外文翻譯---水平處理技術(shù)創(chuàng)新

1、1An innovation in horizontal processingPeter Lymn and Ken BishopCEMCO FSL Ltd, Waterlooville, UKAbstractPurpose – The purpose of this paper is to detail an innovative new equipment enhancement for use in the horizontal

2、processing of printed circuit boards (PCBs).Design/methodology/approach – The paper describes a non-contact laminar or streamline flow process chamber. It also describes a transport and guiding method suitable for both

3、thick and thin materials and expands on the mechanics and fluid dynamics that further reduce equipment length and operating cost. Findings – The new process chamber and its related enhancements result in a faster and mor

4、e uniform chemical reaction than is obtainable with conventional flood chambers. This enables the equipment to have reduced length and to offer reduced operating costs.Originality/value – The paper presents a new approa

5、ch to horizontal processing that can offer reduced equipment footprints and reductions in operating costs. Keywords Process management, Printed circuits, Conveyors, Chemical technology processIntroductionPrinted circuit

6、board (PCB) fabricators have used horizontal roller conveyers to transport copper clad laminate through chemical spray treatment chambers for many years. These simple conveyorised spray processors have evolved over time

7、 to accommodate much thinner materials, but the complication of guiding and supporting them through spray jets generally means two types of machine are required; one for thick, rigid material and another longer, more c

8、omplex system for very thin or flexible substrates. More recently, this type of equipment has been further adapted to incorporate immersion chambers for plating and other surface treatment processes where spray jets are

9、 not suitable. The need to contain the static head above the roller transport system and the relatively long contact times required for immersion processes make these systems even longer and more complex. This paper de

10、scribes a non- contact laminar or streamline flow process chamber that results in a faster and more uniform chemical reaction than is obtainable with conventional flood chambers. It also describes a transport and guidin

11、g method suitable for both thick and thin materials and expands on the mechanics and fluid dynamics that further reduce equipment length and operating cost.3Some chemical processes associated with the printed circuit in

12、dustry require a gas (normally oxygen in the form of air) to be introduced at the point of contact of the chemical with the panel being processed. A dual fluid version of the “Streamline Fluid Engine” that simultaneous

13、ly feeds gas and liquid to the discharge slots provides this facility, while maintaining the characteristics associated with the standard “Fluid Engine”. The design of this engine is shown in Figure 2.The gas is fed und

14、er pressure to the outer gas plenum (shown in green) that is separated from the liquid plenum by a permeable membrane. The base plate has a series of closely spaced holes that normally connect the base plate directly to

15、 the liquid plenum across the width. In the dual feed head the liquid plenum has a series of tubes that connect the gas plenum to the base plate. These tubes are pitched such that they line up with every other hole in

16、the base plate and seal the holes from the liquid in the plenum. Therefore, gas and liquid are delivered side by side across the width of the panel through alternate holes. Figure 2 shows how both gas and chemical reach

17、the output jets. The lower head shows the path that the gas takes to reach the jets and the upper head shows how the chemical does. Gas is shown as green and chemical as blue.Figure 2 Dual fluid engine to introduce a g

18、as into the chemical streamFluid knifeWhere it is necessary to remove chemicals from the panel by dilution, or where high fluid impingement is required to wet blind features, a shorter version of the fluid engine, known

19、 as a fluid knife, is used. Typically, this fluid knife is used for water rinsing after a chemical process or pre-treating prior to a chemical process (Figure 3). The fluid knife considerably reduces both the conveyor

20、length and the power required to pump solution onto the panel. For example, a single fluid knife provides a solution rate of 40L per minute using a 110W pump, compared to a more conventional spray rinse that delivers 2

21、8L per minute from a 750W pump. Similarly, the fluid knife requires only 170mm of conveyor length compared to 240mm for the spray rinse. As with the fluid engine, thin material transport is assisted by the fluid flow c