Chip packaging is what happens to a silicon device after it leaves the foundry fabrication line or the “Fab”. The Fab is where the silicon wafer is processed with photo-lithography and hundreds of other steps to create the Integrated Circuits (IC) that are the heart of electronics devices. Billions of gates are combined to form CPUs, GPUs, WiFi, memory and camera sensors.
The Fab does not process individual chips. The process works on a silicon disc called a wafer. After all the processing, the wafer is cut to make the individual chips or dies. Each die is tested and shipped to a packaging manufacturer.
The individual dies are very sensitive to thermal, electric and mechanical stress. Larger structures and tougher materials protect dies and connect them to the rest of the circuit. These packages are highly engineered for performance and cost. This process is performed by “fabless” semiconductor manufactures or OSAT (Outsourced Semiconductor Assembly and Test) facilities.
It gets harder and harder to package dies as the technology node progresses. Ever smaller transistors mean more power consumption on the same sized die and higher thermal load. Greater capabilities mean more interconnects (I/O) and the need for finer pitch connections to the outside world. The IC gate length might be five nanometers (5nm), but the circuit on the Printed Circuit Board (PCB) may have integration issues with a pitch smaller than 50,000nm (0.05mm). The scale difference can be incompatible.
Fine pitch I/O chips need a substrate or interposer layer to connect the chip to the board. Some PCB manufacturers have invested in technology to create smaller PCBs with the finer feature sizes found in substrates. They are converging with substrate manufacturers that invest in larger sizes. These trends will continue towards larger structures with finer features.
Chip Packaging is not “one size fits all”. A memory die has different thermal and electrical requirements than a CPU or a GPU. Camera and photonic sensors have optical requirements on top of electrical, mechanical and thermal requirements.
An OSAT specializing in packaging small memory dies will need to invest in R&D to be able to catch up to companies that specialize in large die CPUs. Customer requirements drive the design, and the same die may have different requirements in different applications. Specialized packaging exists for aerospace, automotive, industrial and commercial applications. The same memory dies used in an aircraft have a different package than those used in a cellphone or camera.
Some packages are generally applicable. Most laptops and desktops have standard sockets or connections for interchangeable or upgrade-able components. It is possible to de-solder and rework a failed component in some cases. Manufacturers invest in design, simulation, testing and field failure analysis to be able to generalize packaging for wide applications.
It is impossible to create one package that fulfills all requirements for all use profiles. We can compare this to household light bulbs and see that even for something relatively simple there are hundreds of options. ICs are much more complicated than light bulbs.
The best package usually ends up being a series of trade-offs between performance, cost, reliability and a dozen other metrics. Chip Scale Packages (CSP) are more suitable for smaller dies, whereas larger dies might need a dedicated heat spreader lid or exposed die for direct thermal solution attachment, for example.
There is also a divergence between the largest manufacturers for general laptop and desktop CPUs. Intel uses the Land Grid Array (LGA) for their flagship CPUs and AMD has Pin Grid Array (PGA) desktop processors even in 2026. In 2024, AMD launched the Ryzen 5000XT for the AM4 Physical Pin Grid Array with 1331 pins. Meanwhile, Apple silicon opted for a Ball Grid Array (BGA) that is soldered directly to the motherboard without a socket. Huawei’s Kirin X90 also uses a permanently soldered BGA.
At the surface, these seem like four similar use cases, but they are not. Apple has an entire system on chip (SOC) while Intel and AMD use BGAs for laptop CPUs because sockets are too thick. While there is some convergence on package styles, there is still a wide range of package configurations.
Every package designed today employs simulation for everything from electrical, electro magnetics, thermal, mechanical, chemical and other physics based solvers. The traditional design-build-test method alone is not feasible for current packages. Experienced finite element analysis (FEA) engineers with specialization in chip packaging can be found in every step of the process, from the fab to the end user.
Simulation is not a substitute for test. It is used to inform the design process to increase the probability of passing test and reducing the design cycle time. Each design iteration incurs unrecoverable costs such as time and management fees. It is far preferable to prevent known bad designs by using physics based simulations. The same tests still get performed on the final design, but getting there is easier and cheaper.
The costs associated with every new chip package design are small relative to the costs associated with new technology nodes at the foundry. There is still great value in delivering a good package. The best chip with a bad package is an unacceptable failed product.
BGA soldering is a mature process in PCB assembly. Stacking dies inside packages and stacking packages in an assembly are methods of fabrication that are evolving every year. The internals of the BGA can include novel elements and continue to evolve. Sophisticated and larger substrates, the use of silicon interposer, system on package and cooling solutions increase the cost of design and manufacturing. These increased costs and long lead times for manufacturing are reflected in the cost of components. The current a high demand for high power computing (HPC) components is similar to the CPU bottle neck from the 2000’s.
Chip shortages can also happen due to global supply chain crises, natural disasters and geopolitical factors. The final cost of the component is not only related just to the chip design process. Often, the profit margin for the company is based on supply and demand more than a purported technological advance itself.
Silicon chips respond to physical stress just as the chip markets respond to market stresses. The market drives performance requirements which in turn drive physical designs. The chip-packaging designs must obey the laws of physics but to be successful, they must also bend to economics. Evolving requirements from the market have a direct effect on the decision making of the engineering teams working to fulfill them. The specialization and stratification in the market should be reflected in your engineering design teams.
Chip packaging is a complex and essential part of electronic manufacturing. It is the transition and connection between the PCB and silicon. The future of chip packaging is being created right now.
Copyright Gil Sharon February 3, 2026 . All rights reserved.