JPH01117350A - Resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To lessen a thermal strain and to improve the moldability of a resin by a method wherein the thickness of the island of a lead frame, on which a semiconductor element is installed, is formed in half or less of the thickness of the other part of the lead frame compared to that of the other part. CONSTITUTION:A lead frame 22 of a semiconductor device 21 is formed integrally with a lead frame frame 3, an island 24 which is the central part of the frame 3, and suspension leads 5, by which the frame 3 and the island 24 are coupled with each other, and a semiconductor element 6 is fixed on the island 24 with a bonding agent 7. Inner leads 8 formed integrally with outer leads 11 connected electrically to an external device are connected electrically to the element 6 by wires 10. Moreover, the thickness of the island 24 is formed in half or less of the thickness of the other part of the lead frame 2. For example, in case the thickness of the whole device 21 is 1.2mm, the thickness of the element 6 is formed in a thickness of 0.4mm.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a resin-sealed semiconductor device in which leads are connected to a semiconductor element bonded to an island that is part of a lead frame and then sealed with resin. It is.

(Prior Art) FIGS. 3 and 4 show a conventional resin-sealed semiconductor device of this type, FIG. 3 being a vertical cross-sectional view thereof, and FIG. 4(a)
4(b) is a plan view of the lead frame, and FIG. 4(b) is a plan view of the lead frame.
) is an AA cross-sectional view. In the figure, a lead frame 2 of a semiconductor device 1 includes a lead frame frame 3 formed in a rectangular frame shape from thin plate material, a rectangular island 4 located at the center of the lead frame frame 3, and a suspension connecting these members 3 and 4. It is integrally formed with the lead 5, and the lead frame frame 3
, air conditioner 4, and air conditioner 4 are formed to have the same thickness. A semiconductor element 6 is fixed on the island 4 with an adhesive 7, and around the semiconductor element 6, a plurality of inner leads 8 are arranged between each other and the lead frame frame 3. They are connected by an integrally formed tie bar 9. The tip of each inner lead 8 is bent into a double-shape and is close to the semiconductor element 6 , and the tip and the semiconductor element 6 are electrically connected by a wire 10 . Each inner lead 8 also has a lead frame frame 3.
Outer leads 11 are integrally formed and supported by the outer leads 11, and each outer lead 11 is electrically connected to an external device by a lead wire (not shown).

The semiconductor element 6 and other members including the tip of the inner lead 8, which is the center of each member assembled in this way, are usually sealed with a semiconductor sealing resin 12 by transfer molding or the like to protect them from the external environment. has been done.

Lead frame 2 of such a resin-sealed semiconductor device 1
The thickness of the lead frame 3 is required to be at least a predetermined value due to the requirement for lead bending strength in the final product.
It is also necessary for the thickness to be at least a predetermined value. Conventionally, the lead frame 2 has a uniform thickness of at least a predetermined value, for example, a thickness of 0.15 m or more.

On the other hand, the semiconductor element 6 is 1 of the projected area of the entire semiconductor device 1.
In the case of a large chip size that occupies /3 or more,
Since thermal strain deformation of the semiconductor device 1 due to mismatching of linear expansion coefficients of the members constituting the semiconductor device 1 becomes a problem, in order to eliminate this problem, it is necessary to provide the semiconductor element 6 at an optimal position.

Furthermore, the balance between the thickness of the encapsulation resin above the semiconductor element 6 and the thickness of the encapsulation resin below the island 4 during molding of the semiconductor encapsulation resin 7 affects the flow behavior of the encapsulation resin 12. If this balance is disrupted, the flow of the sealing resin 12 will become uneven and the quality of the product will deteriorate, so it is necessary to set this appropriately. Note that the protrusion height of the wire 10 that protrudes upward from the semiconductor element 6 is usually 0.
．． 2 to 0.3 ■ is required.

(Problems to be Solved by the Invention) However, in such a conventional resin-encapsulated semiconductor device, the thickness of the entire semiconductor device l is 1.2 mm, of which the thickness of the semiconductor element 6 is 0.4w
a, lead frame 2 whose coefficient of linear expansion is close to that of the semiconductor element 6;
(for example, 42% N1-Fe) is 0.2 mm thick, and the adhesive 7 is 0.05 mm thick to minimize deformation due to thermal distortion and maintain the sealing resin 12 in the mold. If an attempt is made to make the flow uniform, the thickness of the upper and lower sealing resins will each be 0.25-0.25 m, whereas the protrusion amount of the wire 10 is 0.2 to 0.3 m as described above. In most cases, there is a problem that the wire 10 is exposed from the surface of the sealing resin 12. In addition, if the thickness of the upper sealing resin is set to 0.31 in an attempt to avoid this, the thickness of the lower sealing resin becomes 0.2 mm, resulting in increased thermal distortion and poor flow of the resin during molding. There was a problem that the quality of the product deteriorated due to uniformity.

The present invention has been made in view of the above points, and provides a resin-sealed semiconductor device that is ultra-thin with a total thickness of 1.2 wm or less, has little thermal distortion, and has good resin moldability. The purpose is to

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a resin-sealed semiconductor device in which the overall thickness of the device is 1.2 mm or less, and a lead frame on which a semiconductor element is mounted. The thickness of the island is less than half that of the other lead frame parts.

[For production]

By reducing the thickness of the island, the thickness of the sealing resin increases by the amount of the decrease, so the range of selection for the balance between the resin thickness above the semiconductor element and the resin thickness below the island increases.

〔Example〕

1 and 2 show an embodiment of a resin-sealed semiconductor device according to the present invention, FIG. 1 is a longitudinal sectional view thereof, and FIG.
a) is a plan view of the lead frame, and Fig. 2) is a plan view of the lead frame.
Figures 3 and 4 in Figure 0, which is the BB sectional view of a).
Components denoted by the same reference numerals as those of the conventional resin-sealed semiconductor device shown in the drawings have the same configurations, so a detailed description thereof will be omitted and will be briefly described below. The lead frame 22 of the semiconductor device 21 is integrally formed with a lead frame frame 3, an island 24 at the center thereof, and a hanging lead 5 connecting these parts, and a semiconductor element 6 is mounted on the island 24 with an adhesive. The semiconductor element 6 is electrically connected to an inner lead 8 integrated with an outer lead 11 electrically connected to an external device by a wire IO. The components such as the semiconductor element 6, including the tip of the inner lead 8, which is the central part of each component assembled in this way, are usually sealed with a semiconductor sealing resin 32 by transfer molding or the like to protect them from the external environment. protected.

In this device, the thickness of the island 24 is less than half the thickness of other parts of the lead frame 2. For example, the thickness of the entire semiconductor device 21 is 1.2111
In this embodiment, the thickness of the semiconductor element 6 is 0.
It is formed into four fins, and the thickness of the island 24 is
1/400 of the thickness of 0.2 m of the lead frame 2 (for example, 42% N1-Fe) whose coefficient of linear expansion is close to that of the semiconductor element 6.
05 m. The thickness of adhesive 7 is 0.05
It is a temple. As a result, the thickness of the sealing resin 32 above the semiconductor element 6 and the thickness below the island 24 are both 0.3.
It becomes 5-. This is the protrusion amount of the wire 10 from 0.2 to 0.
．． Since the wire 10 is larger than the three cabinets, the wire 10 is not exposed from the surface of the sealing resin 32, and the upper and lower thicknesses are balanced, so there is no deformation due to thermal distortion or problems during molding. .

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in a resin-sealed semiconductor device in which the overall thickness of the device is 1.21 mm or less, the thickness of the island of the lead frame on which the semiconductor element is mounted is compared with that of the other lead frame parts. By reducing the thickness to less than half, the thickness of the encapsulating resin increases by this reduction, and the thickness of the encapsulating resin can be increased by reducing the thickness of the encapsulating resin above the semiconductor element and between the islands without exposing the electrical connection wires from the surface of the encapsulating resin. Since it is possible to have the same dimensions as the lower part,
A resin-sealed semiconductor device with a beautiful appearance and high reliability can be obtained without deformation due to thermal distortion or uneven flow during molding of the sealing resin.

[Brief explanation of the drawing]

1 and 2 show an embodiment of a resin-sealed semiconductor device according to the present invention, FIG. 1 is a longitudinal sectional view thereof, and FIG. 2 (a
) is a plan view of the lead frame, and FIG. 2(b) is a plan view of the lead frame.
BB sectional view in a), FIGS. 3 and 4 show a conventional resin-sealed semiconductor device, FIG. 3 is a vertical sectional view thereof, FIG. 4(a) is a plan view of a lead frame, Figure (b) is the fourth
It is AA sectional view of figure (a). 6... Semiconductor element, 21... Resin-sealed semiconductor device, 22... Lead frame, 24... Island, 32... Semiconductor-sealed resin.

Claims (1)

[Claims] A resin-sealed semiconductor device in which the thickness of the entire device is 1.2 mm or less, characterized in that the thickness of the island of the lead frame on which the semiconductor element is mounted is less than half the thickness of the other lead frame parts. type semiconductor device.