Placement system

High-performance placement systems ace available for the highest placement rates, especitilly for telecommunications products. These systems ttike advantage of several individual parallel pick-and-place systems. A placement rate of up to 140,000 components per hour can be attained. 

Conventional printing processes are less useful for applying conductive adhesives or solder paste. Dispensing of single dots in a complex geometric application is therefore necessary. Three-dimensional circuit carriers also decrease the freedom of component placement, which leads to restrictions for placement systems. 

One way for SMD assembly onto MID is to use six-axis robots, which arc designed as geometry-flexible handling systems for reaching each point in the workspace with every possible orientation of the tool. The available placement systems for SMD assembly onto PCBs are optimized for placement accuracy and speed. In order to work with these systems on MIDs, it is important to be able to move them during the process (Feldmann and Krimi 1998). 

The first step was a systematic development of a MID placement system outgoing from an available four-axis system. This aim is realized by extending the machine by two DOF. First, an additional movement in the direction of z-axis allows high obstacles to be surmounted. Second, the MID can be inclined so that the process plane is oriented horizontally in the workspace. This concept is not suitable for MIDs with high geometrical complexity. 

Robot placement systems have till now been used primarily to place exotic THT components such as coils and plugs, whose assembly is not possible with pick-and-place machines. The application of... 

This geometric advantage and the flexibility of the robot system come at the expense of lower productivity and accuracy than with Cartesian systems. Therefore, Cartesian placement systems should be the basis for a specialized MID assembly system. 

For both these concepts to be realized, it is necessary to extend and work on hardware and control software of the PCB basic assembly system. These systems are realized with a widespread standard system at the FAPS Institute. Figure 45 shows the developed MID placement system with the different modules for the handling of SMD components and MID. 

The way to enlarge the system kinematics of standard placement systems is to move the workpiece during the assembly process. Solutions for this problem are as follows. 

Eigure 44 Flexible Robot Placement System for Assembly onto MID. 

Eigure 45 Prototypical Realization of MID Placement System for 3D assembly. (From Feldmann et al. 1998)... 

Feldmann, K., and Krimi, S. (1998), Alternative Placement Systems for Three-Dimensional Circuit Board, Anna/i of the CIRP, Vol. 47, No. 1, pp. 23-26. 

Carrying allowances, 1396 Carrying costs, 2021 Cartesian placement systems, 436, 438 Cartesian robots, 374, 375 Carton, 2087... 

PI (proportional-integral) control models, 160 Placement systems electronic components, 425-429 3D PCBs, 435-438... 

D printed circuit boards (3D PCBs) placement systems for, 423 soldering, 438-439... 

Students bac score helps to determine their placement in nniversity. Those who score high enough can pass into the first phase of an engineering diploma, which is 2 years of intense theoretical instraction. Everyone who passes the bac is guaranteed a placement in tertiary schoohng, though, as some academic respondents note, sometimes with this placement system, students do not even get one of their top ten choices. At the end of this 2-year phase, another exam determines where they... 

Figure 21.80 Processing head for Viper 3000 7-axis fiber placement system. Source Courtesy Cincinnati Machine.

Raytheon Aircraft have designed the Premier I cabin around a sandwich of inner and outer carbon fiber layers around a layer of honeycomb material. The carbon fiber/epoxy tows were applied by a Cincinnati Machine Viper 7-axis fiber placement system, producing a structure 20% lighter than an A1 one (Figure 23.19). 

Fig. 31. Seven axes of motion on fiber-placement system can steer prepreg tow or slit tape around compound-curvature shapes to make highly contoured parts. Courtesy of Cincinnati Machine.

Fig. 32. CNC Viper fiber-placement system lays individual tows on a mandrel, shown here making a helicopter rotor blade spar at Bell Helicopter Textron (Fort Worth, Tex.). Courtesy of Cincinnati Machine and Bell Helicopter.

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