JPH0758239A - Chip carrier - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a chip carrier having good heat dissipation and no warpage. A printed wiring board 1 including an insulating substrate 1a and a conductive circuit 10 formed on a mounting surface of an electronic component 7 mounted on the insulating substrate 1a, and a heat-radiating metal provided on the opposite side of the mounting surface. In the chip carrier including the layer 2, the pattern 9 in which the metal layer 2 generates stress that cancels thermal stress of the conductive circuit 10 due to heat from the electronic component 7
Are configured. Further, a thermal via that thermally connects the electronic component 7 and the metal layer 2 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip carrier used for mounting electronic parts such as semiconductor elements.

[0002]

2. Description of the Related Art As shown in FIG. 3, in a chip carrier provided with a metal layer (2) for heat dissipation attached to a printed wiring board (1), the metal layer (2) for heat dissipation is In order to prevent the heat of the electronic component (7) such as a semiconductor element wire-bonded to the conductive circuit (10) of 1) from being accumulated, it plays a role of radiating heat. Therefore, as a material for the metal layer (2) for heat dissipation, metals such as aluminum, copper and alloys thereof having good thermal conductivity are generally used.

This chip carrier is an insulating substrate (1a).
An electronic component (7) is mounted on the surface of the printed wiring board (1) formed with the conductive circuit (10) on which the conductive circuit (10) is formed, and the electronic component (7) and the printed wiring board (1). Bonding wire (6) for the conductive circuit (10)
And a metal layer (2) for heat dissipation is formed on the surface of the printed wiring board (1) opposite to the surface on which the conductive circuit (10) is formed. Since there is a difference in thickness or a material used between the conductive circuit (10) and the metal layer (2) for heat dissipation, thermal expansion causes a thick metal layer (2) for heat dissipation. However, there is a drawback in that a larger stress is generated than in the conductive circuit (10) having a small thickness, and the balance of forces is lost, so that bending stress is generated and the chip carrier is warped.

In particular, the thinner the insulating substrate (1a), the more remarkable the warpage.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a chip carrier which has good heat dissipation and does not warp.

[0006]

A chip carrier according to the present invention is a conductive material formed on a mounting surface of an insulating substrate (1a) and an electronic component (7) such as a semiconductor element mounted on the insulating substrate (1a). In a chip carrier provided with a printed wiring board (1) including a circuit (10) and a metal layer (2) for heat dissipation provided on the side opposite to the mounting surface, the metal layer (2) is an electronic component (2). It is characterized in that it is composed of a pattern (9) that generates a stress that cancels the thermal stress of the conductive circuit (10) by the heat from 7).

According to the present invention, the thermal via (5)
The electronic component (7) is thermally connected to the metal layer (2) via the.

[0008]

According to the present invention, the heat of the electronic component (7) such as a semiconductor element is transferred to the heat radiating metal layer (2) through the insulating substrate (1a) or the thermal via (5),
Heat is dissipated, but since the metal layer (2) for heat dissipation is formed in a slit-shaped or radial pattern (9),
Even if there is a difference in the thickness or the material used between the conductive circuit (10) and the metal layer (2) for heat dissipation, the stress of the conductive circuit (10) caused by heat and the heat dissipation And the stress of the metal layer (2) are canceled out.

[0009]

EXAMPLES The present invention will be described in detail below with reference to examples.

FIG. 1 is a sectional view illustrating a chip carrier according to an embodiment of the present invention. As shown in FIG. 1A, this chip carrier has a semiconductor element on a surface of a printed wiring board (1) having a conductive circuit (10) formed on the insulating substrate (1a). An electronic component (7) such as the like is mounted, and the electronic component (7) and the conductive circuit (10) of the printed wiring board (1) are bonded to each other by a bonding wire (6).
And a metal layer (2) for heat dissipation is formed on the surface of the printed wiring board (1) opposite to the surface on which the conductive circuit (10) is formed.

As the material of the metal layer (2), copper, aluminum and alloys thereof having good thermal conductivity may be used, and may be metal foil or plating. The forming method does not matter.

The thickness of the copper foil forming the conductive circuit (10) is preferably 9 μm to 18 μm, and the thickness of the metal layer (2) for heat dissipation is preferably 50 μm to 70 μm.

The metal layer (2) for heat dissipation is shown in FIG.
As shown in FIG. 7, the pattern is formed in a radial pattern (9) so that the stress between the heat-dissipating metal layer (2) and the conductive circuit (10) cancels each other out, so that the stresses cancel each other out and no warpage occurs. .

That is, in the pattern (9) for forming the metal layer (2) for heat dissipation, the exposed surface (3) where the insulating substrate (1a) is exposed and the insulating substrate (1a) are covered with the metal layer (2). Coating surface (4). This pattern (9)
Is not limited to a radial shape, and may be a lattice shape or a slit shape.

The heat generated from the electronic component (7) is transferred to the insulating substrate (1a), reaches the metal layer (2) for heat radiation, and is radiated.

Further, as shown in FIG. 2, this chip carrier has a through hole (1) penetrating the insulating substrate (1a).
When the electronic component (7) is mounted so as to close the through hole (11), it is provided with a thermal via (5) formed by covering 1) with copper or the like having good thermal conductivity that conducts heat. The heat generated from the electronic component (7) is conducted through the thermal via (5) having a higher thermal conductivity than that of the insulating substrate (1a) and is transmitted to the heat dissipation metal layer (2), so that the heat dissipation is increased. As a result, the effect of canceling the thermal stress between the conductive circuit (10) and the metal layer (2) is enhanced.

[0017]

According to the chip carrier of the present invention, the heat generated from the electronic component (7) such as a semiconductor element is transferred to the insulating substrate (1a), reaches the metal layer (2) for heat radiation and is radiated. . In this case, the pattern (9) formed on the heat-dissipating metal layer (2) generates a stress that cancels the stress of the conductive circuit (10) caused by heat, so that no warp occurs.

Further, the provision of the thermal vias (5) further improves the heat radiation performance of the heat generated from the electronic component (7), so that the effect of canceling the thermal stress is enhanced.

[Brief description of drawings]

FIG. 1 shows an embodiment of a chip carrier of the present invention,
(A) is sectional drawing, (b) is a top view.

FIG. 2 is a sectional view of a chip carrier according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a state where electronic components such as a semiconductor element are mounted on a chip carrier according to a conventional example.

[Explanation of symbols]

 1 Printed Wiring Board 1a Insulating Substrate 2 Metal Layer 5 Thermal Via 7 Electronic Component 9 Pattern 10 Conductive Circuit

Claims (2)

[Claims] 1. An insulating substrate (1a) and the insulating substrate (1)
A printed wiring board (1) comprising a conductive circuit (10) formed on a mounting surface of an electronic component (7) mounted on a) and a metal layer (2) for heat dissipation provided on the opposite side of the mounting surface. In the chip carrier provided with, the metal layer (2) is
A chip carrier comprising a pattern (9) for generating a stress that cancels a thermal stress of a conductive circuit (10) by heat from an electronic component (7). 2. Chip carrier according to claim 1, characterized in that the electronic component (7) and the metal layer (2) are thermally connected via a thermal via (5).