JPS61230395A - Hybrid multilayer interconnection substrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hybrid multilayer wiring board, and particularly to a hybrid multilayer wiring board with an improved coverland structure.

2. Description of the Related Art Recent developments in electronic devices have been remarkable, and in the design and manufacture of semiconductor devices, especially ICs, LSIs, etc., there is a trend toward smaller devices and higher integration. Therefore, by increasing the degree of integration of the device and giving a degree of freedom in coupling between each element arranged within the substrate, it is possible to realize high-density packaging that conforms to the general trend seen in the development of each of the above-mentioned glaze devices. Multilayer wiring technology is attracting attention as a powerful technology.In addition, in order to increase the density of electronic circuits on substrates, technology that stacks circuits to create multiple layers is also widely used, such as multilayer ceramic substrates. They are manufactured by green sheet lamination method, printing lamination method, thick film multilayer method, etc., and are becoming increasingly dense and highly reliable.

By the way, in the implementation of electronic equipment that requires high-speed, large-capacity processing, such as large-scale computers, it is necessary to develop technology that simultaneously increases the density of wiring and increases the speed of signals propagating within the wiring. has been done.

In other words, in computers, communication devices, etc., the demands for higher performance and smaller size have almost been satisfied on the system side due to the development of Fi, especially LSI element technology, and the operation delay time of logic elements has been shortened. Delay time has an important meaning in LSI implementation, and its reduction has come to be viewed as extremely important for the entire system.

Therefore, as a mounting technology that satisfies this mounting surface, especially the high-density wiring, and the high speed of signals propagating within the wiring, a large number of LSI chips etc. are arranged on a ceramic substrate, and the mutual interaction between them is achieved. A configuration in which wiring is performed inside and on the substrate is attracting attention.

That is, a so-called hybrid multilayer wiring board in which a ceramic wiring board mainly accommodates power wiring and on which fine signal wiring patterns are formed using thin film technology is expected to satisfy the above requirements.

Problems to be Solved by the Invention The conventional hybrid multilayer wiring board has a structure in which one thin film multilayer wiring 20 is formed on a ceramic wiring board section 10, as shown in FIG.

A cover land 23 is formed on the surface of the ceramic substrate for connection between the through hole 12 provided in the ceramic substrate 11 and the thin film wiring pattern 22.

The diameter of the through hole 12 is usually 0.1 due to industrial constraints.
~0.2 mm, and since it is necessary to cover the opening of this through hole, the cover land 23 is usually a circular pattern with a diameter of 0.2 mm or more, or a rectangular or polygonal pattern of the same size. It is said that Organic resin, glass ceramic, etc. are used as the insulating material 21 of the thin film multilayer wiring section 20, but since the formation of these insulating materials requires a heating and baking process at 300° C. to 900° C., the cover land 23 is thin and the conductive material is mainly made of common gold or hooks, internal stress arises from the difference in thermal expansion coefficient between the ceramic substrate 11 and the cover land 23 and from through holes. The cover land often peels off from the ceramic substrate during the heating and firing process due to the ejection of residual gas.

One of the conventional techniques for preventing this peeling of the coverland is to use a coverland material mainly made of tungsten or molybdenum, which has a small difference in coefficient of thermal expansion from ceramic. Because its electrical resistance is several times higher than that of gold or copper, it has a high speed of signal propagation.
The drawback is that it cannot be used for the required signal wiring or power supply wiring that carries large currents.

Another conventional technique for preventing peeling of the cover land is to form the cover land using a thick film technique using a conductive paste that has good adhesion to ceramics. Because the dimensional accuracy of the completed pattern is inferior to that of the conventional technology, the thin film multilayer wiring section 20
It has the disadvantage that it is easy to cause misalignment.

Therefore, the development of a multilayer wiring board that satisfies both high-density packaging and high-speed signal propagation by solving the various drawbacks of the conventional technology described above will improve the performance of various devices that enable high-speed, large-capacity processing. further improves the implementation of 7 performance,
This is important in increasing reliability. The object of the present invention is also to provide a multilayer wiring board, particularly a hybrid multilayer wiring board with an improved cover land structure.

Means for Solving the Problems The hybrid multilayer wiring board of the present invention includes a ceramic wiring board having through holes, a thin film wiring pattern formed thereon, and a connection between the through holes of these boards and the thin film wiring pattern. A hybrid multilayer wiring board having a cover land for electrical connection, wherein the cover land is formed on the surface of the ceramic wiring board by a thin film method, and has a fine pattern in the form of a lattice, mesh, or stripe. It is characterized by being divided.

Furthermore, it is possible to have a thin film wiring section including one or multiple wiring layers formed as necessary on the upper layer of the cover land.

In the hybrid multilayer wiring board of the present invention, the fine wiring pattern of the cover land can be formed of a metal or alloy with good conductivity such as Au, Ag, or Cu. Various thin films are produced by forming a predetermined thin film pattern using plating methods, various chemical vapor deposition methods (CVD methods), physical vapor deposition methods (PVD methods) such as sputtering methods, and then subjecting them to heat treatment (annealing). Formation methods are available.

Further, a thin film multilayer wiring section including a wiring layer is formed on the upper layer of the cover land, and polyimide resin, glass, ceramic, thermosetting epoxy resin, etc. can be advantageously used as the material for the insulating layer in the present invention. .

Formation of this thin film wiring pattern can be carried out by conventionally known multilayer wiring technology, and is not particularly limited. That is, general photolithography technology, various thin film formation methods,
Select and combine various etching methods as appropriate 5! It is possible to apply

Example Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1(a) is an enlarged plan view showing the cover land portion in the first embodiment of the present invention;
) is a cross-sectional view taken along line A-B&I.

In this embodiment, the cover land 3 is a mesh pattern formed on the through hole 2 and surrounded by a ground wiring network 4.

In this example, the mesh pattern is composed of three cover lands, fine line segments with a line width of 60 micrometers and an edge-to-edge distance of 40 micrometers, and is mainly composed of an electrolytic gold plating film with a thickness of 6 micrometres. It is formed as. A thin film multilayer wiring section is formed on the upper f@ of this cover land 3 by forming a polyimide resin insulating layer in a heating process at 400°C.
Because the internal stress generated in the pattern is mesh-like,
Don't concentrate in the center. In addition, through-hole 2 is removed during the heating process.
The residual gas ejected from the mesh also passes through the mesh, so no peeling of the coverland occurs.

Before the application of the present invention, the cover land was a solid pattern with the same dimensions as in this embodiment, but the reduction rate of the conductor area of the cover land by applying the present invention was 16%, which is lower than that of the film. When the thickness is constant, the resistance value increases by 19%, and this increase in resistance value is not a problem in most cases, and in this example, the film thickness of electrolytic gold plating was 7.5 microns. It is also possible to prevent the resistance value from increasing by setting it to meters.

FIG. 2 is a plan view showing a 20th embodiment of the present invention.

This example is a case of a grid-like cover land with a line width of 50 micrometers and a distance between lines of 100 micrometers.

FIG. 3 is a plan view showing a third embodiment of the present invention.

This example is a case of a striped cover land with a line width of 60 micrometers and a distance between lines of 40 micrometers.

In any of the above three embodiments, the conductor is limited to an electrolytic gold-plated film, but a copper-plated film or a silver-plated film may also be used.
In addition, the present invention is effective for insulating materials that require a heating process, including polyimide resins. Examples of insulating materials for which the present invention is effective other than polyimide resins include glass and ceramic bases. Examples include thermosetting epoxy resins.

Effects of the Invention As explained in detail above, the present invention prevents peeling of the cover land during the heating and firing process by forming the cover land formed on the ceramic substrate into a lattice-like, mesh-like, or striped pattern. There is an effect that can be done. Therefore, it is possible to provide a high-performance and highly reliable hybrid multilayer wiring board that is useful in mounting electronic devices that require high-speed, large-capacity processing.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are a plan view and a sectional view showing a first embodiment of the present invention, respectively, and FIG. 2 is a whistle 2 of the present invention.
FIG. 3 is a plan view showing a third embodiment of the present invention, and FIG. 4 is a sectional view of a conventional hybrid multilayer storage board. In the figure, 1...ceramic substrate, 2...
... Through hole, 3 ... Mesh cover land, 4 ... Ground distribution network, 5 ... Grid cover land, 6 ... Stripe cover land, 10
...Ceramic wiring board section, 11...
Ceramic substrate, 12...Through hole, 13
...Ceramic board inner layer wiring, 14... ...Input/output bin, 20...Thin film multilayer wiring section,
21... Insulating material, 22... Thin film wiring,
23...Cover land. Figure 1 Figure 4

Claims (1)

[Claims] a ceramic wiring board having multiple through holes;
A plurality of wiring layers each having a thin film wiring pattern laminated on the substrate, and a plurality of cover lands divided into fine patterns in the form of a lattice, a mesh, or a stripe and formed on the through holes of the substrate by thin film technology. The above-mentioned hybrid multilayer wiring board comprising: