CN114284160A - IGBT module power terminal welding positioning assembly and method - Google Patents

Abstract

The invention discloses a welding positioning assembly and a welding positioning method for power terminals of an IGBT module in the technical field of IGBT preparation, and the welding positioning assembly comprises a terminal position limiting part, wherein the terminal position limiting part is fixedly arranged on a DBC limiting plate, a plurality of hollowed grooves for inserting and positioning power terminal groups with soldering lugs are formed in the limiting surface of the terminal position, terminal spacing limiting parts for enabling the power terminal groups with the soldering lugs to be perpendicular to the terminal position limiting part are arranged between the power terminal groups with the soldering lugs, the DBC limiting plate is arranged on a substrate, and DBC soldering lugs are arranged in the DBC limiting plate. The invention can ensure the reliability of products and improve the welding consistency of module terminals.

Description

IGBT module power terminal welding positioning assembly and method

Technical Field

The invention relates to a welding positioning assembly and method for a power terminal of an IGBT (insulated gate bipolar transistor) module, belonging to the technical field of IGBT preparation.

Background

Insulated Gate Bipolar Transistors (IGBTs) are the most advanced power semiconductor devices in third-generation power electronic devices, have the advantages of high frequency, high voltage, large current and the like, are core devices in the fields of flexible alternating current/direct current transmission, new energy power generation, electric energy quality control and the like, and are currently widely applied in related industries. In an IGBT module package, soldering of a chip to a Copper-clad ceramic backing (DBC) is generally referred to as primary soldering; the welding of the liner plate subunit consisting of the chip and the DBC liner plate and the copper or composite material substrate is called secondary welding, and the primary welding and the secondary welding are key processes influencing the module packaging quality.

At present, soldering paste is usually used for soldering when a high-power IGBT module terminal is soldered, a large amount of soldering flux exists no matter the terminal is soldered by a manual electric soldering iron or soldered after the soldering paste is coated on the bottom of the terminal, and the reliability of the module is reduced due to the residual soldering flux after soldering and cleaning. For a high-reliability high-power IGBT module, a large amount of soldering flux is left on the surface of an element and the inner wall of welding equipment after welding is finished, the soldering flux on the element is difficult to be completely cleaned by cleaning equipment, and the long-term reliability of a product is directly influenced by the residual soldering flux. The flaky formed solder (soldering lug) does not have soldering flux, and after soldering, the soldering lug does not need to be cleaned, so that the cleaning procedures can be reduced, the soldering cavity is not polluted after soldering, the soldered product does not have soldering flux residue, and the reliability of the product is not influenced. In addition, the soldering amount of the bottom of each module terminal is different due to the adoption of electric soldering iron for soldering or the coating of soldering paste, and the consistency of soldering of the module terminals is difficult to ensure. And adopt soldering lug parcel terminal bottom to weld again, can ensure the stability and the uniformity of terminal bottom soldering tin volume.

However, when the terminal is welded by the soldering lug, the terminal, the soldering lug material, the DBC and the substrate are not adhered, so that the relative positions are easy to change in the assembling process, the soldering failure is caused, and the soldering quality and the soldering consistency cannot be guaranteed.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a welding positioning assembly and a welding positioning method for an IGBT module power terminal, which can achieve the effects of ensuring the reliability of products and improving the welding consistency of module terminals.

In order to achieve the purpose, the invention is realized by adopting the following technical scheme:

in a first aspect, the invention provides an IGBT module power terminal welding positioning assembly, which includes a terminal position limiting device, wherein the terminal position limiting device is fixedly placed on a DBC limiting plate, a plurality of hollowed grooves for inserting and positioning power terminal groups with soldering lugs are formed in the surface of the terminal position limiting device, a terminal spacing device is arranged between the power terminal groups with soldering lugs to enable the power terminal groups with soldering lugs to be perpendicular to the terminal position limiting device, the DBC limiting plate is placed on a substrate, and DBC soldering lugs are placed in the DBC limiting plate.

Further, dig the equal symmetry in dead slot both sides and seted up two terminal grooves, and terminal interval spacing two sides edge all is provided with vertical bar arch, the bellied thickness of vertical bar and the degree of depth phase-match in terminal groove.

Furthermore, a plurality of positioning holes are formed in the surface of the DBC limiting plate, and the terminal position is limited and fixed in the positioning holes through positioning pins.

Furthermore, round holes are formed in the top of the terminal spacing.

Further, the size of the terminal spacing limit and the terminal position limit can be customized according to the spacing requirement of the power terminals.

Furthermore, the number of the hollowed grooves is three, and the three hollowed grooves are symmetrically arranged on the limiting surface of the terminal position at equal intervals.

Furthermore, the power terminal group with the soldering lug comprises two power terminals with the soldering lugs, the power terminal group with the soldering lugs comprises a power terminal, the bottom of the power terminal is wrapped by the bottom of the terminal soldering lug for one circle, and the width of the terminal soldering lug is smaller than the width of the power terminal by 0.5 mm.

In a second aspect, the invention provides a welding and positioning method for an IGBT module power terminal, comprising the following steps:

placing the DBC limiting plate on the substrate;

sequentially placing a DBC soldering lug and a DBC into the DBC limiting plate based on the placement position of the DBC limiting plate;

the terminal position limit is fixed on a corresponding locating hole on the DBC limiting plate through a locating pin;

placing the power terminal group with the soldering lug into the hollowed groove for limiting the position of the terminal according to the position limiting and placing direction of the terminal;

and spacing and placing the terminal space between the two power terminals with soldering lugs in each hollowed groove.

Compared with the prior art, the invention has the following beneficial effects:

the soldering terminal and the substrate can be fixed on the soldering area of the substrate, and the terminal is fixed on the corresponding position on the DBC. The terminal position limit and the terminal space limit of different sizes can be designed according to the difference of the terminal size, the welding position and the gaps among the terminals. The DBC limiting plate tool with different sizes can be designed according to substrates and DBCs with different sizes, welding of products with different sizes is achieved, the welding sheet prefabrication and terminal welding device is suitable for mass product production, a standardized process flow is provided, the uniformity of welding layers of the DBCs and the substrates and the uniformity of welding layers of the terminals and the DBCs are good, the reliability of products is improved, pollution of scaling powder to equipment is avoided, the service life of welding equipment is prolonged, and the stability of welding of products is improved; only need adopt unified parcel to have the terminal of prefabricated soldering lug during the operation, rethread terminal welding set fixes during the welding terminal, guarantees the welded uniformity of terminal, has reduced scrapping that artificial factor leads to, and stability is higher, has improved the quality and the reliability of module.

Drawings

Fig. 1 is a schematic view of a terminal with a bottom-wrapped solder tab according to an embodiment of the present invention;

fig. 2 is a schematic diagram of terminal position limiting provided in the embodiment of the present invention;

fig. 3 is a schematic diagram illustrating spacing between terminals according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a substrate with a DBC pad, a DBC, and a DBC limiting plate disposed thereon according to an embodiment of the present invention;

fig. 5 is a schematic diagram of the position of the terminal on the basis of fig. 4 after the position limiting according to the embodiment of the present invention is placed;

fig. 6 is a schematic diagram of a power terminal and a terminal spacing position after the power terminal and the terminal spacing position are placed on the basis of fig. 5 according to an embodiment of the present invention;

fig. 7 is an exploded view of an integral assembly according to an embodiment of the present invention.

In the figure: 1. a power terminal; 2. a terminal pad; 3. spacing the terminal distance; 4. a power terminal with a soldering lug; 5. limiting the position of the terminal; 6. a DBC limiting plate; 7. DBC; 8. a DBC bonding pad; 9. a substrate.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

Example (b):

a welding and positioning assembly for a power terminal of an IGBT module is shown in figure 1, a power terminal 1 with a terminal soldering lug 2 wrapped at the bottom is combined into a power terminal 4 with a soldering lug, the power terminal 4 can be prepared in advance as a raw material of a welding process, the width of the terminal soldering lug 2 can be adjusted according to the width of the bottom of the power terminal 1, the width of the terminal soldering lug 2 is slightly smaller than the width of the power terminal 1 and is generally smaller than the width of the power terminal 1 by about 0.5mm, and the length is preferably one circle of the bottom of the wrapped terminal.

As shown in fig. 2, the terminal spacing 3 is used for ensuring the gap between the two power terminals 1 and the perpendicularity of the power terminals 1 after welding is completed, the minimum gap between the two power terminals 1 can be ensured through the thickness of the device, and the inconsistency of the power terminals 1 after welding is completed, which is caused by manual assembly, is reduced. In addition, a round hole is formed above the device, so that the device is convenient to disassemble and take, and the assembly efficiency is improved.

As shown in fig. 3, the terminal position limiter 5 is used for fixing the position of the power terminal 1; the device is fixed in a positioning hole reserved on a DBC limiting plate 6 through a positioning pin, three hollowed grooves on the surface are used for determining the relative position of a power terminal 1, the relative fixation of the position of the power terminal 1 on the DBC after welding is finished every time is ensured, two terminal grooves are symmetrically arranged on two sides of each hollowed groove on a terminal position limiting 5, and the edges of two sides of the spacing limit 3 of the terminal are provided with vertical strip-shaped bulges, the thickness of the vertical strip-shaped bulges is matched with the depth of the terminal groove, when the terminal spacing limit 3 is inserted into the hollowed groove on the terminal position limit 5, the two power terminals 1 are respectively positioned at two sides of the terminal spacing limit 3 and are simultaneously positioned in two asymmetric terminal grooves at two sides of the hollowed groove, two other terminal grooves which are not provided with the power terminals 1 are abutted to the vertical strip-shaped protrusions, so that the overall stability between the terminal position limit 5 and the terminal interval limit 3 is ensured.

The specific implementation method is as follows, as shown in fig. 4, firstly, the DBC limiting plate 6 is placed on the substrate 9, and the DBC pads 8 and DBC 7 are placed according to the position of the DBC limiting plate 6. As shown in fig. 5, the terminal position limiter 5 is then fixed to the corresponding positioning hole on the DBC limiting plate 6 by its positioning pin, so that it can be ensured that the position of the power terminal on the DBC is relatively fixed after the welding is completed. As shown in fig. 6, the power terminal 4 with soldering lug is placed in the hollow groove of the terminal position limit 5 according to the placing direction of the terminal position limit 5, and finally the terminal space limit 3 is placed between the two power terminals 1, so as to ensure the positioning and fixing in the assembling and welding process. As shown in fig. 7, after the assembly according to the above steps, the whole is placed in a vacuum welding furnace for welding, and after the IGBT module and the welding apparatus are cooled, the terminal pitch limit 3, the terminal position limit 5, and the DBC limit plate 6 are sequentially taken out. In addition, the terminal spacing 3 and the terminal position spacing 5 can flexibly modify the size according to the design requirement of the spacing between the two power terminals 1 of the module, and the problem that the method is not suitable due to the change of the module design is avoided.

The method for improving the welding consistency of the terminals of the high-power IGBT module not only ensures the consistency of the soldering tin quantity at the bottom of the power terminal, but also ensures the consistency of the welding position of the power terminal in the module, reduces the rejection rate of module welding, and improves the product quality and reliability. The method can be used for manual placement operation and machine identification placement operation, can be matched with an automatic production line, reduces interference of human factors, and improves consistency and reliability of modules.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims (8)

1. The utility model provides a IGBT module power terminal welding position subassembly, characterized by, it is spacing including the terminal position, the terminal position is spacing fixed to be placed on a DBC limiting plate, and the terminal position is spacing to be offered a plurality of power terminal groups that supply to take the soldering lug and to insert the groove of digging out of establishing the location on the surface, it is spacing to be equipped with between the power terminal group of taking the soldering lug to make the two spacing vertically terminal interval that keeps with the terminal position, the DBC limiting plate is placed on a base plate, and has placed DBC and DBC soldering lug in the DBC limiting plate.

2. The welding positioning assembly for the power terminals of the IGBT module according to claim 1, wherein two terminal grooves are symmetrically formed on both sides of the hollow groove, and vertical strip-shaped protrusions are arranged on the edges of the two sides of the terminal spacing limit, and the thickness of the vertical strip-shaped protrusions is matched with the depth of the terminal grooves.

3. The welding positioning assembly for the IGBT module power terminal according to claim 1, wherein a plurality of positioning holes are formed on the surface of the DBC limiting plate, and the terminal position limiting part is fixed in the positioning holes through positioning pins.

4. The IGBT module power terminal weld locating component of claim 1, wherein the top of the terminal spacing block is provided with a circular hole.

5. The IGBT module power terminal weld locating assembly of claim 1, wherein the terminal spacing and terminal position limits are sized according to power terminal spacing requirements.

6. The IGBT module power terminal welding position assembly of claim 1, wherein the number of the hollowed grooves is three, and the three hollowed grooves are arranged equidistantly and symmetrically on the terminal position limiting surface.

7. The IGBT module power terminal welding positioning assembly according to claim 1, wherein the power terminal set with soldering lug comprises two power terminals with soldering lugs, the power terminal set with soldering lugs comprises a power terminal with a circle of which the bottom wraps the bottom of the terminal soldering lug, and the width of the terminal soldering lug is less than 0.5mm of the width of the power terminal.

8. A welding positioning method for an IGBT module power terminal is characterized by comprising the following steps:

placing the DBC limiting plate on the substrate;

sequentially placing a DBC soldering lug and a DBC into the DBC limiting plate based on the placement position of the DBC limiting plate;

the terminal position limit is fixed on a corresponding locating hole on the DBC limiting plate through a locating pin;

placing the power terminal group with the soldering lug into the hollowed groove for limiting the position of the terminal according to the position limiting and placing direction of the terminal;

and spacing and placing the terminal space between the two power terminals with soldering lugs in each hollowed groove.

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