Known Good Die (KGD)
Chips that have been fully tested before being placed into their packages. Chips used in ceramic-based multichip modules (MCMs) are typically fully tested beforehand, because the ceramic substrates are costly to replace if the final package is faulty because of a bad chip.
(http://www.pcmag.com/encyclopedia_term/0,2542,t=known-good+die&i=45849,00.asp)
KGD is a high quality LSI chip, and it has quality guarantee in its chip level and cost more. 特指高质量的大规模芯片, 有保证, 成本较高.
(http://www.tclc.com.cn/tabloidv.asp?id=7141)
Identification of known good die is critical to the economics of high-yield assembly of multichip modules (MCMs). Today’s testing techniques for identifying defective die before MCM assembly typically increase the overall module cost by 10 to 100 per cent. Every die needs to be proven good before assembly into a submodule, since rework can be difficult or prohibitive ---- essentially a tear down and rebuild ---- and repair may tie up the same elaborate, expensive assembly equipment needed to build a full MCM. Once the leads are soldered or otherwise mounted into a Level 1 chip or Level 1 1/2 module, backtracking to test a bad Level 0 die may be impossible, since only a fraction of the die’s probe points may still be exposed for testing. Some removal or rebuild may be necessary to test a chip, and many current processes are so slow, tedious, error-prone, error-inducing, unreliable, and costly that it becomes preferable to discard a whole module rather than replace a chip.
(D. Salzman and T. Knight, “Capacitive coupling solves the known good die problem,” in Proc. IEEE MultiChip Module Conf., Mar. 1994, pp. 95-100)
Known Good Die（已知合格芯片）这一术语形成于90年代初，用于描述准备用于多芯片组件（MCM）的集成电路。因此这些IC是“已经知道”至少能满足与同等封装元器件同样严格的质量与可靠性指标。我们也“知道”这些IC是昂贵的、组装困难的、脆弱的，以及其他一系列负面的特性；其中某些特性实际上是固有的。最近，在微电子工业占领导地位的公司获悉，“Known Good Die”流程在今天高度竞争的环境中对于以低成本生产大批量、高可靠IC的基准线来说非常有利。结果，“Known Good Die”一词被用于描述使IC达到全面要求状态的过程（不论最终的封装外形因素是什么）。
(http://www.eefocus.com/search/forsearch.php?word=KGD%7C0)