JPS58178544A - Lead frame - Google Patents

Abstract

PURPOSE:To obtain a lead frame which can be mounted in a high density by forming with conductive foils when forming circuit element placing parts, mutual wirings and external lead wirings on both front and back surfaces of a flexible insulating plate, opening through holes capable of flowing sealing resin at the plate, and mutually connecting the foils through the holes. CONSTITUTION:A desired mask pattern is formed by a photoetching method in a dual in-line type lead frame by employing as a flexible insulating plate 10 to make a substrate a polyimide film, bonding conductive foils on front and back surfaces. In other words, semiconductor chip plating parts 1, 2, 3, internal mutual wirings 4, 5, external lead wirings 6, 7 and frame 16 are formed on the front and back surfaces of the plate 10. Then, through holes 8, 9 capable of flowing sealing resin are opened at the prescribed positions of the foils of the plate 10, and necessary mutual wirings are formed of fine metal wires. In this manner, an integrated circuit may be contained in a sole sealed enclosure, thereby improving the integration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lead frame having a structure in which a conductive foil is disposed on a flexible insulating plate.

2. Description of the Related Art Lead frames for semiconductor devices are generally formed by punching a metal plate into one piece. With this type of lead frame, when multiple semiconductor chips are mounted independently, it is difficult to set up the mounting part in a state that is lifted from the external lead-out wire, so an extra external lead-out wire is required to support it. Requires lines and the shape is large.)
Another problem is that there is a limit to how many independent semiconductor chips or circuit elements can be incorporated.

On the other hand, when mounting semiconductor integrated circuits, a method is used in which the tips of a large number of metal foil leads arranged on a flexible insulating board are bonded to predetermined connection parts of the semiconductor chip, also known as the so-called film carrier method. widely known. However, although this film carrier method has the advantage that the metal foil leads called finger leads and a large number of bonding pad portions of a semiconductor chip can be formed in a single bonding process, In the case of a hybrid integrated circuit in which a semiconductor chip and other circuit elements are mounted independently or in combination with a semiconductor chip and other circuit elements, bumps (protruding electrodes) are placed at the connection points on the semiconductor chip side and the circuit element side. It is necessary to perform a unique processing called die bonding, which is a traditional assembly technology.
There is a problem with compatibility with wire bonding technology.

The present invention solves all of the above-mentioned problems found in conventional metal plate lead frame or film carrier systems. That is, in the present invention, one
The present invention provides a lead frame in which a mounting part for a circuit element body, a phase and q wiring part, and a main part of an external lead-out line are formed of a conductive foil body.

Next, the present invention will be explained in detail using the drawings.

FIG. 1 shows an embodiment of the present invention, in which dual in-line (D
FIG. 3 is a plan view of an IL) type lead frame.

In the figure, 1, 2.3 are, for example, semiconductor chips,
Or a mounting part for a circuit element body consisting of a passive circuit element, 4
, 6 is an internal interconnection part, 6.7 is an external lead-out wire part, small holes 8 and 9 are through holes, 1° is a flexible insulating plate, 11.1
2.13 is an opening provided in the flexible insulating plate 10, and 14.16 is a feed hole used in the assembly process;
6 is a frame portion. For example, a polyimide film is suitably used for the flexible insulating plate 1o.
Copper foil is pasted on top as a conductive foil to form a layered plate, and this copper foil is processed into a desired mask pattern using a photo-etching technique. 4.6,
A lead frame structure is formed in which the external lead wire portion 6.7 and the frame portion 16 remain. Such conductive foil bodies are provided on both sides of the flexible insulating plate 1o, and the distance between the conductive foil bodies on both sides is 1.
Conductive connections are made through through-holes 8.9, depending on the requirements of the q-way configuration. Note that the external lead wire portions 6.7 are provided on both sides sandwiching the flexible insulating plate 10 in order to maintain strength and improve external connection, and are conductively coupled to each other through the through hole 9. To construct an integrated circuit using this lead frame, first select passive circuit elements such as a predetermined integrated circuit semiconductor chip, a resistor, and a capacitor for each of the mounting parts 1, 2, and 3 of the circuit element body. The electrodes of each of these circuit elements are connected to the force tip of each external lead-out m6.7 and a predetermined interconnection part 4.5 using thin metal wires using a well-known wire bonding technique. If the integrated circuit configuration requires passive circuit elements such as resistors and capacitors in excess of the number of mounting parts, these circuit elements can be placed in the external wiring part 6.7 and interconnection part 4.6. Either one can be selected and connected by soldering, and if connection between each wiring part is required, wire bonding using thin metal wires can also be used. The mutual wiring section 4.5 is a flexible insulating plate 1o.
Since it is attached to the external lead wire section 6゜7, it is placed in a so-called floating state, which is useful for internal wiring of a hybrid integrated circuit configuration, and enables high-density mounting of circuit elements. Not only this, but also by using it as a relay wiring part during wire bonding, it is possible to avoid intermingling of thin metal wire connections. Next, after completing the wiring connections of the integrated circuit configuration, an outer envelope is formed by resin sealing molding. At this time, the openings 11.
12, the resin flows into these openings and wraps both sides of the flexible insulating plate 1o. As a result, the resin-sealed envelope reliably encapsulates the integrated circuit portion, and also improves the bonding properties when covering both sides of the flexible insulating plate 1°, and improves the strength of the envelope. The sealing side surface of the outer envelope of the resin pair I is placed at the position of the chain line connecting the centers of the openings 11 and 12 of the flexible insulating plate 1o, the so-called resin mold line (dashed line in FIG. 1) 17. be done.

The lead frame shown in Figure 1 is used in the actual integrated circuit assembly process in the form of a large number of connected pieces, as shown in Figure 2. In order to adapt to the bonding process and the automatic feeding device in the resin pair f1 process, the feed hole 1
4.15 is used. Then, in the final process, the frame portion 16
is separated to complete a single DIL type hybrid integrated circuit including a semiconductor integrated circuit chip as shown in FIG. The DIL type hybrid integrated circuit device shown in FIG. 3 can be used by directly soldering it to applied equipment using its external lead wire portion 6.7, or by connecting it with connectors. In particular, as can be seen in FIG. 3, the widened portion of the external lead wire portion 6.7 is integrally bonded to the resin envelope 18 side by the flexible insulating plate 1o, so that the outer tip of the external lead wire portion 6.7 is It has sufficient mechanical strength to withstand the work of inserting it into connectors.

The present invention is applicable not only to the DIL type integrated circuit device shown in the embodiments of FIGS. 1 to 3, but also to 7-in-line (SIL) type and flat package type integrated circuit devices. Furthermore, it can be applied to any shape of the outer envelope and the shape of the external lead-out wire, and is essentially a flexible insulating plate.
Furthermore, the mounting portion for the circuit element body, the mutual wiring portion, and the main portions of the external lead-out lines are formed of conductive foil. The lead frame of the present invention includes one in which conductive foil bodies are on both sides of a flexible insulating plate and conductively connected to each other through through holes, and a circuit element body made of conductive foil bodies on a flexible insulating plate. Examples of embodiments include one having a plurality of placing parts and one having an opening in a part of the flexible insulating plate through which molding resin can flow.

According to the present invention, since the flexible insulating plate has a mounting part for a circuit element body made of conductive foil, an interconnection part, and an external lead-out line part, semiconductor chips as integrated circuit elements, various passive Each circuit element can be internally wired and housed within a single encapsulated envelope to achieve high density packaging. In addition, according to the present invention, assembly techniques such as die bonding and wire bonding, as well as transfer mold resin molding and sealing are also possible, and it has excellent compatibility with conventional techniques used in conventional integrated circuit configurations. Therefore, the lead frame of the present invention has great industrial value.

[Brief explanation of the drawing]

FIG. 1 is an enlarged plan view of a lead frame according to an embodiment of the present invention, FIG. 2 is a diagram showing a connected body of lead frames according to an embodiment of the present invention, and FIG. 3 is an integrated circuit according to an embodiment of the present invention. FIG. 3 is a perspective view of the device mounting body. 1.2.3... Placement section for circuit element body, 4.6.
...... Mutual wiring section, 6.7... External lead-out line section, 8.9... Through hole, 10...
Flexible absolute plate, 11° 12.13... Opening part,
14.15... Feed hole, 16... Frame, 17... Resin sealed side surface, 18... Resin envelope. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Scope of Claims] (1) A lead characterized in that it is formed of a circuit element mounting part, an interconnecting wiring part, and an external lead-out line main part p' conductive foil body on a flexible insulating plate. flame. (b) A lead according to claim 1, wherein conductive foil bodies are formed on both sides of the flexible insulating plate, and the conductive foil bodies are electrically connected to each other through through holes. flame. The one-node frame according to claim 1, characterized in that it has a plurality of mounting parts for circuit element bodies. (4) The lead frame according to claim 1, wherein the flexible insulating plate has an opening through which a sealing resin can flow.