半导体中BOAC是什么

BOAC,是一种焊垫设于有源电路上方焊接的集成电路结构，也叫“有源电路上凸点”。

下面的英文段落供参考。

A BOAC/COA of a semiconductor device is manufactured by forming a conductive pad over a semiconductor device, forming a passivation oxide film over the semiconductor device including the conductive pad, forming an oxide film over the entire surface of the conductive pad and the passivation oxide film, forming an oxide film pattern defining a bond pad region on the conductive pad, sequentially forming a barrier film and a metal seed layer over the oxide film pattern, the passivation oxide film and the conductive pad, forming a metal layer over the metal seed layer, planarizing the metal layer exposing the oxide film pattern and portions of the barrier film and the metal seed layer, and removing the oxide film pattern by an etching process.

A phenomenon can be noticed in the case study of Samsung. For instance, Samsung sold half of its semiconductors to its subsidiaries. Please take a look at the graph below, which shows that the proportion of buying its own products has increased from 30% to the current 50%, averaging at 40%. We can see from the graph that Samsung establishes an internal market by selling its products to itself. So, just think why Samsung buys its own semiconductors? In my opinion, it gets a huge market by selling products to both external and internal markets. Now we can see its key to success, that is, Samsung can take advantage of its huge market, and in this way, it can achieve "Economy of Scale" earlier than any of its competitors. The definition of "Economy of Scale" is that the increase in efficiency of production as the number of goods being produced increases

When it reaches economy of scale, the result is extremely rewarding, as the cost will be greatly reduced as a result of mass production. To better illustrate my point, I would like to ask you to have a look at the diagram below. You can see two lines here, the purple one stands for Selling cost, while the blue one stands for net sale. Because even for a well-operated company like Nokia, the net sales and selling cost are just leveled off. In fact, this has already been a good sign. Compared with different companies, it is easy to tell that the growth of its net sales tend to exceed that of its selling cost after the expansion of a company, resulting in a drop on its return on asset. And the reason for this is runaway costs.

All in all, let's sum up what was mentioned just now. Samsung has established a system of Vertical Intergration, and the effective operating of this system turns out to be very rewarding: Samsung does not simply make a profit on its semiconductor, its follow-up market is createing even more value instead.Therefore, its return on capital takes an industry-leading position. Moreover, Samsung also enjoys a huge market, which enables it to reach economy of scale more easily than its competitors, hence cutting the cost.

That's all for our report. Thank you for listening.

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