JP2007227718A - Electronic component having resistive element and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to suppress peeling of a heat radiating member and to sufficiently form a low melting point metal film such as solder on the surface of the heat radiating member. <P>SOLUTION: An electronic component has a resistive element having surface terminal electrodes 3A to be paired provided on end side regions of an insulating substrate 2, and a resistor 4 arranged on one surface of the insulating substrate 2 and connected to both the surface terminal electrodes 3A; and a heat radiating member 9 arranged on the other surface of the insulating substrate 2 so as not to contact the terminal electrodes 3 and used for heat radiation of the resistive element. The heat radiating member 9 has end face reaching portions 9A1, 9A2 (end face contacting portions) extending up to a second end face 2B which is different from two first end faces 2A of the insulating substrate 2 opposite to an arrangement direction of the terminal electrodes 3 and is arranged to connect the two first end faces 2A; and an end face non-reaching portion 9B (end face non-contacting portion) having a distance between itself and the second end face 2B without extending. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic component having a resistance element and a method for manufacturing the same.

When the resistance element is energized, Joule heat is generated. If this heat is excessively generated, desired resistance element characteristics may not be obtained. In view of this, a heat dissipation technique for releasing this heat to the mounting circuit board has been proposed. In the technique, as shown in FIG. 7, the electronic component that becomes the resistor 21 has an insulating substrate 22, and faces the circuit board (not shown) in a mounted state (FIGS. 7A and 7B). (C) The heat radiating member 23 is formed on the lower surface of (D), and the circuit board and the heat radiating member 23 are connected (see Patent Documents 1 and 2).
Japanese Utility Model Publication No. 64-6006 JP-A-2-317824

  FIG. 7A shows a cross-sectional view of the resistor 21. An example of the mounting surface (back surface) of the resistor 21 is shown in FIGS. 7E and 7F. When the heat dissipating member 23 is in contact with the edge of the insulating substrate 22 as shown in FIG. 7E, the heat dissipating member straddles the dividing grooves of the large insulating substrate in which the dividing grooves are formed vertically and horizontally in order to improve mass productivity. Then, when the large insulating substrate is divided into individual resistors 21 by applying stress so as to open the dividing grooves, the heat radiating member 23 is easily peeled off at the end portion 22a.

  The structure in FIG. 7F can prevent the peeling. However, with this configuration, when solder is applied to the surface of the terminal electrode 24 and the surface of the heat dissipation member 23 by barrel plating in order to improve mass productivity, the end surface 23a of the heat dissipation member 23 is the end portion of the insulating substrate 22. Since it does not extend to 22a, it is difficult for the dummy ball (electrode for plating) to contact. For this reason, solder hardly adheres to the surface of the heat dissipation member 23.

  FIG. 7B shows a cross-sectional view of another resistor 21A, and FIG. 7G shows an example of a mounting surface of the resistor 21A. Thus, if the terminal electrode 24 and the heat radiating member 23 are integrated, the solder can be sufficiently applied to the surface of the heat radiating member 23. However, since the areas of the left and right terminal electrodes 24 are too different, there is a difference in the surface tension of the molten solder when the resistor 21A is to be surface-mounted on the circuit board. The solder responsible for adhering to the board may melt.

  FIG. 7C shows a cross-sectional view of still another resistor 21B, and FIG. 7H shows an example of a mounting surface of the resistor 21B. FIG. 7D shows a cross-sectional view of still another resistor 21C, and FIG. 7I shows an example of a mounting surface of the resistor 21C. When these structures are employed, it is possible to suppress melting of the solder when attempting to mount on the surface. However, since the heat radiating member 23 is not disposed in at least the region facing the maximum heat generating region of the resistors 21B and 21C via the insulating substrate 22, it is difficult to obtain a sufficient heat radiating effect. For example, when the resistor 25 is formed of a thick film, a thin film, a metal plate, or the like and undergoes a process of forming a trimming groove for adjusting the resistance value, the maximum heat generation region of the resistor 21 is an end portion of the trimming groove. The terminal end can not be predicted or be previously any position. Therefore, as in the configurations of FIGS. 7H and 7I, a configuration in which there is a possibility that there is a portion where the heat dissipation member 23 is not disposed in a region facing the resistor 25 with the insulating substrate 22 interposed therebetween. In some cases, it is difficult to obtain a sufficient heat dissipation effect.

  Therefore, the problem to be solved by the present invention is that an electronic component having a resistance element that can suppress peeling of the heat dissipation member and can sufficiently form a low melting point metal film such as solder on the surface of the heat dissipation member, and a manufacturing method thereof Is to provide.

  In order to solve the above problems, an electronic component having a resistance element according to the present invention is disposed on one surface of a pair of terminal electrodes and an insulating substrate provided in an edge region of the insulating substrate, and is connected to both of the terminal electrodes. And a heat radiating member for radiating heat of the resistance element, which is disposed so as not to contact the terminal electrode on the other surface of the insulating substrate, and the heat radiating member is disposed on the terminal electrode. An end surface reaching portion (end surface) that is a second end surface that is different from the two first end surfaces of the insulating substrate facing in the direction, and extends to the second end surface that is arranged so as to connect the two first end surfaces Contact portion) and an end surface non-reaching portion (end surface non-contact portion) that is not stretched and is provided with a distance from the second end surface.

  According to the present invention, even when the second end face is exposed when the large insulating substrate is divided and a part of the heat dissipation member is broken during the division, the end face non-reaching portion is between the second end face. Since it has a distance, it does not break when dividing. In that case, peeling of the heat dissipation member can be suppressed. Moreover, since the extension part used as a part of heat radiating member is extended to the 2nd end surface, the cross section of the thickness direction of a heat radiating member is exposed to the 2nd end surface. Therefore, when barrel plating is performed, the probability of contact with the dummy ball is increased, and a low melting point metal film such as solder can be sufficiently formed on the surface of the heat dissipation member. In addition, even when the insulating substrate is formed without dividing the large insulating substrate, there is a tendency that the heat radiating member is peeled off from the portion exposed at the second end face during barrel plating or the like. In this configuration, peeling is unlikely to occur even in such a case.

  In another invention, in addition to the invention of the electronic component having the above-described resistance element, the insulating substrate is a rectangular parallelepiped, has two second end faces facing each other, and the heat dissipation member has both of the two second end faces. It has an end face reaching portion extended to. By adopting this configuration, the cross section in the thickness direction of the heat radiating member is exposed at the two second end faces which are both ends of the rectangular parallelepiped. Therefore, when barrel plating is performed, the probability of contact with the dummy ball is further increased, and a low melting point metal film such as solder on the surface of the heat dissipation member can be sufficiently formed.

  In another aspect of the invention, in addition to the invention of the electronic component having the above-described resistance element, the end surface side portion of the heat dissipation member extending to the second end surface includes a first end surface reaching portion extended to the second end surface, An end face non-reaching portion that is not stretched and has a distance between the second end face and a first end face reaching portion that is extended to the second end face are arranged in this order along the second end face. . By adopting this configuration, the cross section in the thickness direction of the heat radiating member can be exposed over a wide range on the second end surface. Therefore, when barrel plating is performed, the probability of contact with the dummy ball is increased, and a low melting point metal film such as solder can be sufficiently formed on the surface of the heat dissipation member. Furthermore, since the end surface reaching portion is divided into two extension portions (first and second extension portions), the individual fracture surface of the heat dissipation member at the time of division becomes small, and each can be broken with a small force. . Therefore, even if a force in a direction causing separation from the insulating substrate surface is generated at the time of breaking, it is considered that the breaking is easily completed before peeling.

  In another aspect of the invention, in addition to the invention of the electronic component having the above-described resistance element, the heat dissipation member is a straight line in a direction along the second end face, and is symmetric with respect to a straight line passing through the central region of the other face of the insulating substrate. It has a line-symmetric shape about the axis. By adopting this configuration, the self-alignment effect is not adversely affected even after a so-called reflow process in which the heat dissipation member is connected to the mounting circuit board by solder. Here, the self-alignment means that the electronic component moves to an accurate position on the pattern of the mounting board by the surface tension of the solder.

  In order to solve the above problems, a method for manufacturing an electronic component having a resistance element according to the present invention includes a unit of a large-sized insulating substrate having a linear divided portion that intersects a surface vertically and horizontally and surrounded by the linear divided portion. A step (hereinafter referred to as a first step) of forming one or a plurality of circuit elements including at least a resistive element on each of the insulating substrates (hereinafter referred to as unit insulating substrates), and conductivity for heat dissipation of the resistive elements. The heat radiation member is formed so as to have a portion straddling the linear divided portion and a portion not straddling so as not to conduct with the resistance element (hereinafter referred to as a second step), and a first step. And a step of dividing the large insulating substrate into individual unit insulating substrates along the linear dividing portion after the second step (hereinafter, referred to as a third step), and then contacting the resistance element to connect the terminals. Table of surface of terminal electrode and heat dissipation member The step of depositing a low-melting metal film by a barrel plating method, and a (hereinafter. Referred to as a fourth step).

  According to this invention, a part of the heat radiating member has a portion that does not break when dividing the large insulating substrate (a portion that does not straddle the linear divided portion). Therefore, peeling of the heat dissipation member at the time of division can be suppressed. In addition, since a part of the heat radiating member has a portion that breaks when the large insulating substrate is divided (a portion that straddles the linear divided portion), a cross section in the thickness direction of the heat radiating member is formed on the end surface of the unit insulating substrate. It will be exposed. Therefore, when barrel plating is performed, the probability of contact with the dummy ball is increased, and a low melting point metal film such as solder can be sufficiently formed on the surface of the heat dissipation member.

  In another invention, in addition to the invention of the method for manufacturing an electronic component having a resistance element as described above, in the fourth step, the thicknesses of the low melting point metal films deposited on the surface of the terminal electrode and the surface of the heat dissipation member are both 3 μm or more and 12 μm or less. By setting the thickness of the low melting point metal film to 3 μm or more, sufficient solder wettability can be secured. Further, by setting the thickness of the low melting point metal film to 12 μm or less, it is possible to reduce the influence on the external dimension accuracy of a general electronic component without excessive deposition of the low melting point metal.

  According to the present invention, an electronic component having a resistance element that can suppress peeling of a heat dissipation member even by dividing a large insulating substrate and can sufficiently form a low melting point metal film such as solder on the surface of the heat dissipation member, and a method for manufacturing the same can do.

  FIG. 1A is a cross-sectional view of a surface-mounted resistor 1, which is an example of an electronic component having a resistive element according to an embodiment of the present invention. FIG. FIG. 2 shows a mounting surface (rear surface) in which the nickel plating layer 7 and the tin plating layer 8 shown in FIG. 1A are omitted. The resistor 1 is an insulating substrate provided in a rectangular parallelepiped insulating substrate 2, a pair of surface terminal electrodes 3A provided in an edge region of one surface of the insulating substrate 2, and facing the arrangement direction of the surface terminal electrodes 3A. A pair of end surface terminal electrodes 3B formed on the surfaces of the two first end surfaces 2A of the substrate 2 and an end region of the other surface of the insulating substrate 2 (opposing the surface terminal electrodes 3A through the insulating substrate 2) A pair of back surface terminal electrodes 3C provided at a position). The surface terminal electrode 3A and the end surface terminal electrode 3B, and the end surface terminal electrode 3B and the back surface terminal electrode 3C are electrically connected, and the surface terminal electrode 3A, the end surface terminal electrode 3B, and the back surface terminal electrode 3C are integrated. The terminal electrode 3 is configured. The terminal electrodes 3 are formed so as to cover the respective first end faces 2A, and the paired terminal electrodes 3 are formed.

  The resistor 1 has a resistor 4 connected to both the pair of surface terminal electrodes 3 </ b> A, and the resistor 4 and the terminal electrode 3 form a resistance element. The resistor 4 is covered with a first glass film 5, and the first glass film 5 is further covered with a second glass film 6. The pair of terminal electrodes 3 is covered with a nickel plating layer 7, and the nickel plating layer 7 is covered with a tin plating layer 8 serving as a low melting point metal layer.

  Further, as shown in FIG. 1B, the resistor 1 is disposed on the other surface (back surface) of the insulating substrate 2 so as not to come into contact with the terminal electrode 3, and generates Joule heat generated by the resistance element. It has a heat dissipating member 9 to be moved. The heat dissipating member 9 is an end face different from the two first end faces 2A (the end face on which the end face terminal electrode 3B is formed) provided to face the arrangement direction of the terminal electrode 3, and the first end face 2A is End face non-reaching provided with a distance between the end face reaching portion 9A (first end face reaching section 9A1, second end face reaching section 9A2) extended to the second end face 2B to be connected and the second end face 2B without being stretched Part 9B. The heat radiating member 9 is covered with a nickel plating layer 7 similarly to the terminal electrode 3, and the nickel plating layer 7 is covered with a tin plating layer 8.

  FIG. 2 shows a state in which the resistor 1 is mounted on the mounting circuit board 10. Most of the Joule heat generated by the resistance element in the resistor 1 passes through the insulating substrate 2, the heat dissipation member 9, the nickel plating layer 7 covering the heat dissipation member 9, and the tin plating layer 8 covering the nickel plating layer 7, It moves to the land 16 and the mounting circuit board 10 via the solder 11 in contact with the tin plating layer. Therefore, even if Joule heat is excessively generated, most of the Joule heat can be released to the mounting circuit board 10, so that desired resistance element characteristics can be maintained. Further, by disposing the heat dissipating member 9 so as not to contact both of the paired terminal electrodes 3, a large difference occurs in the surface tension of both solders 11 at the time of melting that contacts the paired terminal electrodes 3. This makes it difficult to cause a situation such as melting of the molten solder during the reflow process.

  Here, the heat dissipating member 9 provided on the other surface of the insulating substrate 2 has two opposing second end surfaces connecting the first end surface 2A (the end surface terminal electrode 3B is formed) facing each other as a pair. 2B, and an end surface reaching portion 9A that extends to both sides, and an end surface non-reaching portion 9B that is not stretched and is spaced from the second end surface. The heat radiating member 9 on the second end face 2B side has a first end face reaching portion 9A1, an end face non-reaching portion 9B, and a second end face reaching portion 9A2 arranged in this order, and a plan view (FIG. 1B )), The appearance is H-shaped. Therefore, when dividing the large insulating substrate into individual unit insulating substrates (insulating substrate 2), the second end face 2B is exposed, and a part of the heat radiating member 9 is broken during the division, Even when the end face reaching portion 9A is formed, the end face non-reaching portion 9B has a distance from the second end face 2B and therefore does not break during the division. For this reason, the fixing force of the unbroken portion to the other surface of the insulating substrate 2 does not receive much impact due to the breakage, and therefore the peeling of the heat radiation member 9 from the other surface of the insulating substrate 2 can be suppressed.

  On the other hand, the fracture surface of the heat dissipation member 9 at the time of division is exposed at the second end face 2B. Therefore, when barrel plating is performed, the probability that the heat radiating member 9 and the dummy ball are in contact with each other increases, and a low melting point metal film such as solder on the surface of the heat radiating member 9 can be sufficiently formed. Moreover, since the heat radiating member 9 has the torn surface in the four corners of the H-shaped shape, the torn surface is exposed over a wide range. Furthermore, since the end surface reaching portion 9A is divided into two extending portions (first and second end surface reaching portions 9A1, 9A2), the individual fracture surfaces of the heat radiation member 9 at the time of division become small, and each of them has a small force. Can be broken. Therefore, even if a force in a direction causing separation from the surface of the insulating substrate 2 is generated at the time of breaking, it is considered that the breaking is easily completed before peeling.

  The H-shaped shape of the heat radiating member 9 is such that the heat radiating member 9 is a line in the direction along the second end surface 2B, and a straight line L passing through the central region of the other surface of the insulating substrate 2 is a symmetry axis. It has a line-symmetric shape. Here, the maximum heat generation region of the resistance element is usually the narrowest portion of the current flow path of the resistor 4 constituting the resistance element. When the resistor 4 is formed of a thick film, a thin film, or a metal plate, a process of forming a trimming groove for adjusting a resistance value is often performed. When this step is performed, the maximum heat generation region of the resistance element becomes the end portion of the trimming groove. The terminal end can not be predicted or be previously any position. However, the trimming groove is usually formed in a direction perpendicular to the current flow path of the resistor 4 and from the end of the resistor 4 toward the center, that is, to narrow the current flow path. Therefore, the heat radiating member 9 shown in FIG. 1B is formed so as to face at least the intermediate region of the resistor 4 with the insulating substrate 2 interposed therebetween and to cover the other surface of the insulating substrate 2 in general. Therefore, the heat radiating member 9 exists in the opposing part through the insulating substrate 2 of the maximum heat generating area of the resistance element. Therefore, most of the Joule heat can be transferred to the mounting circuit board 10 through the heat radiating member 9.

  Further, the heat dissipating member 9 has a line-symmetrical H shape that is a line in the direction along the second end surface 2B and that has a straight line L passing through the central region of the other surface of the insulating substrate 2 as an axis of symmetry. As a result, when the heat radiating member 9 is connected to the mounting circuit board 10 by the solder 11, the surface tension of the solder 11 is not biased through a so-called reflow process. Therefore, the effect of so-called self-alignment, in which the resistor 1 serving as an electronic component moves to an accurate position on the pattern (land 16) of the mounted circuit board 10, is not impaired.

  FIG. 3 shows an example of a method for manufacturing an electronic component (here, resistor 1) having the resistance element according to the embodiment of the present invention. Hereinafter, the process of manufacturing the resistor 1 will be described in order with reference to the drawings.

  FIG. 3A shows a large insulating substrate 12 made of alumina. One surface of the large insulating substrate 12 has a linear dividing groove 13 that intersects the surface vertically and horizontally. FIG. 3B is a diagram illustrating the formation of the back surface terminal electrode 3 </ b> C and the heat dissipation member 9. In FIG. 3B, a metal glaze type conductive paste containing Ag as a main constituent material is arranged at a predetermined position on the surface opposite to one surface (the other surface) of the large insulating substrate 12 by screen printing. It shows the state that was made to. One of the predetermined positions is divided along the dividing groove 13 in a later step to form a unit insulating substrate (insulating substrate 2), which is a surface opposite to one surface of the insulating substrate 2 ( This is a position to be a pair of back surface terminal electrodes 3C provided in the edge region of the other surface. From the viewpoint of enlarging the pattern at the time of screen printing and facilitating pattern design and stabilizing the printing accuracy, the edge region of the adjacent insulating substrate 2 is divided into one surface of the large insulating substrate 12. Adjacent backside terminal electrodes 3 </ b> C straddling the groove 13 are integrally formed. Part of the first step is completed by the formation of the back terminal electrode 3C.

  The large insulating substrate 12 has another portion at a predetermined position that has a portion that straddles the dividing groove 13 on one surface of the large insulating substrate 12 and a portion that does not straddle so as not to be electrically connected to the back surface terminal electrode 3C. It is the arrangement position of the heat radiating member 9 formed in the other surface of the. In disposing the heat dissipating member 9, the heat dissipating member 9 is integrally formed over the adjacent insulating substrates 2 from the viewpoint of enlarging the pattern at the time of screen printing and facilitating pattern design and stabilizing the printing accuracy. Forming. After this screen printing process, the large insulating substrate 12 is baked to solidify the back terminal electrode 3C and the heat dissipation member 9. The formation of the heat dissipating member 9 completes the second step.

FIG. 3C is a diagram illustrating the formation of the front surface terminal electrode 3 </ b> A performed after the formation of the back surface terminal electrode 3 </ b> C and the heat dissipation member 9. FIG. 3C shows a state in which a metal glaze-based conductive paste mainly composed of an Ag—Pd-based alloy is disposed at a predetermined position on one surface of the large insulating substrate 12 by screen printing. . This predetermined position refers to a pair provided in the edge region of one surface of the insulating substrate 2 when the unit insulating substrate (insulating substrate 2) is divided along the dividing groove 13 in a later step. This is the position to be the surface terminal electrode 3A.

  Here, from the viewpoint of facilitating pattern design by enlarging the pattern during screen printing and stabilizing the printing accuracy, the edge region of the adjacent insulating substrate 2 straddles the dividing groove 13. Adjacent surface terminal electrodes 3A are integrally formed. However, this integral formation only brings the adjacent resistance elements into a state of being connected in series, and does not mean that the adjacent resistance elements are connected in parallel. This is because the trimming process for adjusting the resistance value described later is performed accurately. After this screen printing step, the large insulating substrate 12 is baked to solidify the surface terminal electrode 3A. Thus, a part of the first process is completed.

  In FIG. 3D, after the state of FIG. 3C, a metal glaze-based resistor paste containing ruthenium oxide as a main constituent material is placed in a predetermined position on one surface of the large insulating substrate 12 by screen printing. The state of arrangement is shown. The predetermined position is a pair of the edge regions of one surface of the insulating substrate 2 when the unit substrate (insulating substrate 2) is divided along the dividing groove 13 in a later step. This is a position that partially overlaps both of the surface terminal electrodes 3A previously formed and is a portion that becomes the resistor 4. After this screen printing step, the resistor 4 is obtained by baking and solidifying the large insulating substrate 12. At this stage, a resistance element composed of the resistor 4 connected to both of the paired surface terminal electrodes 3A is obtained. This completes the first step.

  FIG. 3E shows a state in which the first glass film 5 is provided thereafter. In FIG. 3 (E), the portion where the first glass film 5 and the resistor 4 overlap is shown with the resistor 4 and the first glass film 5 is not shown. When the first glass film 5 is provided, first, a glass paste is placed on one surface of the large insulating substrate 12 at a position covering the resistor 4 previously formed by screen printing. After this screen printing step, the large insulating substrate 12 is fired to obtain the first glass film 5. FIG. 3F shows a state in which the trimming groove 14 is formed in the resistor 4 by laser irradiation for adjusting the resistance value of the resistance element. The first glass film 5 previously formed functions to prevent excessive destruction of the resistor 4 due to this laser irradiation. In FIG. 2G, glass paste is then placed on one surface of the large insulating substrate 12 at a position covering the first glass film 5 previously formed by screen printing, and after this screen printing process, The state which the 2nd glass membrane | film | coat 6 was obtained by baking the insulated substrate 12 is shown. The second glass film 6 functions to protect the entire resistance element by solidifying in the state of entering the trimming groove 14.

  FIG. 3 (H) is divided along the dividing groove 13 that will be the first end face 2A described above, among the dividing grooves 13 formed vertically and horizontally on one surface of the large insulating substrate 12. Shows the state. In this division, the large insulating substrate 12 is bent in the direction of opening the dividing groove 13 and divided into strip-like insulating substrates 15 (hereinafter referred to as primary division). At the time of primary division, the front surface terminal electrode 3A and the back surface terminal electrode 3C formed over the division groove 13 are simultaneously broken along the division groove 13 and the first end surface 2A is broken. The cross section is exposed. Here, it is considered that the back surface terminal electrode 3 </ b> C and the surface terminal electrode 3 </ b> A formed on the other surface (back surface) of the large insulating substrate 12 may be separated from the insulating substrate 2 by the primary division. However, even if the peeling occurs, the back terminal electrode 3C and the surface terminal electrode 3A are peeled from the strip-shaped insulating substrate 15 in the step of depositing silver (Ag) on the first end face 2A described later by the sputtering method. Since Ag is also deposited on the part that has been removed, it can function as the resistor 1.

  FIG. 3I shows a state in which the end face terminal electrode 3B is formed by subsequently depositing Ag on the first end face 2A by the sputtering method. At this time, Ag is also deposited on the fracture surfaces of the surface terminal electrode 3A and the back surface terminal electrode 3C, so that the surface terminal electrode 3A and the end surface terminal electrode 3B, and the end surface terminal electrode 3B and the back surface terminal electrode 3C are electrically connected. The terminal electrode 3 is formed by connecting the surface terminal electrode 3A, the end surface terminal electrode 3B, and the back surface terminal electrode 3C together.

  FIG. 3J shows a state in which the strip-shaped insulating substrate 15 is subsequently divided along the dividing grooves 13 that form the second end face 2B. In this division, stress is applied in the direction in which the dividing grooves 13 are opened to divide the unit insulating substrate (insulating substrate 2) (hereinafter referred to as secondary division). The left side of FIG. 3 (J) shows one surface (front surface) of the resistor 1, and the right side of FIG. 3 shows the other surface (back surface) of the resistor 1. At the time of secondary division, the portion of the heat dissipation member 9 that has been partially straddled across the dividing groove 13 and the portion that straddles the dividing groove 13 and the portion of the back terminal electrode 3C that straddles the dividing groove 13 are divided. It breaks simultaneously along the groove 13 and those fracture surfaces are exposed at the second end face 2B. The third step is completed by the primary division and the secondary division. Here, it is considered that the back surface terminal electrode 3 </ b> C formed on the other surface (back surface) of the large insulating substrate 12 may be peeled off from the insulating substrate 2 by the secondary division. However, since the area of the fracture surface at the time of the secondary division of the back terminal electrode 3C is usually small, it easily breaks. And since the impact at the time of the fracture | rupture is small, the back surface terminal electrode 3C hardly reaches peeling with the insulating substrate 2 surface.

  Thereafter, the nickel plating layer 7 is formed on the surface of the surface terminal electrode 3A, the end surface terminal electrode 3B and the back surface terminal electrode 3C, and the surface of the heat dissipation member 9 by barrel plating, and the tin plating layer 8 is further formed on the surface of the nickel plating layer 7. Form. The nickel plating layer 7 functions to prevent so-called solder erosion of the terminal electrode 3 due to alloying of the terminal electrode 3 and the tin plating layer 8. In addition, the tin plating layer 8 functions so as to improve the wettability with the solder serving as the fixing member during surface mounting on the mounting circuit board 10. Here, the plating time and / or the energization current value and the like are adjusted so that the thicknesses of the nickel plating layer 7 and the tin plating layer 8 are 3 μm or more and 12 μm or less. The fourth step is completed by forming the plating layer by the barrel plating method.

  For the resistor 1 (see FIG. 1) manufactured through the above steps and the resistor 21 shown in FIG. 7 (F), a comparative study was performed with the number of samples n = 20. The two resistors 1 and 21 are manufactured under the same conditions except that the resistor 21 has a rectangular shape of the heat dissipating member 23a and does not reach the end face of the insulating substrate 22a. 4A shows the result of comparing the thickness of the nickel plating layer 7 and FIG. 4B shows the result of comparing the thickness of the tin plating layer 8. The plating conditions (plating time and / or energization current value, etc.) of the conventional resistor 21 are the same as the plating conditions of the resistor 1 according to the present embodiment. The thickness (maximum value 8.3 μm, minimum value 5.7 μm, average value 6.9 μm) of the nickel plating layer 7 deposited on the surface of the heat dissipation member 9 according to the present embodiment and the thickness (maximum value) of the tin plating layer 8. 7.2 μm, minimum value 4.7 μm, average value 6.1 μm) is clearly the thickness of the nickel plating layer deposited on the surface of the conventional heat radiating member 23a (maximum value 6.9 μm, minimum value 2.4 μm, average) Value 4.2 μm) and the thickness of the tin plating layer (maximum value 1.7 μm, minimum value 0.6 μm, average value 1.3 μm). From this, by exposing a part of the heat radiating member 9 according to the present embodiment to the second end surface 2B of the insulating substrate 2, the effect of making the dummy balls easily come into contact with the heat radiating member 9 is significantly obtained. You can see that

  Next, with respect to the resistor manufactured under the same conditions as the resistor 1 except that the resistor 1 according to the present embodiment, the above-described conventional resistor 21 and the heat dissipating member 9 are not provided, the temperature at the number of samples n = 20 An impact test was performed. In the temperature impact test, these three types of resistors are mounted on a mounting circuit board made of an epoxy resin plate-like product mixed with glass fiber, measured for resistance at room temperature, and then heated to 125 ° C. In this test, the temperature was lowered to -55 ° C in 30 minutes and raised to 125 ° C in 30 minutes 1000 times, and then the resistance value was measured again at room temperature to obtain the rate of change from the initial resistance value. is there.

  FIG. 5 shows the test results. The resistance value change rate (maximum value 0.37%, minimum value 0.13%, average value 0.25%) of the resistor 1 according to the present embodiment is the same as that of the resistor 1 except that the heat radiating member 9 is not provided. The resistance value change rate (maximum value 0.84%, minimum value 0.44%, average value 0.60%) of resistors manufactured under the same conditions is clearly smaller, and the resistance element characteristics are also improved by thermal shock. You can see that it is maintained. Further, the resistance value change rate of the resistor 1 according to the present embodiment is the resistance value change rate of the above-described conventional resistor 21 (maximum value 0.61%, minimum value 0.24%, average value 0.36%). Smaller than). This is because the thickness of the plating layer deposited on the surface of the heat dissipating member 23a of the conventional resistor 21 described above causes a difference from the resistor 1 according to the present embodiment in a state of being fixed to the mounting circuit board. Therefore, it is considered that the difference becomes a factor for inhibiting heat transfer from the conventional resistor 21 to the mounting circuit board.

  Although the resistor 1 and the manufacturing method thereof have been described above, various modifications can be made without departing from the gist of the present invention. For example, although the front surface terminal electrode 3A, the back surface terminal electrode 3C, and the resistor 4 are formed of a thick film by a screen printing method, all or a part of them may be formed of a thin film by a sputtering method or the like. Moreover, although the back surface terminal electrode 3C and the heat radiating member 9 may be formed simultaneously, you may form separately. Moreover, you may perform the process of forming 3 A of surface terminal electrodes shown in FIG.3 (C) before the process of forming the back surface terminal electrode 3C and the thermal radiation member 9 shown in FIG.3 (B). However, when the large insulating substrate 12 is placed on a metal transport belt or the like during firing, metal rust on the surface of the transport belt adheres to the surface terminal electrode 3A and contacts with the resistor 4 to be formed later. In order to prevent the state from becoming unstable, the step of forming the back surface terminal electrode 3C and the heat dissipation member 9 is preferably performed before the step of forming the surface terminal electrode 3A as in the present embodiment. Furthermore, the end face terminal electrode 3B can be formed by a method other than the sputtering method, for example, a coating method, a screen printing method, or the like. Furthermore, in the above-described embodiment, the second step (the step of forming the heat radiating member 9) is performed during the first step (the step of forming the resistance element), but the second step is the first step. You may perform before the start of this process, or after completion. Furthermore, the back terminal electrode 3C and the heat radiating member 9 can be configured by firing a metal glaze paste such as an Ag—Pd alloy as a migration suppressing material. By doing so, even if the distance between the back terminal electrode 3C and the heat radiating member 9 is relatively short like the resistor 1 of this example, a short circuit due to migration between the pair of back terminal electrodes 3C can be suppressed.

  Moreover, although the resistor 1 which concerns on this Embodiment has the back surface terminal electrode 3C, it is not necessarily required. For example, in the mounted resistor 1 in FIG. 2, the back surface terminal electrode 3 </ b> C can be eliminated, and the front surface terminal electrode 3 </ b> A and the end surface terminal electrode 3 </ b> B can be fixed to the land 16 with the solder 11. Moreover, although the tin-plating layer 8 is used for the low melting-point metal layer provided in the resistor 1 which is an electronic component having the resistance element according to the present embodiment, a solder plating layer is used instead of the tin-plating layer 8. can do. Here, the “solder” includes so-called lead-free solder such as Pb—Sn alloy and Sn—Cu alloy.

  In addition, the resistor 1 as an electronic component having the resistance element according to the embodiment of the present invention is a surface-mount type chip resistor including one resistance element. However, the present invention can also be applied to other electronic components such as multiple chip resistors and chip network resistors having a plurality of resistance elements on a unit insulating substrate. Since this composite electronic component generates a greater amount of Joule heat than the resistor 1 consisting of one resistive element and Joule heat is likely to accumulate on the insulating substrate, there is a high need to release Joule heat from the insulating substrate. In such a case, it is very preferable to provide the heat dissipating member 9 like the resistor 1 according to the present embodiment. Further, the heat radiating member 9 can be provided also in a composite electronic component including a resistance element and another circuit element such as a capacitor.

  The electronic component having the resistance element according to the embodiment of the present invention can exhibit an advantage particularly when used in an environment where the ambient temperature tends to be high. For example, for use in electronic equipment with high-density mounting, for personal computers, etc., for electronic equipment in which a resistor is mounted near a CPU (Central Processing Unit) that tends to be hot, and in a car engine room that is likely to be hot The use to the electronic control part etc. of the inside is suitable.

  An electronic component having a resistance element according to an embodiment of the present invention uses an insulating substrate 2 made of alumina. However, in order to improve heat dissipation, it is preferable to adopt a material having good thermal conductivity such as aluminum nitride.

  In the third step of manufacturing the electronic component having the resistance element according to the embodiment of the present invention, the large insulating substrate 12 and the strip-shaped insulating substrate 15 are divided by applying stress in the direction of opening the dividing grooves 13. Realized by the method. However, instead of this method, other dividing means such as dicing can be employed. The advantage of adopting dicing is that the dimensional accuracy of the division can be improved, and the portion of the heat radiation member 9 formed across the division line (including both visible and invisible) is cut. In doing so, the impact applied to the portion is relatively small, and peeling from the insulating substrate 2 can be further suppressed. In general, it is possible to adopt a method in which dicing is generally used for primary division, which is difficult to divide with high insulation substrate dimensional accuracy, and stress is applied to the secondary division in the direction of opening the dividing groove 13 that is advantageous in terms of manufacturing cost. .

  When manufacturing an electronic component having a resistance element according to an embodiment of the present invention, the dividing groove 13 can be formed on the other surface of the large insulating substrate 12 (surface on which the heat dissipation member 9 is disposed). In the third step, if the large insulating substrate 12 and the strip-shaped insulating substrate 15 are divided in the direction of opening the dividing grooves 13, the end surface reaching portion 9A of the heat radiating member 9 becomes the surface of the insulating substrate 2 ( It is difficult to apply force in the direction of peeling from the other surface), and the effect of suppressing peeling from the surface of the insulating substrate 2 of the heat radiating member 9 can be greatly obtained. In order to obtain the same effect, the dividing groove for primary division is formed on one surface of the large insulating substrate 12 (surface on which the heat dissipation member 9 is not disposed), and the dividing groove for secondary division is formed on the large insulating substrate. The method of forming on the other surface of 12 (surface on which the heat dissipation member 9 is disposed) can be employed.

  In the electronic component having the resistance element according to the embodiment of the present invention, the heat radiating member 9 is made of a conductive material in the same manner as the material of the terminal electrode 3. When the heat transfer between the electronic component and the mounting circuit board 10 is performed via a low melting point metal (solder), it is suitable that the heat radiating member 9 is a conductive material. However, when there is no heat transfer inclusion between the electronic component and the mounted circuit board 10, the heat dissipating member 9 can be made of an insulator such as a commercially available heat dissipating silicon gel. By using an insulator such as a heat dissipating silicon gel, a surface mount type in which a resistor not using the insulating substrate 2, such as a nichrome plate (Ni-Cr alloy plate), is resin-molded using an epoxy resin or a liquid crystal polymer. Heat transfer from the mold part to the mounting circuit board surface can be realized. In addition, even if the resistor is a metal plate resistor and the resistor is not molded, an insulator such as a heat-dissipating silicon gel is brought into direct contact with the resistor and connected to the mounting circuit board so that the joule of the metal plate resistor can be connected. Heat can be transferred to the mounting circuit board.

  FIG. 6 shows various modifications of the shape of the heat dissipation member 9 according to the embodiment of the present invention. FIG. 6 (A) is obtained by halving the end surface reaching portion 9A of the heat radiating member 9 of the resistor 1 shown in FIG. The heat radiating member 9C is preferably adopted when the heat radiating member 9 is likely to be peeled off from the insulating substrate 2 by secondary division.

  6B shows the width of the end surface reaching portion 9A of the heat radiating member 9 of the resistor 1 shown in FIG. 1, that is, the distance of the portion exposed at the second end surface 2B, about 1. It is 5 times. The heat dissipating member 9D is preferably adopted when it is desired to increase the thickness of the plating applied by the barrel plating method.

  FIG. 6C is a diagram in which the distance of the end surface reaching portion 9A of the heat radiating member 9 of the resistor 1 shown in FIG. The heat radiating member 9E has the same effect as the heat radiating member 9D. Further, since the shape of the heat radiating member 9E is simpler than that of the heat radiating member 9D, there is an advantage that a pattern such as screen printing can be simplified and the screen printing accuracy can be increased.

  In FIG. 6D, the end side of the heat radiating member 9F from the end face reaching portion 9A to the end face non-reaching portion 9B of the heat radiating member 9F is an oblique line. By adopting this configuration, even if some peeling from the insulating substrate 2 occurs at the end face reaching portion 9A of the heat radiating member 9F, it becomes difficult to proceed. This is because as the peeling progresses, the fixing area between the heat dissipating member 9F and the insulating substrate 2 increases, and a larger force is required for the peeling force.

  In FIG. 6E, the end surface reaching portion 9A of the heat radiating member 9G extends to only one of the two opposing second end surfaces 2B. By adopting this configuration, it is possible to prevent the heat radiating member 9G from being separated from the insulating substrate 2 by secondary division as much as possible. Furthermore, by taking the other surface of the insulating substrate 2 larger than the heat radiating members 9C, 9D, and 9E by the heat radiating member 9G, a large heat radiating effect can be obtained.

  In FIG. 6F, an insulating substrate 2C having a hexagonal outer shape is used, a pair of back surface terminal electrodes 3D are formed in opposing edge regions of the insulating substrate 2C, and the heat dissipation member 9H is interposed between the back surface terminal electrodes 3D. The state in which is formed is shown. The heat dissipating member 9H has a simple shape that is easy to form (patterning) and has an outer shape that is almost rectangular. Even in such a simple shape, the end face reaching portion 9A and the end face non-reaching portion 9B can be formed by the hexagonal outer shape of the insulating substrate 2C. Here, it goes without saying that the outer shape of the insulating substrate 2C can be a regular hexagon. In addition to the right-angled rectangle such as a rectangle or a square, the shape in the plan view may be a hexagon as shown in FIG. 6F, a polygon such as a pentagon or an octagon, or the second end face 2B. It can be made into various shapes, such as the shape which swells in circular arc shape.

It is a figure which shows the resistor which concerns on embodiment of this invention, Comprising: (A) is a longitudinal cross-sectional view, (B) is a top view of the opposing surface (back surface) with a mounting circuit board. It is a longitudinal cross-sectional view which shows the state by which the resistor which concerns on embodiment of this invention was mounted in the mounting circuit board. It is a figure which shows order for the manufacturing process of the resistor which concerns on embodiment of this invention later on. It is a figure which shows the thickness of the metal film by the plating deposited on the surface of the resistor according to the embodiment of the present invention and the heat radiation member of the conventional resistor and the surface of the terminal electrode, (A) shows the thickness of the nickel plating layer In the figure, (B) shows the thickness of the tin plating layer. The result of the temperature impact test of the resistor according to the embodiment of the present invention, the conventional resistor, and the resistor without the heat radiating member (same as the resistor according to the embodiment of the present invention except for the heat radiating member) is shown. It is a figure and is a figure which shows resistance value change rate. It is a figure which shows the various modifications of the shape of the heat radiating member which concerns on embodiment of this invention. It is the longitudinal cross-sectional view of the conventional various resistors, and the top view of the opposing surface (back surface) with a mounting circuit board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resistor 2, 2C Insulation board | substrate 2A 1st end surface 2B 2nd end surface 3 Terminal electrode 3A Surface terminal electrode (a part of terminal electrode)
3B end face terminal electrode (part of terminal electrode)
3C, 3D Back terminal electrode (part of terminal electrode)
4 Resistor 5 First Glass Film 6 Second Glass Film 7 Nickel Plating Layer 8 Tin Plating Layer 9, 9C, 9D, 9E, 9F, 9G, 9H 2 End face reaching portion 9B End face non-reaching portion 10 Mounting circuit board 11 Solder 12 Large insulating substrate 13 Dividing groove 14 Trimming groove 15 Strip-like insulating substrate 16 Land

Claims (6)

A pair of terminal electrodes provided in an edge region of the insulating substrate and a resistive element disposed on one surface of the insulating substrate and having a resistor connected to both of the terminal electrodes, and the other surface of the insulating substrate In an electronic component having a heat radiating member for radiating heat of the resistance element, arranged so as not to contact the terminal electrode.
The heat dissipating member is a second end face different from the two first end faces of the insulating substrate facing the arrangement direction of the terminal electrodes, and is arranged to connect the two first end faces. An electronic component having a resistance element, comprising: an end surface reaching portion that is extended to two end surfaces; and an end surface non-reaching portion that is not stretched and is spaced apart from the second end surface.   The insulating substrate is a rectangular parallelepiped and has two opposing second end faces, and the heat radiating member has the end face reaching portion extended to both of the two second end faces. An electronic component having the resistance element according to claim 1.   The end surface side portion of the heat radiating member extending to the second end surface is provided with a distance between the first end surface reaching portion extended to the second end surface and the second end surface without extending. 3. The end face non-reaching part and the first end face reaching part extended to the second end face are arranged in this order along the second end face. Electronic component having a resistive element.   The heat dissipating member is a straight line in a direction along the second end surface, and has a line-symmetric shape with a straight line passing through a central region of the other surface of the insulating substrate as an axis of symmetry. An electronic component having the resistance element according to claim 1, 2 or 3.   One or a plurality of large insulating substrates having linear divisions that intersect the surface vertically and horizontally, each including at least a resistive element in each of the unit insulating substrates (hereinafter referred to as unit insulating substrates) surrounded by the linear division portions. A step of forming the circuit element and a conductive heat radiating member for radiating heat of the resistance element have a portion straddling the linear divided portion and a portion not straddling so as not to conduct with the resistance element. Forming the step, dividing the large insulating substrate into the individual unit insulating substrates along the linear dividing portion after both the steps, and then contacting the resistor elements to form terminals And a step of depositing a low melting point metal film on the surface of the terminal electrode and the surface of the heat dissipating member by barrel plating, and a method for producing an electronic component having a resistance element.   6. The manufacturing of an electronic component having a resistance element according to claim 5, wherein the thickness of the low melting point metal film deposited on the surface of the terminal electrode and the surface of the heat dissipation member is 3 μm or more and 12 μm or less. Law.

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