JP2002190556A - Automotive control and control unit and manufacturing method - Google Patents

Abstract

(57) [Problem] To provide a control unit for a vehicle in which a circuit board on which an IC chip is mounted is reduced in size and connection reliability is improved. A vehicle control control unit mounted on a case, wherein a vehicle control semiconductor IC chip such as a microcomputer, an operational amplifier, and a logic is electrically connected to and mounted on a conductor pattern of a circuit board.
The chip has heat dissipating means, and the circuit board and the semiconductor IC
An automotive control and control unit electrically connected by a plurality of bumps formed on the chip electrode surface side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile control control unit (an engine control control unit, an AT control control unit, an AT control control unit, or a throttle chamber mounted in an engine room or a vehicle interior) in which a semiconductor IC chip provided with heat dissipation means is directly mounted. Motor control unit, air conditioner control unit, etc.) and its manufacturing method.

[0002]

2. Description of the Related Art As a conventional technology for mounting a semiconductor IC chip (hereinafter simply referred to as an IC chip), a device for mounting in a vehicle interior (-30 to + 85 ° C., 4.4G specification) uses a resin-based printed circuit board. Therefore, mounting by QFP and SOP packages has been adopted.

In addition, an engine room interior wearing device (-4)
(0-125 ° C., 20 G specification), a bare chip (Au wire bonding connection) mounting is adopted on a thick film hybrid integrated circuit board using a ceramic substrate.

In the latter, by applying a silicon gel or the like to a circuit board, the reliability such as deterioration of insulation resistance of solder connection portions and conductor gaps and prevention of migration are improved. In addition, since the above-mentioned prior art is generally well-known, illustration of a well-known example etc. is omitted.

In a method of mounting an IC chip on a circuit board via an interposer, an Au bump is attached to the IC chip, and the IC chip is electrically connected to the surface of the interposer on which the Au conductor pattern is formed by heating and pressing. There is a method of connecting the back surface of an interposer in which solder bumps are formed on a conductor pattern to a multilayer circuit board by solder reflow.

Further, among the interposers, there is an interposer in which an Au conductor pattern is formed only on the surface, an IC chip is attached with an adhesive, and electrical connection is made by Au wire bonding.

[0007] Those technologies are PGA, BGA, CSP
There is also a packaged product applied to such packaged products.

[0008] Interposer specification (BGA, CSP)
As a prior art, Japanese Patent Application Laid-Open No. H08-125062 discloses an insulating substrate having a circuit pattern, mounted on a first surface of the insulating substrate, and electrically connected to the circuit pattern by an Au wire bonding wire. A semiconductor element, a resin sealing portion that seals a part of the insulating substrate and the semiconductor element, and a plurality of conductive elements arranged in a matrix on the second surface of the insulating substrate and electrically connected to the circuit pattern. Having a solder ball, the plurality of solder balls have at least a first solder ball group, and a second solder ball group having a different height from the first solder ball group and the insulating substrate. A semiconductor device is disclosed.

Japanese Patent Application Laid-Open No. 7-176684 describes a circuit pattern connected by through holes.
An interposer having first and second surfaces, and a stiffener base having an input / output unit connected to a circuit pattern of the interposer, wherein first and second surfaces of the interposer have first and second surfaces. A second semiconductor chip is mounted and connected to the circuit pattern, the stiffener-based input / output unit is connected to an external circuit, and the circuit pattern has a bonding pattern connected to a terminal of the semiconductor chip, a through hole, The semiconductor chip composed of an internal transmission pattern for connecting the bonding pattern, a through hole connected to the input / output unit of the stiffener base, and an external transmission pattern for connecting the bonding pattern is formed by wire bonding or TAB. A semiconductor device mounted on an interposer is described.

[0010] In addition, there are the following control devices mounted in the engine room of an automobile.

An aluminum wire bonding arrangement between a waterproof connector and a ceramic substrate is disclosed in Japanese Patent Application Laid-Open No. H11-86933.
Discloses a case-integrated waterproof connector structure disclosed in
No. 0-3753, and the structure of the gel frame is described in JP-A-11-145338.

[0012]

Conventionally, an IC chip (bare chip) used in an automobile control control unit, for example, an engine control control unit mounted in an engine room, is directly mounted on a circuit board via a conductive adhesive. It was mounted and electrically connected to the circuit board by Au wire bonding.

As described above, since the IC chip is directly electrically connected and mounted on the circuit board by Au wire bonding or the like, (1) man-hour required for connection, (2)
Yield in substrate assembly process, (3) IC chip mounting area, (4) Connection reliability between substrate and chip, (5)
There has been a problem with, for example, the testability of individual IC chips.

Further, the engine control unit is mounted in the engine room, and it is required to reduce the influence of a rise in the temperature of the IC chip in taking these measures.

In the field of semiconductor substrate technology, the mounting printed circuit board is made compact by mounting an I / O chip on the front side of an interposer having through holes and mounting a CPU chip on the back side. Has been proposed. It has also been proposed to mount a solder ball on the back surface of the interposer.

However, such a technique cannot be immediately applied to an engine control unit mounted in an engine room. The structure must be suitable for the engine control unit, especially for mounting in the engine compartment.

An object of the present invention is to provide a control unit for an automobile (for example, an engine control unit) suitable for mounting in an engine room, to reduce the size and cost of the circuit board, to improve the connection reliability, and to assemble the board. It is an object of the present invention to provide a control control unit for an automobile mounted with an IC chip capable of improving the yield and reducing the total cost of the vehicle, and a method of manufacturing the same.

[0018]

The gist of the present invention to achieve the above object is as follows.

[1] An automobile control and control unit mounted and mounted on a case, wherein a semiconductor IC chip for automobile control such as a microcomputer, an operational amplifier, and logic is electrically connected to and mounted on a conductor pattern of a circuit board. The control control unit for an automobile is characterized in that the chip has heat dissipating means and is electrically connected to the circuit board by a plurality of bumps formed on the electrode side of the semiconductor IC chip.

[2] Semiconductor IC with Au bump formed
In a method for manufacturing a control control unit for an automobile for electrically connecting a chip and an Au conductor of a circuit board,
The u-bump is substantially spherical and is arranged in the same shape as the substrate for electrical characteristic inspection. The semiconductor IC chip is mounted on the substrate for electrical characteristic inspection to inspect electrical characteristics. A method of manufacturing a control unit for a vehicle, wherein the control unit is mounted on a pattern portion and then fixed.

Here, an engine control unit will be described as an example.

By mounting and connecting a plurality of IC chips directly to a circuit board, the manufacture thereof is facilitated and the size of the board is reduced.

Among the IC chips used for engine control, the heat-generating power ICs are mounted on the circuit board in one or more units. The heat-generating power system is divided into a non-power system and a heat-generating power system. In particular, the heat-generating power system is separated from the non-power system and collected into one place (the non-power system is also collected as much as possible) to form 1 to 4 groups. As a result, heat is easily dissipated, and the effect of heat on the non-power IC chip can be reduced.

A plurality of IC chips are arranged in a sealed case, and 1 to about 30 IC chips are directly mounted and connected to a circuit board in order to enable mounting in an engine.

For mounting in the engine, 125 ° C.
However, an engine control unit that has no effect is required. In order to suppress the partial temperature rise by the engine control unit itself within 20 ° C, the IC chip is separated from the heat-generating power system and the non-power system, and the heat-generating power system is provided with a means of heat dissipation or heat transfer. Mounted on the circuit board.

An IC chip on which an Au bump is formed by an Au bump bonder is mounted on an inspection substrate, and an electrical characteristic test is performed. The IC chip that has passed the inspection is used for assembling the control unit.

According to the present invention, an Au bump is formed on an Au conductor pattern portion on a circuit board having a small shrinkage error composed of two to ten low-temperature fired glass ceramic substrates by using an Au bump bonder. Connect IC chip,
Mount.

The Au bumps are used for connecting and mounting the IC chip on a circuit board, and also have a function for mounting on an inspection substrate for inspecting electrical characteristics of the IC chip.

A fine conductor Ag-Pt + Ni + Au plating (minimum conductor width: 0.04 mm, minimum gap: 0.04 mm) is formed on the surface of the circuit board by a photo-etching method or a printing method, and an IC chip having an Au bump bonder is mounted thereon. Crimping is performed with an ultrasonic thermocompression device or a thermocompression device, and electrical connection between the substrate and the chip is performed. Note that no overcoat glass is formed on the IC chip mounting portion of the ceramic substrate which is a circuit substrate.

The ratio of the maximum diameter of the Au bump to the height of the bump during thermocompression bonding is preferably 1.5 to 8 in order to improve the connection reliability. Further, underfill is applied and cured to improve connection reliability.

The heat dissipation means of the semiconductor IC chip includes:
Heat dissipating means consisting of heat dissipating fins or heat conducting members
Formed on a chip. The radiating fins are fixed by an adhesive layer made of an organic resin, for example, a silicon-based or epoxy-based resin, and the heat conductive member is made of an organic resin, for example, an adhesive layer made of a silicon-based or epoxy-based resin.
It is fixed between the aluminum base provided above the chip and below the substrate.

As the circuit board, a low temperature fired glass ceramic multilayer substrate, a high temperature fired alumina multilayer substrate, or a high heat resistant glass epoxy multilayer substrate is used.

Further, the circuit board is partially or entirely covered with an organic resin, for example, an epoxy resin (underfill), on the IC chip on which the Au bumps are formed. Further, the circuit board can be covered with a silicone gel and installed in a case, and particularly, can be directly mounted in an engine room or an engine.

The Au bump for electrically connecting the IC chip on which the Au bump is formed and the Au conductor pattern of the circuit board is formed in a substantially spherical shape and substantially the same shape as the electrical characteristic inspection surface. The electrical characteristics can be inspected by directly mounting it on the inspection substrate.

According to the present invention, there is provided an automobile control and control unit which can be mounted in an engine room (including a vehicle interior), for example, an engine control and control unit.
It can be applied to an AT control control unit, a throttle chamber motor control control unit, an air conditioner control control unit, and the like.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an embodiment of an engine control unit will be described with reference to the drawings. FIG.
FIG. 2 is a schematic diagram illustrating a configuration of an engine control unit.

The engine control unit 1
A case 2 and a case-integrated connector 3 are provided. The case 2 includes a ceramic substrate 5 (six layers) and an aluminum base 9 serving as a base thereof.

An electronic component 6 is provided on the ceramic substrate 5 and a connector (not shown) of the case-integrated connector 3.
The ceramic substrate 5 and the ceramic substrate 5 are connected by Al bonding 4, and the power bump 7 on the aluminum base 9 and the ceramic substrate 5 are connected by Al bonding 8. This configuration is a conventionally known technique.

The present invention is characterized by a connecting means for connecting the IC chip (including heat dissipating means) mounted on the ceramic substrate 5 to the ceramic substrate 5. That is, as shown in FIG.
The IC chip 11, the IC chip 12, and the like are ceramic substrates 5.
And fixed. The details of the heat dissipation means of the IC chip will be described later.

An engine control unit 1 is constructed by electrically connecting an IC chip such as a microcomputer, an operational amplifier, and a logic for engine control to a conductor pattern of a circuit board (the ceramic substrate 5 in FIG. 1). .

In arranging the IC chips, the heat-generating power system is separated from the non-power system and integrated into one place. The non-power system is also grouped into one to four places. By arranging the same kind of IC chips close to a certain extent, the number of steps of thermocompression bonding can be reduced.

The heat-generating power IC chips of 0.8 W, 1 W, 2 W, and 3 W are made of a heat conducting member (described later).
The heat can be dissipated to the ceramic substrate 5 and the aluminum base 9 via.

The heat-generating power IC chip is mounted on the ceramic substrate 5 as far as possible from other non-power ICs. By doing so, 1 to 30 IC chips can be provided on the ceramic substrate 5. Thus, all the IC chips are arranged on the ceramic substrate 5.

FIG. 2 is a schematic sectional view in which the IC chip 11 is mounted on a circuit board (ceramic substrate 5). The IC chip 11 includes AU bumps 23, Au, Ni, Ag-Pt.
It is mounted on the ceramic substrate 5 via the layer 24 and fixed by thermocompression, thermocompression or ultrasonic thermocompression.

Around the upper side surface of the ceramic substrate 5, there are provided protrusions 29 for preventing resin from dripping when an underfill is formed. Between the IC chip 11 and the ceramic substrate 5, for example, an epoxy resin is used. The layer (underfill 30) is filled and cured, and the IC chip 11 is securely fixed to the ceramic substrate 5. The ratio of the maximum diameter / height of the AU bump 23 is set to 1.5 to 8.

The ceramic substrate 5 has a multilayer structure of 6 to 12 layers. If the target IC chip is a heat-generating power system, the structure is as shown in FIG. FIG.
FIG. 2 is a schematic sectional view in which an IC chip is mounted on a circuit board.

FIG. 3A shows an example in which an Al radiating fin 41 is mounted on the IC chip 11 and the radiating fin 41 is fixed to the IC chip 11 by a silicon-based or epoxy-based adhesive layer 42 to generate the IC chip 11. It is configured to dissipate heat.

FIG. 3B shows a case where the power consumption is high, in which a heat conducting member 43 is formed instead of the radiation fin. The heat conductive member 43 is made of a silicon-based or epoxy-based adhesive layer 4.
The IC chip 11 and the ceramic substrate 5 are fixed to the IC chip 11 and the ceramic substrate 5, respectively. Thereby, the heat generated by the IC chip 11 is transferred to the ceramic substrate 5 via the heat conducting member 43.

FIG. 3C shows an IC with higher power consumption.
With a structure suitable for using a chip, the heat conducting member 43
Is fixed to the IC chip 11 and the aluminum base 9 by silicon-based or epoxy-based adhesive layers 44 and 45, respectively, whereby the heat dissipation can be further enhanced.

As described above, the temperature rise in the engine control unit 1 can be suppressed to 125.degree.

In order to suppress a partial temperature rise due to the heat generating system power IC to, for example, 20 ° C. or less, it is desirable to employ a heat dissipating means such as a radiation fin 41 or a heat conducting member 43. Thereby, the clearance with respect to the allowable rise temperature can be eased.

FIG. 4 shows a different type of IC chip 12 (a), 12 (b), 1 such as a standard logic IC or an operational amplifier.
FIG. 2C is a schematic cross-sectional view in which 2 (c) is released from the heat-generating power IC and placed on and fixed to the ceramic substrate 5.

The mounting method is the same as that shown in FIG. 2. By mounting a plurality of IC chips to a certain extent on the ceramic substrate 5, assembly becomes easier (reduction in the number of steps of thermocompression bonding).

An Au bump is formed on an IC chip, mounted on a dedicated substrate, and the electrical characteristics are inspected. Defective products can be eliminated before assembling. And is effective in improving the yield.

FIG. 5 is an example of a schematic sectional view of the ceramic substrate 5. The ceramic substrate 5 is composed of a multilayer substrate. In this case, the low-temperature fired glass ceramic substrate of seven layers is formed using green sheets 61 to 66. Each layer of the substrate includes an Au, Ni, Ag-Pt layer 24 and an Ag-P
A VIA conductor 67 connecting to the t layer 25 is formed.

FIG. 6 is a plan view showing an example of a conductor pattern of an IC chip mounting portion of the ceramic substrate 5. Au, Ni, Ag-P arranged at predetermined intervals in the peripheral region of the substrate
A t conductor 24 is provided.

FIG. 7 is a flow chart showing an example of a manufacturing process of the ceramic substrate shown in FIG. 2 or FIG. Step S1
Through 1 to S14, the assembly of the IC chip + Au bump formation is performed. That is, Au is applied to the IC chip (S11).
Au bumps are formed using a bump bonder (S1
2) Do it. Then, the heights of the Au bumps are aligned (S13) to improve the flatness. At this stage, the electrical characteristics of the IC chip are inspected (S14). Only IC chips that pass the inspection are stored, and defective products are eliminated.

On the other hand, solder printing (S2) is performed on the ceramic substrate (S1), and the electronic components are chip-mounted (S3).
The electronic component is fixed by solder reflow (S4). After cleaning the substrate (S5), the IC chip (S
14: Mount Au bumps and pass inspections) (S
6) Thereafter, thermocompression bonding or ultrasonic thermocompression bonding (S7) is performed.

Next, underfill filling and curing (S8)
To improve the connection reliability between the ceramic substrate and the IC chip. Then, a ROM check write (S9) is performed,
High-temperature baking (S10) and intermediate electrical property test (S10)
By performing 11), the substrate assembly is completed (S12).

The finished product assembled as described above is shown in FIG.
As shown in (2), the IC chip package is protected by the gel 71, the cover 72 is adhered to the case 2, and the engine control unit 1 is completed.

FIG. 9 is a side view in which the completed engine control unit 1 is connected and installed at four points on an intake manifold 81 in an engine room. Incidentally, 82 is the engine body, 83 is the injector, 84
Indicates a distributor.

[0062]

According to the engine control unit of the present invention, the IC chip on which the Au bumps are formed is directly mounted on the circuit board, and furthermore, the heat dissipating means is arranged in the case. Enables mounting and reduces the size of the circuit board (smaller IC chip mounting area due to the elimination of Au wire bonding), improves connection reliability, saves labor in the board assembly process, and improves the yield (IC chip single item inspection) Possible).

In particular, when the size of the IC chip is 6 mm square and the number of pins is 144, or when the size of the IC chip is 10 to 11 mm square, the number of pins is 2
An IC chip having a large number of bumps per unit area, such as 56, is usually difficult to mount on a substrate having a thick film printing, for example, a conductor width of 0.2 mm and a conductor gap of 0.2 mm by an Au wire bonding method. According to the present invention, mounting can be easily performed.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an engine control unit according to the present invention.

FIG. 2 is a schematic sectional view in which an IC chip is mounted on a circuit board.

FIG. 3 is a schematic cross-sectional view of an IC chip mounting substrate having heat radiation and heat conduction means.

FIG. 4 is a schematic sectional view in which different types of IC chips are mounted and fixed on a ceramic substrate.

FIG. 5 is a schematic sectional view of a ceramic multilayer substrate (circuit board).

FIG. 6 is a plan view showing an example of a conductor pattern of an IC chip mounting portion of a ceramic substrate.

FIG. 7 is a flowchart showing an example of a manufacturing process of the ceramic substrate shown in FIGS.

FIG. 8 is a schematic sectional view of an engine control unit.

FIG. 9 is a side view of an intake manifold in an engine room equipped with an engine control unit.

[Explanation of symbols]

1 ... engine control unit, 2 ... case,
3: Case integrated connector, 4, 8: Al bonding, 5: Ceramic substrate (circuit board), 6: Electronic component,
7 ... power lab bumi, 9 ... aluminum base, 11, 12 ...
IC chip, 23: Au bump, 24: Au, Ni, A
g-Pt layer, 25: Ag-Pt layer, 29: anti-sagging projection, 30: underfill, 41: Al radiating fin, 4
2, 44, 45: Silicon or epoxy adhesive layer, 4
Reference numeral 3 represents a heat conductive member, 67 represents a VIA conductor, 61 to 66 represent a green sheet, 71 represents a gel, 72 represents a cover, 81 represents an intake manifold, 82 represents an engine body, 83 represents an injector, and 84 represents a distributor.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 7/20 (72) Inventor Shuji Eguchi 2520 Oji Takaba, Hitachinaka City, Ibaraki Prefecture Hitachi, Ltd. Within the equipment group (72) Inventor Tohru Yoshida 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term in Hitachi, Ltd. Production Engineering Research Laboratory F-term (reference) RR10

Claims (10)

[Claims] An automobile control control unit mounted and mounted on a case, wherein a semiconductor IC chip for vehicle control such as a microcomputer, an operational amplifier, and logic is electrically connected to and mounted on a conductor pattern of a circuit board. A control control unit for an automobile, comprising: a heat dissipating means; and electrically connected to the circuit board by a plurality of bumps formed on the electrode side of the semiconductor IC chip. 2. The control unit for an automobile according to claim 1, wherein the connection means for connecting the circuit board and the semiconductor IC chip is an Au bump formed on the semiconductor IC chip and an Au conductor pattern on the circuit board. 3. The control unit for an automobile according to claim 2, wherein a ratio of a maximum diameter / height of the Au bump is 1.5 to 8. 4. The heat dissipating means is composed of a heat radiating fin or a heat conductive member, the heat radiating fin is fixed on the semiconductor IC chip by an organic resin adhesive layer, and the heat conductive member is a semiconductor IC chip by an organic resin adhesive layer. 2. The control system according to claim 1, wherein the heat conductive member is fixed between the aluminum base provided on the semiconductor IC chip and below the ceramic substrate by an organic resin adhesive layer. unit. 5. The semiconductor IC chip is divided into a heat-generating power system and a non-power system, and the heat-generating power system is separated from the non-power system into one place, and the non-power system is grouped into one to four places. The control unit for a vehicle according to claim 1. 6. The control unit according to claim 1, wherein the circuit board is a low-temperature fired glass ceramic multilayer substrate, a high-temperature fired alumina multilayer substrate, or a high heat-resistant glass epoxy multilayer substrate. 7. The vehicle control and control unit according to claim 1, wherein said semiconductor IC chip is partially or entirely covered with said circuit board by an organic resin. 8. The semiconductor IC chip according to claim 1, wherein said semiconductor IC chip is covered on said circuit board by silicon gel, mounted on a case, and directly mounted on a vehicle interior, an engine room or an engine. 3. The control unit for a vehicle according to claim 1. 9. A method for manufacturing a control unit for an automobile, wherein the semiconductor IC chip on which an Au bump is formed and an Au conductor of a circuit board are electrically connected, wherein the Au bump is substantially spherical and has the same shape as the substrate for electrical characteristic inspection. And mounting the semiconductor IC chip on a board for testing electrical properties to test electrical properties, and then mounting the semiconductor IC chip on an Au conductor pattern portion of the circuit board and then fixing the automobile. Of the control unit for the control. 10. The circuit according to claim 9, wherein after mounting the semiconductor IC chip on the Au conductor pattern portion of the circuit board, the semiconductor IC chip is electrically connected to the circuit board by thermocompression bonding or ultrasonic thermocompression bonding. Manufacturing method of automotive control and control unit.