TWI780761B - Detergent composition and cleaning method of printed circuit board - Google Patents

Abstract

The invention provides a cleaning agent composition and a cleaning method for printed circuit boards. One of the detergent compositions includes: 10 wt% trisodium phosphate, 5 wt% sodium methanesulfonate, 20 wt% potassium carbonate, 10 wt% surfactant and 55 wt% water. Another detergent composition includes: 10wt% benzotriazole, 5wt% citric acid, 10wt% sulfuric acid, 5wt% copper sulfate, 20wt% methanol and 50wt% water.

Description

Detergent composition and method for cleaning printed circuit boards

The invention relates to a cleaning agent composition and a cleaning method for electronic parts, in particular to a cleaning agent composition and a cleaning method for printed circuit boards.

In the manufacturing process of printed circuit boards, the pollutants on the copper surface, such as impurities, impurities or adhesive deposits caused during production, are mostly removed by acid-base etching or alkali saponification. However, the above-mentioned methods cannot remove the more tenacious large-area adhesive deposits.

For example, after the solder mask printing step, if the contamination left on the copper surface is not removed, it will affect the subsequent gold plating step. Here, the so-called "gold" step is a surface treatment method that allows nickel and gold to adhere to the copper surface without using electroplating. It is generally called Electroless Nickel Immersion Gold (ENIG) . Simply put, ENIG uses chemical replacement to create the effect of a gold layer on the surface. However, before the gold plating step, if there are still pollutants on the copper surface, the normal adhesion of nickel and gold on the copper surface will be caused.

Therefore, before carrying out the gold chemical step, it is necessary to remove the pollutants on the copper surface.

In view of this, the object of the present invention is to provide a cleaning agent composition capable of removing pollutants on the copper surface of a printed circuit board, and a method of using the composition.

In order to achieve the above-mentioned purposes and effects, the first embodiment of the present invention provides a cleaning agent composition for removing the residual glue on the copper surface of the finished or semi-finished printed circuit board. The cleaning agent composition includes the following ingredients (1) 5~15wt% trisodium phosphate; (2) 1~9wt% sodium methanesulfonate; (3) 15~25wt% potassium carbonate; (4) 5~15wt% surfactant; And (5) water with a total of 100wt% of the above ingredients.

In the second embodiment of the present invention, the percentages by weight of the aforementioned ingredients are: (1) 10wt% trisodium phosphate; (2) 5wt% sodium methanesulfonate; (3) 20wt% potassium carbonate; 4) 10 wt% surfactant; and (5) 55 wt% water.

In addition, the third embodiment of the present invention provides a cleaning agent composition for removing oxides on the copper surface of finished or semi-finished printed circuit boards. The cleaning agent composition includes the following ingredients: (1) 5~15wt% of Benzotriazole; (2) 1~9wt% citric acid: (3) 5~15wt% sulfuric acid: (4) 1~9wt% copper sulfate; (5) 15-25wt% methanol; and (6) 100wt% water combined with the above ingredients.

In the fourth embodiment of the present invention, the weight percentages of the aforementioned ingredients are: (1) 10wt% benzotriazole; (2) 5wt% citric acid; (3) 10wt% sulfuric acid; (4) 5 wt% copper sulfate; (5) 20 wt% methanol; and (6) 50 wt% water.

In addition, the fifth aspect of the present invention provides a method for cleaning a printed circuit board, comprising: a) soaking the printed circuit board in the cleaning composition of the first and second embodiments of the present invention; b) using The step of washing the printed circuit board with water by spraying or soaking; c) the step of soaking the printed circuit board in the cleaning agent composition according to the third and fourth embodiments of the present invention; d) washing the printed circuit board by spraying or soaking The step of washing the printed circuit board with water; e) the step of washing the printed circuit board with ultrasonic water; and f) the step of drying the printed circuit board.

In the sixth aspect of the present invention, wherein, in the step a), the soaking temperature is 60-80° C., and the soaking time is 5-10 minutes.

In the seventh aspect of the present invention, wherein, in the step c), the soaking temperature is room temperature, and the soaking time is between 15 and 30 seconds.

In the eighth aspect of the present invention, wherein, in the step b), the step d) or the step e), the washing temperature is room temperature and the washing time is 30 seconds.

In order to facilitate your review committee to further understand and understand the purpose, shape, structure, device features and effects of the present invention, the embodiments are described in detail as follows:

First of all, it should be explained that the cleaning agent composition disclosed in the embodiments of the present invention is mainly used for cleaning the copper surface in the process of printing circuit boards. In the following embodiments, different detergent compositions and methods for cleaning printed circuit boards using these detergent compositions will be described.

The cleaning agent composition disclosed in the embodiments of the present invention can be used to clean the copper surface after the printing process of the printed circuit board; it can also be used to clean the copper surface before the surface treatment process such as electroplating or chemical plating after the printing process; It is even possible to clean the copper surface of the printed circuit board after molding.

Hereinafter, embodiments of the present invention will be described sequentially.

As shown in Table 1, an embodiment of the present invention discloses a cleaning agent composition for the copper surface of a printed circuit board, which is mainly used for cleaning the copper surface after the solder mask printing step and before the gold plating step. Here, the cleaning agent composition in Table 1 can also be referred to as a copper surface optimizer, and its purpose is to remove glue-like substances on the copper surface. These glue-like substances on the copper surface are mostly the glue left on the copper surface after the solder resist printing step. Leak money. Therefore, as shown in Table 1, one embodiment of the present invention discloses a cleaning agent composition, which can Effectively remove the glue-like substances remaining on the copper surface of the printed circuit board after the solder mask printing step. Preferably, the detergent composition includes: 10wt% trisodium phosphate, 5wt% sodium methanesulfonate, 20wt% potassium carbonate, 10wt% surfactant and 55wt% water. In other embodiments, the detergent composition comprises the following ingredients: 5-15wt% trisodium phosphate, 1-9wt% sodium methanesulfonate, 15-25wt% potassium carbonate, 5-15wt% surface active agent; and 100wt% water in total with the above ingredients.

Next, another detergent composition of the present invention will be described.

As shown in Table 2, another embodiment of the present invention discloses a cleaning agent composition for the copper surface of a printed circuit board, which is mainly used for cleaning the copper surface after the solder mask printing step and before the gold plating step. Here, the cleaning agent composition in Table 2 can also be referred to as a copper surface accelerator, and its main purpose is to remove oxides on the copper surface. It can be seen from Table 2 that the sulfuric acid component can remove copper oxide. Preferably, the detergent composition includes: 10wt% benzotriazole, 5wt% citric acid, 10wt% sulfuric acid, 5wt% copper sulfate, 20wt% methanol and 50wt% water. In other embodiments, the detergent composition comprises the following ingredients: 5-15wt% benzotriazole, 1-9wt% citric acid, 5-15wt% sulfuric acid, 1-9wt% copper sulfate, 15~25wt% methanol; and 100wt% water in total with the above ingredients.

Hereinafter, an example of the present invention is used to illustrate the usage method of the cleaning agent composition (copper surface optimizer) in Table 1 and the cleaning agent composition (copper surface accelerator) in Table 2 of the present invention. In this embodiment, the printed circuit board is cleaned before the gold plating step after the solder mask printing step of the printed circuit board.

The method for cleaning a printed circuit board provided by an embodiment of the present invention includes: a) soaking the printed circuit board in the cleaning agent composition as shown in Table 1; b) washing the printed circuit board with water by spraying or soaking c) the step of immersing the printed circuit board in the cleaning agent composition as shown in Table 2; d) the step of washing the printed circuit board with water by spraying or soaking; e) the step of carrying out the ultrasonic water washing of the printed circuit board steps; and f) the step of drying the printed circuit board.

First, in step a), the printed circuit board is soaked in the cleaning agent composition as shown in Table 1, and the temperature of the cleaning agent composition in Table 1 is between 60-80° C., and the soaking time is between 5-10 minutes. Since the detergent composition in Table 1 can quickly penetrate into the tenacious attachments, the attachments are rapidly disintegrated and combined with water, and then diffused and dissolved in water. Therefore, this step can effectively remove a large area of residual glue on the copper surface of the printed circuit board.

Then, in step b), for the printed circuit board immersed in the cleaning agent composition in Table 1, the printed circuit board is washed with water by spraying or soaking, and the cleaning agent composition in Table 1 and the copper on the printed circuit board are washed away. Adhesive residue and other contaminants on the surface. In this step, the water temperature for spraying or soaking is room temperature, and the cleaning time is 30 seconds.

Then, in step c), the printed circuit board is soaked in the cleaning agent composition as shown in Table 2, wherein the temperature of the cleaning agent composition in Table 2 is room temperature, and the soaking time is between 15-30 seconds. Through this step, oxides such as copper oxide on the copper surface of the printed circuit board can be effectively removed. After testing, after soaking for 30 seconds, the amount of copper corrosion is less than or equal to 20 micro-inches (micro-inch), and the copper surface has a polished surface without oxidation and damage to the green paint.

Then, in step d), for the printed circuit board soaked in the cleaning agent composition in Table 2, the printed circuit board is also washed with water by spraying or soaking, and the cleaning agent composition in Table 2 and the printed circuit board are washed away. Oxides such as copper oxide and other contaminants on copper surfaces. In this step, the water temperature for spraying or soaking is room temperature, and the cleaning time is 30 seconds.

Afterwards, in step e), the printed circuit board is further subjected to ultrasonic water washing, so as to completely clean the copper surface of the printed circuit board.

Finally, in step f), the cleaned printed circuit board is subjected to a subsequent drying step.

Below, Table 3 is used to illustrate the effectiveness of the printed circuit board cleaning method of the above-mentioned embodiment of the present invention. First, the terminology in Table 3 is explained. The so-called "copper excellence" refers to the optimization of the copper surface, as mentioned above, by means of cleaning and polishing, so that the copper surface can be used for the subsequent gold plating process. "Small quantities" and "batches" refer to the number of printed circuit boards tested.

As can be seen from Table 3, after the cleaning method of the printed circuit board provided by the above-mentioned embodiment of the present invention, all kinds of residual glue, oxidized foreign matter, or other foreign matter are effectively removed. Therefore, after cleaning with the cleaning agent composition in Table 1 and the cleaning agent composition in Table 2, the printed circuit board reaches the level where subsequent gold plating process can be performed. Of course, in other embodiments, the above-mentioned method for cleaning the printed circuit board may also be used to clean the copper surface after different process stages or to clean the copper surface after the printed circuit board is formed.

[table 3]

The above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced. Without departing from the spirit and scope of the technical solution of the present invention.

Claims (6)

A cleaning agent composition for removing residual glue on the copper surface of finished or semi-finished printed circuit boards. The cleaning agent composition includes the following ingredients: (1) 5~15wt% trisodium phosphate; (2) 1~9wt% % of sodium methanesulfonate; (3) 15~25wt% of potassium carbonate; (4) 5~15wt% of surfactant; and (5) water with the total of 100wt% of the above ingredients. The cleaning agent composition as described in claim 1, wherein the weight percentages of these ingredients are respectively: (1) 10wt% trisodium phosphate; (2) 5wt% sodium methanesulfonate; (3) 20wt% Potassium carbonate; (4) 10 wt% surfactant; and (5) 55 wt% water. A method for cleaning a printed circuit board, comprising: a) a step of soaking the printed circuit board in the detergent composition according to claim 1 or 2; b) a step of washing the printed circuit board with water by spraying or soaking c) a step of soaking the printed circuit board in another detergent composition; d) a step of washing the printed circuit board with water by spraying or soaking; e) a step of washing the printed circuit board with ultrasonic water and f) the step of drying the printed circuit board; Wherein, the other cleaning agent composition is used to remove oxides on the copper surface of the finished or semi-finished printed circuit board, and the other cleaning agent composition includes the following ingredients: (1) 5~15wt% benzotriazole (2) the citric acid of 1～9wt%; (3) the sulfuric acid of 5～15wt%; (4) the copper sulfate of 1～9wt%; (5) the methanol of 15～25wt%; Total is 100 wt% water. The method for cleaning a printed circuit board as described in Claim 3, wherein, in the step a), the soaking temperature is between 60°C and 80°C, and the soaking time is between 5 and 10 minutes. The cleaning method for printed circuit boards as described in Claim 3, wherein, in the step c), the soaking temperature is room temperature, and the soaking time is between 15 and 30 seconds. The cleaning method for printed circuit boards as described in claim 3, wherein, in the step b), the step d) or the step e), the washing temperature is room temperature, and the washing time is 30 seconds.