JP2574902B2 - Semiconductor device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an element mounting substrate in a semiconductor device having a semiconductor element mounted thereon and a method of manufacturing the same.

[Conventional technology]

Conventional semiconductor devices have Si elements with different coefficients of thermal expansion.
No GaAs element was mounted on the same substrate, only the Si element or only the GaAs element was mounted.

Further, as described in JP-A-63-111659, a GaAs device is formed on a Si device. Further, the conventional element mounting substrate has a uniform thermal expansion coefficient between the thermal expansion coefficient of the element and the thermal expansion coefficient of the module substrate.

[Problems to be solved by the invention]

In the above prior art, since the Si element and the GaAs element are mounted on different substrates, the wiring length between the semiconductor elements becomes longer,
There is a problem that the signal propagation delay is large.

When a GaAs element is formed on a Si element,
Since the thermal expansion coefficients of GaAs are different, there has been a problem that the connection reliability between the Si portion and the GaAs portion is low, and the GaAs is easily peeled off and broken due to a temperature cycle.

An object of the present invention is to reduce signal propagation delay by mounting a plurality of types of elements having different thermal expansion coefficients on a substrate with a short wiring length between the elements and high reliability. In other words, it is to provide a plurality of types of elements having different thermal expansion coefficients close to each other on the same substrate with high reliability and to provide an element mounting substrate.

Another object of the present invention is to reliably mount an element having a thermal expansion coefficient different from that of the substrate on the substrate.

[Means for solving the problem]

In order to achieve the above object, a plurality of green sheets comprising a plurality of components having different coefficients of thermal expansion, each having a slightly different mixing ratio of the components, are laminated, thermocompressed, debindered, sintered, and then sintered in a thickness direction. A substrate having a slope of a coefficient of thermal expansion is manufactured. On a module substrate having a thermal expansion coefficient equal to or higher than the thermal expansion coefficient of the element having the lowest thermal expansion coefficient and equal to or lower than the thermal expansion coefficient of the element having the highest thermal expansion coefficient among a plurality of types of semiconductor elements having different thermal expansion coefficients, Prepared by the method of
As going from the module substrate side to the element side, a substrate for mounting an element is mounted in which the coefficient of thermal expansion is sequentially changed from the value of the coefficient of thermal expansion of the module substrate to the value of the coefficient of thermal expansion of each element. Each device is mounted thereon.

In addition, on a module substrate having a thermal expansion coefficient equal to the thermal expansion coefficient of one of a plurality of types of semiconductor elements, only the one type of semiconductor element is directly mounted or the semiconductor element and the module substrate are mounted. The other semiconductor elements are mounted on the module substrate via the element mounting substrate having a coefficient of thermal expansion equal to the coefficient of thermal expansion of the module. The components may be mounted via element mounting substrates that are sequentially changed from the value of the thermal expansion coefficient of the substrate to the value of the thermal expansion coefficient of each element.

Further, in the above-described means, a part or all of the module substrate and the element mounting substrate may be collectively laminated at the time of manufacturing to form one substrate, and the element may be mounted thereon.

In addition, on a module substrate having a thermal expansion coefficient equal to or higher than the thermal expansion coefficient of the element having the lowest thermal expansion coefficient and equal to or lower than the thermal expansion coefficient of the element having the highest thermal expansion coefficient among a plurality of types of semiconductor elements, An element mounting substrate having a thermal expansion coefficient between the value of the expansion coefficient and the value of the thermal expansion coefficient of each element may be mounted, and each element may be mounted thereon.

In addition, on a module substrate having a thermal expansion coefficient equal to the thermal expansion coefficient of one of a plurality of types of semiconductor elements, only the one type of semiconductor element is directly mounted or the semiconductor element and the module substrate are mounted. Mounted via an element mounting substrate having a thermal expansion coefficient equal to the coefficient of thermal expansion of the other semiconductor elements, on the module substrate,
An element mounting substrate having a coefficient of thermal expansion between the value of the coefficient of thermal expansion of the module substrate and the value of the coefficient of thermal expansion of each element may be mounted, and each element may be mounted thereon.

Further, on a device mounting substrate having a uniform thermal expansion coefficient as described above, a device mounting device having a value of thermal expansion coefficient between the value of the thermal expansion coefficient of the device mounting substrate and the value of the thermal expansion coefficient of each device. One or more substrates may be further mounted, and each element may be mounted thereon.

Also, when providing a gradient of thermal expansion in the thickness direction of the element mounting substrate, the gradient is not linear, and the thermal stress distribution in the thickness direction of the element mounting substrate when the element is actually mounted and operated. It is better to provide them so that

Also, in order to form a single substrate by laminating a part or all of the module mounting substrate having a gradient of thermal expansion coefficient with the module substrate at the time of fabrication, a plurality of green sheets of the same composition are laminated and A plurality of green sheets in which the value of the thermal expansion coefficient is sequentially changed may be formed by laminating, thermocompression bonding, binder removal, and sintering.

When a multilayer wiring board is manufactured by using the above-described means, a hole may be formed in a predetermined position of the green sheet before laminating the green sheet, and after the conductor is printed, the multilayer wiring board may be manufactured by using the above-described means.

To mount an element having a coefficient of thermal expansion different from the coefficient of thermal expansion of the substrate on the substrate, the value of the coefficient of thermal expansion prepared by the above-described method is set on the substrate in the thickness direction. It is sufficient to mount an element mounting substrate which is sequentially changed from the value of the coefficient of thermal expansion to the value of the coefficient of thermal expansion of the element, and mount the element thereon.

[Action]

In the semiconductor device manufactured by the above method, the value of the coefficient of thermal expansion between the semiconductor element and the module substrate is changed from the value of the coefficient of thermal expansion of the Through the device mounting substrate that is sequentially changed to the value of the thermal expansion coefficient of the semiconductor device, there is a large difference in the thermal expansion coefficient between the connection portion between the semiconductor device and the device mounting substrate and the connection portion between the device mounting substrate and the module substrate. Therefore, no breakage due to thermal stress occurs in each connection portion. Therefore, by using this method, a plurality of types of semiconductor elements having different thermal expansion coefficients can be mounted on the same module substrate in close proximity and with high reliability.

〔Example〕

Embodiment 1 One embodiment of the semiconductor device of the present invention is shown in FIG. 1 as a cross-sectional view. In FIG. 1, reference numerals 1 and 2 denote a Si semiconductor element and a GaAs semiconductor element, respectively. A mullite (3Al ₂ O ₃ .2SiO ₂ ) module ₃ having a thermal expansion coefficient substantially intermediate between that of Si and GaAs is placed on a mullite module ₃ via solder balls 4.
Silica (SiO ₂ )-glass (Al ₂ O ₃ 35 wt%, MgO 14 wt%, Si
O ₂ 51 wt%) composite sintered substrate 5 and mullite-alumina (Al ₂ O ₃ ) -glass (Al ₂ O ₃ 35 wt%, MgO 14 wt%, SiO ₂
(51 wt%) A composite sintered substrate 6 is mounted, and a Si semiconductor element 1 and a GaAs semiconductor element 2 are further mounted thereon via solder balls 4. Where 3a, 5
a and 6a are conductor wirings, and 7 is a Kovar pin for input / output or power.

Next, an example of a method for manufacturing a semiconductor device of the present invention will be described. Mullite powder with an average particle size of 2.5 μm (3Al ₂ O ₃ .2SiO ₂ )
90.0 parts by weight, glass powder (Al ₂ O ₃ 3wt
%, 14 wt% of MgO, 51 wt% of SiO ₂ ), and 5.9 parts by weight of polyvinyl butyral having an average degree of polymerization of 1000 as a resin are put into a ball mill and dry-mixed for 3 hours. Furthermore, butyl butyl phthalyl glycolate 1.9 ml as a plasticizer, trichloroethylene 46.0 ml as a solvent, tetrachloroethylene 17.0 m
l, 18.0 parts by weight of hebutyl alcohol is added and wet mixed for 12 hours to prepare a slurry. Next, air bubbles are removed from the slurry by vacuum defoaming treatment, and the viscosity is adjusted. Next, the slurry is dried on a silicone-treated polyester film support using a doctor blade and then coated to a thickness of 0.23 mm, and dried through a furnace to produce a ceramic green sheet. The ceramic green sheet is detached from the silicone-treated polyester film support and cut. The ceramic green sheet thus produced is cut using a green sheet punch and a hole for guide is formed. Thereafter, the ceramics green sheet was fixed using the holes for guides, and through holes having a diameter of 0.3 mm were formed at predetermined positions by a punch method. Further, a conductive paste of tungsten powder: ethyl cellulose: polyvinyl butyral: n-butyl carbitol acetate = 79.1: 1.59: 0.61: 18.7 (weight ratio) is filled in the through-hole formed in the ceramic green sheet, and then screen printing is performed. The above-mentioned conductor paste was printed on both sides of the ceramic green sheet according to a predetermined circuit pattern. Next, this ceramic green sheet is cut, and after positioning, 120 ° C., 5 minutes, 25 kg / c
After lamination and thermocompression bonding at a pressure of m ² , the substrate was set in a substrate baking oven, heated in a mixed gas of nitrogen and hydrogen containing water at a heating rate of 200 ° C. for one hour, and heated at 1630 ° C. for 1.5 hours. The mullite module substrate 3 was manufactured by holding for a time and sintering.

In the same way, 90.0 parts by weight of mullite powder, glass powder
Five types of ceramic green sheets were prepared by adding 10.0 parts by weight, 5.9 parts by weight of polyvinyl butyral, and 10, 20, 30, 40, and 50 parts by weight of quartz powder having an average particle size of 1.0 μm, respectively.
Like the mullite module substrate, these green sheets are drilled, filled with conductors, printed, aligned from bottom to top in ascending order of the amount of quartz powder, laminated, thermocompressed, fired in the same manner as the module substrate, and baked. A semiconductor element mounting substrate 5 was produced.

In the same manner, mullite powder 90.0 parts by weight, glass powder 10.0 parts by weight, polyvinyl butyral 5.9 parts by weight,
Alumina powder with an average particle size of 1.0 μm was added to each of 10,20,30,4
Five kinds of ceramic green sheets mixed with 0.50 parts by weight are produced. These green sheets were punched, filled with conductors, printed, laminated, thermo-compressed, positioned from bottom to top in ascending order of the amount of alumina powder, and fired to produce a GaAs semiconductor element mounting substrate 6.

After Ni plating is applied to the through hole W on the lower surface of the module substrate 3, the Kovar pin 7 is connected. On the other hand, the Si semiconductor element 1 and the GaAs semiconductor element 2 are CCB-connected on the respective element mounting substrates using 95Pb-5Sr solder balls 4.

Finally, the device mounting substrate on which these devices are mounted is mounted on the module substrate by using 60Pb-40Sr solder balls 4 '.
A semiconductor device was manufactured by CCB connection. Signals and power are input and output from the pin 7 via the solder balls of the elements 4 and 4 ', the through-hole conductors 5a and 6a in the element mounting boards 5 and 6, and the through-hole conductor 3a in the module board 3. The exchange of signals between the elements is performed through the horizontal wiring 36 in the module substrate 3.

The values of the coefficients of thermal expansion of the respective parts in FIG. 1 are shown in FIG.

The module substrate 3 has a coefficient of thermal expansion intermediate between the Si element 1 and the GaAs element 2, and the element mounting substrates 5 and 6 each have a gradient of the coefficient of thermal expansion in the thickness direction.

In this semiconductor device, a Si element and a GaAs element having significantly different coefficients of thermal expansion could be mounted with high reliability in close proximity on the same module substrate. In addition, it can
The GaAs device could be mounted at a high density, and the signal propagation speed was about 1.5 times faster than the conventional device.

Embodiment 2 One embodiment of the semiconductor device of the present invention is shown in FIG. 2 as a sectional view. In FIG. 2, reference numerals 1 and 2 denote Si and GaAs semiconductor elements, respectively. Mullite having a thermal expansion coefficient close to the thermal expansion coefficient of the _{Si (3Al 2 O 3 · 2SiO} 2) - silica (SiO ₂₎ - modules made of glass _{(Al 2 O 3 35wt%,} MgO 14wt%, SiO 2 51wt%) on the substrate 3, Si semiconductor element 1 is mounted directly through the solder balls 4 ', GaAs semiconductor element 2, mullite - silica (SiO ₂₎ - alumina (Al ₂ O ₃₎ - glass (Al ₂ O ₃ It is mounted via an element mounting substrate 5 made of 35 wt%, MgO 14 wt%, SiO ₂ 51 wt%) and solder balls 4 and 4 ′. Reference numeral 6 denotes an input / output or power supply Kovar pin.

The manufacturing method is almost the same as that of the first embodiment. 90.0 parts by weight of mullite powder having an average particle size of 2.5 μm,
10 parts by weight of glass powder having an average particle size of 1.0 μm, average particle size of 1.0 μm
A starting material was obtained by adding 5.9 parts by weight of polyvinyl butyral having an average weight of 1000 to 50 parts by weight of a quartz (SiO ₂ ) powder of m.

The GaAs element mounting substrate 5 was composed of 90.0 parts by weight of mullite powder, 10.0 parts by weight of glass powder, and polyvinyl butyral 5.
9 parts by weight of quartz powder having an average particle size of 1.0 μm
Five kinds of green sheets with 5,15,5 parts by weight added, and five kinds of green sheets with 5,15,25,35,45 parts by weight of alumina powder having an average particle size of 1.0 μm, respectively, for a total of 10 kinds of green sheets These green sheets were perforated, filled with conductors, printed, aligned in the order shown above from bottom to top, laminated, hot-pressed, and fired.

The Si semiconductor element 1 was connected to the element mounting substrate on which the GaAs element was mounted, and at the same time, was connected to the module substrate by CCB using 60Pb-40Sr solder balls 4 '.

As in the first embodiment, the signal propagation speed of the present semiconductor device is about 1.5 times that of the conventional device.

Embodiment 3 An embodiment of the semiconductor device of the present invention is shown in FIG. 3 as a sectional view. In FIG. 3, reference numerals 1 and 2 denote Si and GaAs semiconductor elements, respectively. It consists of mullite (3Al ₂ O ₃ .2SiO ₂ ) -silica (SiO ₂ ) -glass (Al ₂ O ₃ 35 wt%, MgO 14 wt%, SiO ₂ 51 wt%) having a thermal expansion coefficient close to that of Si, Only the portion on which the GaAs semiconductor element 2 is mounted is an element composed of mullite-silica (SiO ₂ ) -alumina (Al ₂ O ₃ ) -glass (Al ₂ O ₃ 35 wt%, MgO 14 wt%, SiO ₂ 51 wt%). On a substrate 3 on which a mounting portion is formed, Si and GaAs elements are mounted via solder balls 4 respectively. Reference numeral 5 denotes an input / output or power supply Kovar pin.

The fabrication method is almost the same as in Examples 1 and 2. The substrate 3 was composed of 90.0 parts by weight of mullite powder having an average particle size of 2.5 μm, 10 parts by weight of glass powder having an average particle size of 1.0 μm, and 1.0 μm in average particle size.
A green sheet was prepared by adding 50 parts by weight of quartz (SiO ₂ ) powder and 5.9 parts by weight of polyvinyl butyral having an average degree of polymerization of 1000 as a starting material, and a conductor was filled and printed. After aligning and laminating this sheet, mullite powder
90.9 parts by weight, glass powder 10.0 parts by weight, polyvinyl butyral 5.9 parts by weight quartz powder having an average particle size of 1.0 μm
Five kinds of green sheets added with 45,35,25,15,5 parts by weight and alumina powder having an average particle size of 1.0 μm were added to 5,15,2, respectively.
Five kinds of green sheets with a total of 5,35,45 parts by weight were added, and a total of 10 kinds of green sheets were prepared, drilled, filled with conductors and printed, aligned in the order shown above from bottom to top, and laminated. After that, the whole was thermocompression-bonded at a time and fired.

The Si and GaAs semiconductor elements were CCB-connected on the substrate 3 using 60Pb-40Sr solder balls 4.

The signal propagation speed of this semiconductor device is about 1.6 times that of the conventional device.
It was double.

〔The invention's effect〕

Since the present invention is configured as described above, it has the following effects.

That is, a plurality of types of semiconductor elements having different coefficients of thermal expansion can be mounted on the same module substrate in close proximity and with high reliability.

As a result, the entire wiring length in the semiconductor device can be shortened, and the signal propagation speed is increased.

[Brief description of the drawings]

1, 3, and 4 are cross-sectional views of the semiconductor device of the present invention, and FIG. 2 is an explanatory diagram showing the values of the coefficients of thermal expansion of the respective parts in FIG. DESCRIPTION OF SYMBOLS 1 ... Si semiconductor element, 2 ... GaAs semiconductor element, 3 ... Module board, 3a ... Through hole wiring in module board, 3b ... Horizontal wiring in module board, 4 ... 95Pb-
5Sr solder ball, 4 '…… 60Pb-40Sr solder ball,
5 ... Si substrate mounting substrate, 5a ... Through hole wiring inside Si semiconductor device mounting substrate, 6 ... GaAs semiconductor device mounting substrate, 6a ... Through hole wiring inside GaAs semiconductor element mounting substrate, 7 ... ... Pin for input / output or power supply, 8 ...
Module substrate, 9 ... GaAs semiconductor element mounting substrate, 10
……substrate.

Continued on the front page (72) Inventor Akira Tanaka 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd.

Claims (22)

(57) [Claims] 1. A module having a thermal expansion coefficient equal to or higher than the thermal expansion coefficient of the element having the lowest thermal expansion coefficient and equal to or lower than the thermal expansion coefficient of the element having the highest thermal expansion coefficient among a plurality of types of semiconductor elements having different thermal expansion coefficients. On the substrate, a device mounting substrate having a coefficient of thermal expansion between the coefficient of thermal expansion of the module substrate and the coefficient of thermal expansion of each element, and having a gradient of the coefficient of thermal expansion in the thickness direction, is mounted. A semiconductor device having each element mounted thereon. 2. A module substrate having a thermal expansion coefficient equal to the thermal expansion coefficient of one of a plurality of semiconductor elements having different thermal expansion coefficients is directly mounted on a module substrate. Alternatively, the semiconductor element and the module substrate are mounted via an element mounting substrate having a coefficient of thermal expansion equal to the coefficient of thermal expansion of the module substrate, and other semiconductor elements are mounted on the module substrate and the coefficient of thermal expansion of the module substrate and A semiconductor device having a thermal expansion coefficient between thermal expansion coefficients and mounted via an element mounting substrate having a thermal expansion coefficient gradient in a thickness direction. 3. The semiconductor device according to claim 1, wherein no destruction due to thermal stress occurs even after 1000 cycles of a temperature cycle test from room temperature to liquid nitrogen temperature. 4. The semiconductor device according to claim 1, wherein said module substrate and said element mounting substrate are collectively laminated at the time of fabrication to form one substrate, and an element is mounted thereon. apparatus. 5. The semiconductor device according to claim 1, wherein the module substrate and a part of the element mounting substrate are integrally laminated at the time of fabrication to form one substrate. 6. A module having a thermal expansion coefficient equal to or higher than the thermal expansion coefficient of the element having the lowest thermal expansion coefficient and equal to or lower than the thermal expansion coefficient of the element having the highest thermal expansion coefficient among a plurality of types of semiconductor elements having different thermal expansion coefficients. On the substrate, each of the element mounting substrates having a uniform coefficient of thermal expansion between the value of the coefficient of thermal expansion of the module substrate and the value of the coefficient of thermal expansion of each element is mounted, and each element is mounted thereon. A semiconductor device characterized by the following. 7. The semiconductor device according to claim 6, wherein a uniform thermal expansion coefficient between the value of the thermal expansion coefficient of the element mounting substrate and the value of the thermal expansion coefficient of each element is provided on the element mounting substrate. A semiconductor device, further comprising an element mounting substrate having a coefficient of thermal expansion, and each element mounted thereon. 8. A module substrate having a thermal expansion coefficient equal to the thermal expansion coefficient of one of a plurality of types of semiconductor elements having different thermal expansion coefficients, and only the one type of semiconductor element is directly mounted. Or mounted via an element mounting substrate having a coefficient of thermal expansion equal to the coefficient of thermal expansion of the semiconductor element and the module substrate, other semiconductor elements,
On the module substrate, element mounting substrates having a uniform thermal expansion coefficient between the value of the thermal expansion coefficient of the module substrate and the value of the thermal expansion coefficient of each element are mounted, and each element is mounted thereon. A semiconductor device characterized by being mounted. 9. The semiconductor device according to claim 1, wherein the gradient of the coefficient of thermal expansion of the substrate for mounting the element is not linear, and when the element is actually mounted and operated. A semiconductor device characterized in that a thermal expansion coefficient is graded so that distribution of thermal stress in a thickness direction of an element mounting substrate becomes equal. 10. A substrate having a thermal expansion coefficient gradient in a thickness direction. 11. A substrate according to claim 4, wherein said module substrate and said element mounting substrate are laminated together. 12. The semiconductor device according to claim 1, wherein said module substrate and said element mounting substrate are multilayer wiring substrates. 13. The substrate according to claim 10, wherein
A substrate, wherein the substrate is a multilayer wiring substrate. 14. A gradient of a thermal expansion coefficient in a thickness direction, comprising laminating and sintering a plurality of green sheets comprising a plurality of components having different thermal expansion coefficients and a slightly different mixing ratio of the components. A method for manufacturing a substrate having: 15. A method for manufacturing a substrate, comprising: laminating a plurality of green sheets having the same composition, laminating a plurality of green sheets according to claim 14, and sintering. 16. A method for manufacturing a substrate according to claim 14, wherein said green sheet is perforated, printed with a conductor, laminated and sintered. 17. The semiconductor device according to claim 1, wherein said semiconductor element is sealed. 18. A semiconductor package using the substrate according to claim 10, 11, or 13. 19. An electronic computer using the semiconductor device according to claim 1. Description: 20. An electronic computer using the substrate according to claim 10, 11, or 13. 21. An electronic computer using the semiconductor package according to claim 18. 22. An electronic computer according to claim 19, wherein a cooling device of the same means is provided from the upper surface of each semiconductor element.