JPS5850027B2 - semiconductor equipment - Google Patents

Abstract

PURPOSE:To contrive to prevent flowing out of solder material, and to enhance the visual contrast of a semiconductor device by a method wherein semiconductor elements are equipped to a part of conducting patterns on insulating substrates of black body, and the other part of the conducting patterns is covered with an insulating layer of black body being nearly the same quality with the substrates. CONSTITUTION:On the upper face of a ceramic substrate 1, the black ceramic substrates 1' being nearly the same quality therewith are arranged, and out of the conducting patterns 2, the part other than the LED adhering faces 9 and the fine metal wire 4 junction parts 10 is covered to about 0.3mm. thickness extending over nearly the whole surface. Accordingly flowing out of the solder material from the LED adhering faces 9 to the wire junction parts 10 can be prevented when assembling is to be performed. Moreover because the conducting faces are protected with ceramics being the same quality with the substrates, peeling off of the protective film itself and crack are not generated, and the visual contrast between the light emitting faces and the circumferential parts thereof is enhanced particularly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat sink for electronic circuits suitable for the construction of semiconductor electronic circuits, particularly hybrid integrated circuits or display devices.

Helagoo for electronic circuits, which has a conductive pattern on an insulating substrate and mounts active elements such as transistors and light emitting diodes, and passive elements such as resistors and capacitors to form hybrid integrated circuits or display devices, is characterized by its structure and materials. From the above point of view, flow control of the adhesive brazing material and means for protecting the conductive pattern surface have always been a problem.

For example, in a ladder for display devices, one of the light emitting diodes is placed on one of the conductive surfaces of the conductive pattern, and the brazing material is placed through it.
A phenomenon that often occurs is that the adhesive brazing material oozes out from the adhesive surface and wets the excess portion of the conductive surface, and attempts to connect the two in series by bonding one of the electrodes of another light emitting diode to this conductive surface often occur. A problem has arisen that makes it virtually impossible.

Furthermore, in ladders for hybrid integrated circuits, a solder plating layer is formed on the conductive surface in order to protect the conductive pattern surface and reduce the resistance value.

In this process, the active semiconductor elements that have been bonded are protected with a precoat and then immersed in a solder bath. Passive elements such as resistors and capacitors can also be fixed at the same time, but the immersion time was too long. In some cases, the solder material soaks into the semiconductor active element through a small gap between the precoat material and the conductive surface, causing a phenomenon in which the bonding thin metal wire is corroded.

In this case, no problem arises in the bonding process, but another obstacle occurs due to the flow of the solder material, and the problem of controlling the flow of the brazing material still remains.

The conventional means of controlling the flow of brazing material have been to strictly control the amount of brazing material, heating temperature, and time. Although it has been considered to apply a low-flow prevention material to create a so-called ``dam'', it has remained a mere proposal because no material that is thermally or chemically suitable for the prevention material has been found, and it is difficult to find an effective solution. Not yet reached.

Furthermore, the method of protecting the conductive pattern surface by providing a solder plating layer on the surface has the problem of corrosion of the conductive pattern material by the solder material, and is not necessarily suitable in terms of materials.

Another proposed means for protecting the conductive pattern surface is to cover the conductive surface with resin or glass by directly utilizing the protection technology for resistive elements in thick film hybrid circuits.

However, resin or glass is not only a material that is inherently susceptible to chemicals, but also has the disadvantage that if the adhesive area is large, the conductive material may peel off or the protective material itself may crack due to the difference in thermal expansion coefficient with the conductive material. It is.

To solve this problem, a protective material with a low coefficient of expansion and chemical resistance can be used to cover the entire surface of the rudder, but glass, for example, has such properties and is a high melting point material, so it reacts with conductive materials and causes resistance. Increasing the value may cause disadvantageous problems such as changing the resistance value of the adjusted resistor in the case of hybrid circuit headers, as is well known, so the material may not be suitable as a protective material for the conductive surface. Gender is not tubularly resolved.

Furthermore, visual contrast with the light emitting surface is important in display devices.

Therefore, for headers for display devices, along with manufacturing technology issues centered on solving the flow control of brazing material and protection means for conductive surfaces, the means to improve this visual contrast is an important issue, and the substrate material is made of black ceramic. has traditionally been used.

However, even if only the temporary substrate is blackened, the conductive pattern itself provided on this surface is not a dark body, so it is difficult to say that the visual contrast between the light emitting diode in the light emitting state and the surrounding area is still sufficient. It is something.

An object of the present invention is to provide an electronic circuit which solves various manufacturing technology problems such as controlling the flow of the repellent brazing material for mounting the semiconductor element and protecting the conductive surface, as well as problems related to improving visual contrast in display devices. An object of the present invention is to provide a structure of a header for use in the present invention and a method of manufacturing the same.

According to the present invention, a conductive pattern formed on an electronic circuit header using a ceramic material as an insulating substrate has a conductive surface that is substantially the same as the insulating substrate, at least between the part where the semiconductor element is to be bonded and the part where the semiconductor element is to be bonded. An insulating layer member formed integrally with the ceramic material is coated,
It is possible to obtain an electronic circuit header in which two parts are physically separated with respect to the flow of brazing material.

According to the present invention, the conductive surface between at least the part to which the semiconductor element is to be bonded and the part to be bonded of the conductive pattern formed on the header for an electronic circuit using a ceramic material as the insulating substrate is black in color, which is almost the same as that of the insulating substrate. It is covered with an insulating layer member made of ceramic material and integrally formed with the ceramic material, and the two parts are physically separated from each other against the flow of brazing material, and the entire surface of the insulating substrate including the conductive pattern becomes a visual dark object. It is possible to obtain a ladder for electronic circuits formed in the following manner.

Further, according to the present invention, a conductive surface of the conductive pattern provided on the sintered or unsintered ceramic substrate at least between the part to which the semiconductor element is to be bonded and the part to be bonded has a non-conductive surface having substantially the same quality as the ceramic substrate. It is possible to obtain a method for manufacturing an electronic circuit header in which a paste-like ceramic material containing sintered ceramic powder as a main component is coated and sintered integrally with a substrate ceramic material.

On the conductive surface of the conductive pattern of the electronic circuit header according to the present invention, at least between the part to which the semiconductor element is to be bonded and the part to be bonded, an insulating layer member made of a ceramic material having substantially the same quality as the insulating substrate is provided. Since the two parts are coated in an integrated state and are physically separated from each other against the flow of soldering material, the flow of soldering material from the semiconductor bonding part to the bonding part can be completely blocked, thereby preventing hybrid accumulation. Assembling work of circuits, display devices, etc. can be made extremely easy.

In addition, the insulating layer member that acts as a dam against the flow of so-called brazing material is made of a ceramic material that is almost the same as the insulating substrate, so the conductive pattern surface is extremely ideal thermally, chemically, and mechanically. In addition to this, the risk of accidents such as peeling off of the conductive surface or cracking of the protective material itself is significantly reduced.

Furthermore, the insulating layer member is made of black ceramic material and the entire surface of the insulating substrate including the conductive pattern is formed into a visually dark body, which can significantly improve the visual contrast when a light emitter is mounted, making it suitable for use in display devices. It becomes suitable as belly fat.

This will be explained in detail below using the drawings.

FIG. 1 is a plan view of a display device assembled on a conventional header for electronic circuits.

In the conventional electronic circuit header, the conductive pattern 2 is formed on the surface of the insulating substrate 10 with all the conductive surfaces 3 exposed, so that the light emitting diodes LED, , LED2...
...LEDn conductive surface 3 according to the display light emission pattern
are arranged on top of each other and mounted respectively.

When it is necessary to connect two light emitting diodes in series, the electrodes of the other light emitting diodes are bonded to the same conductive surface to which one light emitting diode is bonded using thin metal wires 4.

At this time, if the amount of brazing material, heating temperature, time, etc. are not appropriate, the brazing material often overflows from the bonding surface and flows over the conductive surface, excessively wetting the area to be bonded.

Therefore, unless bonding conditions such as the amount of brazing material, heating temperature, and time are strictly controlled, subsequent bonding connections will be impossible.

However, production control that completely satisfies these bonding conditions is difficult, and a decrease in yield cannot be avoided.

Figure 2 is a diagram illustrating a state in which the brazing material has spilled out to the conductive surface to be bonded, and 5 shows the brazing material overflowing from the bonding surface of the light emitting diode LED1 or LED2 onto the respective conductive surface 3. L from LED2 electrode
This indicates that bonding connection cannot be made to the conductive surface to which ED is bonded.

Furthermore, since the conductive surface 3 of the conventional heso-goo for electronic circuits is all exposed, a method for protecting this surface becomes a problem.

In display devices, the entire surface of the insulating substrate containing the light emitting diode is usually covered with transparent resin or glass to protect the conductive surface along with the light emitting diode, but these protective materials are mechanically and chemically weak materials. However, it is difficult to say that the material is necessarily suitable, and the peeling phenomenon of the conductive surface or cracking of the protective material itself due to the unavoidable difference in thermal expansion coefficient between the conductive material or the insulating substrate material. It is difficult to avoid the occurrence of this phenomenon, and it is one of the factors that reduce the reliability of devices.

Furthermore, although the objective of improving the visual contrast between the light-emitting surface and the peripheral area, which is unique to display devices, has been achieved to some extent by using insulating substrate materials and blackening means, the conductive pattern is formed over almost the entire surface of the substrate. The exposed conductive surface itself is optically not a dark body but rather a bright color body, and is relatively dense (concentrated) around the light emitting diode, so that visual contrast around the particularly important light emitter is reduced. is not necessarily good.

Next, in order to assemble a hybrid integrated circuit using a conventional heso-glue for electronic circuits, the required semiconductor active elements are usually adhered to the exposed conductive surface to complete the necessary bonding connections, and then resistive elements, capacitive elements, etc. Passive devices are inserted into respective through holes, and the active semiconductor devices are coated with a precoating material and immersed in a solder bath for a very short time.

This soaking time must be carefully controlled so that it is never too long.

If this time is too long, the solder material will penetrate through the small gap between the precoat material and the conductive surface, corrode the bonding metal wire, and greatly reduce the yield.

Figure 3 shows a partial cross-sectional view of the above-mentioned hybrid integrated circuit which has been eroded and cut by the solder material penetrated by the thin bonding metal wires, and 1, 3 and 4 are the same as the previous one, with an insulating substrate, a conductive pattern and a conductive pattern. 6.7 and 8 represent the semiconductor active element, precoat material and solder material, respectively.

In the case of this hybrid integrated circuit, when immersed in a solder bath, passive elements such as resistive elements and capacitive elements are soldered into respective predetermined through holes, and at the same time, solder material is applied to each exposed conductive surface of the conductive pattern. It is plated to form a surface protection material and also acts to reduce electrical resistance.

However, the solder material has the problem of corroding the conductive material and, like resin and glass, lacks material compatibility as a protective material for the conductive surface.

In conventional electronic circuit headers used for hybrid integrated circuits or display devices, the conductive pattern formed on the surface of the insulating substrate is left with its entire conductive surface exposed. Therefore, the flow of adhesive brazing material cannot be controlled sufficiently.

Also, conductive surfaces cannot be reliably protected. Alternatively, it has many undesirable problems in terms of manufacturing technology, reliability, and added value of the product, such as not being able to satisfy the visual contrast of the display device.

According to the present invention, these problems can be easily solved.

FIGS. 4 and 5 are diagrams showing an example of implementation of the present invention in a display device.

In the header for a display device according to the present invention, the upper surface of the ceramic insulating substrate 1 is an insulating substrate 1' made of a black ceramic material that is almost the same as this substrate material, and among the conductive surfaces of the conductive pattern 2, the light emitting diodes LED, . LED2...
. . . Almost the entire surface is coated in a layer with a thickness of 0.501 to 0.3, except for only the portion 9 where the LEDn is to be bonded and the portion 10 where it is to be bonded.

Therefore, only the portion 9 where the light emitting diode is to be bonded and the portion 10 where each diode is to be bonded using the bonding thin metal wire 4 are exposed, and the entire surface of the insulating substrate including the conductive surface between these two portions is exposed. 1 and is coated with a thin ceramic layer 11 of substantially the same quality as this, so that the flow of the soldering material from the adhesive surface 9 of the light emitting diode to the part 10 to be bonded during assembly is reduced. , can be completely blocked by the ceramic layer 11 in between, and the conductive surface is protected by a ceramic material of the same quality that is thermally, chemically and mechanically strong and has approximately the same coefficient of thermal expansion as the substrate material. It is also possible to prevent peeling of the protective material or cracking of the protective material itself, and almost all problems in manufacturing technology and reliability are solved.

In addition, most of the conductive pattern 2 is covered with black ceramic material and is not exposed like in conventional patterns, so the visual contrast between the light emitting surface and the surrounding area can be significantly improved, increasing the added value of the product. The electronic circuit header according to the present invention is made by forming a required conductive pattern 2 on a sintered or unsintered ceramic insulating substrate 1, and using an unsintered A paste-like ceramic material whose main component is ceramic powder is applied to the entire surface of the substrate, except for the conductive surfaces where semiconductor elements are to be bonded and where bonding is to be performed, and then sintered at a sintering temperature to form the substrate ceramic material. , can be manufactured by integrating and sintering the paste-like ceramic material and the conductive surface of the conductive pattern.

In this case, printing technology is effective as a means of applying the paste ceramic material, and its sintered size is 0.01 except in special cases.
It is appropriate to select ~0.3 mmK.

For example, a specific example of a display device is as follows.

A predetermined conductive pattern 2 is printed on an unsintered ceramic insulating substrate 1 (for example, Al2O3 green tape) with a thickness of 1.5 mm using tungsten paste, and then Fe-Ni-Mn or Patent Application Showa is printed on it using tungsten paste. 47-3099
A paste-like ceramic material mainly composed of Al2O3 powder containing a small amount of a coloring agent such as molybdate or tungstate described in Specification No. Print to a thickness of about 40μ on the entire surface of the insulating substrate, excluding the surface, and
After completing the sintering of the ceramic and the metallization of the conductive pattern in a wet hydrogen gas atmosphere at 0 to 1700°C,
To obtain a heat shield for an electronic circuit according to the present invention suitable for a display device, in which the parts of the conductive pattern 2 other than the conductive surface of the part to which the light emitting diode is bonded and the part to be bonded are covered with a black thin ceramic material layer.

FIG. 6 is a cross-sectional view of one embodiment of the present invention applied to a thick film hybrid integrated circuit.

In this case, the insulating layer member 1' made of a ceramic material of substantially the same quality as the ceramic insulating substrate 1 is used for each conductive part of the part where the semiconductor element 6 is to be bonded and the part to be bonded, as well as the part where passive elements such as resistors or capacitors are baked. It is formed integrally with and coated on the insulating substrate 1 except for the surface thereof.

At this time, setting the height of the insulating layer member 1' to the height of the semiconductor element 6 is extremely effective in preventing short circuit accidents due to contact between the semiconductor element 6 and the bonding thin metal wire 4.

FIG. 7 is a diagram illustrating that the insulating layer member 1' according to the present invention is effective in preventing short-circuit accidents caused by contact between the semiconductor element 6 and the bonding thin metal wire 4.

As explained in detail above, according to the electronic circuit helagoo of the present invention, when semiconductor elements on the same conductive surface of the conductive pattern are bonded, the gap between the parts to be bonded and the part to be bonded is bonded to the base integrated with the ceramic insulating substrate. Since it is coated in layers with a ceramic insulating material that is almost the same as the plate material, it can completely prevent the flow of brazing material from the bonding surface of the semiconductor element to the bonding surface when assembling electronic circuits, making manufacturing control easier and faster. In addition to dramatically improving the accumulation, the conductive direction is covered and protected with a ceramic material that is almost the same as the substrate material, which prevents peeling of the conductive surface and cracking of the protective material itself, greatly improving reliability. can do.

Furthermore, since the coated ceramic material can be easily blackened, the visual contrast of the display device is significantly improved.

Furthermore, it is clear that the practice of the present invention does not limit the use of the transparent epoxy resin 11 mold of FIG. 5 in a display device or the resin 13 protector for the resistor 12 of FIG. 6 in a hybrid integrated circuit. Also, brazing the external lead wire 14 does not interfere with the work.

These conductive surfaces that require brazing need not be coated with paste ceramic material, as is the case with conductive surfaces where semiconductor elements are to be bonded and where bonding is to be performed, making it easier in the manufacturing process. It is something that can be done.

[Brief explanation of the drawing]

Figure 1 is a plan view of a display device assembled on a conventional ladder for electronic circuits, and Figure 2 is a diagram illustrating a state in which brazing material has wetted to the conductive surface to be bonded in a conventional header for electronic circuits. , FIG. 3 is a diagram illustrating a state in which the bonding thin metal wire is eroded and cut by the penetrated solder material, and FIGS. 4 and 5 are one implementation of the present invention when applied to a display device. An example diagram, FIG. 6 is a cross-sectional view of one implementation when the present invention is applied to a thick film hybrid integrated circuit, and FIG. 7 is a diagram showing how the insulating layer member according to the present invention prevents contact short-circuit accidents between semiconductor elements and bonding thin metal wires. It is a figure explaining that it is effective. 1: Ceramic insulating substrate, LED: Light emitting diode, 2
: conductive pattern, 8: solder material, 3: conductive surface of the conductive pattern, 9: conductive surface to which the light emitting diode is to be bonded, 4: thin metal wire for bonding, 10; conductive surface to be bonded, 5: bath-deposited brazing material , 11: transparent epoxy resin, 6: semiconductor element, 12: thin film resistor, 7: precoat material, 13: protective resin for thin film resistor, 14: external lead wire.

Claims (1)

[Claims] 1. A visually dark insulating substrate, a conductive pattern provided on the insulating substrate, a semiconductor element connected to a part of the conductive pattern, and a semiconductor element connected to the other part of the conductive pattern, A semiconductor device comprising a substrate and a dark insulating material of substantially the same quality.