JP2583507B2 - Semiconductor mounting circuit device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a circuit device in which a semiconductor element is mounted and arranged on a wiring board. The present invention relates to improvement of a semiconductor mounting circuit device in consideration of performance.

(Prior art) A mounting circuit in which semiconductor elements such as integrated circuit elements (ICs), transistor elements, field effect transistors (FETs), and diode elements are mounted on a wiring board (printed wiring board, ceramic wiring board). The equipment (electronic parts)
It is widely used in the fields of industrial electronic equipment and consumer electronic equipment. The mounting and disposition of a semiconductor element on a wiring board of this type has attracted attention as a so-called high-density mounting technique. Here, for example, in the case of a multi-chip module, 30% to 70% is required for the mounting efficiency indicated by “total of chip areas to be mounted / mounted / area of wiring board × 100%”. By the way, in a mounted circuit device (or integrated circuit component) formed by mounting the above semiconductor elements, as the number of mounted semiconductor elements increases and the chip size increases (high integration), heat generated by the semiconductor elements and the like is reduced. The problem is how to effectively dissipate. That is, heat generated by the operation of the semiconductor elements to be mounted has a bad influence on the performance of the semiconductor elements. Under these circumstances, a high-density mounting technology that employs a configuration as shown in FIG. 2 is conventionally known. That is, according to the size of the semiconductor element (semiconductor chip) to be mounted / disposed (mounted),
A so-called heat sink 3 in which a through hole is selectively formed in the wiring board 1 and a projection 2 is provided so as to engage with the through hole.
Are combined. In this case, the upper end surface of the projecting portion 2 of the heat sink 3 is substantially flat with the surface of the wiring board 1, and is integrated with the wiring board 1 by an adhesive layer 4. Thus, the semiconductor element 5 is insulated and mounted on the surface of the protrusion 2 of the heat sink 3 integrated with the wiring board 1 and the input / output terminals are connected to the circuit pattern terminals 6 on the wiring board 1. They are electrically connected by wires 7.

However, in the above configuration, the degree of insulation is adjusted depending on the electrical insulation between the mounted / mounted semiconductor element 5 and the heat sink 3 or the type and capacity of the mounted / mounted semiconductor element. Inevitably, the complexity of processes and the like cannot be avoided. In addition, in the case of this configuration, the semiconductor element 5 cannot be mounted and mounted only after the heat sink 3 is combined with the wiring board 1, and the wiring area of the mounting board 1 is reduced by drilling. Therefore, there is a limit to high-density mounting. Here, a reduction in the area where wiring is possible leads to a reduction in wiring density, which impairs the enhancement of circuit functions.

Further, the wiring board 1 and the heat sink 3 are bonded to the adhesive layer 4.
However, due to the effects of the wettability and voids of the adhesive layer 4 and the difference in the coefficient of thermal expansion between the wiring board 1 and the heat sink 3, cracks occur in the adhesive layer 4 and poor airtightness ( (Leakage defect), and there was also a problem in reliability. In addition, it is necessary to secure an extra necessary installation area, which leads to a decrease in the mounting efficiency.

(Problems to be Solved by the Invention) Therefore, the present invention achieves sufficient heat radiation without any complicated steps, and achieves high-density wiring, and thus, improvement in mounting efficiency, high functionality and high reliability. It is an object of the present invention to provide a possible semiconductor mounting circuit device.

[Structure of the Invention] (Means for Solving the Problem) In a semiconductor mounting circuit device according to the present invention, a concave portion is selectively formed in a thickness direction, and a predetermined inner layer circuit pattern including a lower region of the concave portion is formed. Having a wiring board, a Cu-W-based metal piece mounted in a recess of the wiring board,
A semiconductor element mounted and disposed on the exposed surface of the Cu-W-based metal piece, and connection means for electrically connecting input / output terminals of the mounted semiconductor element to predetermined circuit pattern terminals. At least a power supply layer and a ground layer are arranged and built in (inner layer) in a lower region of the concave portion.

(Operation) According to the present invention, a Cu-W-based metal piece is mounted so as to be immersed in a region of a wiring board surface where a semiconductor element is mounted, and the upper surface (exposed surface) of this Cu-W-based metal piece is mounted. The semiconductor element is mounted on (). In other words, a metal layer region is selectively formed on the other surface (front surface) side while a continuous wiring board surface is formed on one surface (back surface) side, and required elements are formed on the metal layer region surface. It is mounted and electrically insulated from the heat sink. For this reason, it is not necessary to particularly adjust the treatment for the electrical insulation of each semiconductor element to be mounted, and furthermore, since the Cu-W-based metal piece has a thermal expansion coefficient substantially equal to that of the mounted element or the wiring board, in the operation process, Cu of mounted element
There is no danger of peeling or detachment from the -W based metal piece and peeling or detaching of the Cu-W based metal piece from the wiring board.

In particular, in the wiring board, the fact that the lower side of the concave portion can be secured as a wiring area not only can improve the function and the density by wiring, but also at least the power supply layer and the grounding layer can be arranged in the inner layer. Therefore, when the semiconductor element mounted and mounted is a power element,
It can respond to the demand for high functionality. in addition,
It is also possible to eliminate the possibility that the wiring board (package) leaks due to the mounting of the Cu-W based metal piece.

(Example) Hereinafter, an example in which a power transistor chip is mounted (mounted) using a substrate made of alumina ceramic will be described.

FIG. 1 is a sectional view showing a semiconductor mounted circuit device (integrated circuit component) in which a heat sink is attached to an integrated circuit component on which a power transistor element is mounted. In FIG. 1, reference numeral 1 denotes a wiring board, which includes a first circuit board layer 1b having an inner wiring 1a including a signal wiring layer, a power supply layer, and a ground layer, and a second circuit board layer 1d having a concave portion 1c. I have. Reference numeral 3 denotes a heat sink bonded and integrated to the back side of the wiring board 1, reference numerals 5 and 5 'denote power transistor elements,
6 is a circuit pattern terminal on the surface, 7 is an Au or Al thin wire, 8 is a metallized layer provided on the first circuit board layer 1b, and 9 is mounted and arranged in the recess 1c of the wiring board 1. Cu
Reference numeral 10 denotes a conductor for electrically connecting between the signal wiring layer and the inner layer pattern 1a including the power supply layer and the ground layer.

Next, an example of manufacturing the semiconductor mounted circuit device having the above configuration will be described. First, a first circuit board layer 1b having an inner layer wiring is formed using a so-called green sheet, and furthermore, a position for mounting a semiconductor element, a region and a hole for conduction are cut out, and a required circuit pattern is formed on the surface. The formed green sheets (indicating the second circuit board layer) were laminated and integrally pressed and fired. In this case, a metallized layer is previously formed on the exposed surface of the first circuit board layer 1b, that is, on the portion corresponding to the hollow portion of the green sheet laminated thereon. Cu-W having substantially the same coefficient of thermal expansion as the transistor element and the wiring substrate on the metallized layer in the concave portion of the wiring substrate having the concave portion formed in the predetermined region thus obtained.
Attach and arrange the system metal pieces. In the case of a ceramic wiring board, the mounting and disposing of the Cu-W-based metal piece may be performed by sintering the green sheet and brazing the Cu-W-based metal piece Ag.

Thereafter, the transistor elements are mounted and mounted on the exposed surfaces of the arranged Cu-W-based metal pieces, that is, the surfaces of the Cu-W-based pieces that are substantially the same as the wiring board surface. Next, the input / output terminals of the mounted transistor element are connected to a circuit pattern terminal formed in advance on the wiring board surface, for example, Au.
By wire bonding a thin wire such as a wire or an Al wire, the wires are electrically connected and required mounting is performed.

In the above description, since the example in which the power transistor element is mounted is described, the Cu-W-based metal piece 9 mounted in the concave portion 1c of the wiring board 1 is used as a connection conductor with the collector. Depending on the type, an insulating layer may be appropriately formed on the mounting surface. Further, the semiconductor element to be mounted is not limited to the power transistor, but may be an integrated circuit element, an FET element, a diode element, a combination thereof, or a combination with another electronic component such as a capacitor or a resistor.

[Effects of the Invention] As described above, according to the present invention, a region for mounting a semiconductor element on a wiring board is formed in a concave portion, and a Cu-W-based metal piece is mounted in the concave portion. In which the device is mounted. Since the Cu-W-based metal pieces are electrically insulated by the insulator constituting the main component of the wiring board, the Cu-W-based metal pieces have an adverse electrical effect through other semiconductor elements to be mounted or a heat sink to be mounted. There is no fear of inviting. That is, even when a heat sink is attached between the semiconductor elements to be mounted in the mounting of the semiconductor element or when a separate heat sink is attached, required mounting can be performed without considering electrical insulation between the heat sink and the semiconductor element. In particular, even in the case where a heat sink is attached in consideration of improvement in heat dissipation, the ability to attach the heat sink after mounting the semiconductor element is effective as mass-production mounting means. In addition, at least a power supply layer and a ground layer are arranged and arranged below the mounting area of the Cu-W-based metal piece, thereby maintaining a high wiring density and not only lowering the mounting efficiency, The so-called noise characteristic is greatly improved in circuit, and the reliability is improved. In addition, since the occurrence of a package leak defect is avoided in the wiring board due to the mounting of the Cu-W-based metal piece, high reliability can be maintained.

Thus, since the area where the semiconductor element is mounted is a metal piece, the thermal conductivity is good, the heat generated from the mounted element is easily radiated, and more circuit wiring areas can be secured in the wiring board, It can be said that the present invention brings many practical advantages in combination with the fact that high-density mounting is easy to achieve.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an integrated circuit component formed by mounting a semiconductor element by the method of the present invention, and FIG. 2 is a sectional view showing an example of an integrated circuit component formed by a conventional mounting means. DESCRIPTION OF SYMBOLS 1 ... Wiring board 1d ... Depression 5 '... Transistor element (semiconductor element) 6 ... Circuit pattern terminal 9 ... Cu-W type piece (metal piece)

Continuation of the front page (56) References JP-A-58-56443 (JP, A) JP-A-53-81957 (JP, A) JP-A-53-84164 (JP, A)

Claims (1)

(57) [Claims] 1. A wiring board in which a concave portion is selectively formed in a thickness direction and has a predetermined inner layer circuit pattern including a lower region of the concave portion, and a Cu-W mounted in the concave portion of the wiring substrate. And a semiconductor element mounted on the exposed surface of the mounted Cu-W-based metal piece, and electrically connecting input / output terminals of the mounted semiconductor element to a predetermined circuit pattern terminal. And a connecting means for connecting the power supply layer and the grounding layer at least in a region below the concave portion.