JPS5845820B2 - hand tai souchi no seizou houhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for manufacturing a semiconductor device, and more specifically, a method for easily manufacturing semiconductor pellets with beam leads.

Conventionally, beam leads for connecting electrodes formed on semiconductor pellets have been formed as a final manufacturing process for single crystal substrates (hereinafter referred to as wafers) containing a large number of semiconductor pellets on which circuit elements are formed.

FIG. 1 shows a part of the wafer.

Lla, lb are conductor wirings to each circuit element in the semiconductor pellet 10, 2, 2a, 2b are beam leads 12 of the semiconductor pellet 10; 12a are beam leads of the adjacent semiconductor pellet 20; 3, 3a, 3b, 13, 13a is an electrode portion, and 4 is a divided region of the semiconductor pellet.

In such cases, the formation of beam leads must be taken into account already at the stage of integrated circuit design.

That is, the beams 2.2a, 2b and 12, 12a must be arranged so that they do not come into contact with each other.

Therefore, the distance between adjacent electrodes 3 and 38 in the same pellet had to be taken into consideration.

Furthermore, when dividing the pellets, the usual methods using a diamond tool, a grindstone, or a laser cannot be used, and mesa etching must be performed from the back side.

Therefore, the divided area 4 also required a thickness of about 100μ compared to the usual 50μ.

Furthermore, since the length of the beam is limited by the divided regions 4, it was necessary to take this aspect into consideration.

SUMMARY OF THE INVENTION Therefore, the present invention provides a method for manufacturing a chip with beam leads that solves the above-mentioned conventional drawbacks such as consideration at the design stage and reduction in the total number due to the necessity of widening the divided area. be.

First, the method for manufacturing semiconductor pellets used in the present invention will be described in a second manner.
This will be explained with figures.

FIG. 2A shows a silicon wafer, and 21 is a silicon substrate of one conductivity type, which has island regions 22 and 23 in which regions such as transistors and diodes (not shown) are formed.

24 is an island region for cutting, and 25 is a silicon oxide film formed on the surface of the substrate 21.

A dashed line 26 indicates a position to be cut, and the wafer is cut and divided at this portion.

In this state, a portion of the oxide film 25 is removed to form contact windows 27 and 28 for forming electrode wiring between each circuit element, and at the same time, a portion of the oxide film 25 is removed to provide a cutting region 29.

This region 29 may be as wide as necessary to completely remove a portion of the oxide film 25 and may be equal to the width of the contact window 27, 28 (B).

Next, as shown in C, Al electrode wirings 30 and 31 are formed.

After this, from the other main surface different from the main surface on which the electrode wiring is formed, a grindstone is used to cut the oxide film 25 on the silicon wafer in a width of 50 to 100 μm at a place corresponding to the cutting area 29.
(D).

Thereafter, the surface on which the Al electrode wiring is formed is sufficiently protected with Abinisine wax (trade name) or the like, and etched with an HF:HNO3 based etching solution.

If an etching solution of HNO3:HF=10:1 is used, the recess 33 can be formed, and the wafer can be divided leaving enough parts 25a and 25b of the oxide film 25 on the surface, and the separated semiconductor pellets can be separated by 40°. You can get 50.

A method according to an embodiment of the present invention for forming a beam lead on the semiconductor pellet produced as described above will be explained with reference to FIG.

In FIG. 3A, 50 is the aforementioned semiconductor pellet, 51
is an insulating film formed on the surface of the pellet 50,
It is made of a heat-resistant resin film, a silicon oxide film, a silicon nitride film, or the like.

52 is an adhesive for temporarily fixing the temporary fixing substrate 53 and the pellet 50 together.

54 is a part of the electrode wiring on the pellet 30.

In the case of FIG. 3A, only one semiconductor pellet 50 is shown, but of course two or more semiconductor pellets can be arranged and temporarily fixed in the same manner.

However, when arranging two or more semiconductor pellets, it is necessary to make the interval between them wider than in the wafer state, and to widen the length of the beam lead sufficiently.

After that, as shown in B, the periphery of the semiconductor pellet 50 is coated with the oxide film 25, insulating film 5, etc. using styrene resin, wax, etc.
1. Fill with a substance 55 that can be easily removed with a solvent that does not react with the substrate 21.

Thereafter, the temporary fixing board 53 is removed.

C shows the temporary fixing substrate 53 and adhesive 52 removed.

The surfaces of the substance 35 and the pellet form the same continuous surface.

Next, as shown in D, a metal thin film 56 is deposited on the entire surface.

When the wiring 54 is made of Al, the thin film 56 preferably has a two-layer structure of Cr+Cu.

Next, E shows a state in which a portion 57 corresponding to a beam is formed by photoetching, and then a metal layer 58 is deposited by electroless plating for reinforcement.

Electroless plating of Au was used as the metal layer 58 for ease of bonding.

Finally, when the buried material 55 is removed as shown in F, a beam lead 60 is created.

The characteristics of the chip with beam leads formed in this way are as shown in F.
0 is an oxide film 25 that is an insulating material that protrudes from the pellet.
It is completely insulated by the b1 insulating film 51.

As described above, the manufacturing method of the present invention (1) does not require consideration of the electrode position on the pellet during design.

That is, after being divided into pellets, they are embedded in a buried material to form a beam, so that a normal wire bonding element can be used.

(2) Since the direction and length of the beam can be freely determined when forming the beam, there is great freedom when designing the board for honding.

etc., have excellent industrial value.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a part of a wafer on which beam leads have been formed by the conventional method, FIGS. 2A to 2E are manufacturing process diagrams of semiconductor pellets used in the present invention, and FIGS. FIG. 3 is a process diagram of a beam lead forming method according to an example. 21...Silicon substrate, 25.25a, 25
b...Silicon oxide film, 40, 50...
・Semiconductor pellet, 51... Insulating film, 54...
... Electrode wiring, 55 ... Buried material, 56.
...Metal thin film, 58...Metal layer, 60.
...beam lead.

Claims (1)

[Claims] 1. A semiconductor pellet having a structure in which a circuit element is configured on the main surface and an insulating coating on the main surface protrudes outward from the periphery, and the spacing between each pellet is set to a predetermined distance from that in the wafer state. A step of spreading and adhering its main surface to a temporary fixing substrate, a step of reinforcing the pellet from the back side using a reinforcing resin, a step of removing the temporary fixing substrate, and a step of extending from an electrode on the semiconductor pellet onto the reinforcing resin. A method for manufacturing a semiconductor device, comprising the steps of forming a beam lead and removing the reinforcing resin.