As considered by the users, the most basic requirement for choosing and buying PCB brushing machine is to buy one machine of good operationality. Then, what kind of PCB brushing machine has good operationality?

To buy a PCB brushing machine of good operationality, firstly, you shall determine what process step the machine will be used in and the specific requirements of this process step. Only the brushing machine suitable for the ampere process step is the brushing machine of good operationality!

Based on the grinding stability to which the users always pay most attention, we have categorized the brushing machines into three categories: heavy-grinding brushing machine, moderate-grinding brushing machine, and light-grinding brushing machine. What data may be used to define the three categories of brushing machines? That is to say, how can we distinguish the three categories of brushing machines? We, based on the long-term experience accumulated in the PCB industry, recommend you to make judgment from the following two aspects:

 1. Operation stability

In general, we have defined the PCB brushing machines that can work stably at a grinding ampere between 1.5 A and 2.5 A for a long time (over 4 hrs) as the heavy-grinding brushing machine (noise level: ≤75 DB). The brushing machines of this category can keep stable operation at such high grinding ampere, showing no obvious vibration! The representative products of the heavy-grinding brushing machines are the ISHIIYOKI Deburring Type Brushing Machine ( Japan ), Seiko SDT type Brushing Machine ( Japan ), and Marugen Heavy-grinding Brushing Machine ( Japan ). The brush roller driving motors of such brushing machines have a rated ampere of 2.2KW. (Note: The dry-run ampere of the machine when the brush doesn't contact the board is called as the no-load ampere; the ampere rise over the no-load ampere after the brush contacts the board is called as the grinding ampere.)

We have defined the PCB brushing machines that can work stably at a grinding ampere between 1.0 A and 1.5 A for a long time as the moderate-grinding brushing machine (noise level: ≤75 DB). The representative products of the moderate-grinding brushing machines are the Seiko SD type Brushing Machine ( Japan ), Songtex/Sunny Brushing Machine ( Taiwan ), and SCHMID Brushing Machine etc (German) and etc. The brushing machines of this category generally adopt the brush roller driving motors with a rated ampere of 1.5KW.

We have defined the brushing machines that can work stably at a grinding ampere lower than 1.0 A for a long time as the light-grinding brushing machine (noise level: ≤75 DB). The price level of the brushing machines of this category is the most economical. They adopt the brush roller driving motors with a rated ampere lower than 1.5 KW. However, the customers of brushing machines of this category shall understand the following: once you have bought the brushing machine of this category, you shall know which process step it will be applied in, otherwise you will often get in trouble!

 2. Structure of brushing machine

According to our experience, generally, the steel plate of the main structure of one heavy-grinding brushing machine shall have a thickness more than 15mm ; that of one moderate-grinding brushing machine shall be more than 8mm ; and that of one light-grinding machine may be less than 5mm .

Certainly, to test correctly any brushing machine to judge which category it belongs to, it's necessary to choose and use correct grinding brush rollers. If you want to use the brush rollers of low cut-force to test one heavy-grinding brushing machine, the test will be very difficult, or the test result will be incorrect. Therefore, it's recommended that the users shall use the labeled GSH high-cut, moderate-cut and low-cut brush rollers to test the brushing machines of the corresponding grades respectively. It's believed that the users will see the accuracy and reliability of such tests in future long-term operation.

As a whole, the successful purchase of the correct brushing machine doesn't mean all is ok, because good grinding performance relies on the combination of the good brushing machine and good grinding brush roller. That is to say, without choosing good grinding brush rollers, the brushing machine won't be highly operational for this process step. About the selection of grinding brush roller, please see the related information in the Goal Searchers Forum at www.goalsearchers.com , and the related information in the Grinding Brush Rollers for PCB Manufacturing . According to the general principle, the high-cut brush rollers must be matched with the heavy-grinding brushing machines; the moderate-cut brush rollers shall be matched with the moderate-grinding brushing machines at least or the heavy-grinding brushing machines but the light-grinding brushing machines.

The combination of the GSH high-cut brush roller and heavy--grinding brushing machine shall be able to support “t ≥0.1um” (t: thickness of CCL copper sheet cut once every brush); the combination of the GSH ceramic brush roller and heavy-grinding brushing machines shall be able to support “t ≥1.0μm”; and the combination of the GSH moderate-cut brush roller and moderate-grinding brushing machines shall be able to support “t ≥0.01um”.

Each process step of PCB manufacturing has its own requirements on brushing machine, which are very differently for those of other process steps. For example, the deburring step requires moderate-grinding brushing machine at least depending on the quality of the holes drilled. If the holes have large debuurs (e.g., ≥75um ） , it's even necessary to use heavy-grinding machine. In such case, the brushing machines of good operationality are those that can remove burs completely, which may be evaluated by the appearance and slice analysis method. To remove hole-plugging ink or resins overflowed or PP glue points occurred during resin/copper surface flattening or steel plate pressing, it's necessary to use heavy-grinding machine. In such case, the standard for high operationality is that the burs have been removed completely and the surface has been flattened (by visual check). The preprocessing of dry film resist needs grinding brushing machine. In such case, the standard of good operationality is as follows: ① water break time: ≥15s; ②Roughness (Rz): 1.5 - 3.0um; and ③ Uniform appearance. The processing before soldering protection (green oil spreading) and the board surface washing need light-grinding brushing machine. In such case, the standard of good operationality is as follows: ① water break time: ≥15s; ②Roughness (Rz): 1.5 - 2.5um; and ③ Uniform appearance.

Goal Searchers Co., Ltd, Zhuhai (GSH), one manufacturer specialized in producing grinding brush rollers, can provide really high-cut/moderate-cut/low-cut brush rollers. We sincerely hope that we can share the above experience with the friends in concern with such subject to ensure we can provide better and better grinding solutions for PCB manufacturing process in a faster and faster manner! Any comments and suggestions from the friends in concern with such subject are welcome!