JPH04273193A - Method of coating through hole - Google Patents

Abstract

PURPOSE:To provide a formation method of a film in a through-hole which allows deposition substance to deposit without irregularities on a wallside of the through hole of a substrate and improves reliability and producibility of film formation in the through hole in a formation method of a film in the through hole by vacuum deposition. CONSTITUTION:A deposition substance 19 is deposited inside a through hole of a substrate 16 while changing an angle of the substrate 16 to a deposition source 17 and deposition is continued for a fixed time; then, the deposition substance 19 extends throughout inside the through hole of the substrate 16 without irregularities and a part without deposition is eliminated. Accordingly, reliability improves and a film in the through hole can be formed in one deposition operation, thereby producing effects on improvement of producibility and cost down.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a film on a through hole that provides conduction between the front and back sides of a substrate constituting an electronic circuit.

0002

2. Description of the Related Art Electrical continuity between both surfaces of a substrate is achieved by forming a conductive film on the walls of a through hole provided in a substrate. A method for forming a conductive film on the wall surface of the through hole includes a vacuum evaporation method in which an electrode material is applied to the wall surface of the through hole by vacuum evaporation.

FIG. 4 shows an apparatus used in a conventional vacuum evaporation method, in which a dome-shaped substrate holder 2 is attached inside a dome-shaped vacuum chamber 1 to cover the upper part of the vacuum chamber. The structure is such that a board 3 can be attached to the board 3.

A substrate 3 having through holes is attached to the substrate holder 2, and a vapor deposition source 4 is placed in the center of the lower part of the vacuum chamber 1.

Next, the air in the vacuum chamber 1 is exhausted from the exhaust pipe 5 to create a vacuum inside the vacuum chamber 1, and the vapor deposition material 6 for forming a conductive film is scattered in the vacuum chamber 1 from the vapor deposition source 4, and the substrate 3 is A conductive film is formed on the wall surface of the through hole by vapor deposition in the through hole provided in the through hole.

[0006]

[Problems to be Solved by the Invention] In such a conventional vapor deposition method, the positional relationship between the substrate 3 and the vapor deposition source 4 is constant, and the vapor deposition substance 6 flying onto the substrate is directed in a fixed direction with respect to the substrate surface. Since the particles only fly from the surface, there are parts in the through hole 7 where no coating is formed. 5 shows a cross section of the through hole 7, and FIG. 6 shows a plan view of the through hole 7. The arrow is
The direction in which the vapor deposition material 6 flies and the shaded area indicate locations where the coating is formed.

Furthermore, in order to reduce unevenness in the film thickness of the vapor deposition material 6, the dome-shaped substrate holder 2 is often rotated by a rotating shaft 8 provided at the top of the vacuum chamber 1, as shown in FIG. However, even in that case, since the flying angle to the substrate is constant, a portion of the through hole 7 shown in FIGS. 5 and 6 that is not evaporated remains.

[0008] Therefore, it is necessary to change the mounting angle of the substrate 3 and carry out the vapor deposition in several steps, which increases the time and effort of the vapor deposition process and causes an increase in cost.

[0009] This invention was made to solve the above-mentioned problems, and the vapor deposition material is evenly deposited on the wall surface of the through hole of the substrate, and the entire wall surface of the through hole is coated in one vapor deposition operation. An object of the present invention is to provide a method for forming a film on a through hole, which can form a film, and improves the reliability and productivity of film formation on the through hole.

0010

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention deposits a deposition material into the through holes of a substrate while changing the angle of the substrate with respect to the deposition source. This is a method of forming a film of

[0011]

[Operation] Evaporation is performed while changing the angle of the substrate with respect to the evaporation source, so by continuing to evaporate for more than a certain period of time, the evaporation material is deposited evenly within the through holes of the substrate.
It is possible to eliminate portions that are not deposited.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a vacuum evaporation apparatus used in the method of forming a film on a through hole according to the present invention, in which a dome-shaped vacuum chamber 11 has a rotatable shaft A inserted from the outside, and a rotary shaft A inserted from the outside. A holder 12 fixed to a rotation axis A is provided, and the holder 12 is further provided with a rotatable rotation axis B. A substrate holder 13 is attached to the inner end of the rotation axis B, and a substrate holder 13 is attached to the inner end of the rotation axis B. Wheels 15 are attached to the rails 14 on a circumferential track fixed to the rails 14 .

Although there are two substrate holders 13 shown in FIG. 1, the number of substrate holders is arbitrary, and a larger number of substrate holders may be provided.

A substrate 16 on which a film is to be formed is attached to this substrate holder 13, and a vapor deposition source 17 to be vapor deposited is placed in the center of the lower part of the vacuum chamber 11. Next, the air inside the vacuum chamber is exhausted from the exhaust pipe 18, the inside of the vacuum chamber 11 is evacuated, and the vapor deposition material 1 is
9 is scattered in the vacuum chamber 11 and deposited on the substrate 16.

During this vapor deposition operation, the holder 1 is rotated by the rotating shaft A.
When the vacuum tank 2 is rotated, the wheels 15 rotatably attached to the holder 12 move while contacting the rails 14 fixed to the vacuum chamber 11 as the wheels 15 rotate, and the wheels 15 perform rotational motion.

Due to the rotation of the wheel 15, the substrate holder 13, which is fixed to the rotation axis B like the wheel 15, also rotates around the rotation axis B, and the substrate 16 rotates in synchronization with the rotation of the substrate holder 13. Rotate.

As the substrate 16 rotates, the substrate 16
The direction of the evaporation source 17 as viewed from above changes, and the flying direction of the evaporation material deposited on the substrate also changes with time.

In this way, as shown in FIG. 2, the angle at which the vapor deposition substance 19 flies to the through hole 20 of the substrate 16 changes with time, and if the vapor deposition continues for more than a certain period of time, the inside of the through hole 20 will not be vapor deposited. There will be no parts left.

[0020]

[Effects of the Invention] As described above, according to the present invention, the angle of the substrate attached to the substrate holder in the vacuum chamber with respect to the evaporation source changes with time, so that the evaporation material is distributed evenly onto the wall surface of the through-hole of the substrate. The reliability of film formation on through holes has been improved by vapor deposition, and it has become possible to form a film on the entire wall surface of the through hole in a single vapor deposition process, making the process of forming a film on through holes much easier. This has the effect of improving productivity and reducing costs.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a vacuum evaporation apparatus used in carrying out the method of the present invention.

FIG. 2 is a cross-sectional view showing how a conductive film is formed in a through hole by the method of the present invention.

FIG. 3 is a plan view showing how a conductive film is formed in a through hole according to the method of the present invention.

FIG. 4 is a cross-sectional view of a vacuum evaporation apparatus used for forming a conductor film in a through hole according to a conventional example.

FIG. 5 is a cross-sectional view showing how a conductive film is formed in a through hole according to a conventional example.

FIG. 6 is a plan view showing a state in which a conductive film is formed in a through hole according to a conventional example.

[Explanation of symbols]

11 Vacuum chamber 16 Board 17 Vapor deposition source 20 Through hole

Claims (1)

[Claims] 1. A method for applying evaporation to a through-hole, characterized in that a evaporation source and a substrate having a through-hole are housed in a vacuum chamber, and evaporation is performed on the wall surface of the through-hole in the substrate while changing the angle of the substrate with respect to the evaporation source. Film formation method.