Técnicas de montaje BGA
Publicado el 29-06-2020Las pautas de inspección BGA se determinan en base a las pautas para el montaje de los circuitos impresos terminados en IPC-A-610, así como otros criterios que se han definido entre el usuario y el instalador. En la práctica, estos criterios de inspección se cumplen en la práctica con una variedad de técnicas de inspección BGA. Estas técnicas incluyen la inspección visual y la inspección por rayos X.
There are a variety of techniques that make up optical inspection techniques for BGA inspection. These techniques include endoscopy and visual inspection. Endoscopy uses an optical gradient prism to align the transverse viewing area with the plane of the plate. This allows the inspector to see “below” the BGA package. This ad may be within a few lines of the page.
Endoscopy and visual inspection
This observation allows the inspector to see how the ball gets wet on both the PCB pads and the device pads. The corners are also a good indicator of whether a good reflow profile has been created. The inspector looks for a uniformly collapsed ball without stretching or “wasting” the spreading sweat fillet. Furthermore, the shape of the solder ball is seen in relation to the uniformity in the outer row of the solder balls. Furthermore, the surface of the ball is inspected with this instrument.
All signs of flaking, depressions, excess flow residue, and the like are visible and are part of the inspection route. A visual microscope is often used in visual inspection, in which the printed circuit board is tilted at an angle so that the same type of evaluation can be seen as the endoscope. There are often components along the way that limit the usefulness of this special technique.
BGA X-ray inspection
BGA X-ray inspection is the second category of BGA assembly inspection. X-ray inspection can be performed using an automatic X-ray inspection, which essentially takes an image when the dash is scanned, and then compares those images to the acceptable image library for a call or manual inspection, meaning that the operator must “drive” the device being tested under the x-ray source.
There are many different conditions that the X-ray system tries to recognize as part of BGA X-ray images for inspection. As part of the IPC-A-610 BGA inspection criteria, the BA must be aligned with other components and other grounded parts of the circuit board assembly. This is to ensure that minimum electrical clearances are not violated. Similarly, the distance between the solder balls must be confirmed using the same criteria. Also, the BGA X-ray test should confirm that there are no solder bridges or connections to unusual areas of the device. It is also used to determine voids in reflux joints to ensure that they are not more than 30% or less of the inspectable area of the part.
In addition to these IPC criteria that radiography should use as part of accepting/rejecting calls, there are other uses of radiography during BGA inspection. The x-ray image also determines the sphericity of the “roundness” of the solder balls when viewed from the z-axis plane. Also, the actual size of the solder balls can be measured and compared as a pass/fail criterion for BGA inspection.
BGA assembly
An electronic assembly service is a company that deals with the manufacture of electronic assemblies, such as the spherical grid die or BGA. Why do manufacturers have to outsource these services?
The biggest advantage of outsourcing assemblies is that they save a lot of resources. You don’t have to build or lease additional assembly space, and you don’t need assembly personnel. The installation of a production plant, the purchase of appropriate equipment, and the use of well-trained and experienced personnel to manage the plant require a lot of capital. The fact that you can focus on the core function of your business means that you are more productive. This also saves time.
With good electronic assembly services, your assembly is contracted. This means that your electronic products are manufactured to your specifications. You can even determine things like the materials to use. If you have many product variants, it is better to outsource the service as you do not have to change your machine settings every time you want a product variant.
An electronic assembly service tends to attract and retain top talent. If you do the assembly yourself, you are unlikely to attract talent to make sure you have a highly reliable application that can withstand the abuse, potential attacks, and harsh environments. By outsourcing the service, you don’t have to worry about training your employees and constantly updating them with the latest technology.
The professionalism offered by electronic assemblies means that you get valuable advice on how to make your products more efficient and effective. The electronic assembly service will have learned from your successes and mistakes, as well as from the mistakes and successes of others. When you outsource, you get different products from the same company, which means you have no compatibility issues and save money.
Conclusión
Las bolas de soldadura sin plomo se utilizan principalmente en aplicaciones con paquetes de chips, protuberancias de obleas de descarga de chips y matrices de rejilla de bolas como componentes LBGA, CBGA y PBGA. Los productos disponibles en esta categoría cubren todo tipo de opciones de aleación, incluidas las sin plomo, eutécticas, con bajo contenido de plomo y de plata, e incluso opciones personalizadas para diversas aplicaciones con requisitos específicos. Sin embargo, dada la tendencia actual en la industria de introducir pastas y productos de soldadura sin plomo, las bolas de soldadura de este tipo en particular son las más solicitadas. Debido al pequeño tamaño de las bolas de soldadura y al hecho de que un solo dispositivo o PCB puede contener miles de estas perlas, definitivamente debe asegurarse de que el producto que se ofrece sea de alta calidad.
Tolerancia y diámetro de bola
La consistencia del diseño es primordial si desea disfrutar del rendimiento predecible y la facilidad de uso de sus bolas de soldadura sin plomo. Es importante que el producto que seleccionó tenga un diámetro uniforme, un diámetro estrecho y tolerancia a los esferoides. Este factor se vuelve aún más importante si el tamaño deseado de la bola de soldadura es menor al promedio ya que en tales casos se debe verificar el diámetro y la tolerancia de esfericidad con mayor precisión (una medida de qué tan redonda o alrededor de la esfera).
Tecnología de fundición de aleaciones para producción.
The process and technology for melting solder alloys are also an important factor to consider. Accurate levels of metal must be maintained in the lead-free solder bumps, and proper process optimization must be maintained to avoid segregation of the alloy, which eventually leads to multiple peaks. Your manufacturer must also be able to ensure consistent production and repeatability of quality parameters from batch to batch. Deviations significantly affect your own SMT for the BGA assembly line.
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