RU175486U1 - SEMICONDUCTOR CASE - Google Patents

Abstract

The proposed utility model relates to the designs of microelectronic products, namely to semiconductor devices and integrated circuits, the crystals of which are enclosed in cases used for mounting a semiconductor crystal. The technical result of this utility model is to increase the strength of the body of a semiconductor device. The specified technical result is achieved in that, in contrast to the known device, in the proposed case of a semiconductor device containing a plastic base with metal terminals and a seat for a semiconductor crystal and a cover sealed to the base, forming a cavity above the semiconductor crystal, the cover is made of ceramic. 3 ill.

Description

The proposed utility model relates to the designs of microelectronic products, namely to semiconductor devices and integrated circuits, the crystals of which are enclosed in cases used for mounting a semiconductor crystal.

Known cases of a semiconductor device containing an inorganic base made of non-conductive material with metal leads and a seat for a semiconductor crystal, a cavity for mounting a semiconductor crystal and a lid sealed to the base from the cavity side for mounting a semiconductor crystal (see, for example, Gotra Z .U. Technology of microelectronic devices: a guide. - M .: Radio and communications, 1991: silt, p. 475).

When using such a case, after mounting the crystal on the base and attaching it to the terminals, a lid is installed, as a result of which a hollow enclosed volume is formed. As an inorganic base, glass, ceramics, metal with insulators through which metal leads pass are used. Covers, depending on the requirements for the semiconductor device, are made of the base material - glass (if an optical signal is required to connect to the crystal) and metal (if additional shielding of the crystal from external electromagnetic fields is necessary).

The advantage of this housing is the convenience of checking the tightness of such a housing, for example, for leaks using a helium leak detector. The main disadvantages are the complexity of manufacturing and the high cost of the case.

Known cases of a semiconductor device containing a frame with metal leads and a seat for a semiconductor crystal, with flexible leads, which are fully pressed into the polymer organic material (see, for example, Kurnosov A.I., Yudin V.V. Production technology of semiconductor devices. Textbook: Handbook for the specialties "Semiconductors and Dielectrics" and "Production of Semiconductor Devices", Moscow, "Higher School", 1974. p. 296).

The advantages of this building are its low complexity, the group nature of the technology and the ability to automate the production process. The disadvantages of polymer plastic cases are their leakage, since during the manufacture and operation of such a semiconductor device, gaps to the crystal of the semiconductor device through which moisture penetrates are formed at the points of contact between the metal terminals and the polymer organic material, as a result of which corrosion of metal tracks and crystal failures are observed. In addition, the strength of such cases is small and when used in critical equipment, for example, in life support systems, military equipment, and transport, where in emergency situations the semiconductor device is subjected to high mechanical stresses, the case can be destroyed (see, for example, https : //www.drive2.ru/b/2615302).

The cracking of the housing occurs at the locations of the concentrators of mechanical stresses, for example, at the places where the metal outlet exits from the plastic base. Voltage concentrators reduce strength by up to 20 times. Typically, when pressing the body to increase strength, fiber additives such as fiberglass are introduced into the plastic. However, when pressing a case with fibrous additives due to the presence of a embedded part (metal leads), it is difficult to get the fibrous material of the plastic case into the spaces between the leads and gaps are formed in these places, which cause leakage of the case. The second way to prevent cracking of the case is its sticker on a solid metal insulated base, but in this case the volumetric installation of the equipment is difficult.

These shortcomings were partially eliminated in the case closest to the proposed case of a semiconductor device containing a plastic base with metal leads and a seat for a semiconductor crystal and a cover hermetically attached to the base, forming a cavity above the semiconductor crystal (see, for example, 1998 GaAs Mantech Jong- Tae Kim, Ki-Sung Ham, “Air-cavity Plastic Packages and new sealing methods using a liquid ruff,” 127). In this case, the lid located on the side of the crystal landing is made of plastic.

The presence of a cavity in the body of a semiconductor device allows you to check its tightness both after manufacturing and after testing for durability.

The disadvantages of such cases, as well as the previous analogue, are low strength.

The technical result of this utility model is to increase the strength of the body of a semiconductor device.

The specified technical result is achieved in that, in contrast to the known device, in the proposed case of a semiconductor device containing a plastic base with metal terminals and a seat for a semiconductor crystal and a cover sealed to the base, forming a cavity above the semiconductor crystal, the cover is made of ceramic.

Since the strength of ceramics is higher than the strength of the used flat plastic covers and it does not contain mechanical stress concentrators, the cover begins to play the role of a flat strong base for installation and there is no need to stick the device during volumetric installation.

The essence of the proposed utility model is illustrated by figures 1, 2 and 3. In FIG. 1 shows a section of the proposed housing of a semiconductor device with a cavity in the base. In FIG. 2 shows a top view of the proposed housing of a semiconductor device. In FIG. 3 shows a section of the proposed housing of a semiconductor device with a cavity formed by the lid.

With reference to FIG. 1, 2, 3 are indicated:

1 - plastic base;

2 - metal output;

3 - seat;

4 - semiconductor crystal;

5 - wire connection (crystal-case);

6 - ceramic cover;

7 - glue.

The device and manufacturing process of the proposed housing of the semiconductor device is described below.

The housing of the semiconductor device, contains a plastic base 1 with metal terminals 2 and a seat 3 for a semiconductor crystal 4 and a ceramic cover 6, hermetically connected by glue 7 to the base from the location of the semiconductor crystal.

A plastic base 1 with metal leads 2 and a seat 3 is made by injection molding a brass part containing metal leads 2 and a seat for crystal 3 with thermosetting plastic. When assembling the semiconductor device, the crystal 4 is mounted, soldered with POS-61 solder to the seat 3, and then the flexible leads 2 from the aluminum wire are welded with ultrasound. Then seal with a lid 6 of corundum ceramics type VK94-1, attaching it with glue 7 in a controlled environment of dried air or nitrogen. Next, a leak test is carried out for small leaks in a helium leak detector, a leak test for large leaks in an elgas medium of electrical parameters and gross leaks.

The strength of the manufactured SO-8 type casings with dimensions: length 9.4 mm, width 6.2 mm, and thickness 4.4 mm was determined by three-point bending. The load was applied from below by two prisms along the length of the body at a distance of 3.7 mm from the center and one prism from above in the center of the body. The test results are shown in table 1.

Таким образом, применение керамической крышки увеличивает прочность корпуса.

Thus, the use of a ceramic cover increases the strength of the housing.

Claims (1)

The case of a semiconductor device containing a plastic base with metal terminals and a seat for a semiconductor crystal and a cover sealed to the base, forming a cavity above the semiconductor crystal, characterized in that the cover is made of ceramic.

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