JP2002164455A - Package for storing semiconductor elements - Google Patents

Abstract

(57) Abstract: In a package for housing a semiconductor element, it is possible to effectively prevent a junction from being broken due to deformation of a metal lid during heating. SOLUTION: An insulating base 1 having a concave portion on the upper surface of which a semiconductor element 3 is mounted, and a substantially flat lid 2 bonded to the upper surface of the insulating base 1 via a sealant 4 so as to cover the concave portion. A semiconductor element storage package comprising:
Is formed of a metal plate by a rolling method, and has a length X in a portion facing the opening of the concave portion, substantially parallel to the rolling direction (AB).
Is not less than 3/5 of the length of the lid 2 in the rolling direction (AB) and not more than the length of the opening of the concave portion, and the height is less than the thickness of the flat plate portion.
A package for accommodating a semiconductor element, wherein a projection 2a having a size of 0.2 to 1.5 times is formed.

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 soldering or brazing material; 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 housing a semiconductor element, a frame and a 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. As a result, the hermetic sealing of the container is broken, and there has been a problem that 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 joining with a resin adhesive, the joining between the metallic lid and the resin adhesive is only an anchoring effect due to fine irregularities on the surface. The sealing design, in which the joint area between the frame body and the metal lid body is reduced in accordance with the miniaturization, does not provide sufficient joint strength, and in particular, a metal plate formed by a rolling method is used as the lid body. In this case, the residual strain stress in the rolling process of the metal material is released by heat generated when the semiconductor element operates or heat of the reflow furnace following the secondary mounting, and the lid is largely warped, and as a result, the lid is And the resin adhesive is broken, and the hermetic reliability of the container is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to effectively prevent joint failure due to deformation of a metal lid during heating and to achieve airtight reliability. An object of the present invention is to provide a high package for housing a semiconductor element.

[0008]

According to the present invention, there is provided a package for housing a semiconductor element, comprising an insulating base having a concave portion on which a semiconductor element is mounted on an upper surface, and a sealing agent interposed on the upper surface of the insulating base so as to cover the concave portion. A package having a substantially flat plate-shaped lid joined thereto, wherein the lid is formed of a metal plate formed by a rolling method, and is substantially parallel to the rolling direction at a portion facing the opening of the concave portion. The length is not less than 3/5 of the length of the lid in the rolling direction and not more than the length of the opening of the recess, and the height is 0.2 to 1.5 times the thickness of the flat plate portion. It is assumed that.

According to the semiconductor device housing package of the present invention, the length of the cover made of a metal plate formed by a rolling process is set substantially parallel to the rolling direction at a portion facing the opening of the concave portion of the insulating base. Is 3/3 of the length of the lid in the rolling direction.
The heat generated when the semiconductor element is operated or the reflow after the secondary mounting is formed because the protrusion having a height of not less than 5 and not more than the length of the opening of the concave portion and having a height of 0.2 to 1.5 times the thickness of the flat plate portion is formed. Even if the strain stress remaining in the rolling process of the metal material is released due to the heat of the furnace or the like, the projection of the lid suppresses the deformation of the lid, and the lid does not warp significantly. The bonding between the body and the resin adhesive is not broken, and the hermetic reliability of the package is not reduced.

[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.

FIGS. 1 and 2 are cross-sectional views showing an example of an embodiment of a semiconductor device housing package according to the present invention.
FIG. 2 is a cross-sectional view in the width direction of the protrusion of the metal lid, and FIG. 2 is a cross-sectional view in the length direction of the protrusion. In these figures,
1 is an insulating substrate, 2 is a lid, 2a is a protrusion, and 4 is a sealant, and these mainly constitute a semiconductor element housing package of the present invention.

The insulating base 1 is provided with a concave mounting portion 1a for mounting the semiconductor element 3 substantially at the center of the upper surface thereof, and the semiconductor element 3 is formed of glass on the bottom surface of the mounting portion 1a.
It is bonded and fixed via an adhesive made of resin, brazing material, or the like.

The insulating substrate 1 is made of an electrically insulating material such as a sintered body of aluminum oxide, a sintered body of mullite, a sintered body of aluminum nitride, a sintered body of silicon nitride, or a sintered body of silicon carbide. For example, in the case of an aluminum oxide-based sintered body, a suitable organic binder, a solvent, a plasticizer, and a dispersant are added to and mixed with raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide. A slurry is formed, and the slurry is formed into a sheet by using a sheet forming method such as a doctor blade method or a calendar roll method, which is well known, to obtain a ceramic green sheet (ceramic green sheet). It is manufactured by performing an appropriate punching process, laminating a plurality of these, 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 bottom surface to the lower surface of the mounting portion 1a. The semiconductor element 3 is provided on the bottom surface of the mounting portion 1a of the wiring conductor layer 5. Are electrically connected via bonding wires 7, 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 connecting member such as solder. Connected.

The wiring conductor layer 5 functions as a conductive path when each electrode of the semiconductor element 3 is electrically connected 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 simultaneously with the green sheet, a predetermined pattern is formed from the vicinity 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 7 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 7 and the soldering between the wiring conductor layer 5 and the wiring conductor of the external electric circuit strong, the wiring conductor Nickel, gold, etc. are plated on the surface of layer 5 by plating.
It is preferred that it is applied to a thickness of 2020 μm.

A lid 2 is bonded to the upper surface of the insulating base 1 via a sealant 4. The lid 2 has a function of hermetically sealing the semiconductor element 3 inside the package and has a function of preventing the semiconductor element 3 from being destroyed by an external impact. It is formed by rolling a metal material such as an iron-nickel alloy, an iron-cobalt alloy, and an iron-nickel-cobalt alloy.

In the package for accommodating a semiconductor element of the present invention, as shown in a plan view of FIG. The length X is substantially parallel to the rolling direction (AB).
It is important to form a projection 2a whose height is not less than 3/5 of the length of the lid 2 in the rolling direction and not more than the length of the opening of the concave portion, and whose height is 0.2 to 1.5 times the thickness of the flat plate portion.

According to the package for housing semiconductor elements of the present invention, the rolling direction (A-
Substantially in parallel with B), the length X is not less than 3/5 of the length of the lid in the rolling direction (AB) and not more than the length of the opening of the recess,
Since the protruding portion 2a having a height of 0.2 to 1.5 times the thickness of the flat plate portion is formed, the metal material is rolled by the heat generated when the semiconductor element 3 operates or the heat of the reflow furnace following the secondary mounting. Even when the remaining strain stress is released, the projection 2a of the lid 2 suppresses the deformation of the lid 2, and the lid 2 does not warp significantly. As a result, the lid 2 and the sealant There is no possibility that the connection with the container 4 is broken and the airtight reliability of the container is reduced.

It should be noted that the length X of the projection 2a is in the rolling direction (A
In the case where the length of the lid 2 in −B) is less than ／, the strength for suppressing deformation of the lid 2 in the rolling direction (AB) is insufficient,
The peeling force due to the warpage of the lid 2 between the insulating base 1 and the lid 2 acts, and the bonding between the insulating base 1 and the lid 2 tends to be easily broken. When the length X of the protrusion 2a exceeds the length of the opening of the concave portion, the protrusion 2a
And the lid 2, it is difficult to make the thickness of the sealing agent 4 described later to an appropriate thickness, the amount of moisture permeation of the sealing agent 4 increases, and the semiconductor element 3 It tends to deteriorate due to moisture. Therefore, the length X of the projection 2a
Is preferably in the range of not less than 3/5 of the length of the lid 2 in the rolling direction (AB) and not more than the length of the opening of the concave portion.

When the height of the projection 2a is less than 0.2 times the thickness of the flat plate of the lid 2, the rolling direction (A-
The strength for suppressing the deformation of B) is insufficient, and the peeling force due to the warpage of the lid 2 acts between the insulating base 1 and the lid 2, and the joint between the insulating base 1 and the lid 2 is easily broken. If it exceeds 1.5 times, distortion in the direction perpendicular to the rolling direction (A-B) remains during the formation of the projections 2a, or warpage tends to occur. As a result, secondary mounting And the like, there is a tendency that the bonding reliability in the heating step is reduced.
Accordingly, the height of the projection 2a is set to be equal to the thickness of the flat plate portion of the lid body 0.
It is preferably in the range of 2 to 1.5 times.

Further, the width Y of the projection 2a is 1/10 of the width of the lid 2 in a direction perpendicular to the rolling direction (AB).
Preferably it is １ ／. When the width Y of the protrusion 2a is less than 1/10 of the width of the lid 2 in a direction perpendicular to the rolling direction (AB), the strength for suppressing deformation of the lid 2 in the rolling direction (AB) is increased. Insufficiently, the peeling force due to the warpage of the lid 2 acts between the insulating base 1 and the lid 2, and the bonding between the insulating base 1 and the lid 2 tends to be easily broken. On the other hand, if it exceeds 1/4, in a general thin semiconductor device, the space inside the container becomes narrow, and there is a risk that the bonding wire 7 comes into contact with the lid 2 to cause a short circuit. Therefore, the width Y of the protrusion 2a is determined in the rolling direction (AB).
It is preferable that the width is 1/10 to 1/4 of the width of the lid 2 in the direction perpendicular to the direction.

The projection 2a may have a shape other than a single line as shown in FIGS. 1 to 3, such as a plurality of lines or a frame. When the projections 2a are formed in a frame shape or a plurality of linear shapes, the sum of the widths Y of the projections 2a is 1/10 of the width of the lid 2 in a direction perpendicular to the rolling direction (AB). It is preferably set to １ ／.

The sectional shape of the projection 2a is triangular.
Various shapes such as a trapezoid are used. Further, as shown in the cross-sectional views of the main part of the lid 2 in FIGS. 4 and 5, the shape may be a trapezoid or an arc having a concave portion on the opposite side of the projection 2a. .

If such a lid 2 is made of, for example, an iron-nickel alloy, an ingot (lump) of an iron-nickel alloy is rolled by a rolling method into a plate-like shape, and a predetermined projection shape is obtained. In addition to press-molding with a press die manufactured corresponding to the above, it is formed into a predetermined size by a conventionally known punching method. Alternatively, it is also possible to form the protrusion 2a and form it into a predetermined outer size by chemical etching.

When the lid 2 is made of an iron alloy such as an iron-nickel alloy, an iron-cobalt alloy, or an iron-nickel-cobalt alloy, the surface of the lid 2 is made of nickel or gold to prevent corrosion. -It is preferable to coat with various metal plating such as solder.

The sealant 4 has a function of joining the insulating base 1 and the lid 2, and is made of glass, a resin adhesive, a brazing material, or the like.

The sealing agent 4 is preferably a resin adhesive having low elasticity from the viewpoint of stress relaxation. The sealing agent 4 is printed on the joint portion of the insulating base 1 or the lid 2 by using a conventionally known screen printing method or the like. After the application, the insulating substrate 1 and the lid 2 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 tends to increase, and the semiconductor element 3 tends to be 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.

The sealant 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 insulating substrate 1 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 lid 2 and the wiring conductor layer 5 are electrically connected to each other, and a shielding effect that prevents radiation of electromagnetic waves to the outside, A semiconductor element housing package can be obtained in which an immunity effect of preventing invasion of electromagnetic waves from the outside can be obtained favorably.

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. The ceramic green sheet serving as the insulating substrate 1 is printed and applied in advance by using a thick film method, and is fired at the same time as the ceramic green sheet, so that a predetermined pattern is formed on the upper surface of the insulating substrate 1.

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.

It is preferable that the conductive filler contains 0.5 to 200% by weight of a filler having an average particle size of 0.1 to 30 μm. And the electrical connection between the cover 2 and the frame-shaped conductor layer 6 tends to be difficult. There is a tendency that the 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 conductive filler is
A range from 0.5 to 200% by weight is preferred.

Thus, according to the semiconductor element housing package of the present invention, the semiconductor element 3 is bonded and fixed to the bottom surface of the mounting portion 1a of the insulating base 1 via an adhesive made of glass, resin, brazing material or the like. 3 are connected to the wiring conductor layer 5 by bonding wires 7, and then the insulating base 1 and the lid 2 are connected via the sealant 4 to form a container comprising the insulating base 1 and the lid 2. The semiconductor device 3 as a final product is completed by housing the semiconductor element 3 in an airtight manner.

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 package for housing a semiconductor element of the present invention, the cover made of a metal plate formed by a rolling method is provided substantially parallel to the rolling direction on the portion facing the opening of the concave portion of the insulating base. The length is 3 / the length of the lid in the rolling direction.
The heat generated when the semiconductor element is operated or the reflow after the secondary mounting is formed because the protrusion having a height of not less than 5 and not more than the length of the opening of the concave portion and having a height of 0.2 to 1.5 times the thickness of the flat plate portion is formed. Even if the strain stress remaining in the rolling process of the metal material is released by heating or the like, the projections of the lid suppress the deformation of the lid, and the lid does not deform significantly, as a result, the lid and the The bonding with the resin adhesive is not broken, and the hermetic reliability of the package is not reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view in the width direction of a protrusion showing an example of an embodiment of a semiconductor device housing package of the present invention.

FIG. 2 is a cross-sectional view in the length direction of a protrusion showing an example of an embodiment of a semiconductor device housing package of the present invention.

FIG. 3 is a plan view of a lid of the semiconductor device housing package shown in FIGS. 1 and 2;

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

FIG. 5 is a cross-sectional view of a main part of still another example of the lid in the semiconductor element storage package of the present invention.

FIG. 6 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 ... Lid 2a ... Projection part 3 ... Semiconductor element 4 ... .... Sealant 5 ... Wiring conductor layer X ... Length of protruding part Y ... Width of protruding part AB ... Rolling direction

Claims (4)

[Claims] 1. An insulating substrate having a concave portion on which a semiconductor element is mounted on an upper surface, and a substantially flat lid joined to the upper surface of the insulating substrate via a sealant so as to cover the concave portion. A package for storing a semiconductor element, wherein the lid is:
It is made of a metal plate by a rolling method, and has a length substantially parallel to the rolling direction, at least three-fifths of the length of the lid in the rolling direction, and a portion of the opening of the recess, which is opposed to the opening of the recess. Not more than the length, and the height is 0.2-1.
A package for accommodating a semiconductor element, wherein a five-fold protrusion is formed. 2. The package for accommodating a semiconductor element according to claim 1, wherein the width of the projection is 1/10 to 1/4 of the width of the lid in a direction perpendicular to the rolling direction. 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.