JP2006332599A - Electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic device exhibiting high reliability in hermetic sealing in which an insulating substrate is not cracked even after the lid is welded to the insulating substrate by resistance welding and then cooled. <P>SOLUTION: The electronic device comprises an insulating substrate 1 having a recess 4 for containing an electronic component 5 in the upper surface, a metal frame 2 fixed to the upper surface of the insulating substrate 1, and a lid 3 for closing the recess 4 by bonding the outer circumferential portion of the lower surface to the upper surface of the metal frame 2 wherein the lid 3 has a bend 3b along a joint 3a to the metal frame 2 on the inside of the joint 3a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic device in which a concave portion of an insulating base in which an electronic component is accommodated is closed with a lid, and the electronic component is hermetically sealed.

  Conventionally, electronic parts such as piezoelectric vibrators and semiconductor elements are hermetically sealed in an insulating base for accommodating these electronic parts in an airtight manner to form an electronic device, which is used as a part of various electronic devices such as mobile phones and computers. used.

  Among the insulating bases for accommodating such electronic components in an airtight manner, the most reliable one is made of ceramics such as an aluminum oxide sintered body, and a recess for accommodating the electronic components in the central portion of the upper surface. An insulating base having a wiring shape that extends from the inside of the concave portion of the insulating base to the outer surface of the upper surface, such as the outer peripheral portion, the side surface, and the lower surface; The metallized layer and a metal frame made of a metal such as an iron-nickel-cobalt alloy or iron-nickel alloy brazed to the metallized layer are provided. Then, by joining a flat lid made of iron-nickel alloy or iron-nickel-cobalt alloy to the upper surface of the metal frame by resistance welding, the recess is closed and the electronic component is hermetically sealed.

In the case of the insulating base of this configuration, after storing the electronic component in the recess of the insulating base and electrically connecting the electrode of the electronic component and the wiring conductor, a flat lid is placed on the upper surface of the metal frame, The pair of roller electrodes of the resistance welding machine are rolled while contacting the outer periphery of the lid, and a large current for welding is passed between the pair of roller electrodes to directly connect the metal frame and the lid. By resistance welding, an electronic device as a product in which electronic components are hermetically housed is obtained. This electronic device is used by being mounted on an external electric circuit board by connecting a portion of the wiring conductor led to the outer surface of the insulating base to an external electric circuit.
JP 2000-151332 A JP 2000-134055 A

However, in the above conventional insulating base and electronic device,
Because it is heated to a high temperature of about 1000 ° C. during resistance welding, both the flat lid and the insulating base are expanded and sealed, and then a lid made of iron-nickel alloy or iron-nickel-cobalt alloy with cooling. Strong tensile stress (thermal stress) resulting from the difference in thermal expansion coefficient (linear expansion coefficient) between the body and the insulating base made of ceramics acts on the insulating base via the metal frame, and the metal frame is attached There was a problem that cracks occurred on the side surfaces of the insulating substrate. If a crack occurs in the insulating substrate, the reliability of the hermetic sealing of the electronic component deteriorates.

  In particular, with the recent downsizing of electronic devices, the thickness of the frame surrounding the concave portion of the insulating base tends to be thin and the mechanical strength tends to be low. Is becoming more likely to occur.

  The present invention has been completed in view of the above-described conventional problems. The object of the present invention is to join a lid body having a different thermal expansion coefficient and an insulating base by means such as welding, and to form an electron in the recess of the insulating base. In an electronic device in which components are hermetically sealed, an object of the present invention is to provide an electronic device excellent in the reliability of hermetic sealing without causing cracks in an insulating substrate.

An electronic device according to the present invention includes an insulating base having a recess for accommodating an electronic component on the upper surface, a metal frame attached to the upper surface of the insulating base, and an outer peripheral portion of the lower surface joined to the upper surface of the metal frame. And an electronic device comprising a lid that closes the recess,
The lid has a bent portion along the joint inside the joint with the metal frame.

  The electronic device of the present invention is preferably characterized in that the bent portion is provided in an annular shape when the lid is viewed in plan.

  In the electronic device of the present invention, it is preferable that the shape of the bent portion in plan view is a rectangular shape with rounded corners.

  In the electronic device according to the present invention, it is preferable that the upper surface and the lower surface of the lid body are arranged upward at the inner portion as compared with the outer portion of the bent portion.

  The electronic device of the present invention is preferably characterized in that the lid is joined to the metal frame by resistance welding.

  In the electronic device according to the present invention, preferably, the lid has a level difference between the inner portion and the outer portion of the bent portion, which is larger than the thickness of the lid member located on the joint portion. Is also large.

  The electronic device of the present invention is preferably characterized in that the lid body is thinner at the bent portion than at the joint portion with the metal frame.

  In the electronic device of the present invention, it is preferable that the bent portion has a curved shape with the lid projecting downward.

  In the electronic device of the present invention, it is preferable that the bent portion is on an extension line of the end portion of the electronic component from the joint portion of the lid body with the metal frame body when the electronic component is mounted. It is arrange | positioned between the site | parts which cross | intersect.

  Also, the electronic device of the present invention is preferably characterized in that a nickel plating layer is deposited on the joint surface of the lid with the metal frame.

  In the electronic device of the present invention, preferably, a nickel plating layer is deposited on the lower surface of the lid, and the nickel plating layer deposited on the joint is deposited on another portion. The melting point is lower than that of the layer.

According to the electronic device of the present invention, the insulating base having a recess for accommodating electronic components on the upper surface, the metal frame attached to the upper surface of the insulating base, and the outer peripheral portion of the lower surface are joined to the upper surface of the metal frame. And an electronic device comprising a lid that closes the recess,
Since the lid has a bent portion along the joint inside the joint with the metal frame, the tensile stress caused by the difference in thermal expansion coefficient between the lid and the insulating base is The bent portion is effectively absorbed by the bending. Therefore, it is possible to prevent a large tensile stress from acting on the metal frame and the insulating base, and it is possible to effectively prevent a problem that a crack occurs in the insulating base.

  Further, according to the electronic device of the present invention, the bent portion is provided in an annular shape in plan view of the lid body, which is caused by a difference in thermal expansion between the lid body and the insulating base when the lid body is joined. Tensile stress is distributed over the entire circumference of the lid in plan view, that is, the entire surface of the insulating substrate bonded to the upper surface, and cracks of the insulating substrate are further effectively prevented, resulting in more reliable electrons. Equipment can be provided.

  Further, according to the electronic device of the present invention, the planar view shape of the bent portion is due to the difference in thermal expansion between the lid body and the insulating base when the lid body is joined because the corner portion is a rounded rectangular shape. The stress is distributed along the outer edge of the rounded corner at and around the corner of the lid where the tensile stress is particularly likely to act. This effectively prevents the tensile stress from concentrating on one point (corner). A more reliable electronic device can be provided.

  Further, according to the electronic device of the present invention, the upper surface and the lower surface of the lid body are arranged upward at the inner portion as compared with the outer portion of the bent portion, so that the inside of the concave portion heated at the time of joining the lid body. Even if the temperature of the gas drops to room temperature and contracts, and the lid body is pushed by the outside atmospheric pressure and deformed so as to be slightly recessed toward the recessed portion, the lower surface of the lid body is an electronic component housed in the recessed portion, For example, touching a conductive part such as a thin metal wire connecting an electronic component to a wiring conductor formed on an insulating base, and inducing a problem such that these conductive parts cause an electrical short circuit through the lid. Can be effectively prevented and a more reliable electronic device can be provided.

  Moreover, according to the electronic device of the present invention, the lid body is joined to the metal frame body by resistance welding, so that an electronic device excellent in the reliability of hermetic sealing can be provided more reliably.

  Further, according to the electronic device of the present invention, the size of the step provided between the inner portion and the outer portion of the bent portion of the lid is larger than the thickness of the lid located on the joint portion. As a result, even if the temperature of the gas in the recesses heated at the time of joining of the lid body drops to normal temperature and contracts, and the lid body is pushed by the external atmospheric pressure and deformed to be slightly recessed toward the recess side, The lower surface of the body touches a conductive portion such as an electronic component housed in the recess, or a thin metal wire that connects the electronic component to a wiring conductor formed on the insulating base, and the conductive portions are connected to each other via the lid. Inducing a malfunction such as an electrical short circuit is effectively prevented, and an electronic device with higher reliability can be provided.

  Further, according to the electronic device of the present invention, the thickness of the lid is thinner at the bent portion than at the joint with the metal frame, so that the mechanical strength of the joint with the metal frame is required. The lid can be made sufficiently thick to ensure the bonding strength, and the bending stress that is relatively thin and easily bent can absorb the tensile stress more effectively. Therefore, the problem that cracks are generated in the insulating substrate to which the metal frame is attached can be prevented more effectively.

  Further, according to the electronic device of the present invention, the bent portion 3b is formed by bending the lid 3 in a U-shape on the lower side, so that the metal of the lid or the metal frame is accompanied by resistance welding. Even if the component melts and scatters, the scattered matter adheres to the side surface of the U-shaped bent portion on the frame body side, so that entry into the recess is suppressed. Therefore, it is possible to provide a more reliable electronic device that effectively prevents the scattered matter from adhering to the electronic component and inducing malfunctions such as malfunctions and electrical shorts.

  Even when the bent portion has a curved shape with the lid projecting downward, the tensile stress resulting from the difference in thermal expansion coefficient between the lid and the insulating base is effectively absorbed by the bending portion being bent. The problem of cracking in the insulating substrate can be effectively prevented.

  According to the electronic device of the present invention, when the electronic part is mounted, the bent portion is joined to the metal frame of the lid body in a longitudinal sectional view (a longitudinal section orthogonal to the insulating base body 1, hereinafter agreed). Between the joint and the part that intersects the extension line of the end of the electronic component, the bent portion is located between the joint and the electronic component, and the molten scattered matter scatters to the electronic component. Can be prevented more effectively, and a more reliable electronic device can be provided.

  In addition, according to the electronic device of the present invention, since the nickel plating layer is deposited on the joint surface of the lid with the metal frame, the nickel plating is applied at the time of welding resistance for joining the lid and the metal frame. The layers melt and can be joined easily. Since the nickel plating layer has a melting point as low as about 800 to 1000 ° C. as compared with an iron-nickel alloy or iron-nickel-cobalt alloy (melting point, 1449 ° C.), it can be welded at a low temperature. For this reason, defects such as mechanical damage to the insulating substrate where the thermal stress is generated between the insulating substrate and the metal frame due to heat during resistance welding and the metal frame is peeled off are suppressed, and more reliable electrons Equipment can be provided.

  Further, according to the electronic device of the present invention, the nickel plating layer is deposited on the lower surface of the lid, and the nickel plating layer deposited on the joint is more than the nickel plating layer deposited on the other portion. However, since the melting point is low, it is possible to weld resistance so that only the nickel plating of the joint of the lid melts and the nickel plating of other parts does not melt when welding resistance to join the lid to the metal frame. It is possible to provide a more reliable electronic device in which the nickel plating of other portions is not melted and scattered in the electronic component.

  In addition, since the nickel plating layer is deposited on the lower surface of the lid, the electric resistance on the lower surface side of the lid is lowered, current flows easily, and resistance welding can be performed more easily and reliably.

  In addition, in a longitudinal cross-sectional view orthogonal to the insulating base, the side surface of the bent portion located below the joint portion of the lid body and the frame body, in particular, the side surface on the frame body side is coated with the nickel plating layer, Scattered matter (mainly nickel having a low melting point deposited on the joint) adheres more easily and firmly. Therefore, the reliability of the electronic device is improved.

  The electronic device of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a sectional view showing an example of an embodiment of an electronic device 9 of the present invention.

  In FIG. 1, 1 is an insulating substrate, 2 is a metal frame, and 3 is a lid.

  The electronic device 5 is basically configured by housing the electronic component 5 in the concave portion 4 on the upper surface of the insulating base 1 and joining the lid 3 to the upper surface of the metal frame 2 to hermetically seal the electronic component 5. The

  The insulating substrate 1 has, for example, a rectangular parallelepiped shape and is provided with a concave portion 4 on which an electronic component 5 is mounted on the upper surface, such as an aluminum oxide sintered body, a glass ceramic, an aluminum nitride sintered body, and a mullite sintered body. It is formed of an insulating material. When the insulating substrate 1 is made of, for example, an aluminum oxide sintered body, an appropriate organic binder and solvent are added to and mixed with raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide to form a slurry. A plurality of ceramic green sheets for the insulating substrate 1 are produced by forming into a sheet shape by a conventionally known doctor blade method, and then a suitable punching process is performed on a part of the ceramic green sheet to form a frame shape. The frame-shaped ceramic green sheets are stacked one above the other so that they are positioned in the upper layer, and are fired at a high temperature of about 1600 ° C.

  The electronic component 5 mounted in the recess 4 is an optical semiconductor such as a semiconductor integrated circuit element such as an IC or LSI, an LD (semiconductor laser), an LED (light emitting diode), a PD (photodiode), a CCD, a line sensor, or an image sensor. These are elements, piezoelectric vibrators, vibrators such as crystal vibrators, and other various electronic components.

  In the insulating base 1, the wiring conductor 6 is led out from the inner side of the recess 4 to the outer surface (the outer peripheral portion of the upper surface, the side surface, the lower surface, etc.).

  The wiring conductor 6 functions as a conductive path that leads the electronic component 5 accommodated in the recess 4 to the outer surface of the insulating base. An electrode (not shown) of the electronic component 5 accommodated in the recess 4 is electrically connected to a portion of the wiring conductor 6 exposed to the recess 4 via a bonding wire (metal thin wire) 8 or solder (not shown). By connecting to, the electrode of the electronic component 5 is led out to the outer surface of the insulating substrate 1 through the wiring conductor 6.

  The wiring conductor 6 is made of a metal material such as tungsten, molybdenum, manganese, copper, silver, or gold. For example, when it is made of tungsten, the tungsten paste obtained by adding and mixing an appropriate organic binder and solvent to tungsten powder is insulated. The ceramic green sheet to be the base 1 is printed and applied in a predetermined pattern by a well-known screen printing method, and is fired together with the ceramic green sheet to be the insulating base 1 to form a predetermined pattern.

  The means for leading the electrode of the electronic component 5 to the outside of the recess (the outer surface of the insulating base 1) is not limited to the wiring conductor 6, and may be a means such as a metal terminal or a via conductor. You may use together.

  The insulating base 1 has a frame-like metallized layer 7 formed on the upper surface so as to surround the recess 4. A metal frame 2 made of a metal material such as iron-nickel-cobalt alloy is brazed and joined to the metallized layer 7 via a brazing material (not shown) such as silver brazing.

  Also, the lid 4 made of a metal material such as iron-nickel alloy or iron-nickel-cobalt alloy is joined to the metal frame 2 by joining means such as resistance welding, electron beam welding, brazing, etc. Is closed with the lid 3, and the electronic component 5 is hermetically sealed inside the container formed of the insulating base 1, the metal frame 2, and the lid 3.

  The metallized layer 7 functions as a base metal layer for brazing the metal frame 2 and can be formed of the same metal material as the wiring conductor 6. When the metallized layer 7 is made of tungsten, for example, a tungsten paste obtained by adding and mixing an appropriate organic binder and solvent to the tungsten powder is used to surround a portion surrounding the concave portion 4 of the ceramic green sheet serving as the insulating base 1, that is, the uppermost layer. It is formed by printing and applying a frame-shaped pattern on the upper surface of the frame-shaped ceramic green sheet.

  Further, when the metal frame 2 is made of, for example, an iron-nickel-cobalt alloy, the metal frame 2 is formed by subjecting a plate material of the iron-nickel-cobalt alloy to suitable rolling, punching, etching, or the like.

  The shape of the metal frame 2 is, for example, a rectangular frame shape with a rectangular inner periphery. As a result, the electronic component 7 that is generally a rectangular parallelepiped, such as a semiconductor integrated circuit element or a piezoelectric vibrator, can be efficiently surrounded without taking a useless space. In this case, it is preferable that the metal frame 2 prevent each corner from being chamfered in an arc shape to cause chipping or the like at the corner.

  Also, the brazing of the metal frame 4 to the metallized layer 7 is performed by interposing a brazing material such as silver brazing (preform of brazing material) between the metallized layer 7 and the lower surface of the metal frame 4. It is carried out by melting and joining the materials.

  Then, the electronic component 5 is mounted in the concave portion 4 of the insulating base 1 and the electrode is electrically connected to the wiring conductor 6. Thereafter, the lid 3 is attached to the upper surface of the metal frame 2 by resistance welding, electron beam welding, brazing, or the like. The electronic device 9 is configured by hermetically sealing the electronic component 5 by joining with a joining means such as attaching.

  Since the lid 3 is joined to the metal frame 2 by the joining means as described above, the lid 3 is formed of a metal material such as an iron-nickel-cobalt alloy or an iron-nickel alloy.

  The lid 3 is formed in a plan view shape suitable for closing the recess 4. For example, when the recessed part 4 is formed in the rectangular shape suitable for accommodation of a rectangular parallelepiped electronic component, the cover body 3 is formed in a rectangular shape in plan view.

  Moreover, it is preferable that the cover body 3 is formed so that the outer peripheral edge is located inside the outer peripheral edge of the metal frame 2. In this case, a weld metal or braze fillet is formed on the outer side of the joint between the metal frame 2 and the lid 2 so that the joint can be made stronger.

  In the electronic device 9 of the present invention, as shown in FIG. 1, the lid 3 has a bent portion 3 b along the joint portion 3 a on the inner side of the joint portion 3 a with the metal frame 2.

  With this configuration, the lid 3 is joined to the upper surface of the metal frame 2 by, for example, resistance welding, and the electronic component 5 is hermetically sealed, and is heated to a high temperature of about 1000 ° C. during resistance welding, and then cooled. Along with this, the tensile stress resulting from the difference in thermal expansion coefficient between the lid 3 and the insulating base 1 is effectively absorbed by the bending portion 3b being bent. Therefore, it is possible to prevent a large tensile stress from acting on the metal frame 2 and the insulating base, and it is possible to effectively prevent the problem that the insulating base 1 is cracked.

  The lid 3 having the bent portion 3b is formed into a predetermined size by subjecting a plate material of, for example, an iron-nickel-cobalt alloy to a cutting process such as punching, and a bent portion by bending a part thereof by a press working method. Can be manufactured.

  In order to effectively absorb the tensile stress generated between the lid 3 and the insulating base 1, the bent portion 3b is a portion of the joint between the lid 3 and the metal frame 2 that is a starting point of stress. It is necessary to form inside along the joint.

  The bent portion 3b is directed toward the side opposite to the concave portion 4 (upper side) in order to prevent a problem in which the electrodes adjacent to the electronic component 5 and the fine metal wires 8 are brought into electrical short circuit. A bent shape.

  Further, the form of bending is not limited to one stage as shown in the figure, and may be bent in a plurality of stages. Further, the surface of the bent portion 3b may be curved.

  Moreover, it is preferable that the bending part 3b is located in the site | part close | similar to the junction part of the cover body 3 and the metal frame 2, when absorbing tensile stress. However, if the bent portion 3b is too close to the joint portion, it is difficult to align the bent portion 3b so that it does not overlap the joint portion when the lid body 3 is joined. The reliability of hermetic sealing may be lowered. Therefore, the bent portion 3 b is preferably at a position where the inner portion thereof is in contact with the outer peripheral portion of the electronic component 5 in plan view.

  As shown in FIG. 2, in the electronic device 9 of the present invention, the bent portion 3 b is preferably provided in an annular shape when the lid 3 is viewed in plan. In this case, the tensile stress due to the thermal expansion difference between the lid 3 and the insulating base 1 is dispersed over the entire circumference of the lid 3 in plan view, that is, over the entire insulating base 1 where the lid 3 is joined to the upper surface, Cracks in the insulating substrate 1 are further effectively prevented, and a more reliable electronic device 9 can be provided. 2 is a top view of the electronic device shown in FIG. In FIG. 2, the same parts as those in FIG.

  Moreover, in the electronic device 9 of the present invention, the planar view shape of the bent portion 3b is preferably a rectangular shape with rounded corners. In this case, when the lid 3 is joined, the stress along the outer edge of the round is formed at and around the corner of the lid 3 where the tensile stress caused by the difference in thermal expansion between the lid 3 and the insulating base 1 is particularly large. Therefore, it is possible to effectively prevent the tensile stress from concentrating on one point (corner) and to provide the electronic device 9 with higher reliability.

  The roundness is, for example, an arc shape having the outer edge of the bent portion 3b as a tangent when the lid 3 is rectangular in plan view.

  Furthermore, in the electronic device 9 of the present invention, it is preferable that the upper surface and the lower surface of the lid body 3 are arranged upward at the inner portion as compared with the outer portion of the bent portion 3b. With this configuration, it is assumed that the temperature of the gas in the recess 4 heated when the lid is joined is lowered to normal temperature and contracts, and the lid 3 is pushed by the outside atmospheric pressure and deformed so as to be slightly recessed toward the recess. In addition, the lower surface of the lid touches the conductive part such as the electronic component 5 housed in the recess 4 or the fine metal wire 8 that connects the electronic component to the wiring conductor 6 formed on the insulating base 1, for example. Thus, it is possible to effectively prevent an inconvenience such that an electrical short circuit occurs between these conductive parts, and the electronic device 9 having higher reliability can be provided.

  Furthermore, in the electronic device 9 of the present invention, the lid 3 is preferably joined to the metal frame 2 by resistance welding. With this configuration, it is possible to more reliably provide the electronic device 9 having excellent hermetic sealing reliability.

  When the lid 3 is joined to the metal frame 2 by resistance welding, a metal layer having a melting point lower than that of the lid, such as nickel, is plated on at least a portion of the surface of the lid that is joined to the metal frame 2 For example, the resistance welding may be performed more easily.

  Furthermore, in the electronic device 9 according to the present invention, the lid 3 has a level difference between the inner portion and the outer portion of the bent portion 3b that is larger than the thickness of the lid 3 located on the joint portion 3a. Is also preferably large. With this configuration, the temperature of the gas in the recess 4 heated during the bonding of the lid body 3 drops to normal temperature and contracts, and the lid body 3 is pushed by the outside atmospheric pressure and deformed to be slightly recessed toward the recess side. Even so, the lower surface of the lid 3 touches the conductive part such as the electronic component 5 housed in the recess 4 or, for example, the metal thin wire 8 that connects the electronic component 5 to the wiring conductor 6 formed on the insulating base 1, It is possible to effectively prevent such a problem that the conductive parts cause an electrical short circuit through the lid, and the electronic device 9 with higher reliability can be provided.

  That is, the thickness of the lid 3 is preferably about 0.1 mm in consideration of securing the bonding strength by resistance welding, for example, and in this case, the size of the step is preferably about 0.15 mm to 0.4 mm.

  Furthermore, in the electronic device 9 of the present invention, it is preferable that the thickness of the lid 3 is thinner at the bent portion 2b than the joint 2a with the metal frame 2. With this configuration, the lid 3 can be made sufficiently thick at portions where mechanical strength for joining with the metal frame 2 is required to ensure the joining strength, and the bending portion is relatively thin and easily bent. In 3b, the tensile stress can be absorbed more effectively. Therefore, the problem that cracks occur in the insulating substrate 1 to which the metal frame 2 is attached can be more effectively prevented.

  That is, when the thickness of the lid 3 is 0.1 mm, the thickness of the bent portion 2b is preferably about 0.08 mm. This can be obtained by a method in which the gap in the portion in contact with the bent portion 2b of the press mold for processing the lid 3 is made narrower than the gap in other portions.

  An example of another embodiment of the electronic device of the present invention is shown in FIG.

  FIG. 3 is a cross-sectional view showing another embodiment of the electronic device 9 of the present invention, and the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals.

  In the electronic device 9, the bent portion 3b has a shape in which the lid body 3 protrudes downward and is curved. Other parts are the same as those described with reference to FIGS. 1 and 2.

  By forming the bent portion 3b having a curved shape with the lid 3 protruding downward, even if resistance welding, the metal components of the lid 3 and the metal frame 2 are melted and scattered, Since the scattered matter adheres to the side surface of the bent portion 3b on the frame body side, entry into the concave portion 4 is suppressed. Therefore, it is possible to provide a highly reliable electronic device 9 that effectively prevents scattered objects (such as scattered metal) from adhering to the electronic component 5 to induce malfunctions such as malfunctions and electrical shorts. it can.

  Even when the bent portion 3b has a curved shape in which the lid 3 protrudes downward, the bent portion 3b bends due to the tensile stress caused by the difference in thermal expansion coefficient between the lid 3 and the insulating base 1. Therefore, the problem of cracks occurring in the insulating substrate 1 can be effectively prevented.

  Thus, in order to produce the bent portion 3b having a curved shape by protruding the lid 3 downward, the lid 3 is partially bent by performing a mechanical bending process or a pressing process. Such a method can be used.

  In addition, the bending part 3b can prevent more reliably prevention of the adhering to the electronic component 5 of a scattered matter by arrange | positioning in the frame shape and cyclic | annular form which surround the electronic component 5 by planar view.

  In addition, the bent portion 3b may be a protruding and curved shape such as a U-shape or a V-shape in a longitudinal sectional view, and according to the shape and accuracy of the apparatus used for processing, As long as the effect is not impaired, the side surface may be inclined or curved. Further, the shape of both side surfaces sandwiching the tip may be different.

  Further, in the electronic device 9 of the present invention, when the electronic component 5 is mounted, the bent portion 3b is an extension of the end of the electronic component 5 from the joint portion of the lid 3 with the metal frame 2 in a longitudinal sectional view. Since it is arrange | positioned between the site | parts which cross | intersect on a line | wire, the bending part 3b is located between a junction part and the electronic component 5, and it prevents the molten metal plating to the electronic component 5 more effectively. In addition, the electronic device 9 with higher reliability can be provided.

  Further, in the electronic device 9 of the present invention, since the nickel plating layer (not shown) is attached to the joint surface (not indicated) of the lid 3 with the metal frame 2, the lid 3 and the metal At the time of welding resistance for joining the frame body 2, the nickel plating is melted and joining can be performed easily. Since the nickel plating layer has a melting point as low as about 800 to 1000 ° C. as compared with an iron-nickel alloy or iron-nickel-cobalt alloy (melting point, 1449 ° C.), it can be welded at a low temperature. Therefore, a heat stress is generated between the insulating base 1 and the metal frame 2 due to heat at the time of resistance welding, and problems such as peeling of the metal frame 2 and mechanical breakdown of the insulating base 1 are suppressed. The electronic device 9 with higher reliability can be provided.

  The nickel plating layer can be applied to the joint surface of the lid 3 with the metal frame 2 by a plating method such as an electroless plating method or an electrolytic plating method.

  For example, in the case of the electroless plating method, the lid 3 (brazing) is applied to an electroless nickel plating solution containing a nickel source such as nickel sulfate and a phosphorus-based reducing agent such as hypophosphorous acid as main components. Can be deposited by dipping. In this case, since the nickel plating layer contains about 3 to 10% by mass of phosphorus because the components of the reducing agent are eutectoid, the melting point is lowered to about 800 ° C. by the action of the eutectoid components.

  Moreover, in the electronic device 9 of the present invention, the nickel plating layer is applied to the lower surface of the lid 3, and the nickel plating layer applied to the joint portion is applied to the other portion. Since the melting point is lower than the above, at the time of welding resistance for joining the lid 3 and the metal frame 2, only the nickel plating at the joining portion of the lid 3 is melted and the nickel plating at other portions is not melted. It is possible to provide a highly reliable electronic device 9 that can be resisted and that the nickel plating of other portions is not melted and scattered in the electronic component 5.

  In addition, since the nickel plating layer is deposited on the lower surface of the lid 3, the electric resistance on the lower surface side is lowered, current flows easily, and resistance welding can be performed more easily and reliably.

  In addition, a nickel plating layer is applied to the side surface of the bent portion 3b, particularly the side surface on the frame body side, located below the joint between the lid body and the frame body in a longitudinal sectional view orthogonal to the insulating substrate. The scattered matter (mainly nickel having a low melting point deposited on the joint) adheres more easily and firmly. Therefore, the reliability of the electronic device 9 is improved.

  In order to deposit the nickel plating layer on the lower surface of the lid 3 so that the nickel plating layer deposited on the joining portion has a lower melting point than the nickel plating layer deposited on other portions, for example, The following method is used.

  First, a nickel plating layer is formed on the entire surface of the lid 3 (before brazing) using an electroless nickel plating solution mainly composed of a nickel source such as nickel sulfate and a boron-based reducing agent such as dimethylamine borane. Adhere. Next, a mask material such as a resin material is applied to the exposed surface (particularly the lower surface) of the lid 3 excluding the joint surface (part to be the joint surface) for masking. It is immersed in an electroless nickel plating solution containing an agent, and a nickel plating layer containing phosphorus is deposited on the joint surface. Since the nickel plating layer deposited by the electroless nickel plating solution containing a boron-based reducing agent does not co-deposit with much phosphorus component, the melting point is as high as about 1000 ° C. Through the above-described steps, a nickel plating layer having a melting point lower than that of the portion to be deposited on the joining portion is deposited and formed.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. For example, the insulating substrate 1 may have a flat plate shape, or may have a metal frame 2 joined to a flat upper surface and a concave portion 4 for storing an electronic component.

  Further, the exposed surfaces of the wiring conductor 6, the metal frame 2 and the lid 3 are covered with a plating layer of nickel, gold or the like to prevent oxidative corrosion and to make the bonding of the fine metal wires 8 more reliable and strong. Also good.

It is sectional drawing which shows an example of embodiment of the electronic device of this invention. It is a top view of the electronic device shown in FIG. It is sectional drawing which shows other embodiment of the electronic device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Insulation base | substrate 2 ... Metal frame 3 ... Lid 3a ... Connection part 3b ... Bending part 4 ... Concave part 5 ... Electronic component 6 ... Wiring conductor 7 ... Metallized layer 8 ... Metal wire 9 ... Electronic device

Claims (11)

An insulating base having a recess for receiving an electronic component on the upper surface, a metal frame attached to the upper surface of the insulating base, and a lid for closing the recess by joining the outer peripheral portion of the lower surface to the upper surface of the metal frame An electronic device comprising: a body, wherein the lid body has a bent portion along the joint inside the joint with the metal frame. The electronic device according to claim 1, wherein the bent portion is provided in an annular shape when the lid is viewed in plan. The electronic device according to claim 2, wherein a shape of the bent portion in plan view is a rectangular shape with rounded corners. 4. The electronic device according to claim 1, wherein an upper surface and a lower surface of the lid body are disposed upward at an inner portion as compared with an outer portion of the bent portion. 5. The electronic device according to claim 1, wherein the lid is joined to the metal frame by resistance welding. 2. The lid according to claim 1, wherein a size of a step provided between an inner part and an outer part of the bent part is larger than a thickness of the lid located on the joint part. The electronic device according to claim 1. 7. The electronic device according to claim 1, wherein a thickness of the lid body is thinner at the bent portion than a joint portion with the metal frame. The electronic device according to claim 1, wherein the bent portion has a curved shape with the lid projecting downward. When the electronic component is mounted, the bent portion is arranged between a portion of the lid body that intersects the extended line of the end portion of the electronic component from a joint portion of the lid body with the metal frame body in a longitudinal sectional view. The electronic device according to claim 8. 10. The electronic device according to claim 8, wherein a nickel plating layer is attached to a joint surface between the lid and the metal frame. A nickel plating layer is applied to the lower surface of the lid, and the nickel plating layer applied to the joint has a melting point lower than that of the nickel plating layer applied to other portions. The electronic device according to claim 10.

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