science

Pin grid array

Pin grid array is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Pin grid array rather than just read about it. In short: A pin grid array (PGA) is a type of integrated circuit packaging. In a PGA, the package is square or rectangular, and the pins are arranged in a regular array on the underside of the package.

Key takeaways

Pin grid array belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Pin grid array to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Pin grid array from memory before moving on to harder problems.

Reference excerpt

A pin grid array (PGA) is a type of integrated circuit packaging. In a PGA, the package is square or rectangular, and the pins are arranged in a regular array on the underside of the package. The pins are commonly spaced 2.54 mm (0.1") apart, and may or may not cover the entire underside of the package. 1.27 mm (0.05") is commonly used with higher pin count PGAs. PGAs are often mounted on printed circuit boards using the through hole method or inserted into a socket. PGAs allow for more pins per integrated circuit than older packages, such as dual in-line package (DIP).

Chip mounting

The chip can be mounted either on the top or the bottom (the pinned side). Connections can be made either by wire bonding or through flip chip mounting. Typically, PGA packages use wire bonding when the chip is mounted on the pinned side, and flip chip construction when the chip is on the top side. Some PGA packages contain multiple dies, for example Zen 2 and Zen 3 Ryzen CPUs for the AM4 socket.

Flip chip

A flip-chip pin grid array (FC-PGA or FCPGA) is a form of pin grid array in which the die faces downwards on the top of the substrate with the back of the die exposed. This allows the die to have a more direct contact with the heatsink or other cooling mechanism. FC-PGA CPUs were introduced by Intel in 1999, for Coppermine core Pentium III and Celeron processors based on Socket 370, and were produced until Socket G3 in 2013. FC-PGA processors fit into zero insertion force (ZIF) motherboard sockets; similar packages were also used by AMD.

Material

Ceramic A ceramic pin grid array (CPGA) is a type of packaging used by integrated circuits. This type of packaging uses a ceramic substrate with pins arranged in a pin grid array. Some CPUs that use CPGA packaging are the AMD Socket A Athlons and the Duron. A CPGA was used by AMD for Athlon and Duron processors based on Socket A, as well as some AMD processors based on Socket AM2 and Socket AM2+. While similar form factors have been used by other manufacturers, they are not officially referred to as CPGA. This type of packaging uses a ceramic substrate with pins arranged in an array.

Organic

An organic pin grid array (OPGA) is a type of connection for integrated circuits, and especially CPUs, where the silicon die is attached to a plate made out of an organic plastic which is pierced by an array of pins which make the requisite connections to the socket.

Plastic

Plastic pin grid array (PPGA) packaging was used by Intel for late-model Mendocino core Celeron processors based on Socket 370. Some pre-Socket 8 processors also used a similar form factor, although they were not officially referred to as PPGA.

Pin layout

Staggered pin The staggered pin grid array (SPGA) is used by Intel processors based on Socket 5 and Socket 7. Socket 8 used a partial SPGA layout on half the processor.

It consists of two square arrays of pins, offset in both directions by half the minimum distance between pins in one of the arrays. Put differently: within a square boundary the pins form a diagonal square lattice. There is generally a section in the center of the package without any pins. SPGA packages are usually used by devices that require a higher pin density than what a PGA can provide, such as microprocessors.

Stud A stud grid array (SGA) is a short-pinned pin grid array chip scale package for use in surface-mount technology. The polymer stud grid array or plastic stud grid array was developed jointly by the Interuniversity Microelectronics Centre (IMEC) and Laboratory for Production Technology, Siemens.

rPGA The reduced pin grid array was used by the socketed mobile variants of Intel's Core i3/5/7 processors and features a reduced pin pitch of 1 mm, as opposed to the 1.27 mm pin pitch used by contemporary AMD processors and older Intel processors. It is used in the G1, G2, and G3 sockets.

Illustrations

Worked examples

Example 1 — a first encounter with Pin grid array

Start with the simplest possible case. Write down what Pin grid array claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Pin grid array before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Pin grid array ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Pin grid array

In research: Pin grid array appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Pin grid array in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Pin grid array is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chip carriers, so understanding it makes those chapters shorter.
In everyday life: Look for Pin grid array outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Pin grid array in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Pin grid array means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Pin grid array out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Pin grid array in simple terms?

A pin grid array (PGA) is a type of integrated circuit packaging. In a PGA, the package is square or rectangular, and the pins are arranged in a regular array on the underside of the package.

Why does Pin grid array matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Pin grid array?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Pin grid array.