CN211150217U - Packaging structure of PTC device - Google Patents
Packaging structure of PTC device Download PDFInfo
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- CN211150217U CN211150217U CN202020234856.6U CN202020234856U CN211150217U CN 211150217 U CN211150217 U CN 211150217U CN 202020234856 U CN202020234856 U CN 202020234856U CN 211150217 U CN211150217 U CN 211150217U
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Abstract
The utility model relates to a PTC device packaging structure, which comprises a PTC element, wherein the PTC element comprises a front electrode, a PTC sheet and a back electrode which are sequentially stacked; a hollow frame is surrounded by the side edge of the PTC element, and an insulating material is filled between the hollow frame and a gap of the side edge of the PTC element; the front electrode and the back electrode of the PTC element are respectively connected with the front electrode lead-out disc and the back electrode lead-out disc; the front electrode lead-out disc and the back electrode lead-out disc extend to the same surface of the packaging structure or are independently distributed on the side edge of the packaging structure. The PTC device with the novel structure and the processing method thereof solve the problems of low drilling efficiency, cutting burrs, poor reliability and the like.
Description
Technical Field
The utility model relates to a microelectronics packaging field especially relates to a packaging structure and packaging method of PTC device.
Background
The PTC is an abbreviation of Positive Temperature Coefficient (PTC), which can protect the circuit when the current surge is too large and the temperature is too high. When the device is used, the device is connected in series in a circuit, and under a normal condition, the resistance value and the loss of the device are very small, so that the normal work of the circuit is not influenced; however, if an overcurrent (such as a short circuit) occurs, the temperature of the circuit rises, and the resistance value of the circuit rises rapidly along with the temperature rise, so that the effect of limiting the current is achieved, and the components in the circuit are prevented from being damaged. Thus, the PTC device has a very wide range of applications.
At present, the structure of the PTC device in the industry is shown in fig. 1, metal electrodes are respectively arranged on two surfaces of a PTC sheet, and the PTC sheet between the two metal electrodes plays a role in increasing resistance at high temperature. The specific production process is that metal electrodes are respectively arranged on two surfaces of the PTC sheet, and then the circuit diagram of one surface is guided by the printed circuit board process of drilling, electroplating and resistance welding on the two surfaces of the PTC sheet for welding application. The prior art and the product have the following problems: (1) the PTC sheet core resin system is polyethylene which is a thermoplastic material and has strong toughness and is easy to deform at high temperature, so that the drilling efficiency is low, the drill bit is greatly damaged during the production and drilling, and the cost is high; (2) when the PTC device is cut, the metal electrode and the PTC material are mainly cut, and the device is easy to be wiredrawn to form glue burrs due to the strong toughness of the PTC material, so that the use of the rear section of the device is not facilitated; (3) the PTC material is exposed around the single PTC device, which has great influence on the reliability of the device.
In view of the above problems, it is desirable to provide a PTC device with a novel structure and a method for manufacturing the same to improve the problems of low drilling efficiency, burr cutting, poor reliability, etc.
Disclosure of Invention
The utility model discloses an invention aim at solve the packaging structure of current PTC device when processing and making drilling because of material toughness leads to drilling efficiency low, with high costs greatly, and the back end is used unusually and single device four sides exposes the PTC material and leads to it to have the reliability risk when there is the burr easily during the cutting. The concrete solution is as follows:
a packaging structure of a PTC device is characterized in that: comprises a PTC element, wherein the PTC element comprises a front electrode, a PTC sheet and a back electrode which are sequentially stacked; a hollow frame is surrounded by the side edge of the PTC element, and an insulating material is filled between the hollow frame and a gap of the side edge of the PTC element; the front electrode and the back electrode of the PTC element are respectively connected with the front electrode lead-out disc and the back electrode lead-out disc; the front electrode lead-out disc and the back electrode lead-out disc extend to the same surface of the packaging structure or are independently distributed on the side edge of the packaging structure.
Furthermore, the main material of the front electrode and the back electrode is any one of copper, nickel or copper-nickel alloy; the PTC sheet is an isotropic material and has positive temperature coefficient thermistor properties in the thickness direction, width direction and length direction of the PTC sheet.
Furthermore, the connection modes between the front electrode of the PTC element and the front electrode lead-out plate and between the back electrode of the PTC element and the back electrode lead-out plate include direct contact connection, conductive circuit + metal via connection.
Furthermore, the front electrode lead-out disc and the back electrode lead-out disc are located on the same plane of the packaging structure, the back electrode and the back electrode lead-out disc are connected in a direct contact mode, and the front electrode of the PTC element and the front electrode lead-out disc are connected in a conductive circuit plus a metal via hole.
Furthermore, the front electrode lead-out disc and the back electrode lead-out disc are independently distributed on the side face of the packaging structure, and the front electrode lead-out disc and the back electrode lead-out disc are connected through conductive circuits.
Furthermore, the area of the packaging structure except the front electrode lead-out disc and the back electrode lead-out disc is covered with an insulating material
Further, the hollow frame is a cured thermosetting resin material which is FR4 or BT material containing glass fiber.
A method of packaging a PTC device comprising the steps of:
(1) providing an insulating plate, forming a hollow area on the insulating plate, and finishing the processing of the hollow frame;
(2) placing the PTC element in the hollow area of the hollow frame, and sealing the bottom of the hollow frame by using a temporary bonding material to support the PTC element;
(3) filling insulating materials in gaps between the side edges of the PTC elements and the hollow frames, and removing the temporary bonding materials at the bottoms after the insulating materials are solidified to obtain frame materials;
(4) finishing the processing of the PTC element front electrode lead-out disc and the PTC element back electrode lead-out disc in the frame material in a physical or chemical mode;
(5) and covering the insulating material on the surface of the obtained material except the front electrode lead-out disc and the back electrode lead-out disc to finish the packaging of the PTC device.
Further, the processing of the front electrode lead-out tray and the back electrode lead-out tray in the step (4) includes the following two steps:
a, processing a through hole perpendicular to the plane of the PTC element in the insulating material at the side edge of the frame material; forming continuous conductive layers and metal through holes on the upper surface and the lower surface of the frame material and the inner side walls of the through holes in a copper deposition and electroplating mode, processing the conductive layers in a pattern circuit transfer mode, separating a back electrode lead-out disc and a front electrode lead-out disc on one surface of the frame material, and finishing the processing of the back electrode lead-out disc and the front electrode lead-out disc;
b, forming continuous conductive layers on the upper surface and the lower surface of the obtained frame material in a copper deposition and electroplating mode; processing the obtained conductive layer in a pattern circuit mode to form a conductive circuit and complete the leading-out of the front electrode and the back electrode of the PTC element; and the front lead-out disc and the back lead-out disc are processed by adopting a silver paste dipping or tin electroplating mode, so that the front lead-out disc and the back lead-out disc are respectively connected with the conductive circuits on the upper surface and the lower surface of the frame material and are independently distributed on the side edges of the frame material.
Further, the processing mode of the hollow area in the hollow frame comprises drilling, notching, groove milling and laser; the size of the hollow area needs to be larger than that of the PTC element, the hollow area can be designed according to the actual required size, and the size difference is usually controlled to be 60-100 mu m.
Further, the temporary bonding material is a material having a function of temporarily adhering and fixing the PTC element, which can be peeled off by a physical or chemical means.
Further, an insulating material is filled between the hollow frame and the PTC element, and the insulating material can be a liquid material or a sheet material; the filling mode can be silk-screen printing, blade coating, point coating or pressing and the like.
Furthermore, the copper deposition and electroplating manner to form the conductive layer means that metal is deposited on the surfaces of the insulating material and the conductive material in an undifferentiated manner, and the conductive metal is further thickened in an electroplating manner to ensure the conductive and heat dissipation capabilities; the metal deposition mode can be formed by sputtering, evaporation or chemical plating.
Further, the pattern circuit transfer mode specifically means that a layer of temporary protection material is covered on the surface of the whole conductive layer;
according to the design of the pattern circuit, removing part of the temporary protective material in an exposure and development mode, wherein the part covered by the protective material is a conductive part required by design, and the part covered by the protective material is removed to be an unnecessary conductive part;
removing the metal layer of the unnecessary conductive part by adopting a chemical liquid corrosion mode;
and removing the temporary protective material by using chemical liquid to finish the processing of the conducting circuit.
The utility model also provides a PTC device of processing through above-mentioned method.
To sum up, adopt the utility model discloses a technical scheme has following beneficial effect:
the utility model provides a solve the packaging structure of current PTC device when processing and making drilling because of material toughness leads to drilling efficiency low, with high costs greatly, there is the burr during cutting easily and leads to the back end to use unusually, and the problem that single device four sides reveal the PTC material and lead to it to have the reliability risk. This scheme of adoption has following advantage:
the PTC material does not need to be drilled, so that the processing efficiency of the PTC device can be greatly improved;
the PTC material wraps the black insulating material and the insulating frame all around, so the PTC material can greatly improve the reliability because of the protection of the insulating material, and meanwhile, because the side wall has a protective material, no wire drawing field exists when cutting is carried out, the edge of the device is more neat, and the use of subsequent products is facilitated.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed to be used in the description of the embodiments of the present invention will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive faculty.
FIG. 1 is a cross-sectional view of a conventional PTC device of the present invention
FIG. 2 is a flow chart of a method for manufacturing a PTC device according to the present invention
Fig. 3 is a cross-sectional view of one embodiment of a PTC device of the present invention
FIG. 4 is a flow chart of another method of manufacturing a PTC device according to the present invention
Fig. 5 is a cross-sectional view of another embodiment of a PTC device of the present invention
In the figure:
1-PTC sheet material; 2-a front electrode; 3-a back electrode; 4-hollowing out the frame; 5-an insulating material; 6-conductive lines; 7-metal via holes; 8-front electrode lead-out tray; 9-Back electrode lead-out tray.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
It should be noted that all the drawings in the present disclosure are cross-sectional structural diagrams, and the drawings are only for assisting understanding of the inventive concept and the structural principle of the present disclosure, and are not equal to physical products.
The technical solution of the present invention will be further explained by the following embodiments with reference to fig. 1 to 5.
The embodiment of the utility model provides an in PTC device preparation method, the concrete flow of this embodiment is as follows:
step S1: and providing an insulating plate, forming a hollow area on the insulating plate, and finishing the processing of the hollow frame 4.
In this embodiment, the insulating plate is a cured thermosetting resin, which is FR4 or BT material containing glass fiber, the thickness of the insulating material is equal to or greater than that of the PTC element, and the height difference is optimally controlled to be 0-20 μm to ensure the subsequent processing effect.
The hollow area is formed on the insulating plate, the forming mode can be any mode of drilling, punching, milling or laser, the size of the hollow area needs to be larger than that of the PTC element, the design can be carried out by combining the actual size of the PTC element and the placement deviation of the PTC element, and the difference between the size of the hollow area and the size of the PTC element needs to be controlled within 60-100 mu m under normal conditions so as to ensure the maximization of performance.
Step S2: and placing the PTC element in the hollow area of the hollow frame, and sealing the bottom of the hollow frame by using a temporary bonding material to support the PTC element.
In the embodiment, the temporary bonding glue is adopted at the bottom of the frame for sealing, so that the normal placement of the PTC element is ensured, and the PTC element is fixed; the temporary bonding material can wholly seal the insulating plate, and can also only seal the hollow position of the insulating plate; a generally common temporary bonding material may be a pyrolytically or mechanically removable material.
The PTC element in the embodiment is composed of a front electrode 2, a PTC sheet 1 and a back electrode 3, wherein the size areas of the front electrode 2 and the back electrode 3 are consistent with the cross-sectional area of the PTC sheet 1; the main material of the front electrode 2 and the back electrode 3 is any one of copper, nickel or copper-nickel alloy; the PTC sheet 1 is an isotropic material and has a positive temperature coefficient thermistor property in the thickness direction, width direction and length direction of the PTC sheet.
And step S3, filling the gaps between the side edges of the PTC elements and the hollow frame 4 with insulating materials 5, and removing the temporary bonding materials at the bottom after the insulating materials 5 are cured to obtain the frame material.
In this embodiment, the hollow frame 4 and the PTC element need to be analyzed and filled with an insulating material 5, which may be a liquid material or a sheet material; the gap can be filled with the insulating material 5 by point coating, spraying or compression molding of a mold for the liquid insulating material, and the insulating material 5 for the tensile material can be pressed into the gap by pressing; wherein the insulating material only fills the gap and does not form a material residue on the surface of the PTC element.
After the insulating material is filled, high-temperature curing is performed on the insulating material to ensure the bonding force between the insulating material 5 and the PTC element and the hollow frame 4.
In the embodiment, the temporary bonding material is mainly removed in a physical mode, and the front electrode 2 and the back electrode 3 of the PTC element are exposed after the temporary bonding material is removed, so that subsequent products can be conveniently processed.
Step S4: through holes perpendicular to the plane of the PTC elements are machined in the insulating material on the sides of the frame material.
Step S5: and forming continuous conductive layers and metal through holes 7 on the upper and lower surfaces of the frame material and the inner side walls of the through holes in a copper deposition and electroplating mode.
In the embodiment, the copper deposition and electroplating manner to form the conductive layer means that metal is deposited on the surfaces of the insulating material and the conductive material in an undifferentiated manner, and the conductive metal is further thickened in an electroplating manner to ensure the conductive and heat dissipation capabilities; the metal deposition mode can be formed by sputtering, evaporation or chemical plating; the conductive metal is generally a metal with good heat dissipation, such as copper, and the thickness of the conductive metal is usually designed according to the heat dissipation requirement and is generally controlled to be 15-100 micrometers.
Step S6: the conductive layer is processed by pattern line transfer, and the processing of the back electrode lead-out pad 9, the front electrode lead-out pad 8, and the conductive line 6 is completed.
The pattern circuit transfer mode specifically means that a layer of temporary protection material is covered on the surface of the whole conductive layer;
according to the design of the pattern circuit, removing part of the temporary protective material in an exposure and development mode, wherein the part covered by the protective material is a conductive part required by design, and the part covered by the protective material is removed to be an unnecessary conductive part;
removing the metal layer of the unnecessary conductive part by adopting a chemical liquid corrosion mode;
the temporary protective material is removed by chemical liquid, and the processing of the conductive circuit 6 can be completed.
Step S7: and covering the insulating material 5 on the surface of the material except the front electrode lead-out plate and the back electrode lead-out plate to finish the processing of the PTC device.
In this embodiment, the insulating material 5 is covered on the upper surface of the conductive circuit and the hollow frame 4 and between the front electrode lead-out plate 8 and the back electrode lead-out plate 9; the thicknesses of the conductive circuit 6 and the insulating material 5 covering the upper surface of the hollow frame 4 are correspondingly designed according to the overall thickness of the PTC device, and can be controlled to be 15-300 mu m generally; the thickness of the insulating material 5 between the front electrode lead-out plate 8 and the back electrode lead-out plate 9 and the height difference after the electrode lead-out are controlled between 0 and 20 mu m.
The utility model discloses still provide another kind of PTC device's manufacturing method, include:
step S1: and providing an insulating plate, forming a hollow area on the insulating plate, and finishing the processing of the hollow frame 4.
In this embodiment, the insulation board is a cured thermosetting resin, which is FR4 or BT material containing glass fiber, the thickness of the insulation board is greater than or equal to that of the PTC element, and the height difference is optimally controlled to be 0-20 μm to ensure the subsequent processing effect.
The hollow area is formed on the insulating board, the forming mode can be mainly any mode of drilling, notching or groove milling, the size of the hollow area needs to be larger than that of the PTC element, the design can be carried out by combining the actual PTC device size and the PTC element placement deviation, and the difference between the size of the hollow area and the size of the PTC element needs to be controlled to be 0.06-0.1mm under the normal condition so as to ensure the maximization of the performance.
Step S2: and placing the PTC element in the hollow area of the hollow frame, and sealing the bottom of the hollow frame by using a temporary bonding material to support the PTC element.
In the embodiment, the temporary bonding glue is adopted at the bottom of the frame for sealing, so that the normal placement of the PTC element is ensured, and the PTC element is fixed; the temporary bonding material can wholly seal the insulating plate, and can also only seal the hollow position of the insulating plate; a generally common temporary bonding material may be a pyrolytically or mechanically removable material.
The PTC element in the embodiment is composed of a front electrode 2, a PTC sheet 1 and a back electrode 3, wherein the size areas of the front electrode 2 and the back electrode 3 are consistent with the cross-sectional area of the PTC sheet 1; the main material of the front electrode 2 and the back electrode 3 is any one of copper, nickel or copper-nickel alloy; the PTC sheet 1 is an isotropic material and has a positive temperature coefficient thermistor property in the thickness direction, width direction and length direction of the PTC sheet.
And step S3, filling the gaps between the side edges of the PTC elements and the hollow frame 4 with insulating materials 5, and removing the temporary bonding materials at the bottom after the insulating materials 5 are cured to obtain the frame material.
In this embodiment, the hollow frame 4 and the PTC element need to be analyzed and filled with an insulating material 5, which may be a liquid material or a sheet material; the gap can be filled with the insulating material 5 by point coating, spraying or compression molding of a mold for the liquid insulating material, and the insulating material 5 for the tensile material can be pressed into the gap by pressing; wherein the insulating material only fills the gap, and no material residue is formed on the surface of the PTC element.
After the insulating material is filled, high-temperature curing is performed on the insulating material to ensure the bonding force between the insulating material 5 and the PTC element and the hollow frame 4.
In the embodiment, the temporary bonding material is mainly removed in a physical mode, and the front electrode 2 and the back electrode 3 of the PTC element are exposed after the temporary bonding material is removed, so that subsequent products can be conveniently processed.
Step S4: and forming continuous conductive layers on the upper and lower surfaces of the obtained frame material by copper deposition and electroplating.
In the embodiment, the copper deposition and electroplating manner to form the conductive layer means that metal is deposited on the surfaces of the insulating material and the conductive material in an undifferentiated manner, and the conductive metal is further thickened in an electroplating manner to ensure the conductive and heat dissipation capabilities; the metal deposition mode can be formed by sputtering, evaporation or chemical plating; the conductive metal is generally a metal with good heat dissipation, such as copper, and the thickness of the conductive metal is usually designed according to the heat dissipation requirement and is generally controlled to be 15-100 micrometers.
Step S5: the conductive layer is processed in a pattern circuit mode, and the PTC element front electrode 2 and the PTC element back electrode 3 are led out through the conductive circuit 6.
The conductive traces 6 need to be in direct contact with both the front electrode 2 and the back electrode 3 of the PTC element, and the contact area is not particularly limited.
Step S6: the front electrode lead-out plate 8 and the back electrode lead-out plate 9 are processed by dipping silver paste and electroplating tin aiming at the device.
The front electrode lead-out disc 8 and the back electrode lead-out disc are directly covered with the conductive circuit 6, so that the front electrode 2 of the PTC element is transferred to the front electrode lead-out disc 8 through the conductive circuit 6, and the back electrode 3 of the PTC element is transferred to the back electrode lead-out disc 9 through the conductive circuit 6.
Step S7: and covering the insulating material 5 on the surface of the material except the front electrode lead-out plate and the back electrode lead-out plate to finish the processing of the PTC device.
To sum up, adopt the utility model discloses a technical scheme has following beneficial effect:
the utility model provides a solve the packaging structure of current PTC device when processing and making drilling because of material toughness leads to drilling efficiency low, with high costs greatly, have during the cutting burr to the time back end use unusual and single device four sides to reveal the PTC material and lead to its problem that has the reliability risk easily. This scheme of adoption has following advantage:
the PTC material does not need to be drilled, so that the processing efficiency of the PTC device can be greatly improved;
the PTC material wraps the black insulating material and the insulating frame all around, so the PTC material can greatly improve the reliability because of the protection of the insulating material, and meanwhile, because the side wall has a protective material, no wire drawing field exists when cutting is carried out, the edge of the device is more neat, and the use of subsequent products is facilitated.
The above-described embodiments do not limit the scope of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the above-described embodiments should be included in the protection scope of the technical solution.
Claims (6)
1. A packaging structure of a PTC device is characterized in that: comprises a PTC element, wherein the PTC element comprises a front electrode, a PTC sheet and a back electrode which are sequentially stacked; a hollow frame is surrounded by the side edge of the PTC element, and an insulating material is filled between the hollow frame and a gap of the side edge of the PTC element; the front electrode and the back electrode of the PTC element are respectively connected with the front electrode lead-out disc and the back electrode lead-out disc; the front electrode lead-out disc and the back electrode lead-out disc extend to the same surface of the packaging structure or are independently distributed on the side edge of the packaging structure.
2. The package structure of claim 1, wherein: the connection modes between the front electrode of the PTC element and the front electrode lead-out disc and between the back electrode of the PTC element and the back electrode lead-out disc comprise direct contact connection, conductive circuit connection and conductive circuit + metal via hole connection.
3. The package structure of claim 1, wherein: the front electrode lead-out disc and the back electrode lead-out disc are located on the same plane of the packaging structure, the back electrode is in direct contact connection with the back electrode lead-out disc, and the front electrode of the PTC element is in connection with the front electrode lead-out disc through a conductive circuit and a metal via hole.
4. The package structure of claim 1, wherein: the front electrode lead-out disc and the back electrode lead-out disc are independently distributed on the side face of the packaging structure, and the front electrode lead-out disc and the back electrode lead-out disc are connected through conductive circuits.
5. The package structure of claim 1, wherein: the packaging structure is characterized in that the area of the packaging structure except the front electrode lead-out disc and the back electrode lead-out disc is covered with an insulating material.
6. The package structure of claim 1, wherein: the hollow frame is made of cured thermosetting resin materials.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020234856.6U CN211150217U (en) | 2020-03-02 | 2020-03-02 | Packaging structure of PTC device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020234856.6U CN211150217U (en) | 2020-03-02 | 2020-03-02 | Packaging structure of PTC device |
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| Publication Number | Publication Date |
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| CN211150217U true CN211150217U (en) | 2020-07-31 |
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| CN202020234856.6U Active CN211150217U (en) | 2020-03-02 | 2020-03-02 | Packaging structure of PTC device |
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| CN (1) | CN211150217U (en) |
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