JPH0322056B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a chip mounting method for mounting chips such as semiconductor devices on a film carrier.

Conventionally, in this type of chip mounting method, for example, as shown in FIG. A plurality of metal leads 2a are provided protruding into the hole 1a, and each of the metal leads 2a has a metal protrusion 4 at its tip.
Each corresponding electrode terminal 6 of the chip 5...
... were brought into contact with each other, and the chips 5 were mounted on the film carrier 3 by heating and pressurizing them with the bonding tool 7 inserted into the device hole 1a. However, as shown in Fig. 4, when the length of the metal lead 2a is 2 mm or more, the metal lead 2a becomes easy to bend and the positioning accuracy becomes poor. It was difficult to maintain, and it was difficult to join it to a mating member such as a circuit board, and sometimes it was cut at the base a.

Therefore, some conventional chip mounting methods include
As shown in the figure, a support ring 9 supported by support bars 8 is provided, and the rectangular frame-shaped support ring 9 prevents the metal leads 2a from bending or coming apart. be.

Problems that the invention seeks to solve However, in recent years there has been an extremely high demand for miniaturization.
When such a support ring 9 was provided, there was a problem that the request could not be met. In other words, since the support bar 8... and support ring 9 parts are formed by punching with a press, the width should be set to 0.5.
It was difficult to do the following in production. Furthermore, if the width was made too narrow, the adhesive layer thereon would fall off, making it difficult to fix the metal leads 2a.

Therefore, the purpose of the present invention is to solve such problems in the method of mounting chips on a film carrier, fully meet the recent demand for miniaturization, and prevent metal leads from bending or coming apart. The purpose is to do so.

Means for Solving the Problems Therefore, in the method of mounting chips on a film carrier according to the present invention, for example, as in the embodiment shown in FIG. A metal foil 12 is applied through the metal foil 11, and then a photosensitive layer 14 is formed on the back surface of the metal foil 12 in each device hole 10a, and the photosensitive layer 14 is exposed and developed to form a support ring 14a. A photoresist 16 is applied to the surface of the metal foil 12, exposed, developed, and then etched to form the support ring 1.
A plurality of metal leads 12a connected by 4a are formed to protrude into each device hole 10a, the surface is plated, and finally the metal leads 12a are
It is characterized in that the chip 19 is bonded to the film carrier 13 by bonding electrode terminals 20 to the ends of each of the chips.

Function: Then, a thin support ring 14a is formed,
Each metal lead 12a with its support ring 14a
It connects and supports...

Embodiment Hereinafter, the present invention will be specifically and detailedly explained according to an embodiment shown in FIG.

In the chip mounting method according to the present invention, first,
As shown in FIG. A, a plurality of device holes 10a are formed at predetermined intervals in a film substrate 10 made of polyimide resin or the like.

Then, as shown in FIG. 1B, a metal foil 12 such as copper foil is attached to the surface of the film substrate 10 via an adhesive 11 to form a film carrier 13.

Next, as shown in FIG. 1C, a photosensitive layer 14 is formed on the back surface of the metal foil 12 in each device hole 10a. The photosensitive layer 14 is made by coating, for example, photosensitive polyimide.

Thereafter, as shown in FIG. 1D, the photosensitive layer 1
4 is masked in an arbitrary shape and exposed with a light source 15.

Then, as shown in FIG. 1E, it is developed to form a support ring 14a in the shape of a rectangular frame, for example. At this time, support bars may or may not be formed at the same time.

Next, as shown in FIG. 1F, a photoresist 16 is applied to the surface of the metal foil 12.

Then, as shown in FIG. 1G, the photosensitive resist 16 is exposed with a light source 17.

After developing as shown in Fig. 1H,
After etching as shown by I, the surface is plated to form a plurality of metal leads 12a projecting into the device hole 10a.

Next, in a separate process not shown, metal protrusions 18 such as Au bumps are formed at the tips of the metal leads 12a.

After that, finally, as shown in FIG. 1J, the corresponding electrode terminals 20... of the chip 19 inserted into the device hole 10a are attached to the metal protrusions 18...
. . , are brought into contact with each other and bonded by heat and pressure using a bonding tool 21, and the chip 19 is mounted on the film carrier 13.

After mounting the chip 19 in this manner, each chip 19 is cut out in a known manner to cut out a chip 19 extending a plurality of metal leads 12a as shown in FIG.
The tips of a... are joined and attached to a mating member 22 such as a circuit board. At this time, support ring 14
If lead a is formed at a position overlapping with chip 19, each metal lead 12a... and chip 1
9 can be prevented from electrically edging.

In the embodiment described above, the chip 19 is mounted on the film carrier 13 by applying heat and pressure using the bonding tool 21. However, it goes without saying that the chip 19 may also be mounted on the film carrier 13 by applying heat with a laser beam for bonding.

Effects of the Invention Therefore, according to the present invention, since each metal lead is connected by a support ring, it is possible to prevent each metal lead from bending or coming apart, and to hold them in alignment. Enables accurate bonding.

In addition, since the support ring is made using a physical and chemical method rather than mechanically, the width can be made thinner, making it possible to fully meet the demands for miniaturization.

Furthermore, since this support ring is not attached using adhesive, it has increased heat resistance.
It becomes possible to attach it close to the chip.

[Brief explanation of drawings]

FIG. 1 is a process diagram showing a chip mounting method according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing how each chip mounted by the chip mounting method is attached to a mating member. FIG. 3 is an explanatory diagram illustrating a conventional chip mounting method. Fourth
The figure is an explanatory cross-sectional view for explaining the metal lead. FIG. 5 is an explanatory perspective view showing another conventional chip mounting method. 10...Film substrate, 10a...Device hole, 11...Adhesive, 12...Metal foil, 12a...
...Metal lead, 13...Film carrier, 14
...Photosensitive layer, 14a...Support ring, 16...
...photosensitive resist, 19...chip, 20...electrode terminal.

Claims (1)

[Claims] 1. A metal foil is attached to the surface of a film substrate with a device hole through an adhesive, and then a photosensitive layer is formed on the back side of the metal foil inside the device hole, and the photosensitive layer is exposed and developed to provide support. A ring is made, and then a photoresist is applied to the surface of the metal foil, exposed and developed, and then etched to form a plurality of metal leads protruding into the device hole and connected by the support ring, and the surface is plated. Then, finally, electrode terminals are bonded to each tip of the metal leads and the chip is bonded to the film carrier.