JPS627135B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a crystalline hollow substrate particularly suitable for hybrid ICs.

Technical Background of the Invention and Problems Enameled substrates are made by coating and baking enamel on an iron plate, and can be used as a substrate for mounting hybrid ICs in the same way as conventional printed circuit boards and alumina substrates.
Used in flash valve arrays for cameras, contact plates for telephones, etc. Although the core is made of metal, it has high mechanical strength, good heat dissipation, and low cost, it has been found that it has the following drawbacks. (1) Enamel substrates that are commonly used cannot be enameled in a manner that would raise the temperature above the transformation point of the base metal, that is, approximately 900°C during the manufacturing process. This is because the crystal structure of the underlying metal changes. For this reason, below 900℃, e.g. 750 to 850
Glass frit that can be enameled at ℃ is used. This glass frit has a softening point of 550~
Since the temperature is 650℃, the temperature at which conductors, resistors, etc. for the enamel board are printed and baked on this enamel board is:
The temperature will be limited to 650℃ or less. (2) The adhesion strength between the enamel and the conductor/resistance is low. (3) Laser trimming of a resistor baked onto an enamel substrate may cause cracks in the enamel or expose the underlying core, reducing reliability. (4) A thick enamel area called a dog bone is formed in the shape of an edge at the end of the enamel substrate, reducing the printing accuracy of thick film circuits.

OBJECTS OF THE INVENTION The present invention provides an improved crystalline enamel substrate that eliminates the drawbacks mentioned above.

Summary of the Invention That is, this invention provides microcrystalline 60% of a fluorine phlogopite solid solution.
The enamel substrate is coated with a crystalline enamel consisting of 100% by weight and 0 to 40% by weight of a glassy oxide.

In this invention, the fluorine phlogopite solid solution corresponds to synthetic mica represented by the general formula MMg _3-o Al2/3n (M′M″ ₃ O ₁₀ )F ₂ .However, in the formula, n
is 3/4n21/8, M is from a group of ions having a coordination number of 12 such as alkali metals and alkaline earth metals, and M' is a coordination number of 4 such as Al, Cr, Zn, B, etc.
From a group of divalent or trivalent ions with tetrahedral coordination,
M″ is selected from the group of tetravalent ions exhibiting regular tetrahedral coordination such as Si, Ti, Ge, and Zr. 60 to 100% by weight of this synthetic mica and 40% by weight of the glassy oxide.
A formulation consisting of ~0% by weight is first prepared.

Next, this raw material mixture is thoroughly mixed and heated to melt. The heating melting temperature varies depending on the type and blending ratio of the synthetic mica and glassy oxide, but generally 1400 to 1450°C is sufficient. For details on this point, see Patent No. 564786 (toshiba application)
Please refer to .

Note that instead of using the mixture of the synthetic mica and the glassy oxide as the raw material, a mixture of the synthetic mica and a glassy oxide corresponding to the synthetic mica may be used.

The raw material components thus molten are molded into a shape that can be easily crushed later while they still have fluidity, or are pulverized to form a frit. This is heated again to a temperature of 750-1100°C. By this reheating treatment, microcrystals of synthetic mica precipitate from the initially transparent material, which increases hardness, strength, etc., and becomes an opaque ceramic-like material.

Examples of the synthetic mica having _the above general formula that can be used here include KMg _3/2 Al(AlSi ₃ O ₁₀ )F ₂ and K _0.8
Ba _{0. 1} Mg _9/4 AL _1/2 (Al _{0. 9} Cr _{0. 1} Si ₃ O ₁₀ ) F ₂ ,
KMg _3/8 Al _7/4 (BSi ₃ O ₁₀ ) F ₂ , KMg _3/4 Al _3/2
There are many compounds such as (AlSi ₂ . ₉ Ti ₀ . ₁ O ₁₀ )F ₂ , and these may be used alone or in a mixture of two or more. Here, in the synthetic mica component
If Al that has partially substituted Mg is outside the range of 3/4 to 21/8 atoms, it will be difficult to form into glass and the workability will be poor.
It is necessary to keep it outside the range of Al3/4 to 21/8 atoms that have partially substituted Mg. Glassy oxides that can be used as other components include, for example, PbO, SiO ₂ , B ₂ O ₃ , P ₂ O ₅ , K ₂ O, Na ₂ O,
Oxides that easily vitrify when solidified after melting, such as CaO, are preferred. Furthermore, if the blending ratio of these two components exceeds the above range, that is, if the weight ratio of the glass component to the synthetic mica component exceeds 40%,
Although it is possible to vitrify by heating and mixing, it is extremely difficult to precipitate synthetic mica by reheating treatment.
Exceeding the above range is not preferable.

Next, 20 parts by weight or less of the frit obtained by crushing this ceramic material is added to 100 parts by weight.
Oxides such as Fe, Co, Mn, and Ni that strengthen the bond between the enamel and the iron plate are added, and enamel is applied using normal glazing methods such as spraying, electrodeposition, and dipping.900
Bake at a temperature below ℃. In order to strengthen the bond between the enamel and the underlying metal, in addition to the usual nickel-melting treatment, the underlying metal may be blasted or underglazed.

Incidentally, the amount of crystals in the above-mentioned frit may be adjusted appropriately, and the frit obtained by pulverization may be used without reheating. In addition, this enamel board is further heated to 750 to 900℃.
The amount of crystals may be increased by performing heat treatment at a temperature of . Here, the expansion coefficient of the enamel layer is preferably selected to be lower than that of the base iron core in order to increase its mechanical strength.

In the crystalline enamel substrate obtained as described above, the enamel is made of microcrystals of a fluorine phlogopite solid solution, and various drawbacks of ordinary enamel substrates are eliminated. The softening temperature of this enamel increases,
The adhesion strength between the enamel and the thick-film conductor has also increased, improving mechanical workability and making grinding, polishing, cutting, etc. possible. For example, polishing has made it possible to obtain a smooth substrate with no dog bones and high printability. become able to. In addition, the trimming performance by laser is also improved, but if the amount of crystals is less than 60%, classics are likely to occur in the glassy part due to trimming, and the resistance value change will be 0.5% after 10,000 hours in a normal atmosphere.
This is not desirable as it exceeds the Therefore, it can be seen that a composition range of 60 to 100% by weight of microcrystals of the fluorine phlogopite solid solution and 40 to 0% by weight of the glassy oxide is an appropriate range. By selecting the expansion coefficient of the crystalline enamel, the base metal is not limited to iron, but may be other metals or alloys such as copper and stainless steel.

Examples of the invention Examples will be described below.

K _{0.8 Ba 0.1} Mg _9/4 Al _1/2 ( _{Al 0.9} Cr _{0.1 Si 3 O 10} )
300g of _F2 and glass powder ( _SiO2 30%, _{B2O3 30} %,
Mix well the mixture with 150g of BaO (40%) and melt it uniformly by keeping it at 1450°C in an alumina porcelain crucible. After this, pour it out in a thin layer while it is still fluid. Next, this is placed in a furnace, and the furnace temperature is gradually raised to 850°C at a rate of about 50°C per hour, held at about 850°C for one hour, and then ground into a powder of 325 mesh or more.

3 g of Fe ₂ O ₃ per 100 g of the obtained powder,
A slurry containing 0.5 g of CoO, 0.5 g of NiO, 1.0 g of MnO ₂ , 150 c.c. of isopyl alcohol, and 50 c.c. of butyl carbitol was blasted onto the surface using a conventional spray method, and then electroless Enamel is applied to the surface of nickel-metalized low carbon steel at 880℃. Next, the temperature is maintained at 850°C to grow crystals.

Effect of the invention The crystalline enamel on the obtained enamel substrate is
A line analysis revealed that a fluorophlogopite solid solution had precipitated, and the amount of crystals reached 85% by weight. The softening point of this enamel is 750°C or more, which is more than 100°C higher than the enamel difficulty point of a normal enamel substrate, which is 550 to 650°C. The adhesion strength between the enamel and the conductor, resistor, etc. has been improved by more than 1.5 times compared to conventional ones, and the trimming of the resistor can be done using a laser, similar to the trimming of the resistor on an alumina substrate. The reliability of the resistor is also as high as that of alumina substrate resistors that are laser trimmed on an alumina substrate. In addition, since it has good mechanical workability, it can be ground and polished, and it facilitates the mass production of small substrates by punching and cutting from large substrates. Sho Kenmaro allows the dogbone to be smoothed, making high-precision printing and mounting easier.

Such a crystalline enamel substrate of this invention,
By eliminating the drawbacks of conventional hollow substrates and improving mechanical workability and reliability, we have created a hybrid
It has become excellent for IC mounting, etc.

Claims (1)

[Claims] 1 60-100% by weight of microcrystals of fluorine phlogopite solid solution
and 0 to 40% by weight of a glassy oxide.