An electronic component device and its manufacturing method

Abstract: Simplified structures for connecting electrodes of an electronic component contained in an envelope with lead-out electrodes are disclosed. Through holes are formed on the envelope, and metal foils are attached to the ends of the through holes at the envelope's inner side, with which electrodes of the electronic component are connected.

Description: BACKGROUND OF THE INVENTION Field of Application in Industry The present invention relates to an electronic component device comprising electronic component elements contained in an envelope, and its manufacturing method. Prior Art With a conventional electronic component device using an envelope of insulating properties, terminals of an electronic component element contained in the envelope have been taken out for electrical connections as follows: Through holes are made on the envelope, and these holes are covered with a metallic body inside thereof. One end of the metallic body exposed inside the envelope is connected to an electrode formed on the electronic component element, and the other end of the metallic body exposed outside the envelope serves as a lead out terminal. A problem involved with the foregoing prior art is in that connections between the metallic body and the electrode formed on the electronic component element tend to become complicated. More specifically, the foregoing connections are performed by first forming a projecting bump either on the metallic body inside the envelope or on the electrode of the electronic component element, and then by pressing the bump against the opposing object. Forming the aforementioned bump requires a plating process. Besides, it takes a long time to form the projecting bump by the plating process, and also preparations for various masks are needed before plating. All of these have resulted in complex connecting processes. Document US-A-5,250,870, discloses a device contained in an envelope, having a metalic connector which electrically connects a through hole metalisation to the device. Document JP 62,056,012 discloses a device having through hole sealed by a metal plate and them soldered annual. SUMMARY OF THE INVENTION The object of the present invention is to provide an electronic component device whereby processes for connection between an electronic component element contained in an envelope of electrically insulating properties and external connecting terminals disposed on the envelope are simplified. In order to achieve the foregoing object, the electronic component device of the present invention comprises an envelope of insulating properties, an electronic component element contained in the foregoing envelope, through holes made at specified places of the envelope, an electroconductive layer disposed all over the internal surface of each of the through holes made at specified places of the envelope, and a metal foil which covers tightly the through hole's opening situated inside the envelope and connects with an electrode formed on the electronic component element. According to the foregoing structures, the metal foil is pressed, while the configuration thereof being deformed, against the electrode formed on the electronic component element to complete connections between the both, enabling to realize simplified connecting structures. As a result, it is no longer needed to form projecting bumps by plating as it used to be according to the prior art, and photoprocessing for plating is no longer required, either. Consequently, the structures of the electronic component device have been made much simpler with a resultant contribution to easier production. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a partially cut away perspective view of an electronic component device as an exemplary embodiment of the present invention. Fig. 2 is an exploded perspective view of the electronic component device as shown in Fig. 1. Fig. 3 is a cross-sectional view of the electronic component device as shown in Fig. 1. Fig. 4 is a cross-sectional view of an electronic component device as another exemplary embodiment of the present invention. Fig. 5 is a top plan view of an example of a cover assembled into an electronic component device of the present invention. Fig. 6 is a bottom plan view of the cover as shown in Fig. 5. Fig. 7 is a cross-sectional view of an electronic component device of the present invention to show an example of the manufacturing method thereof. Fig. 8 is a cross-sectional view of another example of a cover assembled in to an electronic component device of the present invention. Fig. 9 is a cross-sectional view of another example of a cover and envelope assembled into an electronic component device of the present invention. Fig. 10 is a cross-sectional view of another example of a cover assembled into an electronic component device of the present invention. DETAILED DESCRIPTION OF THE INVENTION The invention is defined by the appended Claims. The present invention will be explained with the help of examples. Example 1 A partially cut away perspective view of an important part of an electronic component device is shown in Fig. 1 as an exemplary embodiment of the present invention, and an exploded perspective view of the foregoing electronic component device is shown in Fig. 2. Also, a cross-sectional view of the same is shown in Fig. 3. A top plan view of the cover of the envelope for the same is shown in Fig. 5. A bottom plan view of the foregoing cover is shown in Fig. 6. In Fig. 1, Fig. 2 and Fig. 3, there is a SAW (Surface Acoustic Wave) filter is contained as an electronic component element 2 in a glass-made saucer shell 1 of open upper side with its upper opening closed by a cover 3 made of glass. An envelope is formed of the saucer shell 1 and cover 3. The bottom surface of the electronic component element 2 is fixed to the inner bottom of the saucer shell 1 by an adhesive 4. The upper edge surface of the saucer shell 1 and the opposing periphery of the lower surface of the cover 3 are both mirror finished, and then pressed against each other under a temperature of about 300 °C to realize an interatomic bonding there between. On account of the interatomic bonding realized in putting the saucer shell 1 and cover 3 together, the bonding strength is so strong that the both members cannot be separated under the normal conditions of usage in terms of temperature, external mechanical force or the like, and adhesion between the two members is excellent. As shown in Fig. 2 and Fig. 3, a comb like electrode 5 made of aluminum is formed on the upper surface of the electronic component element 2, and an input or output electrode 6 is formed on each respective end thereof. Two of the through hole 7 are formed on the cover 3 at two positions opposite to the foregoing electrodes 6. As illustrated in Fig. 1, Fig. 3 and Fig. 5, two of an electrode 8 for outside connection are disposed around the periphery of each respective through hole 7 on the upper surface of the cover 3 with an insulator separating the two of the electrode 8 from each other. Also, as shown in Fig. 1, Fig. 3 and Fig. 6, a shielding electrode 9 and a connecting electrode 10 are disposed on the bottom surface of the cover 3. The connecting electrode 10 is shaped like a ring and placed around the periphery of at least one of the through holes 7. Besides, as shown in Fig. 6, a ring-like non-electrode member 11 is formed between the connecting electrode 10 and the shielding electrode 9 for separating electrically the former from the latter. The shielding electrode 9 and connecting electrode 10 are connected respectively by way of an electric conductor 12 formed inside each respective through hole 7, as shown in Fig. 3, to two of the electrode 8 for outside connection which are formed on the upper surface of the cover 3 and insulated electrically from each other. The shape of the electric conductor 12 is, for example, cylindrical. As shown in Fig. 1 and Fig. 3, a disc-like metal foil 13 made of aluminum and measuring 5 um to 200 um in thickness covers tightly each respective lower end of the through hole 7 exposed at the bottom surface of the cover 3. The metal foil 13 and the shielding electrode 9 or connecting electrode 10 are fused together at the external periphery of each of the through holes 7. Accordingly, the whole envelope is sealed air-tight by way of the adhesion between the foregoing saucer shell 1 and outer periphery of the cover 3, and the hermetic sealing by the metal foil 13. Thus, the electrodes 6 formed on the electronic component element 2 are connected in series to the metal foils 13, the connecting electrode 10 or shielding electrode 9, the electric conductors 12 and the electrodes 8 for outside connection for an electrical lead-out to outside. Fig. 7 is a cross-sectional view to explain an important part of the manufacturing method for the present example's electronic component device. In Fig. 7, the same symbols as used in Fig. 3 are employed. As illustrated in Fig. 7, an ultrasonic transducer 14 is inserted into the through hole 7, thereby the metal foil 13 being pressed downward and brought in touch with the input or output electrode 6. At this time, ultrasonic vibrations are applied to the ultrasonic transducer 14, and the above two members are ultrasonically welded at the point where the two members meet with each other. As a result, the electrode 8 for outside connection in one section of the electronic component device 1 has been connected with the electrode 6 formed on the electronic component element 2 of the same section as above by way of the electric conductor 12, connecting electrode 10 and metal foil 13. Also, the electrode 8 for outside connection in another section of the electronic component device 1 will be connected electrically with the electrode 6 formed on the electronic component element 2 of the same section as above by way of the electric conductor 12, shielding electrode 9 and metal foil 13. The electrode 8 for outside connection, shielding electrode 9, connecting electrode 10 and electric conductor 12 can be made of, for example, Au alone, Cu alone, Au film formed on Cu film or the like. In place of Al, the metal foil 13 can be made of, for example, Au alone, a laminate of Au and Al, a laminate of Au and Sn, a laminate of Au and solder, a laminate of Al and Sn, a laminate of Al and solder, a laminate of AL and AU and SN , a laminate of AL and AU and solder, a laminate of Au and a barrier layer and AL, a laminate of AU and a barrier layer and SN, a laminate of Au and a barrier layer and solder, a laminate of A1 and a barrier layer and Sn, a laminate of A1 and a barrier layer and solder, or the like. The barrier layer can be made of, for example, Mo, Ti, W, Cr or the like. In place of glass, the saucer shell 1 and cover 2 can be made of alumina or various ceramics with an electrically insulating property. Besides, in place of a SAW filter, the electronic component element can be a quartz oscillator, a ceramic filter or the like. Further, in place of Al, the comb-like electrode 5 can be made of, for example, Au, W, Cr or the like. In addition, the metal foil 13 can be structured in such a way as the electric conductor 12 is directly connected therewith. It is also possible to employ a structure wherein in the connecting electrode 10 and shielding electrode 9 are omitted. In this case, the metal foil 13 and electric conductor 12 are electrically connected directly with each other. Example 2 Next, another exemplary embodiment of the present invention for an electronic component device will be explained. Fig. 4 shows a cross-sectional view of an important part of the another exemplary embodiment of the present invention for an electronic component device. In Fig. 4, the same symbols as used in Fig. 3 are employed to identify each respective member. The electronic component device as shown in Fig. 4 is different from the one shown in Fig. 2 in having an electronic component element 2 not fixed by means of an adhesive material, being instead suspended in the air by means of a metal foil 13 with an air gap created between the bottom of the electronic component element 2 and a saucer shell 1. When the electronic component element 2 is fixed directly onto the saucer shell 1 which has an expansion coefficient different from that of the electronic component element 2, a mechanical stress will be imposed on the electronic component element 2 according to ambient temperature changes and the characteristics thereof may be altered. With the present example, no adhesive material is used and the electronic component element 2 is fixed by means of the metal foil 13 to avoid the aforementioned problem. In this case, the metal foil 13 is readily deformed and the electronic component element 2 is allowed to expand or shrink freely. As a result, no mechanical stress is imposed on the electronic component element 2 and changes in the characteristics thereof are less likely to occur. Each respective member that builds the electronic component device of the present example is the same as was used in Example 1. It is particularly preferred to use a SAW filter as the electronic component element 2. Example 3 Next, still another exemplary embodiment of the present invention for an electronic component device will be explained. The electronic component device of the present example is different from that of the foregoing Example 1 in structures of the cover for the envelope. Fig. 8 is a cross-sectional view of an important part of the cover employed in the electronic component device of the present example. All the other structural members are the same as those used in the electronic component device of Example 1. In Fig. 8, the cover 15 is formed of a thin plate of metal such as Ni(42%)/Fe, Ni(46%)/Fe alloy or the like, the expansion coefficient of which is similar to that of glass or alumina. Through holes 16 are formed on the thin plate of the metal as above. Insulating layers 17 are disposed on the upper and bottom surfaces of the metallic cover 15, and also on the inner surfaces of the through holes 16. On the insulating layers 17, electrodes 8 for outside connection, electric conductors 12, shielding electrodes 9, a connecting electrode 10 and metal foils 13 are formed in the same way as in the electronic component device of Example 1. The cover 15 thus structured is joined together with the glass or ceramic saucer shell containing an electronic component element. The metal foil 13 is preferred to have structures wherein Mo or W is used as a core material, at least one metal selected from Au, Sn and solder is laminated on the surface of the core material at the side of the cover 15, and either Au or Al is laminated on the surface of the core material at the side of the electronic component element. An organic material such as epoxy resin, polyester resin and the like, or an inorganic material such as glass, ceramics and the like, for example, is used as the insulating layer 17. On account of the metallic cover thus structured, an effect to facilitate production of the through holes 16 is gained. Example 4 The electronic component device of the this particular exemplary embodiment of the present invention is different from that of Example 1 in structures of the saucer shell and cover serving as the envelope. Fig. 9 is a cross-sectional view of an important part of the saucer shell and cover serving as the envelope and employed in the electronic component device of the present example. All the other structural members are the same as those used in the electronic component device of Example 1. In Fig. 9, the envelope is composed of a saucer shell 22 which is formed of resin and open in the upper side, and a cover 19 which is formed of resin and covers the upper opening of the saucer shell 22. A metallic thin layer 24 is disposed on all over the inner surfaces of the saucer shell 22 for an anti-moisture provision. Through holes 7 are formed in the foregoing cover 19. The openings of the through holes 7 facing the electronic component element are covered by a metal foil 18 for an anti-moisture effect and an electro-magnetic shielding effect as well. Electro-conducting layers 20 and 21 are disposed on the inner side surfaces of the foregoing through holes 7 and on the surfaces of the metal foil 18 exposed to the through holes, respectively. In this case also, as explained in the foregoing Example 1. a ring-like non-electrode member 11, namely an insulating area, is formed on the metal foil 18 in the periphery of at least one of the through holes 7, thereby separating the metal foil formed on the bottom surface of one through hole from that of the other through hole to establish structures wherein in respective electrodes are disposed independently from each other. The same material as was used for the metal foil 13 described in Example 1 is used as the material for the metal foil 18. As the material for the electro-conducting layers 20 and 21, the same material as was used for the conductor 12 described in Example 1 is used. As the material for the saucer shell 22 and cover 19, epoxy resin, phenol resin, various engineering plastics and the like are typically used. Example 5 The electronic component device of the this particular exemplary embodiment of the present invention is different from that of the foregoing Example 1 in structures of the cover for the envelope. Fig. 10 is a cross-sectional view of an important part of the cover of the envelope employed in the electronic component device of the present example. All the other structural members are the same as those used in the electronic component device of Example 1. As shown in Fig. 10, a metal foil 18 is formed on the electronic component element side of a glass-made cover 3 continuously, covering the openings of through holes 7. As the material for the metal foil 13, aluminum is used. An area of the metal foil corresponding to a ring-like non-electrode member 11 formed in the periphery of at least one of the through holes 7 is transformed to an aluminum oxide layer region through an an ode oxidation processing of aluminum. In addition, electro-conducting layers 20 and 21 are disposed on the inner side surfaces of the through holes 7 and on the surface of the metal foil 18 exposed to the feed through holes 7, respectively. Further, the method employed in joining the metal foil 18 made of aluminum and the glass-made cover 3 together may be by way of a direct connection performed according to an electro-static bonding method in addition to by way of an ordinary bonding method. According to the structures described in the foregoing Example 1 to Example 5, a connecting means can have an access to a metal foil through a through hole, thereby having the metal foil pressed and deformed toward an electrode of an electronic component element, and then a direct connection between the metal foil and the electrode can be carried out, resulting in simplified processes for connection between the electrodes formed on the electronic component element and the electric conductors formed on the envelope. In other words, there is no need of forming conventional projected bumps by plating, thereby eliminating a photoprocessing for plating, as a matter of course. As a result, the electrodes formed on the electronic component element can be easily connected with the electric conductors formed on the envelope without touching at all the electronic component element hermetically sealed in the envelope. Besides, the whole structures have been made simplified with a resultant contribution to realizing a simpler production process. So far, descriptions have been made on an electronic component device of the present invention wherein the electronic component element was a SAW filter, but the electronic component element can not be limited to a SAW filter. The electronic component element can be, for example, an oscillating device of various types such as a quartz crystal oscillator, a ceramic oscillator and the like, or a ceramic filter and the like.

Claims: An electronic component device comprising: an envelope (19,22) having through holes (7) at specified places thereof; an electronic component element (2) contained in said envelope and having electrodes (5) formed thereon: electric conductors (20) disposed on the inner surfaces of said through holes: and metal foils (18) electrically connected to said electrodes and said electric conductors, and disposed on one end of said respective through holes, which is situated towards the inside of said envelope, to seal off the ends of said respective through holes. The electronic component device according to Claim 1, wherein said envelope is formed of at least one selected from a group of glass, ceramics and resins. The electronic component device according to Claim 1, further comprising electrodes for outside connection formed on the external surfaces of said envelope with said electrodes connected to said respective electric conductors disposed on the inner surfaces of said through holes. The electronic component device according to Claim 1, wherein said envelope is composed of a saucer shell (22) with the upper side thereof left uncovered and a cover (19) closing the upper opening of said saucer shell. The electronic component device according to Claim 1, wherein said metal foils are formed of at least one selected from a group of Al, Au, a laminate of Au and Al, a laminate of Au and Sn, a laminate of Au and solder, a laminate of Al and Sn, a laminate of Al and solder, a laminate of Al and Au and Sn, and a laminate of Al and Au and solder. The electronic component device according to Claim 1, wherein said metal foils are formed of one selected from a group of a laminate of Au and a barrier layer and Al, a laminate of Au and a barrier layer and Sn, a laminate of Au and a barrier layer and solder, a laminate of Al and a barrier layer and Sn, and a laminate of Al and a barrier layer and solder. The electronic component device according to Claim 6, wherein said barrier layer is formed of at least one selected from a group of Mo, Ti, W and Cr. The electronic component device according to Claim 1. wherein said electrodes disposed on said electronic component element are formed of aluminum, and said metal foils are formed of aluminum. The electronic component device according to Claim 1, further comprising connecting electrodes formed on inner surfaces of said envelope in the periphery of at least one of said through holes, and said connecting electrodes, said electric conductors and said metal foils are electrically connected with one another. The electronic component device according to Claim 1, further comprising shielding electrodes (9) formed on inner surfaces of said envelope in the periphery of at least one of said through holes, and said shielding electrodes, said electric conductors and said metal foils are electrically connected with one another. An electronic component device comprising: a saucer shell (1) which has the upper part thereof left uncovered and is formed of glass or ceramics; a cover (3) which comprises a substrate formed of a Fe-Ni alloy and arranged with through holes (7) at specified places thereof, and insulating layers (17) disposed on the upper and bottom surfaces of said substrate and also on the inner surfaces of said through holes, and covers the upper opening of said saucer shell; an electronic component element (2) contained in said saucer shell and having electrodes (5) formed thereon; electric conductors (12) disposed on the inner surfaces of said through holes; and metal foils (13) electrically connected to said electrodes and said electric conductors, and disposed on the inner surfaces of said cover to seal off the ends of said respective through holes. The electronic component device according to Claim 11, wherein said metal foils are formed of laminates comprising at least one selected from a group of Mo and W as a basic material. The electronic component device according to Claim 12, wherein said metal foils have multilayer structures of laminating at least one metal selected from Au, Sn and solder over said cover side surfaces of said basic material, and of laminating at least one metal selected from a group of Au and Al over said electronic component element side surfaces of said basic material. An electronic component device comprising: a resin made saucer shell (22) which has a metal film layer formed on the inner surface thereof and has the upper side thereof left uncovered; a resin made cover (19) arranged with through holes at specified places thereof and disposed to cover the upper opening of said saucer shell; an electronic component element (2) contained in said saucer shell and having electrodes (5) formed thereon: electric conductors (12) disposed on the inner surfaces of said through holes; and metal foils (13) electrically connected to said electrodes and said electric conductors, and disposed on the inner surfaces of said cover to seal off the ends of said respective through holes. The electronic component device according to Claim 14, wherein said metal foils disposed on the inner surfaces of said respective through holes are of a flat plate like shape to cover the opening of said saucer shell, and also a non-electrode formed area is disposed in the periphery of at least one of said through holes situated on said metal foils. An electronic component device comprising: a saucer shell (22) which has the upper part thereof left uncovered and is formed of glass or ceramics; a cover (19) arranged with through holes at specified places thereof and disposed to cover the upper opening side of said saucer shell; an electronic component element (13) disposed inside said saucer shell and having electrodes (5) formed thereon: electric conductors (12) disposed on the inner surfaces of said through holes; metal foils (13) formed of aluminum which are electrically connected to said electrodes and said electric conductors, and disposed so as to cover said through holes; and a ring like region (11) of aluminum oxide, which was formed by an anode oxidation method, disposed in the periphery of at least one of said through holes situated on said metal foils. The electronic component device according to Claim 16, wherein said metal foils and said cover have been joined together by an electrostatic bonding method. An electronic component device comprising: an envelope (19,22) having through holes 7 arranged at specified places thereof; an electronic component element (2) contained in said envelope and having electrodes formed thereon: electric conductors (12) disposed on the inner surfaces of said through holes; and metal foils (13) electrically connected to said electrodes and said electric conductors, and disposed on one end of said respective through holes, which is situated towards the inside of said envelope, to seal off the ends of said respective through holes, and also having said electronic component element supported in suspension in the air by means of said metal foils in addition to having said metal foils connected electrically with said electrodes. A manufacturing method for an electronic component device comprising the steps of: (a) placing an electronic component element (2) with electrodes formed thereon inside a saucer shell (1) with the upper side thereof uncovered; (b) disposing metal foils (13) on a first surface of a cover (3), on which through holes (7) are formed, so as to cover said through holes; (c) assembling an envelope by joining together said cover having the first surface, where said metal foils have been disposed, faced towards inside and the saucer shell wherein said electronic component element has been contained; and then (d) inserting jigs (14) into said through holes from the outside of said cover to press down said metal foils, and joining together by pressing said electrodes formed on said electronic component element and said metal foils at places where said jigs are pressed down. The method for manufacturing an electronic component device according to Claim 19, wherein said jigs are ultrasonic transducers, and said electrodes and metal foils are joined together by welding due to an effect of said ultrasonic transducers.

Inventors: KONDO SHUJI, KONDO, SHUJI
Applicants: MATSUSHITA ELECTRIC IND CO LTD, MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Application year: 1995
Main classification: H03H3
IPC codes: H03H9, H03H3