JPH04206683A - Manufacture of printed circuit board - Google Patents

Abstract

PURPOSE:To prevent the fused solder to flow into the other section from an electrode region by forming a solder dam consisting of a resistance material at a boundary between the electrode region and the other section of conductor pattern at a time of forming a resistance material pattern. CONSTITUTION:A conductor pattern 2 is formed on the surface of a ceramic substrate 1. Next, a resistance material pattern is formed. In this case, a solder dam 6 consisting of a resistance material film is simultaneously formed at the boundary between an electrode region 4 and a wiring region 5 in the conductor pattern 2. Thereafter, a cream solder 7 is mounded on the electrode region 4. A part 8 is mounted on the electrode region 4 on which the solder 7 is mounded and the soldering is done by the reflow process.

Description

[Detailed Description of the Invention] [Objective of the Invention] <Industrial Application Field> The present invention involves forming a conductor pattern having an electrode region on the surface of a substrate, applying solder to the electrode region, and attaching parts, etc. by reflow. The present invention relates to a method of manufacturing a wiring board to which a wiring board is soldered.

<Prior art> Conventionally, in hybrid ICs and the like, a conductor film is formed in a desired pattern on the surface of a substrate made of ceramic or the like, a resistor film is further formed, and the electrode area of the conductor pattern is printed, for example. A method of manufacturing a wiring board is used in which solder is applied using a method of soldering, and components and the like are soldered by reflow.

However, during reflow, there is a risk that molten solder may flow from the electrode region into, for example, a wiring region that is continuous with the electrode region.

On the other hand, in such a wiring board, there is a structure in which the conductor pattern and the resistor pattern are covered with a glass protective film for the purpose of protecting them from external disturbances. According to this structure, the window not covered with the glass protective film is covered with the electrode area. Since the molten solder is provided in the window, the flow of the molten solder is stopped at the border of the window, and there is no fear that the molten solder will flow from the electrode area to other parts of the conductor pattern.

However, the glass protective film as described above is formed by applying glass paste and then baking it.
Since the resistance value of the resistor film decreases due to conductor diffusion during the firing process, there is a problem in that the resistor pattern must be designed with this decrease in mind. Furthermore, if the entire board is resin-molded after mounting the components, the above-mentioned glass protective film is not necessarily necessary in terms of protecting the board.

<Problems to be Solved by the Invention> In view of the problems of the prior art, the main object of the present invention is to prevent molten solder from flowing into the electrode region of the conductor pattern of the wiring board. Another object of the present invention is to provide a method for manufacturing a wiring board in which the design of the wiring board does not become complicated.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, these objects include a process of forming a conductor pattern having an electrode region for soldering components, etc. on the surface of a substrate; A method for manufacturing a wiring board, comprising: forming a resistor pattern according to the formed conductor pattern; applying solder on the electrode area; and attaching the component by reflow. Wiring characterized in that, when forming a body pattern, a solder flow stopper made of a resistor is formed at a boundary between the electrode region and another portion continuous from the electrode region in the conductor pattern. This is achieved by providing a method for manufacturing a substrate.

<Function> In this way, when forming a resistor pattern, by forming a solder stopper made of a resistor at the boundary between the electrode area and other parts of the conductor pattern, molten solder is prevented from flowing into the electrode area. This prevents the liquid from flowing into other parts, and the manufacturing process is simplified.

Embodiments The present invention will now be described in detail with reference to specific embodiments with reference to the accompanying drawings.

FIG. 1 shows a plan view of essential parts of a hybrid IC to which a protection structure according to the present invention is applied.

A conductor pattern 2 and a resistor pattern 3 are formed on the surface of the ceramic substrate 1. The conductor pattern 2 has an electrode region 4 on which a chip component or the like is mounted, and a wiring region 5 continuous to the electrode region 4.

As clearly shown in FIGS. 2 and 3, a solder flow stopper 6 made of a resistor film is formed at the boundary between the electrode region 4 and the wiring region 5. A component 8 is attached onto the electrode region 4 with solder 7.

The manufacturing procedure of the main parts of such a hybrid IC will be explained below. First, the conductor pattern 2 is formed on the surface of the ceramic substrate 1 by, for example, screen printing.

Next, the resistor pattern 3 is formed by screen printing, for example, as described above. At this time, a solder flow prevention part 6 made of a resistor film is simultaneously formed at the boundary between the electrode part region 4 and the wiring part region 5 in the conductor pattern 2.

Next, cream solder 7 is applied onto the electrode area 4 by printing.

Next, the component 8 is mounted on the electrode area 4 covered with the solder 7 and soldered by reflow. At this time, since the solder flow prevention part 6 is formed, the molten solder 7 does not flow from the electrode part area 4 to the wiring part area 5.

In this state, the entire board including the conductor pattern 2, resistor pattern 3, solder 7, components 8, etc. is resin molded.

[Effects of the Invention] As described above, according to the present invention, when forming a resistor pattern, by forming a solder flow prevention part made of a resistor at the boundary between the electrode area and other parts of the conductor pattern, In addition, it is possible to prevent molten solder from flowing from the electrode region to other parts, and the manufacturing process of the wiring board is simplified. Further, it is possible to eliminate the need for applying and baking a glass protective film, and it is possible to prevent a decrease in the resistance value of the resistor film. From the above, the effects of the present invention are significant.

[Brief explanation of the drawing]

FIG. 1 is a plan view of essential parts of a hybrid IC to which the present invention is applied. FIG. 2 is a partially enlarged view of FIG. 1. FIG. 3 is a sectional view taken along the line ■--■ in FIG. 2.

Claims (1)

[Claims] A process of forming a conductor pattern having an electrode area for soldering parts etc. on the surface of the board, a process of forming a resistor pattern according to the formed conductor pattern, and a process of applying solder on the electrode area. A method for manufacturing a wiring board, comprising a step of mounting the component and a step of attaching the component by reflow, the method comprising: forming the resistor pattern; A method of manufacturing a wiring board, comprising forming a solder flow stopper made of a resistor at a boundary between the solder and the solder.