A substrate for semiconductor thermoelectric device and semiconductor thermoelectric device

Abstract

The present invention discloses a substrate and a semiconductor electric heating element for a semiconductor thermoelectric device, wherein the substrate comprises a substrate plate, wherein the top surface of the substrate plate is provided with a lead guide plate, wherein the lead guide plate is divided into a particle welding area and a lead welding area, wherein a solder resist area is provided between the particle welding area and the lead welding area; wherein the solder resist area is provided with a solder resist groove, wherein the solder resist groove does not completely separate the particle welding area and the lead welding area, that is, the solder resist groove does not penetrate the solder resist area. The solder resist groove that does not completely separate the particle welding area and the lead welding area is provided in the solder resist area, which can not only prevent the solder from flowing across the boundary, but also prevent the short circuit between the particle welding area and the lead welding area caused by the error of the processing technology, thereby improving the product quality.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor refrigeration, and in particular to a substrate for a semiconductor thermoelectric device and a semiconductor thermoelectric device. Background Art

[0002] Semiconductor thermoelectric devices are usually composed of a lower substrate, an upper substrate and a PN couple pair (i.e., particles) arranged between the upper and lower substrates. A lead welding area and a particle welding area are arranged on the lower substrate, and leads are welded in the lead area to facilitate the connection of the semiconductor thermoelectric device to an external circuit.

[0003] Since the lead welding area and particle welding area of ​​semiconductor thermoelectric devices are usually located on the same guide plate, the distance between the two is short. During welding, the solder applied on the particle welding area easily overflows and flows to the lead welding area, causing regional short circuit problems and resulting in product scrapping.

[0004] In the prior art, a full cutting method is usually used to form a solder mask groove, that is, a through cut is made between the lead welding area and the particle welding area to achieve solder blocking. However, in the operation of this solder mask method, due to errors in the processing technology, such as uneven substrate thickness, or the influence of factors such as the tilt of the substrate during cutting, it is easy to cut through the metal layer of the drain plate (the drain plate is a metal coating with a small thickness), resulting in a disconnection between the lead welding area and the particle welding area, resulting in product scrapping. Summary of the invention

[0005] The purpose of the present invention is to provide a substrate for a semiconductor thermoelectric device, in which a solder resist groove that does not completely isolate a particle welding area and a lead welding area is set in the solder resist area, which can not only prevent the solder from flowing across the boundary, but also prevent the short circuit between the particle welding area and the lead welding area caused by errors in the processing technology, thereby improving product quality.

[0006] Another object of the present invention is to provide a semiconductor thermoelectric device, which adopts the above-mentioned substrate to improve product quality.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] A substrate for a semiconductor thermoelectric device comprises a substrate plate, wherein a lead guide plate is provided on the top surface of the substrate plate, wherein the lead guide plate is divided into a particle welding area and a lead welding area, and a solder resist area is provided between the particle welding area and the lead welding area;

[0009] The solder resist area is provided with a solder resist groove, and the solder resist groove does not completely separate the particle welding area and the lead welding area, that is, the solder resist groove does not completely penetrate the solder resist area.

[0010] Furthermore, the lead guide plate includes a first metal layer, a second metal layer and a third metal layer arranged in sequence from bottom to top;

[0011] The depth of the solder resist groove is H1, the thickness of the third metal layer is H2, and the thickness of the second metal layer is H3, H2≤H1<H2+H3.

[0012] Furthermore, the length of the solder resist groove is greater than half of the length of the solder resist area and less than the length of the solder resist area.

[0013] Furthermore, there are a plurality of solder resist grooves, and the plurality of solder resist grooves are parallel to each other.

[0014] Furthermore, the solder resist groove is formed by laser cutting.

[0015] Furthermore, the length of the solder resist groove is greater than or equal to half of the length of the solder resist area, and less than the length of the solder resist area.

[0016] Furthermore, the plurality of solder resist grooves are divided into a first solder resist groove and a second solder resist groove;

[0017] The first solder resist groove extends from the first end to the second end of the solder resist area, the second solder resist groove extends from the second end to the first end of the solder resist area, and the first solder resist groove and the second solder resist groove are alternately arranged;

[0018] The first end and the second end of the solder resist area are opposite ends, and the distance between the first end and the second end of the solder resist area is the length of the solder resist area.

[0019] Furthermore, the first metal layer is a copper layer, the second metal layer is a nickel layer, and the third metal layer is a gold layer.

[0020] Furthermore, a palladium layer is provided between the nickel layer and the gold layer, and the palladium layer and the gold layer are classified as the third metal layer.

[0021] A semiconductor thermoelectric device comprises an upper substrate, a lower substrate and a semiconductor element, wherein the semiconductor element is welded between the upper substrate and the lower substrate, and the lower substrate is the above-mentioned substrate for the semiconductor thermoelectric device;

[0022] The particle welding area is used for welding the semiconductor electric heating device, and the lead welding area is used for welding the lead.

[0023] The beneficial effects of the embodiments of the present invention are:

[0024] 1. A solder resist groove is obtained by laser cutting in the solder resist area between the particle welding area and the lead welding area. The solder resist groove does not completely separate the particle welding area and the lead welding area. The solder resist area can prevent the flow of solder, eliminate the regional short circuit phenomenon caused by the overflow of solder when the lead welding area and the particle welding area are welded, and can also avoid the circuit breaking caused by the completely cut solder resist groove structure in the prior art;

[0025] 2. The surface wettability of the inner wall of the solder mask groove obtained by laser cutting is different from that of the lead welding area and the particle welding area, which plays a role in blocking the solder. The solder mask groove can also play a role in containing the solder;

[0026] 3. Multiple solder mask grooves can further improve the solder blocking effect and provide higher reliability for solder blocking. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of a substrate for a semiconductor thermoelectric device according to an embodiment of the present invention;

[0028] Figure 2 yes Figure 1 A schematic cross-sectional view of the substrate shown;

[0029] Figure 3 is a schematic structural diagram of a substrate for a semiconductor thermoelectric device according to another embodiment of the present invention;

[0030] Figure 4 yes Figure 3 A schematic cross-sectional view of the substrate shown;

[0031] Figure 5 is a schematic structural diagram of a substrate for a semiconductor thermoelectric device according to another embodiment of the present invention;

[0032] Figure 6 yes Figure 5 A schematic cross-sectional view of the substrate shown;

[0033] In the attached figure:

[0034] 01-upper substrate, 02-lower substrate, 03-semiconductor element, 1-substrate plate, 2-lead guide plate, 3-particle welding area, 4-lead welding area, 5-solder resist area, 6-solder resist groove, 61-first solder resist groove, 62-second solder resist groove, 21-first metal layer, 22-second metal layer, 23-third metal layer. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0036] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of the features, and are used to distinguish and describe features, without distinction of order or importance.

[0037] In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Combine the following Figures 1 to 6 , describing a substrate for a semiconductor thermoelectric device and a semiconductor thermoelectric device according to an embodiment of the present invention.

[0040] A substrate for a semiconductor thermoelectric device according to an embodiment of the present invention comprises a substrate plate 1, a top surface of the substrate plate 1 is provided with a lead guide plate 22, the lead guide plate 22 is divided into a particle welding area 3 and a lead welding area 4, a solder resist area 5 is provided between the particle welding area 3 and the lead welding area 4;

[0041] The solder resist region 5 is provided with a solder resist groove 6 , which does not completely separate the particle welding region 3 and the lead welding region 4 , that is, the solder resist groove does not completely penetrate the solder resist region 5 .

[0042] The solder resist area 5 between the particle welding area 3 and the lead welding area 4 is cut by laser to obtain a solder resist groove 6, which does not completely separate the particle welding area 3 and the lead welding area 4. The solder resist area 5 can prevent the flow of solder, eliminate the regional short circuit phenomenon caused by the overflow of solder when the lead welding area 4 is welded with the particle welding area 3, and avoid the circuit breaking caused by the completely cut solder resist groove 6 structure in the prior art.

[0043] Preferably, the solder resist groove 6 is cut by laser, and the surface wettability of the inner wall of the solder resist groove 6 cut by laser is different from that of the lead welding area 4 and the particle welding area 3, which plays a role in blocking solder. The solder resist groove 6 can also play a role in accommodating solder.

[0044] Specifically, the top surface of the substrate plate 1 of the substrate of this embodiment is provided with a plurality of guide plate groups, the guide plate groups include a plurality of guide plates and two lead guide plates 2, the guide plates are used to weld the semiconductor elements 03, and the two lead guide plates 2 are used to connect the leads to realize the current in and out.

[0045] Specifically, the lead guide plate 2 includes a first metal layer 21, a second metal layer 22 and a third metal layer 23 arranged in sequence from bottom to top. The first metal layer 21 is a copper layer, which is convenient for semiconductor element 03 or lead welding. The second metal layer 22 is a nickel layer, which is used to prevent the diffusion of two adjacent metal layers. The third metal layer 23 is a gold layer, which plays a conductive role. Preferably, a palladium layer is also provided between the nickel layer and the gold layer, which can further improve the effect of preventing the diffusion of two adjacent metal layers. In the present invention, the palladium layer and the gold layer are classified as the third metal layer 23.

[0046] It should be noted that the lead guide plate in this embodiment uses three metal layers, but is not limited to three layers, and other metal layers may be provided between the metal layers in this embodiment, or between the substrate plate and the metal layers. For example, a titanium layer may be provided between the substrate plate and the first metal layer.

[0047] In order to make the solder resist groove 6 reach a certain depth to accommodate solder and prevent the solder resist groove 6 from being too deep to affect the conductive performance of the lead guide plate 2, further, the depth of the solder resist groove 6 is H1, the thickness of the third metal layer 23 is H2, and the thickness of the second metal layer 22 is H3, H2≤H1<H2+H3.

[0048] In order to achieve a better solder resist effect and ensure that the lead guide plate 2 has a conductive effect, the length of the solder resist groove 6 is greater than half of the length of the solder resist area 5 and less than the length of the solder resist area 5. One end of the solder resist groove 6 extends from one end of the solder resist area 5 to the other opposite end, and the distance between the two ends of the solder resist groove 6 is less than the length of the solder resist area 5. The connecting line of the two ends of the solder resist groove 6 is parallel to the length direction of the solder resist area 5. It should be noted that the distance between the two ends of the solder resist groove 6 refers to the length of the solder resist groove 6 located only on the lead guide plate 2. In other embodiments, the solder resist groove 6 can also be located in the middle of the solder resist area 5.

[0049] In some embodiments, the number of solder resist grooves 6 is multiple, which has a more reliable solder resist effect. In order to facilitate processing, the multiple solder resist grooves 6 are parallel to each other. The length of the solder resist groove 6 is greater than or equal to half of the length of the solder resist area 5, and is less than the length of the solder resist area 5. Based on the setting of multiple solder resist grooves 6, when the length of the solder resist groove 6 is equal to half of the length of the solder resist area 5, it still has a good solder resist effect.

[0050] Further, the plurality of solder resist grooves 6 are divided into a first solder resist groove 61 and a second solder resist groove 62; the first solder resist groove 61 extends from the first end to the second end of the solder resist area 5, and the second solder resist groove 62 extends from the second end to the first end of the solder resist area 5, and the first solder resist groove 61 and the second solder resist groove 62 are alternately arranged; the first end and the second end of the solder resist area 5 are opposite ends, and the distance between the first end and the second end of the solder resist area 5 is the length of the solder resist area 5. The first solder resist groove 61 and the second solder resist groove 62 arranged in this way can cover the entire length of the solder resist area 5, and effectively prevent the solder from flowing to the cross area without cutting off the solder resist area 5.

[0051] When the amount of solder in the particle welding area 3 or the lead welding area 4 is large, two, three or even more solder resist grooves 6 may be provided to achieve an excellent solder resist effect.

[0052] Correspondingly, a semiconductor thermoelectric device according to an embodiment of the present invention includes an upper substrate 01, an upper substrate 02 and a semiconductor element 03, wherein the semiconductor element 03 is welded between the upper substrate 01 and the upper substrate 02, and the upper substrate 02 is the above-mentioned substrate for the semiconductor thermoelectric device; the particle welding area 3 is used for welding the semiconductor thermoelectric device, and the lead welding area 4 is used for welding the lead.

[0053] Specifically, a plurality of guide plates are provided on the bottom surface of the upper substrate 01, and the semiconductor element 03 is welded between the guide plates of the upper substrate 01 and the guide plates of the upper substrate 02. The length of the upper substrate 02 is greater than that of the upper substrate 01, so that one end thereof extends out of the upper substrate 01, and the end of the lead guide plate 2 located on the upper substrate 02 is also exposed outside the upper substrate 01, so as to facilitate welding of the lead on the lead guide plate 2. Based on the design of the solder resist groove on the lead guide plate 2, the solder in the welding area of ​​the semiconductor element 03 is effectively blocked, thereby preventing short circuit and improving the product quality of the semiconductor thermoelectric device.

[0054] A substrate for a semiconductor thermoelectric device according to an embodiment of the present invention and other structures and operations of the semiconductor thermoelectric device are known to those skilled in the art and will not be described in detail here.

[0055] In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0056] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A substrate for a semiconductor thermoelectric device, It is characterized in that It comprises a substrate plate, wherein the top surface of the substrate plate is provided with a lead guide plate, the lead guide plate is divided into a particle welding area and a lead welding area, and a solder resist area is provided between the particle welding area and the lead welding area; The solder resist area is provided with a solder resist groove, and the solder resist groove does not completely separate the particle welding area and the lead welding area, that is, the solder resist groove does not completely penetrate the solder resist area; The lead guide plate comprises a first metal layer, a second metal layer and a third metal layer arranged in sequence from bottom to top; The depth of the solder resist groove is H1, the thickness of the third metal layer is H2, and the thickness of the second metal layer is H3, H2≤H1<H2+H3; The length of the solder resist groove is greater than or equal to one half of the length of the solder resist area, and less than the length of the solder resist area; The first metal layer is a copper layer, the second metal layer is a nickel layer, and the third metal layer is a gold layer.

2. The substrate for a semiconductor thermoelectric device according to claim 1, It is characterized in that There are multiple solder resist grooves, and the multiple solder resist grooves are parallel to each other.

3. The substrate for a semiconductor thermoelectric device according to claim 1, It is characterized in that The solder resist groove is formed by laser cutting.

4. The substrate for a semiconductor thermoelectric device according to claim 2, It is characterized in that The plurality of solder resist grooves are divided into a first solder resist groove and a second solder resist groove; The first solder resist groove extends from the first end to the second end of the solder resist area, the second solder resist groove extends from the second end to the first end of the solder resist area, and the first solder resist groove and the second solder resist groove are alternately arranged; The first end and the second end of the solder resist area are opposite ends, and the distance between the first end and the second end of the solder resist area is the length of the solder resist area.

5. The substrate for a semiconductor thermoelectric device according to claim 1, It is characterized in that A palladium layer is further disposed between the nickel layer and the gold layer, and the palladium layer and the gold layer are classified as the third metal layer.

6. A semiconductor thermoelectric device, It is characterized in that It comprises an upper substrate, a lower substrate and a semiconductor element, wherein the semiconductor element is welded between the upper substrate and the lower substrate, and the lower substrate is the substrate for a semiconductor thermoelectric device according to any one of claims 1 to 5; The particle bonding region is used for bonding the semiconductor element, and the lead bonding region is used for bonding leads.

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