JP3454765B2 - Precious metal catalyst removal solution - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noble metal-based catalyst remover used for electroless plating and the like, and more particularly to a printed circuit board, an electronic device mounting package, a semiconductor device, an electronic display such as LCD, EL, PDP, and an IC.
The present invention relates to a noble metal-based catalyst removing liquid suitable for removing the above-mentioned noble metal-based catalyst when forming a metal wiring using a chemical plating catalyst in the production of electronic devices such as cards.

[0002]

2. Description of the Related Art Conventionally, for example, electroless plating using a chemical plating catalyst containing a noble metal such as Pt or Pd has been applied to the formation of a metal wiring board. Since these noble metal-based catalysts themselves have conductivity, and catalyst residues remaining in the parts other than the circuit formation may cause a decrease in reliability such as migration characteristics, they must be removed by some method. Is required. For this reason, for example, in the manufacture of a metal wiring board by the subtractive method, the catalyst residue was simultaneously removed by etching during circuit formation.

[Problem] However, in the conventional method, if the etching treatment time is lengthened, the metal wiring itself is also dissolved, so that the etching treatment time cannot be sufficiently lengthened and the required catalyst removal effect can be improved. could not. Also, as a removing solution for dissolving and removing the catalyst residue, a removing solution containing an acid has been developed, but since it has excessive corrosiveness, it corrodes the object to be applied and the object to be applied such as electroless plating species is limited. Therefore, a noble metal-based catalyst removing liquid which is not preferable in use and has milder or less corrosive properties has been desired. Further, with the recent miniaturization and high density of various electronic components, improvement in resistance characteristics between metal wirings, such as insulation, is required. Therefore, it is required to more completely remove catalyst residues. There is.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the above-mentioned conventional technique. The technical problem specifically set for this solution is the electroless plating method. It is possible to efficiently and completely remove precious metal-based catalysts that are not originally needed, such as the removal of catalyst residues during the production of wiring boards that use, and to limit the applicable objects such as electroless plating species. It is to provide a noble metal-based catalyst removal liquid that does not exist.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above problems can be effectively solved by using a solution containing a specific compound. I arrived. That is, the noble metal catalyst removal liquid according to claim 1 of the present invention is characterized by containing at least one selected from glutamic acid, glutamate, and glycine hydrochloride. And it is desirable that it further comprises thiouric acid.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The noble metal catalyst removal liquid according to this embodiment is at least 1 selected from the group consisting of ethylenediamine, ethylenediamine salt, glutamic acid, glutamate, citric acid, citrate, sulfite, nitrite, thiourea, and glycine hydrochloride. The seed is dissolved or dispersed in a solvent. The noble metal catalyst is a general term for platinum group metals of Ru, Rh, Pd, Os, Ir and Pt, gold, silver and compounds containing these metal elements.

Examples of ethylenediamine and ethylenediamine salt include ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid monoammonium, ethylenediaminetetraacetic acid diammonium, ethylenediaminetetraacetic acid triammonium, ethylenediaminetetraacetic acid monolithium, ethylenediaminetetraacetic acid dilithium and ethylenediaminetetraacetic acid. Trilithium, ethylenediaminetetraacetate tetralithium, ethylenediaminetetraacetate monopotassium, ethylenediaminetetraacetate dipotassium, ethylenediaminetetraacetate tripotassium, ethylenediaminetetraacetate tetrasodium, ethylenediaminetetraacetate monosodium, ethylenediaminetetraacetate disodium, ethylenediaminetetraacetate trisodium , Ethylenediaminetetraacetic acid tetrasodium, ethylenediaminetetraacetic acid dicalcium, ethyl Diamine tetraacetate two barium, ethylenediaminetetraacetic acid magnesium, disodium ethylenediaminetetraacetate strontium can be exemplified ethylenediamine dihydrochloride.

As glutamic acid and glutamate, L-glutamic acid, D-glutamic acid, L-
Glutamate hydrochloride, D-glutamate hydrochloride, L-lithium hydrogen glutamate, lithium hydrogen D-glutamate, lithium L-glutamate, lithium D-glutamate, sodium L-glutamate, sodium D-glutamate, sodium L-glutamate, D
Examples thereof include sodium glutamate, potassium L-glutamate, potassium D-glutamate, potassium L-glutamate, potassium D-glutamate, calcium L-glutamate, and calcium D-glutamate.

Further, citric acid and citrate include citric acid, ammonium citrate (triammonium citrate, diammonium monohydrogen citrate, ammonium dihydrogen citrate), lithium citrate (trilithium citrate, citric acid). Dilithium monohydrogen acid, lithium dihydrogen citrate), sodium citrate (trisodium citrate, disodium monohydrogen citrate, sodium dihydrogen citrate), potassium citrate (tripotassium citrate, dihydrogen monocitrate) Potassium, potassium dihydrogen citrate),
Examples include magnesium hydrogen citrate and calcium hydrogen citrate.

Further, as sulfites, ammonium sulfite, lithium sulfite, sodium sulfite, potassium sulfite, ammonium hydrogen sulfite, lithium hydrogen sulfite,
Examples thereof include sodium hydrogen sulfite and potassium hydrogen sulfite. Further, examples of the nitrite include lithium nitrite, sodium nitrite, potassium nitrite and the like. Furthermore, thiourea and glycine hydrochloride can be preferably used. These components may be used alone or in combination of two or more.

The above-mentioned solvent used in the above-mentioned noble metal-based catalyst removing liquid is not particularly limited, and may be any solvent as long as it can dissolve or disperse the above-mentioned components. Examples of those satisfying these conditions include water, alcohols such as methanol, ethanol and 1-propanol, and cellsolves such as methylcellosolve, ethylcellosolve and butylcellosolve. Among them, water is preferably used. be able to. These solvents may be used alone or in combination of two or more as needed.

The contents of the components in the noble metal catalyst removal liquid with respect to the solvent are not particularly limited, and can be arbitrarily changed depending on the type of solute and the type of object to be treated such as metal wiring material. Further, the solute does not have to be completely dissolved except when it is treated by spraying or the like.

When the noble metal-based catalyst is removed using this removing solution, the object to be treated may be immersed in the removing solution, and the dipping method, spraying method, showering method, or other general-purpose process may be used. Can be used.
Of these, it is desirable to perform rocking in the dip method.

Further, the above-mentioned dipping may be carried out not only by dipping in one kind of removing liquid but also by dipping in several kinds of removing liquid in sequence. The removal liquid temperature and the immersion time during the removal treatment are not constant because they vary depending on the removal liquid component, but the removal liquid temperature is high (desirably 20 ° C. or higher is preferable) and the removal effect improves as the immersion time increases. preferable.

[0015]

EXAMPLES The present invention will be described in more detail below with reference to examples. [Example 1] 10 parts of sodium sulfite to 89 parts of water,
1 part of disodium ethylenediaminetetraacetate was mixed and dissolved to prepare a noble metal catalyst removal liquid of Example 1.

On the other hand, on a roughened resin substrate (roughness Ra = 3 μm) (Via Lux manufactured by Du Pont), a precious metal catalyst liquid (OPL-80 manufactured by Okuno Seiyaku) containing a noble metal such as Pd was used. To form a noble metal catalyst layer and activate it using an accelerator (OPL-555 manufactured by Okuno Chemical Industries Co., Ltd.). The resin substrate having the activated noble metal catalyst layer was immersed in the noble metal catalyst removing liquid of Example 1 heated to 80 ° C. for 15 minutes,
It was washed with water and dried.

The obtained substrate was placed in an electroless nickel solution ICP Nicoron GM (manufactured by Okuno Chemical Industries Co., Ltd.) heated to 80 ° C.
After immersion for an hour, electroless plating was tried, but no nickel deposition was observed on the substrate. In addition, separately, quantitative analysis of the amount of palladium on the substrate that has been subjected to the catalyst removal treatment,
When using total reflection X-ray fluorescence, the amount of palladium was
It was 4.4 × 10 ⁸ atoms / cm ² , and it was found that almost no palladium remained.

[Example 2] 5 parts of ethylenediaminetetraacetic acid dipotassium was mixed and dissolved in 95 parts of water, and Example 2-
A noble metal catalyst removal solution of No. 1 was prepared. On the other hand, 3 parts of sodium hydrogen sulfite was mixed and dissolved in 97 parts of water to prepare a noble metal catalyst removal solution of Example 2-2.

On the other hand, on a resin substrate (epoxy resin manufactured by Sumitomo Bakelite Co., Ltd.) which has been subjected to a roughening treatment (roughness Ra = 3 μm),
Precious metal catalyst liquid containing Pd (CP 33 manufactured by Japan Energy Co.)
16) was used to form a noble metal catalyst layer, which was then activated using an accelerator (CP4044 manufactured by Japan Energy Co., Ltd.). The resin substrate having the activated noble metal catalyst layer was immersed in the noble metal catalyst removing solution of Example 2-1 heated to 80 ° C. for 20 minutes, and subsequently heated to 80 ° C. in Example 2-2. It was immersed in the noble metal catalyst solution for 20 minutes, washed with water, and dried at 60 ° C. For the obtained substrate,
Electroless plating was attempted by immersing in electroless nickel solution ICP Nicoron GM (manufactured by Okuno Chemical Industries Co., Ltd.) heated to 80 ° C for 1 hour, but no nickel deposition was observed on the substrate.

Example 3 87 parts of water was mixed with 10 parts of L-glutamic acid hydrochloride and 3 parts of thiourea to prepare a noble metal catalyst solution as in Example 3. Palladium catalyst solution SOC-PA (manufactured by Sumitomo Osaka Cement Co., Ltd.) was applied on an alumina plate, and the substrate with catalyst obtained by firing at 135 ° C for 20 minutes was used.
20 in the precious metal catalyst solution of Example 3 heated to 80 ° C.
Soaked for a minute. Then, the catalyst activator (OPC
-555) and then activated. The obtained substrate was washed with water, dried at 60 ° C, and immersed in electroless nickel solution ICP Nicoron GM (Okuno Pharmaceutical Co., Ltd.) heated to 80 ° C for 1 hour to try electroless plating. No nickel deposition was observed.

[0021]

As described above, the noble metal-based catalyst removing liquid according to claim 1 of the present invention contains at least one selected from glutamic acid, glutamate, and glycine hydrochloride, for example, it is dipped. The noble metal catalyst can be easily and completely removed by a simple method. For example, migration characteristics can be improved and the density of metal wiring can be increased, which provides highly reliable and smaller electronic devices. can do. In addition, since the noble metal catalyst is removed by a mechanism different from the method using the conventional acid-based removal solution or the etching-based catalyst removal method, it has been necessary to remove the noble metal-based catalyst using the acid-based catalyst removal solution. The present invention can be applied to an object to be applied such as an electroless plating species (for example, a copper alloy) that could not be processed. Further, the same effect can be obtained by including thiouric acid according to claim 2.

Continuation of the front page (56) Reference JP-A-8-139435 (JP, A) JP-A-10-284825 (JP, A) JP-A-53-91381 (JP, A) JP-A-2000-178752 (JP, A) JP 11-200060 (JP, A) JP 62-230990 (JP, A) JP 59-100596 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) ) C23C 18/18 H05K 3/26

Claims (2)

(57) [Claims] 1. A glutamic acid, glutamate, noble metal catalyst remover, characterized in that it contains at least one selected glycine hydrochloride from. 2. A contract further comprising thiouric acid.
The precious metal-based catalyst removal liquid according to claim 1.