JPS6025291A - Method of producing hybrid integrated circuit board - 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 can be used for electronic circuits that require high-density packaging and high reliability, and is suitable for use in ceramic multilayer hybrid integrated circuits that are easy to mount passive chip components and semiconductor chip components. The present invention relates to a method of manufacturing a substrate.

Conventional Structures and Problems There are conventional methods for manufacturing this type of ceramic multilayer hybrid integrated circuit board as follows. That is, a conductive paste made of a heat-resistant metal powder such as tungsten molybdenum, manganese, etc., alone or in a mixture, is printed as a wiring on a raw ceramic sheet containing alumina powder as the main component, and then an insulating paste of alumina powder is printed as an insulating layer. After repeating the process alternately to create multiple layers,
Batch firing in a reducing atmosphere. Next, the wiring conductors exposed on the surface of the uppermost layer are plated with nickel and gold to obtain a ceramic multilayer wiring board.

In order to have a circuit function, we printed a resistive paste made of a mixture of carbon powder and resin as a passive element.
Baking to form a resistor. Next, passive chip components (
For example, chips (tinop capacitors), mini-mold transistors, etc. are mounted using the solder dip method, solder reflow method, etc., and semiconductor chip components (C, LSI) are connected using the wire bond method, etc.

However, according to this manufacturing method, the above-mentioned heat-resistant metal pastes are all oxidized in an oxygen atmosphere at a high temperature of 400° C. or higher, so a carbon-based resistor is unavoidably used. For this reason, the resistance value fluctuates due to thermal stress during the soldering process for mounting chip components and the like, resulting in a drawback that the resistance value often deviates from the standard in the final inspection.

In addition, the environmental characteristics (heat resistance, humidity resistance, temperature characteristics) of the resistor are not sufficient.
The resistance value change rate after standing for 0 hours is -3.8% to -6.
0% high humidity characteristics (60℃, 96% RH1oooHr resistance value change rate after leaving) is +4.8% to 8.2% Temperature characteristics (
Resistance value change rate between -25℃ and +100℃) is ±460p
pm/°C.

All of these values have a sheet resistance value of 75Ω/Ω to 1
This is for a resistor with a resistance value of 0 to Ω/Ω, and as the resistance value range increases, the above characteristics tend to deteriorate over time.

Which of these drawbacks is a constant problem with resistors made of carbon powder and resin? In the case of heat resistance, this is due to curing shrinkage of the resin, and in the case of moisture resistance, it is due to moisture absorption.

This is due to swelling.

However, one of the major drawbacks of the conventional manufacturing method is that the wire bonding (connection using gold wire) of semiconductor chip components requires
It is necessary to apply expensive gold plating to the top layer wiring of the board,
In order to ensure bonding connection reliability, a thickness of 1.6 μm or more is usually required using the electrolytic plating method, and a plating lead-out wiring is required for electrolytic plating.
The unnecessary area of the board increases, resulting in fewer chips and lower board costs.

It had the disadvantage that it became high.

On the other hand, in the electroless plating method, 3. A thickness of 0/Jm or more is required, which also has the disadvantage of increasing the substrate cost.Objective of the Invention The object of the present invention is to provide a hybrid integrated circuit in which a highly reliable printed resistor is formed. It is an object of the present invention to provide a method for manufacturing a hybrid integrated circuit board using lamic multilayers, which reduces the cost of the board and facilitates the mounting of semiconductor chip parts and the like.

Structure of the Invention To achieve this object, the present invention provides a circuit board in which a printed resistor is formed on a ceramic multilayer wiring board that is integrally sintered in a reducing atmosphere, and a circuit board for plating with a desired circuit pattern. After printing an active paste having a metal core, it is fired to form a plating core, and then electroless plating is performed on the top of the plating core to form a plated conductor.

Note that the surface wiring lead-out hole of the ceramic multilayer wiring board needs to be filled with an oxidation-resistant conductor, such as platinum, palladium, rhodium, or iridium alone or in an alloy. As a result, a highly reliable printed resistor can be formed on a conventional reducing atmosphere sintered ceramic multilayer wiring board. However, as a printed resistor, the commonly used ruthenium oxide resistor is effective. For the lower electrode of this resistor, a single substance or an alloy of silver, palladium, or all-platinum is effective.

As a plating conductor, single-layer plating or multi-layer plating of copper, tin, solder, nickel plating, etc. is particularly effective in terms of cost and solderability.

This plated conductor is a circuit conductor and a connection electrode for passive chip components, semiconductor chip components, etc. 0 Description of Embodiments The present invention will be described below based on embodiments according to the manufacturing process.

(1) As a ceramic material, the main component is alumina,
Silica, Magne 7A, etc. were added, and an alumina slurry was kneaded with polyvinyl butyral resin as a binder resin, diptyl phthalate as a plasticizer, and isopropyl alcohol as a solvent, and then kneaded into a film to form a raw alumina sheet.

(2) Next, as shown in Fig. 1, a paste-like conductor 2 containing a single or a mixture of heat-resistant metals such as tungsten, molybdenum, and manganese is printed in a desired wiring pattern on the raw alumina sheet 1 using a screen printing method. and dried.

(3) Next, as shown in Fig. 2, the above raw alumina sheet 1
An insulating paste-like insulator 3 made of the same material as above was printed in a desired pattern by screen printing and dried.

(4) Next, as shown in Figure 3, the above (2) + (3
) were repeated alternately to form internal wiring conductors 2 and internal wiring conductors 4 which also served as through-hole conductors on the raw alumina sheet 1, and surface wiring extraction holes 6 in the uppermost layer insulator 5.

(6) Next, as shown in Fig. 4, the surface wiring hole 6 is filled with an oxidation-resistant metal paste conductor 7 made of platinum, palladium, rhodium, or a mixture of platinum, palladium, rhodium, and iridium by screen printing method, and then placed in a reducing atmosphere. The conductor, insulator, and raw sheet were sintered into one piece by heating to 1520°C.

There were no pinholes in the surface wiring holes of the ceramic multilayer wiring board thus obtained.

(6) Next, on the ceramic multilayer wiring board thus obtained, as shown in FIG. An electrode pattern was printed using a screen printing method and heated to 850° C. in an oxidizing atmosphere to obtain an electrode.

(7) Next, as shown in FIG. 6, ruthenium oxide powder, lead borosilicate glass, ethyl cellulose as a resin, and butyl carbitol acetate as a solvent were added to the top of the electrode obtained in (6) above, and mixed. The dispersed resistor paste was screen printed in a desired resistance pattern and heated to 68° C. in an oxidizing atmosphere to form a resistor 9.

(8) Next, as shown in FIG.
980P40) into the desired wiring pattern and heated to 480°C in an oxidizing atmosphere to form plating nuclei 10
was formed.

(9) Next, this was immersed in a copper sulfate plating solution to form a copper-plated conductor 11 by an electroless method. This was used as a connection electrode for passive chip components and semiconductor chip components, and this was used as a substrate for a ceramic multilayer hybrid integrated circuit.

For reference, FIG. 8 shows a state in which a ceramic chip carrier on which a multilayer chip capacitor 12 and a semiconductor chip (IC) 13 are mounted is mounted on the ceramic multilayer hybrid integrated circuit substrate using a solder reflow method.

When we measured the environmental characteristics of the printed resistor formed on the hybrid integrated circuit board obtained in steps (1) to (9) above, we found that the sheet resistance value was within the range of 15Ω/unit to 850Ω/(). , heat resistance property (after standing at 120℃, 1000Hr) is 0.12
%-0,38%, moisture resistance (60'C95%RH, 10
After 00Hr standing) is 0.04-0.21%, temperature characteristics (
-26°C to +100°C) is ±280 ppm/°C, and the characteristics are significantly improved compared to those using conventional carbon-based resistors.

Effects of the Invention As described above, the manufacturing method according to the present invention enables low-cost plating conductor formation on a circuit board on which a highly reliable printed resistor is formed, and moreover, it can be performed using an electroless plating method. Due to its simplicity and large number of chips, it has the effect of significantly reducing board costs. In addition, in the case of conventional manufacturing methods, manufacturers of multilayer wiring boards
Since the system requires the user to process the product after the gold plating process or the resistor forming process, it takes a long time (30 to 45 days) to change the wiring pattern. With the same image as the state (without wiring), only the pattern for the plated conductor needs to be changed, which has the effect of speeding up response to design changes.Furthermore, passive chip components, semiconductor components, etc. can be mounted at the same time. This also has the effect of reducing assembly man-hours.

[Brief explanation of drawings]

Figures 1 to 7 are cross-sectional views showing the manufacturing process of a hybrid integrated circuit board according to an embodiment of the present invention, and Figure 8 is a cross-sectional view showing the manufacturing process of a hybrid integrated circuit board obtained according to the present invention, with passive chip components and semiconductor components mounted on the hybrid integrated circuit board obtained according to the present invention. It is a sectional view showing a state. 1... Alumina raw sheet, 2, 7.8... River...
Conductor, 3.5... Insulator, 4... Internal wiring conductor, 6... Surface wiring hole, 9... Resistor, 10... ... Plated core, 11 ... Copper plating conductor, 12 ... Multilayer chip capacitor,
13... Semiconductor chip. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] After printing an active paste with a metal core for plating in a desired circuit pattern on a circuit board in which a printed resistor is formed on a ceramic multilayer wiring board that is integrally sintered in a reducing atmosphere, it is fired. 1. A method for manufacturing a hybrid integrated circuit board, comprising forming a plating core, and then performing electroless plating on the top of the plating core to form a plated conductor.