Chip heater and its manufacturing process

Abstract

The present invention discloses a chip heater and its manufacturing process, including a carrier layer, a heating layer and a copper foil welding layer, the carrier layer has a plurality of carrier substrates arranged in sequence, each carrier substrate is composed of a high temperature resistant glass fiber cloth and a colloid layer positioned on the front of the high temperature resistant glass fiber cloth; the heating layer is positioned on the front of the carrier layer, the copper foil welding layer is positioned on the back of the carrier layer, and the heating layer is also connected with the copper foil welding layer; a heating layer pattern is etched on the front of the heating layer, a welding layer pattern is etched on the back of the copper foil welding layer, and a photosensitive epoxy resin packaging layer is respectively encapsulated in the middle of the heating layer pattern and the middle of the welding layer pattern, and a tin-plated layer is electroplated on the remaining parts of the heating layer pattern and the welding layer pattern. The chip heater prepared by the present invention is not only novel and reasonable in structure, but also has low power consumption, high resistance value accuracy, high power stability, is not easily damaged by external forces, and has a long product service life.

Description

Technical Field

[0001] The invention relates to the technical field of heaters, and in particular provides a sheet heater and a manufacturing process thereof. Background Art

[0002] At present, the most common heater on the market is the bridge wire heater, and its working principle is: the current output by the external power supply is applied to the resistance bridge wire of the heater through the metal foot wire, the current heats the bridge wire, and the heated bridge wire can supply heat to the outside world.

[0003] However, the above-mentioned bridge wire heater not only has high power consumption and low precision, but is also easily damaged by external forces.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] In order to overcome the above-mentioned defects, the present invention provides a chip heater and a manufacturing process thereof. The manufacturing process is simple and reliable, and the chip heater manufactured by the manufacturing process has the characteristics of novel and reasonable structure, low power consumption, high resistance value accuracy, high power stability, not easily damaged by external force, and long product service life.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a sheet-type heater, comprising a carrier layer, a heating layer and a copper foil welding layer, wherein the carrier layer has a plurality of carrier substrates stacked in sequence, and each of the carrier substrates is composed of a high-temperature resistant glass fiber cloth and a colloid layer positioned on the front side of the high-temperature resistant glass fiber cloth; the heating layer is positioned on the front side of the carrier layer, the copper foil welding layer is positioned on the back side of the carrier layer, and the heating layer is also conductively connected to the copper foil welding layer;

[0007] In addition, a heating layer pattern is etched on the front side of the heating layer, and a soldering layer pattern is etched on the back side of the copper foil soldering layer. A photosensitive epoxy resin encapsulation layer is respectively encapsulated in the middle of the heating layer pattern and the middle of the soldering layer pattern, and a tin-plated layer is respectively electroplated on the remaining part of the heating layer pattern and the remaining part of the soldering layer pattern.

[0008] As a further improvement of the present invention, the thickness of the high temperature resistant glass fiber cloth is 50 to 170 μm, the thickness of the colloid layer is 60 to 180 μm, and the overall thickness of the carrier layer is 360 to 600 μm;

[0009] In addition, in the carrier layer, the high temperature resistant glass fiber cloth of one of the carrier substrates located at the top is arranged on the colloid layer of another of the carrier substrates located at the bottom.

[0010] As a further improvement of the present invention, the thickness of the heating layer is 3 to 10 μm, and the thickness of the copper foil welding layer is 30 to 120 μm;

[0011] The structure for achieving electrical connection between the heating layer and the copper foil welding layer is as follows: the carrier layer, the heating layer and the copper foil welding layer connected together are collectively referred to as a foil substrate, a through hole that can penetrate the carrier layer and the heating layer is opened on the foil substrate, and a copper layer is plated in the through hole, and the heating layer is electrically connected to the copper foil welding layer through the copper layer.

[0012] As a further improvement of the present invention, the thickness of the photosensitive epoxy resin packaging layer is 10 to 30 μm; the thickness of the tin-plated layer is 3 to 30 μm.

[0013] As a further improvement of the present invention, a heat storage layer made of copper is sandwiched between the two carrier substrates.

[0014] The present invention also provides a manufacturing process of the sheet-type heater, which is carried out according to the following steps:

[0015] a. Cut out a piece of high temperature resistant glass fiber cloth according to the design, wherein the high temperature resistant glass fiber cloth has a front side and a back side, apply a layer of polyimide modified epoxy resin on the front side of the high temperature resistant glass fiber cloth, and dry and age the polyimide modified epoxy resin to form a colloid layer with a solid content greater than 99%; wherein the high temperature resistant glass fiber cloth and the colloid layer connected together are collectively referred to as a carrier matrix;

[0016] b. Stacking a plurality of the carrier substrates in sequence and performing a pressing process to obtain a carrier layer; firstly stacking a heating layer on the front side of the carrier layer, and stacking a copper foil welding layer on the back side of the carrier layer, and then performing a high-temperature pressing process to obtain a foil-coated substrate;

[0017] c. Performing through-hole processing on the foil substrate according to design requirements and metallizing the through-holes to achieve conduction between the heating layer and the copper foil welding layer;

[0018] d. etching a heating layer pattern on the front side of the heating layer, and etching a welding layer pattern on the back side of the copper foil welding layer;

[0019] e. respectively encapsulating a layer of photosensitive epoxy resin encapsulation layer in the middle of the heating layer pattern and the middle of the welding layer pattern to obtain a semi-finished heater;

[0020] f. Cut the semi-finished heater into a plurality of sheets, and then electroplate a tin layer on the remaining portion of the heating layer pattern and the remaining portion of the welding layer pattern on each sheet to obtain a finished sheet heater.

[0021] As a further improvement of the present invention, in the above step a, the thickness of the high temperature resistant glass fiber cloth is 50 to 170 μm. After a layer of polyimide-modified epoxy resin is scraped on the front side of the high temperature resistant glass fiber cloth, the high temperature resistant glass fiber cloth together with the polyimide-modified epoxy resin thereon is placed in an infrared oven and dried for 4 hours under environmental conditions of a temperature of 120°C and a vacuum degree of <-60KP. Then, the dried high temperature resistant glass fiber cloth and the polyimide-modified epoxy resin are placed in a constant temperature oven together and aged for 96 hours under a constant temperature of 40°C. At this time, a colloidal layer with a solid content greater than 99% and a thickness of 60 to 180 μm is formed; at that time, the high temperature resistant glass fiber cloth and the colloidal layer connected together constitute the carrier matrix.

[0022] As a further improvement of the present invention, in the above step b, the overall thickness of the carrier layer is 360-600 μm, and the high temperature resistant glass fiber cloth of one of the carrier substrates located above in the carrier layer is arranged on the colloid layer of another of the carrier substrates located below;

[0023] In addition, in the above step b, the thickness of the heating layer is 3-10 μm, and the thickness of the copper foil welding layer is 30-120 μm; and the specific process parameters of the high-temperature pressing treatment of the stacked carrier layer, the heating layer and the copper foil welding layer are: pressing temperature 200-250°C, pressing force 30-50 Kg / cm 2 , pressing time 5 to 10 hours.

[0024] As a further improvement of the present invention, a heat storage layer made of copper is sandwiched between the two carrier substrates.

[0025] As a further improvement of the present invention, in the above step c, a through hole that can penetrate the carrier layer and the heating layer is drilled on the foil substrate according to design requirements, and a copper layer is plated in the through hole, and the heating layer is connected to the copper foil welding layer through the copper layer;

[0026] In the above step e, the thickness of the photosensitive epoxy resin encapsulation layer is 10 to 30 μm;

[0027] In the above step f, the size of the flakes is: length 1.8-2.4 mm, width 1-1.5 mm; the thickness of the tin-plated layer is 3-30 μm.

[0028] The beneficial effects of the present invention are as follows: the present invention has produced a new type of chip heater through structural innovation and manufacturing process innovation. The chip heater is not only novel and reasonable in structure, but also has low power consumption (the power of the matching external power supply is also small), high resistance accuracy, high power stability, is not easily damaged by external forces, and has a long product service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of the front side of the pellet obtained after the cutting process in step f of the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the back side of the pellet obtained after the cutting process in step f of the present invention;

[0031] Figure 3 It is a schematic diagram of the cross-sectional structure of the sheet heater of the present invention.

[0032] Combined with the accompanying drawings, the following description is given:

[0033] 1——Carrier layer 10——High temperature resistant glass fiber cloth

[0034] 11——Colloid layer 2——Heating layer

[0035] 3——Copper foil welding layer 4——Photosensitive epoxy resin encapsulation layer

[0036] 5——Tin plating layer 6——Copper plating layer

[0037] 7 - Heat storage layer DETAILED DESCRIPTION

[0038] The following describes the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0039] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the art, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportion or adjustment of size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0040] Embodiment 1:

[0041] Please see attached Figure 3As shown, it is a schematic diagram of the cross-sectional structure of the sheet heater of the present invention. The sheet heater comprises a carrier layer 1, a heating layer 2 and a copper foil welding layer 3, wherein the carrier layer 1 has a plurality of carrier substrates arranged in sequence, and each of the carrier substrates is composed of a high temperature resistant glass fiber cloth 10 and a colloid layer 11 positioned on the front of the high temperature resistant glass fiber cloth 10; the heating layer 2 is positioned on the front of the carrier layer 1, and the copper foil welding layer 3 is positioned on the back of the carrier layer 1, and the heating layer 2 is also connected to the copper foil welding layer 3; in addition, a heating layer pattern is etched on the front of the heating layer 2, and a welding layer pattern is etched on the back of the copper foil welding layer 3, and a photosensitive epoxy resin encapsulation layer 4 is respectively encapsulated in the middle of the heating layer pattern and the middle of the welding layer pattern, and a tin plating layer 5 is respectively electroplated on the remaining part of the heating layer pattern and the remaining part of the welding layer pattern.

[0042] In this embodiment, preferably, the thickness of the high temperature resistant glass fiber cloth 10 is 50-170 μm, the thickness of the colloid layer 11 is 60-180 μm, and the overall thickness of the carrier layer 1 is 360-600 μm;

[0043] In addition, in the carrier layer 1 , the high temperature resistant glass fiber cloth 10 of one of the carrier substrates located at the upper side is arranged on the colloid layer 11 of the other of the carrier substrates located at the lower side.

[0044] In this embodiment, preferably, the thickness of the heating layer 2 is 3-10 μm, and the thickness of the copper foil welding layer 3 is 30-120 μm. In the actual production process, the thickness of the heating layer 2 and the copper foil welding layer 3 will be adjusted according to the heating power.

[0045] The structure for achieving electrical connection between the heating layer 2 and the copper foil welding layer 3 is as follows: the carrier layer 1, the heating layer 2 and the copper foil welding layer 3 connected together are collectively referred to as a foil substrate, a through hole that can penetrate the carrier layer 1 and the heating layer 2 is opened on the foil substrate, and a copper layer 6 is plated in the through hole, and the heating layer 2 is electrically connected to the copper foil welding layer 3 through the copper layer 6.

[0046] In this embodiment, preferably, the thickness of the photosensitive epoxy resin packaging layer 4 is 10-30 μm; the thickness of the tin-plated layer 5 is 3-30 μm.

[0047] In this embodiment, preferably, a heat storage layer 7 made of copper is sandwiched between the two carrier substrates.

[0048] The manufacturing process of the sheet-type heater of the present invention is described in detail below.

[0049] Preparation Example 1:

[0050] The manufacturing process of the sheet heater is carried out according to the following steps:

[0051] a. Cut out a piece of high temperature resistant glass fiber cloth 10 according to the design, wherein the high temperature resistant glass fiber cloth 10 has a front side and a back side, apply a layer of polyimide modified epoxy resin on the front side of the high temperature resistant glass fiber cloth 10, and dry and age the polyimide modified epoxy resin to form a colloid layer 11 with a solid content greater than 99%; wherein the high temperature resistant glass fiber cloth 10 and the colloid layer 11 connected together are collectively referred to as a carrier matrix;

[0052] b. Stacking a plurality of the carrier substrates in sequence and subjecting them to pressing treatment to obtain a carrier layer 1, that is, after the pressing treatment, the colloid layer 11 of another carrier substrate located below will penetrate into the gap of the high-temperature resistant glass fiber cloth 10 of the carrier substrate located above, so that the plurality of carrier substrates are integrated; firstly stacking a heating layer 2 on the front side of the carrier layer 1, and stacking a copper foil welding layer 3 on the back side of the carrier layer 1, and then subjecting them to high-temperature pressing treatment to obtain a foil-coated substrate;

[0053] c. Performing through-hole processing on the foil substrate according to design requirements and metallizing the through-holes to achieve conduction between the heating layer 2 and the copper foil welding layer 3;

[0054] d. Etching a heating layer pattern on the front side of the heating layer 2 by chemical etching, and etching a welding layer pattern on the back side of the copper foil welding layer 3 by chemical etching; wherein the pattern accuracy is controlled within ±50 μm;

[0055] e. A layer of photosensitive epoxy resin encapsulation layer 4 is respectively encapsulated on the middle part of the heating layer pattern and the middle part of the welding layer pattern to obtain a semi-finished heater; wherein the photosensitive epoxy resin encapsulation layer on the heating layer pattern is made of green photosensitive epoxy resin, and the photosensitive epoxy resin encapsulation layer on the welding layer pattern is made of white photosensitive epoxy resin;

[0056] f. Cut the semi-finished product of the heater into several pieces (the front and back structures of the pieces can be found in the attached Figure 1 and attached Figure 2 As shown), a tin-plated layer 5 is then electroplated on the remaining portion of the heating layer pattern and the remaining portion of the welding layer pattern on each of the chips to obtain a finished chip heater.

[0057] In this preparation example, preferably, in the above step a, the thickness of the high temperature resistant glass fiber cloth 10 is 50-170 μm, the length is 650 mm, and the width is 550 mm. After a layer of polyimide-modified epoxy resin is scraped on the front side of the high temperature resistant glass fiber cloth 10, the high temperature resistant glass fiber cloth 10 and the polyimide-modified epoxy resin thereon are placed in an infrared oven together, and dried for 4 hours under environmental conditions of a temperature of 120°C and a vacuum degree of <-60KP, and then the dried high temperature resistant glass fiber cloth 10 and the polyimide-modified epoxy resin are placed in a constant temperature oven together, and aged for 96 hours under a constant temperature of 40°C, at which time a colloidal layer 11 with a solid content greater than 99% and a thickness of 60-180 μm is formed; at that time, the high temperature resistant glass fiber cloth 10 and the colloidal layer 11 connected together constitute the carrier matrix.

[0058] In this preparation example, preferably, in the above step b, the overall thickness of the carrier layer 1 is 360-600 μm, and the high temperature resistant glass fiber cloth 10 of one of the carrier substrates located above in the carrier layer 1 is arranged on the colloid layer 11 of another of the carrier substrates located below;

[0059] In addition, in the above step b, the thickness of the heating layer 2 is 3-10 μm, and the thickness of the copper foil welding layer 3 is 30-120 μm; and the specific process parameters for high-temperature pressing of the stacked carrier layer 1, the heating layer 2 and the copper foil welding layer 3 are: pressing temperature 200-250°C (preferably 220°C), pressing force 30-50 Kg / cm 2 (It may be further preferred to be 40Kg / cm 2 ), pressing time 5 to 10 hours.

[0060] In this preparation example, it is further preferred that a heat storage layer 7 made of copper is sandwiched between the two carrier substrates.

[0061] In this preparation example, preferably, in the above step c, a through hole that can penetrate the carrier layer 1 and the heating layer 2 is drilled on the foil substrate according to the design requirements, and a copper-plated layer 6 is plated in the through hole, and the heating layer 2 is connected to the copper foil welding layer 3 through the copper-plated layer 6;

[0062] In the above step e, the thickness of the photosensitive epoxy resin encapsulation layer 4 is 10 to 30 μm;

[0063] In the above step f, the size of the pellets is: length 1.8-2.4 mm, width 1-1.5 mm; the thickness of the tin-plated layer 5 is 3-30 μm.

[0064] In summary, the present invention has produced a new type of chip heater through structural innovation and manufacturing process innovation. The chip heater is not only novel and reasonable in structure, but also has low power consumption (the power of the matching external power supply is also small), high resistance accuracy, high power stability, is not easily damaged by external forces, and has a long product service life.

[0065] The above description is only a preferred embodiment of the present invention, but is not intended to limit the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A process for manufacturing a sheet heater, characterized in that: The process is carried out in the following steps: a. cutting out a piece of high temperature resistant glass fiber cloth (10) according to the design, wherein the high temperature resistant glass fiber cloth (10) has a front side and a back side, applying a layer of polyimide modified epoxy resin on the front side of the high temperature resistant glass fiber cloth (10), and drying and aging the polyimide modified epoxy resin to form a colloid layer (11) with a solid content greater than 99%; wherein the high temperature resistant glass fiber cloth (10) and the colloid layer (11) connected together are collectively referred to as a carrier matrix; b. stacking a plurality of the carrier matrices in sequence, and pressing them to obtain a carrier layer (1); firstly stacking a heating layer (2) on the front side of the carrier layer (1), and stacking a copper foil welding layer (3) on the back side of the carrier layer (1), and then stacking the heating layer (2) on the front side of the carrier layer (1). After placing, high-temperature pressing treatment is performed to obtain a foil substrate; c. through-hole processing is performed on the foil substrate according to design requirements, and the through-holes are metallized to achieve conduction between the heating layer (2) and the copper foil welding layer (3); d. a heating layer pattern is etched on the front of the heating layer (2), and a welding layer pattern is etched on the back of the copper foil welding layer (3); e. a photosensitive epoxy resin encapsulation layer (4) is respectively encapsulated in the middle of the heating layer pattern and the middle of the welding layer pattern to obtain a semi-finished heater; the semi-finished heater is cut into a plurality of chips, and then a tin-plated layer (5) is respectively electroplated on the remaining part of the heating layer pattern and the remaining part of the welding layer pattern on each chip to obtain a finished chip heater.

2. The manufacturing process of the sheet heater according to claim 1, characterized in that: In the above step a, the thickness of the high temperature resistant glass fiber cloth (10) is 50 to 170 μm. After a layer of polyimide-modified epoxy resin is scraped on the front side of the high temperature resistant glass fiber cloth (10), the high temperature resistant glass fiber cloth (10) together with the polyimide-modified epoxy resin thereon is placed in an infrared oven and dried for 4 hours under environmental conditions of a temperature of 120° C. and a vacuum degree of less than -60KP. Then, the dried high temperature resistant glass fiber cloth (10) and the polyimide-modified epoxy resin are placed in a constant temperature oven and aged for 96 hours under a constant temperature of 40° C., at which time a colloid layer (11) with a solid content greater than 99% and a thickness of 60 to 180 μm is formed; at this time, the high temperature resistant glass fiber cloth (10) and the colloid layer (11) connected together constitute the carrier matrix.

3. The manufacturing process of the sheet heater according to claim 1, characterized in that: In the above step b, the overall thickness of the carrier layer (1) is 360-600 μm, and the high-temperature resistant glass fiber cloth (10) of one of the carrier substrates located above the carrier layer (1) is arranged on the colloidal layer (11) of another of the carrier substrates located below; in addition, in the above step b, the thickness of the heating layer (2) is 3-10 μm, and the thickness of the copper foil welding layer (3) is 30-120 μm; and the specific process parameters for high-temperature pressing treatment of the stacked carrier layer (1), the heating layer (2) and the copper foil welding layer (3) are: pressing temperature 200-250°C, pressing force 30-50 Kg / cm2, pressing time 5-10 hours.

4. The manufacturing process of the sheet heater according to claim 3, characterized in that: A heat storage layer (7) made of copper is sandwiched between the two carrier substrates.

5. The manufacturing process of the sheet heater according to claim 1, characterized in that: In the above step c, a through hole that can penetrate the carrier layer (1) and the heating layer (2) is drilled on the foil substrate according to design requirements, and a copper-plated layer (6) is plated in the through hole, and the heating layer (2) is connected to the copper foil welding layer (3) through the copper-plated layer (6); in the above step e, the thickness of the photosensitive epoxy resin encapsulation layer (4) is 10 to 30 μm; in the above step f, the size of the pellets is: length 1.8 to 2.4 mm, width 1 to 1.5 mm; the thickness of the tin-plated layer (5) is 3 to 30 μm.

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