JPH0653383A - Manufacture of substrate for mounting semiconductor element - Google Patents

Abstract

PURPOSE:To provide a manufacture of a substrate for mounting a semiconductor element in which a conductor layer formed on the surface and a base material have a strong bonding and a thin thickness can be obtained and a heat dissipation of the semiconductor element can be improved. CONSTITUTION:While forming pilot holes 11 on the side of a thin plate material 10, a rectangular base material 14 surrounded by transparent holes 13 for separation whose internal and external parts are partially connected through a plurality of connecting pieces 12 is formed inside the pilot holes 11, and an insulating adhesive 16 is applied to a specific region on the base material 14, and a metal powder 17 is spread to secure before the adhesive 16 hardens. Next, a plating is performed on the spread metal powder 17 and a conductor layer 18 is formed. Further, after covering the whole with a resist film, a predetermined lead pattern is exposed and developed on the conductor layer 18 by a photolithography, and then the conductor layer 18 is formed on a lead pattern 19 by an etching treatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor element mounting substrate on which an electronic functional element having a specific function is mounted.

[0002]

2. Description of the Related Art A lead frame used in a conventional semiconductor device has an element mounting portion for mounting a semiconductor element in a central portion,
A plurality of inner leads radially formed around the element mounting portion and outer leads connected to the inner leads, and after mounting a semiconductor element on the element mounting portion, a pad of the semiconductor element; The inner lead was connected via a metal wire and the outer periphery was resin-sealed. However, in such a lead frame, due to the recent trend toward higher integration, multifunctionality and miniaturization of semiconductor devices, Various problems have arisen as described in. That is, in the conventional semiconductor device, when the degree of integration of the semiconductor element is further increased and the number of inner leads is increased due to the connection, the tips of the inner leads are arranged near the semiconductor element or the inner leads and the semiconductor element are connected to each other. It is necessary to open the space between the element and the metal wire to extend the length of the wire, but if the distance between the inner lead and the semiconductor element is reduced, it is necessary to make the tip of the inner lead thinner, which makes processing difficult. Becomes
Furthermore, if the distance between the inner lead and the semiconductor element is increased, the length of the metal wire becomes longer, and there is a problem that an unexpected short circuit occurs due to contact between adjacent metal wires during transportation or molding. Therefore, in the case of manufacturing only a semiconductor element mounting substrate having a semiconductor element mounting portion and an inner lead portion around the semiconductor element mounting portion, a lead pattern is formed by etching a metal foil adhered on an insulating resin, and then manufactured. There has been proposed a semiconductor device in which an outer lead is joined and resin-sealed at the time of assembly.

[0003]

However, in the above semiconductor device, the inner leads and the like are formed by etching the base material in which the metal foil is adhered on the insulating resin. There is a problem that the metal foil is easily peeled off. Further, since the insulating resin has a certain thickness, it is difficult to reduce the thickness of the semiconductor device as a whole, and the heat dissipation of the semiconductor element is poor. The present invention has been made in view of the above circumstances, and is for mounting a semiconductor element in which the conductor layer formed on the surface and the base material are firmly bonded to each other, can be made thinner, and can also improve the heat dissipation of the semiconductor element. It is an object to provide a method for manufacturing a substrate.

[0004]

A method according to the above-mentioned object.
According to the method for manufacturing a semiconductor element mounting substrate described above, a pilot hole is formed in a side portion of a thin strip material, and a pilot hole is formed in the inside thereof, and is surrounded by a separating through hole whose inside and outside are partially connected by a plurality of connecting pieces. A rectangular base material is formed, an insulating adhesive is applied to a specific area on the base material, and a metal powder is further sprayed and fixed inside the adhesive which is uncured, and then the sprayed metal powder. The conductor layer is formed by plating on the conductor layer, and the entire surface is covered with a resist film. Then, a predetermined lead pattern is exposed and developed on the conductor layer by a photographic method, and then the conductor layer is lead by an etching process. It is configured to be formed in a pattern. Here, it is preferable to use a copper plate or a copper alloy plate for the thin strip material, but the present invention can be applied to other metal plates. Further, it is preferable to perform copper powder and copper plating on the metal powder and plating, but the present invention is applicable to any metal powder or metal plating (eg, nickel powder or nickel plating) that can be etched. Further, it is possible to provide a V notch on the connecting piece.

[0005]

According to the method of manufacturing a substrate for mounting a semiconductor element according to claim 1, a parrot hole is provided on a side portion of the thin strip material and is partially connected to the inside by a connecting piece, but is surrounded by a separating through hole. A square base material is formed, an adhesive is applied on top of this, and metal powder is sprayed and fixed inside the adhesive, and then plating is performed. A conductor layer can be formed by plating with metal powder. Next, after covering the whole with a resist film, a predetermined lead pattern is exposed and developed by a photographic method, and the lead pattern is formed by an etching process, so that a fine portion of the lead pattern can be reproduced. As a result, it is possible to form a higher-density pattern closer to the semiconductor, and further, it is possible to prevent peeling of the formed lead pattern. Since the semiconductor element mounting substrate has the semiconductor element mounted in the center of the thin metal strip material, the heat generated by the semiconductor element is dissipated through the base material. Further, in mounting and wiring the semiconductor element, since the work can be performed while accurately positioning the thin strip material with reference to the pilot hole provided on the side surface of the thin strip material, accurate wiring can be performed. It will be possible.

[0006]

Embodiments of the present invention will now be described with reference to the accompanying drawings to provide an understanding of the present invention. 1 is a plan view showing the steps of a method for manufacturing a semiconductor element mounting substrate according to an embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is an enlarged view of the same portion, and FIG. FIG. 7 is a plan view of a semiconductor element mounting substrate manufactured by another embodiment method.

As shown in FIGS. 1 (A) and 2 (A),
A predetermined pilot hole 11 is formed in a thin strip material 10 made of copper or a copper alloy, and a rectangular base material 14 surrounded by a separating through hole 13 partially joined by a plurality of connecting pieces 12 is pressed therein. It is formed by processing. A V notch 15 is also formed on the front surface and / or the back surface of the connecting piece 12 by a press process so that the base material 14 can be easily separated in a later step.

Next, as shown in FIGS. 1 (B) and 2 (B), an insulating adhesive is applied to the base material 14 leaving the edge portion thereof to form an adhesive layer 16. This process is performed by the screen printing method. Then, while the adhesive layer 16 does not dry, copper powder 17 which is an example of metal powder is applied slightly inside thereof as shown in FIGS. 1 (B) and 2 (C). The copper powder 17 may be applied by appropriately masking the base material 14 and spraying the copper powder 17, but usually, the copper powder 17 is put in a box having a screen at the bottom, This is placed on the adhesive layer 16 and copper powder 17 is sprinkled through the screen. As a result, the copper powder 17 bites into the adhesive layer 16, so that the copper powder 17 has sufficient strength and is fixed to the adhesive layer 16.

After the adhesive layer 16 has dried sufficiently, FIG.
As shown in (C) and FIG. 2 (D), other portions are masked with a resist film, and electroless copper plating is performed on the copper powder 17, whereby the copper powder 17 and the copper plating layer are separated. The conductor layer 1 that is difficult to peel off on the adhesive layer 16 as a unit
8 is formed.

Next, after covering the whole with a resist film, the lead pattern of the inner leads 19 is exposed / developed on the conductor layer 18, and is etched to form a pattern as shown in FIGS.
As shown in (E) and FIG. 3, inner leads 19 are formed on the adhesive layer 16. After that, a predetermined semiconductor element is fixed to the central element mounting portion 20 via an insulating tape, and predetermined wiring is performed with a conductive wire,
The base material 14 is separated from the portion of the V notch 15, and the inner lead 19 and the outer lead formed by pressing, for example, are fixed by soldering, pressure bonding, wiring, bonding using a conductive adhesive, or the like. After that, resin sealing is performed to complete the semiconductor device.

FIG. 4 shows a semiconductor element mounting substrate 21 manufactured according to another embodiment of the present invention. As shown in FIG.
3 is provided on the thin strip material 24 with an adhesive layer 25 interposed therebetween. This makes it possible to reduce the size of the semiconductor device and reduce the thickness thereof. The same components as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the above embodiment, the front end or the rear end of the inner lead may be plated with a noble metal in order to improve wiring or pressure bonding. Also in this case, since the positioning can be performed using the pilot hole, accurate plating can be performed. Further, the present invention can be applied to a semiconductor element mounting substrate used for a LOC or COL type semiconductor device having a bus lead for power supply and a grounding provided on the same plane as the inner lead.

[0013]

As is apparent from the above description, the method of manufacturing a semiconductor element mounting substrate according to the present invention forms an adhesive layer on a thin strip material, and coats metal powder on it. Since the conductor layer is formed by further plating, the adhesion between the lead pattern formed by the conductor layer and the thin strip material is very good. Since the adhesive layer and the conductor layer can be formed extremely thin, it is possible to form a thin semiconductor device. Further, since the thin strip material acts as a heat dissipation plate of the semiconductor element, there is an advantage that the semiconductor element is less likely to be thermally damaged.

[Brief description of drawings]

FIG. 1 is a plan view showing steps of a method of manufacturing a semiconductor element mounting substrate according to an embodiment of the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is an enlarged view of the same portion.

FIG. 4 is a plan view of a semiconductor element mounting substrate manufactured by a method according to another embodiment of the present invention.

[Explanation of symbols]

 10 Thin Strip Material 11 Pilot Hole 12 Connection Piece 13 Separation Through Hole 14 Base Material 15 V Notch 16 Adhesive Layer 17 Copper Powder 18 Conductor Layer 19 Inner Lead 20 Element Mounting Part 21 Semiconductor Element Mounting Board 22 Inner Lead 23 Inner Lead 24 Thin Strip Material 25 Adhesive Layer

Claims (1)

[Claims] 1. A pilot hole is formed on a side portion of a thin strip material, and a rectangular base material surrounded by a separating through hole whose inside and outside are partially connected by a plurality of connecting pieces is formed inside the pilot hole. , Applying an insulative adhesive to a specific area on the base material, further spraying and fixing metal powder in the uncured adhesive, and then plating on the scattered metal powder to form a conductor After forming a layer and covering the whole with a resist film,
A method of manufacturing a substrate for mounting a semiconductor element, comprising: exposing and developing a predetermined lead pattern on the conductor layer by a photographic method, and then forming the conductor layer into a lead pattern by etching.