JP3199672B2 - Electronic component storage package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package for accommodating electronic components such as a semiconductor device, a quartz oscillator, and a surface acoustic wave device.

[0002]

2. Description of the Related Art Conventionally, electronic component housing packages for housing electronic components such as semiconductor elements, quartz oscillators, surface acoustic wave elements, etc. are generally made of an electrically insulating material such as an aluminum oxide sintered body. A ceramic base having a square frame portion on the outer peripheral portion, and tungsten formed on the ceramic base and led out from the inside to the outside of the frame portion,
It consists of a metallized wiring layer made of a high melting point metal powder such as molybdenum and manganese, and a metal lid attached to the upper surface of the frame of the ceramic base and made of an iron-nickel-cobalt alloy or an iron-nickel alloy. An electronic component such as a semiconductor element or a quartz oscillator is accommodated inside the frame of the ceramic base, and each electrode of the electronic component is connected to a predetermined metallized wiring layer via a bonding wire. An electronic device as a final product is obtained by welding a metal lid to the upper surface of the part and hermetically sealing the electronic components inside a container formed of a ceramic base and a metal lid.

The above-mentioned conventional package for housing electronic parts is usually provided with a metal frame made of a metal material such as an iron-nickel-cobalt alloy or an iron-nickel alloy on an upper surface of a frame portion of a ceramic substrate made of an aluminum oxide sintered body. Is previously attached via a brazing material such as silver brazing, and the metal lid is attached to the upper surface of the ceramic base by welding a metal lid to the metal frame by a seam welding method or the like. Thereby, the inside of the container formed of the ceramic base and the metal lid is hermetically sealed.

In order to attach the metal frame to the upper surface of the frame of the ceramic substrate, first, the upper surface of the frame of the ceramic substrate is made of a high melting point metal powder such as tungsten, molybdenum, manganese or the like in an area slightly larger than the metal frame. A rectangular annular metallized metal layer is formed by applying a thick film technique such as a conventionally known screen printing method, and then the surface of the metallized metal layer is plated with nickel, gold or the like by electrolytic plating. After applying a metal layer,
A brazing material such as silver brazing and a metal frame are sequentially placed on the metallized metal layer, and finally a temperature of about 800 ° C. is applied to the brazing material to heat and melt the brazing material.

The plating metal layer made of nickel, gold or the like is deposited on the surface of the metallized metal layer having a rectangular ring shape in order to improve the wettability between the metallized metal layer and the brazing material. One of the metallized metal layers,
Alternatively, the two corners are connected to the metallized wiring layer via a through conductor disposed inside the frame of the ceramic base, and the corrosion resistance of the metallized wiring layer and the electrical contact with the electronic component are formed on the surface of the metallized wiring layer. At the same time nickel or gold etc. for good connectivity is deposited by electrolytic plating, a plating metal layer such as nickel or gold is also deposited on the surface of the metallized metal layer forming a square ring at the same time. I have.

[0006]

However, in the conventional package for housing electronic parts, the metallized metal layer and the metallized wiring layer which form a square ring are one of the metallized metal layers.
One or two of the two corners are connected via a through conductor, so when welding the metal lid to the metal frame, part of the heat generated in the metal frame is passed through the through conductor. The heat distribution flows from the metallized metal layer to the metallized wiring layer and between the part where the through conductor of the metallized metal layer exists and the part where the through conductor does not exist. Large variation occurs in the thermal stress generated between the ceramic substrate and cracks and cracks in the ceramic base due to the variation in the thermal stress, and as a result, the hermetic sealing of the container is broken,
There is a disadvantage that the electronic components housed in the container cannot be operated normally and stably for a long period of time.

The present invention has been devised in view of the above drawbacks, and has as its object to completely hermetically seal a container and to allow electronic components housed inside the container to operate normally and stably for a long period of time. It is an object of the present invention to provide a package for storing electronic components.

[0008]

According to the present invention, there is provided a ceramic substrate having a rectangular frame at the outer peripheral portion of the upper surface, a metallized wiring layer formed on the ceramic substrate, and a ceramic substrate attached to the upper surface of the frame of the ceramic substrate. It comprises a square annular metallized metal layer whose surface is coated with a plated metal layer, a metal frame brazed to the metalized metal layer, and a metal lid welded to the metal frame. The rectangular metallized metal layer is characterized in that its four corners are connected to the metallized wiring layer via through conductors arranged inside the frame.

According to the electronic component housing package of the present invention, since the metallized metal layer and the metallized wiring layer, which form a rectangular ring, are connected via the through conductors at the four corners of the metallized metal layer, the metal frame is formed. When welding the metal lid to the metal frame, even if a part of the heat generated in the metal frame flows from the metallized metal layer to the metallized wiring layer via the through conductor, a large gradient is caused in the heat distribution of the metallized metal layer. However, as a result, the thermal stress generated between the metallized metal layer and the ceramic substrate becomes substantially uniform over the whole, and cracks and cracks are effectively prevented from being generated in the ceramic substrate, and the container is hermetically sealed. It is complete, and the electronic components housed in the container can be operated normally and stably for a long period of time.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the accompanying drawings. FIGS. 1 to 3 show an embodiment in which the electronic component housing package of the present invention is applied to a package housing a semiconductor element. Reference numeral 1 denotes a ceramic base having a rectangular frame portion 2 on the outer periphery of the upper surface; Is a metal lid. The ceramic base 1 having the frame portion 2 and the metal lid 3 constitute a container for accommodating the semiconductor element 4 therein.

A ceramic substrate 1 having a frame portion 2 on the outer peripheral portion of the upper surface includes an aluminum oxide sintered body, a mullite sintered body, an aluminum nitride sintered body, a silicon carbide sintered body,
A mounting portion 1a on which the semiconductor element 4 is mounted is provided at the center of the upper surface of the ceramic base 1 inside the frame portion 2 of the glass ceramic sintered body, and the semiconductor element 4 is mounted on the mounting portion 1a. It is attached via an adhesive such as brazing material, glass, resin, or the like.

When the ceramic substrate 1 having the frame portion 2 on the outer periphery of the upper surface is made of, for example, an aluminum oxide sintered body, a suitable organic solvent or solvent is added to aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, or the like. A green sheet (raw sheet) is formed by mixing into a slurry and employing a well-known doctor blade method or calender roll method. Thereafter, the green sheet is subjected to appropriate punching and It is manufactured by stacking sheets and firing at a high temperature (about 1800 ° C.).

A plurality of metallized wiring layers 5 extending from the inside of the frame portion 2 to the lower surface of the ceramic substrate 1 are formed on the ceramic base 1 so as to be attached to the inside of the frame portion 2 of the metallized wiring layer 5. The electrode of the semiconductor element 4 is electrically connected via a bonding wire 6, and a portion led out to the lower surface of the ceramic base 1 is electrically connected to a wiring conductor (not shown) of an external electric circuit board via solder or the like. Connected.

A plurality of metallized wiring layers 5 provided on the ceramic base 1 are made of a metal powder such as tungsten, molybdenum, manganese or the like. The metallized wiring layers 5 connect each electrode of the semiconductor element 4 to a predetermined external electric circuit. It works to connect to each other.

The metallized wiring layer 5 is formed, for example, by applying a metal paste obtained by adding an organic solvent and a solvent to a metal powder such as tungsten on a green sheet serving as the ceramic substrate 1 in a predetermined pattern by a conventionally well-known screen printing method. By printing and applying, it is attached and derived in a predetermined pattern from the inside of the frame portion 2 to the lower surface of the ceramic base 1.

The metallized wiring layer 5 has a first plated metal layer 10 made of a metal having excellent corrosion resistance such as nickel and gold and a good wettability with a brazing material formed on the exposed outer surface by an electrolytic plating method. The first plated metal layer 10 effectively prevents oxidation corrosion of the metallized wiring layer 5 and connects the metallized wiring layer 5 to the bonding wire 6 to a thickness of 1.0 to 20.0 μm. The connection between the metallized wiring layer 5 and the wiring conductor of the external electric circuit board is made strong.

When the first plating metal layer 10 is formed of, for example, nickel, the metallized wiring is formed in a nickel plating bath composed of 240 g / L of nickel sulfate, 45 g / L of nickel chloride, and 30 g / L of boric acid. After immersing the layer 5, a predetermined electric field required for electrolytic plating is applied to the metallized wiring layer 5,
It is formed by depositing nickel on the surface of the metallized wiring layer 5.

If the thickness of the first plated metal layer 10 is less than 1.0 μm, the corrosion resistance and the wettability of the brazing material of the metallized wiring layer 5 are not significantly improved.
m, a large stress is generated inside the first plating metal layer 10 when the first plating metal layer 10 is formed,
The internal stress makes it easier to peel off from the metallized wiring layer 5. Therefore, it is preferable that the thickness of the first plating metal layer 10 be in the range of 1.0 to 20.0 μm.

A rectangular annular metallized metal layer 7 is formed on the upper surface of the frame 2 of the ceramic base 1 and the rectangular metallized metal layer 7 is disposed inside the frame 2 at four corners. Electrically connected to the metallized wiring layer 5 through the penetrating conductor 12.

The metallized metal layer 7 functions as a base metal layer when a metal frame 8 is brazed and attached to the upper surface of the frame 2 of the ceramic base 1 via a brazing material 9. The metal frame 8 is brazed through the brazing material 9, and the through conductor 12 electrically connects the metallized wiring layer 5 and the metallized metal layer 7 to form the metallized wiring layer 5.
Plating metal layer 10 on the exposed surface of
At the same time, the second plating metal layer 11 is also formed on the exposed surface of the metallized metal layer 7.

The metallized metal layer 7 and the through conductor 12
Is composed of a high melting point metal powder such as tungsten, molybdenum, and manganese. A metal paste obtained by adding a suitable organic solvent and a solvent to the metal powder such as tungsten is mixed with the surface of the green sheet serving as the ceramic substrate 1 and the green sheet. A predetermined thickness and a predetermined pattern are printed and filled in advance in a perforated through hole by a conventionally known screen printing method or the like, thereby forming the ceramic base 1 on the upper surface of the frame 2 and inside the frame 2 respectively.

The through conductor 12 has a diameter of 0.0
If it is about 5 mm to 0.3 mm, and less than 0.05 mm, it is difficult to form a through hole filled with a metal paste to be a through conductor in the ceramic green sheet to be the insulating base 1, and 0.3 mm to 0.3 mm. Is exceeded, when a through-hole is formed in the ceramic green sheet serving as the frame 2 of the insulating base 1, cracks occur in the ceramic green sheet serving as the frame 2, and the container formed of the insulating base 1 and the lid 3 is closed. There is a risk that airtightness will be impaired. Therefore, it is preferable that the diameter of the through conductor 12 be in the range of 0.05 to 0.3 mm.

Further, the metallized metal layer 7 has a second plated metal layer 1 made of nickel, gold or the like on its exposed outer surface.
1 is applied by an electrolytic plating method, and the second plating metal layer 11 functions to improve the corrosion resistance of the metallized metal layer 7 and the wettability of the brazing material.
By 1, the attachment of the metal frame 8 to the metallized metal layer 7 via the brazing material 9 is strengthened.

The second plating metal layer 11 is electrically connected to the metallized metal layer 7 and the metallized wiring layer 5 via a through conductor 12 provided inside the frame 2, and the surface of the metallized wiring layer 5 is formed. Is formed on the surface of the metallized metal layer 7 at the same time when the first plated metal layer 10 is formed by electrolytic plating.

If the thickness of the second plating metal layer 11 is less than 1.0 μm, the corrosion resistance and the wettability of the brazing material of the metallized metal layer 7 are not significantly improved. When the layer 11 is formed, a large stress is generated inside the second plating metal layer 11, and the second plating metal layer 11 is easily peeled off from the metallized metal layer 7 due to the intrinsic stress. Therefore, it is preferable that the thickness of the second plating metal layer 11 be in the range of 1.0 to 20.0 μm.

A metal frame 8 brazed to the metallized metal layer 7 via a brazing material 9 acts as a base metal member when the metal lid 3 is attached to the ceramic base 1, The metal lid 3 is attached to the frame portion 2 of the ceramic base 1 by welding the metal lid 3 to the base member 8 by a seam welding method or the like. In this case, since the metallized metal layer 7 and the metallized wiring layer 5 forming a square ring are connected via the through conductors 12 at the four corners of the metallized metal layer 7, the metal lid 2 is attached to the metal frame 8. At the time of welding, even if a part of the heat generated in the metal frame 8 flows from the metallized metal layer 7 to the metallized wiring layer 5 via the through conductors 12, it does not cause a large gradient in the heat distribution of the metallized metal layer 7. As a result, as a result, the thermal stress generated between the metallized metal layer 7 and the ceramic substrate 1 becomes substantially uniform over the whole, and no cracks or cracks are generated in the ceramic substrate 1.

The metal frame 8 is made of a metal material such as an iron-nickel-cobalt alloy or an iron-nickel alloy. For example, a conventional method such as a rolling method, a press punching method, or the like is applied to an iron-nickel-cobalt ingot. It is formed into a predetermined frame shape by applying a well-known metal working method, and is attached onto the metallized metal layer 7 by a brazing material 9 such as silver brazing.

To attach the metal frame 8 to the metallized metal layer 7, a plate-shaped brazing material 9 and a metal frame 8 are sequentially placed on the metallized metal layer 7, and then this is About 90
This is performed by heating to a temperature of 0 ° C. to melt the brazing material 9.

A brazing material 9 is formed on the metallized metal layer 7.
As shown in FIG. 3, the metal frame 8 attached via
A pool A of the brazing material 9 is formed between the side surface of the metal frame 8 and the upper surface of the metallized metal layer 7, and the pool A of the brazing material 9 allows the metal frame 8 with respect to the metallized metal layer 7. The brazing attachment strength is high.

Further, a metal frame 8 is formed on the metallized metal layer 7.
Is attached through the brazing material 9, the metallized metal layer 7
Brazing material 9 at least 30 μm wide from the outer periphery
When the non-contact region B of the brazing material in which no metal is present is formed, the metal lid 3 is attached to the metal frame 8 brazed to the metallized metal layer 7 adhered to the upper surface of the frame 2 of the ceramic base 1. At the time of attachment by welding, even if only the metal frame 8 is heated to a high temperature, a large stress is generated between the metal frame 8 and the frame 2 of the ceramic base 1 due to the difference in the thermal expansion coefficient between the two. The stress is 30 from the outer periphery of the metallized metal layer 7.
The metallized metal layer 7 does not concentrate on the outer periphery by acting at a distance of at least μm, and as a result, the metallized metal layer 7 is effectively prevented from peeling from the upper surface of the frame 2 of the ceramic base 1 on the outer periphery. Ceramic substrate 1
The metallized metal layer 7 can be firmly adhered to the upper surface of the frame portion 2 and the metal frame 8 can be firmly brazed and attached to the metallized metal layer 7 to completely seal the container tightly. As a result, the semiconductor element 4 housed in the container can be operated normally and stably for a long period of time.

If the non-contact region B of the brazing material is a region having a width of less than 30 μm from the outer periphery of the metallized metal layer 7, it is generated when the metal lid 3 is attached to the metal frame 8 by welding. There is a risk that concentrated stress acts on the outer periphery of the metallized metal layer 7 and the metallized metal layer 7 is separated from the upper surface of the frame portion 2 of the ceramic base 1. Therefore, in order to prevent the metallized metal layer 7 from peeling off from the upper surface of the frame portion 2 of the ceramic base 1, the non-contact region B of the brazing material is formed in a region having a width of at least 30 μm from the outer periphery of the metallized metal layer 7. Preferably.

When the metal frame 8 is brazed to the upper surface of the metallized metal layer 7 via the brazing material 9, the non-contact area B of the brazing material is at least 30 μm from the outer periphery of the upper surface of the metallized metal layer 7. By applying carbon ink or alumina powder paste etc. to the area of width of
Alternatively, after the metal frame 8 is brazed and attached to the upper surface of the metallized metal layer 7 with the brazing material 9, the brazing material 9 applied to the region having a width of at least 30 μm from the outer periphery of the upper surface of the metallized metal layer 7 is replaced with cyan. It can be formed by removing with a cyan brazing material stripping solution containing sodium chloride, potassium cyanide or the like.

Thus, according to the above-described package, the semiconductor element 4 is attached to the mounting portion 1a located inside the frame portion 2 of the ceramic base 1 via an adhesive such as brazing material, glass, resin and the like. 4 is electrically connected to the metallized wiring layer 5 via the bonding wire 6, and then the metal lid 3 is attached to the metal frame 8 brazed on the upper surface of the frame 2 of the ceramic base 1. The semiconductor device 4 is hermetically sealed in a container made of a ceramic base 1 having a frame portion 2 on the outer peripheral portion of the upper surface and a metal lid 3 by welding or the like, thereby providing an electronic device as a final product.

The present invention is not limited to the above-described package, and various modifications can be made without departing from the scope of the present invention. It has been described that the metallized wiring layer 5 derived from the above is directly connected to the wiring conductor of the external electric circuit board, but the external lead terminals are previously brazed to the metallized wiring layer 5 and the external lead terminals are connected to the external electric circuit. By doing so, the electronic components housed inside the container may be connected to an external electric circuit.

[0035]

According to the electronic component housing package of the present invention, the metallized metal layer and the metallized wiring layer, which form a square ring, are connected via the through conductor at the four corners of the metallized metal layer. When welding the metal lid to the frame, even if a part of the heat generated in the metal frame flows from the metallized metal layer to the metallized wiring layer via the through conductor, a large gradient is caused in the heat distribution of the metallized metal layer. As a result, the thermal stress generated between the metallized metal layer and the ceramic substrate is substantially uniform over the whole, and cracks and cracks are effectively prevented from being generated in the ceramic substrate, and the container is hermetically sealed. The electronic components housed inside the container can be normally and stably operated for a long period of time by completely stopping the operation.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment in which an electronic component housing package of the present invention is applied to a package housing a semiconductor element.

FIG. 2 is a plan view of a metallized metal layer of the package shown in FIG.

FIG. 3 is a partially enlarged sectional view of the package shown in FIG. 1;

[Explanation of symbols]

 1 ... Ceramic base 2 ... Frame 3 ... Metal cover 4 ... Semiconductor element (electronic component) 5 ... Metalized wiring layer 7 ... ... metallized metal layer 8 ... metal frame 9 ... brazing material 11 ... second plating metal layer 12 ... penetrating conductor

Claims (1)

(57) [Claims] 1. A ceramic base having a square frame at the outer periphery of an upper surface, a metallized wiring layer formed on the ceramic base, and a plated metal layer adhered on the upper surface of the frame of the ceramic base. A rectangular annular metallized metal layer, a metal frame brazed to the metallized metal layer, and a metal lid welded to the metal frame, wherein the rectangular annular metallized metal layer is Part 4
A package for electronic component storage, wherein a corner is connected to a metallized wiring layer via a through conductor disposed inside a frame portion.