JPH04245668A - Board for placing electronic component using heat sink slag - Google Patents

Abstract

PURPOSE:To provide a board for placing an electronic component, in which a heat sink slag can be effectively held therein when an electronic component package is employed to provide excellent durability as a whole. CONSTITUTION:A through hole 14 in which sealing resin 18 can be introduced through both part of a base material 11 for composing a board 10 for placing an electronic component and part of a heat sink slag 13, and the opening end of the hole 14 is disposed therein from the heat dissipating surface 13a of the slag 13.

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 electronic components, and more particularly to a substrate for mounting electronic components, which is equipped with a heat dissipation slug for active heat dissipation and is substantially entirely sealed with resin.

0002

[Prior Art] Electronic components such as chip components are used by being mounted on a board for that purpose, and after being mounted, the whole part, the connection part between it and the board side, bonding wires, etc. Sealing with resin is performed. In particular, in the case of a so-called electronic component package as shown in FIG. 3 or 4, it is common practice to seal the entire electronic component and electronic component mounting board with resin. On the other hand, electronic components generate heat during operation, and if the heat is not dissipated promptly, the functionality of the electronic component package as mentioned above may deteriorate, or in some cases, the electronic components may be protected. This may cause problems such as cracks occurring in the sealing resin that is supposed to be sealed.

[0003] Conventionally, therefore, heat dissipation slugs have been used to absorb heat from electronic components and dissipate it outward from a heat dissipation surface. As shown in FIG. 3 or 4, at least one surface of the heat dissipation slug must be exposed from the sealing resin, so it must be integrated with the electronic component mounting board. Otherwise, moisture, etc., which has an adverse effect on electronic components, etc., will enter the interior from between the heat dissipation slag and the sealing resin. Therefore, in the conventional heat dissipating slug, as shown in FIG. 3 or 4, measures such as forming a stepped part in the heat dissipating slug to be buried in the sealing resin are taken to prevent electronic components in the heat dissipating slug. This was done to ensure that it was integrated into the mounting board.

However, as mentioned above, electronic components such as chip components generate heat when they operate, and this heat causes damage between the electronic component mounting board and the heat dissipation slag, or between the heat dissipation slag and the sealing resin. However, peeling and cracking may occur even if the above-mentioned measures are taken, and the durability of the electronic component package may be impaired. There are various possible reasons for this, but typical examples include deterioration of the adhesive between the electronic component mounting board and the heat dissipation slug due to heat from the electronic components, and thermal expansion between the electronic component mounting board and the heat dissipation slug. Examples include differences in rates.

[0005] In view of the above-mentioned circumstances, the inventors of the present invention have conducted various studies on how to stabilize the heat dissipation slag within the sealing resin.
The present invention was completed.

[0006]

[Problems to be Solved by the Invention] The present invention has been made based on the above-mentioned circumstances, and the problem to be solved is to ensure that the heat dissipation slag is integrated with the sealing resin. .

[0007]An object of the present invention is to provide an electronic component package which, when used as an electronic component package, can reliably hold the heat dissipation slug inside and has excellent durability as a whole. To provide a component mounting board with a simple configuration.

[0008]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the means taken by the present invention are described with reference numerals used in the embodiments. It is equipped with a heat dissipation slug 13 for discharging the heat to the outside, and the heat dissipation slug 1 is centered on the mounted electronic component 17.
In the electronic component mounting board 10 which is sealed with the sealing resin 18 with the heat dissipation surface 13a of No. 3 exposed, a part of the base material 11 constituting the electronic component mounting board 10 and the heat dissipation A through hole 14 is formed in a part of the slug 13 so that the sealing resin 18 can enter therethrough, and the open end of the through hole 14 is connected to the heat radiation surface 13a of the heat radiation slug 13.
"Substrate 10 for mounting electronic components" characterized by being positioned further inside.

[0009]

In the electronic component mounting board 10 constructed as described above, a through hole 14 is formed in a portion of the base material 11 and a portion of the heat dissipation slug 13. Sealing resin 1 is applied to almost the entire electronic component mounting board 10.
8, a portion of the sealing resin 18 enters the through hole 14. That is, the electronic component 17 is mounted on this electronic component mounting board 10 and the sealing resin 18 is
When the electronic component package 20 is obtained by sealing the electronic component package 20, as shown in FIG. A connecting beam will be formed as a material, and both ends of this connecting beam will be connected to the sealing resin 18 located on both sides of the electronic component mounting board 10 in the drawing.

[0010] To explain this situation in more detail in accordance with each embodiment, in the embodiments shown in FIGS. There is. Therefore, the open end of each through hole 14 is completely located within the sealing resin 18 as shown in FIG.
8 is completely integrated with the sealing resin 18 located on both sides thereof, and the sealing resin 18 in the through hole 14 more reliably integrates the heat dissipating slug 13 with the base material 11.

Further, in the embodiment shown in FIGS. 4 and 5, each through hole 14 is formed in a portion of the heat radiation slug 13 that becomes the heat radiation surface 13a, and the outside of the opening end on the through hole 14 side A locking hole 16 formed in the heat dissipating slug 13 is located at the position. In other words, even in this case, the opening end of each through hole 14 is positioned within the sealing resin 18, and the sealing resin 18 when forming the electronic component package 20 is penetrated from the upper side as shown in FIG. The hole 14 is filled, and a portion thereof spreads inside each electronic component package 20. Therefore, the illustrated lower end of the sealing resin 18 filled in the through hole 14 is integrated with the sealing resin 18 filled in the electronic component package 20 and is locked in the locking hole 16. The upper end of the sealing resin 18 in the through hole 14 is integrated with the sealing resin 18 located above the electronic component mounting board 10, and as a result, the sealing in the through hole 14 is completed. The resin 18 ensures the integration of the electronic component mounting board 10 and the heat dissipation slug 13.

In any case, the sealing resin 18 filled in each through hole 14 is different from the sealing resin 18 located above and below it.
When solidified together, the base material 1 of the electronic component mounting board 10
This ensures that the heat dissipation slug 13 is integrated with the base material 11 and the heat dissipation slug 13, and even if there is a slight difference in thermal expansion coefficient between the base material 11 and the heat dissipation slug 13, the integration of the two is ensured. Therefore, if the electronic component package 20 is formed using this electronic component mounting substrate 10, in this electronic component package 20, the heat dissipation slug 13 is reliably integrated with the electronic component mounting substrate 10. As a result, the electronic component mounting board 10 and the heat dissipation slug 13 have a structure that is not affected by the heat generated by the electronic component 17 at all, and the durability when used as the electronic component package 20 is extremely high. be.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained in detail according to embodiments shown in the drawings.

Embodiment 1 FIGS. 1 to 3 show an electronic component mounting board 10 according to a first embodiment of the present invention.
The device mainly includes a base material 11 on which a large number of outer leads 12 and necessary conductor circuits are formed, and a heat dissipation slug 13 integrated in a housing formed on one surface of the base material 11.

Various types of electronic component mounting substrates 10 can be used, but in this embodiment, the base material 11 is integrated on both sides of a lead frame having a large number of outer leads 12. Along with this base material 1
1 with a predetermined conductor circuit (not shown) formed on the surface or the like. When the electronic component mounting board 10 is used to form an electronic component package 20 as shown in FIG. This is for making electrical connections to etc. In the embodiment shown in the figure, a heat dissipation slug 13 is positioned on one surface of the base material 11 constituting the electronic component mounting board 10, and a storage section for the electronic components to be mounted is provided. Although an example is shown in which this storage section is formed, this storage section is not necessarily required.

In this embodiment, the heat dissipation slug 13 is integrally formed of copper, and a stepped portion 15 is formed around it, which is completely embedded in the sealing resin 18. That is, this stepped portion 15 is located one step lower than the heat dissipating surface 13a that is completely exposed from the sealing resin 18 of the heat dissipating slug 13, and the outer surface of this stepped portion 15 is covered with the sealing resin 18. By this, when the electronic component mounting board 10 is used as the electronic component package 20, the heat dissipation slug 13 is more securely integrated with the electronic component package 20.

In this embodiment, even before the electronic component package 20 is formed, the heat dissipation slug 13 is integrated with the electronic component mounting substrate 10 using an adhesive. The adhesive for this integration is the heat dissipation slag 13 when the electronic component package 20 is completed.
It is not necessary to actively integrate the electronic component mounting board 10 into the electronic component mounting board 10, and to make it easier to perform various operations until the electronic component package 20 is completed, it is necessary to use a simple heat dissipation slug. 13 temporary fixings are sufficient.

The electronic component mounting board 10 constructed as described above has a part of its base material 11 and a heat dissipation slug 13.
A plurality of through holes 14 are formed to penetrate through a portion of the . The through holes 14 are formed in advance in both the base material 11 of the electronic component mounting board 10 and the heat dissipation slug 13 so that these through holes coincide with each other to form each through hole 14. Alternatively, the heat dissipation slug 13 may be integrated with the base material 11, but in this embodiment, each through hole 14 is formed by drilling a common hole in the heat dissipation slug 13 and the base material 11 that is integrated with the heat dissipation slug 13. was formed.

In this embodiment, each through hole 14 is formed at a position that does not interfere with each outer lead 12 or conductor circuit on the base material 11 side, and also at a position where the heat dissipation slug 13
This is the part corresponding to the stepped portion 15 of. As a result, the open end of each through hole 14 is completely located within the sealing resin 18 when the electronic component package 20 is formed, as shown in FIG.

As shown in FIG. 3, necessary electronic components 1 are mounted on the electronic component mounting board 10 configured as described above.
7 is mounted, the electronic component is sealed with the sealing resin 18 by means such as transfer molding, with the heat dissipating surface 13a of the heat dissipating slug 13 and each outer lead 12 exposed to the outside. package 2
It is set to 0. Since a predetermined pressure is normally applied to the sealing resin 18, a portion of the sealing resin 18 is completely filled into each through hole 14 by the pressure. As a result, the sealing resin 18 in each through hole 14 becomes completely connected to the sealing resin 18 in other parts,
This ensures that the heat dissipation slug 13 is integrated with the base material 11.

Embodiment 2 FIG. 4 shows an electronic component mounting board 1 according to Embodiment 2 of the present invention.
A cross-sectional view of an electronic component package 20 formed using 0 is shown, and the electronic component mounting board 10 adopted in this electronic component package 20 is as shown in FIGS. 4 and 5.
It has a heat dissipating slug 13 integrated with a base material 11. In this electronic component mounting board 10, the structure of the base material 11 having the outer lead 12 and the heat dissipation slug 13 are
Although the materials and the like are substantially the same as those of the electronic component mounting substrate 10 according to the first embodiment described above, there are differences in the formation position of each through hole 14 and the corresponding partial differences.

That is, in the electronic component mounting board 10 according to the second embodiment, each through hole 14 is formed on the heat dissipation surface 13a of the heat dissipation slug 13. and,
A locking hole 16 is formed outside the through hole 14 at the open end of each through hole 14 on the heat dissipation slug 13 side, and the diameter of each of these locking holes 16 is as shown in FIG. , it is larger than that of each through hole 14. As shown in FIG. 4, each of these locking holes 16 accommodates a portion of the sealing resin 18 that is filled through each through hole 14. is integrated with the sealing resin 18 in the through hole 14 and other parts,
This ensures more secure integration of the heat dissipation slug 13 with the electronic component mounting board 10. That is, each through hole 1
The sealing resin 18 in each through-hole 14 is solidified while being integrated with that in the locking hole 16, thereby ensuring the connecting beam effect of the sealing resin 18 in each through-hole 14.

[0023]

[Effects of the Invention] As detailed above, in the present invention,
As illustrated in each of the above embodiments, electronic component mounting board 1
The main feature is that through-holes 14 are formed in the base material 11 and the heat dissipation slug 13 of 0, and that the open end of each of the through-holes 14 is completely located within the sealing resin 18. As a result, when used as an electronic component package, it is possible to securely hold the heat dissipation slug inside, and the electronic component mounting board can be made to have excellent durability as a whole, with a simple configuration. It can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an electronic component mounting board according to a first embodiment of the present invention.

FIG. 2 is a plan view of the electronic component mounting board.

FIG. 3 is a cross-sectional view of an electronic component package constructed using the same electronic component mounting board.

FIG. 4 is a sectional view of an electronic component package constructed using an electronic component mounting board according to Example 2 of the present invention.

FIG. 5 is a bottom view of the electronic component mounting board.

[Explanation of symbols]

10　Substrate for mounting electronic components 11 Base material 13 Heat dissipation slag 13a Heat radiation surface 14 Through hole 15 Stepped section 16 Locking hole 17 Electronic parts 18 Sealing resin 20 Electronic component package

Claims (1)

[Claims] 1. A heat dissipation slug for dissipating heat from mounted electronic components to the outside, and sealed with the mounted electronic component in the center and the heat dissipation surface of the heat dissipation slug exposed. In an electronic component mounting board that is sealed with a resin, the sealing resin is applied to a part of the base material constituting the electronic component mounting board and a part of the heat dissipation slug by penetrating both. 1. A board for mounting an electronic component, characterized in that a through hole is formed into which the heat radiation slug can enter, and an open end of the through hole is located inside the heat radiation surface of the heat radiation slug.