CN100496183C - Ways to prevent circuit board lines from breaking - Google Patents

Abstract

The invention discloses a method for preventing circuits on a circuit board from breaking. Before the circuit board operation process is performed, a film is attached to the surface of the circuit board to enhance the hardness of the circuit board.

Description

Ways to prevent circuit board lines from breaking

technical field

The invention relates to a method for preventing circuit breakage on a circuit board, in particular to attaching a thin film on the surface of the circuit board to strengthen the hardness of the circuit board.

Background technique

With the rapid development of electronic technology, various electronic products that meet the different needs of consumers are constantly being introduced. Therefore, there are more and more thin, light and small electronic devices, such as cameras, communication devices, notebook computers, liquid crystal displays, and PDAs. Moreover, the design trends of the above-mentioned electronic products mainly focus on light weight, thinner, lower price, higher quality, and higher precision.

Due to the rapid development of various small electronic devices, the volume of the products is getting smaller and smaller, and the electronic components disposed therein are becoming lighter and thinner, such as circuit boards and their circuits, displays, other panels or connectors. The above-mentioned different electronic components often need to be connected and assembled by wires, so cables or flexible circuit boards are usually used for the purpose of transmission and connection when connecting wires.

However, it is worth noting that the above-mentioned flexible circuit boards are light and thin, so when the flexible circuit boards are assembled on the panel, or the parts need to be tested through the flexible circuit boards, the production line personnel often take the flexible circuit boards. During the process of permanent circuit board or when using electric testing tools, because of frequent plugging and unplugging of the circuit board, the line at the front end of the circuit board is disconnected and the appearance of the circuit board is abnormally poor, which eventually increases the failure rate of the circuit board product.

A common flexible circuit board is shown in FIG. 1 , which is a schematic side view of a flexible circuit board 1 . It mainly includes a substrate 10 , a copper layer 101 and a cover layer 103 . The flexible circuit board can be flexed arbitrarily because the substrate 10 is thin, and the substrate 10 is generally composed of yellow-brown polyimide (PI) and colorless polyester resin (PET). And rolling a copper layer 101 on the surface of the substrate 10, the copper layer 101 undergoes a process of photoetching to etch the required part with chemicals such as acid or alkali to form the required circuit pattern. Then, other required electronic components can be successively arranged on the substrate 10 through machining, assembling and other steps to form a so-called flexible circuit board.

Generally, an adhesive 102 needs to be added between the substrate 10 and the copper layer 101 of the flexible circuit board. Moreover, in order to make the thickness of the entire flexible printed circuit meet the requirements, the thickness of the substrate 10 plus the adhesive is usually controlled below 0.1 mm. The common material of the adhesive 102 can be epoxy resin or acrylic material.

In order to prevent the copper layer 101 on the surface of the substrate 10 from being damaged or polluted, the surface of the copper layer 101 will be covered with a cover layer 103. The cover layer 103 is a thin film and has the same material as the substrate 10, which can be used to protect the copper layer 101. line.

Next, please refer to FIG. 2 , which is a schematic diagram of the combination of the flexible circuit board and other connectors. The flexible circuit board 1 can be connected with other circuit boards or connection slots 104 on other circuit boards through the connector 105 at the front end. The terminals in the connection socket 104 are usually electroplated with tin or lead-tin, and the connectors 105 of the flexible circuit board 1 are usually gold fingers plated with 5-15 μm solder. Through the combination of the connector 105 and the connection slot 104, a signal connection can be made between the flexible circuit board and other circuit boards.

As mentioned above, as the size of electronic products becomes thinner, lighter and shorter, the flexible circuit board assembled in the electronic products is also made thinner, so as to connect different electronic components in a limited space. It is worth noting that since the substrate of the flexible circuit board is thin, it is easily deformed by external force, so in the manufacturing process, it will become relatively difficult to transfer automatically, so many testing or assembly actions must be Rely on manual processing.

But the problem that arises is that when the flexible circuit board and the connector are plugged and unplugged manually, the stress generated will mostly be concentrated on the front end of the flexible circuit board, especially because the front end of the circuit board is composed of golden fingers. Compared with the whole flexible circuit board, it will have a thicker structure, so the flexible circuit board is prone to open circuit on the front contact line during the insertion and removal process, resulting in a defect rate of more than 2.17% for the flexible circuit board.

Not only that, but in terms of the appearance of the flexible circuit board inspection, it is often caused by manual contact with the substrate when plugging and unplugging, resulting in scratches and appearance damage on the surface. It also makes the unqualified rate of the detection appearance part as high as 30%. Therefore, in order to avoid the high failure rate of the above-mentioned circuit board, how to solve the situation of open circuit and appearance damage of the flexible circuit board is an urgent issue.

Contents of the invention

The object of the present invention is to provide a method for preventing circuit breakage on a circuit board. Before carrying out the operation process of the circuit board, a thin film is attached to the surface of the circuit board to strengthen the hardness of the circuit board, thereby reducing the circuit board during assembly. The line breaks when unplugged. The above-mentioned operation process is a test process for the circuit board.

The circuit board testing method for preventing circuit breakage of the present invention includes the following steps: (1) attaching a thin film on the surface of the circuit board; then (2) repeatedly inserting and unplugging the circuit board in different slots to perform several test procedures and (3) tearing the film off the circuit board.

In this embodiment, the circuit board has a connector for connecting with the socket in step 2 above, and the attached film is adjacent to the connector. And the thickness of the circuit board is 0.09-0.12mm, wherein the circuit board can be a flexible circuit board. In addition, the thickness of the film is less than 0.15 mm, and the film is a polyester resin (Polyethylene Terephthalate; PET), and is a low-viscosity material.

In order to further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings related to the present invention, but the attached drawings are only for reference and illustration, and are not intended to limit the present invention.

Description of drawings

Fig. 1 is a schematic side view of an existing flexible circuit board;

Fig. 2 is a schematic diagram of the existing flexible circuit board connected to other slots;

Fig. 3 is a schematic side view of the circuit board of the present invention;

Fig. 4 is the test flow schematic diagram of circuit board of the present invention;

Figure 5a is a schematic diagram of a pattern of a circuit board with a thin film of the present invention; and

FIG. 5 b is a schematic diagram of a pattern of a circuit board with a thin film in another embodiment of the present invention.

Explanation of main component symbols

Circuit board 1, 2 Substrate 10, 20

Copper layer 101, 201 Adhesive 102, 202

Overlay 103, 203 Slot 104

Contact 105 Film 207

Connector 206

Detailed ways

The invention provides a method for preventing circuit breakage on a circuit board, especially attaching a thin film on the surface of the circuit board before the operation process of the circuit board to strengthen the hardness of the circuit board, thereby reducing the need for assembly, plugging and unplugging of the circuit board. A line break occurs. A preferred embodiment is listed below to illustrate the present invention, but those skilled in the art know that this is only an example, not intended to limit the invention itself. The content of this preferred embodiment is described in detail as follows.

Please refer to FIG. 3 , which is a schematic side view of the flexible circuit board 2 of the present invention. It mainly includes a substrate 20 , a copper layer 201 , a cover layer 203 and a thin film 207 . The copper layer 201 is attached to the surface of the substrate 20 , and the thin film 207 is also attached to the other surface of the substrate 20 , covering the layer 203 and attached to the other surface of the copper layer 201 .

The substrate 20 is generally made of yellow-brown polyimide (PI) and colorless polyester resin (PET), and a copper layer 201 is rolled on the surface of the substrate 20. The copper layer 201 will be required by the photoetching process. Some of them are etched with chemicals such as acid or alkali to form the required circuit pattern. The substrate 20 of the flexible circuit board 2 and the copper layer 201 generally need to be bonded with an adhesive 202 , and the common material of the adhesive 202 can be epoxy resin or acrylic. Moreover, in order to make the thickness of the entire flexible circuit board meet requirements, the thickness of the circuit board is controlled at 0.09-0.12mm.

In order to prevent the copper layer 201 on the surface of the substrate 20 from being damaged or polluted, the surface of the copper layer 201 will be covered with a cover layer 203. The cover layer 203 is a thin film and has the same material as the substrate 20, which can be used to protect the copper 201 circuit. .

In addition, there is a connector 206 at the front end of the substrate 20 , through which the flexible circuit board 2 can be connected to other circuit boards or connection slots on other circuit boards. Since the terminals in the connection slot are usually electroplated tin or lead-tin, and the connector 206 of the flexible circuit board 2 is usually a gold finger plated with 5-15 μm solder, so the combination of the connector 206 and the connection slot can make the flexible circuit board 2 Signal connection between the circuit board and other circuit boards.

In addition, the film 207 is attached to the surface of the substrate 20 and is adjacent to the joint 206 . In this embodiment, the film 207 is a polyester resin (Polyethylene Terephthalate, PET) material, and the thickness is less than 0.15mm. And in order to be attached to the surface of the substrate 20, the film 207 needs to be a low-viscosity material.

Generally speaking, when plugging and unplugging the flexible circuit board and the connector manually, the stress generated will be concentrated at the front end of the flexible circuit board, especially because the connector at the front end of the circuit board is composed of golden fingers. Because the entire flexible circuit board has a thicker structure, it is easy to cause an open circuit on the front contact line during the plugging and unplugging process of the flexible circuit board, resulting in damage to the flexible circuit board.

Therefore, the present invention addresses the above-mentioned deficiency by adding a low-viscosity film to be attached to the circuit board to increase the overall thickness of the circuit board, thus reducing the difficulty in testing or plugging and unplugging due to the thinner circuit board. Fracture or cosmetic damage. And when the circuit board is shipped, the film is torn off to meet the customer's organizational design requirements and achieve internal quality control.

Next, please refer to FIG. 4 , which is a flow chart of the method for preventing circuit breakage on a circuit board according to the present invention. Its circuit board testing method for preventing circuit breakage comprises the following steps: step (1) attaching a thin film to the surface of the circuit board (S401), step (2) repeatedly plugging and unplugging the circuit board in different slots to Perform several test procedures (S402), and the test procedure further includes testing by several test machines. Finally, the step (3) is performed to tear the film off the circuit board (S403), so as to complete the procedure for preventing circuit breakage on the circuit board.

Next, please refer to FIG. 5 a and FIG. 5 b , which are schematic diagrams of the pattern of the circuit board with the film of the present invention. The film 207 is attached to the surface of the circuit board 2 and is close to the joint, thereby strengthening the hardness of the circuit board 2 and reducing circuit breakage during assembly and plugging of the circuit board 2 . 5a and 5b show different structures of the circuit board 2, but it should be noted that in order to achieve the effect of strengthening the rigidity of the circuit board, the film 207 still needs to be adjacent to the joint.

Compared with the traditional technology, the design that the film provided by the present invention is attached to the circuit board has the following advantages:

(1) Since the circuit board manufacturer has added a low-viscosity film to the circuit board during the manufacturing process, it does not require additional manpower to attach the film on the production line. In addition, increasing the overall thickness of the circuit board through the film can reduce the circuit breakage or poor appearance of the circuit board caused by the poor removal of the connector when the production line personnel take the process or use the electrical measurement tool. Finally, the film is removed when the product is shipped. This can not only meet the client's requirements for the thickness of the circuit board, but also solve the problem of disconnection on the circuit board caused by the assembly process of the production line. The design of the invention can reduce the unqualified rate of broken wires on the circuit board from the existing 2.17% to 0%.

(2) Not only that, in terms of the appearance of the circuit board inspection, it is often caused by manual contact with the substrate when plugging and unplugging, resulting in scratches and appearance damage on the surface. The thin film design of the present invention improves the appearance of the circuit board, and its defective rate can be reduced from the existing 30% to less than 0.06%.

Although the present invention has been disclosed in conjunction with the above preferred embodiments, it is not intended to limit the present invention. Any person familiar with the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore The scope of protection of the present invention should be defined by the claims.

Claims (8)

1, a kind of circuit board detection method that prevents rupture of line comprises the following steps:

Step 1 attaches a film in this circuit board surface;

Step 2 plugs this circuit board repeatedly in different slots, to carry out several test programs; And

Step 3 tears off this film from this circuit board.

2, method of testing as claimed in claim 1, wherein this circuit board has a joint, and in order to being connected with this slot of step 2, and this film that attaches is close to this joint.

3, method of testing as claimed in claim 1, wherein this film is to strengthen the hardness of this circuit board, prevent that thus this circuit board from rupture of line taking place when the assembling plug.

4, method of testing as claimed in claim 1, wherein the thickness of this circuit board is at 0.09～0.12mm.

5, method of testing as claimed in claim 1, wherein the thickness of this film is less than 0.15mm.

6, method of testing as claimed in claim 1, wherein this film of step 1 is a mylar.

7, method of testing as claimed in claim 6, wherein this film is a low viscous material, this film tool one viscosity can temporarily keep this film be attached at this circuit board surface unlikely come off and test after this film is torn off from this circuit board.

8, method of testing as claimed in claim 1, wherein this circuit board can be a flexible circuit board.

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