JPS63173092A - Protection of chip part carrying 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 [Field of Industrial Application] The present invention relates to a method for protecting chip components mounted on a substrate such as a liquid crystal display device by covering the chip components with a resin.

[Conventional technology]

5 and 6 show conventional examples, FIG. 5 is a cross-sectional view of a liquid crystal display device equipped with a conventional flip chip, and FIG. 6 shows the entire flip chip in FIG.
FIG. 3 is a partial sectional view showing a state covered with. In FIG. 5, 1 is a lower glass substrate constituting the liquid crystal display device, 2 is an upper glass substrate, and 3 is a flip chip (chip component) mounted on the glass substrate 1. This flip chip 3 is made of epoxy resin. It is covered by the tree [14].

Next, using FIG. 6, the glass substrate 1 of the flip-deep 3
This section explains how to install and protect the product.

First, an ITO pattern 5 is formed on a glass substrate 1, and a conductive metal such as Cr, Cu, Au, etc. is deposited on this ITO pattern 5 by electroless plating or vapor deposition.
Form one layer or multiple layers, and apply 7lux or cream solder on top. Next, the solder bump 7 formed on the bottom surface of the flip chip 3 is placed facing the ITO pattern 5 so that the temperature reaches 200°C to 350°C. ;
In gas is supplied to the flip tube 3.

As a result, the preliminary Ia solder on the flip dip 30, solder bump 7, and glass substrate 1 is melted while softening the thermal WJ impact on the glass substrate 1, and the flip chip 3 is attached onto the glass substrate 1 via this melted solder. . next,
Epoxy resin 4, which is liquid at room temperature, is dropped onto flip chip 3 and cured by heating in a high temperature bath. At this time, the epoxy resin 4 used has a high viscosity so as not to flow out onto the plate surrounding the flip chip. In this way, the flip chip 3 is covered and protected with epoxy paulownia IIf4.

[Problem that the invention seeks to solve]

However, in the conventional protection method described above, since the epoxy resin 4 has a high viscosity, the I1 between the flip chip 3 and the glass substrate 1 is
Epoxy 41 and resin 4 could not be sufficiently penetrated and buried in the first gap, which caused problems in environmental resistance, especially moisture resistance.

[Means for Solving the Problems] The present invention provides a method for protecting chip components mounted on a board, in which the chip components mounted on the board are coated with resin. After applying the resin to form the opening, the board is placed in a vacuum chamber, the air in the m gap between the board and the chip components is exhausted through the opening, and then the pressure is returned to atmospheric pressure (12!). infiltrating the resin into the gap;
Furthermore, in this method of protecting chip components mounted on a substrate, 81111 is dropped onto the chip component to coat the entire chip component, and then the m-lipid is heated and cured.

(Function) Since the resin is injected into the gap between the substrate and the chip component by the vacuum injection method, the resin easily penetrates into this gap and can be completely buried. Furthermore, since the periphery of the chip component is covered with resin, the entire chip component can be completely covered with Si resin.

(Example) Hereinafter, the present invention will be explained based on FIGS. 1 to 4.

FIG. 1 is a partially enlarged view showing the state in which epoxy resin 9 is applied around the flip chip according to the present invention, and FIG.
3 is a sectional view showing the state in which the epoxy resin 9 is permeated from the vacuum state in FIG. 2 to atmospheric pressure, and FIG. FIG. 2 is a cross-sectional view showing a state in which the epoxy resin 10 is coated with the epoxy resin 10. FIG.

Incidentally, the same members and similar parts as those of the conventional example shown in FIGS. 5 and 6 are given the same numbers, and their explanations will be omitted.

First, as shown in FIGS. 1 and 2, an epoxy resin 9 is applied to a flip chip three-circumferential plate so as to form an opening 8 in a part of its periphery. Next, liquid crystal display v4 cod vacuum 41
(not shown) is placed in a vacuum state, and the air in the gap between the glass substrate 1 and the flip-deep 3 is discharged to the outside through the n-port 8.

This brings the gap into a vacuum state. After that, when the inside of the vacuum chamber is returned to atmospheric pressure, the epoxy resin 9 is released due to the difference between the IIWA in a vacuum state and atmospheric pressure as shown in FIG.
It penetrates into the gap between tJ records. Next, the liquid crystal display device is taken out of the vacuum chamber, and as shown in FIG. 4, epoxy resin 9110 is dropped onto the top surface of the flip chip 3 to cover the entire flip chip 3. Finally, add epoxy resin 9.10 to 120°C.
Heat and harden in a high temperature bath for 2 hours. In this way, the flip chip 3 is sealed with epoxy resin 119.10.
and protect.

The above epoxy resin 9.10 is said to have the same viscosity,
The viscosity is 30. Goo~100.000 cp.

As described above, since the flip chip 3 can be completely protected with the epoxy resin 9.10, environmental resistance such as moisture resistance is improved.

In addition, as described above, epoxy resin 9 is added using the vacuum injection method.
Since the epoxy resin 9 permeates into the li gap between the glass substrate 1 and the 7-lip chip 3, the epoxy resin 9 permeates in a short time, and the workability is further improved compared to the conventional method.

In this embodiment, epoxy resin was used, but not only epoxy resin but also thermosetting resins such as phenol resin and silicone resin can be used.

(Effects) As described above, according to the present invention, chip components can be completely sealed and protected with resin, so environmental resistance such as moisture resistance is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged view showing the state in which epoxy resin vR9 is applied around the flip chip according to the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. 4 is a sectional view showing a state in which the epoxy resin 9 is infiltrated at atmospheric pressure due to poor air penetration condition, FIG. 4 is a sectional view showing a state in which the entire flip chip in FIG. 3 is coated with epoxy resin 10, and FIG. FIG. 6 is a cross-sectional view of a liquid crystal display device equipped with a conventional flip chip, and is a cross-sectional view showing a state in which the entire flip depth in FIG. 5 is covered with epoxy resin vB4. 1...Glass plate, 3...Flip chip (chip parts), 4.9.10...Evo 4 Niji 11 fat, 8...
·Aperture. Patent applicant: Alps Electric Co., Ltd. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a method for protecting chip components mounted on a board, in which the chip components mounted on the board are coated with resin, resin is applied around the chip components on the board so as to form an opening in a part of the periphery, and then the board is removed. The air in the gap between the substrate and the chip component is evacuated through the opening in a vacuum layer, and then the pressure is returned to atmospheric pressure to allow the resin to penetrate into the gap, and the resin is then dropped onto the chip component to cover the entire chip component. A method for protecting chip components mounted on a board, which comprises heating and curing these resins.