JP3182159B2 - Method for manufacturing multilayer wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a multilayer wiring board based on a metal wiring layer / polyimide resin interlayer insulating layer, and more particularly, to a multilayer wiring having an improved contact hole between metal wiring layers. The present invention relates to a method for manufacturing a substrate.

[0003]

2. Description of the Related Art In recent years, not only supercomputers, but also large-sized general-purpose computers, workstations, personal computers, and all other computers have been required to have high speed and large storage capacity. Have been. To meet this demand, semiconductor devices have been increasing in capacity as typified by DRAM, and ultra-high-speed elements such as GaAs and ECL have appeared.

In order to fully exploit the features of these ultra-high-speed devices and large-capacity memories, and to fully exhibit the required functions, a new mounting method is indispensable in place of the conventional mounting method on a multilayer printed circuit board. As one of the means,
As shown in cross section in FIG. 2, a polyimide resin is used for the interlayer insulating layers 1a and 1b, and a copper wiring layer using copper for the conductor wiring layers 2a, 2b and 2c, and a multilayer wiring board of a polyimide resin interlayer insulating layer system. A high-density mounting method has been developed for a semiconductor chip by a flip chip method or a TAB method. The configuration shown in FIG. 2 is based on a method (step / via) in which the position of the contact hole is shifted as the number of layers is increased without filling the inside of the contact hole.
Contact hole portions 4 for forming conductive connection portions 3a and 3b for electrically connecting between 2a, 2b and 2c indicate insulating support substrates, respectively.

However, in the above-mentioned copper / polyimide resin-based multilayer wiring board, the characteristic impedance of the signal wiring is generally required to be controlled to about 50 to 100 Ω, so that a polyimide resin insulating layer (interlayer insulating layer) is required. ) 1a, 1b is 1
A thick film of about 20 um or more per layer is required. A required contact hole 3 is formed on the thick polyimide resin layers (films) 1a and 1b, and the wiring layers 2a, 2b and 2c formed in a multilayer structure are connected via the contact hole 3. In this case, unevenness due to the contact hole 3 causes disconnection of the wiring layer and variation in characteristic impedance, resulting in deterioration of high-frequency characteristics.

In order to cope with the above-mentioned problem, as shown in FIG.
There is also known a method for filling and flattening with a and 5b to avoid a problem.

[0007]

However, in the case of the configuration shown in FIG. 3 (so-called filled via), the polyimide resin layers 1a and 1b, which are organic substances, and the contact holes 3 are used.
Due to the difference in thermal expansion coefficient between the metal pillars 5a and 5b, which are inorganic substances embedded in the inside, the metal pillars embedded in the contact holes 3 during the formation process of the multilayer wiring portion and during the reliability test of the product.
Separation occurs between the side peripheral surfaces of 5a and 5b and the polyimide resin layers 1a and 1b forming the inner wall surface of the contact hole 3, and as a result, the wirings (wiring layers) 2b and 2c are cut off. there were.

In other words, means for solving the problem of deterioration of the high-frequency characteristics and the like, in other words, embedding of the metal pillars 5a and 5b into the contact holes 3 in the multilayer wiring board of the copper wiring layer / polyimide resin interlayer insulating layer system. The method has so far not yielded good results and has been very unreliable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a contact hole formed on a very thick polyimide resin layer (film), and an electric connection between required wiring layers is formed through the contact hole. Polyimide resin that can achieve complete flattening even when multi-layer wiring with a configuration connecting to the contact hole is formed and forms the inner peripheral wall surface of the contact hole and the side peripheral surface of the metal pillar embedded in the contact hole. It is an object of the present invention to provide a multilayer wiring board which does not cause separation between the wiring board and the wiring board.

[Structure of the Invention]

[0011]

A method of manufacturing a multilayer wiring board according to the present invention comprises the steps of sequentially forming a metal wiring layer and an interlayer insulating layer made of a polyimide resin on a main surface of a supporting substrate; Forming a connection through-hole in a required interlayer insulating layer in the insulating layer; and connecting and connecting predetermined metal wiring layers by penetrating and arranging conductive metal columns in the formed connection through-hole. In the method for manufacturing a multilayer wiring board, the connection through-hole is formed to have a diameter larger than the diameter of the conductive metal column, and the conductive metal column is freely inserted through and arranged in the through-hole. The loose fitting portion is filled with a polyimide resin when the next interlayer insulating layer is formed.

That is, the present invention relates to a polyimide resin film forming the inner peripheral wall of the contact hole and the side peripheral surface of the metal pillar embedded and buried in the contact hole penetrating and arranging the conductive metal pillar for connecting the wiring layers. When forming an interlayer insulating layer after forming an upper wiring layer by providing a gap between them, it is essential to fill the gap with a polyimide resin.
The metal forming the metal wiring layer may be any metal as long as it is made of a metal usually used as a wiring material such as copper, aluminum, and gold.

[0013]

According to the present invention, a polyimide resin layer (interlayer insulating layer) forming the inner peripheral wall surface of the contact hole and the side peripheral surface of the conductive metal pillar penetratingly disposed in the through hole (contact hole) for connection.
Since a polyimide resin filled layer serving as a buffer for thermal shock is formed between the wiring layer and the wiring layer formed thereon, it is effective against thermal shock in the multilayer wiring process and high reliability is obtained. Further, even when a through-hole for connection is formed (formed) in a relatively thick polyimide resin film (interlayer insulating layer) and a multilayer wiring process is performed, complete flattening can be realized. The variation in the dance is very small and can exhibit good high-frequency properties.

[0014]

An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a cross-sectional view schematically showing an embodiment of a method for manufacturing a multilayer wiring board according to the present invention. First, for example, an alumina substrate is prepared as an insulating support substrate 4. Next, a first-layer copper wiring layer (circuit pattern) 2a is formed on the main surface of the insulating support substrate 4 by a thin film forming method such as a sputtering method and photolithography. On the surface on which the first-layer copper wiring layer 2a is to be formed, a first layer for insulating the first-layer copper wiring layer 2a and a second-layer copper wiring layer 2b to be subsequently formed in a multilayer structure is formed. An eye polyimide resin layer (interlayer insulating layer) 1a is formed (FIG. 1 (a)). After a while
The first polyimide resin layer (interlayer insulating layer) 1a
For example, a contact hole (connection through-hole) for electrically connecting the first copper wiring layer 2a and the second copper wiring layer 1b to be formed next by a selective etching method. ) 3 'is formed by drilling (FIG. 1 (b)). At this time, the contact hole 3 'penetrates through the contact hole 3' so that the conductive metal column 5a is loosely fitted (so that a gap remains between the contact hole 3 'and the inner wall surface of the contact hole 3'). It is pierced and formed so that it can be buried without contacting the inner wall surface of the first polyimide resin layer (interlayer insulating layer) 1a, in other words, to a diameter that can be arranged.

Further, an electrode film for forming a required connection metal pillar 5a by electrolytic plating is sputtered on the first polyimide resin layer 1a surface and the exposed first copper wiring layer 2a surface. , A photoresist is applied. This photoresist is patterned using a glass mask having a pattern smaller than the shape of the upper portion of the contact hole 3 '.
After removing the photoresist at the portion where the conductive metal column 5a is to be formed, the desired conductive metal column 5a is formed by electrolytic plating to the height of the upper surface of the first polyimide resin layer 1a. The removal of the resist and the removal of the electrode film are performed.

Thus, after the required conductive metal pillars 5a are freely penetrated and arranged in the contact holes 3 'formed and formed, a connection portion is formed, and then the copper wiring of the second layer is formed. layer
2b is formed on the first polyimide resin layer 1a and on the upper surface or side surface of the conductive metal column 5a (FIG. 1 (c)). Then, the first polyimide resin layer 1a is formed on the surface on which the second copper wiring layer 2b is formed, and the contact hole is formed.
In the same manner as in the case of forming the connection layer structure by forming the metal layer 3 ', the loosely penetrating and arranging of the conductive metal pillar 5a, and forming the second copper wiring layer 2b. (Interlayer insulating layer) 1b, conductive metal pillars 5b corresponding to the third copper wiring layer 2c and the second polyimide resin layer (interlayer insulating layer) 1b are freely inserted and penetrated. (Figure 1 (d)
).

Further, the above-described process is repeated for the step of forming a multilayer structure. By such a process, the side peripheral surfaces of the metal pillars 5a, 5b embedded with the contact holes 3 'formed in the polyimide resin layers (interlayer insulating layers) 1a, 1b. Contact hole 3 'in the same layer as
Each polyimide resin layer (interlayer insulating layer) 1a, 1b forming the inner wall
Is no longer in direct contact with the thermal buffer layer 6
Is formed.

In the above description, the electroplating method is used to form the conductive metal columns 5a and 5b.
Or a selective vapor phase growth method using the method described above.

[0020]

As described above, according to the method of the present invention, there has been a conventional problem in a structure in which metal pillars are embedded in a contact hole of a copper / polyimide multilayer wiring board for connection between copper wiring layers. The separation between the metal pillars and the polyimide resin insulating layer (interlayer insulating layer) is eliminated, the reliability is dramatically improved and the flattening is realized, and the high-frequency characteristics required for the substrate for mounting ultra-high-speed devices are provided. A multilayer wiring board can be easily obtained.

[Brief description of the drawings]

FIG. 1 schematically shows an embodiment of a method for manufacturing a multilayer wiring board according to the present invention, wherein a is a cross-sectional view showing a state in which a first interlayer insulating layer is formed, and b is a first sectional view. FIG. 3C is a cross-sectional view showing a state in which a contact hole (through hole for connection) is formed in a second interlayer insulating layer; FIG. 4C is a cross-sectional view showing a state in which a second copper wiring layer is formed; Sectional drawing which shows the state which formed the copper wiring layer of the eye.

FIG. 2 is a cross-sectional view illustrating a configuration of a main part of a conventional multilayer wiring board based on a copper wiring layer / polyimide resin insulating layer.

FIG. 3 is a cross-sectional view showing another essential configuration of a conventional copper wiring layer / polyimide resin insulating layer-based multilayer wiring board. 1a, 1b: interlayer insulating layer 2a, 2b, 2c: metal wiring layer (conductor wiring layer) 3, 3 ': contact hole (connection through hole) 4: insulating support substrate 5a, 5b: metal column (filled metal) 6 ... Buffer layer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05K 3/46 H05K 1/11 H05K 3/40-3/42 H01L 21/768

Claims (1)

(57) [Claims] 1. A step of sequentially forming a metal wiring layer and an interlayer insulating layer made of a polyimide resin on a main surface of a support substrate, and forming a connection through hole in a required interlayer insulating layer in the formed interlayer insulating layer. A method of manufacturing a multi-layer wiring board, comprising: a step of piercing; and a step of penetrating and arranging a conductive metal column in the formed connection through hole to connect predetermined metal wiring layers. The through hole is made larger than the diameter of the conductive metal column, and the conductive metal column is inserted through the through hole in a free-fit manner to form the next interlayer insulating layer. A method for manufacturing a multilayer wiring board, characterized in that a part is filled with a polyimide resin.