JPS62249431A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To avoid failure caused by temperature cycle and improve reliability by a method wherein a sealed part is coated with insulating resin by lapped coating. CONSTITUTION:After the surface of a ceramic substrate 3 on which a bare chip 6 and electronic parts 7 and 8 are mounted and fixed is dipped in solution 9 of phenolic resin which has a thermal expansion coefficient almost same as that of the substrate 3, the adhereing phenolic resin is cured. After that, the surface of the substrate 3 is dipped in the phenolic resin solution 9 again to be coated by lapped coating. Then, after the whole substrate 3 is dipped in the phenolic resin solution 9 and the front and back surfaces of the substrate 3 are coated with the phenolic resin, the adhering phenolic resin is cured and the substrate 3 is again dipped in th phenolic resin solution 9 to be sealed by a mass 1 of the resin formed by lapped coating. With this constitution, even if a severe temperature cycle test is carried out, large thermal stress is not created between the substrate 3 and the sealing resin 1 so that failures such as breakdown at the connecting parts of the electronic parts 7 and 8 or crackings in the substrate 3 can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device and a method for manufacturing the same, and particularly to a technology that is effective when applied to a manufacturing technology for hybrid integrated circuit devices.

[Conventional technology]

The casting method (Cas) is used as one of the packages for semiconductor devices.
ting). Regarding this casting method,
For example, "Electronic Materials J, published by Kogyo Research Association, March 1973.
Monthly issue, published March 1, 1970, listed on pages 48 to 54. This document states that there are casting methods that use a case and casting methods that do not use a case. As one of the sealing methods using a case,
A method is described in which a resin is poured into the case and a desired portion is sealed within the case. In addition, casting methods that do not use a case include the dropping method, in which a certain amount of resin is dropped onto the element surface to form a hardened layer, the dipping method, in which the entire element is immersed in resin liquid and then cured after being taken out, and semi-cured resin powder. After pre-forming into a tablet shape and placing it on the surface of the element, it is placed in a heating furnace? 8. There is a melt casting method where the material is melted and hardened.

[Problem that the invention seeks to solve]

In a hybrid integrated circuit device having a casting package structure using a case, a hybrid integrated circuit board made of ceramic that is housed in the case and covered with an encapsulating resin such as silicone resin has its front and back surfaces overcoated with phenol resin. , bare chips fixedly mounted on the front and back surfaces,
Electronic parts etc. are protected. Further, the board is supported by the case at several support points.

However, when a hybrid integrated circuit device with such a structure is subjected to a severe temperature cycle test ranging from -5560 to +150'C, cracks occur in the board due to the difference in thermal expansion coefficient between the board and the encapsulating resin. The inventor has revealed that there are cases where electronic components or the like are electrically broken at their fixed parts.

Further, in a hybrid integrated circuit device using a case, it is difficult to reduce the outer diameter of the pan cage because of the case.

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable hybrid integrated circuit device that is resistant to blistering caused by temperature cycling, and a method for manufacturing the same.

Another object of the present invention is to provide a technique that can manufacture small-sized hybrid integrated circuit devices.

The above and other objects and novel features of the present invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Means for solving problems]

In manufacturing the hybrid integrated circuit device of the present invention, the front and back surfaces of the hybrid integrated circuit board, on which bare chips and electronic components are fixedly mounted, are first adjusted to have a coefficient of thermal expansion approximately equal to that of the substrate. After immersing the substrate in a phenol resin liquid having a coefficient of thermal expansion of , the substrate is pulled up to harden the adhered phenol resin, and then the surface of the substrate is immersed in the phenol resin liquid again to perform overlapping coating of phenol resin.

Next, after the surface coating of the substrate is completed, the entire substrate is immersed in a phenol resin solution, and the front and back surfaces of the substrate are coated with phenol resin. After this coating, the substrate is lifted out of the phenol resin solution to cure the adhered phenol resin, and the substrate is immersed again in the phenol resin solution to seal the front and back surfaces of the substrate with the resin lump formed by overlapping coating.

[Effect]

According to the above-described means, bare chips and electronic components on the front and back surfaces of a substrate made of ceramic are sealed with a phenol resin having substantially the same coefficient of thermal expansion as that of the ceramic. Therefore, even if a severe temperature cycle test is performed, no large thermal stress will be applied between the board and the sealing resin, and damage to the connection parts of the board crank, electronic components, etc. will not occur. In addition, since the phenol resin constituting the sealing resin forms a resin mass through layered coating, the bare chip and electronic components are reliably covered, and the sealing properties of the sealing resin are stable. Furthermore, since the sealing resin is formed by overlapping coating of phenol resin, the volume of the sealing portion is smaller than that of sealing using a case, and the hybrid integrated circuit device can be miniaturized.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the external appearance of a hybrid integrated circuit device according to an embodiment of the present invention, and FIGS. 2 to 6 are views showing the sealed state of the hybrid integrated circuit device, and FIG. A cross-sectional view showing only the surface of the substrate immersed in the phenol resin solution, Figure 3 is a cross-sectional view showing the board being pulled up from the phenol resin liquid, and Figure 4 is a cross-sectional view showing the board being completely pulled up from the phenol resin liquid to reveal the adhered phenol. A cross-sectional view showing a state in which the resin is dried; FIG. 5 is a cross-sectional view showing a state in which the entire board is immersed in a phenol resin solution and the back side of the board is also sealed;
FIG. 6 is a cross-sectional view showing a state in which the substrate is pulled up from the phenol resin liquid and the phenol resin is dried.

In this embodiment, an example in which the present invention is applied to a hybrid integrated circuit device will be described.

As shown in FIG. 1, the hybrid integrated circuit device manufactured in accordance with this embodiment has a structure in which a plurality of glues 2 protrude from a resin block (package) (2) formed by overlapping coating. This hybrid integrated circuit device has leads 2 protruding from both sides of the resin ingot, and these leads 2 are all bent in the same direction, making it a so-called dual in-line type device.

Next, a method of manufacturing such a hybrid integrated circuit device, particularly a puff caging method, will be explained with reference to FIGS. 2 to 6.

First, as shown in FIG. 2, a workpiece 4 having leads 2 attached to both sides of a substrate 3 is prepared.

The substrate 3 in this work 4 is made of ceramic such as alumina, although it is not particularly limited. The thermal expansion coefficient α of this substrate 3 is 7×10 −′/deg. Further, although not shown, a bare chip or a resistor is provided on the surface (principal surface) of the substrate 3. The electrodes of the bare chip and the corresponding wiring on the substrate 3 are electrically connected by wires. Note that in the drawings, these bare chips, wires, etc. are covered with an overcoat film 5. This overcoat film 5 has a thermal expansion coefficient α of 6. 5 x 10-6/d e g, and is made of phenol resin, which has a coefficient of thermal expansion substantially equal to the coefficient of thermal expansion of the substrate 3). Although not shown, the wires may fall down when the board 3 is handled, resulting in a short circuit, or
Or, this is to prevent the wire from getting caught and breaking. Further, the back surface of the substrate 3, that is, the lead 2
On the extending side, there is a chip resistor 6. chip capacitor 7,
It is equipped with electronic components such as ultra-small transistors 8.

Next, as shown in Fig. 2, such a work 4
is lowered and immersed in a phenol resin solution 9 contained in a tank (not shown). At this time, since the workpiece 4 is held by clamping the lead 2 portion, and since it is desired that at least the phenol resin does not adhere to the lead 2 tip end portion, the workpiece 4 is directed upward. And the surface of the substrate 3,
That is, the side on which the overcoat film 5 is provided is immersed in the phenol resin liquid 9. In this case, the phenol resin liquid 9 is not applied to the back surface of the substrate 3 yet.

Next, as shown in FIG. 3, the workpiece 4 is rotated to the left as shown by the arrow and raised. At this time, if a large amount of the phenol resin liquid 9 partially remains on the back surface of the substrate 3 and swells up, that is, when resin sag occurs, the lower end of the substrate 3 is
slowly pull it up so that it comes into contact with the liquid surface, and remove the excess phenol resin liquid 9 using its own weight.

Next, as shown in FIG. 4, the workpiece 4 is rotated half a turn above the tank containing the phenol resin liquid 9, so that the substrate 3 becomes horizontal, and the phenol resin liquid adheres to the surface of the substrate 3. Dry 9. During this drying process, when a film is formed on the surface of the attached phenol resin solution 9, in other words, about 1/2 to 1/3 of the resin surface is covered with mold hyphae. When the white discoloration is visible, the drying time during this period is approximately 60 seconds, and as shown in Figure 2, the surface side of the workpiece 4 is immersed in the phenol resin solution 9 again. At this time, the surface of the substrate 3 is first immersed in the resin,
After drying, it is covered with a coating film 10, as shown in FIG. Then, by dipping the substrate surface into the phenol resin liquid 9 for the second time, the phenol resin liquid will adhere to the surface of the coating film 10 again. Therefore, the overcoat film 5 and the unillustrated wiring and resistors are covered with a coating film formed by dipping into the phenol resin solution 9 twice.

Next, the back side of the substrate 3, that is, the chip resistor 6
．． The surface on which the chip capacitor 7, ultra-small transistor 8, etc. are mounted is coated. During this coating, the entire substrate 3 of the work 4 is immersed in the phenol resin liquid 9, as shown in FIG. Also,
During this immersion, the work 4 is swung so that the phenol resin liquid 9 uniformly contacts the entire front and back surfaces of the substrate 3. At this time, the phenol resin liquid 9 covers the back surface of the substrate 3 and the electronic components mounted on the back surface, and also covers the coating film 10 on the front surface of the substrate 3.

Next, the workpiece 4 is lifted out of the phenol resin solution 9 and rotated to dry it in a state where the substrate 3 is horizontal, that is, in a state as shown in FIG. 6. In addition,
When lifting the workpiece 4 from the phenol resin liquid 9, if the resin sag as described above occurs, return the excess phenol resin liquid 9 to the tank as shown in Fig. 3 and remove the workpiece 4. pull up.

Next, as shown in FIG. 6, after the entire front and back surfaces of the substrate 3 have been covered with the coating film 10 and the resin surface has been cured as described above, the workpiece 4 is
As shown in FIG. 5, the substrate 3 is immersed in a phenol resin solution 9, and the phenol resin solution 9 is again applied to the front and back surfaces of the substrate 3, and then pulled out and cured.

In this way, by coating the front surface of the substrate 3 four times and the back surface twice, the front and back surfaces of the substrate 3 of the workpiece 4 are covered with the resin mass (package) 1 made of the coating film 10 by overlapping coating.

In this way, coating the front surface of the substrate 3 in the workpiece 4 before coating the back surface ensures reliable sealing, since if the front and back surfaces of the substrate 3 are coated at the same time, coating may not be performed reliably depending on the location. This is for the purpose of stopping. Further, the surface of the substrate 3 is coated a total of four times in order to reliably seal the bare chip (bare arch knob). Also, the back side of the board 3 is coated two times less than the front side, but this is because the electronic component to be coated is a single component that has already been packaged, and the sealing is done in this way. This is because the coating is applied to the connection portion with the wiring layer of the electronic component and the wiring layer, and a sufficient sealing effect can be obtained with two coatings.

According to such an embodiment, the following effects can be obtained.

(1) According to the present invention, the front and back surfaces of a board on which bare chips and electronic components are mounted are sealed by overlapping coatings of phenol resin having a coefficient of thermal expansion approximately equal to that of the board. Thermal stress due to the difference in thermal expansion coefficients is not applied to the substrate or fragile bare chip, resulting in the effect of lengthening the life of the hybrid integrated circuit device during temperature cycle tests.

(2) According to the above (1), according to the present invention, it is possible to obtain the effect that the characteristics of the hybrid integrated circuit device are stabilized.

(3) According to the above (1), according to the present invention, since sealing is performed by layered coating, the package size can be reduced compared to the conventional casting method using a case, and the size of the hybrid integrated circuit device can be reduced. The effect is that it is possible to achieve For example, when using a case, the package dimensions are 29.5 mm wide, 55.5 mm long, and 7 mm thick, but with the layered coating according to the present invention, the pan case dimensions are 27.0 to 23 mm wide.
7Qmm, length 51.17~53. OOmm.

It is small with a thickness of 3.19 to 4.99 mm.

(4) According to (1) above, according to the method for installing a hybrid integrated circuit device according to the present invention, there is no need to prepare a case for packaging, so it is possible to reduce the sealing cost. Effects can be obtained.

(5) According to the above (4), according to the present invention, there is no need to manage the case for sealing, and work management is also facilitated.

(6) As a result of (1) to (5) above, the present invention provides a synergistic effect in that a highly reliable small-sized hybrid integrated circuit device that operates stably even under temperature cycles can be provided at a low cost. Effects can be obtained.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. In other words, even if the number of times of coating for sealing is greater than that of the embodiment described above, the same effect as that of the embodiment described above can be obtained. Moreover, other resins may be used as the sealing resin.

In the above explanation, the invention made by the present inventor is mainly applied to the field of application, which is the pancaging technology of dual in-line hybrid integrated circuit devices, but the invention is not limited thereto. , for example, can be similarly applied to puff caging technology for single-line hybrid integrated circuit devices.

The present invention is applicable to at least sealing technology including packaging technology for electronic components.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

In manufacturing the hybrid integrated circuit device of the present invention, for a substrate made of ceramic on which bare chips and electronic components are fixedly mounted, the surface of the substrate is first heated to a thermal expansion coefficient that is approximately the same as the coefficient of thermal expansion of the ceramic substrate. After overcoating with a phenol resin liquid having a coefficient of The parts will be reliably sealed.

In addition, since the sealing resin block is made of phenol resin, which has approximately the same coefficient of thermal expansion as ceramic, there is a large thermal stress between the substrate and the sealing resin even when subjected to a severe temperature cycle test. will no longer work, and damage to the connection parts of circuit boards, electronic components, etc. will no longer occur. Since the sealing resin is formed by overlapping coatings of phenol resin, the volume of the sealing portion is smaller than that of sealing using a case, and the size of the hybrid integrated circuit device can be reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the external appearance of a hybrid integrated circuit device according to an embodiment of the present invention; FIG. 2 is a cross-sectional view showing a state in which only the substrate surface is immersed in a phenol resin solution during connection of the hybrid integrated circuit device; Figure 3 is a sectional view showing the state in which the substrate is pulled up from the phenol resin solution, Figure 4 is a sectional view showing the state in which the board is completely pulled up from the phenol resin solution and the attached phenol resin is dried. Similarly, FIG. 6 is a cross-sectional view showing a state in which the entire board is immersed in a phenol resin liquid and the back side of the board is also sealed. FIG. 6 is a cross-sectional view showing a state in which the board is lifted from the phenol resin liquid and the phenol resin is dried.

Claims (3)

[Claims] 1. A method for manufacturing a semiconductor device, comprising sealing a portion to be sealed by overcoating the portion to be sealed with an insulating resin. 2. Manufacturing a semiconductor device according to claim 1, characterized in that the front and back surfaces of the hybrid integrated circuit board are sealed with a resin lump by coating the front and back surfaces of the hybrid integrated circuit board with an insulating resin. Method. 3. The method is characterized in that the front surface of the hybrid integrated circuit board is overcoated with an insulating resin and sealed with a resin block, and then the back side of the hybrid integrated circuit device is overcoated with an insulating resin and sealed with a resin block. Claim 1
A method for manufacturing a semiconductor device according to section 1.