JPH0810746B2 - Memory module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a memory module in which two or more memory IC chips are stacked and mounted on an insulating substrate.

[Conventional technology]

Conventionally, as this type of memory module, there is one having a structure as shown in the sectional view of FIG. In the figure,
The insulating substrate 1 is made of glass epoxy, which is generally called a printed circuit board, and has an insulating layer 2 and lead insertion holes 3 formed on the surface thereof. (Dual inline package)
The lead 5 of the semiconductor device 4 referred to as
And so on. For such a memory module, there is a marked tendency for the memory capacity to increase with the increase in the capacity of electronic devices equipped with the memory module, and for the trend toward smaller and thinner memory modules as the electronic devices become smaller and thinner. Improvement of packaging density and thinning of IC semiconductor devices are important issues.

On the other hand, there is a package in which a flat package 7 as shown in FIG. 9 and a chip carrier package 8 as shown in FIG. It is not sufficient for such an ultra-small and thin electronic device.

As the memory module for memory cards, the 11th
As shown in the figure, the memory IC chip 10 is bonded to the insulating substrate 1 on which the wiring layer 2, the bonding pads 9 and the like are formed.
There is one in which the electrodes are fixed by 11, and the electrodes of the memory IC chip 10 and the bonding pads 9 are connected by bonding wires 12 and sealed by a sealing resin 13. With such a structure, the packaging density can be improved and the thickness can be reduced as compared with the conventional method.

[Problems to be solved by the invention]

The conventional memory module described above is the semiconductor device 4
Alternatively, since the memory IC chip 10 is mounted in a plane, there is a limit to the improvement in mounting density. Especially for memory modules for memory cards, the number of semiconductor devices or memory IC chips that can be mounted is limited because the outer shape of the memory card is limited to the normal cash card size. There is also a limit to the memory capacity of.

On the other hand, for example, there is one in which two DIP semiconductor devices are vertically stacked and three-dimensionally mounted so that the occupied area of each device is halved. However, it has a drawback that it cannot be applied to an ultra-thin electronic device having a maximum thickness of about 3 to 5 mm, such as a memory card.

An object of the present invention is to provide a memory module in which a memory IC chip is mounted on an insulating substrate by stacking the memory IC chips in two or more stages by a film carrier method to achieve high packaging density and thinning.

[Means for solving problems]

In the memory module of the present invention, the insulating substrate and the leads are connected to the electrodes formed on the one main surface, and the coating resin is formed on the one main surface so as to cover both the electrodes and the leads. Two film carrier type memory IC chips, one memory
The other main surface of the other memory IC chip is adhered and stacked on the one main surface of the IC chip, and the one memory
The other main surface of the IC chip or the one main surface of the other memory IC chip has two film carrier type memory IC chips fixed to the insulating substrate.

Preferably, a resin dam formed on the insulating substrate and surrounding the two film carrier type memory IC chips, and a space surrounded by the resin dam are filled, and the two film carrier type memory IC chips are filled. It is characterized by further including a sealing resin that integrally covers.

Preferably, the two film carrier type memory IC chips each have a chip select terminal and another terminal, and the other terminal is commonly connected to a terminal on the insulating substrate through the lead. The chip select terminals are individually connected to the individual terminals on the insulating substrate via the leads.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a partial sectional view showing an embodiment of the present invention, and FIG.
Figures and 4 are plan views showing two arrangements of IC chips on a carrier tape, and Figures 3 and 5 are ICs of Figures 2 and 4.
FIG. 6 is a plan view showing the shape of the chip, and FIG. 6 is a plan view in which this embodiment is arranged on a substrate. In Figure 1, memory IC
The chips 10 and 10 'are mounted on an insulating substrate 14 for a memory module in a two-tiered structure with an adhesive 11. In these memory IC chips 10 and 10 ', the electrodes of the memory IC chip and the bonding pads 9 of the insulating substrate 14 are lead-bonded by the leads 15 by the film carrier method. Also, each memory IC
A coating resin 16 is coated on the chips 10 and 10 ', and a sealing resin 13 seals the memory IC chip so as to cover the entire memory IC chip.

The structure of the memory module having such a structure is performed as follows.

First, as shown in FIGS. 2 and 4, the sprocket hole 17 for carrying and positioning, and the memory IC chip 1
A film carrier tape 20 in which a metal foil made of copper or the like is adhered to an insulating film having a device hole 18 into which 0 and 10 'are inserted, and leads 15 and an electric selection pad 19 having a desired shape are formed by etching or the like. , 20 'and memory with bumps 21 which are metal protrusions previously provided on the electrode terminals
IC chips 10 and 10 'are prepared, and then leads 15 of the film carrier tape and bumps 21 of the memory IC chip are subjected to inner lead bonding by a thermocompression bonding method or a eutectic method, and electrically selected in the state of the film carrier tape. A contactor is brought into contact with the pad 19 for use in electric selection. Then, as shown in FIGS. 3 and 5, the leads 15 of the film carrier tape are cut to a desired length and molded.

Here the leads 15 of the film carrier tape 20, 20 '
Among them, at least the chip select terminal leads 22 and 2 that are bonded to the chip select terminals of the memory IC chip
As for 2 ', as shown in FIGS. 2 and 4, when the memory IC chips are stacked in two stages, the outer lead bonding positions are different for the upper and lower layers, and the film carrier tape is formed on the upper layer. It is necessary to prepare two types, one for the upper and one for the lower stage. Also, the position and shape of the lead cutting and molding must be set separately for the upper and lower stages according to the height of the memory IC chip and the position for outer lead bonding. is necessary.

However, for the electric sorting pad 19, if the film carrier tapes for the upper stage and the lower stage are in a common position,
The electric sorting device can be standardized.

Next, as shown in FIGS. 1 and 6, an insulating substrate 14 having a wiring layer 2 and a bonding pad 9 is prepared,
The memory IC chip 20 after the lead cutting and molding is fixed on the insulating substrate with the adhesive 11 such as silver paste, and the leads 15 and 22 are outer lead bonded to the bonding pad 9. Further, similarly, the memory IC chip 20 'is fixed with the adhesive 11 on the memory IC chip 20 previously fixed,
The leads 15 and 22 'are bonded to the bonding pad 9 by the outer lead bonding.

Next, after fixing the resin dam 23, the entire memory IC chips 20, 20 'are covered and sealed with the sealing resin 13 to complete the memory module.

Of the bonding pads 9 of the insulating substrate 14, the bonding pads 9 corresponding to the chip select terminal leads 22 and 22 'are aligned with the chip select terminal lead positions as shown in FIG. It is also necessary to provide them electrically separately. Also leads 15,22,
To prevent the 22 'from short-circuiting with the periphery of the memory IC chips 10, 10', to protect the surface of the lower memory chip IC and to improve the moisture resistance of the memory IC chip.
As shown in the figure, it is necessary to coat the coating resin 16 so as to fill the surface of the memory IC chip and the space between the lead and the edge of the memory IC chip. This resin coating can be performed from the inner lead bonding step to the outer lead bonding step, but the workability is better if it is applied in the state of the film carrier tape before the lead cutting step.

FIG. 7 is a vertical sectional view of the second embodiment of the present invention. Also in this embodiment, the memory IC chips 10 and 10 'are mounted on the insulating substrate in two layers by the adhesive 11 and face down with the surface of the memory IC chip facing down. These memory IC chips 10 and 10 'are lead-bonded by the leads 15 to the electrodes of the memory IC chip and the bonding pads 9 of the insulating substrate 14 by the film carrier method. In addition, each memory IC chip 10,10 '
Coating resin 16 is coated on the top,
Sealing resin 13 to cover the entire memory IC chip
Encapsulates the memory IC chip.

The manufacturing of the memory module having such a structure is the first except that the memory IC chip is mounted face down.
It can be carried out in the same manner as the embodiment of

In this embodiment, since the memory IC chip is mounted face down, the molding amount of the lead 15 may be small, and as a result, the distance between the edge of the memory IC chip and the bonding pad 9 can be shortened. The density can be improved.

Although the memory IC chips are stacked in two steps in this embodiment, the same operation can be performed in three or more steps. If the exterior part of the memory module is made rigid, the resin 13 covering the memory IC chip can be omitted.

Furthermore, the lower memory IC chip 10 is mounted face down with the memory IC chip surface facing down on the insulating substrate 14, and the upper memory IC chip 10 'is mounted face up with the memory IC chip surface facing up. It is also possible to implement by alternating the memory IC chip surface like the above method, but in this case, since the upper and lower terminal positions are different for all terminals of the memory IC chip, the It is necessary to independently provide the bonding pad and the lead of the film carrier tape at each terminal.

〔The invention's effect〕

As described above, according to the present invention, by mounting the memory IC chips in two or more stages and performing the lead bonding by the film carrier method, the mounting density of the memory IC chips can be improved and the memory module can be thinned. It is possible to provide a memory module compatible with a large capacity memory card.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a memory module according to a first embodiment of the present invention, FIGS. 2 and 4 are plan views showing two arrangements of the carrier tapes of FIG. 1, FIG. 3, and FIG. Is Fig. 2,
FIG. 4 is a plan view showing the shape of the IC chip of FIG. 4, FIG. 6 is a plan view of the present embodiment arranged on a substrate, and FIG. 7 is a sectional view of the second embodiment of the present invention. FIG. 11 is a sectional view of two examples of a conventional memory module, and FIGS. 9 and 10 are perspective views of two examples of a general semiconductor device. 1 ... Insulating substrate, 2 ... Wiring layer, 3 ... Lead insertion hole, 4 ... DIP semiconductor device, 5 ... Semiconductor device lead, 6 ... Solder, 7 ... Flat package, 8 ... Chip Carrier package, 9,9 '... bonding pad, 10,10' ... memory IC chip, 11 ... adhesive, 12
...... Bonding wire, 13 …… Sealant resin, 14 ……
Module substrate, 15 ... Lead, 16 ... Coating resin, 17 ... Sprocket hole, 18 ... Device hole, 19 ... Electrical selection pad, 20,20 '... Film carrier tape, 21 ... Bump, 22 , 22 '... Lead for chip select terminal, 23 ... resin dam.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01L 25/18

Claims (3)

[Claims] 1. An insulating substrate, and a lead is connected to an electrode formed on one main surface of the insulating substrate, and a coating resin is formed on the one main surface so as to cover both the electrode and the lead. One film carrier type memory IC
A memory IC chip, the other main surface of the other memory IC chip is adhered and laminated on the one main surface of the one memory IC chip, and the other main surface of the one memory IC chip or the other memory IC chip A memory module having two film carrier type memory IC chips, the one main surface of which is fixed to the insulating substrate. 2. A memory IC of two film carrier type, which is formed on the insulating substrate and which fills a resin dam surrounding the two film carrier type memory IC chips and a space surrounded by the resin dam.
The memory module according to claim 1, further comprising a sealing resin that integrally covers the chip. 3. The two film carrier type memory IC chips each have a chip select terminal and another terminal, and the other terminal is commonly connected to a terminal on the insulating substrate through the lead. 3. The memory module according to claim 1, wherein the memory cell module is connected, and the chip select terminals are individually connected to individual terminals on the insulating substrate via the leads.