film electric heater for the spacecraft defined in claim 1, wherein: the outgoing line is composed of a plurality of strands of copper wires.

5. The manufacturing process of the irradiation-resistant thin film electric heater for the spacecraft is characterized by comprising the following steps of:

step one, coating a layer of polyimide hot melt adhesive film on the lower surface of an upper layer of polyimide film and the upper surface of a lower layer of polyimide film to prepare an upper layer of insulating layer and a lower layer of insulating layer;

step two, thermally compounding the electrothermal alloy foil and the lower insulating layer together through a thermal compound machine to form a compound foil, wherein the control parameters of the thermal compound machine are in a high-temperature maintaining stage, the temperature range of the compound layer is 360℃ +/-10 ℃, the temperature range of the insulating layer is 340℃ +/-10 ℃, the temperature reduction stage is that the temperature reduction rate of the compound layer is 3-5 ℃/min, and the temperature reduction rate of the insulating layer is 3-5 ℃/min;

step three, manufacturing a resistance foil on the composite foil through a pattern transfer process;

welding the outgoing line and the resistance foil;

placing a plurality of layers of polyimide hot melt adhesive films at the welding position, and thermally compounding the upper insulating layer, the composite foil, the outgoing line and the plurality of layers of polyimide hot melt adhesive films together through a thermal compound machine to form a whole, wherein the control parameters of the thermal compound machine are in a high-temperature maintaining stage, the temperature range of the composite layer is 350 +/-10 ℃, the temperature range of the heat preservation layer is 330 +/-10 ℃, and in a cooling stage, the temperature cooling rate of the composite layer is 3-5 ℃/min, and the temperature cooling rate of the heat preservation layer is 3-5 ℃/min.

6. The process of claim 5, wherein the pattern of the resistive foil in step two is determined by the following method:

(a) designing the line width, line spacing, line number and effective heating size of the resistor foil according to the ohm law;

(b) and drawing the graph of the resistance foil according to the size of the insulating layer.

Technical Field

The invention belongs to the field of thin film electric heaters, and particularly relates to an irradiation-resistant thin film electric heater for a spacecraft and a manufacturing process thereof.

Background

The thickness of the existing silicon rubber film electric heater, urea-formaldehyde film electric heater and epoxy film electric heater is more than 1.5mm, the mass is more than 0.10g/cm2, the existing silicon rubber film electric heater, urea-formaldehyde film electric heater and epoxy film electric heater are not easy to bend, are not resistant to irradiation, are not suitable for the condition of limited space and are not suitable for vacuum occasions, so the existing silicon rubber film electric heater, urea-formaldehyde film electric heater and epoxy film electric.

The polyimide film electric heater has good flexibility and small thickness, and can be widely used on an aircraft, but the existing polyimide film electric heater can only resist the total radiation dose not more than 1.0 × 10⁷The radiation dose of the rads (SI) spacecraft cabin is 1.0 × 10⁹rad (SI), therefore, the existing polyimide film electric heater can not be applied to the environment outside the spacecraft cabin, and meanwhile, the maximum service temperature of the existing polyimide film electric heater is 125 ℃, and the requirement of higher service temperature cannot be met.

Disclosure of Invention

In view of the above technical problems, a first object of the present invention is to provide an irradiation-resistant thin film electric heater for spacecraft, which has good irradiation resistance and can be used in an environment outside a spacecraft cabin, and a second object of the present invention is to provide a manufacturing process of the electric heater.

In order to achieve the first object, the invention adopts the technical scheme that: the utility model provides an irradiation-resistant type film electric heater for spacecraft, includes two-layer polyimide film that overlaps from top to bottom, it is two-layer be provided with electric heating alloy foil between the polyimide film, electric heating alloy foil welds there is the lead-out wire, at the upper strata the lower surface of polyimide film and the upper surface of lower floor's polyimide film all coat has one deck polyimide hot melt adhesive membrane.

Preferably, a plurality of layers of polyimide hot melt adhesive films are arranged at the welding position of the electrothermal alloy foil and the lead wire. By adopting the structure, the irradiation resistance of the electric heater is further improved, and the total mass loss and the condensable volatile matter are reduced.

Preferably, the electrothermal alloy foil is a copper-nickel alloy foil. By adopting the structure, the heating performance of the copper-nickel alloy foil is stable and reliable.

Preferably, the lead wire is composed of a plurality of strands of copper wire. By adopting the structure, the structure is stable and the use is reliable.

The second purpose of the invention is realized by that the manufacturing process of the radiation-resistant thin-film electric heater for the spacecraft comprises the following steps:

step one, coating a layer of polyimide hot melt adhesive film on the lower surface of an upper layer of polyimide film and the upper surface of a lower layer of polyimide film to prepare an upper layer of insulating layer and a lower layer of insulating layer;

step two, thermally compounding the electrothermal alloy foil and the lower insulating layer together through a thermal compound machine to form a compound foil, wherein the control parameters of the thermal compound machine are in a high-temperature maintaining stage, the temperature range of the compound layer is 360℃ +/-10 ℃, the temperature range of the insulating layer is 340℃ +/-10 ℃, the temperature reduction stage is that the temperature reduction rate of the compound layer is 3-5 ℃/min, and the temperature reduction rate of the insulating layer is 3-5 ℃/min;

step three, manufacturing a resistance foil on the composite foil through a pattern transfer process;

welding the outgoing line and the resistance foil;

placing a plurality of layers of polyimide hot melt adhesive films at the welding position, and thermally compounding the upper insulating layer, the composite foil, the outgoing line and the plurality of layers of polyimide hot melt adhesive films together through a thermal compound machine to form a whole, wherein the control parameters of the thermal compound machine are in a high-temperature maintaining stage, the temperature range of the composite layer is 350 +/-10 ℃, the temperature range of the heat preservation layer is 330 +/-10 ℃, and in a cooling stage, the temperature cooling rate of the composite layer is 3-5 ℃/min, and the temperature cooling rate of the heat preservation layer is 3-5 ℃/min.

Preferably, the pattern of the resistive foil in step two is determined by the following method:

(a) designing the line width, line spacing, line number and effective heating size of the resistor foil according to the ohm law;

(b) and drawing the graph of the resistance foil according to the size of the insulating layer.

By adopting the method, the pattern of the resistance foil is accurate, and the heating is more uniform.

The invention has the beneficial effects that 1, the total radiation-resistant dose of the electric heater is improved to 1.0 × 10⁹rad (SI) can meet the requirements of the extravehicular use environment of the spacecraft; 2. the temperature can meet a higher use temperature range, and the maximum temperature of the electric heater in long-term use is increased to 230 ℃.

Drawings

Fig. 1 is a schematic structural diagram of an irradiation-resistant thin-film electric heater for a spacecraft of the present invention.

Detailed Description

The invention will be further illustrated by the following examples in conjunction with the accompanying drawings:

as shown in fig. 1, an irradiation-resistant thin film electric heater for a spacecraft comprises a polyimide film 1, an electrothermal alloy foil 2, lead-out wires 3 and polyimide hot melt adhesive films, wherein the two polyimide films 1 are overlapped up and down, the electrothermal alloy foil 2 is arranged between the two polyimide films 1, the lead-out wires 3 are welded at two ends of the electrothermal alloy foil 2 respectively, one polyimide hot melt adhesive film is coated on the lower surface of the upper polyimide film 1 and the upper surface of the lower polyimide film 1, and meanwhile, a plurality of layers of polyimide hot melt adhesive films are arranged at the welding positions of the electrothermal alloy foil 2 and the lead-out wires 3.

A process for manufacturing an irradiation-resistant thin film electric heater for a spacecraft comprises the following steps:

step one, coating a layer of polyimide hot melt adhesive film on the lower surface of the upper polyimide film 1 and the upper surface of the lower polyimide film 1 to prepare an upper insulating layer and a lower insulating layer.

Step two, thermally compounding the electrothermal alloy foil 2 and the lower insulating layer together through a thermal compound machine to form a compound foil, wherein the control parameters of the thermal compound machine are as follows: in the high-temperature maintaining stage, the temperature range of the composite layer is 360 +/-10 ℃, the temperature range of the heat preservation layer is 340 +/-10 ℃, in the temperature reduction stage, the temperature reduction rate of the composite layer is 3 ℃/min-5 ℃/min, the temperature reduction rate of the heat preservation layer is 3 ℃/min-5 ℃/min, and the electric heating alloy foil 2 is a copper-nickel alloy foil.

Step three, manufacturing a resistance foil on the composite foil through a pattern transfer process, wherein specifically, the pattern of the resistance foil is determined by the following method:

(a) designing the line width, line spacing, line number and effective heating size of the resistor foil according to the ohm law;

(b) and drawing the graph of the resistance foil according to the size of the insulating layer.

And step four, welding the outgoing line 3 and the corresponding resistance foil by using a fusion welding technology, wherein the outgoing line 3 is composed of a plurality of strands of copper wires.

Placing a plurality of layers of polyimide hot melt adhesive films at the welding position, and thermally compounding the upper insulating layer, the compound foil, the outgoing line 3 and the plurality of layers of polyimide hot melt adhesive films through a thermal compound machine to form a whole, wherein the control parameters of the thermal compound machine are in a high-temperature maintaining stage, the temperature range of the compound layer is 350 +/-10 ℃, the temperature range of the heat preservation layer is 330 +/-10 ℃, and in a cooling stage, the temperature cooling rate of the compound layer is 3-5 ℃/min, and the temperature cooling rate of the heat preservation layer is 3-5 ℃/min.

The electric heater provided by the invention has excellent performance and is suitable for the environment outside the spacecraft cabin, the electric heater test piece provided by the invention is placed in a Co-60 gamma irradiation device, the passing dose rate is 50-150 rad/s, and the total absorbed dose is not less than 1.0 × 10⁹rad (SI) (deviation +/-10%) gamma ray irradiation, and the appearance of the electric heater is unchanged; in the atmospheric environment, the product can continuously work for 500 hours at the rated working temperature of 230 +/-5 ℃; the thickness of the single-layer electric heater (only with the lower polyimide film 1) is not more than 0.15mm (excluding the soldering region); thickness of double-layer electric heaterNot more than 0.3mm (excluding the welding area); the mass per unit area of the single-layer electric heater is 0.023-0.037g/cm²The mass per unit area of the double-layer electric heater is 0.04-0.06g/cm²The single-layer electric heater is bent 100 times around a cylinder with the diameter of 15mm, the double-layer electric heater is bent 100 times around a cylinder with the diameter of 25mm, the appearance of the electric heater is unchanged, after a single outgoing line 3 is subjected to the action of 15N tension for 30min along the direction of the outgoing line 3, the appearance of the electric heater is not obviously changed, the relative change of the resistance value is not more than +/-2%, the insulation resistance is not less than 100 MOmega under the condition of 250V direct current, and the vacuum degree is better than 7 × 10^-3Pa and the temperature of 125 +/-1 ℃, and the total mass loss of the insulating layer of the electric heater is not more than 1 percent and the condensable volatile matter on the cold surface at 25 +/-1 ℃ is not more than 0.1 percent after the electric heater is kept for 24 hours.