JPH0794631A - Ceramic circuit board - Google Patents

Abstract

PURPOSE:To provide a highly reliable ceramic circuit board in which high density and high integration are realized by forming a fine thin film pattern on a ceramic board. CONSTITUTION:In ceramic circuit board 16 wherein a Cu conductor film layer 12 is deposited on a ceramic board 11, a Cu oxide layer 13 or a Cu nitride layer is interposed between the ceramic board 11 and the Cu conductor film layer 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic circuit board such as an AlN circuit board used as a circuit board for mounting semiconductor elements and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, semiconductor devices have been highly integrated and highly densified.
With the increase in speed, the power consumption of semiconductor devices has increased.
Therefore, increasing the heat generation of the semiconductor element has become a problem.

Conventionally, semiconductor elements such as LSIs have been packaged with plastic, metal, ceramics, etc., but the problem of deterioration of the semiconductor element due to heat generation of the semiconductor element cannot be sufficiently dealt with and is becoming a limit. .

As one of the methods for solving the problem of deterioration of semiconductor elements, a method of using a ceramic having high thermal conductivity for a substrate of a semiconductor package has been developed. Above all, attention is paid to the use of AlN, which is a ceramic having a high thermal conductivity, as a circuit board for mounting a semiconductor element. AlN
Circuit boards are currently in practical use as high-power power module boards and packages for supercomputers.

When using AlN as a circuit board for mounting semiconductor elements, it is necessary to metallize the AlN board. As a method of metallizing a ceramic AlN substrate, there are generally a thick film printing method and a thin film forming method. However, since it is difficult to form wiring having a thickness of 100 μm or less in the thick film printing method, high density wiring cannot be performed. 1 if high-density wiring is required
A thin film deposition method that enables wiring of 00 μm or less is suitable.

Conventionally, Al metallized by a thin film forming method
In the case of the N substrate, a method has been used in which different kinds of metal thin films are formed in a multilayer structure on the substrate and then a circuit pattern (wiring pattern) is formed by using photolithography.

As an example, Ti, C is formed on a polished AlN substrate by a thin film forming method such as a sputtering method or an evaporation method.
A thin film of r, Zr or the like is formed as a bonding layer between the ceramic substrate and the metal thin film, and a film of Ni, Pt or the like as a diffusion barrier layer is laminated on this thin film as an intermediate layer. Au, Cu or the like is formed as a wiring conductor layer on the stacked films to form a multilayer film structure.

A wiring pattern of 100 μm or less is formed on a multilayer film of an AlN substrate by a series of photolithography processes of resist coating, exposure, development, and etching to obtain a package, a circuit board, or the like.

FIG. 8 shows an example of a conventional AlN circuit board. This AlN circuit board 1 has a Ti layer 3 as a bonding layer on the AlN substrate 2 and a Ni layer 4 as a diffusion barrier layer on the Ti layer 3. Is provided with an Au layer 5 as a conductor wiring layer on the Ni layer 4 to form a multilayer metal thin film structure.

This AlN circuit board 1 of the multilayer metal thin film structure
In the above, the activity of Ti, Cr, Zr, etc. used as the bonding layer is high, and the AlN substrate 2 which is a ceramic substrate is used.
Has good adhesion to, but since the electrical resistivity after heat treatment is large, Au plating must be performed on the thin film wiring,
There is a property not suitable for wiring materials.

Further, Au, C used for the conductor wiring layer 5
Although u or the like has a low resistivity and is suitable for a conductor wiring, it has a low bonding property to an AlN substrate due to its low activity.

Therefore, in the AlN circuit board 1, the bonding layer 3 and the conductor wiring layer 5 are overlapped, and an N diffusion layer 4 is formed between them.
A multilayer metal thin film structure is adopted with i, Pt and the like with an intermediate layer interposed. In the diffusion barrier layer 4, the metals of the bonding layer 3 and the conductor wiring layer 5 diffuse into each other, and the bonding layer 3 and the conductor wiring layer 5
It has the role of preventing the decrease in the adhesiveness and the increase of the electric resistance.

Conventionally, the AlN circuit board 1 having such a multilayer metal thin film structure has been used as a semiconductor mounting circuit board.

Further, the metallization of the Cu conductor wiring layer 5 on the AlN substrate 2 is made by a method other than the film formation method using a multilayer metal thin film. For example, a Cu thick plate is placed on a surface-oxidized AlN substrate, a liquid phase of Cu oxide is formed at a temperature of 1000 ° C. or higher, and the Cu thick plate and the AlN substrate are bonded to each other.
There is C method (direct bonding kappa method). This D
The BC method has an advantage that a Cu conductor can be used alone, but since the Cu plate thickness is as large as 300 μm, it cannot cope with miniaturization of wiring and Cu wiring cannot be formed at high density.

[0015]

The conventional AlN circuit board 1 has a multi-layer metal thin film structure, and different metal thin films are formed on the AlN substrate 2 as the bonding layer 3, the diffusion barrier layer 4, and the conductor wiring layer 5. I had to do it. Therefore, the number of thin film forming processes such as sputtering and vapor deposition increases,
Moreover, since the etching process for forming the wiring pattern is long, the manufacturing process is long and the cost is high.

Further, in the AlN circuit board having a multi-layer metal thin film structure, since different kinds of metal thin films have to be multi-layered, a high temperature treatment in a post process causes metal interdiffusion.
Adhesion is lowered, resistance is increased, and the like, which is a cause of lowering reliability as a circuit board.

Furthermore, since the conventional Cu wiring board is manufactured by thick film printing or the DBC method, it is difficult to form Cu wiring of 100 μm or less. Also, AlN
When the Cu film is directly formed on the substrate, Cu has a low activity, and thus there is a possibility that defective adhesion of Cu to the AlN substrate may occur.

The present invention has been made in consideration of the above circumstances, and a fine ceramic film is formed on a ceramic substrate to achieve high density and high integration, and a highly reliable ceramic circuit substrate and the same. It is intended to provide a manufacturing method.

Another object of the present invention is to use a thin film method for forming a fine thin film pattern, to enable metallization that does not require a bonding layer of a metal different from the conductor layer, and to manufacture a ceramic in a short manufacturing process. A circuit board and its manufacturing method are provided.

[0020]

In order to solve the above-mentioned problems, a ceramic circuit board according to the present invention has a Cu film formed on a ceramic substrate by a thin film forming method.
In a ceramic circuit board having a conductor film layer formed thereon, a Cu oxide layer or a Cu nitride layer is interposed between the ceramic substrate and the Cu conductor film layer.

In order to solve the above-mentioned problems, in the ceramic circuit board according to the present invention, in addition to the contents described in claim 1, the ratio of Cu to oxygen in the Cu oxide layer as described in claim 2 or The ratio of Cu to nitrogen in the Cu nitride layer is changed continuously or stepwise in the layer.

In order to solve the above-mentioned problems, in the method of manufacturing a ceramic circuit board, a Cu target is used on the ceramic board and an inert gas and O ₂ or N ₂ are used.
_A Cu oxide layer or a Cu nitride layer is formed by a thin film forming method in ₂ gas, a Cu conductor film layer is formed on this Cu oxide layer or a Cu nitride layer, and wiring is performed on this Cu conductor film layer. A manufacturing method of forming a pattern can be used.

[0023]

The ceramic circuit board according to the present invention is characterized by claim 1.
When a ceramic substrate such as an AlN substrate and a Cu conductive film layer are bonded together by interposing a Cu oxide layer or a Cu nitride layer between the ceramic substrate and the Cu conductive film layer, the intermediate Cu oxide layer or Cu
In the presence of the nitride layer, the Cu conductor layer is bonded to the ceramic substrate without using an active bonding metal such as Ti, Cr, Zr, etc., and good adhesion is obtained. Can be metallized without intervening. The Cu conductor layer can form a fine thin film pattern of 100 μm or less on a ceramic substrate by using a thin film method.
It is possible to provide a highly reliable ceramic circuit board which can achieve high density and high integration.

Further, as described in claim 2, in the Cu oxide layer or the Cu nitride layer used for the ceramic circuit board, the ratio of Cu and oxygen or the ratio of Cu and nitrogen is changed continuously or stepwise. By letting
The adhesion strength between the ceramic substrate such as the AlN substrate and the Cu conductor film layer can be further improved.

Further, in the method for manufacturing a ceramic circuit board, a Cu conductor film layer having excellent adhesion can be formed into a thin film by exposure to a high temperature by a conventional thin film forming method such as a sputtering method or an evaporation method, and the thickness is 100 μm or less. Since the wiring pattern can be formed, high density and high integration can be achieved.

[0026]

EXAMPLE An example of the ceramic circuit board according to the present invention will be described below.

FIG. 1 shows a quad flat package (hereinafter, referred to as QFP) 10 as a semiconductor package equipped with the ceramic circuit board of the present invention.

This QFP 10 is a ceramic substrate A
A Cu conductor film layer 12 is formed on an In substrate 11 via a CuxO film layer 13, which is a Cu oxide layer, as shown in FIG.
A wiring pattern is applied to the Cu conductor film layer 12. The Cu conductor film layer 12 is a ceramic circuit board made of AlN, which is formed by sequentially laminating a thin film layer 14 of Ni, Pt, or the like forming a diffusion barrier layer, and a surface layer 15 of Au with low activity, as needed.
The circuit board 16 is configured. Reference numeral 17 is a thin film layer of Al ₂ O ₃ formed by oxidizing the AlN substrate 11.

The AlN circuit board 16 is covered and protected by an AlN cap 18, which is a ceramic cap. A
In the 1N circuit board 16, external leads 20 made of Cu or the like are connected in four directions via a brazing filler metal 19 made of Ag-Cu or the like.
P10 is obtained.

AlN circuit board 1 of the manufactured QFP 10
FIG. 3 shows an analysis diagram showing the elemental composition components in the vicinity of the interface between the AlN substrate 11 and the thin film formation which constitutes No. 6.

Next, the manufacturing procedure of the QFP 10 will be described.

The ceramic circuit board 16 which constitutes this QFP 10 is one in which a single layer wiring is formed of a Cu thin film on the AlN substrate 11 using Y ₂ O ₃ as a sintering aid.

When manufacturing the QFP 10, first, Al is used.
An N substrate 11 is prepared, and polishing is performed to eliminate the warp of the AlN substrate 11 and facilitate patterning of thin film wiring. The AlN substrate 11 is polished by Al ₂ O ₃ or S
Powder such as iC is used as an abrasive.

After polishing the AlN substrate 11, the AlN substrate 11 is ultrasonically cleaned using a cleaning agent such as a neutral detergent or pure water in order to perform sputtering on the AlN substrate 11.
RF sputtering is used for sputtering the AlN substrate 11, Cu is used as a target, and Ar, which is an inert gas, is used.
And O ₂ are used as the used gas.

The thin film is formed on the AlN substrate 11 by first sputtering for 5 minutes at a mixing ratio of O ₂ and Ar in a volume ratio of 90:10, and then forming a mixing ratio of O ₂ and Ar. Sputter film formation at 50:50 for 5 minutes, and finally 100% A
The AlN substrate 11 is formed by sputtering for 10 minutes.
A film such as the Cu oxide layer 13 is formed on top. The RF sputtering power is 1 kW.

The thickness of the thin film layer formed on the AlN substrate 11 by this RF sputtering is about 100 nm for the lower Cu oxide layer 13 and the thickness of the Cu film layer constituting the upper Cu conductor film layer 12. Is about 1 μm, and in the layer, the ratio of Cu and O ₂ changes continuously or stepwise from the lower layer to the upper layer.

In order to form wiring on the Cu film layer, a wiring pattern having a thickness of about 10 μm is formed using a positive resist, Cu is electroplated, and a Cu conductor film layer is formed on the Cu oxide layer 13. 12 was formed. Thickness of Cu plating is about 1
It is 0 μm. The film layers 12 and 13 formed by thin film formation on the AlN substrate 11 have a thickness of about 10 μm.

After that, a positive type resist is applied to the AlN substrate 11
From the Cu conductor film layer 12 other than the wiring pattern and Cu
The oxide layer 13 is etched with ferric chloride to remove AlN.
The circuit board 16 was constructed. The wiring width of the wiring pattern is about 4
It is 0 μm, the distance between lines is about 60 μm, and Cu wiring of 100 μm or less can be easily formed.

External Cu lead 2 to AlN circuit board 16
For the connection of 0, the Ag-Cu sheet 2 mm width is connected to the external lead 2
0 and the AlN circuit board 16 are sandwiched between them and put into a C jig and heat-treated at 830 ° C., for example. By this heat treatment, A
The g-Cu sheet melts and connects the Cu external lead 20 and the wiring. At that time, since it is not necessary to heat to 1000 ° C. or higher, the Cu oxide is not liquefied. When a nitride layer is used instead of the copper oxide layer 13, an external lead made of Sn-Pb sheet may be used instead of Ag-Cu sheet. At this time, since the heat treatment at a relatively low temperature of about 230 ° C. may be performed, reduction of the nitride can be prevented.

In the first embodiment, the ultrasonically cleaned AlN is used.
An example in which the substrate 11 is sputtered using RF sputtering is shown, but as a modified example, the cleaned AlN substrate 1
1 may be vapor-deposited by an ordinary vapor deposition method to form a thin film.

In this case, the cleaned AlN substrate 11
Vapor deposition. An E gun was used for sputtering on the AlN substrate 11, Cu was used as a target, and Ar and O ₂ which are inert gases were used as gases to be used.

A Cu oxide layer (Cux) on the AlN substrate 11
The O) layer 13 is formed at a mixing ratio of O ₂ and Ar of 8 at first.
The film formation was performed at 0:20 for 30 seconds, followed by film formation at a mixing ratio of O ₂ and Ar of 50:50 for 30 seconds, and finally 100% Ar for 1 minute. The E gun input is 500W.

Also in this case, the thickness of the Cu oxide (CuxO) layer 13 formed as the lower layer on the AlN substrate 11 is about 1 or less.
00 nm, the thickness of the Cu film layer constituting the upper Cu conductor film layer 12 is about 1 μm, and in the Cu oxide layer 13, the ratio of Cu and O ₂ is continuous or stepwise from the lower layer to the upper layer. Change.

The electroplating of Cu for forming the wiring on the Cu film layer, the etching treatment with ferric chloride for forming the wiring pattern, and the connection of the external leads are not different from those in the first embodiment, and the description thereof will be omitted. . Also in this case, the wiring width of the wiring pattern is about 40 μm, and the space between the lines is about 60 μm.
The N circuit board 16 was obtained.

4 and 5 show a second embodiment of the present invention, showing a semiconductor package 10A having a ceramic circuit board.

In this semiconductor package 10A, a Cu conductor film layer 21 is formed on the AlN substrate 11 which is a ceramic substrate by Cu.
A thin film is formed through the Cu ₂ O layer 22 which is an oxide layer, and a wiring pattern is formed on the Cu conductor film layer 21 to form the AlN circuit board 23 as a ceramic circuit board. A chip capacitor 24 is mounted on a required portion on the Cu conductor film layer 21 via a bump 26 made of Sn or Sn-Pb.

While the AlN circuit board 23 is covered with the cap 25, the external leads 20 made of Cu or the like are connected to the wiring of the AlN circuit board 23 via the brazing material 19 to form the semiconductor package 10A. The brazing material 19 is, for example, A
It is formed of a g-Cu sheet.

Next, the procedure for manufacturing the ceramic circuit board 23 constituting the semiconductor package 10A will be described.

The ceramic circuit board 23 constituting this semiconductor package 10A is one in which a single layer wiring is formed by a Cu thin film on the AlN substrate 11 using Y ₂ O ₃ as a sintering aid.

To manufacture the ceramic circuit board 23, the AlN board 11 which is a ceramic board is prepared and the AlN board 11 is prepared.
Polishing is performed using powder such as Al ₂ O ₃ or SiC in order to facilitate patterning of the thin film wiring while eliminating warpage of the substrate 11.

After polishing the AlN substrate 11, the AlN substrate 11 is used for sputtering the AlN substrate 11.
Ultrasonically clean with a neutral detergent or pure water. AlN
For sputtering on the substrate 11, Cu is used as a target by using RF sputtering, and O ₂ and an inert gas such as Ar are used as a used gas.

For the thin film formation on the AlN substrate 11, first, O
The mixing ratio of ₂ and Ar is deposited by sputtering for five minutes at 90:10 volume ratio, the mixing ratio of the subsequently O ₂ and Ar 5
Thin film is formed at 0:50 for 5 minutes, and finally 100% Ar for 1
Sputter film formation is performed for 0 minutes. The power of RF sputter is 1 kW.

By sputtering on the AlN substrate 11, the Cu oxide layer 22 is formed as the lower layer and the Cu film layer constituting the Cu conductor film layer 21 is formed as the upper layer. Lower Cu oxide layer 2
2 has a thickness of about 100 nm, and the upper Cu film layer has a thickness of about 1 μm.

In order to form wiring on the Cu film layer, a wiring pattern having a thickness of about 10 μm was formed using a positive resist, and Cu was electroplated. The thickness of Cu plating is about 10 μm.

After Cu plating, the positive resist is peeled off,
Cu conductor film layer 21 and Cu oxide layer 2 other than the wiring pattern
2 is etched with ferric chloride and AlN circuit board 2
Configured 3. Also in this case, the thickness of the thin film formed on the AlN substrate 11 can be set to about 10 μm.

The line width of the wiring pattern of the obtained AlN circuit board 23 is about 40 μm and the space between the lines is about 60 μm.
It is possible to easily obtain Cu wiring having a thickness of 00 μm or less.

As a modification of the second embodiment, after the AlN substrate 11 is ultrasonically cleaned, the AlN substrate 11 is immersed in pure water to form an oxide film (Al ₂ O ₃ ) on the surface of the AlN substrate 11. And heat to about 100 ° C. This makes A
The AlN substrate 11 may be sputtered by RF sputtering with the oxide film formed on the surface of the 1N substrate 11. The manufacturing process after the sputtering of the AlN substrate 11 does not differ from that shown in the second embodiment, and therefore its explanation is omitted.

Also according to this modification, an AlN circuit board having a wiring pattern having a wiring width of about 40 μm and a line spacing of about 60 μm was obtained.

FIG. 6 shows a third embodiment of the present invention.
A pin grid array package (Pin Grid Array Packa) as a semiconductor package equipped with a ceramic circuit board.
ge: Hereinafter referred to as PGA. ) 10B is shown.

This PGA 10B has a single-layer wiring formed of a Cu thin film on an AlN co-firing substrate 30 which is a ceramic substrate using Y ₂ O ₃ as a sintering aid.

The PGA 10B shown in FIG. 5 is a type of LSI package in which the lead pins 31 are taken out from the lower surface of the package, and is an AlN co-firing substrate 3 which is a ceramic substrate.
The Cu conductor film layer 21 having a wiring pattern formed thereon is laminated on the surface of the AlO circuit board 0 to form the AlN circuit board 33 as a ceramic circuit board.

The AlN circuit board 33 is made of Ag—Cu brazing material 3.
The PGA 10B is formed by being integrally covered with a cap via the PGA 10B, and the lead pin 31 is taken out from the lower surface of the package of the PGA 10B.

Next, the procedure for manufacturing the ceramic circuit board 33 constituting the PGA 10B will be described.

This PGA 10B uses Y ₂ O ₃ as a sintering aid and has a single-layer wiring formed of a Cu thin film on an AlN co-firing substrate 30 which is a ceramic substrate.

At the time of manufacturing the PGA 10B, first, the AlN co-fired substrate 30 is removed from warpage, while polishing is performed to facilitate patterning of thin film wiring. Al
To polish the N co-firing substrate 30, powder of Al ₂ O ₃ or SiC is used as a polishing agent.

After polishing the AlN co-fired substrate 30, A
In order to perform sputtering on the 1N co-fired substrate 30,
The substrate is ultrasonically cleaned with a neutral detergent or pure water. RF sputtering is used for sputtering the AlN co-fired substrate 30, and a thin film is formed by using Cu as a target, O _{2 as} a used gas, and Ar as an inert gas.

The thin film formation on the AlN co-fired substrate 30 is as follows.
First, when the mixture ratio of O ₂ and Ar is 90:10 by volume, 5
Sputtering for a minute to form a film, followed by sputter film formation for 5 minutes at a mixture ratio of O ₂ and Ar of 50:50, and finally 10
Sputtering is performed for 10 minutes with 0% Ar to form a thin film on the AlN co-fired substrate 30. The RF sputtering power is 1 kW.

By this RF sputtering, a thin Cu film layer composed of the lower Cu oxide layer 22 and the upper Cu conductor film layer 21 is formed on the AlN co-fired substrate 30. The thickness of the thin film formed is about 100 nm in the lower Cu oxide layer 22.
The thickness of the upper Cu film layer is about 1 μm. In order to form a wiring on the Cu film layer, a wiring pattern is formed to a thickness of about 10 μm using a positive type resist and Cu electroplating is performed. The thickness of the Cu plating is, for example, about 10 μm.

After Cu plating, the positive type resist was peeled off from the AlN co-fired substrate 30, and the Cu conductor film layer 21 and the Cu oxide layer 22 other than the wiring pattern were etched with ferric chloride as an etching solution to form AlN. Circuit board 33
As a ceramic circuit board. It was possible to obtain the AlN circuit board 33 in which the wiring width of the wiring pattern was about 40 μm and the distance between the lines was about 60 μm.

The lead pin 31 to the AlN circuit board 33 is made of Kovar, and has a head shape with a plate at the rod end. The head 36 of the lead pin 31 has, for example, Ag-C.
The brazing material 34 of u is attached to the head 3 of the lead pin 31.
5 and the AlN co-fired substrate 30 are put together in a jig made of C and heat-treated at 830 ° C., for example. The brazing material 34 is melted by heat treatment to join the thin film wiring and the lead pin, and the PGA 10B is manufactured.

In each of the embodiments of the ceramic circuit board according to the present invention, Cu oxide (Cux) is formed between the Cu conductor film layers formed in a thin film on the AlN substrate which is a ceramic substrate.
An example in which the (O) layer is integrally interposed and the adhesion of the Cu conductor film layer is enhanced by this Cu oxide layer is shown, but instead of this Cu oxide layer, a Cu nitride layer is integrally interposed. It may be used as a bonding layer to improve the adhesion of the Cu conductor film layer.

In any case, by interposing a Cu oxide (CuxO) layer or a Cu nitride layer integrally between the AlN substrate and the Cu conductor film layer, Zr, Ti, etc., which are active as a bonding layer, can be formed. There is no need to use dissimilar metals. N ₂ gas and an inert gas such as Ar are used as a used gas for forming the Cu nitride layer.

[0073]

As described above, the ceramic circuit board according to the present invention is configured as described in claim 1, and the Cu oxide layer or the Cu nitride layer is provided between the ceramic substrate and the Cu conductor film layer. When a ceramic substrate such as an AlN substrate and a Cu conductor film layer are joined by interposing, a Cu oxide layer or a Cu nitride layer is present in the middle,
Even without using an active bonding metal such as i, Cr or Zr, C
By bonding the u conductor layer to the ceramic substrate, good adhesion can be obtained, and metallization can be performed without interposing a different active metal as a bonding layer. Since the Cu conductor layer can be formed on the ceramic substrate with a thin film having a thickness of 100 μm or less, it is possible to form a fine thin film pattern, achieve high density and high integration, and provide a highly reliable ceramic circuit substrate. .

Further, as described in claim 2, in the Cu oxide layer or the Cu nitride layer used for the ceramic circuit board, the ratio of Cu to oxygen or the ratio of Cu to nitrogen is changed continuously or stepwise. By letting
The adhesion strength between the ceramic substrate such as the AlN substrate and the Cu conductor film layer can be further improved.

Further, in the case where the method for manufacturing a ceramic circuit board according to the present invention is set forth in claim 3, without exposing to a high temperature by a thin film forming method such as a usual sputtering method or vapor deposition method, Since the Cu conductor film layer having excellent adhesiveness can be formed into a thin film and a wiring pattern of 100 μm or less can be formed, high density and high integration can be achieved.

[Brief description of drawings]

FIG. 1 shows a first embodiment of the present invention and is a diagram showing an example of a QFP provided with a ceramic circuit board.

FIG. 2 is a diagram showing a cross-sectional structure of a portion A of a ceramic circuit board that constitutes the QFP of FIG.

FIG. 3 is a composition analysis diagram in the vicinity of an interface between a ceramic substrate and a thin film forming portion of a ceramic circuit substrate.

FIG. 4 shows a second embodiment of the present invention and is a diagram showing an example of a semiconductor package including a ceramic circuit board.

5 is a cross-sectional view of a B portion of the ceramic circuit board that forms the semiconductor package of FIG.

FIG. 6 shows a third embodiment of the present invention and is a diagram showing an example of a PGA provided with a ceramic circuit board.

7 is a cross-sectional view of a C portion of the ceramic circuit board forming the PGA of FIG.

FIG. 8 is a diagram showing a conventional ceramic circuit board.

[Explanation of symbols]

10 QFP (Quad Flat Package) 10A Semiconductor Package 10B PGA (Pin Grid Array Package) 11 AlN Substrate (Ceramic Substrate) 12, 21 Cu Conductive Film Layer 13, 22 Cu Oxide Layer 16, 23, 33 AlN Circuit Substrate (Ceramic Circuit) Substrate) 18 AlN cap 20 Lead 25 Cap 31 Lead pin 35 Head

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kyoaki Yasumoto 1 Komukai Toshiba Town, Saiwai-ku, Kawasaki City, Kanagawa Prefecture Toshiba Research and Development Center (72) Inventor Nobuo Iwase Komukai, Kawasaki City, Kanagawa Prefecture Toshiba Town No. 1 Inside Toshiba Research and Development Center

Claims (2)

[Claims] 1. A Cu film formed on a ceramic substrate by a thin film forming method.
A ceramic circuit board having a conductor film layer formed thereon, wherein a Cu oxide layer or a Cu nitride layer is interposed between the ceramic substrate and the Cu conductor film layer. 2. The ceramic circuit board according to claim 1, wherein the ratio of Cu to oxygen in the Cu oxide layer or the ratio of Cu to nitrogen in the Cu nitride layer is changed continuously or stepwise within the layer.