JP2002151613A - Package for accommodating semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem where destruction of bonding which is caused by thermal stress or mechanical impact from the outside can not be prevented effectively in a package for accommodating a semiconductor element. SOLUTION: This package for accommodating a semiconductor element consists of an insulating base substance 1 having a mounting part 1a of a semiconductor element 7 on an upper surface, a frame body 2 which is bonded on an upper surface of the insulating base substance 1 so as to surround the mounting part 1a, and a metal lid body 3 of an almost flat plate type which is bonded on an upper surface of the frame body 2 via sealing agent 4. In the metal lid body 3, a protruding part 3a having slopes wherein an angle of inclination to a flat part of a lower surface is 30-85 deg. and height is 0.02-0.25 mm is formed on an inner wall side of the frame body 2, along a part position facing an aperture of the frame body 2 on a lower surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device storage package for protecting a semiconductor device from external mechanical shock or moisture intrusion, and more particularly to a portable telephone equipped with a high frequency semiconductor device. The present invention relates to a semiconductor element storage package used for a typical mobile communication device.

[0002]

2. Description of the Related Art In recent years, the size and weight of mobile communication devices have been rapidly reduced, and accordingly, the size of semiconductor device storage packages for hermetically sealing semiconductor devices to be mounted has been reduced.

Such a package for housing a semiconductor element is generally made of an electrically insulating material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, and a silicon nitride sintered body. An insulating substrate having a mounting portion for the semiconductor element, a frame joined to the upper surface of the insulating substrate so as to surround the mounting portion, and a substantially flat lid joined to the upper surface of the frame by solder, brazing material, or the like; It is composed of In addition, as the material of the lid, a metal such as an iron-nickel-cobalt alloy that can be thinned is used in accordance with the reduction in the size and weight of the semiconductor element housing package.

However, in such a package for accommodating a semiconductor element, the frame and the metal lid having different coefficients of thermal expansion are made of a metal such as solder or brazing material having a high elastic modulus and being difficult to relieve stress such as distortion. Due to the bonding, heat generated when the semiconductor element operates causes a large stress between the frame and the metal lid, and this stress acts on the frame to crack the frame. And as a result,
There is a disadvantage that the hermetic sealing of the container is broken and the semiconductor element contained therein cannot be operated normally and stably for a long period of time.

On the other hand, there has been proposed a method of joining a frame and a metal lid with a resin adhesive having a low elastic modulus. According to this proposal, for example, a thermosetting epoxy resin is applied to the joint between the frame and the metal lid using a screen printing method or a dispenser method, and the joint between the frame and the metal lid is coated. The frame and the metal lid are joined by pressurizing and heating, so that the heat generated when the semiconductor element operates causes a difference in thermal expansion coefficient between the frame and the metal lid. Even if a large stress is generated, the resin adhesive having a low elasticity can relieve the stress and effectively prevent the frame from cracking.

[0006]

However, in such a bonding with a resin adhesive, the bonding between the metal lid and the resin adhesive is only an anchoring effect due to fine irregularities on the surface, so that a recent semiconductor device is used. With a sealing design in which the joint area between the frame and the metal lid is reduced in accordance with the miniaturization of the device, sufficient joint strength cannot be obtained, and the heat generated when the semiconductor element operates causes the thermal expansion coefficient to decrease. The joint between the metal lid and the resin adhesive is broken due to the large stress generated between different frames and the metal lid or the mechanical shock during assembly after the secondary mounting, and the airtight reliability of the container However, there is a problem that the temperature is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to effectively prevent joint breakage due to thermal stress or external mechanical shock.
Another object of the present invention is to provide a package for housing a semiconductor element having high airtight reliability.

[0008]

A package for accommodating a semiconductor device according to the present invention comprises an insulating base having a mounting portion for a semiconductor element on an upper surface, and a frame joined to the upper surface of the insulating base so as to surround the mounting portion. A substantially flat metal lid joined to the upper surface of the frame via a sealant, wherein the metal lid faces the opening of the lower frame. Along the inner wall side of the frame along the part to be inclined, the inclination angle with respect to the flat part of the lower surface is 30 ~ 85 °, the height is 0.02 ~ 0.25
A protrusion having an inclination of mm is formed.

According to the semiconductor device housing package of the present invention, the inclination angle with respect to the flat portion of the lower surface is formed on the inner wall side of the frame along the portion of the lower surface of the metal lid facing the opening of the frame.
Since a projection having a slope of 30 to 85 ° and a height of 0.02 to 0.25 mm was formed, when the frame body and the metal lid were joined, the gap between the sealant and the metal lid was Adhesive force against shear force in the shear direction is applied, and the mechanical shock from the outside is effectively dispersed at the projections, so that the joining becomes very strong, resulting in thermal stress or mechanical stress from the outside. It is possible to provide a package for housing a semiconductor element having good airtight reliability, in which the joint between the frame and the metal lid hardly breaks due to an impact.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a package for accommodating a semiconductor device according to the present invention.

FIG. 1 is a sectional view showing an example of an embodiment of a package for housing a semiconductor element according to the present invention, and FIG. 2 is a sectional view of a main part of FIG. In these figures, 1 is an insulating base, 2 is a frame, 3 is a metal lid, 3a is a protrusion, and 4 is a sealant. These mainly constitute a semiconductor element housing package of the present invention. You.

The insulating base 1 is provided with a mounting portion 1a for mounting the semiconductor element 7 substantially at the center of the upper surface thereof, and the semiconductor element 7 is made of glass, resin, brazing material or the like on the mounting portion 1a. It is bonded and fixed via an adhesive. A frame 2 is joined to the upper surface of the insulating base 1 so as to surround the mounting portion 1a.

The insulating base 1 and the frame 2 are made of aluminum oxide sintered body, mullite sintered body, aluminum nitride sintered body, silicon nitride sintered body, silicon carbide sintered body or the like. If it is made of an electrically insulating material, for example, if it is made of an aluminum oxide sintered body, an appropriate organic binder, solvent, plasticizer, and dispersant are added to the raw material powder such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide. The mixture is added and mixed to form a slurry, and the slurry is formed into a sheet by using a conventionally known sheet forming method such as a doctor blade method or a calendar roll method to obtain a ceramic green sheet (ceramic green sheet). The ceramic green sheet is manufactured by performing an appropriate punching process, laminating a plurality of the sheets, and firing at a high temperature of about 1600 ° C.

A plurality of wiring conductor layers 5 are formed on the insulating base 1 from the periphery of the mounting portion 1a to the lower surface thereof, and the semiconductor element 7 is provided around the mounting portion 1a of the wiring conductor layer 5. Each electrode is electrically connected via a bonding wire 8, and an external electric circuit (not shown) is electrically connected to a portion led out to the lower surface of the insulating base 1 via a connection member such as solder. Is done.

The wiring conductor layer 5 functions as a conductive path for electrically connecting each electrode of the semiconductor element 7 to an external electric circuit. For example, an organic solvent suitable for a high melting point metal powder such as tungsten, molybdenum, and manganese is used. A metal paste obtained by adding and mixing a solvent, a plasticizer, and the like is printed and applied in advance to a ceramic green sheet serving as an insulating substrate 1 by using a conventionally known thick film method such as a screen printing method, and the ceramic paste is applied to the ceramic paste. By firing at the same time as the green sheet, a predetermined pattern is formed from the periphery of the mounting portion 1a of the insulating base 1 to the lower surface.

The surface of the wiring conductor layer 5 is coated with a metal such as nickel or gold having good conductivity, good corrosion resistance and good wettability with a brazing material to a thickness of 1 to 20 μm by plating. In addition, it is possible to effectively prevent the oxidative corrosion of the wiring conductor layer 5 and to strengthen the connection between the wiring conductor layer 5 and the bonding wires 8 and the soldering between the wiring conductor layer 5 and the wiring conductor of the external electric circuit. Can be. Therefore, in order to prevent the oxidative corrosion of the wiring conductor layer 5 and to make the connection between the wiring conductor layer 5 and the bonding wire 8 and the soldering between the wiring conductor layer 5 and the wiring conductor of the external electric circuit strong, It is preferable that nickel, gold or the like is applied to the surface of the layer 5 by plating so as to have a thickness of 1 to 20 μm.

A metal lid 3 is joined to the upper surface of the frame 2 via a sealant 4. The metal lid 3 has a function of hermetically sealing the semiconductor element 7 inside the package and has a function of preventing the semiconductor element 7 from being broken by an external impact. It is formed of a metal material such as tungsten, iron-nickel alloy, iron-cobalt alloy, iron-nickel-cobalt alloy.

In the package for accommodating a semiconductor element of the present invention, the inclination angle α with respect to the flat portion of the lower surface is formed on the inner wall side of the frame 2 along the portion of the lower surface of the metal lid 3 facing the opening of the frame 2. It is important to form a projection 3a having a slope of 30 to 85 ° and a height of 0.02 to 0.25 mm.

According to the semiconductor element housing package of the present invention, the inclination angle of the lower surface with respect to the flat portion of the lower surface is formed on the inner wall side of the frame 2 along the portion of the lower surface of the metal cover 3 facing the opening of the frame 2. [alpha] is 30 to 85 [deg.] and the height is 0.02 to 0.25 mm. Since the projection 3a having a slope is formed, the adhesive force between the sealing agent 4 and the metal lid 3 against the shearing shear force is applied. And the mechanical shock from the outside is effectively dispersed at the projections 3a. As a result, the joint failure between the frame 2 and the metal lid 3 occurs due to thermal stress or mechanical shock from the outside. It is difficult to provide a package for housing a semiconductor element which is difficult and has good airtight reliability.

When the inclination angle α of the projection 3a is less than 30 °, the joining strength against the shearing shear force becomes weak when an external force in the direction of peeling the metal lid 3 from the frame 2 is applied. In addition, there is a tendency that the joining strength between the metal lid 3 and the frame 2 does not improve. Also, the inclination angle α of the projection 3a is
When the angle exceeds 85 °, the stress between the sealant 4 and the metal lid 3 tends to concentrate on the inclined portion, and the mechanical shock from the outside tends not to be effectively dispersed at the protrusion 3a. is there. Therefore, it is preferable that the inclination angle α of the projection 3a with respect to the flat portion of the metal lid 3 be in the range of 30 to 85 °.

When the height of the projection 3a is less than 0.02 mm, the height of the projection 3a is substantially the same as the thickness of the sealant 4 described later, and it tends to be difficult to effectively disperse the stress. If the thickness exceeds 0.25 mm, in a general thin semiconductor device, there is a risk of short-circuit due to contact with the bonding wire 8. Therefore, the height of the projection 3a is 0.
It is preferably in the range of 02 to 0.25 mm.

The protruding portion 3a is provided in a shape having a slope on the inner wall side of the frame 2 along a portion of the lower surface of the metal lid 3 opposed to the opening of the frame 2. It is preferable to form it near the inner wall of the frame 2 so that the liquid pool 9 of the sealant 4 is formed between the portions 3a.

The projection 3a may have a trapezoidal shape as shown in FIG. 1 or another shape such as a frame shape, and is frame-shaped from the viewpoint of reducing the weight and thickness of the metal lid 3. Is particularly preferred.

Various shapes such as a triangle and a trapezoid are used for the cross-sectional shape of the frame-shaped protrusion 3a. Further, as shown in the main part cross-sectional views of the metal lid 3 in FIGS. Projection 3
It may be trapezoidal / arc-shaped having a concave portion on the side opposite to a.

When such a metal lid 3 is made of, for example, an iron-nickel alloy, an ingot (lump) of an iron-nickel alloy rolled into a plate shape is formed in a shape corresponding to a predetermined projection shape. In addition to press-molding with a press die manufactured in this way, it is formed into a predetermined size by a conventionally known punching method. Alternatively, it is also possible to form the projections 3a and form them into predetermined outer dimensions by chemical etching.

The metal lid 3 is made of an iron-nickel alloy.
When made of an iron alloy such as an iron-cobalt alloy or an iron-nickel-cobalt alloy, the surface of the metal lid 3 may be coated with various metal platings such as nickel, gold, and solder to prevent corrosion. preferable.

The sealant 4 comprises the frame 2 and the metal lid 3.
And has a function of bonding with a glass, a resin adhesive, a brazing material, or the like.

The sealant 4 is preferably a resin adhesive having low elasticity from the viewpoint of stress relaxation, and a conventionally well-known screen printing method or the like is employed for the joint of the frame 2 or the metal lid 3. After the printing and application, the frame 2 and the metal lid 3 can be firmly joined by heating and drying, and by superimposing and pressurizing and heating the joined portions.

The thickness of the sealing agent 4 after curing is preferably in the range of 1 to 50 μm, and if it is less than 1 μm, the stress relaxation tends to be ineffective, and if it exceeds 50 μm, the sealing agent 4 increases, and the semiconductor element 7 tends to be easily deteriorated by moisture. Therefore, the sealant 4
Is preferably in the range of 1 to 50 μm after curing.

As such a sealant 4, a thermosetting epoxy resin adhesive having a dense three-dimensional network structure is particularly preferable from the viewpoint of moisture resistance or bonding strength, and bisphenol A type epoxy resin and bisphenol A A-modified epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, special novolak type epoxy resin, phenol derivative epoxy resin, biphenol skeleton type epoxy resin, etc. What added the hardening | curing agent of phosphorus type | system | group, hydrazine type | system | group, imidazole adduct type | system | group, amine adduct type | system | group, cationic polymerization type | system | group, dicyandiamide type | system | group, etc. is used.

Incidentally, two or more kinds of epoxy resins may be used as a mixture, and the elastic modulus of the epoxy resin adhesive can be further reduced by adding soft fine particles. Such soft fine particles include, for example, silicone rubber, silicone resin, LDPE, HDP
Plastic powders such as E • PMMA • crosslinked PMMA • polystyrene • crosslinked polystyrene • ethylene-acrylic copolymer • polyethyl methacrylate • butyl acrylate • urethane are used.

In addition, the sealing material 4 contains a conductive filler and is formed on the insulating substrate 1 so as to surround the mounting portion 1a on the upper surface of the frame 2 as shown in the sectional view of FIG. By forming a frame-shaped conductor layer 6 that is electrically connected to the wiring conductor layer 5, the metal lid 3 and the wiring conductor layer 5 are electrically connected to each other, and a shield that prevents electromagnetic wave radiation to the outside. It is possible to obtain a semiconductor element housing package that can obtain good effects and an immunity effect of preventing invasion of electromagnetic waves from the outside.

The frame-shaped conductor layer 6 is formed by adding a suitable organic solvent, a solvent, a plasticizer, etc. to a high melting point metal powder such as tungsten, molybdenum, manganese, etc. and mixing the paste with a conventionally known screen printing method or the like. A thick film method is employed to print and coat the ceramic green sheet to be the frame 2 in advance, and this is baked at the same time as the ceramic green sheet, thereby forming a predetermined pattern on the upper surface of the frame 2.

Examples of the conductive filler contained in the sealant 4 include various resins such as acrylic resin, phenol resin, urethane resin, benzoguanamine resin, melamine resin, polydivinylbenzene, and polystyrene resin. Particles having an organic resin material as a core and a surface layer coated with a conductive material such as nickel, gold, silver, or copper, carbon powder, or metal powder such as nickel, gold, silver, copper, or solder are used.

The conductive filler preferably contains 0.5 to 200% by weight of a filler having an average particle size of 0.1 to 30 μm. Therefore, the electrical connection between the metal lid 3 and the frame-shaped conductor layer 6 tends to be difficult, and when the thickness exceeds 30 μm, the conductive particles are greatly deformed by the load when heated and cured while applying pressure. As a result, there is a tendency that the metal coating is broken and good conductivity cannot be obtained. Therefore, the average particle size of the conductive filler is preferably in the range of 0.1 to 30 μm.

Further, when the content of the conductive filler is less than 0.5% by weight, the conductivity of the sealant 4 tends to decrease, and when it exceeds 200% by weight, the wettability of the sealant 4 is reduced. Tends to decrease. Therefore, the content of the conductive filler is preferably in the range of 0.5 to 200% by weight.

Thus, according to the package for housing a semiconductor element of the present invention, the mounting portion 1a of the insulating base 1 having the frame 2
The semiconductor element 7 is bonded and fixed via an adhesive made of glass, resin, brazing material, or the like, and each electrode of the semiconductor element 7 is connected to the wiring conductor layer 5 by a bonding wire 8. The lid 3 is connected via a sealant 4 and the semiconductor element 7 is hermetically accommodated in a container formed of the insulating base 1, the frame 2 and the metal lid 3, thereby providing a final product. The semiconductor device is completed.

It should be noted that the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the spirit of the present invention. May be electrically connected by a conductive connection member such as a solder bump.

[0039]

According to the semiconductor device housing package of the present invention, the inclination angle of the lower surface with respect to the flat portion is formed on the inner wall side of the frame along the portion of the lower surface of the metal lid facing the opening of the frame. Since a projection having a slope of 30 to 85 ° and a height of 0.02 to 0.25 mm was formed, when the frame body and the metal lid were joined, the gap between the sealant and the metal lid was Adhesive force against shear force in the shear direction is applied, and the mechanical shock from the outside is effectively dispersed at the projections, so that the joining becomes very strong, resulting in thermal stress or mechanical stress from the outside. It is possible to provide a package for housing a semiconductor element having good airtight reliability, in which the joint between the frame and the metal lid hardly breaks due to an impact.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of an embodiment of a semiconductor element storage package according to the present invention.

FIG. 2 is a cross-sectional view of a main part of the package for housing a semiconductor element shown in FIG. 1;

FIG. 3 is a cross-sectional view of a main part showing another embodiment of the metal lid in the semiconductor element housing package of the present invention.

FIG. 4 is a cross-sectional view of a main part showing still another embodiment of the metal lid in the semiconductor element housing package of the present invention.

FIG. 5 is a cross-sectional view showing another embodiment of the semiconductor device housing package of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating base 1a ... Mounting part 2 ... Frame body 3 ... Metal lid 3a ... Projection part 4 ... ···· Encapsulant 5 ····· Wiring conductor layer 7 ····· Semiconductor element

Claims (4)

[Claims] 1. An insulating base having a mounting portion for a semiconductor element on an upper surface, a frame joined to the upper surface of the insulating base so as to surround the mounting portion, and an upper surface of the frame via a sealant. A package for a semiconductor element, comprising a substantially flat metal lid to be joined, wherein the metal lid is located on the inner wall side of the frame along a portion of the lower surface facing the opening of the frame. The inclination angle of the lower surface with respect to the flat portion is 30 to 85 °.
And a projection having a height of 0.02 to 0.25 mm with a slope formed therein. 2. The package for accommodating a semiconductor element according to claim 1, wherein said projection is provided in a frame shape. 3. The package according to claim 1, wherein the sealing agent is an epoxy resin adhesive. 4. The package according to claim 3, wherein the epoxy resin adhesive contains a conductive filler.