JPH0426240B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method of manufacturing a hybrid integrated circuit board on which circuit element chips are mounted, and a method of coating the circuit element chips with a resin material. Conventional configuration and its problems The surface of the circuit board of a hybrid integrated circuit device containing electronic components such as resistors and capacitors is coated with a resin material, but this resin material is thin and Moreover, it is essential that it be adhered uniformly. However, when the shapes of the elements are complex and diverse, such as circuit boards with tantalum electrolytic capacitors, composite parts, or hybrid circuit boards with semiconductor elements mounted, it is difficult to apply a thin, uniform coating. Furthermore, unless the content of the filler mixed into the resin material is kept below 30% by weight, it will not withstand normal thermal shock cycles in the range of -65°C to +150°C. On the other hand, if a large amount of filler is included in the coating resin,
It is effective in imparting low expansion/contraction change rate characteristics with respect to temperature changes, but in order to use it as a powdered resin, it is difficult in the powdering process, and the gelation time and viscosity have to be adjusted. It is difficult to obtain an appropriate value, and due to the combination of these factors, non-uniform areas of the resin coating (for example, areas where "sagging" or "staining" has occurred) are likely to occur. Therefore, if such a non-uniform portion exists, there is a problem in that cracks occur due to thermal shock cycles and moisture resistance deteriorates significantly. Purpose of the invention The present invention has good compatibility with fillers, and
By using a resin composition that can be easily powderized, pre-curing it, painting it on a circuit board on which circuit element chips are mounted, and then heat-treating it, the problems seen in the above-mentioned conventional example are solved. The present invention provides a stable and reliable coating technology for circuit boards mounted with circuit element chips using a resin material. Structure of the Invention To summarize, the present invention provides a circuit board on which circuit element chips are mounted, a powdery epoxy resin having a filler content of 35 to 70% by weight, and an aromatic amine in an amount approximately equivalent to the powdery epoxy resin. A powdered resin compounded with Adduct as a curing agent is precured at a temperature lower than the curing temperature of the powdered resin, and the precured powdered resin is applied to a circuit board on which circuit element chips are mounted. This is a method for manufacturing a hybrid integrated circuit, in which the surfaces of the circuit board and the circuit element chips are coated with resin by heat-treating the coated powdered resin material, whereby the circuit element chips, For example, to stabilize a semiconductor chip,
Enables reliable coating treatment. DESCRIPTION OF EMBODIMENTS The present invention will be described in detail below with reference to illustrated process diagrams. As the epoxy resin component 1, bisphenol A type epoxy known under the trade name 828 manufactured by Ciel Chemical Co., Ltd. is used, and as the filler 2, anhydrous silica known under the trade name Aerosil is used in an amount of 35 to 70% by weight.
The mixture is weighed and mixed within the range of 1, and then the blending step 3, the kneading step 4, and the grinding step 5 are carried out. Next, as the aromatic amine adduct 6, which is a curing agent, H-84 (trade name, manufactured by Nippon Gosei Kako Co., Ltd.) is blended in approximately the same amount as the epoxy resin component 1, and further, a fourth adduct, which is a curing accelerator, is added. The phosphonium salt 7 is mixed in an appropriate amount in the range of 1 to 1.5% by weight with respect to the mixture of the epoxy resin component 1 and the aromatic amine duct 6.
Then, the mixture that has undergone a remixing step 8, a repulverization step 9, a sieving step 10, and a precuring step 11 is applied to the surface of a hybrid circuit board 12, and a series of heating adhesion steps 13 and resin curing steps 14 are performed. Through the process, the resin coating process is completed and a resin coated circuit board 15 is obtained. In order to apply powdered resin thinly and uniformly to the surface of a hybrid circuit board, it is easy and practical to sprinkle the powdered resin on the heated circuit board in advance. . moreover,
This coating resin layer is then heat-cured in a heat-curing oven at 150°C for 10 to 30 minutes to approximately
It becomes a 200 μm coating layer. In addition, the preliminary curing step 11 in the figure is to leave it standing for about 10 to 30 hours at a temperature of 35 to 50°C, which is lower than the curing temperature of the resin. During this time, the filler and resin components become compatible. make things better. It also degasses and prevents bubbles from forming within the cured product.
Suppression is also effective. Furthermore, this preliminary curing step is also effective in reducing variations in gelation time and viscosity. As an example, a semiconductor IC chip (2.6mm x 3.2
Two chip capacitors (1.6 mm A hybrid circuit board with a structure in which 10 pieces (height 2.0 mm) are lined up and adhered to the wiring conductor part with silver paste is used, and the powdered resin compound is coated on both sides and finished by heat curing. Performance test results showed significantly higher performance than conventional products in terms of heat shock resistance and high temperature and humidity resistance. The following table shows, as an example of the present invention, the amount of filler added is selected as (A) 70% by weight, (B) 50% by weight, and (C) 35% by weight, and the temperature cycle test and This is the result of measuring the pressure test (PCT) at atmospheric pressure and 121℃.
Each of these measured values is, for example, equivalent to the performance value of a conventional resin-sealed semiconductor device. As a comparative reference example, an epoxy resin obtained according to standard specifications for epoxy resin containing an acid anhydride curing agent is used, and 30% by weight of Aerosil (anhydrous silica) as a filler is added to this. .

[Table] Effects of the Invention According to the present invention, since a powdered resin material whose main ingredient is a powdered epoxy resin with a filler content of 35 to 70% by weight is used, conventional products with a filler content of 30% by weight or less are used. It is possible to form a resin coating with excellent thermal shock resistance and high temperature and humidity resistance compared to powdered resin materials.
Moreover, in the present invention, the filler content is 35 to 70
Since the aromatic amine adduct is blended as a curing agent in the weight percent of the powdered epoxy resin in an approximately equal amount, the thermal softening temperature of the powdered resin material becomes high and the electrical properties are stabilized. Furthermore, when a phosphonium compound is blended as a curing accelerator, the curing speed can be made constant. Further, the present invention includes a step of pre-curing such a powdered resin material at a temperature lower than its curing temperature. This preliminary curing step can improve the compatibility between the filler and the resin component, promote degassing, and reduce variations in gelation time and viscosity. Therefore, according to the method of manufacturing a hybrid integrated circuit board of the present invention, the surface of the circuit board and the circuit element chips mounted thereon can be covered with a uniformly thin, uniform, and stable resin coating. .

[Brief explanation of drawings]

The figure is a process diagram showing an example of the present invention. 1... Epoxy (raw material), 2... Filler, 6...
...Curing agent, 7...Curing accelerator, 12...Hybrid circuit board, 15...Resin coated circuit board.

Claims (1)

[Scope of Claims] 1. A powdered resin material prepared by blending a powdered epoxy resin with a filler content of 35 to 70% by weight and an aromatic amine adduct in an amount approximately equal to the amount of the powdered epoxy resin as a curing agent, Precuring at a temperature lower than the curing temperature of the powdered resin material, coating the precured powdered resin material on a circuit board on which circuit element chips are mounted, and then heat-treating the coated powdered resin material, A method for manufacturing a hybrid integrated circuit board, characterized in that the surfaces of the circuit element chip and the circuit board are coated with a resin. 2 Powdered epoxy resin with filler content of 35 to 70% by weight, blended with aromatic amine adduct in approximately the same amount as the above powdered epoxy resin as a curing agent, and further blended with a phosphonium compound as a curing accelerator. The resin material is precured at a temperature lower than the curing temperature of the powdered resin material, the precured powdered resin material is coated on a circuit board on which circuit element chips are mounted, and then the coated powdered resin material is cured at a temperature lower than the curing temperature of the powdered resin material. 1. A method for producing a hybrid integrated circuit board, which comprises heat-treating the product and coating the circuit element chips and the surfaces of the circuit board with a resin.