All these steps that you didn’t imagine when designing a CPU
Submerged chips, ultrasonic scanners, thermal imaging… These are the unexpected treatments that certain processors undergo during their development.
In a previous article, we saw how Intel’s Malaysian factories transform the wafers made in the USA, Europe and Israel. But contrary to what one might think, the factories of what we formerly called the countries of the South are not limited to assembly (which is nevertheless and is becoming even more a critical step in the production of chips, as we we saw it).
Indeed, Intel Malaysia actively contributes to the design of future processors, which travel back and forth between the headquarters in the United States, the foundries in the aforementioned regions and the clean rooms in Malaysia. As part of the trip to which Intel invited us, we visited several laboratories and workshops essential to the development of new processors.
Design and Development Lab
In our previous article, we detailed the assembly steps for processor models that are already marketed (Sapphire Rapids) or will be soon (Meteor Lake). We have seen that 100% of chips are tested in this almost fully automated process, not only to rule out failing copies, but also to determine which chips from the same batch can become which processor benchmark (Core 3, 5 , 7 or 9, with or without GPU, unrestricted or not…).
But before launching mass production, Intel’s Malaysian factories are also testing processors still under development on another scale, in its ” design and development laboratory », adjacent to the production lines. Here, dozens, even hundreds of computers “ open bench » are lined up on several aisles and several rows of laboratory tables. The processors engineering sample» are subject to load scaling tests and compatibility tests with all kinds of components (RAM, SSD, GPU, etc.) and peripherals (screens, keyboards, mice, storage media, webcams, etc.). Special motherboards allow you to disable specific functions to isolate the cause of possible problems.
Other test benches, equipped with a centralized liquid cooling system, are used to test and adjust the thermal and electrical specifications (voltage, etc.) of future processors. We test processors from -10°C to 10% beyond their “Tjunction max”, the temperature from which they limit their performance to avoid overheating. The Tjmax is often 100 or 105 °C. Engineers can adjust “hundreds of architectural settings” depending on the results.
Further, the integrity of electrical signals and compliance with specifications, for example of the PCI-Express bus, is verified using high-bandwidth waveform generators and oscilloscopes. In the photo opposite, the signal does not cross the “eye» green in the center, so the test is successful.
The laboratory finally provides services to “OEM», that is to say to computer manufacturers (Lenovo, Dell, HP, etc.), in order to contribute to the development of models adopting new generations of processors.
Failure Analysis Lab
Testing hundreds of processors, from the first samples to the ramp-up of mass production, makes it possible to detect and correct design or manufacturing process defects. In the event of a problem, the processor still under development undergoes an in-depth, low-level diagnosis, looking for the “root cause” (literally “root cause“).
Intel’s factories in Malaysia include a laboratory dedicated to analyzing failures, the “Failure Analysis Lab“, in which some faulty processors are “autopsied“. Engineers have an arsenal of tools worthy of forensic science.
They have microscopes enabling them, for example, to detect poor alignment of the solder balls between thedieand the substrate. Alternatively, they can inject current through microprobes and use thermal imaging to detect a short circuit. But the most impressive is an ultrasound scanner capable of “see» through a processor to detect imperfections between its layers, for which the processor is immersed in a few millimeters of liquid (water?).
System Integration and Manufacturing Services
The equipment described so far certainly uses cutting-edge technologies, it is certainly sometimes specific, but it nevertheless comes from other manufacturers. However, for certain even more specific needs or for questions of industrial secrecy, Intel sometimes designs and manufactures its own hardware.
In Kulim, Intel factories house the “System Integration and Manufacturing Services» (SIMS), literally manufacturing and system integration services, which manufacture and test processor test equipment.
It is notably here that Intel manufactures its High Density Modular Tester (HDMT), the devices which test and classify chips (Core 5, 7, 9, etc.) in the test cells, at the time of “die fate» described in our previous article. These testers are modular, because they are composed on the one hand of a box housing the electronics and on the other hand of a (large) removable card allowing them to be adapted to this or thatsocketprocessor.
The SIMS section also manufactures High Density Burn-In Testers (HDBI), responsible for the thermal and electrical tests described at the beginning of this article, as well as System Level Testers (SLT), which test processors in real conditions, and Reference Validation Platforms (RVP), the various motherboards used during processor development for the tests described throughout this article.
The complexity of a processor
Our two summary and popularization articles reflect the complexity of the processor design and manufacturing processes, which reflects their own complexity. This innumerable equipment makes it possible, after so many stages, to design processors that are more and more powerful, more and more efficient, and more so in recent years since the great return of AMD and the expansion of Apple in the computer market. semiconductors.
However, it remains for us to relate the most important and impressive stage in the manufacture of a processor: that of the production ofwafersin the “fabs» in the United States, Ireland or Israel. As a reminder, it is in these factories, perhaps the most advanced on Earth, that we “engrave” at the nanometric scale billions of transistors on silicon wafers. We will of course answer “here» if we are invited!
