JP2632761B2 - Semiconductor element mounting substrate and method of manufacturing semiconductor element mounting substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A multi-layer semiconductor element mounting substrate used in a conventional semiconductor device is formed by laminating a plurality of thin metal plates formed in a predetermined shape to an intermediate portion thereof through an adhesive layer by press working. Alternatively, a metal foil is stuck on a resin plate having an insulating property, and a plurality of unit base materials that have been subjected to a predetermined etching process are bonded to each other with an adhesive. An inner lead is formed on the surface of the substrate for mounting a semiconductor element, and a semiconductor element is mounted at the center of the substrate for mounting a semiconductor element, and a pad portion of the semiconductor element and the inner lead are connected by a metal wire. The semiconductor device is manufactured by connecting the outer lead and the end of the inner lead, which are further prepared separately, and performing a well-known resin sealing.

[0003]

However, in the case of using a pressed metal plate in the semiconductor element mounting substrate according to the conventional example, each metal plate is bonded to an adhesive layer having a predetermined thickness (usually, Since the polymerization is carried out via a double-sided tape, the entire base material becomes thicker, and the semiconductor device using the same becomes thicker, which limits the application. Therefore, the conventional method has a problem that it is difficult to reduce the thickness of a high-density semiconductor device required in recent years. Further, by press working, shaping each metal sheet individually, when combining it heavy, prone to the metal plate Re not a position, Therefore, it is necessary to manufacture with great care, as a result There was also a problem that the cost was high. And when manufacturing the semiconductor element mounting substrate by polymerizing the unit base material,
In addition to the problem that the metal foil becomes thick, the metal foil on the surface may be peeled off during the assembling operation, which causes a problem in the subsequent assembling process. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a semiconductor element mounting substrate and a method for manufacturing a semiconductor element mounting substrate that can be reduced in thickness, are high-quality, and have low manufacturing costs.

[0004]

According to the present invention, there is provided a semiconductor device comprising:
In the substrate for mounting a semiconductor element described above, a semiconductor element is mounted in the center, and a number of inner leads, a power supply conductor layer, and a grounding conductor layer which are connected to a pad of the semiconductor element via a metal wire are formed in the periphery. In the substrate for mounting a semiconductor element provided in the above, a metal plate is used as a base material , an insulating adhesive layer to be joined to a lower layer on the base material, and a metal powder fixed to a surface of the adhesive layer. A lower insulating conductor layer composed of a layer and a plating layer formed on the surface of the metal powder layer, in the element mounting portion, a plurality of steps are formed so that each of the plating layers is sequentially exposed from a lower step; The upper plating layer is formed by forming the inner leads by photoetching. According to a second aspect of the present invention, there is provided a method of manufacturing a semiconductor device mounting substrate, wherein a pilot hole is formed in a side portion of a thin metal strip, and the inside and outside of the pilot hole are partially connected by a plurality of connecting pieces. Forming a rectangular substrate surrounded by the separation through-holes, first applying an insulating adhesive to a specific region of the substrate, spraying and fixing metal powder on the adhesive, A plurality of lower-layer insulated conductor layers are formed by performing a coating process of forming a conductive layer by plating on a metal powder sprayed a plurality of times, and in the coating process, a semiconductor element mounted at the center around, said by sequentially exposing the lower insulated conductor layer conductive layer from the lower, both <br/> a power conductor layer to form a conductor layer for grounding, the conductive layer of the outermost surface by photoetching Connected to the semiconductor element via a metal wire And it is configured so as to form inner leads to. In the above invention, it is preferable to use copper powder for the metal powder and copper plating for the plating.
Other metals or alloys can be used for the metal powder and the plating as long as they are nickel, a nickel alloy, or the like.

[0005]

According to the method of manufacturing a substrate for mounting a semiconductor element according to the first aspect and the method of manufacturing the substrate for mounting a semiconductor element according to the second aspect,
Since the metal plate is used as the base material , heat generated from the semiconductor element can be dissipated. Then, an adhesive layer is applied on the metal plate, a metal powder is formed thereon, and a lower insulated conductor layer plated on the metal powder is formed in a plurality of stages. The adhesion to the adhesive layer is good, and the plating is performed thereon, so that the conductive layer made of the metal powder and the plating can be prevented from peeling off. In the element mounting portion at the center of the lower insulated conductor layer, since the conductor layer is formed so as to be gradually exposed from the lower stage, these conductor layers can be used as ground (ground) and power supply. Accordingly, the wiring between the semiconductor element and the inner lead can be simplified, and a capacitor can be formed between the lower insulated conductor layers to avoid noise and the like, thereby having the effect of preventing malfunction of the semiconductor element. . Further, since the inner lead is formed in the uppermost plating layer by photoetching, a signal line from the element can be connected.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; Here, FIG. 1 is a process diagram showing a method for manufacturing a semiconductor element mounting substrate according to an embodiment of the present invention, FIG. 2 is a partially enlarged view of the semiconductor element mounting substrate, FIG. FIG. 4 is a plan view of a semiconductor element mounting substrate according to another embodiment. Although each manufacturing process is schematically shown in FIG. 1 by using a substrate of an adjacent lead frame, FIGS.
(I) shows a group of each processing step individually.

As shown in FIG. 1 (A), a predetermined pilot hole 10a is formed in a thin strip member 10 made of copper or a copper alloy, and a plurality of connecting pieces 11 are used to partially separate the pilot hole 10a therein. A rectangular base material 13 surrounded by the through holes 12 is formed by press working. The connection piece 11
A V-notch 14 is also formed on the front and / or back surface by press working in a later step so that the substrate 13 can be easily separated.

Next, as shown in FIG.
Is applied with an insulating adhesive while leaving its edge. This process is performed by a screen printing method. Then, while the first adhesive layer 15 does not dry, a copper powder 16 which is an example of a metal powder is applied as shown in FIG. The copper powder 16 may be applied by performing appropriate masking on the substrate 13 and spraying the copper powder 16, but usually, the copper powder 16 is put in a box having a screen at the bottom, This is put on the first adhesive layer 15, and the copper powder 16 is dropped through the screen to be bonded to a predetermined area of the first adhesive layer 15. As a result, the copper powder 16 bites into the first adhesive layer 15, so that the copper powder 16 has a sufficient strength and is fixed to the first adhesive layer 15. After the first adhesive layer 15 is sufficiently dried, other portions are masked with a resist film, and electroless copper plating is performed on the copper powder 16 as shown in FIG. As a result, the copper powder 16 and the copper plating layer are united to form the first conductive layer 17 that is difficult to peel off on the first adhesive layer 15, and the first lower insulated conductive layer is formed by the above processing. To form

Then, as shown in FIG. 1E, an insulating adhesive is applied on the first conductor layer 17 by a screen printing method, leaving an area 18 slightly larger than the central element mounting portion. Then, a second adhesive layer 19 is formed. The outside of the second adhesive layer 19 may completely cover the first conductor layer 17 or may be slightly left as in this embodiment. While the second adhesive layer 19 is uncured, a copper powder 16 is applied by the same processing as described above, and electroless plating is performed thereon. Is formed, thereby forming a second lower insulated conductor layer.

Thereafter, an insulating adhesive is further applied on the second conductor layer 20 by a screen method, and FIG.
As shown in (3), the third adhesive layer 21 is formed in such a manner that the second conductor layer 20 is exposed to a small width in the peripheral region of the inner element mounting portion. Then, a copper powder 16 is applied on the third adhesive layer 21 by the same method as described above, and after sufficiently dried, copper plating is performed thereon.
And the uppermost lower insulated conductor layer is formed. Next, after the whole is covered with a resist film, the inner leads 23 are photo-etched on the third conductor layer 22.

Thereafter, as shown in FIG. 3, a predetermined semiconductor element 24 is fixed at the center via an insulating tape, and the semiconductor element 2 is connected to a metal wire made of copper, aluminum, gold wire or the like.
4 and the inner lead 23 are connected. In this case, a large number of grounds provided on the semiconductor element 24 are provided.
And the connection of the power supply is connected to the first and second conductor layers 17 and 20 exposed inside. And the V notch 1
After separating the base material 13 in four parts, the base lead 13 is connected to an outer lead formed by press working. The connection between the inner lead and the outer lead is performed by soldering, direct pressure bonding,
The bonding may be performed using a metal wire, or the bonding may be performed using a conductive adhesive. Also, the connection between the first and second conductor layers 17 and 20 and the outer leads is connected to a specific inner lead on the surface by using a well-known inner barrier hole, and the inner lead and the outer lead are connected. Alternatively, a portion of the first and second conductor layers 17 and 20 may be exposed to the outside, and bonding may be performed using a metal wire. Through the above steps, the base material 13 on which the semiconductor element 24 is mounted and the predetermined connection is made, and a part of the outer leads are resin-sealed, and a thin semiconductor device is completed.

In the above-described embodiment, the case where one semiconductor element is mounted on one base material has been described, but a plurality of inner lead groups 26 and 27 are formed on one base material 25 as shown in FIG. The present invention can also be applied to a semiconductor device in which a plurality of semiconductor elements are mounted. In this case, a ground (earth), power supply, and the like common to these semiconductor elements can be used as a common conductor layer. In the above embodiment, the thin strip material at the bottom only functions as a heat sink, but the formation of the third plating layer is omitted, and the inner lead is photo-etched on the second plating layer. The present invention is also applicable to the case where the first plating layer and the strip material are used as a power supply or ground line.

[0013]

According to the method for manufacturing a substrate for mounting a semiconductor element according to the first aspect and the method for manufacturing a substrate for mounting a semiconductor element according to the second aspect, an insulating adhesive layer is provided on a base made of a thin strip.
Since the lower insulated conductor layer composed of the metal powder layer fixed to the surface of the adhesive layer and the plating layer formed on the surface of the metal powder layer is formed in a plurality of stages, the multi-layer structure by the conventional manufacturing method is used. It can be made thinner than a semiconductor element mounting substrate. As a result, a thin semiconductor device can be provided. In addition, the upper and lower conductor layers do not displace, thereby making it easier to form inner barrier holes for connecting the upper and lower conductor layers or the inner leads, and to manufacture a semiconductor device at low cost. Furthermore, the uppermost inner lead and the lower plating layer did not peel off during assembly, and the yield was improved, and the reliability of the semiconductor device was also improved.

[Brief description of the drawings]

FIG. 1 is a process chart showing a method for manufacturing a semiconductor element mounting substrate according to one embodiment of the present invention.

FIG. 2 is a partially enlarged view of the semiconductor element mounting substrate.

FIG. 3 is a partially enlarged sectional view of the same.

FIG. 4 is a plan view of a semiconductor element mounting substrate according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Thin strip material 10a Pilot hole 11 Connecting piece 12 Separation through hole 13 Base material 14 V notch 15 First adhesive layer 16 Copper powder 17 First conductor layer 18 Area 19 Second adhesive layer 20 Second Conductor layer 21 Third adhesive layer 22 Third conductor layer 23 Inner lead 24 Semiconductor element 25 Base 26 Inner lead group 27 Inner lead group

Claims (2)

(57) [Claims] 1. A semiconductor element is mounted in the center, and a number of inner leads, a power supply conductor layer, and a grounding conductor layer are provided in layers around the periphery of the semiconductor element and connected to a pad of the semiconductor element via a metal wire. in the substrate for mounting a semiconductor element, with the use of metal plates to the substrate, on to the substrate, insulating adhesive layer, the metal powder layer is adhered to the surface of the adhesive layer and the metal to be bonded to the lower layer A lower insulated conductor layer made of a plating layer formed on the surface of the powder layer is formed in a plurality of stages in the element mounting portion such that the plating layers are sequentially exposed from a lower stage, and furthermore, an uppermost plating layer A substrate for mounting a semiconductor element, wherein the inner leads are formed by photoetching. 2. A square base material in which a pilot hole is formed in a side portion of a thin metal strip, and a pilot hole is formed inside the pilot hole and is surrounded by a separation through hole whose inside and outside are partially connected by a plurality of connecting pieces. Is formed, first, an insulating adhesive is applied to a specific area of the base material, and a metal powder is sprinkled and fixed on the adhesive, and then plating is performed on the sprinkled metal powder. A film forming process for forming a layer is performed a plurality of times to form a plurality of lower insulated conductor layers, and in the film forming process, a conductive layer of the lower insulated conductor layer is formed around a semiconductor element mounted at the center. the by sequentially exposed from the lower, together to form the power supply conductor layer for grounding conductor layer, the conductive layer of the outermost surface to form a inner leads connecting through the metal wire to the semiconductor device by a photo-etching process Characterized by the half A method for manufacturing a substrate for mounting a conductive element.