JPS61189697A - Substrate for carrying electronic component and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention improves heat dissipation from electronic components such as chip devices or semiconductor devices, and blocks moisture from entering the electronic components from the outside. The present invention relates to a highly reliable electronic component mounting board that can be made thin and compact, and a method for manufacturing the same.

[Conventional technology]

Conventionally, electronic components such as semiconductor elements are mounted directly on printed wiring boards, and the boards are electrically connected using wire bonding and are used as interior boards for watches, cameras, etc. (a) of the condensing drawing (Fig. 5) is an example of a board in which a semiconductor element is directly mounted on a printed wiring board, and the printed wiring board may be a ceramic board or
An organic resin substrate is used. As shown in FIG. 5(b), there is a printed wiring board in which a recess is formed on the surface of the substrate in a semiconductor element mounting portion by counterbore processing or laminated molding, and a semiconductor element is mounted within the recess.

[Problem that the invention seeks to solve]

However, in these conventional printed wiring boards,
Sufficient heat dissipation cannot be obtained for the heat generated by the mounted semiconductor elements, so it is applied to semiconductor elements with relatively low output, that is, semiconductor elements that generate little heat, and when mounting high output semiconductor elements, Measures such as installing fins for heat radiation are required. In particular, organic resin substrates have low thermal conductivity and extremely poor heat dissipation from semiconductor elements. On the other hand, even ceramic substrates made of alumina or the like have insufficient heat dissipation when recent highly integrated high output semiconductor elements are mounted thereon. Another problem with organic resin substrates as semiconductor mounting substrates is that their moisture resistance is very low compared to ceramic substrates, so organic resin printed wiring boards with the structure shown in Figure 5(b) are susceptible to moisture from outside. It is difficult to use organic resin substrates as semiconductor mounting substrates in fields where high reliability with respect to moisture resistance is required because they corrode semiconductor elements by penetrating the substrate and reaching the semiconductor elements. be.

[Means to be Solved by the Invention and Their Effects] The present invention provides a method for simultaneously improving heat dissipation and moisture resistance, which are the drawbacks of the conventional printed wiring boards, by having a metal coating inside the printed wiring board. A recess on which electronic components are to be mounted is formed on the front side of the board, a metal plate attached to the back side of the board is exposed on the bottom of the recess, and a metal coating inside the board is exposed on the side wall of the recess, Thereafter, the present invention provides a board for mounting electronic components in which the metal plate and the metal coating are integrated by a metal plating coating inside the recess.

When an electronic component such as a semiconductor element is mounted in the recess of the substrate, heat generated from the electronic component is efficiently and reliably diffused to the outside of the substrate via the metal plate and the inner metal coating.

Furthermore, the metal coating inside the board and the metal plate are integrated by the metal plating coating inside the recess, making it possible to completely prevent moisture from entering from outside through the printed wiring board.

Further, since the metal plate is attached to the recess on the back surface of the substrate, there is almost no increase in the overall thickness of the substrate, so it is possible to make the substrate thinner.

As mentioned above, the present invention has extremely excellent heat dissipation properties and moisture resistance,
The object of the present invention is to provide a substrate for mounting electronic components that can be made thin and a method for manufacturing the same.

The present invention will be specifically explained below based on the drawings.

First, for convenience, the method of manufacturing a substrate for mounting electronic components according to the present invention will be explained with reference to the steps shown in FIG.

Figure 2 (a) shows a printed wiring board (2) made of another organic resin material on at least the metal coated surface (a) of a printed wiring board (1) made of an organic resin material with an adhesive layer. ) is a vertical cross-sectional view of a substrate (5) laminated via a substrate (5).

Typical printed wiring boards include glass fiber-reinforced epoxy resin boards, paper phenol resin boards, paper epoxy resin boards, glass polyimide resin boards, and glass triazine resin boards. A metal coating such as copper foil is previously formed on one or both sides of these substrates. The adhesive layer may be an uncured epoxy resin-impregnated glass cloth, a heat-resistant adhesive sheet, a liquid resin, etc.
Adhesive layers with high properties such as adhesiveness, heat resistance, and durability are preferred.

Next, in (b) of FIG. 2, counterboring is performed from the surface of the multilayer board (5) opposite to the part where the electronic components are to be mounted.
FIG. 3 is a longitudinal cross-sectional view of a laminated substrate (5) in which a recess (6) is formed so that the inner metal coating layer is not exposed. Alternatively, after forming the recess (6) in the printed wiring board (1), the printed wiring board (2) may be laminated.

FIG. 2(c) shows an adhesive layer (4) on the inner bottom surface of the recess (6).
) is a vertical cross-sectional view of a state in which metal plates (7) are joined via a metal plate (7). The metal plate preferably has a relatively high thermal conductivity, such as copper, copper alloy, iron, iron alloy, aluminum, aluminum alloy, or the like. Although the size and thickness of the metal plate are not particularly limited, a thicker plate and a larger surface area are advantageous in improving heat dissipation. The method of determining the position to attach the metal plate is as shown in FIG. 3(a).
As shown in (b), the planar shape of the recess (6) on the back side of the substrate is deformed in at least two places, the sides or the corners, and in (c) and (d) of FIG. (
It is advantageous that at least two sides or corners of the planar shape of 7) are deformed, and the position at which the metal plate is attached is determined by these deformed parts. (d) in FIG. 2 shows that the metal plate (7) is exposed on the bottom surface at the location where the shim component is to be mounted on the opposite side of the back surface of the board where the recess (6) is formed, and the side wall surface is covered with metal. Place the laminated substrate (
5) is a vertical cross-sectional view of a state in which a recessed portion (8) is formed by counterboring. FIG. 2(e) shows the recess (8).
) is a cross-sectional view of a state in which a metal plating film (9) is formed on both surfaces of the laminated substrate including at least the inside. Examples of metal plating films include steel, nickel, gold, and tin. Due to the metal plating, the metal plate (7) and the metal coating (a) on the bottom of the recess are completely integrated.

FIG. 1 is a cross-sectional view of the electronic component mounting board of the present invention, in which a circuit is formed on the surface of the board by a conventional method.

FIG. 2(f) shows the semiconductor element (12) being die-bonded into the recess of the electronic component mounting board of the present invention, and the circuit of the semiconductor element and the board being connected with a gold wire (I3).
FIG. 2 is a cross-sectional view of a state in which the periphery of a semiconductor element is sealed with an epoxy resin (14). In this figure, (11) is a frame for preventing epoxy resin from flowing out, and is a laminate made of organic resin. Since the heat generated from semiconductor elements is dissipated in large quantities and reliably into the atmosphere through the metal plate (7) and metal plating film (a), it is easier to mount high-output semiconductor elements than on conventional printed wiring boards. In addition, in the recess for mounting electronic components, the metal plating film (9), the metal film (a), and the copper plate (7) are completely integrated, so that external moisture does not pass through the board. Since it is extremely rare for the particles to reach the semiconductor device, the life of the semiconductor device is significantly improved.

FIG. 4 is a perspective view of a pin grid array substrate according to one aspect of the present invention. This is a bin grid array in which a large number of conductor pins (16) are arranged in a circumferential row on a through-hole A/ (15) provided on the outer periphery of the electronic component mounting board. A thermosetting resin sheet (17) is attached to the shaded area (the outer circumference of the substrate and the surface of Sulfo-A/(15) shown in one). This is to completely cover the through holes.

〔Effect of the invention〕

As described above, since the electronic component mounting board of the present invention has high heat dissipation properties even when electronic components that generate a large amount of heat are mounted, heat does not accumulate on the board, and heat does not pass through the board to the mounted electronic components. The circuit board has the characteristic that there is very little intrusion of external moisture, and the life of electronic components mounted on the circuit board is significantly extended.

[Brief explanation of drawings]

FIG. 1 is a vertical i-plane view of the printed wiring board of the present invention, FIG. 2 is a longitudinal cross-sectional view of the board showing a flow sheet of a method for manufacturing the printed wiring board of the present invention, and FIG. 3 is a vertical cross-sectional view of the printed wiring board of the present invention. FIG. 4 is a perspective view of a plug-in package board of the present invention, and FIG. 5 is a vertical cross-sectional view of a conventional electronic component mounting board. (B)...Metal coating (B)...Adhesive layer (C)......On the surface of the board on which electronic components are mounted) ......The bottom outer surface of the recess for attaching the metal plate (
1), (2)... Printed wiring board (4) -...
...Adhesive layer (5)...! ... Laminated board (6) ... Recess (recess for mounting metal plate) (7)
・・・・・・Metal plate (8)・・・・・・Recess (recess for mounting electronic components) (
9)・・・・・・Metal plating film (10)・・・
...Solder resist mask (11)...
... Resin sealing frame (12) ... Semiconductor element (13) ... Bonding wire (14) ... Sealing Stopper resin (15)... Sulfo-μ (16)...
......Conductor pin (17)...Thermosetting resin sheet (b) (c)

Claims (1)

[Claims] 1. (a) A printed wiring board (1) made of an organic resin material having a metal coating (A) on at least one side, with an adhesive layer (B) on the metal coating (A). (b) manufacturing a laminate (5) by laminating and integrating a printed wiring board (2) made of another organic resin material; The side surface is counterbored, and the inner layer metal coating (
(b) forming a recess (6) so that the recess (6) is not exposed; (c) attaching a metal plate (7) to the bottom surface of the substrate within the recess (6) via an adhesive layer (4); d) In the substrate, the base material on the opposite side to the surface on which the metal plate is attached is cut by counterboring, exposing a part of the metal coating (a) on the cut side wall surface, and exposing the metal plate on the bottom surface. (e) forming a metal plating film (9) on the surface of the substrate including at least the inside of the recess (8);
(a) for integrating electronic components with the metal plate (7) using a metal plating film (9); and (f) for forming a circuit on the board manufactured through the above steps using a conventional method. Substrate manufacturing method. 2. A metal plate (7) is attached via an adhesive layer (4) in a recess (6) on the back side of a printed wiring board made of an organic resin material having a metal coating (a) on the inner layer, and A recess (8) for mounting electronic components is formed on the upper surface of the substrate, the metal plate (7) is exposed at the bottom of the recess, and the inner metal coating (A) is exposed at the side wall of the recess. In a substrate for mounting electronic components: The inner layer of the substrate for mounting electronic components has a metal coating (a) which is a smooth surface substantially parallel to the surface of the substrate via an adhesive layer (b), and the metal coating (i) ) are the recesses (6) formed on both sides of the board surface (c) and metal plate (7) on the electronic component mounting side.
The metal plate (7) and the metal plating film (9) are bonded to form the bottom surface of the electronic component mounting recess (8), and the metal plate (7) and the metal plating film (9) are bonded to Film (9
) and one end surface of the metal coating (a) on the inner layer of the board are joined in a perpendicular state to form a side wall surface of the electronic component mounting recess (8). . 3. The planar shape of the recess (6) on the back side of the laminated board (5) is deformed in at least two places, either sides or corners, to form alignment parts for mounting the metal plate. A substrate for mounting electronic components according to claim 2. 4. The planar shape of the metal plate (7) is deformed at at least two sides or corners to form alignment parts for mounting the metal plate. Substrate for mounting electronic components as described in section. 5. A hole (15) provided on the outer periphery of the laminated substrate (5)
3. The electronic component mounting board according to claim 2, wherein the electronic component mounting board is a pin grid array board in which a large number of conductor pins (16) are provided in circumferential rows on the board. 6. The electronic component mounting board according to claim 2, wherein a thermosetting resin sheet (17) is adhered to the outer peripheral portion of the board and the surface of the hole (15).