TW202243561A - Electroless nickel immersion gold manufacturing method and system capable of reducing chemical processing steps capable of reducing the consumption of cleaning water and various chemicals and reducing expenditure costs - Google Patents

Abstract

An electroless nickel immersion gold (ENIG) manufacturing method capable of reducing chemical processing steps includes steps of: horizontally conveying circuit boards sheet by sheet to perform acid cleaning, water washing, micro-etching, water washing, sand blasting, ultrasonic cleaning, water washing, pre-acid leaching, water washing, pre-leaching, activation, water washing, post-acid leaching, and water washing; flipping the circuit boards vertically and moving the same sheet by sheet to perform electroless nickel deposition, water washing, electroless gold deposition, and recovery water washing; and then flipping the circuit boards sheet by sheet and horizontally conveying the same to perform water washing, blowing, and drying. The system used is composed of an acid cleaning tank, a first washing tank, a micro-etching tank, a second washing tank, a sand blasting tank, an ultrasonic cleaning tank, a third washing tank, a pre-acid leaching tank, a fourth washing tank, a pre-leaching tank, an activation tank, a fifth washing tank, a post-acid leaching tank, a sixth washing tank, an electroless nickel deposition tank, a seventh washing tank, an electroless gold deposition tank, a recovery water washing tank, an eighth washing tank, a blowing tank, and a drying tank arranged in series and side by side, accordingly, the invention is able to complete the surface treatment of circuit boards using only one system.

Description

Electroless nickel-gold process method and system capable of reducing chemical processing steps

The invention relates to the technical field of circuit board manufacturing, in particular to a process and system used in electroless nickel and gold.

Electroless Nickel/Immersion Gold (Electroless Nickel/Immersion Gold, abbreviated as ENIG, also known as chemical nickel gold, immersion nickel gold or electroless nickel gold) replaces palladium on the surface of copper through a chemical reaction, and then chemically deposits a layer of nickel on the basis of the palladium core. Phosphorus alloy layer, and then a layer of gold is replaced on the surface of nickel by displacement reaction. Electroless nickel gold is mainly used for surface treatment of circuit board subsequent assembly process.

The treatment process of the chemical nickel gold process in the circuit board processing includes: pre-treatment, chemical deposition and post-treatment. The pre-treatment steps include: brushing→water washing→sandblasting→water washing→ultrasonic cleaning→microetching→water washing→pickling→water washing→drying→drying. The steps of chemical deposition include: cleaning → water washing → microetching → water washing → pre-acid leaching → water washing → pre-soaking → activation → water washing → post-acid leaching → water washing → chemical deposition of nickel → water washing → chemical deposition of gold → water washing → drying. The post-processing steps include: pickling→water washing→ultrasonic cleaning→water washing→drying→drying.

Therefore, the system used in the conventional chemical nickel-gold process must include three sets of equipment, namely pre-processing equipment (as shown in Figure 1A), chemical deposition equipment (as shown in Figure 1B) and post-processing equipment (as shown in Figure 1C ). The pre-treatment equipment includes: brushing tank 101, washing tank 102, sandblasting tank 103, washing tank 104, ultrasonic cleaning tank 105, micro-etching tank 106, washing tank 107, pickling tank 108, washing tank 109, drying tank 110 , Drying tank 111. After the circuit board is purified, the circuit board must be manually placed in a hanging basket 200 one by one.

Chemical deposition equipment includes: cleaning tank 121 and several washing tanks 122, micro-etching tank 123 and several washing tanks 124, pre-acid dipping tank 125, washing tank 126, pre-soaking tank 127, activation tank 128, washing tank 129, exchange tank 130 , post-acid leaching tank 131, water washing tank 132, chemical deposition nickel tank 133, number washing tank 134, chemical deposition gold tank 135, number washing tank 136, drying tank 137. The production operation method is to move the hanging basket 200 with multiple pieces (for example, 20~40 pieces) of circuit boards, using two cranes, the first moving vehicle 201 and the second moving vehicle 202, to move between the aforementioned reaction tanks in sequence, Drive the hanging basket 200 to rise or fall vertically. After the hanging basket 200 is sequentially moved to the exchange slot 127 by the first crane trolley 201 , it will be taken over by the second crane trolley 202 to move to the subsequent reaction chamber for operation.

The post-processing equipment includes: a pickling tank 141 , a water washing tank 142 , an ultrasonic cleaning tank 143 , a water washing tank 144 , a drying tank 145 , and a drying tank 146 . In the post-processing process, it is still necessary to manually take out the circuit boards one by one from the hanging basket 200, and place them in the equipment to perform related operations in sequence.

Based on the above, in the above three processing processes, such as pre-treatment, chemical deposition and post-treatment, a large amount of cleaning water and chemical solutions must be used. Not only is the cost high, but also the recovery and reprocessing of waste water after use is another cost. In addition, manpower must be used to remove or move the circuit board in the hanging basket, which is time-consuming and labor-intensive.

The previous process of the chemical nickel gold process is the green paint (Solder Mask) process. The circuit board will have a baking process at the end of the green paint process. The temperature is 180 degrees Celsius and the baking time is 50 minutes. Putting the circuit board aside temporarily may take several hours to a day, and the surface of the circuit board will be more oxidized and polluted by the environment. Therefore, when the circuit board is undergoing the chemical nickel-gold process, there will be brushing, sandblasting, micro-etching, acid Washing and other procedures to remove the oxide layer on the surface of the circuit board. Furthermore, the conventional chemical nickel-gold process is divided into three processing processes: pre-treatment, chemical deposition, and post-processing. Between each processing process, there will be a waiting period of time and the problem of manual handling and contact will cause the surface of the circuit board to oxidize and pollute. Therefore, in the process of chemical deposition and post-treatment, procedures such as micro-etching, pickling or ultrasonic cleaning are added in the early stage of the process to remove the oxide layer and pollutants on the surface of the circuit board.

For this reason, the inventor of the present invention thought about an improved method, and designed several chemical deposition equipment for continuous production one by one for the chemical deposition tank used in the manufacturing process, and applied for and obtained patents respectively. Chemical deposition method and equipment for piece-by-piece continuous production” and Invention Certificate No. I689523 “Chemical deposition equipment and method for piece-by-piece continuous production in horizontal inclined mode”. This greatly reduces the amount of expensive chemicals used. But the inventor is not complacent because of this, because pre-processing and post-processing equipment must be used in this process, the inventor thinks that if the entire group of chemical nickel-gold process systems can be integrated into a single system, it will be possible to reduce multiple removal processes. The process of removing oxide layer and pollutants produces greater benefits.

The main purpose of the present invention is to provide a chemical nickel-gold process method and system that can reduce chemical treatment steps, mainly by reorganizing and integrating the original process equipment with the chemical deposition equipment previously designed in the present invention for continuous production piece by piece, resulting in An innovative chemical nickel-gold process method and system, which can simultaneously reduce the consumption of cleaning water and various chemicals, save consumption and reduce expenditure costs, and reduce multiple processes. The cost of handling also results in a significant reduction.

To achieve the aforementioned object, the present invention adopts the following technical solutions:

The present invention is a chemical nickel-gold process method that can reduce chemical treatment steps. The steps include carrying out the circuit boards one by one in a horizontal conveying manner: acid cleaning, water washing, micro-etching, water washing, sandblasting, ultrasonic cleaning, water washing, pre-processing Acid leaching, water washing, pre-soaking, activation, water washing, post-acid leaching, water washing, and then turning the circuit board into a vertical shape and adopting a piece-by-piece continuous movement method: chemical deposition of nickel, water washing, chemical deposition of gold, recycling water washing, and then turning over The circuit boards are carried out by horizontal conveying method one by one: washing, drying, drying and other operations.

Furthermore, the present invention is a chemical nickel-gold process system that can reduce chemical treatment steps. It is composed of an acid cleaning tank, a first washing tank, a micro-etching tank, a second washing tank, a sandblasting tank, and an ultrasonic cleaning tank arranged in series. , third washing tank, pre-acid leaching tank, fourth washing tank, pre-soaking tank, activation tank, fifth washing tank, post-acid leaching tank, sixth washing tank, chemical deposition nickel tank, seventh washing tank, chemical deposition Gold tank, recycling washing tank, eighth washing tank, drying tank, and drying tank.

As one of the preferred embodiments, the chemical deposition nickel tank and the chemical deposition gold tank use a piece-by-piece continuous production of chemical deposition equipment.

Compared with the prior art, the present invention has the following specific effects: 1. The design of the present invention can save operations and procedures such as brushing, water washing, micro-etching, water washing, pickling, water washing, blow-drying, drying and manual collection of circuit boards in the conventional pre-treatment, and relatively saves chemical The cost of liquid medicine, cleaning water, electricity, labor, chemical waste liquid and wastewater treatment. 2. The design of the present invention can also save the pickling, ultrasonic cleaning and other processes in the conventional post-treatment, and relatively save costs including chemical liquid, cleaning water, electricity, labor, chemical waste liquid and wastewater treatment. 3. The present invention integrates the original pre-processing equipment, chemical deposition equipment and post-processing equipment into a single system, which reduces the cost of a number of equipment, and because of the integration into a single system, the length of the equipment is shortened, making all The required factory area is reduced, and the space of the factory can be used more effectively. 4. Using the circuit board produced by the present invention, the surface gloss is relatively bright, but observed with a scanning electron microscope (SEM), the structure of the deposited gold layer is relatively rough,

The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments and accompanying drawings. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

First, a brief description of the terms used in the process: Acid cleaning is the use of organic or inorganic acids to remove slight oxides on the copper surface of the circuit board. Microetching (Micor-etching): It is a microetching solution to remove the oxide layer of the copper surface on the circuit board. Pickling (Acid dip): Soak in dilute sulfuric acid to remove oxides on the copper surface after microetching. Pre-dip (Pre-dip): Soak in the reaction solution to make the copper surface free of oxides. Activation: Replace a layer of palladium on the copper surface as a catalyst for chemical nickel reaction. Electroless nickel deposition: A nickel-containing alloy is plated on the copper surface as a barrier layer to prevent migration (Migration) or diffusion (Diffusion) between gold and copper. Electroless gold deposition: a gold layer is deposited on the nickel surface on the copper surface.

As shown in FIG. 2 , it is a flowchart of the chemical nickel-gold process that can reduce chemical treatment steps in the present invention. The steps include acid cleaning 301, water washing 302, micro-etching 303, water washing 304, sand blasting 305, ultrasonic cleaning 306, water washing 307, pre-acid leaching 308, water washing 309, pre-soaking 310, activation 311, water washing 312, post-acid leaching 313, water washing 314, chemical nickel deposition 315, water washing 316, chemical deposition gold 317, recycling water washing 318, water washing 319, drying 320, drying 321 and other operations.

The design of the present invention is to allow the initial circuit board to undergo a series of chemical nickel-gold process steps to complete the surface treatment of the circuit board through the above process. For this reason, the circuit board must be acid-cleaned 301, washed 302, micro-etched 305, washed 306, sand blasted 307, ultrasonic cleaned 308, washed 309, pre-acid leached 308, washed 309, pre-dipped 310, Activation 311, water washing 312, post-acid leaching 313, water washing 314 and other steps.

Next, the circuit board will be turned upside down and carried out in a continuous moving manner one by one: electroless nickel deposition 315 , water washing 316 , electroless gold deposition 317 , recycling water washing 318 and other steps.

Afterwards, the circuit board is turned over again to be horizontal and carried out by means of horizontal transportation: washing 319 , drying 320 , drying 321 and other steps.

As shown in Fig. 3 and Fig. 4, it is a side view and a top view of the chemical nickel-gold process system which can reduce the chemical treatment steps of the present invention. The system includes an acidic cleaning tank 401, a first washing tank 402, a micro-etching tank 403, a second washing tank 404, a sandblasting tank 405, an ultrasonic cleaning tank 406, a third washing tank 407, and a pre-acid leaching tank arranged in series and side by side. 408, fourth washing tank 409, prepreg tank 410, activation tank 411, fifth washing tank 412, post-acid leaching tank 413, sixth washing tank 414, chemical deposition nickel tank 415, seventh washing tank 416, chemical deposition gold Tank 417 , recovery washing tank 418 , eighth washing tank 419 , drying tank 420 , drying tank 421 . Each slot is equipped with a relevant conveying mechanism to deliver the circuit boards horizontally or vertically to each slot for processing. In addition, the washing tanks listed above are not limited to a single tank, depending on the cleaning needs, 1 to 5 tanks can be connected in series to achieve the required cleanliness.

Furthermore, the acid cleaning tank 401, the first washing tank 402, the micro-etching tank 403, the second washing tank 404, the sandblasting tank 405, the ultrasonic cleaning tank 406, the third washing tank 407, the front acid dipping tank 408, the fourth washing tank Tank 409, prepreg tank 410, activation tank 411, fifth washing tank 412, post-acid dipping tank 413, and sixth washing tank 414 are equipped with horizontal conveying mechanisms in the tanks, so that the circuit boards are horizontal and sequentially Chips enter the slots for related cleaning, activation of the circuit board surface and other procedures. Afterwards, the circuit board is flipped from horizontal to vertical and moved one by one in each slot to carry out operations such as deposition and cleaning. Among them, the chemical deposition nickel tank 415 and the chemical deposition gold tank 417 can adopt the chemical deposition equipment designed by the inventor for continuous production one by one. Afterwards, the circuit board is turned over into a horizontal shape, and the eighth washing tank 419, the drying tank 420, and the horizontal conveying mechanism provided in the drying tank 421 are horizontally washed, dried, and dried in sequence.

Using the process flow of the present invention, the surface gloss of the circuit board produced is relatively bright, but the structure of the deposited gold layer is relatively rough when observed by a scanning electron microscope (SEM), but this will not affect the quality of subsequent processing. Yield rate, manufacturers can choose a suitable process according to their own needs.

From the above description, it can be known that using the chemical nickel-gold process of the present invention does not need to separate several different processes and carry out in different equipments. A single circuit board is fed into the system of the present invention. According to the process steps of the present invention, the surface treatment of the circuit board can be completed by using the chemical nickel-gold process. Grinding, water washing, micro-etching, water washing, pickling, water washing, drying, drying and post-processing pickling, ultrasonic cleaning, etc., greatly reduce the use of chemical medicine and cleaning water, allowing manufacturers to reduce production costs, The cost includes the cost of chemical potion, cleaning water, electricity, labor, chemical waste liquid and wastewater treatment, etc., so that the production of products with more market competitiveness meets the requirements for patent application.

The above are only preferred embodiments of the present invention, and are not intended to limit the scope of the embodiments of the present invention. That is, all equivalent changes and modifications made according to the patent scope of the present invention are covered by the patent scope of the present invention.

101: Brush grinding groove 102: washing tank 103: Sand blasting tank 104: washing tank 105: Ultrasonic cleaning tank 106: micro-etching groove 107: washing tank 108: pickling tank 109: washing tank 110: Blow drying tank 111: drying tank 121: cleaning tank 122: washing tank 123: micro-etching groove 124: washing tank 125: Front pickling tank 126: washing tank 127: Prepreg tank 128: activation tank 129: washing tank 130: exchange position slot 131: post-acid leaching tank 132: washing tank 133: Electroless nickel deposition bath 134: washing tank 135: Chemical deposition gold tank 136: washing tank 137: drying tank 141: pickling tank 142: washing tank 143: Ultrasonic cleaning tank 144: washing tank 145: Blow drying tank 146: drying tank 200: hanging basket 201: The first crane moves the crane 202: The second crane moves the crane 301: acid cleaning 302: washed 303: Microetching 304: washed 305: sandblasting 306: Ultrasonic cleaning 307: washed 308: Pre-pickling 309: washed 310: Prepreg 311: activation 312: washed 313: post acid leaching 314: washed 315: Electroless nickel deposition 316: washed 317: Chemically deposited gold 318: Recycled washing 319: washed 320: blow dry 321: drying 401: acid cleaning tank 402: The first washing tank 403: micro-etching groove 404: Second washing tank 405: sandblasting 406: Ultrasonic cleaning 407: The third washing tank 408: Front pickling tank 409: The fourth washing tank 410: prepreg tank 411: activation tank 412: Fifth washing tank 413: post-acid leaching tank 414: The sixth washing tank 415: Electroless nickel deposition bath 416: The seventh washing tank 417: Chemical deposition gold bath 418: Recycling washing tank 419: Eighth washing tank 420: Blow drying tank 421: drying tank

FIG. 1A is a side view of the pre-processing equipment used in the conventional chemical nickel-gold process.

FIG. 1B is a side view of an electroless deposition equipment used in a conventional electroless Ni-Au process.

FIG. 1C is a side view of the post-processing equipment used in the conventional electroless Ni-Au process.

FIG. 2 is a flow chart of the chemical nickel-gold process that can reduce chemical treatment steps in the present invention.

FIG. 3 is a side view of the chemical nickel-gold process system capable of reducing chemical processing steps according to the present invention.

FIG. 4 is a top view of an electroless nickel-gold process system capable of reducing chemical processing steps according to the present invention.

301: acid cleaning

302: washed

303: Microetching

304: washed

305: sandblasting

306: Ultrasonic cleaning

307: washed

308: Pre-pickling

309: washed

310: Prepreg

311: activation

312: washed

313: post acid leaching

314: washed

315: Electroless nickel deposition

316: washed

317: Chemically deposited gold

318: Recycled washing

319: washed

320: blow dry

321: drying

Claims (3)

A chemical nickel-gold process method that can reduce chemical treatment steps. The steps include: sequentially carrying out circuit boards one by one by means of horizontal conveyance: acid cleaning, water washing, micro-etching, water washing, sandblasting, ultrasonic cleaning, water washing, and pre-acid cleaning. Dipping, water washing, pre-soaking, activation, water washing, post-acid leaching, water washing, and then turning the circuit board into a vertical shape and adopting a piece-by-piece continuous movement method: chemical deposition of nickel, water washing, chemical deposition of gold, recovery of water washing, and then turning over The circuit board is carried out by horizontal conveying method one by one: washing, drying, drying and other operations. A chemical nickel-gold process system that can reduce chemical treatment steps is composed of an acid cleaning tank, a first washing tank, a micro-etching tank, a second washing tank, a sandblasting tank, an ultrasonic cleaning tank, a third washing tank, Pre-acid leaching tank, fourth washing tank, pre-soaking tank, activation tank, fifth washing tank, post-acid leaching tank, sixth washing tank, chemical deposition nickel tank, seventh washing tank, chemical deposition gold tank, recovery washing tank , The eighth washing tank, drying tank, drying tank constituted. In the chemical nickel-gold process system capable of reducing chemical treatment steps as described in claim 2, the chemical deposition nickel tank and the chemical deposition gold tank use a piece-by-piece continuous production of chemical deposition equipment.

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