Overview Of The Placement Machine
In order to win a place in today's fierce market competition, electronic product manufacturers must constantly find a new way that can reduce product cost and product introduction time, and at the same time can continuously improve the quality of new products. In addition, manufacturing processes and procedures must be improved, and electronics manufacturers must also push semiconductor device manufacturers to incorporate more functions into miniaturized sized programmable integrated circuits (PICs). Thus, for the design and manufacture of high-end electronic products, taking a path of smaller size, higher function and lower price is clearly demonstrated in front of us. In this context, today's programmable integrated circuits have many pins, have strong functions, and use innovative assembly forms. But electronics manufacturers wishing to use the latest PIC devices must overcome some of the problems encountered in the programming process. Simply put, in order to be able to program PCI devices smoothly, some new methods need to be learned. Fuhaoyun provides technical support for JUKI placement machines in mainland China.
business background
For PIC devices, DIP, PLCC or SOIC packages were generally used in the past. However, as the demand for compact, high-performance products increases, more advanced PIC devices are required. Flash memory devices today are available in SOP, TSOP, VSOP, BGA, and tiny BGA packages. High-performance microcontrollers, CPLD devices and FPGA devices can be packaged in QFP, BGA and micro BGA, with pin counts ranging from 44 to more than 800.
Due to the very high pin count and small form factor, most of these components are only available in fine-pitch packages. Fine-pitch components have very fragile leads, with a pitch of only 0.508mm (20 mils) or almost no clearance. So people are looking at the use of PIC devices to meet this challenge. PIC devices with high density and high performance are expensive, require high-quality programming equipment, and require very good process control to minimize component waste.
Fine-pitch components are virtually certain to encounter threats from coplanarity and other forms of lead damage during hand-programmed operations. If the pins are damaged, it may cause problems with the reliability of the solder joints, which will increase the defect rate in the manufacturing process. Likewise, high-density components will actually take longer to program, which reduces production efficiency.
programming on a circuit board
Users of advanced PIC devices face a difficult choice: risk quality problems and hand-program them? Or are you looking for an alternative programming method that eliminates manual touches?
To be able to achieve the latter, manufacturers initially began to use on-board programming (OBP for short). OBP is a simple method of programming the PIC after it is mounted on a printed circuit board (PCB for short). In general, tests or functional tests are carried out on the circuit board. Flash memory, Electronically Erasable Programmable Read-Only Memory (EEprom for short), EEprom-based CPLD devices, EEprom-based FPGA devices, and microcontrollers with built-in flash memory or EEprom, all of which use Programming in OBP form.
In order to meet the usage requirements of flash memory and microcontrollers, the most common way to implement OBP is to use automatic test equipment (ATE) programming with the help of a bed-of-nails fixture. Programming is quite complicated for logic devices, and it is not suitable for programming with ATE pin-on-disk fixtures.
A new OBP technology originally developed based on IEEE specifications to support testing shows a promising future. This specification, called IEEE 1149.1, specifies a series of protocols for boundary scan and has been used in many PIC programming methods.
If electronic product manufacturers want to use the IEEE 1149.1 programming method, they rely on intellectual property protection tools mainly provided by various semiconductor manufacturers. But programming with their tool is very slow. Also, because of their instinct to protect intellectual property, each tool is limited to devices used by a single user. This would be a big drawback if a PIC device on a board was used by multiple users.
All in all, using the OBP method eliminates the need to manually manipulate the device and incorporate programming into testing, as well as slow manufacturing production. However, the time required for programming may also be slow.
ATE dial programming
The original use of ATE equipment was for in-circuit testing of PCB assemblies to find manufacturing defects such as open traces, shorts, missing components, and misalignment of components. A pin-to-disk fixture is an array configuration with spring-loaded test endpoints that creates a mechanical and electrical interface between the PCB and the signal driving circuitry of the ATE test equipment.
Once the PCB is securely connected to the pin-on-disk fixture, the signal driving circuit of the ATE test equipment will send programming signals to the target device PIC through the pin-on-disk fixture and the PCB. In addition to testing for mechanical defects, ATE equipment can also be used to program PIC devices. The programming and erasing of components is embedded in the board test program, which is then used to program the target device.
IEEE 1149.1 Boundary Scan Programming
In order to increase the density and complexity of PCB components, it is very difficult to test circuit boards and components, especially for PCB components with limited space. In order to solve this problem effectively, a boundary scan test protocol (IEEE 1149.1) came into being.
The IEEE 1149.1 test standard enables programming of logic or flash memory devices on assembled circuit boards by an intelligent external device. This programming device forms a connection interface with the circuit board through a standard Test Access Port (TAP for short). All of this requires a JTAG hardware control unit, a JTAG software system, a JTAG-compatible PCB, and a four-wire test access port.
Boundary scan work can be achieved using a specialized dedicated circuit board programming equipment, or another option, using some tools provided by companies such as GenRad, Hewlett-Packard and Teradyne ATE testers in the United States, can be tested in ATE IEEE 1149.1 boundary scan programming works on the device.
One of the biggest advantages of adopting the IEEE standard is that it can program a wide variety of components from different suppliers on the same PCB. This reduces the overall programming time and simplifies the manufacturing process.
Automation Programming (AP) Equipment
PIC technology continues to advance, so new automation programming equipment and technologies keep the same pace. For example, Data I/O's ProMaster 970 automated fine-pitch programming device can program PIC devices in advanced package styles including BGA, Micro BGA, SOP, VSOP, TSOP, PLCC, SON and CSP. Dual pick-and-place (PNP) terminals and optional 8, 10, or 12 sockets maximize device efficiency. The programming device may also be further involved in quality control of the device. For example, coplanarity issues and pin damage are virtually non-existent, as the integrated laser vision system ensures very precise device placement.
Because of the variety of programming interfaces and PNP device configurations, automatic cluster programming can generally be 5 to 10 times faster than ATE programming. Also, these programming tools are designed for programming, not for testing the board or function, so they can provide very good programming quality.
Fine-pitch PIC devices can be very expensive, so reducing the damage rate during manufacturing would greatly improve a manufacturer's break-even point. The automatic programming system that can be applied to most components is also very flexible and can be adapted to advanced package device forms. The ability to combine high productivity, high quality and flexibility results in the lowest available programming price per device often being less than 20% of the ATE programming price.
Choose a programming strategy
Production leaders often consider different ways of programming, and they ask, "Which way of programming is best for me?" There is no one answer that fits all use cases. The content they weigh will generally include: the solution adopted for production efficiency, the scheduling of production line use, the price of PCB, process control issues, defect rate levels, management of suppliers, cost of major equipment, and management of inventory. will have an impact.
Impact on productivity
ATE programming reduces productivity because extra time is added to be able to meet programming needs. For example, if it takes 15 seconds to test to check for defects in the manufacturing process, an additional 5 seconds may be needed to program the component. ATE acts like a very expensive single port programmer. Also, for high-density flash and logic devices that take longer to program, the overall test time required will be longer, which is a headache. Therefore, when the programming time is very small compared to the total test time of the board, the ATE programming method is the most cost-effective method. To increase productivity and to minimize long programming times, ATE programming techniques can be combined with on-board techniques such as boundary scan or one of the many patented methods.
Another solution is to program only the boot code of the target device when the board is being tested. The rest of the programming of the device is done when there is no impact on productivity, typically when the device is functionally tested. However, unless the capability of the ATE is exceeded, the capability of functional test is sufficient, and the most cost-effective programming method for high-density devices is an automated programming device. Case in point: The ProMaster 970 device is configured with 12 ports, capable of programming and laser marking 600 8M flash memories per hour. In contrast, an ATE, or functional tester, would take 60 to 120 hours to complete these programming tasks.
