JPS5821438B2 - Ceramic splint body warmer Oyobi Sonoseizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a printed circuit board in which an electrically conductive metal thin film with strong adhesion strength is formed on a ceramic substrate.

The main purpose of this is to make it possible to form metal thin films with excellent crystallinity and adhesion on ceramic substrates using new methods, which will improve the processability of etching and electrolytic plating, and will also improve the processability of circuits. It is an object of the present invention to provide a method for manufacturing a printed circuit board that enables high density and provides a circuit board with high reliability.

Conventionally, ceramic printed circuit boards have been obtained by forming a thin film on a ceramic substrate by vacuum evaporation or sputtering.

However, with this conventional method, sufficient adhesion strength could not be obtained, and therefore a highly reliable printed circuit board could not be obtained, an excellent film quality with good crystallinity could not be obtained, and precious metals were not used. However, there were disadvantages such as low yield and high product cost.

The inventors of the present invention have carried out intensive research in order to resolve these drawbacks of conventional ceramic printed circuit boards, and as a result, have developed a ceramic printed circuit board that has strong adhesion strength by applying special physical means to the ceramic substrate. The inventors discovered a method for manufacturing a ceramic splint circuit board on which an electrically conductive metal thin film was formed, and conducted further research to complete the present invention.

Next, a detailed description of the invention An example will be explained.

An example of the apparatus used in the present invention is shown in FIGS. 1 and 2.

Without a trench, the inside of the deposition chamber 3 is 1x from IXIO 'T orr.
A vacuum of 10' Torr is maintained, and a temperature of 0.0 Torr is maintained between the crucible heater 8 and the crucible 12 containing the metal to be deposited. A DC voltage of 1 kV to 10 kV was applied with the crucible side set as positive, a current of 0.1 to IOA was applied, and 20
Heat to 0-2500℃.

In this case, as a heating method for the crucible, in addition to the method using electron impact, a method using resistance heating or induction heating may be used, or a Calothermal method that is a combination of these methods may be used.

The crucible only needs to be heated to a temperature that sufficiently evaporates the metal to be evaporated, and depending on the type of metal to be evaporated, it may even be below 1500°C.The electric power consumed between the crucible and the crucible heater is It must be sufficient to maintain temperature.

When the crucible temperature increases and the metal vapor pressure inside the crucible increases, the metal vapor is injected upward from the small hole at the top of the crucible.

The injected metal vapor is rapidly cooled by the pressure difference inside and outside the crucible, loses kinetic energy in directions other than the direction of injection, and forms clusters (massive groups of atoms) due to van der Waals forces.

The shape of the crucible may be any shape such as a cylinder, a pipe, or a box. For example, in the case of the Nissho type, the diameter of the small hole of the crucible is 1 to 30 parts of the inner diameter of the crucible, but more preferably 5 to 30 parts. This is Section 20.

If the diameter of the small hole is larger than the inner diameter of the crucible,
If the pressure difference between the inside and outside of the crucible becomes smaller, the rate of cluster generation becomes smaller, and if the diameter of the small diameter is smaller than the inner diameter of the crucible, the deposition rate will become smaller.

Next, the generated clusters are ionized by collision with electrons generated by applying a DC voltage between the red-hot ionization heater 10 and the ionization anode 9 with the ionization anode being positive, and the clusters are ionized by collision with electrons generated by applying a DC voltage between the red-hot ionization heater 10 and the ionization anode 9. 11
A voltage applied between the ionizing anode and the ionizing anode accelerates the force and deposits on the ceramics 7 of the substrate.

In this case, the DC voltage applied to the ionization heater and the ionization anode for ionization is 10 to 1000V, and the electron current for ionization is, for example, lXl0-4 Tor.
It may be 10 to 10100 O with respect to the metal vapor pressure of r, but
For ceramic substrates, the current is preferably 10 to 300 mA, and this current needs to be increased if the metal vapor pressure becomes higher.

Also, the voltage applied between the substrate electrode and the extraction electrode is 1
It is preferably 0 to 10,000 V, or preferably 100 to 5,000 V for ceramic substrates.

The ceramic substrate is deposited while moving on a guide chain from a supply section 1 to a recovery section 2.

This movement may be continuous or intermittent.

In the above method, the degree of vacuum in the deposition chamber was set to 1×1O-4To.
The reason for increasing the temperature from rr to lXl0-7 Torr is to obtain a metal film with good crystallinity and good lipid content.

In addition, metal clusters are generated by ejecting metal vapor from the small hole in the upper part of the crucible, and at the same time, the spatial distribution of the vaporized vapor and clusters is narrowed, and the rate of gold reaching the substrate is reduced.

The reason for ionizing and accelerating the injected metal vapor and metal clusters is to give energy of several 10 eV to several 1,000 eV to the metal vapor and metal 5 raster to bury metal atoms and clusters in the ceramic surface of the substrate. However, it is not possible to obtain strong adhesion strength.

Further, in order to obtain strong adhesion strength and good film quality, it is preferable to heat the ceramic substrate to 100 to 700°C.

The metal material used to generate the metal vapor here may be any metal as long as it has electrical conductivity and a temperature at which the vapor pressure of 1xlO-5 Torr is 2500°C or less.

For example, A4 Cut Pbt Cry Ni, Fe+
There may be iAu, etc., but it is not particularly limited to this.

A metal whose evaporation temperature is too high is not preferable because it will seriously damage the crucible.

The ceramic used as the substrate may be any insulating ceramic.

For example) steatite, forsterite, alumina,
Examples include feldspar, beryllia, crystallized glass, and ordinary glass.

The thickness of these substrates is not particularly limited, but a ceramic substrate having a thickness of about 0.1 van to 10 m5 is preferable for the present invention.

The thickness of the metal film can be formed to any thickness depending on the application, and the thickness is determined depending on the application, but for the purpose of the present invention, a thickness of several amps to several tens of microns is generally suitable. .

The printed circuit board created in this way can be processed into a high-performance, high-density printed circuit board using methods such as etching applied to conventional printed circuit boards, and can be used for electrical equipment, It can be used in a wide range of applications such as electronic equipment.

The ceramic printed circuit board made according to the present invention has many distinct characteristics compared to conventional ceramic printed circuit boards.

That is, (1) a pinhole-free, homogeneous electrically conductive thin film is provided on the ceramic substrate with strong adhesion strength.

The adhesion strength is good at 60 kg/i or more.

(2) Compared to conventional ceramic printed circuit boards, the density of the metal film is higher and the adhesion is stronger, making it suitable for creating fine circuits and allowing higher density circuits.

(3) Since the film is formed by applying high kinetic energy to the vapor deposited substance in a high vacuum, the film has good crystallinity and therefore good electrical conductivity.

This is advantageous in circuit design.

(4) The yield of vapor-deposited metal is very high because the space of the metal vapor is narrowed by ejecting gold and steam from the small hole in the upper part of the crucible.

This is extremely advantageous when noble metals are used as the vapor deposition material.

As described above, the ceramic printed circuit board produced according to the present invention has many flattened features, and the manufacturing method thereof is simple and highly accurate, making it an extremely effective industrial method.

Example 1 An alumina plate having a thickness of 1.0 mm was used as a substrate material, and gold was vapor-deposited using the apparatus shown in FIGS. 1 and 2.

The crucible has an inner diameter of 30 mm, a height of 307 nrlL, and 3
It has one hole of mmφ and is made of carbon.

The deposition conditions were as shown in Table 1, and gold was deposited to a thickness of 1 μm.

The printed circuit board created in this way has a homogeneous gold film with no pinholes, and has an adhesion strength of 60 kg/cm.
It showed ff1 or more.

Furthermore, using this board, it is possible to create a circuit with a minimum circuit width of 5μ.

The gold yield at this time was about 70% or more. Example 2 A 2 μm thick copper film was formed on a 20 mm thick steatite porcelain substrate under the same conditions as in Example 1.

In this case as well, a homogeneous copper film without pinholes was obtained, and the adhesion strength was 60 kg/cff1 or more.

By printing a circuit pattern on this board and etching it, a printed circuit with a minimum circuit width of 10 μm could be obtained.

Example 3 Under the same conditions as in Example 1, 2 μm of copper was deposited on a beryllia porcelain substrate with a thickness of 1.0 μm, and 1 μm of gold was plated thereon by a wet method.

The adhesion strength after gold plating was 50 kg/ff1 or more, and a good high-density printed circuit board could be obtained from this board as well.

[Brief explanation of drawings]

FIG. 1 shows an overview of the apparatus used in the present invention, and FIG. 2 shows an overview of the vapor deposition chamber. In the figure, 1 is a substrate supply section, 2 is a substrate recovery section, 3 is a deposition chamber, and 4
is a cluster ion beam generator, 5 is a substrate electrode with a built-in heating heater, 6 is a guide chain, 7 is a ceramic substrate, 8 is a crucible heater, 9 is an ionization anode,
10 is an ionization heater, 11 is an extraction electrode, 12 is a crucible, and 13 is a metal used for vapor deposition. In addition, Al-Al, A2-A2. B1-B1. B
2-B2 indicates that it is connected.

Claims (1)

[Claims] 1 In an evacuated room, a gold-side steam generation furnace with one or several sets of small holes is heated to generate metal clusters (clump-like atomic groups) from the small holes, and this metal cluster is installed in the room. The metal cluster ions are ionized by bombardment with electrons generated from an electron generator, and the generated metal cluster ions are accelerated in an atmosphere containing non-ionized metal clusters and irradiated onto the Hiramix substrate on which the metal film is to be attached. A method of manufacturing ceramic printed circuit boards by.