QFPパッケージ-一般的に使用される部品パッケージの種類

Walk into any electronics lab, look inside your smartphone, or open up a contemporary appliance, and you’ll likely find yourself face-to-face with a diminutive, square ICチップ with legs on all four sides. Say hello to the QFP, or Quad Flat Package – an integrated circuit (IC) package workhorse that invisibly powers devices surrounding us by the thousands. While more glamorous packages like BGAs (Ball Grid Arrays) get the headlines, humble QFP remains highly relevant and still widely used today.

Today, FS Technology, the ultimate turnkey PCBA manufacturer in China, will introduce you to the QFP Package, its types, features, applications, and its differences with other IC packages.

QFPパッケージとは何ですか？

QFPあるいは クワッド・フラット・パッケージ. Basically, a QFP is a surface-mount technology (SMT) package. That is, it’s supposed to be soldered on the surface of a PCB, not inserted through holes like older Dual In-line Package (DIP) devices. The telltale signs are:

Quad: Leads (the little metal “legs”) extend out from all four sides of the package.
Flat: The package body itself is quite flat and low-profile.
Package: It is the protection for the sensitive silicon die inside, providing electrical contacts to the PCB and a minimal environmental shielding.

This package has a square or rectangular shape, with component leads extending from all four sides of the package body. The leads can be bent at right angles and distributed evenly along the sides of the package.

The leads on a QFP package are arranged in a grid pattern. They are thin and flexible, designed for SMT assembly to PCBs. To ensure good electrical contact with the PCBパッド, the leads are typically plated with conductive materials like gold or tin.

Mounting a QFP package onto a PCB involves aligning the IC leads with the PCB pads and then soldering them in place using a soldering iron or a reflow oven. During the はんだ付けプロセス, the solder paste on the PCB pads melts and connects the QFP leads to the pads. The surface tension of the molten solder secures the QFP package onto the PCB.

QFPパッケージの主な特長

One of the key advantages of QFP packages is their use of surface-mount technology. SMT is a faster and more reliable method of assembling 電子部品 onto a printed circuit board (PCB) than traditional through-hole technology (THT) PCB assembly. QFP IC packages with SMT leads can be placed onto the PCB using automated pick-and-place machines, significantly reducing the time and cost of assembly.

Lead Count: QFPs excel at providing a high number of connections (I/O pins) in a minimal space. Common lead counts range from 32 to well above 200.
ピッチ： This is the distance between the centers of adjacent leads. Standard QFPs traditionally used a 0.8mm or 1.0mm pitch. However, with the trend towards miniaturisation, 0.5 mm and even 0.4 mm have emerged.
Body Size: Proportional directly to lead count and pitch. More pins or finer pitch give a larger body size for the same function.
素材です。 Typically made of plastic (most common, lowest price) or ceramic (for improved reliability, thermal performance, or hermetic seal in harsh environments – also called CQFP at times).
Gull-Wing Leads: The leads are shaped outward and downward in a special “gull-wing” form, making them visible and accessible from the side after soldering. This is necessary for inspection and rework.

QFP ICパッケージスタイル

バンパークワッドフラットパッケージBQFP)):この形式のクワッド・フラット・パッケージには、はんだ付け前の機械的損傷からリードを保護するために、四隅に保護用の延長部があります。リードのピッチが細かいため、QFPはピンの折り曲げや損傷を受けやすい。

Bumpered Quad Flat Package with Heat Spreader (BQFPH): This quad-flat package includes pin protectors at the corners to prevent pin damage and heat spreaders to dissipate higher levels of power.

Fine-pitch Quad Flat Package (FQFP): As the name suggests, this is a quad-flat package with a fine pitch for the pins.

Ceramic Quad Flat Package (CQFP)):このタイプのクワッド・フラット・パッケージは、セラミック・パッケージの高品質バージョンにアップグレードされる。

Low-profile Quad Flat Package (LQFP)):メートルQFPまたはMQFPのバリエーションで、高さ問題を解決するためにボディの高さを1.4mmと薄くしています。標準的なリードフレームのフットプリントは2.0mmで、リード数は32～256、ボディサイズは5x5mm～28x28mmです。

Metric Quad Flat Package (MQFP)):標準的なQFPが採用しているメートル法とは対照的に、ピン間隔やその他の寸法がメートル法で定義されたQFPの一種。

Plastic Quad Flat Package (PQFP): This is a QFP that uses plastic as its packaging material.

Thin Quad Flat Package (TQFP)):厚さ約1mmの薄型QFPパッケージ。

Plastic Quad Flat No-Lead (PQFN) Package: This is a standard QFP package with a plastic body and no leads extending from the sides of the package.

クワッドフラットノーリード（QFN） )パッケージQFPパッケージで、パッケージ側面からリードが伸びていない。その代わり、リードはパッケージの下側にあります。

QFP vs. Other IC Package

QFP vs. ディップ: QFP は larger, もっと見る densely packed, と faster. DIP is mostly obsolete for new designs except for very simple chips or prototyping.

QFP vs. SOIC: SOIC (Small Outline IC) has leads on two sides only. QFP offers もっと見る pin density for complex chips.

QFP vs. QFN: QFN has leads underneath (no gull-wings) and typically has a thermal pad. QFN is generally smaller, もっと見る suited まで熱, but harder to visually inspect and rework. QFP leads are more accessible.

QFP vs. ビーゲー: BGA uses an array of solder balls at the bottom. BGA possesses the highest pin density and best electric performance for chips that are extremely 高速. BGAs are, however, extremely difficult to inspect and rework without an レントゲン facility. QFP takes its ease of access and rework オン.

Tips for Working with QFPs (Especially Fine-Pitch)

PCB Design Matters: Give correct pad size and spacing according to the datasheet. Put はんだマスク dams between the pads. Include a good fiducial marker.

ステンシル Matters: A quality, laser-cut stencil of correct aperture shape and size is not to be trifled with in applying the correct amount of はんだペースト.

Reflow Profile: Follow the recommended supplier’s profile very closely. Preheat ramp is critical in preventing tombstoning or solder balling.

検査: 用途 automated optical inspection (AOI) if possible. Hand inspection requires good lighting and magnification.

Rework: Invest in a good temperature-controlled hot air station with proper nozzles. Use plenty of flux and low airflow initially. Have quality solder wick and fine-tip soldering iron on standby.

QFPパッケージの用途

This packaging form is widely concerned by the electronic application market, especially in telecommunication equipment, 家電と 産業制御PCBA.一般的に使用される電子機器には以下のようなものがある：

マイクロプロセッサー
デジタル・シグナル・プロセッサー（DSP）
メモリーチップ
FPGA（フィールド・プログラマブル・ゲート・アレイ）
電源管理IC
オーディオ・ビデオ処理IC

結論

In brief, QFP packages are a very common packaging style for electronic components due to them being tiny in size, possessing surface mount technology, high number of leads, high thermal performance, and low profile. With every innovation in packaging methods, the QFP, particularly its low-profile and thin variants (LQFP/TQFP), remains an evergreen in electronics manufacturing. The next time you see that little square chip with legs walking along all four sides, tip your hat to the QFP – the steady workhorse quietly making modern electronics possible.