JPS60253291A - Electronic part placing substrate and method of producing same - 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 elements or semiconductor elements, blocks moisture from entering the electronic components from the outside, The present invention also 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]

BACKGROUND ART Conventionally, electronic components such as semiconductor elements are directly mounted on printed wiring boards, and boards electrically connected by wire bonding are used as interior boards for watches, cameras, and the like. (a) of the drawing (Figure 5) shown later is an example of a board in which a semiconductor element is directly mounted on a printed wiring board, and a ceramic board or an organic resin board is used as the printed wiring board. There is. (bl
As shown in FIG. 1, there is a printed wiring board in which four parts are provided on the surface of the board where a semiconductor element is mounted by counterbore processing or laminated molding, and a semiconductor element is mounted in the recessed part.

[Problem that the invention seeks to solve]

However, these conventional printed wiring boards do not provide sufficient heat dissipation for the heat generated by the semiconductor elements mounted on them, and are only applied to semiconductor elements with relatively low output, that is, semiconductor elements that generate little heat, and high output When mounting a semiconductor device, it is necessary to take measures such as providing heat dissipation fins. In particular, organic resin substrates have lower thermal conductivity than metals and are inferior in heat dissipation from semiconductor elements. On the other hand, ceramic substrates such as alumina are also insufficient for mounting recently highly integrated high output semiconductor elements. In addition, the disadvantage of using organic resin substrates as semiconductor mounting substrates is that their moisture resistance is very low compared to ceramic substrates. Organic resin substrates can be used as semiconductor mounting substrates in fields where high reliability is required in terms of moisture resistance, as moisture can pass through the substrate and reach the semiconductor elements, corroding the semiconductor elements. Have difficulty.

[Problem that the invention seeks to solve]

In order to improve heat dissipation and moisture resistance, which are the drawbacks of the conventional printed wiring board, the present invention provides a metal plate on the back side of the printed wiring board and on the bottom of the recess through an adhesive layer. The present invention provides a board for mounting an electronic component, in which the electronic component is mounted, and a metal plating film is formed on the metal plate and both substrate surfaces.

Therefore, the heat generated from electronic components such as semiconductor elements can be efficiently dissipated through the metal plate, and by attaching the metal plate to the recess of the printed wiring board, the entire board can be made thinner. be.

Furthermore, the metal plating coating applied to the four parts where electronic components are to be mounted and the part where the metal plate on the back side of the recess comes into contact with the board prevents external moisture from penetrating through the adhesive layer and the board, allowing electronic parts to be mounted. This can prevent water from entering the area. An object of the present invention is to provide a substrate for mounting electronic components, which has extremely excellent heat dissipation properties and moisture resistance, and which can be made thinner as described above, and a method for manufacturing the same.

[Means and effects for solving the problems] The present invention will be specifically explained below based on the drawings.

First, for convenience, the steps shown in FIG. 2 of the method of manufacturing a substrate for mounting electronic components according to the present invention will be explained.

In Fig. 2, (al) is a vertical cross-sectional view of the back side of the printed wiring board (1) formed with four parts (9) by counterbore processing.A typical printed wiring board is made of glass fiber reinforced epoxy resin. substrates, paper phenol resin substrates, paper epoxy resin substrates, glass polyimide resin substrates, glass triazine resin substrates, etc.

Copper foil (2) is pre-coated on one or both sides of these boards.
Conductive films such as the above may be laminated and adhered. The size and depth of the four parts formed on the back side of the substrate are not particularly limited. Next, FIG. 2(b) shows the substrate (1
) is a vertical cross-sectional view in which a metal plating film is formed on the substrate surface including at least four parts (9) on the back side of the substrate. The recess (9)
The metal plating film (3) formed on the walls and bottom of the container is to prevent moisture from permeating. FIG. 2(C) is a longitudinal sectional view of a state in which a metal plate (6) is bonded to the inner bottom surface of the recess (&) on the back side of the printed wiring board (1) via an adhesive layer (ω). The adhesive layer is an uncured epoxy resin-impregnated glass cloth, a heat-resistant adhesive sheet, a liquid resin, etc., and an adhesive layer with high properties such as adhesiveness, heat resistance, and durability is preferable.On the other hand, a metal plate Copper, copper alloy, iron, iron alloy, aluminum, aluminum alloy,
Any material having relatively high thermal conductivity may be used.

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. As shown in FIGS. 3(a) and 3(b), the method for determining the mounting position of the metal plate is to adjust the planar shape of the recess (9) on the back side of the board so that at least two parts of the sides or corners Deformed board and CQ in Figure 3
It is advantageous to determine the mounting position of the metal plate by deforming at least two parts of the sides or corners of the planar shape of the metal plate (6) as shown in I and (d). (d) in FIG. 2 shows that the metal plate (6) is placed at the location where electronic components are to be mounted on the surface opposite to the back surface on which the four parts (9) are formed.
) by counterbore to expose a part of the four parts (8)
FIG. FIG. 2(e) shows a state in which the printed wiring board (1) and the metal plate (6) are integrated by forming a metal plating film (15) on both sides of the board including at least the four parts (8). FIG. The metal plating film (15) has the effect of blocking water from entering the adhesive layer between the printed wiring board (1) and the metal plate (6) and preventing water from entering the electronic component mounting area. By integrating (6) and copper foil (2) with a metal plating film, heat generated from electronic components is quickly conducted from the metal plate to the copper foil and radiated to the outside, which has the advantage of improving the heat dissipation effect. . FIG. 2(f) shows a semiconductor element (12) mounted on an electronic component mounting board according to the present invention, connected by wire bonding, and a resin (14) attached to the semiconductor element and its surrounding area.
FIG. In this drawing (14
) is a sealing resin, such as epoxy resin or silicone resin. Further, (7) is a weir frame for preventing the sealing resin from flowing out. The printed wiring board of the present invention manufactured in this manner has the characteristics shown in the longitudinal sectional view of FIG. The feature is that the front side of the organic resin substrate (1) has four parts (8) on which conductive circuits and electronic components are mounted, and the four parts (8) are in contact with the metal plate (6) on the back side. The substrate has at least a metal plating film (15) that is
There are four parts (9) on the back side of 1), a metal plating film (3) on the surface of the recess, and an adhesive layer (5) on the surface of the metal plating film.
A metal plate (6) is attached via a metal plate (6), and a metal plating film (15) is formed on the metal plate and both substrate surfaces. FIG. 4 is a perspective view of the plug-in package board of the present invention. This is a plug (9) in-package in which a large number of conductor pins (l) are arranged in the same row in a through hole (11) provided on the outer periphery of the electronic component mounting board.Shaded area (16) A thermosetting resin sheet (16) is attached to the outer periphery of the substrate and the surface of the through holes (11) as shown in 2. This is to completely cover the through holes.

〔Effect of the invention〕

As described above, 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, so that heat does not accumulate on the board, and external heat is not transmitted through the board to the mounted electronic components. Since there is almost no intrusion of moisture, the durability of electronic components is improved, and the printed wiring board after mounting can be made thinner.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of the printed wiring board of the present invention, FIG. 2 is a vertical cross-sectional view of the printed wiring board showing a flow sheet of the method for manufacturing the printed wiring board of the present invention, and FIG. 3 is a longitudinal cross-sectional view of the printed wiring board of the present invention. FIG. 4 is a plan view of a board of an alignment section on which a metal plate is mounted, FIG. 4 is a perspective view of a plug-in package board of the present invention, and FIG. 5 is a longitudinal cross-sectional view of a conventional electronic component mounting board. (lO) (1)・・・・・・・・・Printed wiring board (2)・
......Copper foil (3)...Metal plating layer (4)...
... Solder resist mask (5) ...
・・・Adhesive layer (6)・・・・・・Gold plate (7)・・・・・・Resin sealing frame (8)・・・・・・Concavity ( (4 parts for mounting the electronic part) (
9)...Four parts (four parts for attaching the metal plate) (10
)... Conductor bottle (11)... Through hole (12)... Semiconductor element (13)... Bonding wire (14)...
...Sealing resin (15) ...Metal plating layer (second plating layer) (16) ...Thermosetting resin sheet Patent applicant name IBIDEN Co., Ltd. Representative Jun Taga (11) Engraving of drawings (no change in content) Engraving of drawings (no change in content) (cl) (C) Coooooo (1') Procedural amendment (method) % formula %, of the case Indication: Patent Application No. 109910 filed in 1982, Title of invention: Substrate for mounting electronic components and its manufacturing method, Relationship with the person making the amendment. Applicant's residence: 2-1 Kanda-cho, Ogaki City, Gifu Prefecture, 503, Amendment. Date of order: August 8, 1982 (shipped on August 28, 1982);
Drawings to be amended, content of amendment as shown in the attached document Procedural amendment (method) September 20, 1980 Director General of the Patent Office Shiga Means 1989 Patent Application No. 109910 2 Title of invention Substrate for mounting electronic components and its Manufacturing method 3, relationship with the case of the person making the amendment Applicant's residence Address: 2-1-4 Kanda-cho, Ogaki-shi, Gifu 503;
Date of amendment order: August 8, 1980 (Shipped on August 28, 1980) Contents of amendment (1) “Brief explanation of drawings” column of specification No. 10
In line 15 of the page, the phrase “Figure 2 is...” has been replaced with “Figure 2 (a) to (0 are each...)
"..." I corrected myself.

Claims (1)

[Claims] 1. (a) forming a recess by counterboring on the back side of a printed wiring board made of an organic resin material; and (b) metal plating on the surface of the board including at least the recess on the back side. (03) a step of attaching a metal plate to the inner bottom surface of the recess via an adhesive layer; A method for manufacturing a board for mounting an electronic component, comprising the steps of: forming four parts by counterboring so that a part of the metal plate is exposed; and (el) plating both surfaces of the board including at least the recessed part. 3. The manufacturing method according to claim 1, wherein the steps (a) to (e) are performed with a large number of electronic component mounting substrates arranged in a grid. , a metal plating film is formed on the surface of the metal plate and the surface of the substrate at the same time.
The manufacturing method according to item 2. 4. The front side of the organic resin substrate has a recess on which a conductive circuit and electronic components are to be mounted, and the recess has at least a metal plating film in contact with the metal plate on the back side, and the organic resin A recess is provided on the back side of the substrate, a metal plated film is attached to the surface of the recess, and a metal plate is attached to the surface of the metal plated film via an adhesive layer, and a metal plated film is formed on the metal plate and both substrate surfaces. A board for mounting electronic components, characterized by: 5. The planar shape of the four parts on the back side is deformed in at least two parts of sides or corners to form alignment parts for attaching the metal plate. Board for mounting electronic components as described. 6. The metal plate according to claim 4, wherein the planar shape of the metal plate is deformed at at least two sides or corners to form alignment parts for mounting the metal plate. Board for mounting electronic components. 7. The electronic component mounting board according to claim 4, which is a plug-in package board in which a large number of conductor bins are strategically provided in holes provided on the outer periphery of the board. . 8. The substrate according to claim 4, wherein a thermosetting resin sheet is adhered to the outer peripheral portion and the hole surface.