JPH0724291B2 - Integrated circuit container and manufacturing method thereof - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated circuit container for mounting a semiconductor chip and a manufacturing method thereof. More specifically, the present invention relates to an integrated circuit container made of a metal material, which is particularly suitable for a four-way lead-out type, and a manufacturing method thereof.

(Prior Art and Problems Thereof) There are two types of ceramics integrated circuit containers currently used, as shown in FIGS. 1 (a) and 1 (b). FIG. 1 (a) shows a rectangular planar shape. , FIG. 1 (b) shows the case of a square. The rectangular one is used for a lead two-way lead-out type package shown in a perspective view in FIG. 2 (a), and the lead 30 is taken out from the long side. The square one is used for a lead four-direction lead-out type package shown in FIG. 2B, and the lead 30 is taken out from four sides.
The 4-way lead type can take out a larger number of leads than the 2-way lead type.

By the way, as shown in FIG.
The direction extraction type ceramics container has a square recess 2 at the center of a square ceramic plate 1, and a semiconductor chip is mounted in the recess 2 via a glass or noble metal layer. The lead frame is mounted on the peripheral surface portion 3 surrounding the recessed portion via the attached glass and is connected to the leads of the semiconductor chip. Similar to the container 4, a container lid having a recessed portion and a peripheral surface portion surrounding the recessed portion is opposed to the recessed portion and the peripheral surface portion of the container and sealed as shown in FIG. 2 (b). Like the container 4, this container lid 4'is also a sintered body made of ceramics.

However, the ceramic container has the following drawbacks.

Since they are vulnerable to impact, there is a great risk that they may collide with each other to cause chipping during the transportation process. If sintering is incomplete, cracks may occur due to thermal shock.

Since the heat dissipation property is insufficient, malfunction is likely to occur when the degree of integration of the semiconductor chips is high and the heat generation is large.

Large shrinkage during firing and poor dimensional accuracy.

Warpage is likely to occur in the cooling process after firing, and there is a problem in flatness.

In order to overcome these drawbacks, the applicant has already made
In No. 60-146527, we proposed a container using metal.
When the container is made of metal, it is necessary to cover a portion that may come into contact with the lead frame with an electrically insulating layer. A metal oxide is suitable for the electrically insulating layer, and the applicant has already proposed in Japanese Patent Application No. 62-68642 an integrated circuit container provided with a metal oxide layer and a method for manufacturing the same.

According to this, a metal core material is coated with a metal forming an oxide on the peripheral surface, and a long plate-shaped material having a container width is cut into a predetermined length,
As shown in FIGS. 3 (a) and 3 (b), a recessed portion 7 is formed in the central portion, and then the coated metal layer 5b is subjected to an oxidation treatment to obtain a container
It is said that In this case, since the metal core material 5a is exposed at the cut roll and the cut ha, the lead is limited to the two-way lead-out type container shown in FIG. 1 (a). of course,
As shown in FIG. 4 (a), after the plate-shaped metal core material 6a is manufactured into a semi-finished product 8 having a square outer shape and a recessed portion 7 at the center, the cross-sectional view shown in FIG. As described above, it is also possible to form the coating metal layer 6b by plating or vapor deposition and then oxidize it to impart electrical insulation to the entire peripheral surface. However, in this method, the step of forming the coating metal layer on each semi-finished product 8 is inefficient and the productivity is low.

Thus, the object of the present invention is to eliminate the drawbacks of the prior art and to make an integrated circuit container made of a metal material that enables efficient production, particularly an integrated circuit container suitable for a lead 4-direction extraction type and a manufacturing method thereof. Is to provide.

(Means for Solving Problems) Here, the gist of the present invention is to provide a recess for mounting a semiconductor chip, and a peripheral surface part for mounting a lead frame surrounding the recess. An integrated circuit container having an outer edge of the peripheral surface portion formed of four sides for taking out leads, wherein one side having a through hole of the same plane size as the container recess in the central portion is smaller than the other side and at least the above A metal upper layer plate whose periphery and short side outer edge are covered with metal oxide, and a metal lower layer plate which has one side smaller than the other side and at least the short side outer edge is covered with metal oxide and has no through holes. Respectively satisfy the following formula (1), and the upper layer plate and the lower layer plate are arranged such that the short side of the upper layer plate is located outside the long side of the lower layer plate, and both are bonded with an adhesive layer. It is an integrated circuit container configured by being joined in a cross shape through.

b> l ′ and b ′> l (1) b: long side length of upper layer plate, l: short side length of upper layer plate b ′: long side length of lower layer plate, l ′: lower layer plate Further, from another aspect, the present invention includes a recess for mounting a semiconductor chip and a peripheral surface for surrounding the recess for mounting a lead frame. Is a method for manufacturing an integrated circuit container whose outer edge is composed of four sides for taking out leads, wherein a peripheral surface of a plate-shaped metal core material is covered with another metal so as to satisfy the following expression (2): A rectangular upper layer made of a long plate-shaped material having the same width as the integrated circuit container, having a length shorter than the width, and having a through hole of the same plane dimension as the container recess in the center. The process of processing the plate,
A step of processing a lower layer plate having a length shorter than a width dimension and having no through hole; a step of forming an oxide film on a coating metal layer of the upper layer plate, the lower layer plate; both of the upper layer plate and the lower layer plate; or A step of forming an adhesive layer on one surface and joining the adhesive layers in a cross shape so that the short side of the upper layer plate is located outside the long side of the lower layer plate with the adhesive layer sandwiched therebetween. And a step of manufacturing the integrated circuit container.

b> l ′ and b ′> l (2) b: long side length of upper layer plate, l: short side length of upper layer plate b ′: long side length of lower layer plate, l ′: lower layer plate The short side length of these upper and lower layers generally have substantially the same plane dimension.

(Operation) Next, an integrated circuit container of the present invention and a method for manufacturing the same will be described in detail with reference to the accompanying drawings.

5 (a), (b) and (c) show the structure of the integrated circuit container according to the present invention. The container 9 has a two-layer structure of an upper layer plate 10 and a lower layer plate 11 and is joined by an adhesive layer 12. A recess 7 for mounting a semiconductor chip is provided in the center of the container 9. An inner wall 7b of the recess 7 is an upper plate 10 and a bottom surface 7a thereof is a lower plate 11. That is, the upper layer plate 10 has a through hole equal to the plane dimension of the recess 7. Recess 7
Depth d is equal to the sum of the thickness ta of the upper plate 10 and the thickness tc of the adhesive layer 12.

Around the concave portion 7, a peripheral surface portion 14 for mounting a lead frame (not shown) is provided.

Both the upper layer plate 10 and the lower layer plate 11 have a rectangular shape, and each side has a slightly different length from the side orthogonal thereto. Each side length will be described later. As shown in FIG. 5 (a), the upper layer plate 10 and the lower layer plate 11 are overlapped and joined so as to have a slightly cross shape in a plan view.

The upper and lower surfaces of the upper layer plate 10 and the lower layer plate 11 and the short side edges are electrically insulating layers.
It is covered with 10b and 11b.

Hereinafter, manufacturing process steps of the upper layer plate 10 and the lower layer plate 11 will be described respectively.

FIG. 6 shows an example of an intermediate process for manufacturing the upper layer plate 10. A long plate-shaped material 16 having a width equal to the long side length b of the rectangular upper layer plate 10 is formed by coating the peripheral surface of the plate-shaped metal core material 16a with a metal layer 16b which forms an oxide in a later step. ing. As a method of manufacturing the long plate-shaped material 16, there are a method of rolling a rod-shaped clad material having a circular cross section and a method of coating a narrow-width plate-shaped metal core material with metal by plating or vapor deposition.

FIG. 6 shows a through hole 17 having the same plane dimension as the recess 7 (see FIG. 5) in which the semiconductor chip is mounted on the long plate-shaped material 16.
A state in which the upper side plate 10 is opened at a pitch of a short side length l is shown, and thereafter, the long plate-shaped material 16 is cut and separated along a broken line EE to obtain an upper layer plate semi-finished product 18. Of course, it is also possible to first cut into the length l and then process the through hole 17. Through hole 17
Is processed by punching. In addition, a long plate-shaped metal core material
There is also a method in which 16a is used as a material, through holes 17 are formed at a predetermined pitch, and then a coating metal layer 16b is formed by plating or vapor deposition, and then this long material is cut and separated along the broken line EE.

FIG. 7 shows a long plate-shaped material 19 of the lower layer plate 11. Width is lower plate
It is equal to the long side length b'of 11. The long plate-shaped material 19 is a metal layer 1 which forms an oxide on the peripheral surface of a plate-shaped metal core material 19a in a later step.
It is coated with 9b. The manufacturing method of this material 19 is the upper layer plate 10
It is similar to the long plate-shaped material 16. The material 19 is cut at the position of the broken line with a pitch equal to the short side length l'of the lower layer plate 11,
Lower plate half-finished product 20.

In addition, the plane dimensions of the upper layer half-finished product 18 and the lower layer half-finished product 20 are b
> L 'and b'> l.

The lengths l and l'are required and sufficient for lead extraction. When taking the same number of leads from the four sides, l = 1 '. b
And b'need not necessarily be the same.

The reason for b> l 'and b'> l is that the metal core material is exposed to the cut end in FIG. 6 and the cut roll in FIG. 7 and the bending of the lead frame mounted as described later. This is to ensure a wide gap between the legs so that they will not come into contact with each other. Δ
= (B-l ') / 2 and Δ' = (b'-l) / 2,
As a matter of course, the larger Δ and Δ ′ are, the more difficult it is to make contact.
According to the experience of the present inventor, if Δ ≧ 2tb and Δ ′ ≧ ta, there is no practical problem.

By the way, in the integrated circuit container 9 shown in FIG. 5, the linear expansion coefficient of the whole needs to be substantially equal to the linear expansion coefficient of the lead frame. This is because no thermal stress is generated between the container and the lead frame. When thermal stress is generated, there is a risk of cracks in the adhesive layer such as glass that seals the container and the lead frame. Therefore, for the core material 16a of the long plate-shaped material 16 and the core material 19a of the long plate-shaped material 19, for example, the same metal as the lead frame is used.

Aluminum is suitable for the coating metal layers 16b and 19b in terms of formation of an electric insulating film, adhesion with an adhesive (glass), and cost. According to the experience of the present inventor, a film thickness of 5 to 30 μm is sufficient.

Next, the coated metal layers of the upper layer plate semi-finished product 18 and the lower layer plate semi-finished product 20 are subjected to an oxidation treatment to impart electrical insulation properties, and the upper layer plate 10 and the lower layer plate 11
And An example of the oxidation treatment is anodization treatment that is performed electrochemically.

Next, the upper layer plate 10 and the lower layer plate 11 are laminated and adhered so as to have a slightly cross shape as shown in FIG. Airtightness is required for this adhesion. This is because the semiconductor chip is mounted on the recess 7 and the semiconductor chip after sealing the container lid is completely shielded from the outside air as described later. An example of the adhesive material in this case is the same as the glass for sealing the lead frame. First, glass powder is screen-printed on the bonding surface of the upper layer plate 10, and the lower layer plate 11 is laminated and fired to form the adhesive layer 12. Of course, the glass powder may be applied to the bonding surface of the lower layer plate 11 by screen printing,
As will be described later, when a semiconductor chip is mounted via a noble metal, it is necessary to apply it except for the bottom surface 7a of the recess. The thickness tc of the adhesive material layer 12 is 30 according to the experience of the present inventor.
-100 μm is enough.

The thickness ta of the upper layer plate 10 is determined by the depth d of the recess 7 and the thickness tc of the adhesive layer 12 as described above. As an example, d = 0.4 mm, tc = 0.1 mm, ta = 0.3 mm. Lower plate 1
The thickness tb of 1 is preferably thin from the viewpoint of heat dissipation of the semiconductor chip, but 0.1-0.3 mm is appropriate in consideration of the rigidity of the chip mounting portion.

The integrated circuit containers and the manufacturing method thereof according to the present invention have been described above. Mounting of the semiconductor chip and the lead frame on these containers and sealing with the container lid will be further described.

First, as for mounting a semiconductor chip, as shown in FIG.
As shown in (b), the adhesive layer 24 of the semiconductor chip 25 made of a noble metal is formed on the bottom surface of the recess 7 of the container 9. Glass may be used instead of the noble metal, and in that case, it may be the same as the adhesive layer 12 of the glass layer for bonding the upper layer plate 10 and the lower layer plate 11. Then, the adhesive layer 12 which is a glass layer may be formed on the entire bonding surface of the lower layer plate 11.

Next, glass powder is screen-printed on the metal oxide layer 10b on the peripheral surface portion 14 surrounding the recessed portion 7 of the container 9 and pre-baked to form the glass layer 23 for sealing as shown in FIG. The sealing glass is printed and fired by the above-mentioned upper layer plate.
10. The printing and firing of the glass for adhering the lower plate 11 can be performed at the same time. The semiconductor chip 25 has an adhesive layer 24.
Is melted by heating, and the lead frame 30 is mounted by melting the sealing glass layer 23 by heating. FIG. 8 (a) shows a state in which the lead frame 30 is mounted in the section ii in FIG. 5 and in the section (b) in FIG. Wiring the leads of the semiconductor chip 25 and the lead frame 30
Connected at 26.

According to the present invention, as shown in FIGS. 8 (a) and 8 (b), a step of Δ or Δ ′ is provided on each side between the upper layer plate 10 and the lower layer plate 11. This effectively prevents contact with the lead frame.

Next, the container lid will be supplementarily described.

9 (a) and 9 (b) show an example of a container lid 9'overlaid on the container according to the present invention shown in FIG. 8, for example. The plane dimension is l × l '(l: the length of the container upper layer plate 10, l': the length of the container lower layer plate 11). Similar to the container, it has a recessed portion 7'in the center, and an upper layer plate 10 'and a lower layer plate 11' are adhered to each other by an adhesive layer 12 'which is, for example, glass. Both the upper layer plate 10 'and the lower layer plate 11' are covered with metal oxide layers 10'b, 11'b on the upper and lower surfaces of the plate-shaped metal core materials 16'a, 19'a.
Since 27 does not require electrical insulation, a metal oxide layer is unnecessary. When the corrosion resistance of the metal core material is insufficient, the outer peripheral end face portion 27 may be coated with a rust preventive paint. If necessary, the anticorrosion treatment may be applied to the long side end faces 21 and 22 of the upper layer plate 10 and the lower layer plate 11 in which the metal core material is exposed in the container 9 shown in FIG.

A glass layer for sealing, for example, is formed on the peripheral surface portion 14 'surrounding the recessed portion 7'of the container lid 9', and the container 9 shown in FIG.
Are sealed so that their recesses face each other to form a semiconductor chip package.

(Effects of the Invention) The integrated circuit container according to the present invention is made of metal as a main material, so that it is resistant to impacts and can quickly dissipate heat, which contributes to high integration of semiconductor chips, which is strongly demanded today. Can handle. The metal plate that constitutes the container can be efficiently manufactured from a long material that covers the peripheral surface of the metal core material. In addition, since the rectangular plates obtained by subjecting the coated metal layer to the oxidation treatment are laminated in a cross shape, sufficient electrical insulation with the lead frames taken out in four directions can be obtained.

[Brief description of drawings]

FIGS. 1 (a) and 1 (b) are schematic explanatory views of a conventional ceramic integrated circuit container; FIGS. 2 (a) and 2 (b) are schematic perspective views, respectively; FIGS. 3 (a) and 3 (b). ) And FIGS. 4 (a) and (b),
FIG. 5 (a), (b), and (c) are schematic explanatory views of the metal integrated circuit container proposed earlier; FIG. 6 and FIG. 7 is a schematic perspective view of an upper layer plate and a lower layer plate, respectively; FIG. 8 is a schematic sectional view showing how a semiconductor chip and a lead frame are mounted on a metal integrated circuit container according to the present invention; (A), (b) is a schematic explanatory drawing of the container lid of the said metal integrated circuit container. 7: Recessed part, 9: Container 10: Upper layer plate, 11: Lower layer plate 12: Adhesive layer, 14: Peripheral surface part

Claims (2)

[Claims] 1. A recess for mounting a semiconductor chip,
A peripheral surface portion surrounding the recessed portion for mounting a lead frame, and an outer edge of the peripheral surface portion takes out the lead 4
In an integrated circuit container composed of two sides, one side in which a through hole having the same plane size as the container recess is opened in the center is smaller than the other side, and at least the peripheral surface portion and the outer edge portion on the short side are metal oxide. The metal upper layer plate covered with and the metal lower layer plate having one side smaller than the other side and at least the outer edge of the short side covered with metal oxide and having no through hole satisfy the following formula (1). An integrated structure in which the upper layer plate and the lower layer plate are arranged such that the short side of the upper layer plate is located outside the long side of the lower layer plate, and the two are joined in a cross shape via an adhesive layer. Circuit container. b> l ′ and b ′> l (1) b: long side length of upper layer plate, l: short side length of upper layer plate b ′: long side length of lower layer plate, l ′: lower layer plate Short side length of 2. A recess for mounting a semiconductor chip,
A method for manufacturing an integrated circuit container, comprising: a peripheral surface portion for mounting a lead frame, the peripheral surface portion surrounding the recessed portion; So that the peripheral surface of a plate-shaped metal core material is covered with another metal, a long plate-shaped material having the same width dimension as the integrated circuit container is used as a raw material, and the length is shorter than the width dimension. Then, a step of processing a rectangular upper layer plate having a through hole of the same plane dimension as the container recessed portion in the center part, and a step of processing a lower layer plate having a length shorter than the width dimension and having no through hole, A step of forming an oxide film on the coating metal layer of the upper plate and the lower plate,
A step of forming an adhesive layer on one or both surfaces of the upper layer plate and the lower layer plate, and sandwiching the adhesive layer so that the short side of the upper layer plate is located outside the long side of the lower layer plate. And a step of joining both of them in a cross shape. b> l ′ and b ′> l (2) b: long side length of upper layer plate, l: short side length of upper layer plate b ′: long side length of lower layer plate, l ′: lower layer plate Short side length of