KR100388279B1 - Substrate of embedded element for high frequency application - Google Patents

Abstract

The present invention relates to a method for manufacturing an MCM-C module component, and more particularly, by manufacturing an MCM-C module component using active devices such as FETs, transistors, diodes, and passive devices, thereby reducing the number of MCM-C processes. The present invention relates to a passive circuit board for high frequency of MCM-C module parts, which can provide cost reduction and high density of products.

Conventionally, pads and capacitors (capacitors) on the top surface form parasitic capacitance values, which makes it impossible to implement accurate capacitance values in circuits, and this structure causes unwanted noise at high frequencies in the GHz band used in the communicator. There was a problem.

The present invention to solve the above problems,

In the lower part of the MCM-C module component which is manufactured by laminating a ceramic substrate containing passive elements such as resistors and capacitors, and combining an active element component such as a transistor in the upper portion,

It is characterized in that the pad formed on the upper surface of the ceramic substrate for the signal input and output of the active device component in a structure using a common capacitor and a capacitor.

Therefore, according to the present invention, in the manufacture of MCM-C module components, the active elements and the capacitors can be simultaneously implemented to reduce the space, and the density and size of the modules can be reduced, and the layer required for manufacturing the internal devices can be achieved. Since the number can be reduced, it is possible to reduce the raw material cost and the cost of the process, which can greatly contribute to lowering the price of the product and improving productivity.

Description

Substrate of embedded element for high frequency application of MMC-C module components

The present invention relates to a method for manufacturing an MCM-C module component, and more particularly, by manufacturing an MCM-C module component using active elements such as FETs, transistors, diodes, and passive elements, thereby reducing the number of processes of the MCM-C module. The present invention relates to a passive circuit board for high frequency of MCM-C module parts, which can provide cost reduction and high density of products.

In general, a multi chip module (hereinafter referred to as MCM) refers to a surface-mounted semiconductor bare chip having a different function on one wiring board.

MCM arranges a semiconductor bare chip such as a CMOS LSI on a wiring board, and fills and packages a resin by potting between the chip and the chip or between the chip and the board, and greatly depends on the type of the wiring board material to be surface-mounted. MCM-L, MCM-C, MCM-D is divided into three.

MCM-L is a module using a multilayer printed wiring board usually made of glass and epoxy resin, and has a merit that the wiring density is not so high and the production cost is low.

The MCM-C is based on a ceramic (alumina or glass ceramic) that forms a multilayer wiring using thick film technology, and is similar to a thick film hybrid IC using a multilayer ceramic substrate.

MCM-D is a thin film technology that forms a copper (Cu) thin film wiring layer, a polyamide insulating layer, etc., and connects a flip chip connected to ceramic (alumina or aluminum nitride) or silicon or aluminum on which a multilayer wiring is formed. It is characterized by the highest wiring density and high production cost.

As described above, the MCM-C technology combines an active device and a passive device to implement a module, and has an advantage of manufacturing lightweight, high-density components as compared to the existing HIC technology.

Meanwhile, a passive element is implemented inside the ceramic and an active element is formed thereon, and a specific method for an efficient arrangement for the active element and the passive element is not known.

Glass-Ceramic dielectric material is used as a material for manufacturing the ceramic substrate including the internal element, and a ceramic sheet having a thickness of 50 μm and 118 μm is manufactured by using a tape casting method.

In order to manufacture a product using the MCM-C technology, a ceramic lamination process is used.

1. Blanking Process

; The green tape is cut into blanks using a precision blanking die. The die cuts the tape at the same time and punches the hole.

Since there is a difference in shrinkage between the vertical direction and the horizontal direction of the tape casting, in order to obtain a uniform shrinkage rate, each layer is laminated alternately at 90 °.

2. Via Forming

; An electrode passing through each substrate and penetrating the upper and lower surfaces is a "via", and forming a small hole in the ceramic green sheet to form such a via is a via forming process.

The inner diameter of the via required is between 125 and 400 μm, and fine holes of about 80 to 100 μm are possible.

Vias are made by methods such as Die Set Rigid Punch Arrays, CNC Punching Machines, drills, and laser machining.

The Rigid Punch Array method, made by combining several punches into one, is a suitable method for manufacturing a large capacity at one time, and it is possible to form several holes at once.

The methods of punching are determined by the speed of moving the x-y work table and the movement time of the punch jig, and the general punching speed is 102-103 pieces / sec.

3. Printing Process

; As a method of realizing the wirings and L, C, and R passive elements embedded in the ceramic substrate, a printing process is a process of implementing a paste-type material by a screen printing method.

The printing process may be a process of printing a circuit pattern or filling vias with conductor electrodes.

The precision of this printing process depends not only on the characteristics of the paste material used as the circuit electrode, but also on the screen mesh size, the snap-off between the screen and the printing object, the printing pressure, the printing speed, and the squeeze strength.

Printing on substrates to form via-filling with conductors is also called thick film metallization.

Thick Film Paste is composed of Conductive Phase, Vehicle, Binder and Additives.

① Conductive Phase-The phase of the conductor consists of a metal phase. W, Mo / Mn is used in high-temperature calcined ceramics, and Ag, Au, Cu, Ag-Pd, Pt-Au, etc., are used in low-temperature calcined ceramics.

The conductive metal phase is composed of metal particles of less than 5㎛, occupies 50 ~ 70w / o of the total content of the paste, the particle size distribution and shape affects the final conductivity and physical properties of the paste.

② Inorganic Binder-Inorganic Binder is composed of glass of low melting point to improve adhesion and densification with substrate, and the amount of binder occupies 10 ~ 20wt% of paste.

Bonding with the substrate uses three methods: frit bonding, flux bonding and reactive bonding.

Via Fill paste is similar to conductive paste, but has high solid content and high viscosity at the same time.

In the case of the conductive paste, the viscosity is 200 Pa.s, while the paste for Via Filling has a value of 2000 to 3000 Pa.s.

4. Lamination Process

; It is a process of laminating | stacking several sheets of thick film printing on a press die, and heating and integrating more than the glass transition temperature of a binder.

Die wall is also used to prevent lateral deformation of sheets during lamination.

During the lamination process, the microstructure of the green sheet changes with composition, and the spatial distribution of the pores changes during the lamination process.

Pore is removed as a function of pressure and time used, and the amount of pore removal affects the shrinkage rate after firing.

5. cutting

; A cutting process is a process of cutting a process integrated into a lamination to a desired size of a specimen.

For good cutting, the cutting is performed by heating at a temperature equal to or higher than the Tg of the organic material present in the green sheet.

Various cutting tools and methods are used for cutting such as hot razor, steel rule die, dicing saw, and laser scribing.

6. Binder Burn-Out and Firing Process

; Since LTCC is fired at a low temperature, a belt furnace for thick film paste can be used. In the manufacturing process, burn-out and firing are generally performed separately.

Burn-Out gradually raises the temperature up to 350 ℃ when the material of the conductor is Ag, Au, and 550 ℃ when it is Cu.The burn-out is Ag, Au at this temperature to remove the plasticizer and organic matter in the laminate and paste. In the case of 1 hour, in the case of Cu, keep for about 5 to 6 hours.

After removal of the binder, the laminate is brittle, so it is moved using an alumina setter with care in handling.

Glass / Ceramic laminates using Ag and Au electrodes were fired in a belt furnace at 850 ° C for 30 minutes.

As described above, the circuit pattern of the passive element including the passive element and the conductor electrode is printed on the ceramic green sheet by the printing process, and the firing resistors (R), inductors (L), and capacitors (C). A passive element substrate portion is fabricated in which passive elements such as the back are included.

The module product is completed by placing an active element on the passive element substrate. As shown in FIG. 1, a schematic view of the completed module component includes a ceramic substrate 10 having a passive element therein, and an active element component on the upper side. It consists of the part in which 20 is placed.

Inductors, resistors 11, and capacitors 12 elements are located on the ceramic substrate 10 having the passive elements embedded therein. Product is implemented.

On the other hand, active element components 20 such as transistors 21 are used for the oscillator and amplifier modules used at high frequencies, and these active element components 20 are often used simultaneously with the capacitor 12 elements.

2 is a sectional view applied when manufacturing such a module by MCM-C.

For the signal input and output of the transistor 21, which is the active element component 20, a pad 40 for inputting and outputting signals should be formed on the upper surface of the ceramic substrate 10, and space arrangement as shown in FIG. 2 is generally attempted. .

At this time, the capacitor 12 embedded in the ceramic substrate 10 has a structure in which the pad 40 is connected in close proximity.

Therefore, as described above, due to such a structure, a parasitic capacitance value is formed between the pad 40 and the capacitor (capacitor) 12 on the upper surface, and thus it is impossible to implement an accurate capacitance value in the circuit.

In addition, such a structure has a problem of causing unwanted noise in the high frequency of the GHz band used in the communication device.

Therefore, the present invention was devised to solve the above-described problems, and by manufacturing the MCM-C module components using active elements and passive elements such as FETs, transistors, diodes, etc., shortening the number of processes of MCM-C It is an object of the present invention to provide a high-frequency passive element embedded substrate of MCM-C module parts, which enables cost reduction and high density of products.

High frequency passive element embedded substrate of the MCM-C module component of the present invention for achieving the above object,

In the lower part of the MCM-C module component which is manufactured by laminating a ceramic substrate containing passive elements such as resistors and capacitors, and combining an active element component such as a transistor in the upper portion,

It is characterized in that the pad formed on the upper surface of the ceramic substrate for the signal input and output of the active device component in a structure using a common capacitor and a capacitor.

1 is a schematic diagram of a conventional general MCM-C module,

2 is a cross-sectional view of FIG. 1;

3 is a cross-sectional view of a high frequency passive element embedded substrate of the MCM-C module component according to the present invention;

4 is an implementation circuit diagram to which the present invention is applied.

<Description of the symbols for the main parts of the drawings>

10: ceramic substrate with passive elements (inductor, resistor, capacitor)

20: active element component 30: lead wire

11: resistance 15: capacitor

15a: Capacitor and pad combined pattern 21: Transistor

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 3, in the MCM-C module component according to the present invention, as shown in FIG. 3, a ceramic substrate having passive elements such as a resistor 11 and a capacitor 15 is stacked thereon, and an upper portion thereof. In the MCM-C module component manufactured by combining active device components such as transistor 21, the pad 15a formed on the upper surface of the ceramic substrate for signal input / output of the active device component is a passive element capacitor ( Manufactured in common with 15).

In the high frequency passive element embedded substrate of the MCM-C module component of the present invention configured as described above, the resistor 11 and the capacitor 15 elements are first placed on the ceramic substrate 10 having the passive element disposed thereon. Place the conductive wire 30 inside for the connection.

On the other hand, an active element component 20 such as a transistor 21 is used on the upper portion, and these active element components 20 are often used simultaneously with the capacitor 15 element.

A pad to be formed on the upper surface of the ceramic substrate 10 for the signal input and output of the transistor 21, the active element component 20, is manufactured by a capacitor and a pad combined pattern 15a.

Therefore, the structure of the capacitor and the pad combined pattern 15a which use the pad of the active element component 20 and the capacitor 15 which is a passive element embedded in the ceramic substrate 10 in common is used.

At this time, the capacitor and pad combination pattern 15a has a structure exposed to the upper surface of the capacitor 15, and thus it is possible to attach the transistor 21, which is the active element component 20, by laser trimming or the like. It is also possible to change the dose value.

In addition, by reducing the number of laminations for forming pads for inputting and outputting signals on the upper surface of the ceramic substrate 10, lamination processes such as punching and printing required for module development may be reduced.

Therefore, the space can be reduced and the size of the module can be reduced. As a result, it is possible to reduce the process work required for manufacturing the module product and to reduce the cost, thereby greatly contributing to the improvement of productivity.

The present invention produced as described above is applicable to the production of high-frequency module components such as a voltage controlled oscillator (VCO), an output amplifier (PAM) and the like used in a mobile phone.

4 is a circuit diagram showing a configuration of a VCO module applicable to the present invention. As shown in FIG. 4, contact points designated as 15a as contact portions of a transistor and a capacitor, which are active element components, are applicable according to the present invention.

As described in detail above, the high-frequency passive element embedded substrate of the MCM-C module component according to the present invention can be spatially reduced by simultaneously implementing an active element and a capacitor in manufacturing the MCM-C module component. Higher density and miniaturization are possible, and the number of layers required to manufacture internal devices can be reduced, thereby reducing raw material costs and process costs, which can greatly contribute to lowering product prices and improving productivity. It works.

Although the invention has been described in detail only with respect to the specific examples described, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

Claims (1)

In the high frequency passive element embedded substrate of the MCM-C module component manufactured by combining a ceramic substrate of a high frequency passive element with a capacitor formed on one side and a ceramic substrate having an integrated circuit or an active element, The two ceramic substrates are aligned and coupled such that a portion of the capacitor formed on one side of the ceramic substrate of the high frequency passive element is exposed to one side of the ceramic substrate on which the integrated circuit or the active element is formed; The capacitor is a high-frequency passive device embedded substrate of the MCM-C module component, characterized in that exposed to the position that can be electrically connected to the pin of the integrated circuit or active element formed on the ceramic substrate.