Welding quality test fixture for integrated busbar

Abstract

The utility model discloses a welding quality test fixture for an integrated busbar. The welding quality test fixture comprises a structure assembly used for fixing the integrated busbar to be tested; the front probe is used for being in contact with a laser welding spot position on the front surface of a nickel sheet branch of the integrated busbar to be detected; the reverse probe is used for being in contact with the bottom surface of a busbar branch of the integrated busbar to be tested; the signal leading-out end of the to-be-tested integrated busbar, the front probe and the back probe are respectively connected to a test machine. The testing machine is used for testing the resistance value between the signal leading-out end and the reverse side probe and the resistance value between the front side probe and the reverse side probe. The test fixture optimizes the selection of the test points of the busbar branch and the nickel sheet branch, and realizes the on-resistance test of the busbar branch and the nickel sheet branch, thereby effectively intercepting the problems of solder skips, insufficient solder, insufficient solder, reverse installation of the nickel sheet, double aluminum bars and the like, avoiding leak detection and preventing defective products from flowing out.

Description

TECHNICAL FIELD

[0001] The utility model relates to the detection technical field of integrated busbar, especially relates to a kind of for new energy CCS, FPC nickel sheet branch and busbar laser welding foolproof leak detection of laser welding test fixture and method. BACKGROUND

[0002] CCS (integrated busbar) is the electrical connection structure in battery module, by integrating information acquisition component (wire harness / FPC / FFC etc.), plastic structural component, busbar (aluminum row) etc. Part into a module, install in battery module, realize the function such as high voltage series-parallel connection of battery cell, temperature sampling of battery, battery cell voltage sampling and overcurrent fuse, belong to part of BMS battery management system.

[0003] In new energy CCS, FPC nickel sheet branch and busbar are laser welded, due to the characteristics of welding process, there will be problems such as incomplete welding, virtual welding, conventional function electric test only sets needle at the head and tail of each network, for testing the conductivity of each network, if nickel sheet and busbar are not welded well or only contact type conduction cannot be detected, it is easy to flow out, leading to customer application product function failure, therefore a new type of test fixture test method is proposed, which can stably detect these problems.

[0004] The existing CCS test fixture measures the conduction resistance by two-wire method. There are a total of 2 groups of probes, one probe in each group, one group of probes is excitation current source; The other group is voltage measurement. Both groups of probes contact the busbar face. Each busbar branch is connected by a nickel sheet branch and an FPC line, and is led out by a PIN needle of the connector of the FPC signal lead-out end. When measuring, the probe forms a loop through the busbar branch, nickel sheet branch, FPC line and PIN needle of the connector. As shown in Figure 1 .

[0005] 1, when incomplete welding problem occurs, nickel sheet and busbar are connected in contact, resistance changes little, two-wire method measures resistance accuracy low, and interception failure may occur. As shown in Figure 2 .

[0006] 2, when nickel sheet is under busbar, nickel sheet and busbar are only connected in contact, and interception failure may occur. As shown in Figure 3 .

[0007] 3, when double busbar problem occurs, excitation current does not pass through lower busbar, and conduction resistance does not change, so the problem cannot be intercepted, and double busbar may lead to poor welding with battery cell, which has high safety risk. As shown in Figure 4 .

[0008] Therefore, a new type of test fixture and method are needed, which can stably detect these problems. Utility model content

[0009] The utility model aims at providing a welding quality test fixture of integrated busbar to detect the welding abnormal problem of the nickel sheet branch and the busbar branch of the new energy integrated busbar.

[0010] A welding quality test fixture of integrated busbar, comprising:

[0011] A structure assembly for fixing the integrated busbar to be tested; and

[0012] A front probe for contacting the front surface of the nickel sheet branch of the integrated busbar to be tested;

[0013] A back probe for contacting the bottom surface of the busbar branch of the integrated busbar to be tested;

[0014] The signal lead-out end of the integrated busbar to be tested, the front probe and the back probe are connected to a test machine respectively; the test machine is used to test the resistance value between the signal lead-out end and the back probe and between the front probe and the back probe.

[0015] Further, the position of the front probe contacting the front surface of the nickel sheet branch is set as the laser welding point of the nickel sheet branch and the busbar.

[0016] Further, the front probe and the back probe each comprise an excitation current source probe and a voltage measurement probe.

[0017] Further, the front probe and the back probe each comprise at least one group of excitation current source probe and voltage measurement probe.

[0018] Further, the structure assembly comprises a base, a lower mold plate, an upper platform and a pressing mechanism.

[0019] The lower mold plate is fixed on the base and used to fix the integrated busbar to be tested.

[0020] The back probe is installed on the base, protrudes from the lower mold plate and contacts the bottom surface of the busbar branch of the integrated busbar to be tested.

[0021] The pressing mechanism is fixed on the base and drivingly connected with the upper platform to push down the upper platform.

[0022] The front probe is installed on the upper platform and contacts the integrated busbar to be tested by the pressing of the upper platform.

[0023] Further, the lower mold plate is provided with a positioning groove consistent with the thickness of the busbar.

[0024] Further, the height of the reverse probe above the positioning groove is 1-1.5mm.

[0025] The utility model discloses a significant feature compared with prior art is:

[0026] The test fixture optimizes the selection of test points of the busbar branch and the nickel sheet branch, realizes the on-resistance test of the busbar branch and the nickel sheet branch, thereby effectively intercepting problems such as missing welding, less welding, virtual welding, nickel sheet reverse installation and double aluminum row, and avoiding missing detection and preventing defective products from flowing out. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is the schematic diagram of the on-resistance detection of the existing integrated busbar;

[0028] Figure 2 is the cause schematic of the missing detection of CCS laser welding Figure 1 ;

[0029] Figure 3 is the fault schematic of the new energy CCS laser welding Figure 2 ;

[0030] Figure 4 is the fault schematic of the new energy CCS laser welding Figure 1 ;

[0031] Figure 5 is the welding quality test schematic diagram of the integrated busbar of the utility model;

[0032] Figure 6 is the structure schematic diagram of the welding quality test fixture of the integrated busbar of the utility model;

[0033] Figure 7 is the schematic diagram of the front probe and the nickel sheet branch front contact;

[0034] Figure 8 is the schematic diagram of the reverse probe and the busbar branch contact.

[0035] Wherein: 1-CCS;101-busbar branch;102-nickel sheet branch;103-laser welding point;104-FPC circuit board;105-connector;2-test fixture;201, 202-front probe;203, 204-reverse probe;205-base;206-lower template;207-upper platform;208-pressing mechanism. DETAILED DESCRIPTION

[0036] To further illustrate the embodiments, the utility model provides has the drawing. These drawings are part of the utility model disclosure, it is mainly used to illustrate the embodiment, and can cooperate with the related description of the specification to explain the operation principle of the embodiment. With reference to these contents, those skilled in the art should understand other possible implementation ways and the advantages of the utility model. The components in the drawing are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0037] The utility model is further illustrated in conjunction with the drawings and specific embodiments.

[0038] As Figure 5 The utility model gives a connection diagram of the welding quality test system of integrated busbar. In the embodiment, the integrated busbar 1 includes a plurality of busbar branches 101, a plurality of nickel sheet branches 102 for connecting the busbar branches 101, an FPC circuit board 104, and a connector 105 as the signal lead-out end of the FPC circuit board 105. Each busbar branch 101 is led out from the connector 105 through a nickel sheet branch 102 and a circuit in the FPC circuit board 104. The form of the connector 105 is not limited, which can be a plug, a socket or a gold finger, etc.

[0039] The welding quality test system of integrated busbar is composed of the integrated busbar 1 to be tested, the front surface probe 201, 202 in contact with the front surface of the laser welding point 103 of the nickel sheet branch 102 of the integrated busbar 1 to be tested, the back surface probe 203, 204 in contact with the bottom surface of the busbar branch 101 of the integrated busbar 1 to be tested, and a test machine (not shown), etc. The front surface probe 201, 202, the back surface probe 203, 204 and the connector 105 are connected with the test machine through lead wires respectively.

[0040] In the embodiment, the welding quality test system of integrated busbar is composed of the integrated busbar 1 to be tested, a test fixture 2 and a test machine (not shown), etc. The following design is adopted:

[0041] Four-wire method measurement is adopted for on-resistance test; at least two test needles are arranged for each group of test probes, which are excitation current source probe and voltage measurement probe respectively, for accurate measurement of on-resistance. For example, the front surface probe 201, 202 are excitation current source probe and voltage measurement probe respectively; the back surface probe 203, 204 are excitation current source probe and voltage measurement probe respectively.

[0042] The connector 105 of the signal lead-out end of the FPC circuit board 104 is taken as the test point A; the test points of the bus bars are changed to the reverse side of the nickel sheet welding area, and a set of test probes-reverse side probes 203, 204 are arranged as the test point C; a set of test probes-front side probes 201, 202 are additionally arranged at the nickel sheet welding area of the nickel sheet branch 102 as the test point B, which is used for testing the conduction resistance value of the nickel sheet branch 102 to the bus bar branch 101.

[0043] 3. Due to the insufficient flatness of the welding surface, in order to avoid the false connection of the probe, 1-2 sets of probes can be added on the same network to ensure the stability of the test.

[0044] The front and reverse side probes and the integrated bus bar 1 to be tested are contacted by the test fixture 2, and the conduction test is performed by the testing machine. During the conduction test, the test is performed in two groups:

[0045] 1. The test point A-test point C is used for testing the conduction resistance value of the whole network, and according to the size of the network line resistance, it can be set to be not more than 300-2000 milliohms.

[0046] 2. The test point B-test point C is used for testing the conduction resistance value of the welding front and reverse sides, and when the nickel sheet branch 101 and the bus bar branch 102 are normally welded, the conduction resistance value is less than 100 micro-ohms.

[0047] As shown in Figure 3 The utility model discloses a kind of integrated bus bar welding quality test fixtures (hereinafter referred to as test fixture).Test fixture 2 is composed of base 205, lower template 206, reverse side probe 203, 204, upper platform 207, front side probe 201, 202 and lower pressing mechanism 208 etc..Lower template 206 is milled into positioning groove according to the position and thickness of the bus bar 102 of integrated bus bar 1 to be tested, and the positioning hole (diameter 1.5-2.5mm) of reverse side probe 203, 204.Lower template 206 is fixed on base 205 for positioning integrated bus bar 1 to be tested.Reverse side probe 203, 204 are fixed in base 205, and needle head is 1-1.5mm higher than positioning groove.Front side probe 201, 202 are installed on upper platform 207, and the position corresponds to reverse side probe 203, 204.In specific application, test probe is telescopic design.Front side probe 201, 202, reverse side probe 203, 204 are electrically connected with testing machine through lead wire.Lower pressing mechanism 208 is installed on base 205 and is drivingly connected with upper platform 207, and lower pressing mechanism 208 is used to press down upper platform 207, so that front and reverse side probes and integrated bus bar 1 to be tested can be reliably contacted, and hardware preparation of completion test is completed.

[0048] In the embodiment, base 205, lower template 206, upper platform 207 and other structural components can be processed and assembled by insulating materials such as bakelite and acrylic.

[0049] Specific detection steps:

[0050] 1. Put the integrated busbar 1 into the positioning groove of the lower mold plate 206 of the test fixture.

[0051] 2. Use the pressing mechanism 208 to press the upper platform 207, so that the front probes 201, 202 contact the front surface of the nickel sheet branch 102, and the back probes 203, 204 contact the back surface of the busbar branch 101.

[0052] 3. Perform the conduction test.

[0053] In this embodiment, whether there are problems such as double busbars, nickel sheets under busbars, and missing welds is mainly determined by the contact resistance of test point B to test point C. When there is no welding or multiple aluminum bars, the contact resistance of test point B to test point C will exceed 10 milliohms, which is much larger than the conduction resistance of normal welding. According to the interval of the measured conduction resistance of normal welding, the determination threshold of the conduction resistance can be set. The interval of the measured conduction resistance of normal welding is 30-60 microohms, so the determination threshold can be set to 2-3 times the average conduction resistance in the test machine, such as 80 microohms. When the nickel sheet branch 101 and the busbar branch 102 are normally welded, the conduction resistance is less than 80 microohms, and the test passes. When there are problems such as double busbars, nickel sheets under busbars, and missing welds, the conduction resistance will be greater than 80 microohms, and the test will fail.

[0054] Using this method, problems such as missing welds, missing welds, false welds, nickel sheet installation in reverse, double aluminum bars, etc. can be effectively intercepted, and missed detection and defective products can be prevented from flowing out.

[0055] Although the utility model is specifically shown and introduced in combination with the preferred embodiments, those skilled in the art should understand that various changes can be made to the utility model in form and details without departing from the spirit and scope of the utility model defined by the appended claims, and all changes are within the protection scope of the utility model.

Claims

1. A welding quality testing fixture for integrated busbars, characterized in that: include: Structural components used to fix the integrated busbar under test; and A front probe for making front contact with the nickel sheet branch of the integrated busbar under test; A reverse probe used to contact the bottom surface of a busbar branch of the integrated busbar under test; The signal output terminal of the integrated busbar under test, the front probe, and the back probe are respectively connected to the test machine; the test machine is used to test the resistance between the signal output terminal and the back probe, and between the front probe and the back probe.

2. The welding quality testing fixture for the integrated busbar as described in claim 1, characterized in that: The position where the front probe and the front contact of the nickel sheet branch are set as the laser solder joint where the nickel sheet branch is welded to the busbar.

3. The welding quality testing fixture for the integrated busbar as described in claim 1, characterized in that: Both the front and back probes include an excitation current source probe and a voltage measurement probe.

4. The welding quality testing fixture for the integrated busbar as described in claim 3, characterized in that: Both the front and back probes include at least one set of excitation current source probes and voltage measurement probes.

5. The welding quality testing fixture for the integrated busbar as described in claim 1, characterized in that: The structural components include: a base, a lower template, an upper platform, and a pressing mechanism; The lower template is fixed on the base and used to fix the integrated busbar to be tested; The reverse probe is mounted on the base, protrudes from the lower template, and contacts the bottom surface of the busbar branch of the integrated busbar to be tested; The pressing mechanism is fixed on the base and connected to the upper platform drive to push the upper platform down; The front probe is mounted on the upper platform and makes contact with the integrated busbar under test by pressing down on the upper platform.

6. The welding quality testing fixture for the integrated busbar as described in claim 5, characterized in that: The lower template is provided with a positioning groove that matches the thickness of the busbar.

7. The welding quality testing fixture for the integrated busbar as described in claim 6, characterized in that: The height of the reverse probe above the positioning groove is 1 to 1.5 mm.

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