JP2000040762A - Electronic element sealing package and electronic element sealing structure - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A problem that a sealed package or an electronic element sealing structure using a ceramic material cannot effectively shield an electronic element piece sealed therein from an external electromagnetic field. There is. A package for sealing an electronic element in which a cap made of a conductive material is covered on a ceramic base.
0, a metal thin film 13 made of gold or / and silver is formed on the surface of the cap 12.
The cap 12 is adhered on the ceramic base 11 by disposing a conductive adhesive 14 at the portion where the ceramic base 11 is formed, and the cap 12 is grounded via the ground electrode 15 of the ceramic base 11. Provided is a package for sealing an electronic element, which can be led to a potential.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package for sealing an electronic element, for sealing an electronic element, and a conductive glass sealing package using a conductive glass for sealing the electronic element. The present invention relates to an electronic element sealing structure, and particularly has an electromagnetic shielding effect on electronic elements.

[0002]

2. Description of the Related Art It is not good to leave an electronic element, for example, a quartz oscillator, a piezoelectric element, a semiconductor device, or the like in a state of being directly exposed to the outside air in use, so that it is generally housed in a package of some form. Are in use.
After being assembled in a package, it is actually assembled in a printed circuit board structure or the like so as to constitute a part of an electronic circuit. For example, when packaging an electronic element such as a quartz oscillator or a piezoelectric element, a package as shown in FIG. 11 is used.

FIG. 11 shows a ceramic base 11.
Some electronic element pieces 112 are packaged inside an electronic element encapsulating package 110 composed of the electronic element sealing cap 110 and the cap 113. By closing the lid, the electronic element pieces 112 housed inside are directly exposed to the external environment. Thus, the function of the electronic element piece 112 can be sufficiently ensured even in a bad environment. For example, such a package material is made of a ceramic having alumina as a main material, and an electronic element piece such as a quartz oscillator or a piezoelectric element is used as an electronic element piece housed therein.

After such packaging, the sealed electronic element sealing structure is mounted on a printed circuit board structure by solder reflow or the like to form an electronic circuit integrally with other electronic elements. ing. By the way, this type of package is suitable for so-called surface mounting, and its use is increasing in recent years because its thermal expansion coefficient is relatively easy to match with an electronic element piece to be housed and sealed therein.

[0005] Referring briefly to FIG. 11, what is drawn between the upper and lower ceramic bases 111 and the cap 113 is an electronic element piece 112 such as a quartz oscillator or a piezoelectric element. Is physically fixed on the ceramic base 111 by two electrodes 118 provided on the ceramic base 111 and is electrically connected to the ceramic base 111. In a state where the electronic element piece 112 is fixed on the ceramic base 111, a sealing material 114 is attached to a bonding interface between the ceramic base 111 and the cap 113.
Is applied and pressure is applied from above and below, and the ceramic base 111 and the cap 113 are completely sealed with the sealing material 114 to completely protect the electronic element piece 112 from the surrounding environment.

[0006] Looking at the packaging generally used in conventional semiconductor devices and the like, this is as shown in FIG. The packaging used for the semiconductor element piece 123 has a structure in which the semiconductor element piece 123 is mounted on a lead frame 122, necessary wire bonding 124 is performed, and then the resin element 125 is integrally sealed with the lead frame 122. .

The semiconductor device 120 completed as described above
Has been the mainstream as a semiconductor device structure up to the present because of its high reliability and low cost. However, with the recent improvement in the performance of the semiconductor device, the semiconductor device has become weak to minute stress. At the same time, the current consumption increases and the heat generation increases, so that the conventional sealing resin cannot sufficiently release the heat, or problems such as adverse effects due to the thermal stress of the sealing resin generated by the heat are remarkable. Has become.

[0008]

As described above, conventionally, an electronic element piece, such as a quartz oscillator, a piezoelectric element, or a semiconductor element piece, is conventionally provided with an electronic element sealing package or a sealing resin made of a ceramic material. Has been performed, but for a sealed package or an electronic element sealing structure using a ceramic material, an electronic element piece sealed therein is effectively shielded from an external electromagnetic field. There is a problem that you can not.

In general, electronic element pieces used by such packaging are required to operate with extremely high precision and are sensitive to the external environment, that is, humidity, gas, etc., and are affected by them. And the influence of the electromagnetic field is also a problem. If the electromagnetic field cannot be effectively shielded, the operation of the element may not be guaranteed in some cases.

However, in the case of a ceramic package using a ceramic material which has been conventionally used, since the material of the ceramic package itself is generally a material that cannot be shielded from electromagnetic waves, that is, is not a conductive material, an electromagnetic field is particularly contained inside. In the case of sealing an electronic element piece which is susceptible to the influence of electromagnetic waves, it is necessary to separately provide a structure for electromagnetic shielding.

Further, in the case of a conventional sealing structure made of resin for packaging a semiconductor element piece shown in FIG. 12, as in the case of packaging made of a ceramic material, an electromagnetic field from the outside cannot be effectively shielded. As described above, despite the fact that it is necessary to sufficiently release the heat to the outside due to the large current consumption, there is a case where the heat conductivity of the resin adversely affects the heat at present. I have.

In addition, since the semiconductor element pieces encapsulated therein become more and more sensitive to external stress as the density of the semiconductor elements becomes higher and higher, when the whole is tightly sealed with a resin, There is also a problem that the thermal stress or the stress caused by the application of a simple mechanical resin adversely affects the semiconductor element piece.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides the following conductive glass sealing package and an electronic element sealing structure using the same. That is, an electronic element sealing package in which a cap made of a conductive material is covered on a ceramic base, and a metal thin film made of gold or / and silver is formed on a surface of the cap. A conductive adhesive is disposed on the portion where the thin film is formed, the cap is attached to the ceramic base, and the cap is led to a ground potential via a ground electrode of the ceramic base. Provided is a package for sealing an electronic element.

The electronic device sealing package according to claim 1, wherein the conductive adhesive is a conductive glass in which conductive particles made of a metal material are dispersed in a glass component.
Offer Further, the present invention provides the package for sealing an electronic element according to any one of claims 1 and 2, wherein the cap is made of a metal material or a conductive ceramic material. Further, the ceramic base has a coefficient of thermal expansion of 100 to 100, which is obtained by dispersing forsterite in glass at 30 to 70 wt%.
3. The cap according to claim 1, wherein said cap is made of a glass-ceramic composite material of 150 × 10 ^-7 and said cap is made of a nickel-iron alloy.
And a package for encapsulating an electronic element according to the item (1).

An electronic element sealing structure in which a cap made of a conductive material is covered on a ceramic base on which a crystal resonator element is disposed, wherein the ceramic base contains forsterite in glass. The cap is made of a glass-ceramic composite material having a thermal expansion coefficient of 100 to 150 × 10 ⁻⁷ dispersed therein and the cap is made of an iron-nickel alloy, and a metal thin film made of gold or / and silver is formed on the surface;
A conductive adhesive is disposed on the portion where the metal thin film is formed, and the cap is attached to the ceramic base. The cap is led to the ground potential via the ground electrode of the ceramic base. The present invention provides an electronic element sealing structure that can be used.

An electronic element sealing structure in which a piezoelectric material element piece is sealed as the electronic element in the electronic element sealing package according to any one of claims 1 and 2. The electronic element sealing structure according to claim 5, wherein the base is substantially rectangular, and the substantially rectangular electronic element is fixed at both ends in the longitudinal direction.

Further, the present invention provides the electronic device sealing package according to any one of claims 1 to 4, wherein an oxide film is formed on a surface of the cap.

The present invention also provides an electronic element sealing structure according to any one of claims 5 to 7, wherein an oxide film is formed on a surface of the cap.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in order of claims described in the appended claims with reference to the drawings. First, the invention according to claim 1 will be described with reference to FIGS. The invention according to claim 1 is a package for sealing an electronic element in which a cap made of a conductive material is covered on a ceramic base, wherein the cap has a metal thin film made of gold and / or silver on its surface. Is formed, a conductive adhesive is disposed on the portion where the metal thin film is formed, and the cap is attached to the ceramic base. The cap is attached to the ceramic base via a ground electrode of the ceramic base. This is an electronic element sealing package that can be led to the ground potential.

FIGS. 1 and 2 show the first embodiment of the present invention in a typical diagram. FIG. 1 shows a state in which a plate-like cap 12 made of a conductive material is covered on a ceramic base 11, and a part of the cap 12 is cut off so that the inside can be seen. A feature of the present invention is that the cap itself is made of a conductive material, and when the cap 12 and the ceramic base 11 are bonded together, gold or / and silver Metal thin film 1
3 is formed, and a conductive adhesive 14 is disposed on a portion where the metal thin film 13 is formed, or the cap 12 is bonded to the ceramic base 11 so as to be disposed. is there.

First, the cap 12 is made of a conductive material. The reason why the cap 12 is made of a conductive material is that the conductive material has an electromagnetic shielding effect. Therefore, the cap 12 covers the entire electronic element piece 16 disposed on the ceramic base 11, so that even when an electromagnetic wave is applied to the electronic element piece 16 from the outside, particularly from the upper surface side, the cap 12 can be used. This prevents electromagnetic waves from being shielded from affecting the electronic element piece 16 disposed on the ceramic base 11.

Further, in order to effectively provide the cap 12 with an electromagnetic shielding effect, the material of the cap 12 is not merely made of a conductive material, but the cap 12 is provided with the ground electrode 15 of the ceramic base 11. There is also a characteristic in that it is led to the ground potential via the ground. When guided to the ground potential in this way, the state of the cap 12 can always be kept at zero potential even when an electromagnetic wave hits the cap, so that electromagnetic shielding can be effectively performed.

A further feature of the present invention is that the cap 12
Is that the metal thin film 13 is formed at the bonding portion between the metal base 11 and the ceramic base 11. Generally speaking, the ground electrode 15 and the cap 12 formed on the ceramic case 11
It seems that it is sufficient if the cap 12 is adhered to the ceramic base 11 with the conductive adhesive 14, but the cap 12 made of a conductive material is liable to be oxidized in practice, so that the actual conductive bonding An oxide film is formed on the surface on which the agent 14 is applied, though it is thin, and the formation of this oxide film increases the resistance of the connection between the ground electrode 15 formed on the ceramic base 11 and the cap 12. I have.

If the resistance value becomes large, the cap 12 cannot always be brought to zero volt, that is, the ground potential, so that the capability of electromagnetic shielding is affected. For example, when the metal thin film made of gold and / or silver is not formed on the surface of the cap as in the first aspect of the invention, the resistance value between the ground electrode and the cap is about 10 ohms to several tens of ohms. In the present invention, gold or / and / or
And when a metal thin film made of silver is formed, the resistance value becomes 1
It can be reduced to below ohms.

As described above, as the metal thin film made of gold and / or silver, it is conceivable to form a thin film using a material such as a silver paste or a material such as a gold paste. A substance such as a gold paste or a silver paste can be disposed on the cap by a method such as screen printing, or can be disposed by a method of dropping a small amount instead of screen printing. When a material such as a gold or silver paste is used, the temperature is then raised to about 400 ° C. to remove the solvent and form a gold or silver thin film.

It should be noted that the metal thin film made of gold and / or silver is only required to contain such a material. For example, the metal thin film may be made of a silver-palladium alloy, or may be made of gold and other metals. It goes without saying that it may be a mixture with a metal. By forming a metal thin film made of gold and / or silver on the portion of the cap where the conductive adhesive is disposed, the function of lowering the resistance value of the bonding portion can be achieved. It has to do with the mechanism of conduction between the cap.

The inside of the conductive adhesive contains fine particles of metal, for example, fine particles of silver, and the fine particles made of metal play an essential role in making the conductive adhesive conductive. Plays. However, if the cap is made of a conductive material and is sealed, but has a thin but oxidized film formed on the surface of the joining portion of the cap, the cap is made of a metal such as silver contained in the conductive adhesive. A phenomenon is observed in which non-conductive materials compatible with the oxide are concentrated on the surface of the cap without the fine particles adhering to the cap side.

Therefore, the metal particles contained in the conductive adhesive do not appear on the interface side of the cap, so that the conductivity is low. Of course, it does not mean that the metal particles contained in the conductive adhesive are not present at all on the cap side, but the metal particles contained in the conductive adhesive are oxidized on the cap side by oxidizing the surface of the cap in this way. The proportion that exists is reduced.

However, when a metal thin film made of gold and / or silver is formed on the surface of the cap as in the present invention, these metal thin films are hardly oxidized or compatible with silver particles contained in the conductive adhesive. For this reason, when a conductive adhesive is applied, metal particles contained in the conductive adhesive are distributed in such a manner as to sufficiently contact the cap.

Therefore, even if the cap is placed in an environment where it is oxidized, the portion is not oxidized, or the same metal as the silver particles contained in the conductive adhesive is present. Therefore, the familiarity of the metal particles in the conductive adhesive with the cap is improved, and the resistance value between the ground electrode and the cap of the ceramic base can be greatly reduced.

FIG. 2 also shows the ceramic base 21 and the cap 2
An electronic element piece 26 is arranged between the two, and has a structure basically similar to that of FIG. The difference from FIG. 1 lies in the arrangement of the ground electrode. In FIG. 1, the ground electrode 15 extends from the short side of the ceramic base 11 to the printed circuit board structure side, but in the case of FIG.
7 is provided, the inside of the concave portion 27 is covered with a metal material, and this portion is used as the ground electrode 25.

FIG. 3 shows a state in which an electronic element sealing package as shown in FIGS. 1 and 2 or an electronic element sealing structure 31 using the same is arranged on a printed circuit board 30. Things. When placed on a printed circuit board in this way, even if there is a component that generates strong electromagnetic waves around it, since the cap is conductive, it is necessary to provide another shielding mechanism especially. Without this, it becomes possible to electromagnetically shield the electronic element pieces inside the electronic element sealing package.

FIGS. 4 (a) and 4 (b) correspond to FIG.
7A and 7B show other examples 40a and 40b of the electronic device sealing package shown in FIG. In this case, the caps 42a and 42b have a shape like a lid of a lunch box unlike those in FIGS. 1 and 2, but in any case, gold or gold is formed on the inner or outer surface of the caps 42a and 42b. / And metal thin films 42af, 42b made of silver
Since f is formed and is led to the ground electrodes 45a and 45b of the ceramic bases 41a and 41b by the conductive adhesives 44a and 44b, it has a sufficiently good electromagnetic shielding effect.

Even when a bulky electronic element is housed inside by making the lunch box cover like this, a cap can be provided so as to enclose the entire electronic element, so that the electromagnetic shielding is prevented. The effect is great. FIG. 4 (a)
Shows a metal thin film 42af on the inner surface of the cap 42a.
The one shown in FIG. 4B is one in which a metal thin film 42bf is formed on the outer surface of a cap 42b.

In any case, the metal thin films 42af, 42b made of gold and / or silver are formed on the surfaces of the caps 42a, 42b.
f, and conductive adhesives 44a, 44b are disposed on the portion where the metal thin film is formed to form caps 42a, 42b.
b is attached to the ceramic bases 41a and 41b, and the caps 42a and 42b can be guided to the ground potential via the ground electrodes 45a and 45b of the ceramic base. The resistance value between the electrodes 45a, 45b and the caps 42a, 42b can be made extremely small, specifically, 1 ohm or less, and a large electromagnetic shielding effect can be realized.

FIG. 5 shows a simplified process of manufacturing this ceramic base. As mentioned above, when sealing a semiconductor element with a mold such as resin, the heat is a problem, but when sealing a semiconductor element in such a ceramic package, ceramics having a high thermal conductivity are used. By using the material, the heat generated by the semiconductor element piece is effectively eliminated to the outside, and the function of the semiconductor element piece is secured.

The case of manufacturing such a ceramic package base using, for example, alumina will be briefly described. This is shown in FIG. With the advancement of IC elements, higher density of wiring circuits, prevention of heat generation, protection from temperature / humidity changes and dust are required for substrates, and elements such as multilayered substrates, IC packages, and piezoelectric elements are combined. Although packages have evolved, the present invention is a further improvement of these, and the ceramic base material can be manufactured using a green sheet method.

The green sheet method is a method in which a conductive sheet is printed on a green sheet of glass, ceramic or alumina prepared by a doctor blade method and laminated and fired together. This is a method for manufacturing a ceramic base having a multi-layer circuit board or a multi-layer circuit which is extremely reliable for LSIs and VLSIs and for elements requiring even higher reliability.

The ceramic base produced by this method has many features. First, the first point is that high-density wiring is possible because a large number of sheets with fine wiring are easily laminated. . Therefore, by wiring the ceramic base of the electronic element sealing package in multiple layers, an element having many electrode points inside can be easily accommodated.

Secondly, since the insulating substrate and the conductor are formed by simultaneous firing, there is also an advantage that the integration is complete and the reliability is high. The basic manufacturing process of a ceramic body such as a multilayer circuit board by a green sheet method will be described. First, a raw material powder, a flux, an organic binder, a solvent, and a plasticizer are thoroughly mixed in a ball mill to form a slurry. This slurry is spread on a carrier tape by a blade and dried to obtain a green sheet.

This green sheet has a thickness of 0.1 to 1.
The thickness is about 0 mm, and the thickness can be adjusted as needed. A conductor paste made of metal powder is screen-printed on the green sheet. This conductor paste becomes an electrode material, and specifically, a ground electrode is also formed by this method. In the green sheet method, there are three methods of multi-layering, a sheet laminating method, a printing multi-layer method and a method using both of them, and the sheet laminating method is often used.

According to the sheet lamination method, a ceramic base body is manufactured by piercing a green sheet with a mold or a micro drill, filling the green sheet with a conductive paste, laminating a plurality of printed patterns, and firing. Is done. As a general specification of the ceramic base manufactured by such a sheet lamination method, the wiring material is such as silver, silver palladium, or copper, and the minimum line width is 0.08 mm.
The minimum line spacing is about 0.1 mm, the minimum through hole diameter is about 0.1 mm, and the minimum through hole pitch is about 0.25 mm.

As the material of the conventionally used material powder, alumina of about 90 to 94% is used as a material having good thermal conductivity, the coefficient of thermal expansion is 75 × 10 ⁻⁷ / ° C., and the dielectric constant is 8. 5. The specific resistance is about 10 ¹⁴ Ω / cm. The maximum number of sheets to be stacked in this way is 45.
Although it is possible to have up to about 10 layers, in such a ceramic package, if there are at most about 10 layers, a sufficiently high-density ceramic package, that is, an electronic element sealing package can be manufactured.

The step of integrating a plurality of green sheets will be described with reference to FIG. Generally, a so-called CIP method is used for low-temperature isotropic consolidation molding. In the CIP method, a laminated green sheet as an original material is put into a rubber bag, which is put into a pressure transmitting liquid (pure viscous liquid) put in a compression container, and the transmitting liquid is compressed. Then, the raw material powder in the bag is isotropically compacted by the Pascal pressure generated in the transmission liquid.

Since it is tightened isotropically from all directions by the Pascal pressure, a higher degree of isostatic pressing and high-density uniform pressing can be achieved as compared with uniaxial consolidation. For this reason, a high-density formed body excellent in preservation can be obtained, and it is most suitable as a method for manufacturing a ceramic base for electronic element sealing.

In this method, first, a ceramic sheet is processed into a green sheet 60 punched into a desired shape and green sheets 61 and 62 on which a pattern is printed.
A step of laminating these green sheets 61 and 62 to form a laminate 63;
, Packaging the green sheet laminate 63, evacuating the packaged plastic bag 64, bringing the plastic bag 64 into close contact with the green sheet laminate 63, and isostatic pressing. Has become.

Incidentally, in addition to low-temperature isostatic consolidation molding, there is also a type using high-temperature isostatic consolidation molding, so-called HIP, but the same is in principle the same. The reason why the low-temperature isotropic consolidation molding is performed is to soften the binder contained in the sheet by performing isotropic pressing, and to bond the green sheets with the softened binder to complete the ceramic body. Conventionally, low-temperature isotropic consolidation molding was mainly performed in forming a green sheet as described above, but the present inventors have further found an optimal method for forming a ceramic base.

In this method, the ceramic sheets 61, 62
It is not necessary to repeat the process of stacking the bags accurately in a plastic bag 64 and evacuating several times.
Such a problem that a large amount of waste is generated can be avoided. That is, this is a method of manufacturing a ceramic body formed by laminating green sheets 61 and 62, a step of applying a solvent for dissolving a binder contained in the green sheets 61 and 62 to the lamination surface of the green sheets, and applying the solvent. This is a method for manufacturing a ceramic base, comprising a step of stacking the green sheets thus pressed, a step of pressing and integrating the stacked green sheets, and a step of firing the pressed green sheets.

Regarding such a method, the application of the solvent can be performed by bringing the wet mesh sheet into close contact with the lamination surface of the green sheet, or by spraying a solvent vapor onto the lamination surface. In the step of pressing and integrating the laminated green sheets, it is preferable to perform the pressing at a pressure of 1 kg / cm ^{2 to} 10 kg / cm ² . Also, in one-way press, 3
Adhesion is possible at around 0 to 50 kg / cm ² 100 ° C. Low pressure bonding is also possible by reviewing the plasticizer in the green sheet.

The binder can be designed by polyvinyl butyral, and the solvent can be designed by an appropriate combination of methanol, ethanol, isopropyl alcohol and N-butanol. The solvent may be a combination of cyclohexanone and isophorone, the binder may be polyvinyl butyral, and the solvent may be NN-dimethylformamide. As described above, the present inventors have also found an inexpensive and reliable method for manufacturing a ceramic base in an electronic element sealing package.

Next, the conductive sealant will be briefly described. Claim 2 claims this.
That is, in the invention according to claim 2, as described above, the conductive adhesive is a conductive glass in which conductive particles made of a metal material are dispersed in a glass component. It is a package for stopping. Generally, an organic sealant is first considered as a conductive sealant, but some of the binders in the organic sealant generate gas when heated to a high temperature. Such a gas may adversely affect the electronic element pieces sealed in the sealing package.

Accordingly, glass is considered as a material which does not generate such a gas, and among these glasses, a conductive adhesive in which conductive particles are dispersed in glass is particularly suitable as the conductive adhesive according to claim 1. It can be said that it is. This is shown in FIGS. 7A and 7B. The point is that the metal particles 72 in the conductive adhesive 70 composed of the metal particles 72 and the glass binder 73 should be continuously connected. As a result, as shown in FIG. 8, electricity flows to the portion where the metal particles 82 in the conductive adhesive 80 are continuous, and as a result, the cap can be led to the ground potential. If no problem occurs even if the binder in the conductive adhesive is made of an organic binder, it may be used.

As the organic sealing agent of this type, a polyimide-based sealing agent and an epoxy-based sealing agent are preferable. A polyimide-based material is preferably a conductive polyimide encapsulant containing silver particles, as a general property, can be cured at about 150 ° C. to 300 ° C., and a use temperature range is −55 ° C. to 35 ° C.
° C, the maximum continuous use temperature is about 200 ° C, and the die shear adhesive strength is 205 kg at 25 ° C and 170 kg at 150 ° C, respectively.
Approximately 150 kg at 300 ° C. and 70 kg at 350 ° C. can be realized.

The volume resistivity formed at a sufficiently high density can realize about 0.0001 to 0.0002 Ωcm. Accordingly, when the die shear strength and the volume resistivity are at this level, the electronic element piece, which is the object of the present invention, can be effectively shielded from an external electromagnetic field.

With this level of mechanical strength, it has sufficient strength for surface mounting on a printed circuit board, and is put in a high-temperature furnace together with other electronic parts and the like, and is subjected to soldering and other processes. There is no particular problem when passing through. The properties of the epoxy-based sealant are basically the same as those of the polyimide-based sealant.
Is smaller than a polyimide-based sealant and generally has the following characteristics.

That is, the curing conditions are about 120 ° C. to 200 ° C., the operating temperature range is about −55 ° C. to 150 ° C., and the die shear adhesive strength is 380 kg at 25 ° C. and 150 ° C., respectively.
84 kg and 35 kg at 350 ° C. Further, since it is formed at a sufficiently high density, the volume resistivity is as low as about 0.0002 Ωcm. Such an organic conductive adhesive is arranged on a predetermined portion of a ceramic base of a ceramic package made of a ceramic body by a method such as screen printing, dispenser or stamping. It goes without saying that the cap may be arranged at the portion where the metal thin film of the cap is formed, without being arranged at the ceramic base.

Next, the third aspect of the present invention will be described. According to a third aspect of the present invention, as described above, the cap is made of a metal material or a conductive ceramic material.
It is di. As a material for the conductive cap, a metal material will generally be conceived, but it is also possible to use a conductive material which is a ceramic material other than the metal material.

When a conductive ceramic material is used as described above, the shape of the cap is relatively easy to process, and for example, a bulky cap 92 as shown in FIG. 9 is possible. When it is necessary to protect the electronic element piece 93 with the cap 92, the electronic element piece 93 is vertically arranged as shown in FIG. 9, and the entire electronic element piece 93 is housed by the cap 92. Such an electronic element sealing package 90 may be used.

Next, the invention according to claim 4 will be described. According to a fourth aspect of the present invention, as described above, the ceramic base contains forsterite in a glass of 30 to 70 watts.
The electronic device sealing package according to claim 1, wherein the cap is made of a glass-ceramic composite material having a thermal expansion coefficient of 100 to 150 × 10 ⁻⁷ dispersed therein by t%, and the cap is made of a nickel-iron alloy. The feature of the invention according to claim 4 is that the so-called glass-ceramic composite material is used as the ceramic base material and the nickel-iron alloy is used as the material of the cap.

As described above, since the thermal expansion coefficient can be made relatively high by using the glass ceramic material, it becomes possible to match the thermal expansion coefficient of this ceramic base to, for example, the thermal expansion coefficient of a quartz resonator element. Also, when a nickel-iron alloy is used as the material of the cap, the electromagnetic shielding performance is extremely high, so that even when a thin cap is used, effective electromagnetic shielding performance can be ensured.

Next, the invention according to claim 5 will be described. According to a fifth aspect of the present invention, as described above, there is provided an electronic element sealing structure in which a cap made of a conductive material is placed on a ceramic base on which a quartz resonator element is disposed.
Is forsterite in glass 30-70wt%
The cap is made of a dispersed glass-ceramic composite material having a coefficient of thermal expansion of 100 to 150 × 10 ⁻⁷ , the cap is made of an iron-nickel alloy, and a metal thin film made of gold or / and silver is formed on the surface. The cap is attached to the ceramic base by arranging a conductive adhesive on the ceramic base, and the electronic element seal capable of guiding the cap to the ground potential through the ground electrode of the ceramic base. It is a stop structure.

The invention according to claim 5 is a more specific example of the invention according to claim 4, and when a glass-ceramic composite material containing forsterei is used as a base, a quartz oscillator is most suitable. For this reason, the present invention is limited to the ceramic base on which the quartz oscillator pieces are arranged.

Next, the invention according to claim 6 will be described. The invention according to claim 6 is as described above in claim 1 or 2
An electronic element sealing structure in which a piezoelectric material element piece is sealed as the electronic element in the electronic element sealing package according to any one of the above. The invention of claim 6 claims the invention of claim 1 or 2 in which an actual electronic element piece is sealed to form an electronic element sealing structure.

Next, the invention according to claim 7 will be described. The invention according to claim 7 is the electronic element sealing structure according to claim 5, wherein the base is substantially rectangular as described above, and the substantially rectangular electronic element is fixed at both ends in the longitudinal direction.
In the case where the electronic element arranged on the ceramic base is fixed at both ends in this way, that is, as shown in FIG. 11, when the electronic element sealing structure is actually subjected to a heating step, The thermal stress generated in the internal electronic element becomes a problem. That is, since the thermal expansion coefficient is generally different from that of the electronic element piece and that of the ceramic base, thermal stress is applied to the electronic element piece due to the difference in the coefficient of thermal expansion.

Since this thermal stress has an adverse effect on the electronic element piece, the thermal stress should be as small as possible. Therefore, a glass-ceramic composite was used as such a ceramic-based material as described above. When the glass-ceramic composite is used in this manner, even if the electronic element sealing package 100 has the electronic element pieces 102 fixed at both ends as shown in FIG.
Since the thermal expansion coefficients of the ceramic element and the ceramic base 101 match, no thermal stress is applied to the electronic element piece 102 more than necessary, and even with such an electronic element piece fixing method, It has the feature that the performance of is not impaired.

Next, the invention according to claims 8 and 9 will be described. In the invention according to claim 8, as described above, an oxide film is formed on the surface of the cap.
4. The package for sealing an electronic element according to any one of 4. The invention according to claim 9 is the electronic element sealing structure according to any one of claims 5 to 7, wherein an oxide film is formed on the surface of the cap as described above. Even if an oxide film is formed on the surface of the cap in this way, by forming a metal thin film thereon, the uneven distribution of metal particles contained in the conductive adhesive is prevented, and the gap between the cap and the ground electrode of the ceramic package is reduced. A low resistance value between them can be realized.

Therefore, even when an oxide film is formed on the surface of the cap as described in claim 8 or 9, an electronic element sealing structure or an electronic element sealing structure having a sufficient electromagnetic shielding effect. Package can be realized. In particular, when it is necessary to form an oxide film on the surface of the cap, for example, when an oxide film is formed to protect the metal cap or the conductive cap from the external environment, the surface of the cap is oxidized. It is essential that the electromagnetic shielding performance is not impaired even in such a case, which is a feature of the invention according to claim 8 or claim 9.

[0068]

As described above, according to the first to ninth aspects of the present invention, a cap made of a conductive material is sealed on a ceramic base, and in particular, the cap is made conductive with respect to the ground electrode of the ceramic base. Since a thin metal film is formed on the cap when sealing with an adhesive, a very small connection resistance can be realized, and sufficient electromagnetic shielding can be realized. Also, since the electronic element piece is sealed on the ceramic base, there is no problem of heat, and an excellent electronic element in which thermal stress does not accumulate in the electronic element piece housed therein by adjusting to a specific coefficient of thermal expansion. A sealing package and an electronic element sealing structure are realized.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of an embodiment of an electronic element sealing package of the present invention.

FIG. 2 is a partially cutaway perspective view of another embodiment of the electronic device sealing package of the present invention.

FIG. 3 is a perspective view showing a state in which the electronic element sealing structure of the present invention is disposed on a printed circuit board.

FIG. 4 is a side sectional view showing another embodiment of the electronic device sealing package of the present invention.

FIG. 5 is a manufacturing process diagram of a ceramic base.

FIG. 6 is a process chart for integrating green sheets.

FIG. 7 is a conceptual diagram showing a configuration of a conductive adhesive.

FIG. 8 is a conceptual diagram showing a mechanism for conducting a conductive adhesive.

FIG. 9 is an exploded perspective view of an electronic element sealing package showing the storage of electronic element pieces by a bulky cap.

FIG. 10 is a front view showing thermal stress when an electronic element piece is fixed at both ends.

FIG. 11 is a side sectional view of a conventional semiconductor device.

FIG. 12 is an exploded perspective view of a conventional electronic element sealing package.

[Explanation of symbols]

 10, 20; package for electronic element sealing 31 electronic element sealing structure 41a, 41b, 91, 101 ceramic base 42a, 42b, 92 cap 42af, 42bf metal thin film 14, 44a, 44b conductive adhesive 45a, 45b ground electrode 72,82 conductive particles

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Eigo Kishi, Inventor 2-9-1, Hararashi, Otsu-shi, Shiga Prefecture Kansai Nippon Electric Co., Ltd. F-term (reference) 5J033 GG03 GG08 GG14 GG15 KK04

Claims (9)

[Claims] An electronic device sealing package comprising a ceramic base covered with a cap made of a conductive material,
A metal thin film made of gold or / and silver is formed on the surface of the cap, a conductive adhesive is disposed on a portion where the metal thin film is formed, and the cap is attached on the ceramic base. An electronic element sealing package capable of guiding the cap to a ground potential via a ground electrode of the ceramic base. 2. The electronic device sealing package according to claim 1, wherein the conductive adhesive is a conductive glass in which conductive particles made of a metal material are dispersed in a glass component. 3. The package according to claim 1, wherein the cap is made of a metal material or a conductive ceramic material. 4. The ceramic base is made of a glass-ceramic composite material having a thermal expansion coefficient of 100 to 150 × 10 ⁻⁷ in which forsterite is dispersed in a glass by 30 to 70% by weight, and the cap is made of a nickel-iron alloy. The package for sealing an electronic element according to claim 1 or 2. 5. An electronic element sealing structure in which a cap made of a conductive material is covered on a ceramic base on which a quartz-crystal vibrating piece is arranged, wherein said ceramic base contains forsterite in glass. The cap is made of a glass-ceramic composite material having a thermal expansion coefficient of 100 to 150 × 10 ⁻⁷ dispersed in an amount of about 70 wt%, and the cap is made of an iron-nickel alloy, and a metal thin film made of gold or / and silver is formed on the surface. The cap can be attached to the ceramic base by arranging a conductive adhesive on the portion where the ceramic base is formed, and the cap can be led to the ground potential through the ground electrode of the ceramic base. Electronic element sealing structure. 6. An electronic element sealing structure in which a piezoelectric material element piece is sealed as the electronic element in the electronic element sealing package according to claim 1. 7. The electronic element sealing structure according to claim 5, wherein the base is substantially rectangular, and a substantially rectangular electronic element is fixed at both ends in the longitudinal direction. 8. The package for sealing an electronic element according to claim 1, wherein an oxide film is formed on a surface of said cap. 9. The electronic element sealing structure according to claim 5, wherein an oxide film is formed on a surface of said cap.