Thick film heater plate and electrode encapsulation welding structure

Abstract

The utility model discloses a kind of thick film heating plate and electrode plastic package welding structure. It includes multiple side-by-side copper electrodes and corresponding thick film plate circuit welded with copper electrode, thick film plate circuit is arranged on thick film heating plate;Each copper electrode includes the welding section of front part, the cladding section of middle part and the lead-out section of rear part;The end of welding section is equipped with notched, the outer surface of cladding section is covered with insulating injection-molded shell, the front section of welding section is equipped with the convex point of convex lower surface, the top of convex point is limited on thick film plate circuit so that welding section and the welding gap between the welding surface of thick film plate circuit are formed.Advantages are: improve the filling quality and wetting performance of solder, improve the compactness and interface bonding strength of weld point, thereby overall enhance the welding reliability between electrode and thick film heating plate.

Description

Technical Field

[0001] This utility model relates to the application field of thick film heaters, a core component of thermal management in new energy vehicles, and in particular to a welding structure of a thick film heating plate and an electrode plastic-coated part. Background Technology

[0002] The rapid development of new energy vehicles (NEVs) has created vast application opportunities for thick-film heating technology. Thick-film heaters, with their advantages of high efficiency, energy saving, rapid response, compact structure, and long lifespan, are gradually replacing traditional PTC heating solutions and becoming one of the core components of the thermal management system for new energy vehicles. However, poor welding between the thick-film heating plate and the electrode coating can lead to a series of serious consequences, affecting electrical performance, safety, reliability, and service life.

[0003] The specific analysis points are as follows: ① Electrical performance failure: Weak or poor welding can lead to increased contact resistance between the electrode and the thick film circuit, local overheating, or even circuit burnout. In the heating system of new energy vehicle batteries, this may cause a decrease in heating efficiency and an inability to heat up quickly in low-temperature environments; ② Safety hazards: Short circuits and arc discharges, poor welding leading to loose electrodes, metal parts contacting other conductors (such as plastic parts touching the outer shell after melting through), insulation failure, high welding temperatures causing local carbonization of the plastic-coated parts, or weld burrs piercing the insulation layer; ③ Mechanical reliability issues: Weld fatigue under vibration, continuous vibration during vehicle operation may cause poor weld point breakage (such as electrode detachment from seat heaters); ④ Decreased durability and lifespan: Incompletely sealed welds allow moisture intrusion, leading to electrode oxidation (such as blackening of the silver paste layer due to sulfidation), continuous overheating in poorly welded areas, accelerating plastic embrittlement or thick film layer peeling. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a welding structure for a thick film heating plate and an electrode coated part that results in stronger welding, better high-temperature resistance, and reduced weld porosity.

[0005] To solve the above-mentioned technical problems, the thick film heating plate and electrode plastic-coated part welding structure of this utility model includes multiple copper electrodes arranged side by side and thick film plate circuits welded to the copper electrodes. The thick film plate circuits are set on the thick film heating plate. Each copper electrode includes a front welding section, a middle coating section and a rear lead-out section. The end of the welding section is provided with a groove. The outer surface of the coating section is covered with an insulating injection-molded shell. The front section of the welding section is provided with a protrusion on the lower surface. The top of the protrusion is limited on the thick film plate circuit so that a welding gap is formed between the welding section and the welding surface of the thick film plate circuit.

[0006] The welding gap ranges from 0.1 to 0.2 mm.

[0007] The insulating injection-molded housing is made of PPS or PA66 composite material.

[0008] The surface of the copper electrode is tin-plated.

[0009] The slot is U-shaped.

[0010] The protrusion is in the shape of an "○".

[0011] The outer edge of the insulating injection molded shell is provided with fixing holes for fixing the thick film heating plate. The insulating injection molded shell is connected and fixed to the thick film heating plate by screws passing through the fixing holes.

[0012] The mounting surface of the insulating injection-molded shell and the thick film heating plate is provided with a limiting block that makes the insulating injection-molded shell and the thick film heating plate parallel to each other.

[0013] Advantages of this utility model: (1) The surface of the copper electrode is tin-plated to improve the welding strength. The copper electrode is covered with an insulating injection molded shell. PPS or PA66+30% glass fiber can make it withstand high temperature above 150℃ to prevent local carbonization of the plastic-coated part due to high welding temperature, or burrs of the solder joint piercing the insulation layer. (2) Compared with the traditional openless, rectangular electrode end design, the copper electrode end is provided with a "U" shaped groove and "○" shaped protrusion, which increases the welding area and improves the welding strength. In addition, the bottom surface of the insulating injection molded shell is provided with a limiting block to ensure that the insulating injection molded shell and the thick film heating plate are in the same plane welding gap. (3) By forming a welding gap between the “U”-shaped groove and the “○”-shaped protrusion, and controlling the welding gap within the range of 0.1 mm to 0.2 mm, the melting efficiency and filling uniformity of the solder (such as brazing filler metal or solder wire) during the welding process can be effectively improved, and the porosity of the solder joint can be significantly reduced. Among them, the solder is subjected to capillary effect in the gap between the “U”-shaped groove and the “○”-shaped protrusion, and can spontaneously penetrate and flow evenly into the weld gap, effectively expelling air and reducing the generation of pores. The capillary effect refers to the phenomenon that liquid spontaneously flows in a narrow gap due to surface tension and adhesion. The capillary effect significantly improves the filling quality and wetting performance of the solder, enhances the density and interface bonding strength of the solder joint, and thus enhances the overall welding reliability between the electrode and the thick film heating plate. Attached Figure Description

[0014] Figure 1 This is a side view of the copper electrode in the welded structure of the thick film heating plate and the electrode plastic-coated part of this utility model; Figure 2 This is a bottom view of the copper electrode in the welded structure of the thick film heating plate and the electrode plastic-coated part of this utility model; Figure 3This is a side view of the welding assembly of the copper electrode and the thick film heating plate in the welding structure of the thick film heating plate and the electrode plastic-coated part of this utility model; Figure 4 This is an enlarged schematic diagram of the welding section in the welding structure of the thick film heating plate and the electrode plastic-coated part of this utility model; Figure 5 This is a front view of the copper electrode in the welded structure of the thick film heating plate and the electrode plastic-coated part of this utility model; Figure 6 This is a rear view of the assembly of the thick film heating plate and the electrode plastic-coated part of this utility model. Figure 7 This is a top view of the assembly of the thick film heating plate and the electrode plastic-coated part of this utility model. Detailed Implementation

[0015] The following detailed description of the welding structure of the thick film heating plate and the electrode plastic-coated part of this utility model, in conjunction with the accompanying drawings and specific embodiments, will be further provided. Example

[0016] The thick-film heating plate and electrode-coated plastic welding structure includes multiple copper electrodes 2 arranged side by side and thick-film board circuits welded to the copper electrodes 2 respectively. The surface of the copper electrodes 2 is tin-plated. The thick-film board circuit is set on the thick-film heating plate 8. Each copper electrode 2 includes a front welding section 3, a middle covering section 4, and a rear lead-out section 5. The outer surface of the covering section 4 is covered with an insulating injection-molded shell 1 made of PPS or PA66 composite material (PA66 + 30% glass fiber material). The front section of the welding section 3 has an "O"-shaped protrusion 6 protruding from the lower surface. The top of the protrusion 6 is limited on the thick-film board circuit, so that a welding gap is formed between the welding section 3 and the welding surface of the thick-film board circuit. The welding gap ranges from 0.1 to 0.2 mm. The end of the welding section 3 is provided with a U-shaped groove 7. The U-shaped groove has a larger welding area than the rectangular welding section without a groove, and the welding strength is significantly improved. During the welding process, the solder (brazing filler or solder wire) dissolves better in the welding gap, solving the problem of poor welding points. Through the capillary effect, the air inside the flowing solder joint is not easily broken, reducing the porosity of the solder joint. The capillary effect refers to the phenomenon of spontaneous flow of liquid in narrow pipes or gaps due to surface tension. In the welding process of the thick film heating plate 8 and the insulating injection molded shell 1, the capillary effect has a significant impact on key process links such as solder filling, porosity control, and interface bonding strength. The outer edge of the insulating injection molded shell 1 is provided with a fixing hole 9 for fixing the thick film heating plate 8. The insulating injection molded shell 1 is connected and fixed to the thick film heating plate 8 by screws 10 passing through the fixing hole 9, which makes it less likely to cause welding defects such as misalignment during the welding process. The mounting surface of the insulating injection molded shell 1 and the thick film heating plate 8 is provided with a limiting block 11 that makes the insulating injection molded shell 1 and the thick film heating plate 8 parallel to each other, ensuring the welding gap.

Claims

1. A welding structure for a thick-film heating plate and an electrode coated with plastic, characterized in that: It includes multiple copper electrodes (2) arranged side by side and thick film plate circuits welded to the copper electrodes (2), the thick film plate circuits being disposed on a thick film heating plate (8); each copper electrode (2) includes a front welding section (3), a middle covering section (4) and a rear lead-out section (5); the end of the welding section (3) is provided with a slot (7), the outer surface of the covering section (4) is covered with an insulating injection molded shell (1), the front section of the welding section (3) is provided with a protrusion (6) protruding from the lower surface, the top of the protrusion (6) is limited on the thick film plate circuit so that a welding gap is formed between the welding section (3) and the welding surface of the thick film plate circuit.

2. The welding structure of the thick film heating plate and the electrode plastic-coated part according to claim 1, characterized in that: The welding gap ranges from 0.1 to 0.2 mm.

3. The welding structure of the thick film heating plate and the electrode plastic-coated part according to claim 1, characterized in that: The insulating injection-molded housing (1) is made of PPS or PA66 composite material.

4. The welding structure of the thick film heating plate and the electrode plastic-coated part according to claim 1, characterized in that: The surface of the copper electrode (2) is tin-plated.

5. The welding structure of the thick film heating plate and the electrode plastic-coated part according to claim 1, characterized in that: The slot (7) is U-shaped.

6. The welding structure of the thick film heating plate and the electrode plastic-coated part according to claim 1, characterized in that: The protrusion (6) is in the shape of "○".

7. The welding structure of the thick film heating plate and the electrode plastic-coated part according to claim 1, characterized in that: The outer edge of the insulating injection molded shell (1) is provided with a fixing hole (9) for fixing the thick film heating plate (8). The insulating injection molded shell (1) is connected and fixed to the thick film heating plate (8) by a screw (10) passing through the fixing hole (9).

8. The welding structure of the thick film heating plate and the electrode plastic-coated part according to claim 1, characterized in that: The insulating injection molded shell (1) and the thick film heating plate (8) are provided with a limiting block (11) that makes the insulating injection molded shell (1) and the thick film heating plate (8) parallel to each other.

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