阅读说明：本技术 一种负重针及其在轴向玻璃封装热敏电阻烧结中的应用 (Load bearing needle and application thereof in axial glass packaging thermistor sintering ) 是由 阴卫华 周好 周善喜 孙振 石宇 姜潘 阴启蓬 于 2019-09-23 设计创作，主要内容包括：本发明公开了一种负重针及其在轴向玻璃封装热敏电阻烧结中的应用,所述负重针包括圆柱体,所述圆柱体的一端设有盲孔,所述圆柱体的另一端为锥形或拱形。本发明提供的负重针可以稳定的罩在热敏电阻的引线上,无需石墨模具的固定,也就不需要负重针石墨模具与热敏电阻一起进行烧结,避免了石墨模具烧结产生的各种弊端。(The invention discloses a load-bearing needle and application thereof in axial glass-encapsulated thermistor sintering. The load bearing needle provided by the invention can stably cover the lead wire of the thermistor without fixing the graphite die, so that the load bearing needle graphite die and the thermistor are not required to be sintered together, and various defects caused by sintering of the graphite die are avoided.)

1. The weight needle is characterized by comprising a cylinder (1), wherein a blind hole (2) is formed in one end of the cylinder (1).

2. Weight needle according to claim 1, characterized in that the other end of the cylinder (1) is conical or arched.

3. Weight pin according to claim 1 or 2, characterized in that the blind hole (2) is a cylindrical blind hole, the blind hole (2) being arranged coaxially to the cylindrical body (1).

4. Weight needle according to claim 3, characterized in that the blind hole (2) has a hole diameter of 0.9-1.3mm and the blind hole (2) has a hole depth of 2.5-3 mm.

5. A weight-bearing needle according to claim 4, characterized in that the diameter of the cylindrical body (1) is 2.7-3.2mm and the height of the cylindrical body (1) is 5.5-7 mm.

6. The weight-bearing needle of claim 1, wherein the weight-bearing needle is made of ceramic.

7. Use of a weight pin according to any one of claims 1 to 6 in sintering of an axial glass-encapsulated thermistor, characterized in that the method of use is: and placing the axial glass-encapsulated thermistor (3) to be sintered into a sintered graphite die (4), covering the load with a needle on an upper lead (3.1) of the axial glass-encapsulated thermistor (3) to be sintered, and enabling the top end of the upper lead (3.1) to be positioned in the blind hole (2) for sintering.

8. Use of a load needle in the sintering of an axial glass-encapsulated thermistor according to claim 7, characterized in that the process of covering the upper lead wire (3.1) with the load needle is done by a load needle mold fit.

9. The use of a weight pin in sintering an axial glass encapsulated thermistor according to claim 8, characterized in that the weight pin mold comprises a graphite plate (5), the graphite plate (5) is provided with weight pin grooves (6) on the plate surface, and the weight pin grooves (6) are matched with the weight pin.

10. Use of a weight pin according to claim 9 in sintering of an axial glass-encapsulated thermistor, characterized in that the graphite plate (5) is provided with at least two positioning holes (7).

Technical Field

The invention relates to the field of thermistors, in particular to a load bearing needle and application thereof in axial glass packaging thermistor sintering.

Background

The thermistor is a temperature-sensitive resistor element, which shows different resistance values at different temperatures, and is used as a common component of a temperature sensor. According to different arrangement modes of the lead wires, the resistors can be divided into axial lead wire thermistors, radial lead wire thermistors and chip resistors without lead wires.

The main structure of the axial glass-packaged thermistor comprises a chip, a lead wire and a glass sleeve, wherein the sintering process is to sinter a semi-finished product in a high-temperature sintering furnace to ensure that the glass sleeve is melted and wrapped outside the chip and the lead wire to form a compact glass wrapping layer. In the sintering process, in order to guarantee that upper and lower lead wire and chip contact are good, can press the heavy needle on the upper lead wire, current heavy needle is stainless steel's cylinder, because it can not stably fix alone on the upper lead wire, need cooperate graphite mold to use together. The graphite die, the stainless steel heavy needle and the thermistor are placed into a high-temperature sintering furnace together for sintering, and the graphite can generate dust during high-temperature sintering, so that the service life of the die is influenced, the cleaning is difficult, and the production environment is influenced. In order to avoid the problem, some manufacturers do not use a load-bearing needle, and only rely on the self-weight of the upper lead to press on the joint of the chip and the lead, but the connection of the chip and the lead is affected, so that the reject ratio of the product is increased.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a load bearing needle and application thereof in axial glass packaging thermistor sintering, the load bearing needle can be stably covered on a lead wire of a thermistor without fixing a graphite mold, and various defects caused by sintering of the graphite mold are avoided.

The invention provides a load bearing needle which is characterized by comprising a cylinder, wherein a blind hole is formed in one end of the cylinder.

Preferably, the other end of the cylinder is tapered or arched.

Preferably, the blind hole is a cylindrical blind hole, and the blind hole is arranged coaxially with the cylinder.

Preferably, the aperture of the blind hole is 0.9-1.3mm, and the depth of the blind hole is 2.5-3 mm.

Preferably, the diameter of the cylinder is 2.7-3.2mm and the height of the cylinder is 5.5-7 mm.

Preferably, the weight-bearing needle is made of ceramic.

The invention also provides an application of the load needle in axial glass packaging thermistor sintering, and the application method comprises the following steps: and placing the axial glass-packaged thermistor to be sintered into a sintered graphite die, covering the load needle on an upper lead of the axial glass-packaged thermistor to be sintered, and enabling the top end of the upper lead to be positioned in the blind hole for sintering.

Preferably, the process of placing the weight needle shield on the guide wire is accomplished by a weight needle mold fit.

Preferably, the weight-bearing needle mold comprises a graphite plate, a weight-bearing needle groove is formed in the plate surface of the graphite plate, and the weight-bearing needle groove is matched with the weight-bearing needle.

Preferably, at least two positioning holes are formed in the graphite plate.

The loading needle provided by the invention is provided with the blind hole, can be stably covered on the lead wire of the thermistor, and does not need to be fixed by a graphite mold, so that the loading needle and the graphite mold are not required to be sintered together, and various defects generated after the graphite mold is sintered are avoided.

The load-bearing needle provided by the invention can be used independently, but is preferably matched with a load-bearing needle mold to be used together for improving the production efficiency, the load-bearing needle grooves on the load-bearing needle mold provided by the invention correspond to the arrangement of the thermistors on the sintered graphite mold of the thermistors one by one, and the load-bearing needle mold can be used for covering all the thermistors on one pair of sintered graphite molds with load-bearing needles at one time.

In order to facilitate the loading of the loading needle into the loading needle mould, the end of the loading needle opposite to the blind hole is preferably in a conical or arched structure. The loading needle mold is characterized in that a plurality of loading needles are sprinkled on the plate surface of the loading needle mold, the loading needle mold is shaken leftwards and rightwards, due to the fact that one end of each loading needle is provided with a blind hole, and the other end of each loading needle is of a conical or arched structure, the loading needles can automatically fall into the loading needle grooves under the influence of gravity, shape and structure, the loading needle mold is simple in loading process and easy to operate, and the loading needle mold is suitable for being applied to batch production of thermistors.

Drawings

FIG. 1 is a cross-sectional view of a weight-bearing needle provided by the present invention.

FIG. 2 is a schematic view of the loading pin of the present invention in use in sintering an axial glass-encapsulated thermistor.

FIG. 3 is a schematic diagram of the structure of the weight pin template of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in figure 1, the invention provides a weight-bearing needle which comprises a cylindrical body 1, wherein one end of the cylindrical body 1 is provided with a blind hole 2.

The other end of the cylinder 1 is conical or arched.

The blind hole 2 is a cylindrical blind hole, and the blind hole 2 is coaxial with the cylinder 1.

The aperture of the blind hole 2 is 0.9-1.3mm, and the aperture of the blind hole 2 in the embodiment is preferably 1.0mm, 1.1mm or 1.2 mm. The depth of the blind hole 2 is 2.5-3mm, and the depth of the blind hole 2 in the embodiment is preferably 2.6mm, 2.7mm, 2.8mm or 2.9 mm.

The diameter of the cylinder 1 is 2.7-3.2mm, and the diameter of the cylinder 1 in the embodiment is preferably 2.8mm, 2.9mm, 3.0mm or 3.1 mm. The height of the cylinder 1 is 5.5-7mm, and the height of the cylinder 1 in this embodiment is preferably 5.7mm, 5.9mm, 6.0mm, 6.2mm, 6.4mm, 6.6mm or 6.8 mm.

The weight of the weight-bearing needle is more than 2 times of the weight of a single lead of the axial glass-packaged thermistor, and the weight of the weight-bearing needle in the embodiment is preferably 3 times, 4 times, 5 times, 6 times, 8 times, 10 times, 15 times or 20 times of the weight of the single lead of the axial glass-packaged thermistor.

The weight-bearing needle is made of a material which can resist the high temperature of more than 600 ℃, the material can not be melted and deformed after being sintered for 3 hours at the temperature of 600 ℃, and the weight-bearing needle is preferably made of ceramics.

The invention also provides an application of the load needle in axial glass packaging thermistor sintering, and the application method comprises the following steps: and placing the axial glass-packaged thermistor 3 to be sintered into a sintered graphite die 4, covering the load needle on an upper lead 3.1 of the axial glass-packaged thermistor 3 to be sintered, and enabling the top end of the upper lead 3.1 to be positioned in the blind hole 2 for sintering.

The sintered graphite mold 4 of the present invention is made by the prior art.

The upper lead 3.1 is a lead which is positioned above the axial glass-packaged thermistor during sintering.

The process that the weight needle covers the upper lead wire 3.1 is completed through the matching of a weight needle mold, the weight needle mold comprises a graphite plate 5, a weight needle groove 6 is formed in the surface of the graphite plate 5, the weight needle groove 6 is matched with the weight needle, and when the weight needle is arranged in the weight needle groove, the opening end of the blind hole 2 of the weight needle faces outwards. The distribution of the load needle grooves corresponds to the distribution of the axial glass-encapsulated thermistors 3 to be sintered on the sintered graphite mold 4 one by one.

Two positioning holes 7 are formed in the graphite plate 5. The position of the positioning hole 7 corresponds to the position of the positioning hole on the sintered graphite mold 4.

The application method of the load needle and the load needle mould in the axial glass packaging thermistor sintering comprises the following steps:

s1, placing the axial glass packaging thermistor to be sintered into a sintered graphite die;

s2, loading the weight needle into the weight needle groove of the weight needle mould, wherein the specific method comprises the following steps: spraying a plurality of weight needles on the plate surface of the weight needle mold, and shaking the weight needle mold left and right to automatically drop the weight needles into the weight needle grooves;

s3, placing the sintered graphite mold with the axial glass packaged thermistor to be sintered and the load needle mold with the load needles correspondingly, wherein the positioning holes of the sintered graphite mold correspond to the positioning holes of the load needle mold one by one, adjusting the orientation to enable all the load needles on the load needle mold to cover the axial glass packaged thermistor to be sintered at one time, removing the load needle mold, and sintering.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.