Test method for CAF test module of printed circuit board

Abstract

The invention provides a test method for a CAF test module of a printed circuit board. The module test method comprises the following steps: S1, forming a test hole matrix on the printed circuit test board; s2, bonding pads are connected to the test holes, and the bonding pads are connected in an inclined mode through wires; s3, conducting wires are led out from each group of obliquely-arranged bonding pads at intervals, the conducting wires in the adjacent directions are connected in series, and the two testing wires are connected through an intersection point; s4, connecting the two test lines with test equipment respectively; the test module is not only suitable for a conventional through hole printed board, but also suitable for a high-density HDI board, the CAF-resistant test requirements of different hole wall distances are met by adjusting different hole diameters due to the fact that multiple groups of different hole center distances are covered, the distances are large enough, the selectable space is large for the test condition requirements of 500V and 1000V, and due to the fact that the number of test holes is increased, the test efficiency is greatly improved. And an inclined test combination is more harsh than a standard test, and is more persuasive for the reliability test of the high-performance printed circuit board.

Description

Technical Field

[0001] The invention relates to the technical field of printed circuit board testing, and in particular to a testing method for a CAF testing module of a printed circuit board. Background Art

[0002] CAF (Conductive Anodic Filament), the full name of which is conductive anode filament, refers to the phenomenon that due to the hygroscopic effect, an electric field is formed between the electrodes of a printed circuit board after absorbing water. When metal ions move from one metal electrode to another along the glass fiber yarn, metal is precipitated to form a short circuit.

[0003] With the rapid development of the electronic information industry, in order to meet the needs of intelligence and miniaturization, the line width and line spacing of printed circuit boards tend to be finer, the wiring is more dense, and the aperture is getting smaller and smaller, which makes the insulation spacing continuously shortened, and further deepens the ion migration phenomenon caused by moisture absorption in printed circuit boards. For this reason, CAF testing, as a product reliability testing project, is increasingly favored by major electronic manufacturers, and as a printed circuit board manufacturer, it is necessary to regularly perform CAF testing on the materials used to avoid reliability problems at the end customers;

[0004] The CAF test standard module currently used in the industry has the following design deficiencies:

[0005] Several test holes of the standard module are arranged in parallel, and the test design is relatively loose for reliability testing of high-end printed circuit boards. Summary of the invention

[0006] In view of this, the problem to be solved by the present invention is to provide a testing method for a CAF testing module of a printed circuit board.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A test method for a CAF test module of a printed circuit board; the test module method comprises:

[0009] S1: Open a test hole matrix on a printed circuit test board;

[0010] S2: Connect the pads on the test hole, and connect the pads in an oblique manner through wires;

[0011] S3: Lead out wires from each group of oblique pads, connect the wires in adjacent directions in series, and connect two test lines at the intersection;

[0012] S4: Connect the two test lines to the test equipment respectively.

[0013] The test hole matrix consists of a plurality of transverse test holes and a plurality of longitudinal test holes.

[0014] The test hole matrix includes 13 horizontal test holes and 24 vertical test holes.

[0015] The center distances between the test holes are 1.05mm, 1.25mm, 1.45mm, 1.65mm, 1.85mm or 2.05mm.

[0016] The pads are arranged on the first layer board and the bottom layer board of the printed circuit test board.

[0017] The pads are arranged on the first layer board and the second first layer board adjacent to the first layer board, and on the bottom layer board and the second bottom layer board adjacent to the lower layer board of the printed circuit test board.

[0018] The test module includes: a printed circuit test board with a test hole matrix on the board body, solder pads are constructed on the test holes of the printed circuit test board, the solder pads are connected in an oblique manner through wires, and the oblique solder pad groups are connected in series at intervals through wires, one of the wires is connected to the positive test line, and the other wire is connected to the negative test line.

[0019] The advantages and positive effects of the present invention are:

[0020] (1) This test module is not only applicable to conventional through-hole printed circuit boards, but also to high-density HDI boards;

[0021] (2) This test module covers multiple groups of different hole center distances. By adjusting the different hole diameters, the CAF resistance test requirements of different hole wall spacings can be achieved. The spacing is large enough. For the test conditions of 500V and 1000V, a large space can be selected.

[0022] (3) This test module is more stringent than the standard test by increasing the number of test holes and using an oblique test combination, making it more convincing for reliability testing of high-performance printed circuit boards. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 is a schematic diagram of the test hole matrix;

[0025] Figure 2 It is a schematic diagram of the test hole matrix and a schematic diagram of the mounting pad;

[0026] Figure 3 yes Figure 2 Schematic diagram of connecting the test leads;

[0027] Figure 4 yes Figure 3 Schematic diagram for connecting test equipment; DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0031] like Figures 1 to 4 As shown, the present invention provides a testing method for a CAF testing module of a printed circuit board;

[0032] The test module methods include:

[0033] S1: A test hole matrix is ​​opened on a printed circuit test board. The printed circuit test board is a partial sample of the board to be tested. If the printed circuit test board has anti-CAF performance, the corresponding batch of printed circuit boards all have anti-CAF performance. The test hole matrix consists of a horizontal test hole 1 and a plurality of vertical test holes 1. In this embodiment, the test hole matrix includes 13 horizontal test holes 1 and 24 vertical test holes 1, so that this test module is not only applicable to conventional through-hole printed boards, but also to high-density HDI boards. The test hole 1 can be a through hole or a laser blind hole. The center distance between the test holes 1 is 1.05mm to 2.05mm (each interval is 0.2mm), that is, the center distance between the test holes 1 is 1.05mm or 1.25mm or 1.45mm or 1.65mm or 1.85mm or 2.05mm, respectively. The test holes 1 are opened according to the test material and the corresponding working conditions;

[0034] Since the printed circuit test board covers multiple groups of different hole center distances, the CAF resistance test requirements of different hole wall spacings can be achieved by adjusting the different hole diameters, and the spacing is large enough. For the test conditions of 500V and 1000V, a large space can be selected;

[0035] S2: Connecting pads 2 on the test holes 1, and connecting the pads 2 in an oblique manner through wires. In this embodiment, pads 2 are arranged on the first layer board and the second first layer board adjacent to the first layer board, and the bottom layer board and the second bottom layer board adjacent to the lower layer board of the printed circuit test board, so as to achieve the number of test layers required by the current test;

[0036] S3: Lead out wires at intervals from each group of oblique pads 2, and connect the wires in adjacent directions in series, connect two test lines at the intersection, and then lead out several groups of oblique pads 2 through only two test lines, namely the positive test line 31 and the negative test line 32, by connecting the interval leads in series with the adjacent groups of wires, to achieve testing of the oblique test holes 1 group, which is more demanding than the standard test and more stringent for the reliability test of high-performance printed circuit boards.

[0037] S4: Connect the two test lines to the test equipment respectively; the two test lines are connected to the two test endpoints respectively. The test endpoints are also composed of through holes. The diameter of the through holes depends on the size of the welding parts of the test equipment 4, and generally should be ≥1.0mm. During the test, after connecting the positive and negative poles to the test terminals, the test can be carried out.

[0038] Specifically, the test module includes: a printed circuit test board with a test hole matrix on the board body, a soldering pad 2 is constructed on the test hole 1 of the printed circuit test board, the soldering pads 2 are connected in an oblique manner by wires, and the oblique soldering pads 2 are connected in series at intervals by wires, one of the wires is connected to the positive test line 31, and the other wire is connected to the negative test line 32.

[0039] The working principle and working process of the present invention are as follows:

[0040] S1: Open a test hole matrix on a printed circuit test board;

[0041] S2: Connect pad 2 to test hole 1, and pads 2 are connected in an oblique manner through wires;

[0042] S3: Lead out wires at intervals from each group of oblique pads 2, and connect the wires in adjacent directions in series, and connect two test lines at the intersection;

[0043] S4: Connect the two test lines to the test equipment respectively. If the resistance value displayed by the test equipment is abnormal, the printed circuit test board does not have anti-CAF performance. If the resistance value displayed by the test equipment is normal, the printed circuit test board has anti-CAF performance.

[0044] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of this patent.

Claims

1. A test method for a CAF test module for a printed circuit board, characterized in that ； The test module methods include: S1: Open a test hole matrix on a printed circuit test board; S2: Connect the pads on the test hole, and connect the pads in an oblique manner through wires; S3: Lead out wires from each group of oblique pads, connect the wires in adjacent directions in series, and connect two test lines at the intersection; S4: Connect the two test lines to the test equipment respectively.

2. A test method for a CAF test module for a printed circuit board according to claim 1, characterized in that: The test hole matrix consists of a plurality of transverse test holes and a plurality of longitudinal test holes.

3. A test method for a CAF test module for a printed circuit board according to claim 2, characterized in that: The test hole matrix includes 13 horizontal test holes and 24 vertical test holes.

4. A testing method for a CAF testing module for a printed circuit board according to claim 1, characterized in that: The center distances between the test holes are 1.05mm, 1.25mm, 1.45mm, 1.65mm, 1.85mm or 2.05mm.

5. A testing method for a CAF testing module for a printed circuit board according to claim 1, characterized in that: The pads are arranged on the first layer board and the bottom layer board of the printed circuit test board.

6. A test method for a CAF test module for a printed circuit board according to claim 5, characterized in that: The pads are arranged on the first layer board and the second first layer board adjacent to the first layer board, and on the bottom layer board and the second bottom layer board adjacent to the lower layer board of the printed circuit test board.

7. A testing method for a CAF testing module for a printed circuit board according to claim 1, characterized in that: The test module includes: a printed circuit test board with a test hole matrix on the board body, solder pads are constructed on the test holes of the printed circuit test board, the solder pads are connected in an oblique manner through wires, and the oblique solder pad groups are connected in series at intervals through wires, one of the wires is connected to the positive test line, and the other wire is connected to the negative test line.

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