BGA in Forensics: Data Recovery Machines


BGA in Forensics: Data Recovery Machines

In today’s business world, the protection of data is a chief concern among companies of all sizes. We keep data on computer hard drives and in digital storage systems for everything from product inventory and sales transactions to credit card numbers and customer-receipt records. If data is ever lost, a business could suffer major setbacks as it struggles to retrieve its vital records.

With so much monetary interest at stake, data must be backed up at all times and in multiple places. Despite the common-sense practices that most businesses employ to protect their data, computer hard drives will sometimes fail before unique documents can be duplicated or retrieved. And the risk of data loss is often higher with smaller business operations — especially those that operate “on foot” and run payment transactions via smartphones.

Of course, data loss is not the only problem that threatens computer systems in the business world. Hard drives often get clogged with redundant files that consume space and memory, yet are difficult for users to find and eliminate. In rare cases, rogue company employees either leak classified company info or delete key files which must then be retrieved.

Each of these scenarios — data loss, data redundancy and wrongful data deletion — require unique skill sets to solve.

What Is Data Recovery and How Does It Differ From E-discovery and Computer Forensics?

For starters, each of these three fields deals with computer data. As such, they all fall under the realm of “digital” technology — i.e. electrons. The purpose of each is to take data that is indecipherable to common human beings and translate the information into an accessible format.

However, despite some of the similarities between the three fields, there are also significant differences. Namely, the fields of data recovery, e-discovery and computer forensics each involve different skill sets that require their own tools and work facilities. Basically, each field involves different sets of knowledge.

Data Recovery

In the field of data recovery, broken hardware and software is “operated on” in an effort to recover data that would otherwise be lost. Data recovery is typically performed on a hard drive — internal, external or thumb-drive — that has become unresponsive. In the case of a computer that fails to reboot after a crash, and where diagnostics reveal the problem is down to a failure of the internal hard drive, the drive itself can be handed to data-recovery specialists in an effort to recover lost files.

In cases where a hard drive becomes unreadable, the drive itself will have incurred either physical or electronic damage and possibly both. In scenarios such as these, data recovery will likely be the only way to salvage the data that was

never backed up from the drive in question. The recovery of said data can sometimes be achieved with maintenance of key electronic parts on the disc or possibly by a replacement of the read/write heads that transfer data to and from the drive.

If a hard drive is fully intact at the time that it becomes non-responsive, the problem is likely due to a corrupted partition structure. Several techniques may be used to repair a damaged partition, some of which involve the use of tools that can help rebuild the file structure. Alternately, tools can be employed to extract files from a damaged partition.

On older hard drives, hex editors were sometimes used to rebuild partitions manually, but this has become an insufficient method in light of today’s terabyte-sized hard drives, which generally include too many millions of files for any such recovery method.

Overall, the process of data recovery works at the macro level, where data is rescued in bulk quantities with little mind for the individual files. While there are no universal standards within the industry of data recovery, most of the work entails technical operations on disk drives and data-storage components that have suffered physical or electronic damage.

E-discovery

The field of electronic discovery, by contrast, concerns intact hardware and software. The main object in this line of work is to “de-dupe” volumes of data that have been excessively duplicated on a hard drive. A general task will involve scanning a hard drive to find hidden, redundant duplicates of emails and files that have consumed excessive partition space.

The problem of file redundancy is symptomatic of computers and email servers, which are generally programmed to duplicate files and emails. To solve this problem, e-discovery tools are employed to find and remove redundant files and reduce disk usage to a more functional level. Unlike data recovery, e-discovery is a practice governed by the Federal Rules of Civil Procedure (FRCP).

Computer Forensics

The field of computer forensics combines aspects of data recovery and e-discovery. The purpose here is to retrieve data that has either been lost or deleted — sometimes intentionally so — on a hard drive or data-storage component. Work of this type is performed by a computer forensics examiner (CFE), who employs reading and scanning methods to salvage lost files.

When the task involves recovering deleted email, the CFE must sift through remnants of data and unallocated space to find text that is no longer present in the form of readable files. Methods include cache and log-file searches as well as scans of internet history and Outlook files. In some cases, existing files are searched for prior data that has since been overwritten with new information.

Computer forensics is often employed in criminal investigations where incriminated data has been stored on — and in some cases deleted from — a hard drive. In cases like these, a CFE might be subpoenaed to testify in a court of law. The evidence will be cross-examined and the CFE will have to defend or elaborate on his or her findings.

Data Recovery vs. E-discovery vs. Computer Forensics

Generally, data recovery is employed on single hard drives and data storage systems. The company that performs the recovery work will use their own methods and earn business through a good reputation.

Electronic discovery, by contrast, works by a standardized set of processes that are preferably pre-planned for each application, though jobs that require quick turnaround are often seen throughout the industry. A given e-discovery task will typically encompass large computer systems with multiple user accounts.

Computer forensics could involve a single hard drive or a large, network-wide database. The work will entail data retrieval with possible legal ramifications and must therefore be defensible within a court of law by the CFEs involved.

Use of BGA Rework Stations in Data Recovery on Cell Phones

Ball grid array (BGA) technology is used to apply surface-mount technology (SMT) pieces onto printed circuit boards (PCBs). Along the lower sides of each chip is a number of pads that contain tiny balls of solder. The balls are melted into place with reflow soldering.

On a conventional IC, the amount of available space for pins is limited. With BGA — which reduces the amount of space needed on a PCB — the whole bottom portion of a chip can be allocated for signaling.

BGA does have its share of drawbacks in cases where forensic equipment must be applied. With most surface mounts, a probe can be set to a pin to extract data from a chip. This allows investigators to read the memory contents, yet keep the

unit free of damage. However, BGA will cause bonding to occur between chips and PCBs. Consequently, a chip and PCB must be desoldered from one another before any forensics can be performed.

The task of desoldering requires proper care to ensure no damage is incurred by the circuitry. Residue from solder needs to be cleared away so it does not leave the chip pads at risk of circuit failure. Next, the chip is brought back to its pre-solder state through a process known as reballing. In some cases, the forensic analyst can read the memory contents directly through a connection with the pads.

Reballing

A chip package will usually need to have intact solder balls to be read by most devices. With the process of reballing, the solder balls on the bottom side of a package can be restored. Reballing involves the use of a stencil that comes equipped with tiny holes that mirror the dimensions of the pads.

To fill each of the holes, solder paste is distributed in even proportions with the stencil. The next step involves the application of reflow, which allows balls to form from the applied solder paste. These balls are fastened to the chip pads.

With BGA reballing, the balls and stencil must have matching dimensions. As such, it can be difficult to obtain a stencil with the proper dimensions when BGA reballing is needed on a mobile phone, as mobile phones are equipped with boards of various dimensions and configurations.

Reading Memory

When forensics must be performed on a memory circuit, a device programmer is sometimes used in the process. Device programmers can be fitted with numerous adapters, such as the 40-lead DIP packages and Intel 28F640 adapters.

Additionally, software is required to interpret the chip data. The type of software that will work could all depend on the configurations of the pin. However, a majority of software programs intended for this kind of use are applicable to a range of devices. Numerous devices are equipped with inbuilt checksum code that sifts through inconsistencies as the memory is read. The software employed during forensics must be compatible with this code.

During forensic analysis on the memory of a mobile phone, a device programmer might also be employed to read the BGA circuits. In order for this to work, the dimensions of the balls must be mirrored by the adapter pins. Chip connections are enabled with either pogo pins or y-shaped springs. The former can be applied straight to the chip pad, but the latter requires a ball to achieve the connection. Reballing can be skipped with pogo pins, which are therefore preferable for tasks that involve forensic analysis.

Desoldering

The desoldering process can be employed with reflow ovens or simple irons. For the forensic, the primary concern during this step is the possibility that damage could be incurred by the unit. An IC can only withstand a limited number of reflow-temperature heatings. Intel BGA circuits are designed to withstand three such reflow applications.

In forensic tasks that involve PCBs with double-sided SMT, only one temperature can be used. However, this can be too confining if the job calls for both desoldering and reballing. To prevent damage to the unit, the right temperature must be sustained throughout the process. Due to the lack of mounting technology involved, the heating process must be applied to the entirety of the chip.

The solder reflow temperature should remain below the maximum amount of heat allowed. If vapor makes contact with the circuit substrate, cracks could form. To prevent the appearance of moisture during this process, pre-baking is advised.

The steps required of this process preclude the use of manual soldering tools. Desoldering tasks should be confined to stations with a programmable temperature gradient and where components can be removed automatically. A station of this type will generally rely on a mix of air-based convection and infrared radiation heating. The necessary heating curves can be programmed and employed through the attached air nozzle.

BGA Equipment for Data Recovery From Precision PCB Services

At Precision PCB Services, Inc., we offer products and services that boost the quality and efficiency of printed circuit boards. In doing so, we help customers trim waste and lower the number of defects that would otherwise be inevitable when products fail.

The team here at Precision PCB aims to offer more than just an additional machine for your arsenal. We want to provide you with a thorough rework system. With the BGA Rework Station for data recovery, you get all the components necessary to perform the applicable processes at your home or work space. When you purchase one of our BGA Rework Stations, you also receive employee training and lifetime technical support. All of the equipment sold by Precision PCB is backed by a one-year warranty.

As a B2B company, we help customers recognize the types of defects that occur during the manufacturing process. We then lead our customers along the improvement path with process development and employee training.

Don’t give up on your circuit board as broken unless our team confirms that to be the case. Whatever scrap you bring in, we can restore it to working condition in a vast majority of cases. Since 1991, we have remained committed to the assembly and repair of printed circuit boards and electronic products. We honor that commitment with our products, services, training and consulting.

With our circuit board repair and defect analysis services, we help our customers improve the quality of their manufacturing. To learn more about our products and services, browse our catalog of BGA Rework Stations and contact us today to speak with one of our representatives.