JPH0529753A - Manufacture of printed wiring board - Google Patents

Abstract

PURPOSE:To provide a manufacturing method of a printed board which enables a masking agent (solder resist) to be separated easily, making the best use of the properties of a thermosetting masking agent. CONSTITUTION:This invention relates to a manufacturing method of a printed board 11 where an allowance 13 is continuously formed by way of a board dividing cut groove 14. When a thermosetting masking agent 16 is applied to a portion for which no soldering is required in a soldering process which masks by means of the thermosetting masking agent 16, the board dividing cut groove 14 and even a part of the allowance 13 are continuously coated with the thermosetting masking agent 16 so that it may be used as a tongue 17. After soldering, the board dividing cut groove 14 is cut off and the thermosetting masking agent 16 is separated by means of the tongue 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a printed circuit board, and more particularly to a method of manufacturing a printed circuit board in which a masking agent (so-called solder resist) can be easily peeled off in a soldering process or a plating process of manufacturing a printed circuit board. Regarding

[0002]

2. Description of the Related Art Conventionally, a printed circuit board is generally called a so-called etching method in which a copper clad laminate is used, and unnecessary portions of the copper foil are dissolved and removed with a chemical to leave only a necessary conductor pattern. The manufacturing method used is often used. After forming a predetermined conductor pattern on the printed circuit board in this way, mount chip parts, insert parts, etc.,
The printed circuit board and chip parts / inserted parts are soldered by a flow soldering device. At this time, in the printed circuit board, such as a gold-plated connector portion to be plugged in, a contact / terminal, etc., or a soldered portion of a component that must be retrofitted after mounting due to the characteristics of the component,
When there is an unneeded portion for soldering, a masking technique such as using a masking jig or applying a masking tape or a masking agent is generally adopted.

However, the masking jig is expensive and has a problem that it is specialized due to the size of the connector of the printed circuit board and lacks versatility. Further, when a masking tape is used, the adhesive of the masking tape is used as a connector. There is a problem that it remains on the surface or the like to cause contact failure, or deteriorates the solderability of the post-installed component. For this reason, a coating technique of a masking agent (so-called solder resist) called a strippable resist ink is widely used because it has a relatively good protective effect on the mask surface and is easy to remove after soldering.

The material of the masking agent is a thermosetting polymer, and the method of use is to screen-print a solution-like masking agent and cure at 120 to 150 ° C. for about 5 to 10 minutes. Then, after mounting various components and fixing them in a flow soldering process, the masking agent (solder resist) is peeled off.

The above masking agent (solder resist) is
When used only by heat curing, it has elasticity and can be easily peeled off by scratching the edge of the massaging agent with the tip of the toe easily. It is widely used because of its relatively good protection and good peelability when the heat load is low.

[0006]

However, as the heat load increases such that a heat amount larger than that of the flow type soldering is applied, the masking agent becomes hard and difficult to peel, and the masking agent becomes peelable due to excessive heat load. Occurs.
In particular, when the amount of heat applied during the flow-type soldering is larger than the amount of heat applied, peeling may occur unless a sharp jig is used, which may deteriorate workability and cause scratches on the mask surface. Therefore, the present inventors have made an invention focusing on the peeling of the masking agent and facilitating the peeling of the masking agent (solder resist) for manufacturing a printed circuit board.

An object of the present invention is to make use of the characteristics of a thermosetting masking agent in the process of manufacturing a printed circuit board,
It is an object of the present invention to provide a method for manufacturing a printed circuit board in which the masking agent (so-called solder resist) can be easily peeled off.

[0008]

A method of manufacturing a printed circuit board according to the present invention is a method of manufacturing a printed circuit board in which a discarding margin is continuously formed through a board dividing cut groove, in which the printed circuit board is soldered. In this step, a soldering step is performed by masking a portion that does not need to be soldered with a thermosetting masking agent, and the soldering step includes applying a thermosetting masking agent to a portion of the printed circuit board where soldering is unnecessary. When applying, a step of continuously applying a thermosetting masking agent up to a part of the board dividing cut groove and a part of the discarding margin to form a tongue portion, and separating the board dividing cut groove after soldering And a step of peeling the thermosetting masking agent from the tongue.

According to the second aspect of the present invention, a step of applying a thermosetting masking agent to form a tongue portion, and cutting the substrate dividing cut groove after plating to separate the thermosetting masking portion from the tongue portion. The step of peeling the agent can be applied to the plating step instead of the soldering step.

[0010]

In the manufacturing method of the present invention, when the thermosetting masking agent is applied to a portion of the printed circuit board where soldering is unnecessary, the cut groove for dividing the substrate and a part of the discarding margin are continuously formed. Since the thermosetting masking agent is applied to form the tongue, the tongue is applied continuously from a part of the discarding margin to the board dividing cut groove and the part where soldering is unnecessary. When the discard allowance portion is later separated from the substrate dividing cut groove, the tongue portion at the discard allowance portion remains. Then, the thermosetting masking agent is separated from the remaining tongue. In this way, the tongue remains by separating the throwing allowance, so not only can the masking agent be peeled off much easier than before, but it can also be easily peeled off even if the masking agent is firmly attached to the substrate due to overheating. Is. Further, as in the second aspect, instead of the soldering step, the same can be applied to the plating step.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The members, arrangements, and the like described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention. 1 and 2 show an embodiment of a method for manufacturing a printed circuit board according to the present invention, and in this example, an example in which eight chamfers are used as the printed circuit board 10 for multi-chamfering is shown.

The printed circuit board 10 for multiple cutting shown in this example.
Is a resist coating step 20, an etching step 30,
It comprises a resist stripping process 40 and a mounting and flow soldering process 50. The resist coating step 20, the etching step 30, and the resist stripping step 40 are the same as the conventionally known techniques. To briefly describe these, the resist coating step 20 is applied to a substrate such as a copper clad laminate or a printed wiring board. Depending on the production equipment, the standard length material is divided into integers and used, and only the necessary parts as the conductive pattern are coated on the surface with the acid resistant material (etching resist). That is, acid-resistant ink is screen-printed, or a photosensitive agent is applied to the entire surface, and then only the conductive pattern portion is exposed, and then development and fixing are performed to leave an acid-resistant film to form a positive pattern. In the etching step 30, a chemical (etching solution) that dissolves copper is sprayed on the copper foil surface to dissolve and remove the copper foil other than the conductive pattern. In this way, the copper foil in the area covered with the etching resist remains undissolved. In the resist stripping step 40, the etching resist is stripped and removed using a chemical to expose the conductor pattern.

Next, as shown in FIG. 2, in the printed circuit board 10 for multi-chambering formed as described above, each printed circuit board 11 is surrounded by the punching groove 12 and the discard allowance 13, and is discarded. A board dividing cut groove 14 is formed between the margin 13 and each printed circuit board 11. Therefore, each printed circuit board 11 is configured to be separated and independent by removing the discarding margin 13. A conductor pattern portion 15 is formed on the printed circuit board 11 of this example, and the conductor pattern portion 15 is a portion where soldering is unnecessary.

Then, a mounting and flow soldering step 50 for mounting and fixing components (chip components, insertion components) on the above-described printed circuit board 10 for multi-chambering is performed. The mounting and flow soldering step 50 of this example includes a masking step 51, a component mounting 52, and a series of flow soldering steps 53 of flux application, heating, soldering, cooling, and cleaning.
And a masking peeling step 54.

The masking step 51 does not require soldering, such as a gold-plated connector portion to be plugged in, a contact / terminal, etc., or a soldering portion of a component which must be retrofitted after mounting depending on the characteristics of the component. This is done in order to cover the part and not to touch the molten solder.
The masking agent 16 is screen-printed on the printed circuit board 10 for multiple printing. In this example, as described above, the soldering unnecessary portion is the conductor pattern portion 15, and the thermosetting masking agent 16 is continuously applied to a part of the board dividing cut groove 14 and the discarding margin 13. Then tongue 17
To form as.

In this example, a vinyl chloride type thermosetting polymer is used as the masking agent 16, and the masking film thickness is 15
The coating was dried at about 0 μm and curing conditions of 150 ° C. for 10 minutes. Further, as the shape of the masking agent 16 in this example, a tongue portion 17 is formed in addition to a portion that completely covers the conductor pattern portion 15. The tongue portion 17 crosses over the substrate dividing cut groove 14, It is applied in a roughly trapezoidal shape of about 2 mm on the discarding margin 13 side.

Next, a component is attached to a predetermined position on the printed circuit board 11 (component mounting), and a series of flow soldering steps 53 of flux application, heating, soldering, cooling and cleaning are performed. A series of flow soldering steps 53 of this flux application, heating, soldering, cooling, and cleaning are
Since this is the same as the conventionally known technique, its description is omitted.

After each of the above steps, a masking peeling step 54 is performed. This masking peeling step 54
Is to fold the printed circuit board 10 for multiple cutting along the cut groove 14 for dividing the board and cut the portion of the discarding margin 13. In this way, the masking agent 16 is not cut at the substrate-dividing cut groove 14, but the tongue portion 17 is peeled off from the discarding margin 13. Next, the remaining tongue 1
If the masking agent 16 is peeled off while holding the portion No. 7, it is possible to relatively easily peel off even the masking agent 16 that has been fixed due to overheating.

As described above, in the above-mentioned embodiment, in the case of the prior art in which the soldering is not necessary on the substrate, it takes a long time to remove the first peeled portion with the nail, so that it is completely completed. It took 2 minutes to peel it off, but by adding the tongue portion 17 as in this example, it was possible to complete the process in a few seconds.

FIG. 3 shows a printed circuit board according to another embodiment. The same components are designated by the same reference numerals and the description thereof will be omitted. In this example, the printed circuit board 10 for multiple cutting
The present invention can be suitably applied regardless of the difference in the portion where the discarding margin 13 is formed.

In each of the above-described embodiments, the example applied to the soldering step is shown. However, in addition to the soldering step, the step of applying the thermosetting masking agent 16 to form the tongue portion 17 and the predetermined step after the step. By separating the substrate dividing cut groove 14,
The step of peeling the thermosetting masking agent 16 from the tongue portion 17 can be applied to the plating step instead of the soldering step.

[0022]

As described above, according to the manufacturing method of the present invention, when the thermosetting masking agent is applied to a portion where soldering or plating is unnecessary, the cut groove for dividing the substrate and the discarding margin portion are removed. The thermosetting masking agent is continuously applied to the tongue to form the tongue. Therefore, when the throw-away margin is cut off from the board dividing cut groove, the tongue at the throw-away margin remains, and the remaining tongue remains. It is possible to easily separate the thermosetting masking agent from the part. This not only makes it easier to remove the masking agent than before, but also
Even a masking agent strongly adhered to a substrate due to overheating can be easily peeled off, which is extremely effective in improving productivity.

[Brief description of drawings]

FIG. 1 is a flowchart showing a manufacturing process of a printed circuit board.

FIG. 2 is a plan view showing a printed circuit board according to an embodiment of the present invention.

FIG. 3 is a plan view showing a printed circuit board of another embodiment according to the present invention.

[Explanation of symbols]

10 Printed circuit board for multiple cutting 11 printed circuit boards 12 punched groove 13 Discarding charges 14 Board dividing cut groove 15 Parts where soldering is unnecessary (conductor pattern part) 16 Thermosetting masking agent 17 tongue 20 Resist coating process 30 etching process 40 Resist stripping process 50 Mounting and flow soldering process 51 Masking process 52 Parts mounting 53 Series of flow soldering process 54 Peeling process

Claims (2)

[Claims] Plating masking process 1. In a method of manufacturing a printed circuit board in which a discarding margin is continuously formed through a board dividing cut groove, a thermosetting masking is applied to a portion where soldering is unnecessary when the printed circuit board is soldered. A soldering step performed by masking with a soldering agent, the soldering step including the cutting groove for dividing the board and the discarding margin when the thermosetting masking agent is applied to a portion of the printed board where soldering is unnecessary. A step of continuously applying a thermosetting masking agent to a part of the portion to form a tongue portion, and cutting the board dividing cut groove after soldering, and peeling the thermosetting masking agent from the tongue portion. A method of manufacturing a printed circuit board, comprising: 2. A method of manufacturing a printed circuit board, wherein a discarding allowance is continuously formed through a substrate dividing cut groove, wherein a portion where plating is unnecessary when a printed circuit board is plated with a thermosetting masking agent. A plating step performed by masking, wherein the plating step is performed on a part of the cut groove for dividing the substrate and a part for discarding when the thermosetting masking agent is applied to a portion of the printed circuit board where plating is unnecessary. To a tongue by continuously applying a thermosetting masking agent, and a step of separating the substrate dividing cut groove after plating and peeling the thermosetting masking agent from the tongue. Printed circuit board manufacturing method.