JPS63207161A - Manufacture of resin sealed type semiconductor device - Google Patents

Abstract

PURPOSE:To improve the effect of heat dissipation at low cost by exposing a reinforcing body outside a sealing resin layer. CONSTITUTION:A technique in which reinforcing bands, tie bars 3, tying the opposed frame bodies of a lead frame 1 for DIP (Dual In-line Package) are exposed outside a sealing resin layer 10 into which a semiconductor element 8 is buried. Consequently, the fabrication of the reinforcing bands 3 is executed at the same time as lead machining in a Cut and Bend process in the final process of the lead frame 1 utilized for the assembly process of the semiconductor element 8, and the reinforcing bands 3 which have been discarded in the Cut and Bend process are applied. Accordingly, the effect of heat dissipation can be improved at low cost without increasing manhours.

Description

DETAILED DESCRIPTION OF THE INVENTION <Object of the Invention> (Industrial Field of Application) The present invention relates to an improvement in a radiation fin integrated with a lead frame in a resin-sealed semiconductor device.

(Prior art) The use of lead frames has been widely used in the assembly process of semiconductor elements, and these lead frames are also used in SIP (Singing), which is mainly used for individual semiconductor elements.
LE In1ine Package) type, and D type, which targets devices with a large number of pins such as integrated circuit elements.
IP (Dual Inline Package) type and so-called gassho type are known. These lead frames are made of conductive metals such as AQ, Cu,
A plate made of Fe or an alloy thereof is formed by a pressing or etching process, and is used to perform a semiconductor device assembly process. On the other hand, effective heat dissipation is attracting attention as semiconductor elements generate more heat as they become more sophisticated, and various improvements have been made to lead frames. JP-A-55-133558 discloses a semiconductor IC using a ceramic DIP package.
A technique has been disclosed in which a cooling piece is provided that extends from the chip connector to the outside via a heat conductor, and the heat conductor of the sealing portion is further provided with holes to improve the heat dissipation effect and airtightness.

The lead frame applied to this technology is explained with reference to Figure 4. This drawing shows a lead frame that has been processed to some extent, and since it is written for a single semiconductor element, its longitudinal direction is not obvious at first glance. Although not, it is presumed to be in the longitudinal direction of the cooling piece 23 extending outside. Therefore, this lead frame is shaped into a very special shape, and a method is adopted in which an opening 22 is provided in the heat conductor 21 to which the cooling piece 23 is connected.

When this is compared with the standard type DIP lead frame shown in FIG. 1, the difference becomes clear.

That is, in this DIP lead frame, in order to construct the unit bodies 4 by dividing the opposing frames 2, 2 at equal intervals, each unit body is divided in the direction perpendicular to the frames 2, 2. A reinforcing band (so-called tie bar) 3 is provided on each of the unit bodies 4, and a conductor 6 connected to the reinforcing band 3 is provided on the bed portion 5 disposed at the center of the unit body 4. Furthermore, this reinforcement band 3
A lead terminal 7 whose free end is near the bed section with the starting point at
form.

Comparing this lead frame with the one shown in FIG. 4, it is clear that the longitudinal direction of the cooling piece 23 is along the frame body 31 in FIG. 3, and as mentioned above, it is extremely It has a special shape.

(Problems to be Solved by the Invention) If a heat dissipation fin is formed on a semiconductor element using the lead frame shown in FIG. 2, it will definitely become extremely expensive. The reinforcing bands, sometimes called tie bars, and the conductors connecting the bed parts are cut a of the lead terminals following the resin sealing process of the semiconductor element.
After the nd bend process, it is discarded as the remaining part of the frame, which is not preferable in terms of material efficiency.

The object of the present invention is to provide a novel method for manufacturing a resin-sealed semiconductor device that overcomes the above-mentioned difficulties, and in particular achieves an increase in the heat dissipation effect using inexpensive means.

<Structure of the Invention> (Means for Solving the Problems) In order to achieve this object, reinforcing bands, so-called tie bars, connecting the opposing frames of the DIP lead frame are made of a sealing resin in which semiconductor elements are embedded. Adopt a method that exposes outside the layer.

(Function) As described above, the reinforcing band forming process of the present invention is carried out at the same time as the lead processing performed in the cut and bend process of the final process of the lead frame used in the assembly process of semiconductor elements. Since the reinforcing band that was discarded in the bending process is utilized, the advantage can be achieved at low cost without increasing the number of man-hours.

(Example) The present invention will be described in detail with reference to FIGS. 1 to 3. Although there are some descriptions that overlap with the description in the conventional technology column for convenience, new numbers will be used to explain them.

FIG. 1A is a perspective view of a resin-sealed semiconductor device completed by applying the method of the present invention, and the opening in FIG. 1 shows a rear view of this FIG. 1A. Figure 3 shows a top view of the lead frame used for this purpose.

This lead frame 1 is for a standard type DIP, and a reinforcing band 3 orthogonal to each other is installed between opposing frames 2 to form a unit body 4 having the same area. A bed portion 5 on which a semiconductor element is mounted approximately in the center is constructed by conductors 6 connected to the reinforcing bands 3.

Since this lead frame is formed from a plate made of AQ, Fe, Cu, and metal alloys using a pressing process or an etching process, it is naturally made of conductive metal.

Lead terminals 7 having free ends located near the bed portion 5 and narrower in width than the conductor are provided on the reinforcing bands 3 to function as external leads of the semiconductor device after a sealing process to be described later.

In this way, each unit body 4... has a reinforcing band 3..., a bed portion 5, a lead terminal 7, and a bed portion 5 having the same dimensions and shape.
. . . and conductors 6, 6 are formed, and although not shown, the frames 2, 2 are provided with openings that are used during conveyance over this lead frame.

By the way, as mentioned above, after die bonding a predetermined semiconductor element 8 to the bed part 5, electrical connections are made by bridging the lead terminals 7 and the electrodes formed on the semiconductor element with thin metal wires 9. After this, the semiconductor element 8, thin metal wires 9, etc., the bed portion 5, etc. are embedded in the sealing resin layer 10 (FIGS. 1 and 2) using a transfer molding method.

Next, the process proceeds to a cut and bend step according to a conventional method.

Conventionally, through this process, the parts exposed from the sealing resin layer 10, such as the frames 2, 2, reinforcing bands 3, etc., are cut, and each lead terminal 7, which becomes an external terminal, is shaped into a predetermined shape. do.

In the method of the present invention, in order to use the conductor 6 and reinforcing bands 3 as they are, they are cut from the frame 2... and the reinforcing bands 3 are sealed with resin as shown in FIGS. 1 and 2. The back side of the layer 10 (the opening in Figure 2) or the sealing resin layer 1 as shown in Figure 3.
It is exposed in the direction along the flat surface of 0 and functions as a heat radiation fin.

<Effects of the Invention> In the method of the present invention, in the so-called cut and bend process near the end of the semiconductor device assembly process, tie bars or reinforcing bands and wide conductors, which were waste products from lead frames, are formed. It has the function of a heat dissipation fin, and can save space at an extremely low cost.

[Brief explanation of the drawing]

FIG. 1A is a perspective view of a resin-sealed semiconductor device to which the method of the present invention is applied; FIG.
3 is a front view of a standard lead frame, and FIG. 4 is a perspective view of a conventional lead frame with radiation fins.

Claims (1)

[Claims] A unit body is formed by dividing opposing frames, and a reinforcing band is provided perpendicular to the frame body of each unit body, and a conductor is provided between the bed part disposed approximately in the center of this unit body and the reinforcing band. A lead terminal is formed continuously on the reinforcing band and has a free end near the bed portion, and the semiconductor element electrode die-bonded to the bed portion and the lead terminal are bridged with a thin metal wire. 1. A method of manufacturing a resin-sealed semiconductor device in which an element and a thin metal wire are embedded in a resin-sealing layer, the reinforcing body being exposed outside the resin-sealing layer.