KR950002210B1 - Method of mounting a semiconductor chip - Google Patents

Abstract

The method obtains a packaging chip module of high density by stacking chips on an insulating substrate. The method has the steps of; making the first layer by attaching semiconductor chips on the substrate; making the second layer above the first layer by beam-lead. By repeating these steps, multilayers are produced. And the chip pad and the metal line are connected by a metal wire bonding.

Description

Semiconductor chip mounting method

1 is an assembly view illustrating a method of mounting chips in a stack according to the present invention.

1 is a cross-sectional view of a state in which chips are mounted in a stack according to the present invention.

1 is a view of a chip mounted in a stack according to the present invention.

2 is a cross-sectional structural view showing a structure of a beam-lead as a connecting means used in chip mounting.

3 is a cross-sectional view illustrating a state in which chips are successively stacked in a plurality of layers according to the present invention.

The present invention relates to a chip mounting method for mounting chips on a plate such as a printed circuit board, and more particularly to a method for mounting chips in a stack.

Semiconductor integrated circuits are made from wafer processes and each chip is packaged separately. In an IC chip printed circuit board or module having a unique operating function, two-dimensional arrangements are usually performed to form an electronic device by appropriately connecting each terminal. However, in order to increase the mounting density and to mount more compactly, there is an example of forming a single electronic device by mounting chips in a stack type. In the case of reducing the mounting area and increasing the mounting area, such a stack type mounting chip is continuously mounted in the same direction, and a plurality of external terminals derived from each chip are connected, or two chips face each other. There is a mounting method by a so-called mirror chip.

However, in this case, it is inefficient mounting method such as the necessity of mirror chip and two chips. In addition, in the case of single-layer stacking, the wiring connection is complicated and there is a limitation in that there is a limitation without further improvement.

The present invention seeks to provide a chip mounting method that is more flexible and easier to work with.

The semiconductor mounting method according to the present invention is a method of mounting a semiconductor chip on an insulated circuit board on which metal lines are formed, and having a plurality of metal pads on an upper surface and a lower surface thereof. Arranging and arranging at intervals to bond the lower surface of the chip with the substrate to form the chip mounting part of the first layer; Connecting a pad of a chip to the metal line of the substrate and connecting the metal line of the substrate to a pad to be connected to another chip by beam-lead connecting means; The chip is stacked on a substrate by forming a unitary unit stack formed by connecting the upper surface of the chip to be stacked on the chip and the pad of the chip so as to form an integrated unit stack forming body by beam-lead connecting means. .

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is an assembly diagram showing a state in which chips are laminated to each other according to the chip mounting method provided by the present invention.

The chip 1 is separated from the wafer and a metal pad 1A is formed on the chip upper surface 1A with the current pattern. The metal pad 2 is connected to a lead wire to a pad of another chip or to another circuit component. The chip 1 has an upper surface 1A with a pad and a lower surface 1B in the direction toward the substrate. FIG. 1B schematically shows the cross-sectional shape of an example in which chips are mounted in a stacked type on a printed circuit board (PCB) 3 made of an insulating resin, and is firmly attached to the lower side of the chip by using an adhesive 4 on the PCB. The chip mounting portion 5 of the first layer is formed, and then the chip mounting portion 6 of the second layer is stacked and mounted thereon. Therefore, the chip mounting part of the first layer and the chip mounting part of the second layer are integrated to form one unit stacking agent 10.

The PCB includes a chip and a metal line on the surface thereof, and the metal pad on the upper surface of the chip mounting part 5 of the first layer is bonded by the wire 7 to the PCB as shown in FIG. The chips of the chip mounting part 6 of the second layer are connected to each other as shown in FIG.

In FIG. 1A, the chips of the first layer attached with adhesive on the substrate are arranged in a row at appropriate intervals with the chip top face up. The stacked chips of the second layer are turned upside down so that the upper surface of the chip faces the upper surface of the chip located on the first layer, as shown in the drawing. The chips of the first layer and the chips of the second layer are then in the form of pads facing each other, and the necessary connection between these pads is connected by means of a beam-lead 8 in this embodiment. 1C is a view of the PCB as viewed from the top when the connection is mounted as described above.

The PCB comprises a chip 1, a metal line 9 and a through hole (not shown) printed on the surface of the PCB, and other discrete elements, and the pad of the metal line 9 and the chip as shown in FIG. (2) is connected to the gold wire (7) by the method of thermocompression bonding or the like, and the beam-lead (8) connecting the chip to the chip connects the chips and leads extending out of the chip to the metal line (9). It is connected again.

Based on the above description, a method of mounting a chip in a stacked type on a PCB provided by the present invention will be described. First, the necessary through-holes, metal lines or a plurality of passive elements are formed in the PCB.

The lower side of the chips of the first layer is bonded to the substrate using an adhesive on the prepared PCB.

The pad and the metal line on the upper surface of the chip of the first layer are connected by wire or beam lead.

The connecting means here describes the beam-lead in more detail. FIG. 2 is a cross-sectional view of the beam lead, which is different from the wiring connection of the wire 7 by a lead wire having a metal layer 8C interposed between the insulating films 8A and 8B made of polyimide. It is wired in this way.

The beam-lead is inserted between the metal pad and the pad by thermal compression, and the beam-lead out of the chip is connected to the metal line. And the same applies to the beam-lead connection method between the pads on the third or fourth layer.

Subsequently, the chips to be placed on the chips of the first layer are turned upside down so that the pads face each other, and then the beam-lead is connected to each other between the pads of the first layer and the chip pads of the second layer. The connection is securely bonded using a thermocompression or ultrasonic process.

As described above, the chip mounting method according to the present invention is characterized in that a pair of chips face each other and wired by connecting means such as a beam lead. However, wire bonding, TAB, or the like may be used as the connecting means in addition to the beam-lead, but it is suitably employed only in the case of reference numeral 7 of FIG.

3 is a cross-sectional view showing an example of application of the same in the spirit of the present invention, and shows an example in which two or more layers are formed instead of two layers.

In the configuration example of FIG. 1, the redundant body is formed together with one first layer chip and the second layer chips thereon, so that they are stacked in a plurality of layers in one unit.

The unit stack forming agents 10 are laminated with each other by an adhesive material.

However, in the process, the first unit stack forming agent 10 is first laminated and then exposed to form a second unit stack forming agent 10 corresponding to the lower surface of the second layer chip forming chip 11. Glue the bottom surface and glue it to the exposed screen of the second layer chip.

The chips 12 of the fourth layer are laminated in the same manner as the method of forming the first unit stack forming agent 10 thereon.

Thus, a high density chip mounting module can be obtained by forming a plurality of collisions in a stacking direction based on the unit stacking body. Therefore, the mounting area is reduced.

Claims (4)

A method of mounting a semiconductor chip having a plurality of metal pads on an upper surface and a lower surface thereof on an insulated circuit board having metal lines formed thereon, the method comprising: arranging a plurality of chips on the substrate at predetermined intervals. Bonding a plurality of chip lower surfaces and a substrate to form a chip mounting part of a first layer, connecting some pads of the chips and metal lines of the substrate, and pads to be connected to other chips through beam-lead connection means; A method of mounting a semiconductor chip, comprising the steps of forming an integrated unit stack forming body by stacking connection. The semiconductor chip mounting method of claim 1, further comprising stacking one or more unit stacked bodies successively on the basis of the unit stacked bodies. The method of claim 2, wherein the connection between the unit stacking bodies is firmly adhesively connected with an adhesive. The semiconductor chip mounting method according to claim 1, wherein the beam-lead connection means is a connection line having a shape in which a metal layer is interposed between two insulating layers.