CN102384486A - Ni-Cr alloy thin film igniter with low ignition voltage and preparation method thereof - Google Patents

Abstract

The invention discloses a Ni-Cr alloy film bridge igniter with low firing voltage and a preparation method thereof, belonging to the technical field of pyrotechnics. The Ni-Cr alloy film bridge igniter with low firing voltage includes a base, and the base An isolation film is provided on the isolation film, an ignition element is arranged on the isolation film, and an igniter lead pad area is arranged on the ignition element; the material of the ignition element is Ni-Cr alloy. The invention adopts micro-machining technology to prepare the igniter. The invention realizes reliable ignition at lower ignition voltage, the ignition voltage is as low as 4.8V/10μF, the ignition energy is as low as 110mJ, and has good vibration resistance.

Description

A Ni-Cr alloy film bridge igniter with low ignition voltage and its preparation method

technical field

The invention belongs to the technical field of pyrotechnics, and relates to an alloy film bridge igniter based on micromachining technology and a preparation method thereof. More specifically, the present invention relates to an igniter whose igniter element is composed of Ni-Cr alloy film bridges and can reliably fire at relatively low igniting voltage and energy.

Background technique

Electrical explosives mainly include bridge wire electrical explosives and film bridge electrical explosives. The film bridge pyrotechnics include semiconductor bridge pyrotechnics, metal film bridge pyrotechnics and explosive film bridge pyrotechnics. The bridge wire pyrotechnic device is an ignition method commonly used by people. It is composed of a suspended resistance heating wire and two electrodes. This technology mainly has the following disadvantages:

a) The process consistency level in the production of the bridge wire igniter is poor, and the performance of the igniter cannot be accurately predicted during use;

b) In a strong vibration environment, the radial stretching effect of the bridge wire is likely to cause the deformation of the bridge wire, which may cause the breakage of the bridge wire and the cracking and desoldering of the solder joints, resulting in the igniter not working normally and reducing the bridge wire ignition. level of device reliability;

c) The bridge wire igniter cannot meet the requirements of low ignition energy and rapid ignition.

The metal film bridge igniter deposits the bridge material on the substrate by physical vapor deposition (PVD). The resistance value of the film bridge is determined by its geometric shape. In practice, different resistances can be obtained by changing the length, width and thickness of the film bridge. value. In other words, the shape structure of the metal film bridge can be designed according to different performance requirements to meet different functions, which is one of the most prominent advantages of the metal film bridge igniter. Since the metal film bridge igniter deposits the metal film directly on the substrate by physical vapor deposition, the adhesion between the metal film and the substrate is strong, and in the process of bearing overload, the metal film bridge does not move radially. There is a stretching effect, and there will be no breakage and shedding of the metal film bridge. The use of micromachining technology to prepare metal thin film bridge igniters on the substrate can simultaneously manufacture hundreds of thousands of metal thin film bridge ignition elements on a substrate, improve processing efficiency, processing repeatability and controllability of processing dimensions, and Greatly reduce manufacturing costs.

In view of the above problems, there is a need for a metal film bridge igniter that can ignite reliably at a lower ignition voltage.

Contents of the invention

Aiming at the defects of relatively high ignition voltage and relatively long ignition time in the prior art, the present invention aims to provide a Ni-Cr alloy film bridge igniter and its preparation method, which can reliably ignite at a relatively low ignition voltage , and has good anti-vibration performance.

In order to achieve the above object, the technical solution adopted in the present invention is: the Ni-Cr alloy film bridge igniter with low ignition voltage includes a base, and its structural feature is that an isolation film is arranged on the base, and An ignition element is provided, and the ignition element is provided with an igniter lead pad area, and the material of the ignition element is Ni-Cr alloy.

The isolation film is a dielectric film with low thermal conductivity, preferably a SiO2 isolation film, with a thickness of 0.5 μm˜1 μm. Wherein, the material of the substrate is selected from at least one of FR-4, polyimide, and Al ₂ O ₃ , the diameter of the substrate is 50mm-100mm, and the thickness is 0.5mm-1mm. Wherein, the material of the pad area of the lead wire of the igniter is selected from at least one of aluminum, copper, gold, and silver, and the thickness of the pad area of the lead wire of the igniter is 0.1 μm˜1 μm.

In use, the lead pad area of the igniter is connected with a lead pad area on a base for installing the igniter through wires.

Furthermore, the thickness of the film is one of the decisive factors affecting the performance of the igniter. The value of the film thickness can be determined according to the product characteristics and requirements to obtain different product performances. The thickness of the above-mentioned ignition element is preferably not greater than 2×10 ^-7 m～ 5×10 ^-6 m.

The ratio of Ni and Cr in the ignition element is preferably 80:20.

Further, the present invention provides a method for preparing the above-mentioned Ni-Cr alloy film bridge igniter with low ignition voltage, which comprises the following steps:

1) Clean the substrate to remove oil and impurities on the surface of the substrate;

2), depositing an isolation film on the substrate, and depositing a Ni-Cr alloy thin film on the isolation film;

3), preparing a photoresist mask layer on the Ni-Cr alloy film, using photoresist as a mask material to etch the ignition element, and the etching depth is the thickness of the Ni-Cr alloy film;

4), prepare a photoresist mask layer on the igniter element layer, and use physical vapor deposition technology to deposit the igniter lead pad area;

5) Slicing with a slicer to produce a Ni-Cr alloy film bridge igniter.

In the step 3), a photoresist mask layer in the shape of an ignition element is prepared by a photolithography process on the Ni-Cr alloy film, and then a dry etching technique is used to etch the Ni-Cr alloy film into Ignition element.

In the step 4), a photoresist mask layer in the shape of the pad area of the lead wire of the igniter is prepared on the ignition element layer by photolithography, and the pad area of the lead wire of the igniter is deposited by physical vapor deposition technology.

Compared with the prior art, the beneficial effect of the present invention is: the present invention adopts the micromachining technology, which is conducive to improving the consistency of the processing technology and the reliability level of the igniter, and can realize the mass production of the igniter, effectively reducing the manufacturing cost. The invention adopts a Ni-Cr alloy thin film bridge, so that the ignition voltage is as low as 4.8V/10μF, and the ignition energy is as low as 110mJ, which meets the requirement for ignition devices with lower ignition energy. The invention adopts the base material and the isolation film material with lower thermal conductivity, which effectively reduces the loss of heat, improves the reaction rate of the igniter, and shortens the ignition time. The invention adopts ion beam etching technology to prepare Ni-Cr alloy thin film bridge ignition element, which can obtain Ni-Cr alloy thin film bridge structure with high side steepness and good uniformity between sheets and inside sheet, and greatly improves the consistency of processing technology level and reliability level of igniter operation. The invention utilizes the micromachining technology to simultaneously manufacture hundreds or even thousands of metal thin film bridge ignition elements on a substrate, improves processing efficiency, processing repeatability and controllability level of processing size, and greatly reduces manufacturing cost.

The present invention will be further elaborated below in conjunction with the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is a top view of an embodiment of the present invention;

Fig. 2 is a sectional view of Fig. 1;

Fig. 3 is a top view of the array arrangement in Fig. 1;

Fig. 4 is a top view of Fig. 1 with lead wire welding;

Fig. 5 is a schematic diagram of the ignition circuit of the present invention.

In the picture:

1-Ni-Cr alloy film bridge igniter; 2-substrate; 3-isolation film;

4-ignition element; 5A, 5B-igniter lead pad area; 6-lead pad area;

7-base; 8-lead.

Detailed ways

A Ni-Cr alloy film bridge igniter with low ignition voltage, as shown in Figures 1 to 3, includes a base 2, and the base 2 is provided with a _SiO2 isolation film 3, and the isolation film 3 is provided with a thickness not greater than The ignition element 4 of 5×10 ^-6 m is provided with the igniter lead pad area 5A, 5B on the igniter element 4, as shown in Figure 4, the igniter lead pad area 5A, 5B is connected with a wire 8 for The lead pad area 6 on the base 7 where the igniter 1 is installed is connected; the material of the ignition element 4 is Ni-Cr alloy, wherein the ratio of Ni and Cr is 80:20. The material of the base 2 is selected from at least one of FR-4, polyimide, and Al ₂ O ₃ ; the material of the igniter lead pad area 5A, 5B is selected from aluminum, copper, gold, and silver. at least one of .

The preparation method of the Ni-Cr alloy film bridge igniter of low firing voltage of the present invention, carries out according to the following steps successively:

a) cleaning the FR-4 substrate 2 with a diameter of 50 mm to 100 mm and a thickness of 0.5 mm to 1 mm to remove oil stains and impurities on the polished surface of the substrate;

b) using ion beam sputtering to deposit a _SiO2 isolation film 3 with a thickness of 0.5 μm to 1 μm to reduce heat loss to the substrate 2 and to enhance the bonding force between the Ni-Cr alloy thin film layer and the substrate layer 2;

c) Ion beam sputtering deposits a Ni-Cr alloy thin film layer with a thickness of 0.2 μm to 5 μm, which is used as an ignition material;

d) On the Ni-Cr alloy film, use photolithography to make a photoresist mask layer in the shape of the firing element, and use ion beam dry etching to remove unnecessary alloy film regions to form a Ni-Cr alloy film bridge structure ;

e) Making a photoresist mask layer by using a photolithography process to protect the thin film layer outside the wire bonding area;

f) Ion beam sputtering deposits the Au wire bonding regions 5A, 5B with a thickness of 0.1 μm˜1 μm, and completes the preparation of the Ni—Cr alloy thin film bridge igniter 1 after stripping and cleaning.

As shown in Figure 5, it is a schematic diagram of the ignition circuit of the Ni-Cr alloy thin film bridge igniter described in this embodiment. About 110 microjoules, or in other words, the igniter of the present invention can reliably ignite at a very low energy of 1.1×10 ^-4 J.

The above-mentioned embodiments should be understood that these embodiments are only used to illustrate the present invention more clearly, and are not intended to limit the scope of the present invention. After reading the present invention, those skilled in the art will understand the various equivalent forms of the present invention All modifications fall within the scope defined by the appended claims of the present application.

Claims (10)

1. a kind of Ni-Cr alloy thin film bridge igniter of low firing voltage, comprise substrate (2), it is characterized in that, described substrate (2) is provided with barrier film (3), and this barrier film (3) is provided with There is an ignition element (4), and the ignition element (4) is provided with an igniter lead pad area (5A, 5B); the material of the ignition element (4) is Ni-Cr alloy. 2. the Ni-Cr alloy thin film bridge igniter of low ignition voltage according to claim 1, is characterized in that, this igniter lead pad area (5A, 5B) is used for installing described by lead wire (8) and one. The lead pad area (6) on the base (7) of the igniter (1) is connected. 3. the Ni-Cr alloy film bridge igniter of low firing voltage according to claim 1, is characterized in that, the material of described substrate (2) is selected from FR-4, polyimide, Al ₂ O ₃ At least one of the substrates (2) has a diameter of 50 mm to 100 mm and a thickness of 0.5 mm to 1 mm. 4. the Ni-Cr alloy thin film bridge igniter of low firing voltage according to claim 1 is characterized in that, the material of described igniter lead pad area (5A, 5B) is selected from aluminum, copper, gold, silver At least one of them, the thickness of the igniter lead pad area (5A, 5B) is 0.1 μm˜1 μm. 5. The Ni-Cr alloy film bridge igniter with low ignition voltage according to claim 1, characterized in that the thickness of the ignition element (4) is 2×10 ^-7 m˜5×10 ^-6 m. 6. The Ni-Cr alloy film bridge igniter with low ignition voltage according to claim 1, characterized in that the ratio of Ni and Cr in the ignition element (4) is 80:20. 7. The Ni-Cr alloy film bridge igniter with low firing voltage according to claim 1, characterized in that the material of the isolation film (3) is SiO ₂ and the thickness is 0.5 μm-1 μm. 8. A method for preparing a Ni-Cr alloy film bridge igniter (1) with low ignition voltage as claimed in one of claims 1 to 7, characterized in that: it comprises the steps of: 1) Clean the base (2) to remove oil and impurities on the surface of the base (2); 2), depositing an isolation film (3) on the substrate (2), and depositing a Ni-Cr alloy thin film on the isolation film (3); 3), prepare a photoresist mask layer on the Ni-Cr alloy film, use photoresist as a mask material to etch the ignition element (4), and the etching depth is the thickness of the Ni-Cr alloy film; 4), preparing a photoresist mask layer on the ignition element (4) layer, and depositing the igniter lead pad area (5A, 5B) by physical vapor deposition technology; 5) Slicing with a microtome to prepare the Ni-Cr alloy film bridge igniter (1). 9. the preparation method of the Ni-Cr alloy thin film bridge igniter (1) of low firing voltage according to claim 8 is characterized in that: in described step 3), utilize light on described Ni-Cr alloy thin film A photoresist mask layer in the shape of the ignition element (4) is prepared by an etching process, and a Ni-Cr alloy thin film is etched into the ignition element (4) by using a dry etching technique. 10. the preparation method of the Ni-Cr alloy thin film bridge igniter (1) of low ignition voltage according to claim 8, it is characterized in that: in described step 4), utilize photoetching on the ignition element (4) layer The process prepares a photoresist mask layer in the shape of the pad area (5A, 5B) of the lead wire of the igniter, and deposits the pad area (5A, 5B) of the lead wire of the igniter by using a physical vapor deposition technique.

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