TW201038766A - Method of electroless gold plating over miniature circuits on substrate - Google Patents

Abstract

A method of electroless gold plating over miniature circuits on a substrate, firstly by removing residual organic materials from the substrate and then submerging the substrate to increase its surface wettability, so that when the substrate to be plated is placed in a gold plating bath, by means of adjusting the temperature and the concentration to activate the gold ions in the gold plating bath to allow the gold ions to be normally deposited on the surface of the metal circuits to be plated, thus a gold plating layer of even thickness can be formed by means of chemical reactions without having to add a step of setting an isolating layer. In particular the gold plating bath is low toxic since cyanides are not added, but the carboxyl compounds and salts of the carboxyl compounds are utilized as the deposition stabilizer of the gold plating bath to allow the gold ions to have high stability, high deposition rate and high adhesion, therefore it is specifically suitable for being used over the substrate having miniature circuits.

Description

201038766 VI. Description of the invention: [Technical field to which the invention pertains] - A method of moneyless gold, in particular, a method of plating a uniform thickness of a metal layer on a micro-scale line. [Prior Art] Due to advances in the manufacturing technology of integrated circuits, the manufacturing of the 〇25 micro 以下 以下 line is the mainstream of the current metallization process. As the size of the line is shrinking, how to efficiently form a substrate for forming a conductive material on a substrate having a minute size is an important key to development. The electroplating process is a technology that is filled with a small-sized circuit, and the electroplating is to immerse one piece of the object to be plated in an ionic solution containing electric ore metal to make the cathode and anode in the power supply and the electric clock slot. (Consumable or non-consumptive) Electrical connection, at the same time, the electroplated metal is placed on the anode, and the workpiece to be placed on the cathode is filled with a 0-metal thin film layer on the surface of the object to be deposited. ★ The thickness of the ore layer is always an important indicator for evaluating Wei performance. Referring to Figure 2, the prior art does not use the substrate mineralization method of the isolation layer, wherein the substrate A is provided with a substrate B, and when the substrate B is placed in the gold plating, the gold plating operation is performed. 'If there is no barrier layer on the outside of the substrate B (see the second figure of f), then the gold ion is on the substrate B, and the gold-plated layer c on the substrate B will not form. Stable semicircular bulge. Referring to the second figure, the schematic diagram of the gold plating method of the substrate using the isolation layer of the prior art 'the traditional sheet metal bath is provided with the substrate B on the button A, and the substrate B is made of metal, in the traditional key gold method. , will be on the substrate a on the outer side of 201038766 & g, paste oxidation! g, dioxin or photoresist to form a barrier layer Aj ' and can form a gold-plated space above the substrate b and in the gold During the process, the gold ions are freed and filled into the gold-plated space crucible, and stacked into a square-gold shape, and then the chemical layer is used to remove the separator A1 from the substrate a, that is, the gold plating operation on the substrate β is completed. However, the shortcoming of the prior art is that the method of electroplating gold is easy to form a gold-plated layer with uneven thickness. The plating has high and low currents, which may cause uneven thickness. In addition, the gold-plated bath must be preset before gold plating. Isolation 〇 | 'And then remove the isolation layer, in addition to the trouble and inconvenience of the reliance on gold, also increase the cost of materials and extend the processing time of the entire process, so it is necessary to rely on each other A method of forming a gold plating layer of uniform thickness on a minute-sized line. SUMMARY OF THE INVENTION The main object of the present invention is an electroless gold plating method on a micro-sized circuit of a substrate, comprising: providing a substrate to be plated, the substrate to be plated having at least one surface to be plated, the at least one surface to be plated Having a patterned metal line to be plated, the at least one surface to be plated of the substrate to be mined is cleaned in a cleaning manner to remove the organic substance remaining on the at least one surface to be plated, and the cleaning method can be a plasma cleaning method or a cleaning liquid cleaning method, wherein the cleaning liquid may be at least one of a water-soluble surfactant of at least twenty carbons or a solution containing a water-soluble organic solvent; The plated substrate is immersed in at least one of pure water, at least 85% aqueous surfactant or a salt aqueous solution to increase the surface wettability of the at least one surface to be plated of the substrate to be plated; The substrate to be plated is immersed in a gold bath, wherein the gold plating bath comprises at least one water-soluble gold compound, at least one gold mismatch, 201038766 agent, at least one carboxyl compound a salt thereof, wherein the at least one carboxyl compound or a salt thereof may be oxalic acid, malonic acid, succinic acid, butenedioic acid, valeric acid, lactic acid, glycolic acid, gluconic acid, citric acid, malic acid At least one of tartaric acid and its salts. Therefore, the present invention can solve the shortcomings of the conventional technology, and achieve a method of forming a gold-plated layer having a uniform thickness on a minute-sized line by virtue of the interaction of chemical components without requiring electrification and isolation layers, thereby effectively saving manufacturing costs. And manufacturing time. [Embodiment] The embodiments of the present invention will be described in more detail below with reference to the drawings and the reference numerals, which can be implemented by those skilled in the art after studying this specification. Referring to the second figure, the schematic diagram of the electroless gold plating method on the micro-sized circuit of the substrate of the present invention, together with the fourth figure, the substrate of the electroless gold method on the micro-sized circuit of the substrate of the present invention. schematic diagram. The present invention relates to a method for plating a uniform thickness metal layer on a micro-sized line by chemical gold, as shown in step S10 of the third figure, and in conjunction with the fourth figure, first providing a substrate 1 to be plated, The substrate to be plated 1 has at least one surface 11 to be plated, and the surface to be plated 11 has a patterned metal line 3 to be plated, wherein the substrate 1 to be mirrored may be a copper foil substrate, a substrate, and a arsenic. a gallium substrate, a gallium nitride substrate, a ceramic substrate, a glass substrate or other suitable substrate, and the metal on the surface of the metal to be plated 3 may be gold, platinum, palladium, Silver, nickel, copper, a gold alloy, a platinum alloy, a handful of alloys, a silver alloy, a nickel alloy, a copper alloy or other suitable alloy. 201038766 Next, as shown in step S20, the surface of the to-be-poor surface to be treated is subjected to 仃μ treatment to remove the surface to be plated, and the chemical ore treatment is continued, wherein - the appropriate cleaning side: the surface to be plated of the substrate 1 to be mined 11 _ treatment, the appropriate cleaning method = is: electric material washing method, - cleaning liquid cleaning method or other suitable, monthly washing method, the cleaning liquid contains at least no more than twenty carbon water-soluble interface Thieves - solutions containing sisters or other suitable solutions.

The cleaning liquid cleaning method can send the waiting board to a washing machine (not shown) for cleaning, the cleaning machine can be horizontal, washing machine, dipping machine, flushing machine A machine or a one-piece washer, and the water wash temperature can range from 6 〇卞 to 2 〇〇卞. Referring to Figure 5, a schematic view of the wetting of the electroless gold method on the micro-sized lines of the substrate of the present invention. And proceeding to step S3, the pre-dip wetting treatment is performed on the substrate 1 to be plated to increase the surface wettability of the surface 11 to be plated of the substrate to be plated, thereby improving the quality of the subsequent electroless gold plating. The substrate 1 to be immersed is immersed in a pure water, a surfactant containing at least 85% of water, a salt solution or other suitable solution. As shown in FIG. 5, the substrate 1 to be plated may be immersed in the solution having the above solution. At least one of the tanks 4 is inside. The surfactant in the surfactant containing at least 85% by water may be poly(vinyl pyrrolidone), polyethylene glycol, or polypropylene glycol (P〇ly (propylene glycol)). The surfactant in at least one of the copolymers thereof and at least 85% or more of the surfactant is present in an amount of from 0.1 to 30 g/l. .201038766 wherein the δ hai salt aqueous solution may be sodium sulphate, potassium chloride, sodium phosphate, sodium dihydrogen phosphate (such as ship plus Phosphate) at least one of Potassium phosphate and one pot of monopotassium phosphate - see Figure 6 for electroless gold on the micro-sized lines of the substrate of the present invention. A schematic diagram of an electroless gold bath of the method. Next, proceeding to step 34, the immersion substrate 1 is immersed in a gold plating bath 5, and the gold plating bath 5 is heated to a temperature ranging from 110 °F to 175T. It is noted that the present invention The gold plating bath 5 does not need to be energized, but the chemical reduction between the elements on the surface of the metal line 3 to be plated and the composition of the gold plating bath promotes stable, rapid forward deposition of gold ions in the gold plating bath 5. On the surface of the metal line 3 to be plated, a gold plating layer 31 having a uniform thickness is formed. Wherein the electroless gold plating bath 5 comprises at least one of a water soluble gold compound, at least one gold complexing agent and at least one carboxyl compound or at least one salt of a carboxyl group compound, wherein the water soluble gold compound may be monochlorinated. 5克/升。 The gold, the content of the water-soluble gold compound is 2. 0~4. 5 g / liter. The at least one slow-acting compound may be oxalic acid, propanedionic acid, butaned ionic acid, butyric acid, pentaned ionic acid, lactic acid, At least one of a glycolic acid, a gluconic acid, a citric acid, a hydroxybutanedioic acid, a tartaric acid, and a salt thereof. 201038766, the gold bath 5 in the mine can be further set up a loop through the device (the surface is not shown) 'the base Hx makes the concentration of the plating surface 5 shop evenly. Another phase to be plated substrate 1 Lin gold bath 5 The amount of rock shake is 4 -12 meters / minute, which can drive the gold ions to self-distribute on the surface of the metal line 3 to be plated, so that the thickness of the gold plating layer 31 is more uniform. In summary, the residual organic matter is removed by cleaning, and the metal line 3 to be recorded after the substrate is infiltrated can increase the surface wetness, so when the frequency is set to 1 _ gold oblique, _ temperature financial adjustment, The gold ions in the gold plating bath 5 are intensified, so that the gold ions are positively deposited on the gold wire of the metal wire to be mined, so that the step of providing the insulating layer is not to form a uniform thickness through chemical reaction. Gold-plated f 'especially gold-plated bath 5 does not contain cyanide, so gold-plated bath 5 is low 毋 14 ' and uses the sulfhydryl compound and the salts of the ruthenium compound, the gold surface of the gold bath 5 to make gold Ions have high stability, aglow rate and adhesion, so they are especially suitable for substrates with tiny size lines. The above is only a preferred embodiment for explaining the present invention, and is not intended to limit the present invention in any way, so that any of the inventions in the spirit of the same invention can be used. Modifications should still be included in the scope of the invention as intended. 201038766 [Simple description of the drawing] ^The figure is a dry plating method of the substrate which is not used in the prior art. The second figure shows the gold plating method of the substrate using the isolation layer of the prior art. Electroless gold plating on the size line The third figure is a schematic flow chart of the minute method of the present invention for the substrate. The fourth figure is a schematic view of the substrate of the electroless gold plating method on the micro-sized line of the substrate of the present invention. "

The fifth figure is a schematic diagram of the wetting of the electroless gold method on the micro-sized line of the substrate of the present invention. "V The sixth figure is a schematic diagram of the electroless gold plating bath of the electroless gold forging method on the micro-sized line of the substrate of the present invention. 201038766 [Description of main components] S10, S20, S30, S40 Step 1 Substrate to be plated 11 To be mined 3 Metal to be plated 31 Gold plated 4 Slot 5 Gold plated bath A Substrate B Substrate C Mineral gold layer A1 Isolation layer All gold-plated space

Claims (1)

Jinming satin, one silver, one recorded, one copper, one gold alloy, one I white alloy, one palladium alloy, one silver alloy, one nickel alloy, or one copper alloy at least 201038766 VII. Patent application scope: 1. One type The electroless gold plating method on the micro-sized circuit of the substrate comprises: providing a substrate to be plated, the substrate to be plated having at least one surface to be plated, and the at least one surface to be plated has a patterned metal line to be plated; - cleaning method to at least - the (four) row of the substrate to be cleaned to remove the organic material remaining on the at least one surface to be plated, the cleaning method may be a plasma cleaning method or a cleaning liquid cleaning method At least one of - wherein the cleaning solution may be at least one of a water-free surfactant of at least twenty carbons or a solution containing a water-soluble organic solvent; immersing the substrate to be plated in - pure water - at least 85% or more of the surfactant or the salt-like water lining - at least the towel -1, the surface wettability of the at least one surface to be plated of the briquetting substrate is increased; and the substrate to be plated is immersed Plated In the bath, wherein the gold plating bath comprises at least one of a water-soluble gold compound, at least a gold-like compound, and at least one of a base compound or a salt of the at least one carboxyl compound, wherein the at least one species The compound may be at least one of grass gn acid, succinic acid, tauene acid, sebacic acid, lactic acid, glycolic acid, gluconic acid, citric acid, malic acid, tartaric acid, and salts thereof. 2. The method of claim 1, wherein the substrate to be plated is a copper foil substrate, a germanium substrate, a gallium arsenide substrate, and a nitride. At least one of a gallium substrate, a ceramic substrate or a glass substrate. 3. The method of electroless gold plating on a micro-sized line of a substrate as described in the scope of claim 1, wherein the metal on the surface of the metal line to be plated may be one of 201038766. 4. The electroless gold plating method on the micro-sized line of the substrate according to item 1 of the application scope, wherein the surfactant in the surfactant containing at least 85% of the water may be polyvinylpyrrolidone, At least one of polyethylene glycol, polypropylene glycol or a copolymer thereof, and the surfactant content in the surfactant containing at least 85% or more of water is 〇·1 -3 g/l. 5. The electroless gold plating method on the micro-sized line of the substrate as described in item 1 of the application scope, wherein the salt aqueous solution may be sodium chloride, potassium monochloride, sodium hydrogen monophosphate, monophosphate. At least one of sodium dihydrogenate, potassium hydrogen monophosphate, and potassium dihydrogen phosphate. 6. The method of electroless gold plating on a micro-sized line of a substrate according to item 1 of the application, wherein the water-soluble gold compound may be at least one of gold monochloride, gold sulfite or gold monothiosulfate. 5克每升。 The water content of the water-soluble gold compound is 2. 0-4. 5 g / liter. 7. The electroless gold plating method on the micro-sized line of the substrate as described in the first item of the application, wherein the gold plating bath 5 is heated to a temperature ranging from 11 〇卞 to 175 °F. 8. The electroless gold plating method on the micro-sized line of the substrate according to item 1 of the application scope, wherein a circulation filter is further disposed in the gold plating bath. 9. The method of electroless gold plating on a micro-sized line of a substrate as described in claim 1, wherein the plated material to be plated has a plated amount of 4 to 12 meters per minute. 12