KR100826368B1 - Pressure contact type rectifier - Google Patents

Abstract

The present invention provides a pressurized contact rectifying device that does not use a solder with a large environmental load and is free from damage or breakage of the rectifying element even when a temperature rise of the rectifying element during energization or a force acting on the lead terminal or the like is applied outside. Its purpose is to. By providing an electrically conductive friction reducing portion on at least one of the electrode surfaces of the rectifying element, the rise in temperature can be suppressed and the friction of the contact area can be reduced. In addition, the contact area of the rectifying element can be kept constant by providing the expansion and contraction portion outside the cap of the lead terminal and fixing it to the cap. As a result, it is possible to provide a pressurized contact rectifying device without burning or breaking of the rectifying element.

Description

PRESSURE CONTACT TYPE RECTIFIER

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rectifier for large currents used in, for example, electrical components of automobiles, and more particularly, to a package structure thereof.

In the conventional high current rectifier, the diode chip which is a rectifier element was fixed by low melting metals, such as solder. However, the use of the solder containing lead has a large environmental load, and the structure which does not use solder is expected.

As a structure of a rectifier without using solder, for example, Japanese Patent No. 3198693 discloses a metal stem having a male thread on its outer circumference, a metal cap having a female screw on its inner circumferential surface, a lead terminal fixed to an insulator, and a disposition on a stem. It is disclosed that an electrode is connected to one electrode, a lead terminal, and the other electrode and the stem of the diode chip by screwing the stem and the cap together with a screw. It is possible to realize that such a conventional rectifier does not use a solder containing lead, but there is a problem that a resistance increase or disconnection of a diode chip occurs during operation.

Summary of the Invention

This invention is made | formed in order to solve the above-mentioned subjects, and is to obtain the highly reliable pressurized contact type rectifier which does not have the resistance raise or disconnection during energization.

The inventors have investigated the cause of the problem as described above, and heat is generated during operation at the electrical contact resistance of the contact surface between the lead terminal and the diode chip or the contact surface between the diode chip and the stem, and the lead terminal, diode chip and stem It was found that the temperature rises and the stress concentration by friction occurs at each contact surface due to the difference in thermal expansion coefficient of each material. As a result, electrical conduction failure at the contact surface between the lead terminal and the diode chip or at the contact surface between the diode chip and the stem, damage of the diode chip due to an increase in resistance accompanying it, or breakage of the diode chip due to stress It came to know that this causes a problem, etc., and reached this invention.

A pressure-contacting rectifier according to the present invention includes a rectifier having a cap, a lead supported by an elastic body through the cap, a case that can be fitted to the cap, an end of the lead and an electrode in contact with the case. And a friction reducing portion provided on at least one of the surfaces of the electrode, and the rectifying element is press-fixed with the cap and the case.

In such a pressure-contacting rectifier, the friction reducing portion provided on the contact surface between the lead and the rectifying element or the contact surface between the rectifying element and the casing can alleviate the friction caused by the temperature rise during operation, thereby reducing the stress concentration on the contact surface. It is possible to provide a pressurized contact type rectifier with high reliability without occurrence of poor conduction, burnout of the rectifier element due to an increase in resistance, or breakage of the rectifier element due to stress.

Thus, in order to make stress concentration small in a friction reducing part, it is preferable to deform | transform a friction reducing part by stress, and it is preferable that it is formed from electroconductive fine particles. In addition, in order to improve electrical conduction between the contact surface between the lead and the rectifying element or the contact surface between the rectifying element and the case, the fine particles are made of at least one of carbon, silver, copper, gold, aluminum, and molybdenum dihydride. desirable. In addition, in order to ensure deformation amount and electrical conduction simultaneously, it is preferable that the particle diameter of microparticles | fine-particles is 0.01 micrometer or more and 50 micrometers or less. In addition, if the particle size is too small, the friction reducing portion becomes dense and the deformation amount is small. If the particle size is too large, the electrical resistance increases, so that the particle diameter of the fine particles is preferably 0.05 µm or more and 20 µm or less, and in consideration of reliability, 0.1 µm or more. It is preferable that it is 10 micrometers or less.

In addition, another pressurized contact rectifying device according to the present invention includes a cap, a lead supported by an elastic body through the cap, a case that can be fitted to the cap, an end of the lead, and an electrode in contact with the case. The rectifier is composed of a rectifying element and a friction reducing portion provided on at least one of the surfaces of the electrode, wherein the rectifying element is press-fixed and fixed to the cap and the case, and the contact portion between the rectifying element and the lead or between the rectifying element and the case A soft member is inserted into at least one of the contact portions.

In such a pressure-contacting rectifier, the soft member deforms when the cap and the case are fitted, and the contact area is increased by filling minute irregularities in the contact surface between the lead and the rectifying element or the contact surface between the case and the rectifying element. It is possible to improve the electrical conductivity and thermal conductivity between the lead, the rectifying element and the case.

In addition, another pressurized contact rectifying device according to the present invention includes a cap, a lead supported by an elastic body through the cap, a case that can be fitted to the cap, an end of the lead, and an electrode in contact with the case. The rectifier is composed of a rectifying element and a friction reducing portion provided on at least one surface of the electrode, wherein the rectifying element is press-fixed and fixed to the cap and the case, and the elastic part is provided on a lead located outside the cap. The lid is fixed to the cap.

In such a pressure-contacting rectifier, since the stretch part is provided in the lid and the lid is fixed to the cap, even if a force acting outward is applied to the lead, the stretch part is stretched to absorb the force and is located inside the cap. Since the positional shift of a component can be prevented, the contact area | region of a lead and a rectifying element does not change, and the highly reliable pressurized contact type rectification device which does not raise resistance or disconnection during energization can be provided.

In addition, another pressurized contact rectifying device according to the present invention includes a cap, a lead supported by an elastic body through the cap, a case that can be fitted to the cap, an end of the lead, and an electrode in contact with the case. It has a rectifying element and a friction reducing portion provided on at least one side of the electrode surface, and has a screw that can be fitted to the outer circumferential surface of the cap and the inner circumference of the case, and is fastened with the screw, so that the rectifying element is formed by the cap and the case It is fixed by pressure.

In such a pressure-contacting rectifier, by fitting the cap and the case with screws, the pressure-contacting rectifier can be manufactured at low cost without the need for another member for pressure-fixing of the rectifying element.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows schematic structure of the pressure-contacting rectification apparatus in Embodiment 1 of this invention.

2 is a schematic view of a pressure-contacting rectifier according to Embodiment 1 of the present invention;

3 is an explanatory diagram showing a comparison of reliability between the case where there is a friction reducing portion and the case where there is no friction reducing portion in the pressure-contacting rectifier according to the first embodiment of the present invention;

4 is an explanatory diagram showing a relationship between particle size and reliability in the third embodiment of the present invention;

5 is a schematic diagram showing a schematic configuration of a pressure-contacting rectifying device according to Embodiment 4 of the present invention;

6 is a schematic diagram showing a schematic configuration of a pressure-contacting rectifying device according to Embodiment 5 of the present invention.

In order to demonstrate this invention in more detail, this is demonstrated according to attached drawing.

Embodiment 1

FIG. 1: is a schematic diagram which shows schematic structure of the pressure contact type rectification apparatus 10 in Embodiment 1 for implementing this invention. In FIG. 1, the lead 2 penetrates the insulating cap 1 in which the external thread 1a was formed in the outer peripheral surface. The lead 2 is fixed by the insulating elastic body 3 which consists of silicone rubber, for example. The lower end of the lid 2 is a lead terminal 2a having a flat lower surface, and these are made of copper, for example. In order to fix the position of the diode chip 5 in a case 4 having a bottom portion with a female screw 4a that can be fitted with a cap 1 on an inner circumferential surface, a diode holder 6 cut out in the center is inserted. The diode chip 5 as a rectifying element is arrange | positioned at the cut part. The case 4 is formed of copper, for example, having good electrical conductivity and thermal conductivity. The site | part which contacts the diode chip 5 of the inner surface of the bottom part of the case 4 is processed especially flat in order to enlarge the contact area with the diode chip 5. For example, the flatness is improved by pressing with a flat punch to cause plastic flow. The diode holder 6 is made of, for example, PPS (polyphenylene sulfide) resin having high insulation and high heat resistance.

The upper and lower surfaces of the diode chip 5 serve as electrodes, and a carbon deposited film is formed on the surface of the diode chip 5 as the friction reducing portion 7. This carbon vapor deposition film is formed by resistance heating vapor deposition, and the film thickness is about 10 micrometers. The carbon deposited film having the above film thickness is usually not formed as a continuous film, and is composed of a laminate of fine particles having a particle diameter of about 1 m. By engaging the cap 1 and the case 4 by fitting the male screw 1a and the female screw 4a, the diode chip 5 is connected to the lead terminal 2a and the case 4 via the elastic body 3. It is firmly in pressure contact. FIG. 2 is a schematic view of the cap 1 and the case 4 fitted in a threaded portion to operate as a pressure-contacting rectifier 10.

In the pressure-contacting rectifier 10 configured as described above, the temperature of the member in contact with the diode chip 5 and the diode chip 5 is increased by heat generated during operation, and the lead terminal 2a and the diode chip 5 are raised. Even if friction occurs in each of the contact surfaces of the case 4, the friction reducing portion 7 can alleviate the stress concentration caused by the friction. Specifically, the warp of the contact surface is alleviated by the movement or rotation of the fine particles of the carbon vapor deposition film constituting the friction reducing portion 7. As a result, even if it is operated for a long time, the pressurized contact type rectification device which does not burn out the diode chip 5 etc. can be provided. 3 is a comparison of the reliability in the case where the friction reducing portion 7 is formed on the surface of the diode chip 5 in this embodiment (A) and when the friction reducing portion 7 is not formed (B). It is explanatory drawing which shows the. 3 shows that the provision of the friction alleviation part 7 reduces the defect occurrence rate, and improves the reliability of the pressure-contacting rectifier.

Embodiment 2

In the first embodiment, a carbon deposition film is formed as the friction reducing portion 7 on the electrode surface of the diode chip 5, but in the present embodiment, metal, for example, silver is deposited as the friction reducing portion 7. will be. The vapor-deposited film is composed of a laminate having a particle diameter of 0.5 m and a film thickness of about 5 m. In the pressure-contacting rectifier 10 configured as described above, the temperature around the diode chip 5 and the diode chip 5 increases due to heat generated during operation, and leads the lead terminal 2a, the diode chip 5, and the case ( Even when friction occurs at each of the contact surfaces of 4), the fine particles of silver constituting the friction reducing portion 7 move, whereby stress concentration caused by friction can be alleviated. As a result, even if it is operated for a long time, the pressurized contact type rectification device which does not burn out the diode chip 5 etc. can be provided.

In addition, in this embodiment, although the vapor deposition film of silver was used as the friction reduction part 7, you may use the vapor deposition film of the material of copper, gold, aluminum, and molybdenum dihydride.

Embodiment 3

In the first embodiment, an example in which the friction reducing portion 7 is formed of a carbon deposited film having a particle diameter of 1 μm to a film thickness of 10 μm is shown. In the present embodiment, the particle size of carbon is changed within a range of 0.005 μm or more and 70 μm or less. The friction reducing portion 7 thus formed was formed, and the pressure-contacting rectifier was completed to investigate the failure occurrence rate regarding the operation time. The film thickness of the friction reducing part 7 was made 10 times the particle diameter. In the actual endurance test, in order to accelerate by 10 times, the applied voltage was made 10 times that of the normal test, and the failure occurrence rate after one year of operation was called the failure occurrence rate after 10 years.

4 is an explanatory diagram showing a relationship between a defective occurrence rate after 10 years of operation years and a particle size. In the range of the particle diameter of 0.01 micrometer or more and 50 micrometers or less, a defect incidence rate will be 10% or less, and it improves than the defective rate 12% in the absence of the friction reduction part 7. Moreover, in the range whose particle diameter is 0.05 micrometer or more and 20 micrometers or less, a defective rate will become 8% or less, and reliability improves further. Moreover, the defective rate becomes 6% or less in the range of 0.1 micrometer or more and 10 micrometers or less, and it becomes further more favorable.

When the particle diameter is smaller than 0.01 mu m, the friction reducing portion 7 can be made dense, which makes it difficult to move the particles for mitigating stress concentration due to friction, so that breakage of the diode chip 5 is likely to occur. When the rate of occurrence of poor defects increases and the particle size is larger than 50 μm, the contact due to the decrease in the contact area between the friction reducing portion 7 and the surfaces of the lid 2, the diode chip 5, and the case 4 is reduced. The resistance becomes high, the amount of heat generated during operation increases, the burnout of the diode chip 5 easily occurs, and the defective occurrence rate increases.

Embodiment 4

FIG. 5: is a schematic diagram which shows schematic structure of the pressure contact type rectification apparatus 10 in Embodiment 4. As shown in FIG. In FIG. 5, the lead 2 penetrates into the insulating cap 1 in which the external thread 1a was formed in the outer peripheral surface. The lead 2 is fixed by the insulating elastic body 3 which consists of silicone rubber, for example. The lower end of the lid 2 is a lead terminal 2a having a flat lower surface, and these are made of copper, for example. In order to fix the position of the diode chip 5 in a case 4 having a bottom portion with a female screw 4a that can be fitted with a cap 1 on an inner circumferential surface, a diode holder 6 cut out in the center is inserted. The diode chip 5 is arrange | positioned at the cut part. The case 4 is formed of, for example, copper having good electrical conductivity and thermal conductivity. The site | part which contacts the diode chip 5 of the inner surface of the bottom part of the case 4 is processed especially flat in order to enlarge the contact area with the diode chip 5. For example, the flatness is improved by pressing with a flat punch to cause plastic flow. The diode holder 6 is made of, for example, PPS (polyphenylene sulfide) resin having high insulation and high heat resistance. For example, plate-shaped silver is inserted between the lead terminal 2a and the diode chip 5 and between the case 4 and the diode chip 5 as the soft members 51a and 51b.

The upper and lower surfaces of the diode chip 5 serve as electrodes, and a carbon deposited film is formed on the surface of the diode chip 5 as the friction reducing portion 7. This carbon vapor deposition film is formed by resistance heating vapor deposition, and the film thickness is about 10 micrometers. By fitting the male screw 1a and the female screw 4a to fasten the cap 1 and the case 4, the diode chip 5 is connected to the lead terminal 2a and the case 4 via the elastic body 3. It is firmly contacted by pressure, and it becomes the pressure contact type rectifier 10.

In the pressure-contacting rectifier 10 configured as described above, when the diode chip 5 is firmly pressed into contact with the lead terminal 2a and the case 4, the soft members 51a and 51b are elastically deformed to lead the terminal. (2a) The minute unevenness | corrugation of the contact surface of the diode chip 5 and the holder case 4 can be embedded. As a result, the contact area between the diode chip 5 and the lead terminal 2a or the diode chip 5 and the case 4 can be increased, and the electrical conductivity and thermal conductivity can be improved.

Embodiment 5

FIG. 6 shows the pressure-contacting rectifying device 10 according to the fifth embodiment. In FIG. 6, the lead 2 penetrates the insulating cap 1 in which the external thread 1a was formed in the outer peripheral surface. The lead 2 is fixed by the insulating elastic body 3 which consists of silicone rubber, for example. The expansion and contraction portion 61 is provided outside the lid 2. The expansion and contraction portion 61 has the lead 2 as a U-shaped curved structure, for example. The lower end of the lid 2 is a lead terminal 2a having a flat lower surface, and these are made of copper, for example. In order to fix the position of the diode chip 5 in a case 4 having a bottom portion with a female screw 4a that can be fitted with a cap 1 on an inner circumferential surface, a diode holder 6 cut out in the center is inserted. The diode chip 5 is arrange | positioned at the cut part. The case 4 is formed of, for example, copper having good electrical conductivity and thermal conductivity. The site | part which contacts the diode chip 5 of the inner surface of the bottom part of the case 4 is processed especially flat in order to enlarge the contact area with the diode chip 5. For example, the flatness is improved by pressing with a flat punch to cause plastic flow. The diode holder 6 is made of, for example, PBT (polybutylene terephthalate) resin having high insulation and high heat resistance.

The upper and lower surfaces of the diode chip 5 serve as electrodes, and the carbon deposition film 7 is formed on the surface of the diode chip 5 as a friction reducing portion. This carbon vapor deposition film is formed by resistance heating vapor deposition, and the film thickness is about 10 micrometers. By fastening the cap 1 and the case 4 by fitting the male screw 1a and the female screw 4a, the diode chip 5 is connected to the lead terminal 2a and the case 4 via the elastic body 3. It is firmly pressurized to). Thereafter, the lid 2 is fixed to the cap 1 by an adhesive 62 having insulation. An epoxy resin etc. can be used as an adhesive agent, for example.

In the pressure-contacting rectifier 10 configured as described above, even if a force to be pulled upward is applied to the lid 2, the expansion and contraction portion 61 deforms and absorbs the force, and thus the lower portion of the component part below the cap 1 Position shift can be prevented. As a result, the reduction of the contact area between the lead terminal 2a and the diode chip 5 can be prevented, and a highly reliable pressurized contact rectifying device can be provided without increasing resistance or disconnection during energization.

Further, in the first to fifth embodiments described above, an example in which a male screw is formed on the outer circumferential surface of the cap and a female screw that can be fitted thereon is formed on the inner circumferential surface of the case. May be the opposite. Moreover, you may fit a cap and a case by other mechanisms, such as crimping | bonding other than a screw, for example.

In addition, in the said Embodiment 1 and Embodiment 2, although the friction reduction part showed the example formed by vapor deposition, you may form by other methods, such as forming by drying after apply | coating the suspension disperse | distributed to a solution in powder fine particles.

In addition, although the example which used plate-shaped silver as a soft member was shown in Embodiment 4, the material which is easy to deform | transform into electrical conductivity, for example, metals, such as copper and aluminum, and electroconductive rubber may be sufficient.

In addition, in the said Embodiment 5, although the extension part of the lead showed the example of the bending structure, you may use other elastic structures, such as a spring structure and a cylinder structure.

In the first to fifth embodiments described above, a diode chip is used as the rectifying element, but instead of the diode chip, a separate chip having the same electrical operation, for example, a rectifying element using an MOS-FET, etc. You may use.

As described above, the pressure-contacting rectifier according to the present invention is suitable for use in electrical parts and the like of automobiles operated with a large current.

Claims (7)

A rectifying element having a cap, a lead supported by an elastic body through the cap, a case fitable to the cap, an end portion of the lead and an electrode contacting the case, and provided on at least one side of the surface of the electrode. A friction reducing part, and the rectifying element is pressurized and fixed to the cap and the case, The friction reducing portion is conductive fine particles, The fine particles include at least one of carbon, silver, copper, gold, aluminum, molybdenum dihydride Pressurized contact rectifier. delete delete The method of claim 1, The particle size of the fine particles is characterized in that the 0.01㎛ 50㎛ Pressurized contact rectifier. The method of claim 1, A soft member is inserted into at least one of the contact portion between the rectifying element and the lead end, or the contact portion between the rectifying element and the case. Pressurized contact rectifier. The method of claim 1, An extension part is installed in a lead located outside the cap, and the lead is fixed to the cap. Pressurized contact rectifier. The method of claim 1, And a screw which can be fitted to an outer circumferential surface of the cap and an inner circumferential surface of the case, and is fastened by the screw to fix the rectifying element under pressure by the cap and the case. Pressurized contact rectifier.

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