CN102412336A - Miniaturized infrared thermal sensing module and method of manufacturing the same - Google Patents

Abstract

A method for manufacturing a miniaturized infrared thermal sensing component, the steps of which include: providing a wafer and a substrate, wherein the wafer is provided with a plurality of chips. Forming four pads, a thermistor, and an infrared thermal sensing layer at the bottom of the chip, wherein the four pads are electrically connected to the thermistor and the infrared thermal sensing layer, respectively. Fixing a plurality of solders on the pads, respectively. Back-etching the top surface of the chip to form a sensing film and a ring side wall surrounding the sensing film. Butt-joining the wafer and the substrate. Heating the solder to weld each chip to the substrate. Inserting a plurality of filters into the ring side wall of each chip, respectively. Cutting the wafer and the substrate to form a plurality of infrared thermal sensing components. In addition, the present invention further provides a miniaturized infrared thermal sensing component.

Description

Miniaturized infrared thermal sensing component and manufacturing method thereof

technical field

The invention relates to a miniaturized infrared thermal sensing component, especially a thermal sensing component for receiving infrared rays and a manufacturing method thereof.

Background technique

Please refer to Fig. 1 to Fig. 2, this is the conventional infrared thermal sensing assembly, which includes: a base 1a, several pins 2a, a chip 3a, several wires 4a, a cover 5a, a light filter Sheet 6a and a thermistor 7a.

The base 1a forms several through holes 11a through the base 1a, and the pins 2a are respectively disposed in the through holes 11a; the chip 3a has a sensing film 31a and a ring side wall 32a surrounding the sensing film 31a, An opening 321a is formed on the bottom surface of the ring side wall 32a, and the bottom surface of the ring side wall 32a is fixed on the base 1a, the thermistor 7a is arranged on the base 1a, and the wires 4a respectively connect the pins 2a to the ring Side wall 32a top surface and thermistor 7a; The cover body 5a is fixed on the base 1a and the chip 3a is arranged in the cover body 5a, and the position of the cover body 5a corresponding to the sensing film 31a forms a fixing hole 51a, the filter The optical sheet 6a is fixed on the fixing hole 51a.

The forming of the above-mentioned structure mainly prepares a wafer (figure omitted) earlier, and this wafer has several wafers 3a, and before these wafers 3a are assembled, it all carries out back etching earlier, in order to form in each wafer 3a A groove-like structure.

Then, the wafer is cut to form several chips 3a, and one of the chips 3a is taken, and the chip 3a is bonded to the base 1a with the pins 2a by a die bonder (not shown), and the heat-sensitive The resistor 7a is set on the base 1a, and then the chip 3a and the thermistor 7a are respectively connected to the pins 2a with a wire bonder (not shown), and finally, the cover 5a with the optical filter 6a is tightly sealed. fit on the base 1a. Wherein, the pin 2a is installed in the base 1a and the optical filter 6a is fixed on the cover 5a, these two parts must be prepared before the above assembly.

The conventional infrared thermal sensing components are mainly received by the infrared sensing film 31a through the infrared transmission filter 6a. However, the distance between the optical filter 6a and the sensing film 31a is too large, so overlapping interference phenomenon of target infrared radiation is likely to occur. Furthermore, a single infrared thermal sensing component must be produced as a unit during production, and the pin 2a is installed in the base 1a, the filter 6a is fixed on the cover 5a, and the thermistor 7a needs to be glued. Connected to the base 1a and wired to the pin 2a, these three parts require additional manufacturing processes, which makes the overall production cost too high.

Therefore, the inventor of the present invention feels that the above shortcomings can be improved, so he devoted himself to research and combined with the application of theories, and finally proposed an invention with reasonable design and effective improvement of the above shortcomings.

Contents of the invention

The main object of the present invention is to provide an infrared heat sensing component with small size, low production cost and avoiding infrared overlapping interference phenomenon.

In order to achieve the above-mentioned purpose, the present invention provides a method for manufacturing a miniaturized infrared thermal sensing component. The steps include: providing a wafer and a substrate, the wafer is provided with several chips; forming four chips at the bottom of each chip Two pads, a thermistor and an infrared thermal sensing layer, two of the four pads are electrically connected to the thermistor, and the other two pads are electrically connected to the infrared thermal sensor A plurality of solders are respectively fixed on the four soldering pads; the top surface of each chip is etched backward, so that a sensing film is formed in each chip and a sensor is connected around the sensing film. a ring side wall; several solders are respectively fixed on the at least two welding pads and the thermistor; the wafer is connected to the substrate; the solders are heated to weld each chip to the substrate; Several optical filters are respectively inserted in the ring side wall of each wafer; and the wafer and the substrate are cut to form several infrared thermal sensing components.

The present invention also provides a method for manufacturing a miniaturized infrared thermal sensing component, the steps of which include: providing a wafer and a substrate, the wafer is provided with several chips; forming four pads at the bottom of each chip, A thermistor and an infrared heat sensing layer, two of the four pads are electrically connected to the thermistor, and the other two pads are electrically connected to the infrared heat sensing layer; A solder is respectively fixed on the four welding pads; the top surface of each chip is etched backward, so that a sensing film is formed in each chip and a ring side wall is connected around the sensing film; cutting the wafer into several chips; fixing several solders on the at least two pads and the thermistor respectively; bonding each chip to the substrate; heating the solders to weld each chip to the substrate together; inserting several optical filters in the ring side wall of each wafer; and cutting the substrate to form several infrared thermal sensing components.

The present invention also provides a miniaturized infrared heat sensing component, including: a chip, which has a sensing film and a ring side wall surrounding and connected to the sensing film, and an infrared heat sensor is formed in the sensing film. In the sensing layer, an opening is formed on the top surface of the side wall of the ring, four pads and a thermistor are formed on the bottom of the side wall of the ring; and an optical filter is arranged on the inner edge of the side wall of the ring through the opening ; Among them, two of the four pads are electrically connected to the thermistor, and the other two pads are electrically connected to the infrared thermal sensing layer.

The present invention has following beneficial effect:

(1) Mass production is possible to reduce production cost: the manufacturing method of the present invention can be mass-produced on a large scale without the need for individual production, therefore, the production cost can be greatly reduced.

(2) Avoid overlapping interference of infrared rays: the present invention arranges the optical filter on the inner edge of the ring side wall, so that the distance between the optical filter and the sensing film is greatly shortened, thereby effectively avoiding overlapping interference of infrared rays Phenomenon.

(3) Significantly reduced size: In the present invention, a part of the optical filter is arranged in the space covered by the inner edge of the ring side wall, so that the height of the infrared thermal sensing component is greatly reduced, thereby reducing the size. Also, the use of circuit boards further reduces the size.

(4) Reduce raw material cost: the present invention does not need to use a cover body, and the thermistor is directly formed on the bottom of the ring side wall, therefore, the raw material cost required for each infrared heat sensing component will be significantly reduced.

(5) Wide range of applications: the overall size of the present invention is equivalent to the size of a chip, therefore, the miniaturized infrared heat sensing component of the present invention has a wider range of applications, such as being applicable to mobile phones, ear thermometers and sensors, etc. devices, and enable these devices to have a reduced size space.

In order to enable a further understanding of the features and technical contents of the present invention, please refer to the following detailed descriptions and drawings of the present invention, but these descriptions and drawings are only used to illustrate the present invention, rather than to limit the scope of rights of the present invention. any restrictions.

Description of drawings

FIG. 1 is a schematic diagram of a conventional infrared sensing device.

FIG. 2 is a cross-sectional view of a conventional infrared sensing component.

FIG. 3 is a flowchart of the steps of the first embodiment of the present invention.

FIG. 4 is a flowchart of the steps of the second embodiment of the present invention.

Fig. 5 is a top view of a third embodiment of the present invention.

Fig. 6 is a bottom view of the third embodiment of the present invention.

7 is a cross-sectional view of a reflective layer coated on a sensing film according to a third embodiment of the present invention.

8 is a cross-sectional view of a reflective layer coated on a circuit board according to a third embodiment of the present invention.

9 is a cross-sectional view of a reflective layer coated on a sensing film according to a fourth embodiment of the present invention.

10 is a cross-sectional view of a reflective layer coated on a circuit board according to a fourth embodiment of the present invention.

Symbol Description

1a base 11a perforation

2a pin 3a chip

31a Sensing film 32a Ring side wall

321a opening 4a wire

5a cover body 51a fixing hole

6a filter 7a thermistor

1 base board 11 circuit board

111 contacts 112 lines

2 chip 21 sensing film

211 infrared heat sensing material 212 opening

22 ring side wall 221 opening

222 inclined plane 223 stepped surface

23 Welding Pads 231 Welding Pads

24 Thermistor 3 Solder

4 The first bonding part 5 Optical filter

6 The second bonding part 7 Reflective layer

Detailed ways

Please refer to FIG. 3 and refer to FIG. 5 to FIG. 10 , which is the first embodiment of the present invention. This embodiment is a method of manufacturing a miniaturized infrared thermal sensing component. The steps include:

A wafer (not shown) and a substrate 1 are provided, the wafer is provided with several chips 2 . Wherein, the substrate 1 can be a circuit board 11 , a ceramic board or a silicon wafer (not shown).

Referring to FIG. 6 , four pads 23 , a thermistor 24 and an infrared thermal sensing layer 211 are formed on the bottom of each chip 2 . The thermistor 24 is formed by a thin film process, and two of the four pads 23 are electrically connected to the thermistor 24 , and the other two pads 23 are electrically connected to the infrared thermal sensing layer 211 . Wherein, each of the four welding pads 23 is formed with at least one welding pad 231 , and the welding pads 23 are formed outside the infrared thermal sensing layer 211 . In addition, the number of pads 23 in this embodiment is four, and the number of pads 231 of each pad 23 is three, but not limited thereto.

Thereafter, several solders 3 (as shown in FIG. 7 ) are respectively fixed on the pads 231 of the pad portion 23 . Wherein, the solders 3 can be fixed on at least one solder pad 231 in each pad portion 23 , or, the solders 3 can be fixed on all the solder pads 231 in each pad portion 23 .

Referring to FIG. 5 , the top surface of each wafer 2 is reversely etched, so that each wafer 2 is formed with a sensing film 21 and a ring side wall 22 surrounding the sensing film 21 . The infrared heat sensing layer 211 is located in the sensing film 21 , and several openings 212 can be formed on the edge of the sensing film 21 (as shown in FIG. 6 ). The inner edges of the ring side walls 22 are all shaped as inclined surfaces (as shown in FIGS. 7 and 8 ) or stepped (as shown in FIGS. 9 and 10 ). Wherein, if the inner edge of the ring side wall 22 is formed into a stepped shape, the top surface of the wafer 2 needs to be etched at least twice.

Referring to FIGS. 6 and 7 , a first adhesive 4 is coated on the substrate 1 . A flip-chip die-bonding machine (not shown) is used to connect the wafer to the substrate 1 in a flip-chip packaging manner. Thereafter, the solder 3 is heated to solder each chip 2 and the substrate 1 together.

Please refer to FIG. 7 , use a die bonder (figure omitted) to insert several optical filters 5 respectively in the ring sidewall 22 of each chip 2, and then coat a first layer on the top surface of each chip 2. Two bonding parts 6.

The wafer and the substrate 1 are diced to form several infrared thermal sensing components.

In addition, the present invention can further coat a reflective layer 7 between the sensing film 21 and the substrate 1 . Wherein, the reflective layer 7 can be coated on the sensing film 21 or the substrate 1 .

Please refer to FIG. 4 and refer to FIG. 5 to FIG. 10, which is the second embodiment of the present invention. This embodiment is a method of manufacturing a miniaturized infrared thermal sensing component, the steps of which include:

A wafer (not shown) and a substrate 1 are provided, and several chips 2 are provided on the wafer. Wherein, the substrate 1 can be a circuit board 11 , a ceramic board or a silicon wafer (not shown).

Referring to FIG. 6 , four pads 23 , a thermistor 24 and an infrared thermal sensing layer 211 are formed on the bottom of each chip 2 . The thermistor 24 is formed by a thin film process, and two of the four pads 23 are electrically connected to the thermistor 24 , and the other two pads 23 are electrically connected to the infrared thermal sensing layer 211 . Wherein, the four welding pads 23 each form at least one welding pad 231, and the welding pads 23 are formed on the outside of the infrared thermal sensing layer 211. In addition, the number of pads 23 in this embodiment is four, and the number of pads 231 of each pad 23 is three, but not limited thereto.

Thereafter, several solders 3 (as shown in FIG. 7 ) are respectively fixed on the pads 231 of the pad portion 23 . Wherein, the solders 3 can be fixed on at least one solder pad 231 in each pad portion 23 , or, the solders 3 can be fixed on all the solder pads 231 in each pad portion 23 .

Referring to FIG. 5 , the top surface of each wafer 2 is reversely etched, so that each wafer 2 is formed with a sensing film 21 and a ring side wall 22 surrounding the sensing film 21 . The infrared heat sensing layer 211 is located in the sensing film 21 , and several openings 212 can be formed on the edge of the sensing film 21 (as shown in FIG. 6 ). The inner edges of the ring side walls 22 are all shaped as inclined surfaces (as shown in FIGS. 7 and 8 ) or stepped (as shown in FIGS. 9 and 10 ). Wherein, if the inner edge of the ring side wall 22 is formed into a stepped shape, the top surface of the wafer 2 needs to be etched at least twice.

Referring to FIGS. 6 and 7 , the wafer is cut into several chips 2 , and a first adhesive 4 is coated on the substrate 1 . Each chip 2 is bonded on the substrate 1 . Thereafter, the solder 3 is heated to solder each chip 2 and the substrate 1 together.

Please refer to FIG. 7 , use a die bonder (figure omitted) and insert several optical filters 5 in the ring sidewall 22 of each chip 2 in a flip-chip packaging manner, and then place them on the ring side wall 22 of each chip 2 A second adhesive member 6 is coated on the top surface.

The substrate 1 is cut to form several infrared thermal sensing components.

In addition, in this embodiment, a reflective layer 7 can be further coated between the sensing film 21 and the substrate 1 .

Please refer to Fig. 5 to Fig. 8, which is the third embodiment of the present invention. This embodiment is a miniaturized infrared heat sensing component manufactured by the above method, which includes: a substrate 1, a chip 2, several Solder 3 , a filter 5 and a reflection layer 7 . The solders 3 connect the substrate 1 and the chip 2 , and the optical filter 5 is inserted in the chip 2 .

Please refer to FIG. 7 , the substrate 1 is a circuit board 11 as an example, but not limited thereto, the substrate 1 can also be a ceramic board or a silicon wafer. Four contact points 111 are formed on the top surface of the circuit board 11 , and the four contact points 111 on the top surface of the circuit board 11 extend downward to form four lines 112 connecting the top surface and the bottom surface of the circuit board 11 . In addition, the numbers of the contacts 111 and the lines 112 are four as an example, but it is not limited thereto.

Please refer to FIG. 5 and FIG. 6 , the chip 2 has a sensing film 21 and a ring side wall 22 surrounding the sensing film 21 . An infrared thermal sensing layer 211 is formed in the sensing film 21, an opening 221 is formed on the top surface of the ring side wall 22, an inclined surface 222 is formed on the inner edge of the ring side wall 22, and four pads are formed on the bottom of the ring side wall 22 23 and a thermistor 24, each of the four pads 23 forms at least one pad 231. The pad portion 23 is formed outside the sensing film 21 . The thermistor 24 is formed between the two pads 23 and is electrically connected to the two pads 23 , while the other two pads 23 are electrically connected to the infrared thermal sensing layer 211 . In addition, several openings 212 may be provided on the outer edge of the sensing film 21 , so that the sensing film 21 is not easy to expand and crack when heated. In addition, here four welding pads 23 are taken as an example, and three welding pads 231 of each welding pad 23 are taken as an example, but it is not limited thereto.

Please refer to FIG. 6 and FIG. 7 , the solder 3 is disposed between the contacts 111 and the pads 231 respectively. Wherein, the solder 3 can be a solder ball. The filter 5 is disposed on the slope 222 through the opening 221 .

The reflective layer 7 can be coated on the bottom surface of the sensing film 21 (as shown in FIG. 7 ), or the reflective layer 7 can be coated on the top surface of the circuit board 11 (as shown in FIG. 8 ).

In addition, the present invention may have a first adhesive part 4 and a second adhesive part 6 . The first adhesive member 4 is disposed between the top surface of the circuit board 11 and the bottom surface of the ring side wall 22 , so as to glue the circuit board 11 and the chip 2 to prevent moisture from affecting the characteristics of the components. The second adhesive member 6 is disposed on the top surface of the ring sidewall 22 and contacts the filter 5 , so as to bond the chip 2 and the filter 5 . Wherein, the first adhesive part 4 and the second adhesive part 6 can be silica gel.

Please refer to FIG. 9 to FIG. 10 , which is the fourth embodiment of the present invention. Compared with the third embodiment, the main difference of this embodiment is that the inner edge of the ring side wall 22 is stepped and forms at least one stepped surface 223 . The filter 5 is disposed on the stepped surface 223 through the opening 221 .

Furthermore, the reflective layer 7 can be coated on the bottom surface of the sensing film 21 (as shown in FIG. 9 ), or the reflective layer 7 can be coated on the top surface of the circuit board 11 (as shown in FIG. 10 ).

[Features of the present invention]

(1) Mass production is possible to reduce production cost: the manufacturing method of the present invention can be mass-produced on a large scale without the need for individual production, therefore, the production cost can be greatly reduced.

(2) Improvement of yield rate: several openings 212 are provided on the outer edge of the sensing film 21 to prevent the sensing film 21 from expanding and cracking when heated, thereby improving the production yield.

(3) Avoid overlapping interference of infrared rays: the present invention arranges the optical filter 5 on the inner edge of the ring side wall 22, so that the distance between the optical filter 5 and the sensing film 21 is greatly shortened, thereby effectively avoiding Infrared overlapping interference phenomenon.

(4) Significantly reduced size: In the present invention, a part of the optical filter 5 is arranged in the space covered by the inner edge of the ring side wall 22, so that the height of the infrared thermal sensing component is greatly reduced, thereby reducing the size. Moreover, the conventional base and pins are replaced by the circuit board 11 to further reduce the size.

(5) Reduce the cost of raw materials: the present invention does not need to use the cover body, replaces the conventional base and pins with the circuit board 11, replaces the conventional bonding wire with the solder 3, and directly forms the thermistor 24 on the ring The bottom of the side wall 22, therefore, the cost of raw materials required for each infrared heat sensing component will be significantly reduced.

(6) Improve sensing sensitivity: the reflective layer 7 of the present invention can reflect the infrared rays that have penetrated the sensing film 21 back to the sensing film 21 again, so as to improve the sensing sensitivity of the infrared thermal sensing component.

(7) Wide range of applications: the overall size of the present invention is equivalent to the size of a chip 2, and compared with conventional pins, the bottom surface of the circuit board 11 of the present invention can be electrically connected, so it is equivalent to a surface mount assembly (SMD), therefore, the miniaturized infrared heat sensing component of the present invention has a wider range of applications, such as mobile phones, ear thermometers, and sensors, and allows these devices to have a reduced size space.

The above disclosures are only preferred embodiments of the present invention, and cannot limit the scope of rights of the present invention. Therefore, equivalent changes or modifications made according to the application scope of the present invention still fall within the scope of the present invention.

Claims (15)

1. A method for manufacturing a miniaturized infrared thermal sensing assembly, characterized in that the steps comprise: providing a wafer and a substrate, the wafer having a plurality of chips; Form four pads, a thermistor and an infrared thermal sensing layer on the bottom of each chip, two of the four pads are electrically connected to the thermistor, and the other two pads are electrically connected to the thermistor. Sexually connected to the infrared thermal sensing layer; fixing several solders on the four pads respectively; Carrying out back etching on the top surface of each chip, so that a sensing film and a ring side wall surrounding and connecting the sensing film are formed in each chip; docking the wafer with the substrate; heating the solders to solder each chip to the substrate; a plurality of optical filters are respectively inserted in the sidewall of the ring of each chip; and The wafer and the substrate are cut to form several infrared thermal sensing components. 2. The method of manufacturing a miniaturized infrared thermal sensing component as claimed in claim 1, wherein each of the four soldering pads forms at least one soldering pad, and the solders are respectively fixed on the four soldering pads on the pads of the substrate, and coat a first adhesive on the substrate, and after the filters are respectively inserted in the ring sidewalls of each chip, coat a top surface of each chip with a Second adhesive. 3 . The method of manufacturing a miniaturized infrared thermal sensing element as claimed in claim 1 , wherein the inner edges of the ring sidewalls are all shaped as slopes or steps. 4 . 4. The method of manufacturing a miniaturized infrared thermal sensing component as claimed in claim 1, wherein the sensing film is formed with several openings. 5 . The method of manufacturing a miniaturized infrared thermal sensing element as claimed in claim 1 , further comprising coating a reflective layer between the sensing film and the substrate. 6 . 6. A method for manufacturing a miniaturized infrared thermal sensing assembly, characterized in that the steps include: providing a wafer and a substrate, the wafer having a plurality of chips; Form four pads, a thermistor and an infrared thermal sensing layer on the bottom of each chip, two of the four pads are electrically connected to the thermistor, and the other two pads are electrically connected to the thermistor. Sexually connected to the infrared thermal sensing layer; fixing several solders on the four pads respectively; Carrying out back etching on the top surface of each chip, so that a sensing film and a ring side wall surrounding and connecting the sensing film are formed in each chip; dicing the wafer into a plurality of wafers; bonding each die to the substrate; heating the solders to solder each chip to the substrate; a plurality of optical filters are respectively inserted in the sidewall of the ring of each chip; and The substrate is cut to form several infrared thermal sensing components. 7. The method of manufacturing a miniaturized infrared thermal sensing component as claimed in claim 6, wherein each of the four pads is formed with at least one pad, and the solders are respectively fixed on the four pads on the pads of the substrate, and coat a first adhesive on the substrate, and after the filters are respectively inserted in the ring sidewalls of each chip, coat a top surface of each chip with a Second adhesive. 8 . The method for manufacturing a miniaturized infrared thermal sensing element as claimed in claim 6 , wherein the inner edges of the ring sidewalls are all shaped as slopes or steps. 9 . 9. The method of manufacturing a miniaturized infrared thermal sensing component as claimed in claim 6, wherein the sensing film is formed with several openings. 10 . The method for manufacturing a miniaturized infrared thermal sensing element as claimed in claim 6 , further comprising coating a reflective layer between the sensing film and the substrate. 11 . 11. A miniaturized infrared thermal sensing component, characterized in that it comprises: A chip, which has a sensing film and a ring side wall surrounding and connected to the sensing film, an infrared thermal sensing layer is formed in the sensing film, an opening is formed on the top surface of the ring side wall, and the ring side four pads and a thermistor are formed on the bottom of the wall; and a filter, which is arranged on the inner edge of the ring side wall through the opening; Wherein, two of the four pads are electrically connected to the thermistor, and the other two pads are electrically connected to the infrared thermal sensing layer. 12 . The miniaturized infrared thermal sensing component according to claim 11 , wherein the inner edge of the side wall of the ring is inclined or stepped. 13 . 13. The miniaturized infrared heat sensing component as claimed in claim 11, wherein a plurality of openings are formed on the outer edge of the sensing film. 14. The miniaturized infrared thermal sensing assembly according to claim 11, further comprising a circuit board and several solders, the top surface of the circuit board is opposite to the bottom surface of the sensing film, and the top surface of the circuit board Several contacts are formed, each of the four pads forms at least one pad, and the solders are respectively arranged between the contacts and the pads of the four pads, and the contacts on the top surface of the circuit board face extending downward to form several lines connecting the top surface and the bottom surface of the circuit board. 15. The miniaturized infrared thermal sensing component as claimed in claim 14, wherein a reflective layer is coated on the bottom surface of the sensing film or the top surface of the circuit board.

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