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Optical alignment BGA rework station
Optical alignment BGA rework station
Installation is in optical alignment system, high performance BGA rework station by optical system
industrial CCD, positioning in the whole course through the monitor to observe. Precision linear
guide rail mounting head makes accurate moving object stage, can achieve X, Y direction and angle
can be adjusted. Precise positioning of BGA. CCD is an important part of the optical system design,
which directly determines the resolution of the image acquisition, image quality, and is closely
related to the operation mode of the device. The main function of CCD is to change the sensitive
signal into an ordered electrical signal, so that the software system can be analyzed and processed
by image processing. In addition, the lens is an auxiliary optical accessory of CCD imaging, which is
adjusted to achieve the desired focal length and clarity of the camera. A good CCD is able to capture
the quality of the image, it has to mention a pixel, the more often it is considered that the higher the
pixel of its detection results are better, more accurate. In fact, we need to understand the camera pixels,
the camera's resolution and shooting range, to choose the best.
Precision mechanical system precision mechanical system is the main structure of BGA rework station,
to the device provides stable foundation, premise to realize the high accuracy, high efficiency and high
stability. BGA rework station in the repair process in motion speed is very strict, under different speed is
fast, slow and accuracy and stability requirements is very high. Therefore, in the design of precision
mechanical systems, more attention should be paid to the structural stability and the positioning
accuracy of the machine, and the repeatability of the positioning accuracy. Precision machinery system
of security protection measures strength will also affect the accuracy of repair, in the usual case with the
high resolution grating ruler as a system to achieve closed-loop control of position detection device,
BGA rework station positioning accuracy and repeatability can be improved by controlling system.
BGA rework commonly used several kinds of main structure, there are three (have a common characteristic
is: the upper part of the heating head either manually or automatically, but the Z axis can move). A, fixed
upper part, the work table manual movement; loading and unloading workpiece is very convenient, simple
operation, but the requirements of the requirements of the moving block is smooth, moving process will
cause a lot of motion error. Only suitable for accuracy is not high or high chip package rework; B, and the
upper part of the worktable can also manually move; loading and unloading work convenient, good
operation performance, but repair each product operation complex takes a long time to Para Para steadily.
This structure is suitable for high precision, low frequency chip package rework. C, high speed automatic
moving; the X axis, Y axis and Z axis direction is along a guiding rail or mobile module, the speed can be
adjusted according to the different chip package, assembly difficulty is high; this structure is suitable for
high accuracy, high repeatability and large quantities of repair. After determining the main structure, but
also need to consider main structure design from the material properties, mainly for different chip packaging
materials in three aspects of temperature characteristics, motion characteristics and process characteristics of
analysis (temperature characteristics of materials in the main analysis material thermal expansion rate, therma
l conductivity, thermal expansion effect of thermal conductivity coefficient and the ratio of three parameters,
motion characteristics mainly consider the influence of density and elastic modulus of materials, process
characteristics need consider the characteristics of material processing.) Proposed according to different
precision, use environment, repair effect requirements of BGA rework station structure selects suitable materials,
to ensure that the design is reasonable.
The optical system is equivalent to BGA rework station "eyes", is to achieve high precision, high efficiency on
guarantee. The optical system of BGA rework station includes a camera mechanism, lighting mechanism and
related installation and adjustment mechanism. The lighting mechanism mainly involves the choice of light
source and the design of light source. The choice of light source should be considered, such as the type, quality,
power, power, voltage, life and stability of the light source, so that it is necessary to select the appropriate light
source with the combination of the specific application. There are several technical indicators is the choice of
light source must be taken into account, respectively, color temperature, color rendering index and illumination.
In the observation environment should not be subject to other light or color interference. A light source is
required to ensure that the light source is projected onto the measured area of the measured object.