JP3393784B2 - Electronic component storage package - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component housing package for housing electronic components such as optical semiconductor elements and piezoelectric vibrators. 2. Description of the Related Art Conventionally, electronic component housing packages for housing electronic components such as optical semiconductor elements and piezoelectric vibrators have been known.
As shown in the cross-sectional view of FIG. 2, it is made of an electrically insulating material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a silicon carbide sintered body, and a glass ceramic sintered body. A substantially disk-shaped or square-plate-shaped insulating base 11 having a mounting portion 11a for mounting an electronic component at the center of the upper surface thereof and a metallized wiring layer 12 extending from the upper surface to the lower surface of the mounting portion 11a; External lead terminals 13 attached to a metallized wiring layer 12 led out to the lower surface of 11 via a brazing material such as silver brazing, and attached to the outer peripheral edge of the upper surface of the insulating base 11 via a brazing material such as silver brazing. A flat annular flange member having an outer peripheral portion 14a protruding outside the insulating base 11 over the entire periphery in the horizontal direction from the outer peripheral edge of the insulating base 11
14 and a flange portion having substantially the same outer peripheral dimensions as the flange member 14 at the lower end portion
And a metal cap 15 having an upper surface 15a.
16 is bonded and fixed via an adhesive such as brazing material, glass, resin, etc., and the electrodes of the electronic component 16 are bonded to bonding wires 17.
And electrically connected to the metallized wiring layer 12 through the outer peripheral portion 14 of the flange member 14 attached to the insulating base 11.
By welding a flange portion 15a of the metal cap 15 to a, and hermetically sealing the electronic component 16 inside a container mainly composed of the insulating base 11 and the metal cap 15, an electronic device as a product is obtained. [0003] In addition, the flange member 14 attached to the insulating base 11 and the metal cap 15 are welded by pressing the outer peripheral portion 14a of the flange member 14 and the outer peripheral portion of the flange portion 15a of the metal cap 15 with each other. A large current is applied between the member 14 and the metal cap 15, thereby generating Joule heat at a contact portion between the flange member 14 and the metal cap 15,
This Joule heat is used to melt the vicinity of the contact portion between the outer peripheral portion 14a of the flange member 14 and the flange portion 15a of the metal cap 15. In this conventional package for storing electronic components, even when an external force is applied to the outer peripheral portion 14a of the flange member 14 when the package is handled, the outer peripheral portion 14a is easily deformed by the external force. In order to prevent the good welding of the flange member 14 and the metal cap 15 from being impossible, the thickness of the flange member 14 is usually set to be about 0.2 mm or more. [0005] However, in this conventional package for storing electronic parts, the thickness of the flange member 14 is as large as about 0.2 mm or more. When the outer peripheral dimension of the member is reduced, the outer peripheral portion 14a is
When the protrusion width protruding from the flange 11 is less than about 0.5 mm, the outer peripheral portion 14a of the flange member 14 becomes difficult to bend. When the thermal stress is applied, most of the stress is applied to the joint between the insulating base 11 and the flange member 14 without being absorbed by the flange member 14, and the flange member 14 is peeled from the insulating base 11. Or the cracks occur in the insulating base 11, causing a drawback that the airtightness of the container is broken. The present invention has been made in view of the above circumstances, and an object of the present invention is to cause peeling of a flange member and cracking of an insulating base during welding even when the outer peripheral dimension of the flange member is reduced. It is an object of the present invention to provide a small and highly airtight electronic component storage package that does not need to be mounted. A package for storing electronic components according to the present invention has an insulating base having a mounting portion on which an electronic component is mounted on an upper surface, and an outer peripheral portion attached to an outer peripheral edge of the insulating base. A metal member having a flat annular member having a flat portion whose outer periphery is substantially the same as that of the flange member at the lower end, the flange being joined to the flange member by welding while being pressed against the flange member; In the electronic component storage package including the cap, the outer peripheral portion of the flange member is thicker than the inner peripheral thickness of the outer peripheral portion. According to the electronic component housing package of the present invention, the thickness of the flange member to which the metal cap is welded is greater on the outer peripheral side of the outer peripheral part than on the inner peripheral side. Even if it acts on the flange member, the stress is favorably absorbed and alleviated by bending the thin portion inside the outer peripheral portion of the flange member, and the thickness of the outer peripheral portion of the outer peripheral portion is large, so that the mechanical force of the flange member is increased. The target strength is maintained. Therefore, a small and airtight electronic component storage package free of peeling of the flange member and cracking of the insulating base during welding can be obtained. Next, the present invention will be described with reference to the accompanying drawings. FIG. 1 is a sectional view showing an example of an embodiment in which the electronic component housing package of the present invention is applied to an electronic component housing package for housing an optical semiconductor element. In FIG. 1, reference numeral 1 denotes an insulating base, and 2 denotes a metal cap. The insulating base 1 and the metal cap 2 mainly constitute a container 3 in which an electronic component (optical semiconductor element) 4 is hermetically accommodated. A mounting portion 1a for mounting the optical semiconductor element 4 is provided at the center of the upper surface of the insulating base 1. On the upper surface of the mounting portion 1a, the optical semiconductor element 4 is provided with a conductive brazing material or resin. It is bonded and fixed via an adhesive such as glass. The insulating substrate 1 is a substantially disc made of an electrically insulating material such as a sintered body of aluminum oxide, a sintered body of aluminum nitride, a sintered body of mullite, a sintered body of silicon carbide, and a sintered body of glass ceramic. For example, in the case of an aluminum oxide sintered body, an appropriate binder or solvent is added to and mixed with raw material powders of aluminum oxide, silicon oxide, calcium oxide, magnesium oxide, etc. to form a slurry. Along with this, a plurality of ceramic green sheets are obtained by adopting a conventionally known doctor blade method or the like into a sheet shape, and thereafter, each of these ceramic green sheets is subjected to an appropriate punching process and these are vertically It is manufactured by laminating and firing at a high temperature (about 1600 ° C.). A plurality of metallized wirings 5 are formed on the insulating substrate 1 from the upper surface to the lower surface of the mounting portion 1a. The electrodes are electrically connected via a conductive adhesive and a bonding wire 6,
On the other hand, a pin-shaped external lead terminal 7 connected to an external electric circuit board is attached to a portion led out to the lower surface of the insulating base 1 via a brazing material such as silver brazing. The metallized wiring 5 is made of a metal powder sintered body such as tungsten or molybdenum / molybdenum-manganese / copper / silver / silver / palladium. The metal paste obtained by mixing is preliminarily printed and applied in a predetermined pattern on a ceramic green sheet serving as the insulating substrate 1 by a conventionally known screen printing method, and is fired simultaneously with the ceramic green sheet to thereby mount the mounting portion 1a of the insulating substrate 1. It is formed from the upper surface to the lower surface. The metallized wiring 5 is usually used to effectively prevent the metallized wiring 5 from being oxidized and corroded, and to improve the connectivity between the metallized wiring 5 and the conductive adhesive and the bonding wire 6. On the exposed surface, a nickel plating layer and a gold plating layer are sequentially applied. The insulating base 1 has an annular metallized metal layer 8 formed on the outer peripheral edge of the upper surface thereof, and a flange member 9 is attached to the metallized metal layer 8 via a brazing material such as silver solder. Have been. The annular metallized metal layer 8 is made of a sintered metal powder such as tungsten or molybdenum / molybdenum-manganese / copper / silver / silver / palladium.
Acts as a base metal for bonding the flange member 9 to the base member. For example, when it is made of tungsten, a metal paste obtained by adding and mixing an appropriate binder and a solvent to tungsten powder is printed in a predetermined pattern on a ceramic green sheet serving as the insulating substrate 1, and is fired simultaneously with the ceramic green sheet. Thus, the insulating substrate 1 is annularly attached to the outer peripheral edge of the upper surface. The annular metallized metal layer 8 is electrically connected to a part of the metallized wiring layer 5 if necessary, and its surface is usually provided with a brazing material such as a nickel plating layer or a gold plating layer. A plated metal layer having excellent wettability and excellent corrosion resistance. The flange member 9 brazed to the metallized metal layer 8 is made of a metal such as an iron-nickel alloy or an iron-nickel-cobalt alloy. Is a flat plate-shaped annular body having an outer peripheral portion 9a protruding outside the insulating base over the outer peripheral portion 9a.
The thickness on the inner peripheral side of a is as small as about 0.1 mm, and the thickness on the outer peripheral side of the outer peripheral portion 9a is as large as about 0.2 mm, for example. The flange member 9 functions as a joint for joining the metal cap 2 to the insulating base 1. The metal cap 2 is joined to the outer peripheral portion 9a by welding. Here, since the thickness of the flange member 9 is thin on the inner peripheral side of the outer peripheral portion 9a, when the metal cap 2 is welded to the outer peripheral portion 9a, thermal stress caused by welding heat is applied to the outer peripheral portion 9a.
Even if the stress acts on the insulating substrate 1, the stress is favorably absorbed and relaxed by bending the inner peripheral side where the outer peripheral portion 9 a is thin, and as a result, the flange member 9 is peeled from the insulating substrate 1 or a crack is generated in the insulating substrate 1. Is effectively prevented. The width of the thin portion on the inner peripheral side of the outer peripheral portion 9a of the flange member 9 is 2.5 times the thickness of the portion.
If it is less than twice, the inner peripheral side of the outer peripheral portion 9a is less likely to bend, and it is difficult to satisfactorily absorb and relax by bending the stress due to welding heat when welding the metal cap 2 to the outer peripheral portion 9a. Tend to be. Therefore, it is preferable that the width of the thin portion of the flange member 9 on the inner peripheral side of the outer peripheral portion 9a is 2.5 times or more the thickness of the portion. Further, since the flange member 9 has a large thickness on the outer peripheral side of the outer peripheral portion 9a, the mechanical strength of the outer peripheral portion 9a is maintained on the outer peripheral side where the thickness is large. As a result, when the package is handled, Even when an external force is applied to the outer peripheral portion 9a of the flange member 9, the outer peripheral portion 9a is not easily deformed by the external force. Therefore, when the flange member 9 and the metal cap 2 are joined by welding, the flange member 9 9 and the metal cap 2 can be satisfactorily welded. If the thickness of the thick portion on the outer peripheral side of the outer peripheral portion 9a is less than 0.2 mm, the outer peripheral portion 9a tends to be easily deformed when an external force is applied to the outer peripheral portion 9a. is there. Therefore, it is preferable that the thickness of the flange member 9 on the outer peripheral side of the outer peripheral portion 9a is 0.2 mm or more. The flange member 9 is attached to the insulating base 1 by, for example, forming a brazing material such as silver brazing on the metallized metal layer 8 attached to the upper surface of the insulating base 1 in an annular shape. The reform and the flange member 9 are sequentially placed, and thereafter, the brazing filler metal preform is attached by heating and melting to the metallized metal layer 8 and attached to the outer peripheral edge of the insulating base 1. The metal cap 2 to be welded to the flange member 9 is made of a metal such as an iron-nickel alloy or an iron-nickel-cobalt alloy.
A silk hat-shaped container member having a flange portion 2a having substantially the same outer peripheral dimension as that of the above and a window member 2b made of a translucent material such as glass at an upper end portion, and a space for accommodating the optical semiconductor element 4 therein. Is formed, and the flange portion 2a is welded to the flange member 9 attached to the insulating base 1, so that the optical semiconductor element 4 is hermetically sealed inside the container 3 mainly composed of the insulating base 1 and the metal cap 2. The optical signal can be transmitted and received between the optical semiconductor element 4 and the outside through the window member 9b. The welding of the metal cap 2 to the flange member 9 is performed by pressing the outer peripheral portion 9a of the flange member 9 and the outer peripheral portion of the flange portion 2a of the metal cap 2 against each other while pressing the outer peripheral portion 9a of the flange member 9 against the metal. A large current is applied between the flange member 9 and the metal cap 2.
This is performed by generating Joule heat at the contact portion with the flange member 9 and melting the vicinity of the contact portion between the flange member 9 and the metal cap 2 by the Joule heat. Thus, according to the electronic component housing package of the present invention, the optical semiconductor element 4 is bonded and fixed to the upper surface of the mounting portion 1a of the insulating base 1 with an adhesive, and each electrode of the optical semiconductor element 4 is connected to the bonding wire 6. Is electrically connected to the metallized wiring layer 5 through the metal cap 2, and then the metal cap 2 is welded to the flange member 9 attached to the insulating base 1,
An electronic device as a product is obtained by hermetically sealing the optical semiconductor element 4 inside the container 3 including the insulating base 1 and the metal cap 2. The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the gist of the present invention. For example, in the example of the above-described embodiment, an electronic component housing package for housing an optical semiconductor element has been described as an example. However, the electronic component housing package of the present invention is an electronic housing for other electronic components such as a piezoelectric vibrator. It goes without saying that the present invention can be applied to a component storage package. According to the electronic component housing package of the present invention, the thickness of the flat annular flange member attached to the outer peripheral edge of the insulating base and to which the metal cap is welded is such that the outer peripheral side of the outer peripheral portion is the inner peripheral portion. Because the outer dimensions of the flange member were reduced in order to reduce the size of the electronic device,
Even when the width of the outer peripheral portion protruding from the insulating base becomes narrow, the thermal stress generated by the welding heat when welding the metal cap to the outer peripheral portion is limited by the thin inner peripheral portion of the flange member. The side is flexibly absorbed and alleviated, and as a result, the flange member is effectively prevented from peeling off from the insulating base and generating cracks in the insulating base. Further, since the thickness of the flange member is large on the outer peripheral side of the outer peripheral portion, the mechanical strength of the outer peripheral portion is maintained on the thick outer peripheral side. Even when an external force is applied, the outer peripheral portion is not easily deformed by the external force. Therefore, when the flange member and the metal cap are joined by welding, the flange member and the metal cap can be satisfactorily welded, and a compact and highly airtight electronic component housing package can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an example of an embodiment when an electronic component housing package of the present invention is applied to an electronic component housing package for housing an optical semiconductor element. FIG. 2 is a cross-sectional view showing a conventional electronic component storage package. [Description of Signs] 1 ... Insulating base 2 ... Metal cap 2a ... Flange 3 ... Container 4 ... Optical semiconductor element (electronic component) 9 ... Flange member 9a ... outer periphery

Claims (1)

(1) An insulating substrate having a mounting portion on which an electronic component is mounted on an upper surface, and attached to an outer peripheral edge of the insulating substrate, the outer peripheral portion protruding outside the insulating substrate. For storing electronic parts, comprising: a flat annular flange member having a flange portion having a substantially same outer peripheral dimension as the flange member at its lower end; and a metal cap joined to the flange member by welding while the flange portion is being pressed against the flange member. In the package, the thickness of the outer peripheral portion of the flange member is greater than the thickness of the inner peripheral portion of the outer peripheral portion .