JP2007171159A - Infrared detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin and small-sized and low-cost infrared detector, capable of easily forming a space for thermal insulation of the infrared detector. <P>SOLUTION: The infrared detector A is constituted, enclosing in a circuit block 3 for mounting a pyroelectric element X, iC16, a chip-like electronic component 17 inside of a case, composed of a stem 1 and a cap 2. The circuit block 3 comprises a support receiving part for supporting both sides of the pyroelectric element X, at a convex part forming as a whole a concavo-convex part on the upper surface of the upper part of a resin layer 10, a concave part 11 as the space for the thermal insulation layer at the lower part of the detection part of the pyroelectric element X at the concave part position. At a second resin layer 8 below the concavo-convex part, IC16 mounted on the upper surface of a circuit substrate 7 is embedded integrally in the constitution. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an infrared detector in which infrared rays emitted from a human body or the like are detected by an infrared detection element.

  In general, a so-called pyroelectric element is often used as an infrared detecting element for detecting a human body by the amount of change in infrared rays. Infrared detectors using such pyroelectric elements are used for load control such as lighting in addition to detection of security entry. As this infrared detector, for example, as shown in FIG. 12, the infrared rays generated by the movement of the human body are condensed on the light receiving portion of the pyroelectric element X by the lens 100, and the pyroelectric element X generated according to the change of the infrared rays. After the signal due to polarization is converted into a voltage signal by the current-voltage conversion circuit 102, a predetermined frequency band is selectively amplified by the band-pass amplifier 103, and "H", "L" There is a type that outputs a "level detection signal, and the detection signal output from the window comparator 104 is used for load control.

  By the way, in the conventional infrared detector, as shown in FIG. 13A, both ends of the pyroelectric element X are bridged between the convex support portions 105 and 105 made of electronic circuit elements provided on the circuit board 104. The pyroelectric element X is floated from the circuit board 104 and a space Y for thermal insulation is provided between the light receiving surface of the pyroelectric element X and the back circuit board 104. The pyroelectric element X receives infrared rays. In some cases, the sensitivity of the pyroelectric element X is increased by preventing infrared energy from escaping. Since the charge of the pyroelectric element X is very small, very large amplification must be performed. If a slight noise enters the output of the pyroelectric element X due to the influence, the band-pass amplifier 103 in the subsequent stage Noise is also amplified, making it difficult to distinguish the original signal from noise. Therefore, as shown in FIG. 13A, a package structure in which the pyroelectric element X and the circuit board 104 are sealed in a container made of a metal cap (CAN) 106 and a stem 107 so as to provide a shield is provided. Noise is cut off (for example, Patent Document 1). In FIG. 13A, reference numeral 108 denotes an output terminal, 109 denotes an infrared passage window of the cap 105, and the infrared passage window 109 is provided with a band-pass type optical filter 110 that passes only infrared rays in a predetermined frequency range. Yes.

  By the way, since the infrared detector having the package structure disclosed in Patent Document 1 has only an impedance conversion circuit inside, it has a configuration as shown in FIG. In addition to the infrared detector in which the pyroelectric element X is housed in a container composed of a cap 106 and a stem 107 shown in b), an external electronic circuit element 113 such as a lens 112, a capacitor, a resistor, and an IC chip is mounted. In general, the above-mentioned optical filter, window comparator, timer, and output amplifier are added.

On the other hand, as shown in FIGS. 14A to 14C, a three-dimensional circuit block (MID substrate) 200 manufactured by a resin molded product has a pyroelectric element X, a band-pass amplifier, and an electronic circuit constituting a window comparator. There has been provided an infrared detector that is miniaturized by mounting the element 201 and enclosing and sealing it in a container composed of a cap 106 and a stem 107 (for example, Patent Document 2). The three-dimensional circuit block 200 used for the infrared detector is a vertically long block that has a vertical surface and a vertical surface, and has an electronic circuit element 201 mounted on the vertical surface. In FIG. 2, a recess 202 for forming a space for thermal insulation of the pyroelectric element X is integrally formed, and the pyroelectric element X is bridged between both ends of the recess 202.
JP-A-5-332829 (FIG. 1, paragraph numbers 0015 to 1006) Japanese Patent No. 3211074 (FIGS. 6 to 13 and paragraph numbers 0018 to 0021)

  In the case of the infrared detector disclosed in the above-mentioned Patent Document 1, the light receiving surface of the pyroelectric element X is arranged on the circuit board 104 so that the infrared energy does not escape when the pyroelectric element X receives the infrared light. Although the support part 105 which floats more is provided, since this support part 105 is a separate component from the circuit board 104, a separate component mounting process is required, which causes a cost increase. Further, when the support part 105 is provided as a separate part, there is a problem that the height of the support part 105 changes due to an attachment error, and the thermal insulation effect of the pyroelectric element X varies. Further, in the case of the infrared detector of Patent Document 1, an external circuit unit as shown in FIG. 12 is necessary, and therefore the circuit scale becomes very large because the electronic circuit component 113 is mounted on a large printed board 111. However, there is a problem that the recent demands for miniaturization and thinning cannot be answered, and circuit components are susceptible to electromagnetic noise when they are externally attached. It was. In order to prevent this, there is a problem that it is necessary to attach a large shield plate to the external circuit portion.

  On the other hand, the one using the three-dimensional circuit block 200 like the infrared detector disclosed in Patent Document 2 can solve the problems of the infrared detector disclosed in Patent Document 1 to some extent.

  That is, since the recess 202 for directly floating the pyroelectric element X is formed in the three-dimensional circuit block 200, the number of parts can be reduced and the cost can be reduced, and the electronic circuit element 201 is stored in a container made of a metal cap and stem. By using the CAN package, it is possible to reduce the size, and it is also possible to reduce the size of the circuit unit by making the bandpass amplifier and the window comparator into an IC. In addition, since the distance between the pyroelectric element X and the input part of the bandpass amplifier can be shortened, external noise is less likely to enter than a method of amplifying with an external component using a printed circuit board, and the configuration is strong against noise. Further, by housing and shielding the pyroelectric element X and the entire circuit unit in a container made of a metal cap and stem, there is an advantage that a configuration extremely resistant to external noise can be realized.

  However, in the infrared detector disclosed in Patent Document 2, an electronic component or an IC is mounted on a circuit portion in which the three-dimensional circuit block 200 stands vertically and forms a front surface and a back surface. Therefore, it is inevitable that the package becomes vertically long.

  For this reason, the thickness of a device to which the infrared detector disclosed in Patent Document 2 is restricted is limited, making it difficult to reduce the thickness, and the demand for further miniaturization and reduction in thickness cannot be met. In addition, when the three-dimensional circuit block 200 is downsized to reduce the overall size, the following two problems occur.

  First, there is a problem of lack of mounting space. That is, in the above-described three-dimensional circuit block 200, a portion where the front surface and the back surface are formed upright by the subordinate can be taken as a circuit space. However, if the three-dimensional circuit block 200 is simply reduced in size, The space for mounting circuit components cannot be secured, and downsizing cannot be realized.

  The second problem is due to the fact that the distance between the output of the pyroelectric element X and the amplified subsequent stage output is close. That is, since the change in the electric charge of the pyroelectric element X is very weak, the subsequent circuit amplifies the femtoampere level current change to several hundred millivolt level. For this reason, it is necessary to sufficiently separate the pyroelectric element X from the final stage output so that even a small signal of the final stage output farmland does not affect the pyroelectric element X. However, when the distance is about 1 mm, there arises a problem that a phenomenon such as an oscillation phenomenon or a deterioration in frequency characteristics occurs due to capacitive coupling between the pyroelectric element X and the final output stage.

  The same problem occurs between the pyroelectric element and the power supply terminal. That is, at the power supply terminal, in addition to the supplied voltage, external (disturbance) noise such as superimposed noise from the commercial power supply and radiation noise from the mobile phone also rides. Accordingly, when the pyroelectric element and the power supply terminal are close to each other, there may be a problem due to capacitive coupling between the pyroelectric element and the power supply terminal.

  The present invention has been made in view of the above-described points, and its object is to easily form a space for thermal insulation of an infrared detection element, which is thin, small and low-cost infrared detection. Is to provide a vessel.

In order to achieve the above object, the invention of claim 1 is an infrared detector that accommodates a circuit block on which an infrared detection element, an electronic component, and an IC are mounted in a package container,
The circuit block has a concave and convex portion integrally formed on the upper surface of the resin layer, and a support receiving portion that supports both sides of the infrared detection element at a convex portion, and a recess for the heat insulating layer below the infrared detection element. And the electronic circuit elements such as ICs and chip-shaped electronic components mounted on the first substrate on which the wiring pattern constituting the circuit part is formed, and the resin below the concave-convex shape part. It is characterized by being embedded in the layer.

  According to the first aspect of the present invention, the space for forming the heat insulating layer of the circuit block and the infrared detecting element can be easily formed integrally with the first resin layer, and the electronic circuit configuration such as an IC or an electronic component can be formed. By embedding the element in the second resin layer by integral molding, it becomes possible to secure a space (mounting area) for mounting the electronic circuit element that has been an obstacle to downsizing in the standing direction, greatly reducing the cost As a first substrate on which an electronic circuit element is mounted, a printed board that can form a fine fine pitch circuit by a general circuit board forming method or a board that uses a thin copper foil can be used. The circuit block including the resin layer and the substrate thereon can be formed into a multilayer substrate structure that can be easily manufactured by pressing.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the resin layer is a resin layer obtained by curing a thermosetting resin mixed with an inorganic filler.

  According to the invention of claim 2, by using a thermosetting resin having a good fluidity, the thermosetting resin has a property of having a good filling property around the electronic circuit element to be embedded integrally and having a low water absorption property against humidity and the like. Since the electronic circuit element is integrally embedded in the resin layer, the influence of humidity on the electronic circuit element can be reduced, and further, since the inorganic filler is filled, the linear expansion coefficient of the resin layer is small, and the uneven portion is mechanically The characteristics are stable.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the first resin layer in which the concave and convex portions are formed on the upper surface of the resin layer, and the second resin layer in which the electronic circuit element is embedded integrally. A shield layer having a specific potential or a ground potential is provided between the first and second resin layers.

  According to the invention of claim 3, a structure in which the infrared detecting element supported and mounted by the support receiving portion on the upper surface of the first resin layer and the lower circuit portion across the shield layer are not electrically capacitively coupled. Therefore, very high sensitivity and stable output can be obtained.

  According to a fourth aspect of the invention, in the third aspect of the invention, the shield layer is formed on a second substrate made of a thermosetting resin.

  According to invention of Claim 4, since a shield layer is formed in the 2nd board | substrate consisting of a thermosetting resin, it can arrange | position integrally with the 1st, 2nd resin layer.

  According to a fifth aspect of the present invention, in the fourth aspect of the invention, the second substrate includes the first resin layer, the second resin layer, and the electronic circuit incorporated in the second resin layer. When the circuit block is formed by heating and pressing the first substrate on which an element is mounted, the first and second resin layers are disposed between the first and second resin layers and are heated and pressed. It is characterized by being integrated.

  According to the invention of claim 5, when the first and second resin layers of the circuit block are integrally formed by the heating press, the second substrate of the shield layer can be formed at the same time, thereby reducing the number of steps. Therefore, the cost can be reduced.

  According to a sixth aspect of the present invention, in the third aspect of the present invention, the shield layer is formed of a copper foil layer formed on the upper surface of the second resin layer.

  According to the sixth aspect of the present invention, the shield layer is made of copper foil, so that the thickness thereof can be made extremely thin, so that the circuit block can be thinned.

  According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the copper foil layer is formed when the first substrate is integrated by a heat press so that the electronic circuit element is incorporated in the second resin layer. Further, the first resin layer is integrated on the second resin layer, and the first resin layer is integrated on the second resin layer by a hot press to form the circuit block. The resin layer is interposed between the second resin layer and the second resin layer.

According to the invention of claim 7, when the first and second resin layers of the circuit block are integrally formed by a heat press, the copper foil layer of the shield layer is formed of the first resin layer and the second resin layer. The number of steps for forming the circuit block can be reduced and the cost can be reduced. The invention according to claim 8 is the invention according to any one of claims 1 to 7. The circuit pattern connecting the detection element, the shield layer, and the electronic circuit element integrally embedded in the second resin layer is joined by a through hole including a through hole penetrating the first and second resin layers. It is characterized by.

  According to the eighth aspect of the present invention, the electrical connection between the layers can be performed by the through hole made of the through hole which is simple in process and low in cost.

  The invention according to claim 9 is the invention according to any one of claims 1 to 8, wherein the electronic circuit element embedded in the resin layer is only an IC.

  According to the ninth aspect of the present invention, it is possible to separate the mounting surface of the IC and the chip-shaped electronic component, and therefore, it is not necessary to take measures against the problem in the mounting process of these electronic circuit elements, and the process is simplified. Further, by embedding an IC that is much thinner than the thickness of the chip-shaped electronic component, the thickness of the entire circuit block can be reduced.

  The invention of claim 10 is characterized in that, in the invention of any one of claims 1 to 8, the electronic circuit element integrally embedded in the resin layer is only a chip-shaped electronic component.

  According to the invention of claim 10, there is an advantage in the mounting process as in the invention of claim 9, and a chip-like electronic component that is connected by solder and has a high connection strength compared to the connection of the IC to be flip-chip mounted is resin. Since it is embedded in the layer, the mounting part is difficult to peel off even when subjected to stress during the embedded process, and even if a defect occurs during the embedded process, the cost of chip-like electronic components is lower than that of the IC. Cost can be reduced.

  According to an eleventh aspect of the present invention, in the invention according to any one of the first to tenth aspects, the container is composed of a device base and a cap deposited on the device base, and a spacer is provided on the upper surface of the device base. In addition, the circuit block is mounted via the lands, and lands formed on the lower surface of the circuit block are electrically joined to the upper ends of the terminal pins protruding from the upper surface of the instrument base.

  According to the eleventh aspect of the present invention, the circuit block can be joined to the connection pin of the instrument base with a simple configuration.

  According to a twelfth aspect of the present invention, in the invention of the eleventh aspect, the spacer has an insertion portion for passing the terminal pin portion positioned between the terminal pin and the joint portion of the circuit block in the vertical direction. It is characterized by being provided to be opened on the outer peripheral surface of the.

  According to the invention of claim 12, the state in which the upper ends of the connection pins that have passed through the insertion portion of the spacer are joined can be visually observed from the opening of the insertion portion. The process can be managed and the cost can be reduced by improving the yield.

  According to the present invention, the space for forming the heat insulating layer of the circuit block and the infrared detection element can be easily formed integrally with the first resin layer, and the electronic circuit components such as IC and electronic components can be formed in the second manner. By embedding in the resin layer by integral molding, it is possible to secure a space (mounting area) for mounting electronic circuit elements that has been an obstacle to downsizing in the standing direction, and at a low cost, it is significantly thin and compact As a substrate for mounting electronic circuit elements, a printed circuit board that can form a fine fine pitch circuit by a general circuit board forming method or a board that uses a thin copper foil can be used. A circuit block including the resin layer and the substrate can be formed into a multilayer substrate structure that can be easily manufactured by pressing.

Hereinafter, embodiments of the infrared detector of the present invention will be described.
(Embodiment 1)
The infrared detector A of the present embodiment is a container for a CAN package comprising a stem 1 as a disk-shaped metal stand and a metal cap 2 as shown in FIGS. 1 (a) and 1 (b). And a circuit block 3 in which a pyroelectric element X or the like as an infrared detecting element is mounted.

  The stem 1 protrudes from the peripheral part one step above the peripheral part to form the mounting part 1a of the circuit block 3, the cap 2 has an opening at the bottom, and only the infrared ray in a specific frequency range is cap 8 at the center of the ceiling part. A rectangular infrared transmission window 5 fitted with a bandpass optical filter 4 to be incident on the inside is opened, and the periphery of the mounting portion 1a of the stem 1 on which the circuit block 3 is mounted via a spacer 6 made of an insulating material. The cap 2 is attached onto the stem 1 by mounting and fixing the flange 2b formed to protrude from the lower edge of the cap 2 on the annular step 1b, thereby sealing the circuit block 3 to be embedded integrally and providing an electromagnetic shield. To do.

  The circuit block 3 includes a circuit board 7 that is a first board formed of glass epoxy or the like, a second resin layer body 8 that is arranged on the circuit board 7, and an arrangement on the resin layer body 8. The first and second substrate units are composed of a second substrate 9 made of glass epoxy or the like, and a first resin layer body 10 arranged and formed on the substrate 9. The resin layer bodies 10 and 8 are formed so as to be integrally laminated on the substrates 7 and 9 using a method described later.

  As shown in FIG. 2 (b), the resin layer body 10 has a concave portion 11 made of a long hole formed in the central portion and the upper surface of the peripheral portion of the concave portion 11. Reference numeral 11 denotes a space part for thermal insulation by floating the detection part of the pyroelectric element X in the air, and the upper surface portions on both sides of the concave part 11 constitute a support receiving part that supports both sides of the pyroelectric element X. The support receiving portion is provided with lands 12 and 12 for joining the electrodes on both sides of the pyroelectric element X.

  In addition, the convex support receiving part which supports the both sides of the pyroelectric element X is formed in the upper surface of the resin layer body 10, and the upper surface of the resin layer body 10 is made uneven | corrugated shape, The space part (concave part) between convex support receiving parts Thus, an air layer that thermally insulates the detecting portion of the pyroelectric element X may be formed.

  A space portion is formed between the detecting portion (light receiving surface) of the pyroelectric element X and the lower substrate 9 by the concave and convex portions 11 having such a concave and convex shape, and an air layer for thermal insulation is secured thereby. Highly sensitive measurement is possible. Each land 12 penetrates the upper and lower surfaces of the resin layer body 8 by a circuit pattern 13 having one end connected thereto, and is electrically connected to a through hole 14 having an inner surface plated with through holes.

  The substrate 9 has a shield layer 15 formed of a metal foil (for example, a copper foil) for preventing an oscillation phenomenon due to capacitive coupling between the output of the pyroelectric element X and a subsequent amplification unit (bandpass amplifier). ) As shown on the upper surface (or lower surface or both surfaces) of the glass epoxy substrate. Of course, the shield layer 15 may be formed of only a copper foil or a metal plate layer as will be described later. In general, the potential of the shield layer is set to the ground potential, but any shield can be used as long as it maintains a specific potential, since it functions as a shield. Further, when the output of the pyroelectric element X is not amplified too much by the amplifying unit (bandpass amplifier), an oscillation phenomenon due to capacitive coupling or the like is unlikely to occur, so this shield layer 15 is not necessary. In the illustrated example, the substrate 9 Can be omitted.

  The uppermost circuit board 7 is a surface on which an IC 16 constituting a band pass amplifier or window comparator is mounted as shown in FIG. 2D, and the lower surface is a chip-like electronic component as shown in FIG. 17 is mounted on each surface, and a circuit pattern for forming a circuit unit necessary as an infrared detector is formed on each surface by connecting these electronic circuit elements. The chip-shaped electronic component 17 is reflow soldered. The IC 16 is mounted on the circuit pattern by flip chip. Generally, the line and space for flip mounting is 100 μm or less, and fine pitch processing of a glass epoxy substrate is performed. This circuit pattern may be formed simply by a thin copper foil. This processing is difficult when forming a circuit using a lead frame.

FIG. 1C shows the circuit pattern omitted. As described above, by separating the mounting surface of the IC 16 and the chip-like electronic component 17, the following effects on the mounting process can be obtained. Yes. That is, when the IC 16 is connected by flip chip and the chip-shaped electronic component 17 is connected by reflow soldering, if the flip chip and the chip-shaped electronic component 17 are mixed on the same surface, the connection process is performed twice on the same substrate surface. Will occur. For this reason, there is a problem that screen printing cannot be performed when the chip-like electronic component 17 is mounted on the substrate surface and the solder is applied after the IC 16 is mounted. Conversely, when the IC 16 is mounted after the chip-shaped electronic component 17 is mounted, the IC 16 mounting jig does not fit well for the chip-shaped electronic component 17, or the solder 18 or the like for connecting the chip-shaped electronic component 17. Due to the influence, there is a problem that the connection land of the IC 16 on the substrate is contaminated. On the other hand, like the circuit board 7 of the present embodiment, by separating the surface on which the IC 16 is mounted and the surface on which the chip-shaped electronic component 17 is mounted, a countermeasure for the above-described problem in the mounting process becomes unnecessary. There is an effect that the process is simplified. The IC 16 to be mounted may be mounted on the circuit board 7 using an IC 16 of a form such as a QFP that is molded and packaged, in addition to a structure in which a bare chip such as flip chip mounting is directly bonded to the circuit board 7.

  The resin layer body 8 arranged and formed between the upper part of the circuit board 7 and the board 9 is an entire circuit block 3 having a multilayer board unit structure by embedding an IC 16 mounted on the upper surface side of the circuit board 7 by integral molding. The thickness can be reduced. If the thickness of the IC 16 mounted on the circuit board 7 is much thinner than the thickness of the chip-shaped electronic component 17, the thickness of the resin layer body 8 in which the IC 16 is embedded can be reduced. As a result, the entire circuit block 3 is obtained. Further reduction in thickness can be achieved.

  The circuit block 7, the resin layer body 8, the substrate 9, and the resin layer body 10 configured as described above are laminated to form a multilayer substrate unit, and the circuit block 3 is configured. The output is supplied to the circuit portion including the IC 16 and the electronic component 17 through the through hole 14 of the substrate 9, the through hole 14 of the resin layer body 8, and the through hole 14 of the circuit board 7 through the through hole 14. And the shield layer 17 is connected to a predetermined potential portion (for example, ground potential). Instead of the through hole, the connection between layers may be connected by filling the through hole with a conductive paste (conductive adhesive), but via holes are formed in each layer to fill the hole with the conductive paste. In addition, the method of making a multilayer substrate by stacking the next layers is not suitable for cost reduction because the process is complicated and the accuracy at the time of bonding is required. When the through-holes 14 are used, the layers can be connected by a single drilling process, and the layers can be connected by a simple construction method.

  Next, a process for forming the circuit block 3 having the multilayer substrate unit structure described above will be briefly described with reference to FIG.

First, as shown in FIG. 3A, a circuit board 7 on which an IC 16 is previously mounted on an upper surface and a board 9 on which a shield layer 15 is formed in advance are prepared, and a B stage state is provided between the circuit board 7 and the board 9. A sheet-like resin material 20 that is highly filled with an inorganic filler such as silica (SiO ₂ ) in the epoxy resin material (for example, 85 wt%), has high elongation and tensile strength, is tough at room temperature, and is not easily torn, for example. Three sheets are stacked on the circuit board 7, the substrate 9 is stacked on the resin material 20, and the two resin materials 20 are stacked on the substrate 9, and then placed in a press mold. In this charged state, the resin material 20 is heated and melted while being evacuated (for example, 100 ° C.), and pressurized (for example, 3 Mpa) for a certain time. As a result, the dissolved resin flows into the irregularities of the IC 16 on the circuit board 7 and the gaps below the IC 16. Then, the temperature is raised at a predetermined temperature (for example, 175 ° C.) to be completely cured. By this curing, the resin layer body 8 in which the IC 16 is integrally embedded is formed integrally with the circuit board 7 on the circuit board 7, and the resin layer body 8 and the uppermost layer are cured and formed above the resin layer body 8. The substrate 9 is integrated with the resin layer body 10 as shown in FIG. Further, the recess 11 is simultaneously formed in the resin layer body 10 by the mold. In this way, after the substrate 9, the resin layer body 8, and the circuit board 7 are integrated, the through hole 14 penetrating each layer is formed by the router.

  Next, as shown in FIG. 3C, lands 12 and circuit patterns 13 are formed on the upper surface of the resin layer body 10 by general electroless plating, and through holes 14 are plated for interlayer connection. The electronic component 16 and the pyroelectric element X are formed by forming a circuit pattern on the lower surface of the circuit board 7, a land 12 of the resin layer body 10, and a circuit pattern 13 by etching using a general patterning method. The board unit of the circuit block 3 before mounting is completed as shown in FIG.

Naonetsu curable The resin phenolic resin may in such cyanate resin, and as the inorganic filler, aluminum oxide other than silica _{(Al 2 O} 3), magnesium oxide (MgO), boron nitride (BN) or the like one or Two or more types may be mixed.

  The circuit block 3 is completed by bridging and electrically connecting the pyroelectric elements X between the lands 12 and 12 on both sides of the concave portion 11 of the resin layer body 10 formed as described above. The circuit block 3 is mounted via the spacer 6 on the mounting portion 1a. In addition, it fixes with the adhesive agent between the circuit block 3 and the spacer 6, and between the spacer 6 and the mounting part 1a.

  Here, the stem 1 comprising the container of the present embodiment with the cap 2 is composed of a three-legged connection pin 19... And a metal (SPC, Kovar) holding these connection pins 19 as shown in FIG. The circuit board 7 of the circuit block 3 is provided with lands 12 ′ connected to the connection pins 19 of the stem 1 on the lower surface, and these lands 12 ′ are connected to the terminal pins 19. Are joined by a conductive material 21 such as silver paste or solder. Since the electronic component 17 is mounted on the lower surface of the circuit board 7, the spacer 6 for preventing the electronic component 17 from coming into contact with the mounting portion 1 a of the stem 1 is provided with the lower surface of the circuit block 3 and the mounting portion 1 a of the stem 1. It is set as the structure which interposes between the upper surfaces of and provides a distance. Of course, when the electronic component 16 is not mounted on the lower surface of the circuit board 7, the spacer 6 is unnecessary.

  By the way, as shown in FIGS. 4 (a) and 4 (c), the spacer 6 has three insertion portions 6a that protrude from the stem 1 and pass through the portions of the connection pins 19... Is provided. The outer surface of the peripheral portion of the spacer 6 is opened in these insertion portions 6a, and the circuit block 3 is mounted on the stem 1 via the spacer 6 as shown in FIGS. 5 (a) and 5 (b). Then, the state where the upper ends of the connection pins 19 through the insertion portion 6a of the spacer 6 are joined to the land 12 'on the lower surface of the circuit board 7 by the conductive material 21 can be visually observed from the side opening of the insertion portion 6a. It is said. In other words, a visual inspection is performed before the cap 2 described later is put on at the time of manufacturing, so that the manufacturing process can be managed and the cost can be reduced by improving the yield.

Thus, after the circuit block 3 on which the pyroelectric element X is mounted and the stem 1 are bonded and fixed, the flange portion 2a of the metal cap 2 in which the optical filter 5 is mounted on the infrared passage window 4 is connected to the annular step portion of the stem 1 By welding in a state of being placed on 1b, the inside of the container composed of the cap 2 and the stem 1 is sealed to form an airtight structure, and a desired infrared detector A having a cross-sectional structure as shown in FIG. 6 is completed. It will be. 6 is an insulating material made of glass or the like for insulating the connection pins 19 from the stem 1. By adopting a CAN package structure, it is possible to provide a high shielding effect against external noise, and airtightness. The structure prevents intrusion such as humidity and ensures high environmental resistance. As described above, the optical filter 4 allows only infrared rays in a specific wavelength range to pass therethrough, and has an effect of reducing the influence of disturbance light. In the case of human body detection, a coating is applied so that light having a wavelength of about 4 μm or more is passed and infrared rays lower than that are cut.

  By being configured as described above, the infrared detector A of the present embodiment is thin, small, and highly reliable. Further, it is possible to solve the problem of capacitive coupling caused by the distance between the output of the pyroelectric element X and the amplified output of the subsequent stage being reduced by the shield layer 15 of the substrate 9. That is, by providing the shield layer 15 having a specific potential or a ground potential in the lower layer of the pyroelectric element X, the capacitive coupling between the pyroelectric element X and the circuit portion thereof is cut off, thereby achieving very high accuracy. High measurement is possible. In particular, the effects of external (disturbance) noise such as superimposed noise from commercial power supplies and radiation noise from mobile phones that are riding on the power supply section, without causing phenomena such as oscillation or frequency characteristic degradation due to capacitive coupling Will be able to prevent.

  The configuration of the circuit section of the infrared detector A of the present embodiment is basically the same as the circuit of FIG. 12, but the output amplified by the bandpass amplifier 102 in FIG. In this case, since the change in the output of the pyroelectric element X can be viewed as an analog signal, it is effective for applications such as a case where the comparator in the subsequent stage has many thresholds or a control where the analog signal itself is used. Is.

  Further, as shown in FIG. 7, instead of forming the plate-like resin layer body 10, only the convex portion 23 that becomes a support portion for supporting the pyroelectric element X is formed of the above-described resin, A space for thermal insulation may be formed between the upper surface of the substrate 9 to increase the sensitivity. The land 12, the circuit pattern 13, and the through hole 14 are formed on the upper surface of the convex portion 23.

  In this embodiment, the pyroelectric element X is used as the infrared detection element, but it is of course possible to use an infrared detection element such as a bolometer or a thermopile.

FIG. 8 shows an example of an infrared detection element X ′ using a thermist type sensing element. The infrared detection element X ′ is formed on the base 25 on the lower electrode 26a and the amorphous silicon film formed on the lower electrode 26a. An infrared detection unit 26 including a resistor layer 26b made of the above and an upper electrode 25c formed on the resistor layer 26b is provided, and an infrared absorption layer 27 whose surface is a light receiving surface is provided on the infrared detection unit 26 In the same manner as in the case of the pyroelectric element X, it is used by being mounted on the recess 7 formed on the surface of the resin layer body 10. 28a and 28b are pads, and 29a and 29b are metal wirings.
(Embodiment 2)
In the first embodiment described above, the IC 16 is integrally embedded in the resin layer body 8, but in this embodiment, the IC 16 is mounted on the lower surface of the circuit board 7 as shown in FIGS. 9A and 9B. A chip-like electronic component 17 is mounted on the upper surface, that is, the resin layer body 8 side, and the electronic component 17 is embedded in the resin layer body 8 integrally.

  Since other configurations are the same as those of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  Thus, in the configuration of the present embodiment, the advantage of separating the surface on which the chip-shaped electronic component 17 and the IC 16 are mounted is the same as that of the first embodiment, but compared with the connection of the IC 16 using a flip chip or the like, the chip-shaped electronic Since the component 17 is connected by the solder 18, the connection strength is high, and there is an advantage that the mounting portion is not easily peeled off even when stress is applied when embedded in the resin layer body 8 by integral molding. In addition, even if a defect occurs when embedding a component, the cost of the chip-shaped electronic component 17 is lower than that of the IC 16, and thus there is an advantage that the loss cost can be reduced.

In addition, when the problem at the time of mounting IC16 and the chip-shaped electronic component 17 on the same surface can be solved, it is of course possible to embed both in the resin layer body 8, and it is limited to the first and second embodiments. Is not to be done.
(Embodiment 3)
In the first and second embodiments, the substrate 9 provided with the shield layer 15 made of copper foil is used. However, in this embodiment, the circuit block 3 is made thin by forming the shield layer 15 only with the copper foil. This is different from the first and second embodiments.

  The circuit block 3 in this embodiment will be described with reference to the manufacturing process shown in FIG.

First, as shown in FIG. 10A, a B-stage epoxy resin material is highly filled with an inorganic filler such as silica (SiO ₂ ) on a circuit board 7 on which an IC 16 has been previously mounted (for example, 85 wt%). In addition, three sheet-like resin materials 20 having high elongation and tensile strength, toughness and not easily torn at room temperature, and the copper foil 24a are stacked, and the above-described resin material 20 is further formed on the substrate 9. Are put into a press mold in a state where two sheets are stacked, and heated (for example, 100 ° C.) while being evacuated in this state, the resin material 20 is thermally melted and pressurized for a certain time (for example, 3 MPa) To do. As a result, the dissolved resin flows into the irregularities of the IC 16 on the circuit board 7 and the gaps below the IC 16. Then, the temperature is raised at a predetermined temperature (for example, 175 ° C.) to be completely cured. By this curing, the resin layer body 8 in which the IC 16 is integrally embedded is formed integrally with the circuit board 7 on the circuit board 7, and the copper foil 15 ′ is integrated with the upper surface portion of the resin layer body 8 (FIG. 10). (B)).

  Thereafter, in FIG. 10C, the shield layer 15 is formed by patterning the copper foil 24a into a predetermined shape. After this patterning, as shown in FIG. 10 (d), two pieces of the same resin material 20 as described above are stacked on the copper foil 24a and the copper foil 24b is stacked and heated and pressed in the same manner as described above to form copper on the resin layer body 8. The resin layer body 10 is integrated through the foil 24 a and the copper foil 24 b is integrated on the upper surface of the resin layer body 10.

  At this time, as shown in FIG. 10E, the concave portion 11 is formed in the center of the upper surface of the resin layer body 10 by a mold. After this step, the through hole 14 penetrating each layer is formed by the router, and the copper foil 24b and the copper foil on the lower surface of the circuit board 7 are patterned into a predetermined shape to form the land 12, the circuit pattern 13, and the like.

  If the chip-like electronic component 17 is joined to the circuit pattern on the lower surface side of the circuit board 7 after this patterning with the solder 18 or the like, the circuit block 3 is obtained as shown in FIG.

  According to the circuit block 1 of the present embodiment, since the shield layer 15 is formed of only a single copper foil, the circuit block 1 can be made thinner than the first and second embodiments. Incidentally, when the shield layer 15 is formed by using the substrate 9 used in the first and second embodiments, the thickness is several hundreds μm or more, whereas the thickness is about 10 μm if only the copper foil is used. It becomes possible.

Since the configuration other than the circuit block 1 is the same as that of the first or second embodiment, illustration and description thereof are omitted.
(Embodiment 4)
In the first to third embodiments described above, the IC 16 is flip-mounted on the circuit board 7, but in this embodiment, the IC 16 is mounted by wire bonding 31.

  In the case of the present embodiment, the circuit block 3 is formed by mounting the IC 16 on the lower surface of the circuit board 7 and embedding the electronic component 17 in the resin layer body 8 as shown in FIG. ing. When mounting the circuit block 3 on the stem 1, as shown in FIG. 11B, the spacer 6 is placed on the surface side where the IC 16 is mounted, and the IC 16 is placed in the central hole 6b of the spacer 6, The spacer 6 is bonded and fixed to the circuit board 7, and after this bonding and fixing, as shown in FIG. 11C, the center hole 6b is filled with a resin 30 and sealed, and then the circuit block is connected via the bonded and fixed spacer 6. 3 is mounted on the mounting portion 1a of the stem 1, and the spacer 6 is bonded and fixed to the mounting portion 1a.

  Since other configurations may be any of the configurations of the first to third embodiments, illustration and description are omitted here, and the same reference numerals are given to the same components. Further, even when the IC 16 is embedded in the resin layer body 8, it may be adopted in the configuration of the first embodiment as long as the wire is not broken during the heat press.

(A) is a perspective view of Embodiment 1, (b) is a perspective view with a cap removed, and (d) is an exploded perspective view in which a part of a circuit block can be omitted. (A) is sectional drawing of the circuit block used for Embodiment 1, (b) is a top view of the 1st resin layer body used for the circuit block of Embodiment 1, (c) is a board | substrate used for the circuit block of Embodiment 1. 9 is a top view of the circuit board used in the circuit block of the first embodiment, and FIG. 9E is a bottom view of the circuit board used in the circuit block of the first embodiment. It is explanatory drawing of the manufacturing process of the circuit block used for Embodiment 1. FIG. (A) is a perspective view of the spacer used for Embodiment 1, (b) is a top view of the spacer used for Embodiment 1. FIG. (A) is a front view of the state in which the circuit block is mounted on the stem of the first embodiment, (b) is an enlarged perspective view of a main part that can be partially omitted in the state in which the circuit block is mounted on the stem of the first embodiment. It is. 1 is a cross-sectional view of Embodiment 1. FIG. 6 is a cross-sectional view of another example of a circuit block used in Embodiment 1. FIG. It is an expanded sectional view of the principal part of the example using another infrared detecting element used for Embodiment 1. (A) is a disassembled perspective view of Embodiment 2, (b) is sectional drawing of the circuit block used for Embodiment 2. FIG. It is explanatory drawing of the manufacturing process of the circuit block used for Embodiment 3. FIG. (A) is a perspective view of the circuit block used for Embodiment 4, (b)-(d) is a mounting process explanatory drawing to the stem of the circuit block used for Embodiment 4. FIG. It is a circuit block diagram of an infrared detector. (A) is sectional drawing of a prior art example, (b) is an exploded perspective view at the time of actual use of a prior art example. (A) is an exploded perspective view of a three-dimensional circuit block of another conventional example, (b) is a perspective view with a cap of another conventional example removed, and (c) is a perspective view of another conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stem 2 Cap 3 Circuit block 4 Infrared passage window 5 Optical filter 6 Spacer 7 Circuit board 8 Second resin layer body 9 Substrate 10 First resin layer body 11 Recess 12 Land 13 Circuit pattern 16 IC
17 Electronic component 19 Connection pin A Infrared detector X Pyroelectric element

Claims (12)

An infrared detector that houses a circuit block on which an infrared detection element, an electronic component, and an IC are mounted inside a package container,
The circuit block has a concave and convex portion integrally formed on the upper surface of the resin layer, and a support receiving portion that supports both sides of the infrared detection element at a convex portion, and a recess for the heat insulating layer below the infrared detection element. The electronic circuit elements such as ICs and electronic components mounted on the first substrate on which the wiring patterns constituting the circuit portions are formed are placed in the resin layer below the concavo-convex shape portions. An infrared detector characterized by being embedded in one piece. The infrared detector according to claim 1, wherein the resin layer is a resin layer obtained by curing a thermosetting resin mixed with an inorganic filler. The resin layer is composed of a first resin layer having the concavo-convex shape portion formed on the upper surface and the second resin layer in which the electronic circuit element is integrally embedded, and a specific potential is provided between the first and second resin layers. 3. The infrared detector according to claim 1, further comprising a shield layer having a ground potential. The infrared detector according to claim 3, wherein the shield layer is formed on a second substrate made of a thermosetting resin. The second substrate is made of a thermosetting resin, and the first resin layer, the second resin layer, and the electronic circuit element incorporated in the second resin layer are mounted on the first substrate. When the circuit block is formed by heating and pressing the substrate, the substrate is disposed between the first and second resin layers and integrated with the first and second resin layers by the heating press. The infrared detector according to claim 4. 4. The infrared detector according to claim 3, wherein the shield layer is formed of a copper foil layer formed on an upper surface of the second resin layer. The copper foil layer was integrated on the second resin layer when the first substrate was integrated by a heat press so that the electronic circuit element was incorporated in the second resin layer. And interposing between the first resin layer and the second resin layer when forming the circuit block by integrating the first resin layer on the second resin layer by a hot press. The infrared detector according to claim 6. A circuit pattern that connects the infrared detection element, the shield layer, and the electronic circuit element embedded in the second resin layer is a through-hole formed of a through-hole that penetrates the first and second resin layers. The infrared detector according to claim 2, wherein the infrared detector is joined. 9. The infrared detector according to claim 1, wherein the electronic circuit element embedded in the resin layer is only an IC. The infrared detector according to claim 1, wherein the electronic circuit element embedded in the resin layer is only a chip-shaped electronic component. The container includes a table and a cap attached to the table. The circuit block is mounted on the upper surface of the table via a spacer, and a land formed on the lower surface of the circuit block. The infrared detector according to claim 1, wherein an upper end of a terminal pin protruding from the upper surface of the instrument base is electrically joined. The spacer is provided with an insertion portion for passing the terminal pin portion positioned between the terminal pin and the joint portion of the circuit block in the vertical direction with an opening on the outer peripheral surface of the spacer. The infrared detector according to claim 11.

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