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| Portable data collection |
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| First-in, first-out (FIFO) buffer |
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| Conflict detection for queued command handling in disk drive controller |
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| Machine control system |
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| Transmitting commands over a serial link |
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| Microprocessor with pipeline system having exception processing features |
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Semiconductor device
| Details |
Inventors: Murakami, Gen; Tsubosaki, Kunihiro; Ichitani, Masahiro; Nishi, Kunihiko; Anjo, Ichiro; Nishimura, Asao; Kitano, Makoto; Yaguchi, Akihiro; Kawai, Sueo; Ogata, Masatsugu; Eguchi, Syuuji; Kokaku, Hiroyoshi; Segawa, Masanori; Hozoji, Hiroshi; Yokoyama, Takash
Assignee: Hitachi, Ltd. (Tokyo, JP)
Primary Examiner: James; Andrew J.
Assistant Examiner: Nguyen; Viet Q.
Attorney, Agent or Firm: Antonelli, Terry, Stout & Kraus
As the semiconductor chip is large-sized, highly integrated and speeded up, it becomes difficult to pack the semiconductor chip together with leads in a package. In view of this difficulty, there has been adopted the package structure called the "Lead-On-Chip" or "Chip-On-Lead" structure in which the semiconductor and the leads are stacked and packed. In the package of this structure, according to the present invention, the gap between the leading end portions of the inner leads and the semiconductor chip is made wider than that between the inner lead portions except the leading end portions and the semiconductor chip thereby to reduce the stray capacity, to improve the signal transmission rate and to reduce the electrical noises. |
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DETAILED DESCRIPTION We have investigated the aforementioned semiconductor devices of the prior art and have found the following problems: (1) In the semiconductor device of the prior art, the inner leads are adhered to the circuit forming surface of the semiconductor chip through the semiconductor chip and the insulating films by the adhesive.
Because of the large stray capacity between the inner leads and the semiconductor chip, the semiconductor device has a problem that the signal transmission rate is dropped by the large stray capacity to increase the electrical noises.
(2) Because of the large area of the insulating films, the amount of moisture absorbed is increased so that the absorbed moisture is gasified and expanded in the package during the reflow, thus causing a problem that the package cracking is established by the moisture expansion.
(3) Since the aforementioned insulating films are made of a resin of polyimide, the amount of absorbed moisture is increased so that the absorbed moisture is gasified and expanded in the package during the reflow, thus causing the problem of package cracking.
(4) Since the aforementioned adhesive is made of an acrylic resin, it is degraded by the pressure cracker test or the like, thus raising a problem that the reliability is dropped by the electrical leakage between the leads and the corrosions of the aluminum electrodes.
(5) Since the circuit forming surface of the semiconductor chip is not coated all over with the resin coating of polyimide for protection against alpha rays, there arises a problem that errors are caused by the alpha rays.
(6) The common inner leads (i.
e.
, bus bar inner leads) are used as radiating plates, but the element having a large exothermic portion is not covered all over with the inner leads.
There arises a problem that the radiation is insufficient in an element of 1 watt or higher.
(7) Since the insulating films made of the aforementioned resin of polyimide has a large area, there arises a problem that the semiconductor device is weak in the temperature cycle
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I/O Systems 
