JPS59100262A - Palladium activating solution - Google Patents

Abstract

PURPOSE:To improve the suitability of wiring of a high m.p. metal such as W or Mo to chemical plating by treating a wet ceramic board having the wiring formed by metallizing with an alkaline aqueous soln. contg. a water soluble Pd salt, a specified Pd complexing agent and a pH adjusting agent as essential components to activate the wiring. CONSTITUTION:Wiring is formed on a clay board by printing with ink contg. a high m.p. metal such as W or Mo, and the board is calcined at a high temp. The resulting W or Mo wiring is chemically plated with an electrically conductive metal so as to reduce the electric resistance. To activate the surface of the wiring before chemical plating, the wiring is treated with an activating soln. contg. a water soluble Pd salt such as PdC2, Pd(NO3)2 or PdSO4, a Pd complexing agent represented by formula I (where n is an integer of 2-6) such as triethylenetetramine, and a pH adjusting agent such as NaOH. The activating soln. has 10-14.5pH, 10<-6>-10<-3>mol PD concn., and 2-10,000 molar concn. ratio of the complexing agent/Pd.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a wet ceramic substrate in which Vl such as tungsten, molybdenum, and real high-melting point metals are metallized, and only one line is formed on the first line. This relates to a palladium activating solution for chemical plating.

[Prior art]

Ceramic substrates include dry type substrates and erodible type substrates. The former dry-type board is a ceramic plate printed with ink containing precious metals and wired, and then fired at a temperature of 1000°C or less.Since the wiring is made of precious metals, it is difficult to use as wiring. Conductor resistance is low, and there is no corrosion of wiring.
It has good soldering properties and can be chemically plated at 0T only on the solder plate without any special activation treatment. However, it had the following drawbacks. In other words, since precious metals are used, multilayer wiring is expensive and requires separation from the multilayer wiring.

Therefore, a wet type substrate without such drawbacks was devised.

This wet type board is made of clay-like material, and is marked with 1 bl of ink containing high-melting point metals such as tungsten and molybdenum (the firing temperature is high). It forms at a temperature of about 1500'O. As a result, complicated wiring can be formed in a multilayer structure. However, this method had the following drawbacks. Since the wiring conductor is made of a metal with a melting point, (1) the conductor resistance is high; (11) it is directly connected to the IC;
Unable to solder LSI or wire bond;
etc. In order to compensate for this drawback, the surface of the fringe melting point metal is modified by plating.1. It is conceivable to reduce the conductor resistance □, solder it, or wire bond it to make it even.

This plating is done by chemical plating.

However, since high melting point metals are chemically inactive, it is necessary to activate only the melting point metal wiring before chemical plating.

As such an activating solution, I♀Kiakiaki, 55-43
Some of them are described in JP-A No. 275 and JP-A-53793129. In these, palladium is used as the activating metal.

However, it is described in Samurai Publication No. 34-8256 that palladium treatment 4 is applied to make the material suitable for chemical plating. As stated in the same publication, the special feature of the I-balloon in the Publication of Special Publication Sho SM-QS129 is that, as stated in the same publication, Pl in the activating solution is V in order to increase the amount of palladium deposited on the surface of the lVa group metal in a short time. (A palladium complexing agent that prevents palladium from precipitating in an alkaline solution because it is effective and is essentially necessary for precipitating palladium. That is, in order to deposit a large amount of palladium on IV metal, it is necessary to immerse the substrate in an alkaline solution in step 12.
It is only necessary to remove the oxidation degree and oxidation of the 1vα group, and it is sufficient to perform the activation liquid treatment for a long time, and furthermore, it is sufficient to reduce the palladium content in the activation liquid to 6. Kokai Showa 5
The prior art typified by the description in Publication No. 3-9'3129 has the disadvantage of such physical limitations.

In a weakly acidic to r-alkaline solution, palladium produces a monosulfide (or hydroxide) in the following reaction.

ld” +14jO= Pd O+2H+
・・・・・・・・・・・・(2) Once that can exist as Pd'+ (no+7/l)=tO,'・-6-2pH
4, , , , , , (2) From the above formula, hydroxyl Pr
When 4 is 13, P+d+ concentration and C is 4,5
10 mo I/e. .

On the other hand, using ethylenediaminetetraacetic acid, Pi(:13
] Total DJ in water rt3H, 10' mol/(
1(D Pd2+wo, 4.5(10+nol/l) is as follows.

il)"1.'A,'+4b" =Pd-In)TA (Generation constant: 1o, )-
・From the reaction formula (3) (ED'rA'- indicates ethylenediaminetetraacetic acid ion), pci'+ concentration in water 45 iH ([no l, /
l) Pd-11”A concentration is 10 mol
Since it can be approximated to il, the Pd" vulgarity is 4.5 x 1.
0" mo I/l, so Vkoha, gu'rA
At one time, 7 X I Ll'1ηo, 1/l is mandatory. Dissolution of ethylenediaminetetraacetic acid (or its alkali metal salt) in a water bath e, 1m01:,/
l or less. Therefore, the palladium activation solution of the prior art contains complexed palladium, ? Dium (1'd-', 1s1)TA
), it contained free palladium (Il, Pd2-'") as well as (f'dU). In order to remove this oxide, the activity Even if the solution was filtered through a filter with a porosity of 0.671 Ill before use, the following F4 (major failure N) occurred.

Squid iCll (!) Remove oxides from the activation solution using a filter with small pores Iat (-2 is also sieved/this is all that is needed to ensure that veradium oxides of 0.61n or less are present in the activation solution. When a tungsten wiring ceramic board is fully activated using this activation solution, a mountain will form for a while.

As described in Japanese Patent Application No. 14-1983-93129, since palladium precipitates on tungsten, chemical plating (for example, chemical nickel plating) is possible. The 11 particles of oxidized metal in the liquid form a layer on the ceramic 41 female other than the tungsten wiring, and this becomes the plating nucleus and causes the plating (
(hereinafter referred to as abnormal precipitation). When the plating thickness of chemical plating is thin (less than 1 μIn), the fine precipitation cannot be observed with the naked eye, but it is difficult to see the e between the interconnected objects as shown in 1.1.
It appears as a low 3-edge resistance. The thickness of chemical plating is 5
When the temperature exceeds μm11, the entire ceramic substrate becomes gray and the insulation resistance between the two thick pieces of wood becomes extremely small. That is, 1
The wet ceramic substrate wired with vσ group metal is -1-
Due to the drawbacks of the prior art as described above, it has not been possible for many people to use the technique. As of yet, there was no circuit board with wiring that could be mounted while maintaining high insulation.

[Purpose of the invention]

The purpose of the present invention is to apply palladium gold only to the α group metal wiring of the Cerahac board, and then [with a small amount of chloride plating]. It is an object of the present invention to provide a palladium activation liquid that is effective in eliminating abnormal precipitation (external precipitation) and extending life.

[Summary of the invention]

The #ridges of the palladium activation solution of the present invention are a water-soluble palladium salt, a palladium complexing agent, and a
Palladium I tongue containing L-modifier as an essential ingredient]
In the biochemical solution, N'1g of Balajiuno 1.ノ), the borrowing agent is the general formula (1), +121Q (-(:
City (−゛市1NH−人tl...(1)(here('here, n=an integer from 2 to 6) is the threshold of the ti, where it is done.This(υ palladium If the ratio is 1, preferably 10 to 14,5, the palladium concentration is ILI -1 per liter of activation.
0 (1) pa)■, and 1 mole of complexing agent/baradium
If the υrl ratio is 2 to 100 FlO, it is r4. stomach. Further, preferable water-soluble palladium salts include palladium chloride, palladium nitrate 1. Selected from 1 and 1 palladium, selected from
A preferred regulator is an alkali metal aqueous compound.

Preferably, the complexing of palladium represented by the formula (1), which plays a role in
), pentaethylenehexamine ((1, -+5)), and one or more selected from the group consisting of (1, -+5).

As a result of extensive research into complexing agents, the present inventor discovered that the complexing agent represented by the general formula (1) has extremely ambiguous behavior. child. The solution of a common compound in a water bath solution is approximately 1 mol/l fi
However, since heavy metal complexing agents are generally strong and must be treated as waste liquid, the concentration is approximately 0.2 I/l! 4-a
Ijj', Pd2''-concentration 4.5 x 10
mol/71 When the formation constant of the complexing agent that complexes with palladium is determined by referring to the formula (6) of iL above, palladium and the complexing agent combine in a molar ratio of 1:1. Those that combine with 1026.1:2 C10'', 1
: 4 and the combined weight becomes 10. Those who fully wish for this safe government (・yoammonia (1 Qib fi I J
? , = 1). As is well known, “
In ammonia C and alkali 1 biological liquids (consider the C seismic intensity), the conversion is the swimming speed, and the analysis is the national/association liquid Wj!
It cannot be put to practical use because l is not 6, has a strong odor, and is highly toxic.

As a result of examining the complexing agents of iToto, this 4-year-old solution has the general formula: r12 r4-←CtL= CJ-12NH-)-M
(1) It has been found that a compound represented by n (where n = an integer of 2 to 6) has a remarkable effect. The formation constant of this compound a with the above-mentioned palladium is not known. The original and subordinates think as follows. In an alkaline environment, a complexing agent is used to form a complex consisting of a metal ion, a complexing agent and a hydroxyl ion. Since the metal ion of the complexing agent in the second aspect of the present invention is palladium, it also forms a complex similar to the above.
The formation numbers explain the formation of palladium oxide.

The planning sample shown in FIG. 1 was prepared, and after treatment with the liquid in the test series described below, the composition of the liquid was evaluated by the 1st spot due to the stingray appearance shown in FIG.

The model of the sample shown in Fig. 1 is made by dividing the tan □ Gesten metallization into 16S squares (each side length 2, 5, hereinafter referred to as lands) on the ceramic substrate 2. It is formed as shown by reference numeral 1.

By using this substrate, the performance of the Harajikumi activating solution was evaluated in terms of the degree of precipitation by Ni plating. That is, when nickel plating was deposited on the ceramic substrate other than the valley lands, it was considered to be abnormal precipitation, and it was assumed that all of the lands were nickel plated, resulting in uneven precipitation.

Figure 2 is a diagram of the plating process for a ceramic base with 1 test 71 dots. Degreasing is done by immersing it in a caustic soda solution of 90 (11's 1oo, y, 'g for 20 minutes, and then soaking it in tap water for 10 minutes. ,
Rinse with pure water for 1 minute, activate by immersing in 60'O activating solution for 4 minutes, wash again with water under the same conditions as above, and soak in 90'O Kanizen Nyuma 5680 for 10 minutes. Then, a non-abrasive nickel plating is performed, followed by washing again with water under the same conditions as above, and drying with a dryer to complete the plating.

The test bond is heated to the specified rM in a quarter bath, with one night required for 11 vc 4 kneading (excluding washing, drying, and kneading).
I did it to the degree.

In Examples 1-5, palladium chloride was used as the palladium salt in the liquid composition containing a palladium complexing agent according to the present invention, and the effect of changing the composition once was investigated.

As shown in Table 1, □ contains 1 as palladium salt.
It was found that a concentration range of 0 to 10 mol/l is good. If the value is smaller than this ・Itα range, there will be less palladium deposited and nickel plating will precipitate, but if the value is larger than this range, the palladium salt (powder) will not be completely dissolved and will not be removed from the ceramic substrate. This caused abnormal precipitation due to pJi plating.

In Example 6.7, palladium chloride, which is a component of the palladium activating solution in Example 1, Row 4, is a palladium salt other than palladium chloride.

Palladium nitrate (implementation υ6) 1. This is an example of a test in which palladium sulfate was used instead.

From the results shown in Table IA1, palladium nitrate other than palladium chloride as an icladium salt
It can be seen that zium can also be used for one history.

Implementation 1? lJ 8-11 Test dilJ 8-11 The palladium activation of the present invention, the palladium complexing agent during the night, is N13 ((ut Cib + '4tl) H...
...+1 I heavy C in the general formula (1)
This is an example of a test designed using existing objects within the scope of the test.

1↓I in 1 bar of 1 song based on my own opinion of 1 clothes
i'T I+lb and ■・Those in the range of -2 to 6 can be used for I.

J and Shioori 12-17 Implementations Hs112-17 are based on the complexing agent/Pd concentration molar ratio in Baladyuno activation/IV of the present invention, as shown in Table 41, of the complexing agent/l'd molar ratio. There is an actual kX1 warp when changed as shown on the side.

If the 1st ratio of this ratio is small, palladium d-dide (or
41 Shigeru's ↓< This is a general guide given to the lesson of planning by iMetsu^. However, it was found that the molar ratio of complexing agent/I'd degree is 2 to 10,000C.

5-6 Kaiq Hiri 18-21 Examples 18-21 of the present invention are about the Shokyo of l'H1 direct in the case of radium activity 1 of the present invention.

As mentioned in No. 14, Si plating is Plf
It is found that precipitation becomes difficult at PI 9, and precipitation occurs properly at PI 410 to 14.5. In addition, when the measured value of Plf force was 15, the liquid turned black and became usable.

Example No. 9 22.23 shows the radium activated ISt of the present invention.
(Concerning the conventional liquid composition, which is i5 compared to human liquid)
This is a test result of C.

, 4E As shown in Table 2, tri-plating (in the case of tri-plating), palladium complexing agent is
vs, ethylenediaminetetraacetic acid disodium (Test Example 122), and glycine (Test Example 26), abnormal analysis 141 occurred in all cases.

These complexing agents are 5nfj = misfire 1! J
It is considered to be quite small compared to the formation constant of the complexing agent in J&, and I11! Ri
: According to the composition of Example 6 shown in Table 1, even if the tungsten surface is activated at a rate of 100 dm'/l without treatment of the activating solution, nickel remains. The plating was deposited normally. In addition, the ceramic substrate with molybdenum/wiring had exactly the same processing effect as Kamime's. Also, when adjusting the activation/sum chemical solution, the m-lysis rate 1v of the palladium salt is increased. For this purpose, in addition to the above complexing agents, ammonia and ammonia-loaded C
O, 0:2 +nol/l degree)/JLtteoi”
r4 yol, -t monote 4 It makes the nickel chemistry of FFA group metals noticeably more effective in long soaking life without causing any abnormal precipitation of coarse nickel.

[Brief explanation of the drawing]

Figure 1 is a front view showing the tungsten metallization on the substrate of the base of the model ceramic block, which is a sample in a practical example.
The figure is Figure 1C, in which the sample shown in Figure 1 is subjected to i'J+ plating to determine the test 1 composition solution. 1...Tungsten metallization 2...Serami! Board. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A water-bathable palladium salt, a palladium complexing agent, and a palladium active chemical solution number containing a regulator as an essential component. ”1
, F Book - Divine Ceremony (1), Mountain N GCI-12CLh NI4-÷,, if
・・・・・・・・・(1) (here, !) - 2 to an integer of O) A palladium activation liquid with 2 samurai [a] being a compound b' shown by the following. 2 Smell of my own palladium activation solution-7::, P
H is 10-14.5, palladium mystery J phlegm is 7 fortune 1
Biogenesis d; 1 [ff-'-10' mo per liter
l, and the molar concentration ratio of complexing agent/palladium is 2 to 1o.
It's ooo! Palladium activating liquid according to item 451, within the scope of item j, item 1. The above-mentioned water-based palladium salt is palladium chloride.
2. The palladium activation solution according to claim 1, which is capable of precipitating at least one selected from the group consisting of palladium nitrate, palladium sulfate, and palladium sulfate. 4. The palladium activation liquid according to any one of claims 1 to 3, when the PH and IJ4 adjuster is an alkali metal hydroxide. 5. The palladium complexing agent represented by the above general formula (1) is a group consisting of triethylene latraban (n = 5), tetraethylene pentamine (n = 4), and bentaeburene hegisamine (n = 5). The palladium oil-based liquid according to any one of claims 41 to 4, which contains one or more selected from among these.