【発明の詳細な説明】[Detailed description of the invention]
（産業上の利用分野）
本発明はセラミツクスの表面粗化法に関する。
（従来の技術とその問題点）
セラミツクスの表面粗化法として、セラミツク
スの表面をHF、HBF4等で処理して粗化する方
法、NaOH、KOH等の溶融アルカリで処理して
粗化する方法がある。
セラミツクスの表面を粗化した後無電解めつ
き、さらに必要に応じて行なう電解めつきでセラ
ミツクス上に直接金属被膜を析出させ、エツチン
グなどの方法で導体配線を形成してセラミツク配
線板とされるが、前者の方法で粗化すると金属被
膜とセラミツクスとの密着力が弱く金属被膜にふ
くれが発生するという欠点が生じ、後者の方法で
は金属被膜とセラミツクスとの密着力にばらつき
（良好な密着力を有するものと、密着力が弱いも
のとが存在）が多く、また無電解銅めつきの厚さ
が1μｍを越えると金属被膜にふくれが発生し、
使用に耐えないという欠点がある。
本発明は上記した欠点が生じないセラミツクス
の表面粗化法を提供することを目的とするもので
ある。
（問題点を解決するための手段）
本発明者らは上記の欠点について種々検討した
結果、上記のような粗化法ではセラミツクス表面
のフラツクス（ガラス質）と主構成物質粒子（ア
ルミナセラミツクスであればアルミナの粒子）の
ごく一部を粗化するだけで主構成物質粒子の粗化
が不十分であるため上記の欠点が生じるというこ
とをつきとめ、セラミツクスをNH4F、
（NH4）2SO4、H2SO4及びH2Oを含む混合溶液中
に浸漬し、ついで十分に水洗した後NaOH融液
中に浸漬したところセラミツクスの表面が均一に
粗化できるということを見出した。
本発明はセラミツクスをNH4F、（NH4）2SO4、
H2SO4及びH2Oを含む水溶液中に浸漬し水洗後、
NaOH融液中に浸漬するセラミツクスの表面粗
化法に関する。
本発明における混合溶液は、粗化するセラミツ
クスの成分により異なるが、大略NH4Fを30〜60
重量％、（NH4）2SO4を１〜10重量％、H2SO4を
５〜20重量％及びH2Oを10〜64重量％の割合で
配合した混合溶液で用いることが好ましく、さら
に必要に応じHF、HBF4、HCl、NaCl等を添加
してもよい。
また上記の混合溶液中へのセラミツクスの浸漬
時間は、液温が30〜90℃の溶液中に１分以上浸漬
することが好ましい。
NaOH融液はNaOHの融点以上の温度で加熱
することにより得られる。なお加熱温度の上限に
ついては特に制限はないが、費用及び作業性の点
で600℃であることが好ましい。
NaOH融液中へのセラミツクスの浸漬時間は、
上記の温度に加熱した融液中に30秒以上とするこ
とが好ましい。
なおNaOH融液中への浸漬は必要に応じ２回
以上行なつてもよい。
NaOH溶液の中和液としては、H2SO4、
H3PO4、HCl等が用いられる。
（作用）
セラミツクスは、第１段階でNH4F、
（NH4）2SO4、H2SO4及びH2Oを含む混合溶液か
ら発生するフツ化水素酸により徐々にセラミツク
ス表面のフラツクスと主構成物質粒子のごく一部
が化学的にエツチングされ、粗化されたセラミツ
クス表面がが形成される。さらに水洗した後第二
段階でNaOH融液によりセラミツクス表面の主
構成物質粒子の微細なエツチングが行なわれ、均
一に粗化されたセラミツクス表面が形成される。
（実施例）
以下実施例により本発明を説明する。
実施例 １
アルミナセラミツク基板（日立化成工業製、商
品名ハロツクス552、寸法80×80×厚さ0.8mmを脱
脂液（日立化成工業製、商品名HCR201）で洗浄
し、乾燥後NH4F10ｇ（40.5重量％）、
（NH4）2SO41ｇ（4.1重量％）、濃H2SO42ml（14.9
重量％）及びH2O10ml（40.5重量％）の混合溶液
（液温70℃）中に10分間浸漬して粗化を行なつた。
ついで流水中で十分に水洗し、乾燥後350℃に加
熱したNaOH融液中に１分間浸漬して再粗化を
行なつた。その後濃度10％のH2SO4溶液中に５
分間浸漬し、超音波（出力300W）による振動エ
ネルギーを付与し、セラミツクス表面を中和し、
ついで水洗を行ない無電解銅めつきを３時間行な
い厚さ7μｍの銅の被膜を形成した。なお無電解
めつき液はPH12.4で第１表に示す組成のものを用
いた。
(Industrial Application Field) The present invention relates to a method for surface roughening ceramics. (Conventional techniques and their problems) Methods for roughening the surface of ceramics include a method of roughening the surface of ceramics by treating it with HF, HBF 4 , etc., and a method of roughening the surface of ceramics by treating it with a molten alkali such as NaOH, KOH, etc. There is. After roughening the surface of the ceramic, a metal film is directly deposited on the ceramic by electroless plating and then electrolytic plating if necessary, and conductor wiring is formed by methods such as etching to make a ceramic wiring board. However, the former method has the drawback that the adhesion between the metal coating and ceramics is weak and blistering occurs when the metal coating is roughened, while the latter method has the disadvantage that the adhesion between the metal coating and ceramics varies (good adhesion is not good). There are many types of copper plating (some with strong adhesion and others with weak adhesion), and when the thickness of electroless copper plating exceeds 1 μm, blistering occurs in the metal coating.
The drawback is that it cannot withstand use. The object of the present invention is to provide a method for surface roughening ceramics that does not suffer from the above-mentioned drawbacks. (Means for Solving the Problems) As a result of various studies on the above-mentioned drawbacks, the present inventors have found that the above-mentioned roughening method causes flux (vitreous) on the surface of ceramics and particles of the main constituent material (even if it is alumina ceramics). It was discovered that the above drawbacks occur because the roughening of the main component particles is insufficient even if only a small portion of the particles ( e.g., alumina particles) are roughened.
(NH 4 ) 2 SO 4 , H 2 SO 4 and H 2 O were immersed in a mixed solution, then thoroughly washed with water and then immersed in a NaOH melt, the surface of the ceramic could be uniformly roughened. I found out. The present invention uses ceramics as NH 4 F, (NH 4 ) 2 SO 4 ,
After immersing in an aqueous solution containing H 2 SO 4 and H 2 O and washing with water,
This paper relates to a surface roughening method for ceramics immersed in NaOH melt. The mixed solution in the present invention differs depending on the components of the ceramics to be roughened, but approximately 30 to 60% of NH 4 F is contained in the mixed solution.
It is preferable to use a mixed solution containing 1 to 10% by weight of (NH 4 ) 2 SO 4 , 5 to 20% by weight of H 2 SO 4 and 10 to 64% by weight of H 2 O. Furthermore, HF, HBF 4 , HCl, NaCl, etc. may be added as necessary. Further, it is preferable that the ceramics be immersed in the above-mentioned mixed solution for 1 minute or more in a solution having a liquid temperature of 30 to 90°C. NaOH melt is obtained by heating at a temperature above the melting point of NaOH. There is no particular restriction on the upper limit of the heating temperature, but 600° C. is preferable in terms of cost and workability. The immersion time of ceramics in NaOH melt is
It is preferable to immerse the melt in the melt heated to the above temperature for 30 seconds or more. Note that immersion into the NaOH melt may be performed two or more times as necessary. As a neutralizing solution of NaOH solution, H 2 SO 4 ,
H 3 PO 4 , HCl, etc. are used. (Function) Ceramics generates NH 4 F,
Hydrofluoric acid generated from a mixed solution containing (NH 4 ) 2 SO 4 , H 2 SO 4 and H 2 O gradually chemically etches the flux on the ceramic surface and a small part of the main constituent material particles. A roughened ceramic surface is formed. After further washing with water, in the second step, the main constituent material particles on the ceramic surface are finely etched using the NaOH melt to form a uniformly roughened ceramic surface. (Example) The present invention will be explained below with reference to Examples. Example 1 An alumina ceramic substrate (manufactured by Hitachi Chemical Co., Ltd., trade name Halox 552, dimensions 80 x 80 x thickness 0.8 mm) was cleaned with a degreasing liquid (manufactured by Hitachi Chemical Co., Ltd., product name HCR201), and after drying, 10 g of NH 4 F (40.5 weight%),
(NH 4 ) 2 SO 4 1 g (4.1% by weight), concentrated H 2 SO 4 2 ml (14.9
Roughening was performed by immersing the sample in a mixed solution (liquid temperature: 70° C.) of 10 ml (by weight %) and H 2 O (70° C.) for 10 minutes.
Then, it was thoroughly washed under running water, dried, and then immersed in a NaOH melt heated to 350° C. for 1 minute to perform re-roughening. Then 5% in H 2 SO 4 solution with concentration 10%.
The ceramic surface is immersed for a minute, and vibration energy is applied using ultrasonic waves (output 300W) to neutralize the ceramic surface.
Then, it was washed with water and subjected to electroless copper plating for 3 hours to form a copper film with a thickness of 7 μm. The electroless plating solution used had a pH of 12.4 and a composition shown in Table 1.
【表】
めつき後感光性レジストフイルム（日立化成工
業製、商品名PHT−862F−40）を使用し、一般
的なエツチング法により寸法２×２mmのパターン
を形成し、試料30ケについて密着（接着）強度を
測定した。その結果2.5〜4.0Kg／mm2の密着強度を
示し良好であつた。また外観を観察したが銅の被
膜にふくれは見られなかつた。
比較例 １
実施例１と同じアルミナセラミツク基板を実施
例１と同じ脱脂液で洗浄し、乾燥後40℃で濃度10
％のHF溶液に20分間浸漬して粗化を行なつた。
ついで濃度10％のNaOH融液中に５分間浸漬し
て中和した。その後水洗し、以下実施例１と同様
の方法で無電解銅めつきを行ない、ついで密着強
度を測定した。その結果密着強度は0.5Kg／mm2以
下で測定できないものが数個あつた。また外観を
観察したところ銅の被膜全面にふくれが発生して
いた。
比較例 ２
実施例１と同じアルミナセラミツク基板を実施
例１と同じ脱脂液で洗浄し、乾燥後500℃に加熱
したNaOH融液に５分間浸漬して粗化を行なつ
た。ついで濃度10％のH2SO4溶液中に５分間浸
漬して中和した。その後水洗し、以下実施例１と
同様の方法で無電解銅めつきを行ない、ついで密
着強度を測定した。その結果密着強度は最大が
3.5Kg／mm2で最小が０とばらつきが多かつた。ま
た外観を観察したところ銅の被膜の所々にふくれ
が発生していた。
（発明の効果）
本発明によればセラミツクスの表面を均一に粗
化することができ、セラミツクスの表面に導体配
線を形成しても導体配線すなわち金属被膜とセラ
ミツクスとの密着力が良好で、またふくれが発生
せず極めて好適である。[Table] Using a photosensitive resist film (manufactured by Hitachi Chemical Co., Ltd., product name PHT-862F-40) after plating, a pattern with dimensions of 2 x 2 mm was formed by a general etching method, and 30 samples were closely attached ( Adhesion) strength was measured. The results showed good adhesion strength of 2.5 to 4.0 Kg/mm 2 . The appearance was also observed, and no blistering was observed in the copper coating. Comparative Example 1 The same alumina ceramic substrate as in Example 1 was cleaned with the same degreasing solution as in Example 1, and after drying, it was heated to a concentration of 10 at 40°C.
% HF solution for 20 minutes to roughen the surface.
Then, it was immersed in a 10% NaOH melt for 5 minutes to neutralize it. Thereafter, it was washed with water, electroless copper plating was performed in the same manner as in Example 1, and then the adhesion strength was measured. As a result, there were several cases in which the adhesion strength was less than 0.5 Kg/mm 2 and could not be measured. Further, when the appearance was observed, blistering had occurred on the entire surface of the copper coating. Comparative Example 2 The same alumina ceramic substrate as in Example 1 was washed with the same degreasing solution as in Example 1, dried, and then immersed in a NaOH melt heated to 500° C. for 5 minutes to roughen it. It was then immersed in a 10% H 2 SO 4 solution for 5 minutes to neutralize it. Thereafter, it was washed with water, electroless copper plating was performed in the same manner as in Example 1, and then the adhesion strength was measured. As a result, the adhesion strength is maximum
There was a lot of variation with the minimum being 0 at 3.5Kg/ mm2 . Further, when the external appearance was observed, blistering had occurred in some places on the copper coating. (Effects of the Invention) According to the present invention, the surface of ceramics can be uniformly roughened, and even when conductive wiring is formed on the surface of ceramics, the adhesion between the conductive wiring, that is, the metal coating, and the ceramic is good, and It is extremely suitable as no blistering occurs.