JP4769837B2 - Manufacturing method of semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor manufacturing technique, and more particularly to a technique effective when applied to a manufacturing method of a module product on which a chip component and a semiconductor chip are mounted.

  As an example of a module product (semiconductor device) on which a chip component of a surface mount type such as a chip capacitor or a chip resistor and a semiconductor chip for bare chip mounting are mounted, a so-called lithium battery monitoring module has been developed. The chip component and the semiconductor chip are mounted on the module substrate by solder connection, and both are covered and protected by an insulating high elastic resin.

  For example, Japanese Unexamined Patent Publication No. 2000-223623 (Patent Document 1) and Japanese Unexamined Patent Publication No. 11-238962 have a structure in which a chip component (surface-mounted component) and a semiconductor chip are mounted and both are covered with a resin. The gazette (patent document 2) has the description.

  First, JP 2000-223623 A discloses that the elastic modulus of the first resin covering the wire-bonded semiconductor chip and the wire is larger than the elastic modulus of the second resin covering the outside thereof. A technique for making the first resin harder than the second resin is described.

Japanese Patent Laid-Open No. 11-238962 discloses that a semiconductor element is solder-connected to a substrate via a solder bump and other surface-mounted components are also solder-connected to the substrate. A technique is described in which the mounted component is covered with a silicone gel.
JP 2000-223623 A JP-A-11-238962

  However, the present inventor has found the following problems regarding a semiconductor device having a structure in which the above-described chip component (surface mounted component) and a semiconductor chip are mounted and both are covered with a resin.

  That is, the semiconductor device (such as a module product) is soldered to a mounting board such as a printed wiring board by secondary mounting reflow, and at that time, the soldering component (surface mounting part) in the module is soldered again. Melting occurs, which causes problems such as short circuits.

  This phenomenon occurs when the solder remelts, and its melt expansion pressure causes the interface between the component and the resin (resin), or the interface between the resin and the module substrate to peel off, and the solder flows into the flash, where both ends of the surface mount component Are connected to each other to cause a short circuit.

  As a measure against the short circuit, the internal solder is not melted in the secondary mounting reflow, or the melt expansion pressure of the solder is eased even when the solder is melted, and the interface between the component and the resin or the resin and the module substrate. For example, a structure that does not cause peeling at the interface is considered.

  Therefore, as a countermeasure against the former, it is conceivable to use a high melting point solder for the internal solder. In this case, Sn-Pb solder is formed in advance on the terminal of the surface mount component, and furthermore, in a module in which wire bonding is performed. The terminal of the module board is gold-plated. Therefore, impurities such as Sn and gold are mixed with the internal solder, so that the melting point at the time of the secondary mounting reflow of the module drops even if high melting point solder is used. The internal solder melted, and as a result, it was found that the use of high melting point solder was not effective.

  On the other hand, as a countermeasure against the latter, it may be possible to relieve the melt expansion pressure of the melted internal solder using a gel-like resin having a low hardness (elastic modulus). The problem is that the mechanical strength is small.

  At that time, it is possible to protect the cover by covering it with a case or cap, but this is problematic in that it leads to an increase in cost.

  Further, it is conceivable to use a low melting point solder during the secondary mounting reflow of the module. However, since the low melting point solder has a short life, there is a problem that the reliability in the temperature cycle test is low.

  In addition, in the said Unexamined-Japanese-Patent No. 2000-223623 (patent document 1), there is no description about the technique which coat | covers the surface-mounted component (semiconductor chip) bonded by wire with resin with a low elastic modulus, and 2 of modules. There is no description of the short circuit due to the melt expansion pressure of the internal solder during the next mounting reflow as a problem.

  Moreover, although the said Unexamined-Japanese-Patent No. 11-238962 (patent document 2) describes the structure which covers the solder-connected semiconductor element and other surface mounting components with the gel-like resin with a low elastic modulus, There is no description of the specific allowable range of the elastic modulus of the gel-like resin, and there is no description of the short circuit due to the melt expansion pressure of the internal solder during the secondary mounting reflow of the module as a problem. Furthermore, a structure in which the outside of the gel-like resin is covered with a case is described, and using the case causes a problem of increasing costs.

  An object of the present invention is to provide a technique capable of preventing a short circuit due to remelting and flowing out of solder in a semiconductor device.

  Another object of the present invention is to provide a technique capable of reducing the cost.

  Furthermore, another object of the present invention is to provide a technique capable of making it possible to cope with Pb-free.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

  That is, the present invention is formed by a step of preparing a multi-piece substrate in which a plurality of device regions are partitioned by partition lines, a step of mounting a surface mount component on the device region by solder connection, and the solder connection. A plurality of solder connection portions of the device region and the surface-mounted components are collectively covered with an insulating elastic resin and resin-sealed to form a batch sealing portion on the multi-cavity substrate; Forming a cut portion on the surface of the batch sealing portion along a division line on the opposite side corresponding to the partition line of the multi-cavity substrate; and the multi-cavity substrate along the division line And a step of dividing the batch sealing portion into pieces by dividing the batch sealing portion with the cut portions.

  According to the present invention, when a semiconductor device is mounted by secondary mounting reflow, even if the internal solder connection portion is remelted, the pressure due to the melt expansion can be relieved by the elastic resin. It is possible to prevent the interface between the mounting component and the resin (resin) or the interface between the resin and the module substrate from peeling off.

  Thereby, it is possible to prevent the solder from flowing out to the interface, and it is possible to prevent occurrence of a short circuit between the terminals in the surface mount component.

  Further, the present invention is formed by a step of preparing a multi-piece substrate in which a plurality of device regions are partitioned by partition lines, a step of mounting a surface mount component on the device region by solder connection, and the solder connection. A plurality of solder connection portions of the device region and the surface-mounted components are collectively covered with an insulating elastic resin and resin-sealed to form a batch sealing portion on the multi-cavity substrate; A step of attaching a recognition mark to each surface of the device by a laser on the surface of the collective sealing portion, and dividing the multi-piece substrate along a division line on the opposite side corresponding to the partition line. And a process of performing.

  Further, the present invention is formed by a step of preparing a multi-piece substrate in which a plurality of device regions are partitioned by partition lines, a step of mounting a surface mount component on the device region by solder connection, and the solder connection. A plurality of solder connection portions of the device area and the surface mount component are printed using a squeegee so as to be covered with an insulating elastic resin at a time to form a batch sealing portion on the multi-chip substrate. And a step of dividing the multi-piece substrate along a division line on the opposite side corresponding to the partition line and dividing it into pieces.

  The present invention also provides a step of preparing a multi-piece substrate in which a plurality of rectangular device regions are partitioned by partition lines, and chip components and semiconductor chips, which are surface mounted components, are mounted on the device regions by solder connection. Forming a wire loop of a gold wire in a direction parallel to the longitudinal direction of the device region and wire bonding the surface electrode of the semiconductor chip and the substrate side terminal of the device region of the multi-chip substrate; and The solder connection portions of the plurality of device regions formed by the solder connection and the surface mount components are collectively covered with an insulating elastic resin and sealed with resin, and collectively sealed on the multi-chip substrate. Forming a multi-part substrate, and first dividing the multi-cavity substrate along a longitudinal line of the device region and on the opposite side of the dividing line corresponding to the partition line. After primary division, and a step of dicing by secondary divided along said parallel division line one row piece group formed in the width direction by the primary division.

  Of the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  (1). When the semiconductor device is mounted by secondary mounting reflow, the surface-mounted component to be solder-mounted and its solder connection portion are covered with a low-elasticity resin having an elastic modulus of 200 MPa or less at a temperature of 150 ° C. or higher. Even if the solder connection portion of the solder is remelted, the pressure due to the melt expansion can be relieved by the low elastic resin. As a result, it is possible to prevent the solder from flowing out to the interface between the surface mount component and the resin (resin), and to prevent the occurrence of a short circuit between the terminals of the surface mount component.

  (2). Since flow out to the solder interface can be prevented, it can be adapted to secondary mounting reflow, and when the low elastic resin has an elastic modulus of 1 MPa or more at a temperature of 25 ° C., A sufficient mechanical protection can be secured. Therefore, it is not necessary to cover with a case, a cap, etc., and cost reduction can be achieved.

  (3). By using a silicone resin as the low-elasticity resin, it is possible to perform resin printing application and mechanical division after printing in the state of a multi-piece substrate, so that sealing and singulation can be performed with an inexpensive method. Therefore, cost reduction can be achieved in the manufacture of the semiconductor device.

  (4). Since it is possible to prevent outflow to the interface due to remelting of the solder, it is not necessary to consider the melting point drop of the internal solder caused by the combination of the electrode specification of the surface mount component and the applicable solder, and the electrode specification of the surface mount component is solder plated. Or Sn plating, either of which can be adopted. As a result, it is possible to flexibly cope with the progress of the Pb-free process at the component manufacturer.

  In the following embodiments, the description of the same or similar parts will not be repeated in principle unless particularly necessary.

  Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), particularly when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and it may be more or less than the specific number.

  Further, in the following embodiments, the constituent elements (including element steps) are not necessarily essential unless explicitly stated or considered to be clearly essential in principle. Needless to say.

  Similarly, in the following embodiments, when referring to the shape, positional relationship, etc., of components, etc., the shape of the component is substantially the case unless specifically stated or otherwise considered in principle. And the like are included. The same applies to the numerical values and ranges.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof will be omitted.

(Embodiment)
1A and 1B are diagrams showing the structure of a Li-ion battery monitoring module as an example of a semiconductor device according to an embodiment of the present invention. FIG. 1A is a perspective view, FIG. 1B is a bottom view, and FIG. It is a figure which shows arrangement | positioning of each surface mounted component mounted in the module for Li ion battery monitoring shown, (a) is a plane arrangement | positioning figure, (b) is sectional drawing which shows the AA cross section of (a), FIG. FIG. 4 is a view showing an example of a solder connection structure of a chip capacitor in the surface-mounted component shown in FIG. 2, (a) is a cross-sectional view, (b) is an enlarged partial cross-sectional view showing a B portion of (a), and FIG. 1 is a circuit diagram showing an example of a circuit of a Li ion battery monitoring module shown in FIG. 1, and FIG. 5 is a characteristic diagram showing an example of a temperature characteristic of a low-elasticity resin used for a sealing portion of the Li ion battery monitoring module shown in FIG. FIG. 6 shows each table in the Li-ion battery monitoring module shown in FIG. FIG. 7 is a perspective view showing the structure of a multilayer ceramic substrate which is an example of a multi-chip substrate used for assembling the Li-ion battery monitoring module shown in FIG. 1, and FIG. FIG. 9 is a perspective view showing an example of a resin printing method in the assembly of the Li ion battery monitoring module shown in FIG. 1, and FIG. 9 is a diagram showing an example of a substrate dividing method in the assembly of the Li ion battery monitoring module shown in FIG. (A) is a plan view and a bottom view of the substrate before division, (b) is a plan view at the time of one-line division (primary division), (c) is a plan view at the time of secondary division (single division), FIG. 10 is a perspective view showing an example of a mounting state of the Li ion battery monitoring module shown in FIG. 1 on the mounting board, and FIG. 11 is a silicone tree when the board is divided in the assembly of the Li ion battery monitoring module shown in FIG. FIG. 12 is an enlarged partial cross-sectional view showing the remaining example, FIG. 12 is a view showing an example of the structure of the cut portion of the silicone resin in the assembly of the Li ion battery monitoring module shown in FIG. 1, and (a) is a substrate-resin perspective view. FIGS. 13A and 13B are perspective views of a cut portion, FIG. 13C is a perspective view of a groove portion by a laser, FIG. 13 is a perspective view showing an example of a marking method in assembling the Li ion battery monitoring module shown in FIG. It is a figure which shows an example of the board | substrate division | segmentation method in the assembly of the Li ion battery monitoring module shown in FIG. 1, (a) is a top view at the time of 1 row division (primary division), (b) is the part of (a) FIG. 15 is an enlarged plan view, (c) is a plan view at the time of secondary division, FIG. 15 is a process flow diagram showing an example of a method for assembling the Li ion battery monitoring module shown in FIG. (A) is an assembly flow diagram, (b) is a mounting flow diagram, FIG. 16 is a flow chart illustrating the principle of solder flow in a comparative module for the Li ion battery monitoring module shown in FIG. 1, and FIG. It is a perspective view which shows an example of the solder flow of the module of the comparative example shown in FIG.

  The semiconductor device of this embodiment shown in FIG. 1 is a module product called a Li (lithium) ion battery monitoring module 1. The surface mount component is solder-mounted on the module substrate 4, and the surface mount component is sealed. It has a structure covered with a stopping resin, and is mainly incorporated into a small portable electronic device such as a portable telephone.

  Note that the function of the Li-ion battery monitoring module 1 is to prevent an electrical injury in the battery cell by turning off the circuit immediately before an abnormality occurs due to, for example, a short circuit or excessive charging in a mobile phone. .

  As shown in FIG. 2, the configuration of the Li-ion battery monitoring module 1 includes a semiconductor chip 2 which is a surface-mounted component having a plurality of pads (surface electrodes) 2c formed on the main surface 2d, and connection terminals 3d at both ends. A chip component 3 that is a surface-mounted component on which the semiconductor chip 2 is formed, a module substrate 4 that is a wiring board on which the semiconductor chip 2 and the chip component 3 are mounted, and the substrate-side terminal 4a of the chip component 3 and the module substrate 4 , A solder wire 5 which is a bonding wire for connecting the pad 2c of the semiconductor chip 2 and the corresponding board side terminal 4a of the module substrate 4 corresponding to this, the semiconductor chip 2, the chip component 3, and the solder The figure formed of the low elastic resin (elastic resin) 6 shown in FIG. 8 such as an insulating silicone resin or a low elastic epoxy resin while covering the connecting portion 5 and the gold wire 8 Consisting sealing part 7 for indicating the.

  That is, by covering the chip component 3 soldered on the module substrate 4 with the low elastic resin 6, the solder remelting expansion pressure of the solder connection portion 5 generated at the time of secondary reflow (reflow to the mounting substrate at the shipping destination). 9 (refer to the comparative example in FIG. 16), the interface between the chip component 3 and the sealing portion 7 and the interface between the sealing portion 7 and the module substrate 4 are prevented from peeling off, and the solder flows out to the interface. 10 can be prevented.

  The low-elasticity resin 6 is a low-elasticity and insulating resin that has both a protective force (mechanical strength) that can protect internal components and a flexibility that can relieve the solder remelt expansion pressure 9 shown in FIG. Silicone resin (silicone rubber) A and low elastic epoxy resins B, C, and D having elastic modulus characteristics shown in FIG. 5 are preferable, and the conventional high elastic epoxy resin T is incompatible.

  Therefore, the allowable range of the elastic modulus of the low-elasticity resin 6 (resins A, B, C, and D shown in FIG. 5) of the present embodiment is a high temperature, that is, a secondary reflow temperature (generally about 230 ° C. ) And a temperature cycle test (for example, −40 to + 125 ° C.), the elastic modulus is preferably 200 MPa or lower at a temperature of 150 ° C. or higher in consideration of conditions at high temperature application.

  This is derived from FIG. 5 by an elastic modulus that can relieve the solder remelting expansion pressure 9 when the solder of the internal solder connection portion 5 is melted at a high temperature of 150 ° C. or higher. Resins A, B, C, and D are within the range, but resin T is incompatible outside the range.

  Furthermore, the low elastic resin 6 preferably has an elastic modulus of 1 MPa or higher at a temperature of 150 ° C. or higher, and the resins A, B, C, and D are within the range as shown in FIG.

  This is in consideration of the result that protection is possible as long as it has an elastic modulus of at least 1 MPa as a result of a test for protecting the surface-mounted components inside the sealing portion 7.

  Further, the temperature at the time of actual use (room temperature 25 ° C.) is also required to have an elastic modulus of at least 1 MPa as described above, and the resins A, B, C, and D are in the range as shown in FIG. Is within.

  Furthermore, it is more preferable to have an elastic modulus of 200 MPa or more in order to enhance the protective effect of the surface-mounted components at the temperature of actual use (normal temperature 25 ° C.). As shown in FIG. , D is within range, but resin A is out of range.

  However, since the resin A also has an elastic modulus of 1 MPa or more, there is no particular problem.

  In FIG. 5, the solder flow-out occurrence rate of each resin indicates the number of defects and the percentage thereof when the electrical short test of the chip component 3 is performed at 260 ° C. Yes, the denominator represents the number of tests, while the numerator represents the number of failures.

  According to this, the resin A, B, C, and D have a very low defect occurrence rate of 0 to 2%, whereas the non-conforming resin T has a very high defect occurrence rate of 70%.

  Moreover, in the reliability test by a temperature cycle, the resin A, B, C, D does not have a problem in particular.

  From the above, when, for example, a silicone resin (resin A) is used as the low-elasticity resin 6, considering the module reflow temperature margin and the mechanical strength (protective force) comprehensively, the elastic modulus is 2 to 2. 4 MPa is the best range.

  In other words, for example, when silicone resin (resin A) is adopted, the rubber hardness is in the range where the Shore hardness A70 to 80 is the best when considering the module reflow temperature margin and the mechanical strength (protective force) comprehensively. It is.

  In FIG. 5, a region P (shaded portion) indicates an optimum region in the splitting property of the low-elasticity resin 6 when the multi-layer ceramic substrate 11 that is the multi-piece substrate shown in FIG. 7 is divided into pieces. Further, the region Q (shaded portion) indicates a safe region of the low elastic resin 6 that is resistant to reflow.

  Further, in the low-elasticity epoxy resins B, C, and D shown in FIG. 5, the contents of, for example, silica contained in each are different, and the respective characteristics are slightly different.

  Here, as shown in FIG. 1A, the size of the Li-ion battery monitoring module 1 of the present embodiment is as follows: length (L) = 8 to 12 mm, width (M) = 3 to 5 mm, high It is a small size of about (N) = 1.6 mm (MAX). Further, as shown in FIG. 1B, seven external terminals 1a are provided on the rear surface.

  The pin functions of the seven external terminals 1a are, for example, terminal S is GND, terminal U is CP minus, terminal V is TM, terminal W is CP plus, terminal X is VCC, terminal Y is TES, and terminal Z is COM. .

  The module substrate 4 is a substrate formed of, for example, alumina ceramic.

  Next, main surface-mounted components mounted on the Li-ion battery monitoring module 1 of the present embodiment will be described with reference to FIG.

  As shown in FIG. 2A, two semiconductor chips 2 and six chip components 3 are mounted on the module substrate 4 of the Li ion battery monitoring module 1 as surface mount components.

  One of the two semiconductor chips 2 is a 2-channel transistor 2a, and the other is a controller 2b for a monitoring function for controlling the 2-channel transistor 2a.

  As shown in FIG. 2B, both are fixed to the board-side terminal 4a of the module board 4 by a solder connection portion 5 using solder. That is, the two semiconductor chips 2 are both solder-connected to the substrate-side terminal 4a using solder as a die bond material.

  Further, both chips are connected to the substrate side terminal 4a of the module substrate 4 by a gold wire 8, but for example, a gold wire 8 having a diameter of 50 μm is used for the 2-channel transistor 2a, while the controller 2b has For example, a gold wire 8 having a diameter of 27 μm is used.

  Of the six chip components 3, three are a chip resistor 3b, two are a ceramic chip capacitor 3a, and one is a chip thermistor 3c. Each has a connection terminal 3d at each end. The module-side board 4 is solder-connected to the board-side terminal 4 a by the solder connection portion 5.

  Since the semiconductor chip 2 is wire-bonded using the gold wires 8, a gold plating layer 4b is formed on the surface of each substrate-side terminal 4a as shown in FIGS. 3 (a) and 3 (b). Accordingly, each chip component 3 is also solder-connected to the board side terminal 4a having the gold plating layer 4b formed on the surface.

  As shown in FIG. 3B, the connection terminal 3d of the chip component 3 is composed of, for example, an Ag / Pd electrode 3e, a Ni base plating layer 3f, and a solder plating layer 3g in order from the lower layer. The terminal 4a is composed of a Cu copper body 4c, a Ni base plating layer 4d, and a gold plating layer 4b in order from the lower layer, and an area other than the location where the solder connection portion 5 is formed on the substrate side terminal 4a is an insulating film (solder). It is covered and insulated by an overcoat glass 4e which is a resist film.

  Therefore, in the module substrate 4, the gold plating layer 4 b is formed on the surface of all the board-side terminals 4 a, and the chip component 3 is solder-connected to the gold plating layer 4 b at the connection terminal 3 d and the semiconductor chip 2. The pad 2c is connected to the gold wire 8, and the gold wire 8 is further connected to the gold plating layer 4b on the surface of the substrate side terminal 4a.

  At that time, the wire loop 8a of the gold wire 8 shown in FIG. 2 (b) is bonded so as to be formed in a direction substantially parallel to the longitudinal direction of the rectangular module substrate 4 as shown in FIG. 2 (a). ing.

  That is, in the module substrate 4, the substrate-side terminals 4 a are arranged such that the gold wires 8 are wired in a direction substantially parallel to the longitudinal direction of the rectangular module substrate 4.

  FIG. 6 shows the melting points of the solder of each solder connection portion 5 and the single solder in the eight surface-mounted components mounted on the module substrate 4, and according to this, the chip component 3 (ceramic chip capacitor) is shown. It can be seen that the melting points of 3a, chip resistor 3b, and chip thermistor 3c) are low.

  Next, the operation of the circuit of the Li-ion battery monitoring module 1 shown in FIG. 4 will be described.

  In the Li-ion battery monitoring module 1 shown in FIG. 1, the GND terminal is connected to the negative terminal of the battery cell, and the VP-terminal connected to the negative terminal of the mobile phone is connected to the same wiring via the two-channel transistor 2a. It has become.

  Therefore, this wiring is a cathode wiring that connects the battery cell and the portable telephone.

  The 2-channel transistor 2a is an element that turns off the circuit when an abnormality occurs, and the controller 2b is an element that monitors the potential of each wiring in order to control the 2-channel transistor 2a.

  Hereinafter, the specific operation of the circuit shown in FIG. 4 will be described. Normally, when a portable telephone is used, the CHG terminal and DCH terminal of the controller 2b (monitoring function IC) are at a potential for turning on the two-channel transistor 2a. Thus, a current is supplied from the battery cell to the mobile phone (current flows from VP− to the GND side).

  When an abnormality such as a short circuit or a large current flows in the portable telephone, a slight potential difference occurs between the IDT terminal and the GND terminal of the controller 2b due to a voltage drop corresponding to the minute resistance of the 2-channel transistor 2a. Detecting this, the potential of the DCH terminal becomes a potential for turning off one channel of the two-channel transistor 2a.

  Thereby, the electric current supply from a battery cell stops and an accident can be prevented beforehand.

  In addition, both the two-channel transistors 2a are in an on state during charging, and current is supplied from the portable telephone side to the battery cell (current flows from GND to VP−).

  Note that if the battery is overcharged, such as when the charging time is exceeded, the VCC terminal of the controller 2b is connected to the positive terminal of the battery cell, so if the potential difference from GND exceeds a certain level, this is detected. Thus, the potential of the CHG terminal is a potential for turning off one channel of the two-channel transistor 2a.

  As a result, the current supply from the charger to the battery cell via the portable telephone is stopped, and an accident can be prevented.

  Next, a manufacturing method of the semiconductor device (Li ion battery monitoring module 1) of the present embodiment will be described along the module assembly procedure shown in FIG.

  First, as shown in step S1, a multilayer ceramic substrate 11 is prepared which is a multi-piece substrate in which a plurality of module regions 11a (for example, about 120 devices) are partitioned by partition lines 11b.

  As shown in FIG. 7, when the multilayer ceramic substrate 11 includes 120 module regions 11 a, the size is, for example, about (P) 80 mm × (Q) 80 mm, and the thickness is About 0.5 mm. However, a glass epoxy substrate other than the multilayer ceramic substrate 11 may be used as the multi-cavity substrate.

Further, the circuit shown in FIG. 4 is patterned in each module region 11a, and the gold plating layer 4b shown in FIG. 3B is formed on the surface of each substrate side terminal 4a.

  Subsequently, solder paste printing shown in step S2 is performed, and then a plurality of surface-mounted components are mounted on each module region 11a by solder connection (step S3).

  That is, after printing a solder paste on each substrate side terminal 4a, surface mount components such as a ceramic chip capacitor 3a, a chip thermistor 3c, a chip resistor 3b and a semiconductor chip 2 are arranged on a predetermined substrate side terminal 4a, and then As shown in step S4, reflow is performed, whereby each surface mount component is soldered.

  The solder of the solder connection portion 5 has a fillet shape as shown in FIG.

  Thereafter, cleaning shown in step S5 is performed, and then wire bonding shown in step S6 is performed.

  Here, the pads 2 c of the semiconductor chip 2 and the substrate-side terminals 4 a having the gold plating layer 4 b formed on the surface of the module substrate 4 are wire-bonded using the gold wires 8.

  At this time, as shown in FIG. 2A, a wire loop 8a of the gold wire 8 (see FIG. 2B) is formed in a direction substantially parallel to the longitudinal direction of the rectangular module substrate 4.

  Then, resin (resin) printing application shown in Step S7 is performed.

  Here, the solder connection portions 5 of the plurality of module substrates 4 formed by solder connection, two semiconductor chips 2 (two-channel transistors 2a and controller 2b), and six chip components 3 (ceramic chip capacitor 3a and chip resistor 3b). And the chip thermistor 3c) are printed using a squeegee 12 as shown in FIG. 8 so as to be covered with the insulating low elasticity resin 6 such as silicone resin or low elasticity epoxy resin shown in FIG. Then, the batch sealing portion 13 is formed on the multilayer ceramic substrate 11.

  That is, as shown in FIG. 8, a low-elasticity resin 6 such as a silicone resin or a low-elasticity epoxy resin is applied to a multilayer ceramic substrate 11 after component mounting and wire bonding using a metal mask 14 and a squeegee 12. The batch sealing portion 13 is formed by applying the low-elasticity resin 6 by a printing method so as to collectively cover the plurality of module regions 11a.

  Further, baking / resin curing shown in step S8 is performed to form the resin-coated substrate 15.

  That is, the batch sealing portion 13 formed by the printing method is baked and cured to form the resin-coated substrate 15.

  Thereafter, the division shown in step S9 is performed to separate the multilayer ceramic substrate 11 into pieces.

  In addition, in the manufacturing method of the Li ion battery monitoring module 1 of the present embodiment, the multilayer ceramic substrate 11 has its partition line 11b shown in FIG. 7 formed on its surface side (component mounting side). As shown in FIG. 9A and FIG. 11, a snap line (split line) 11c, which is a small groove for splitting, is formed on the opposite side (back side), and a multilayer ceramic is formed along the snap line 11c. The substrate 11 is divided (divided into individual pieces).

  Thereby, the multilayer ceramic substrate 11 can be easily divided by a mechanical force.

  When dividing, first, a multilayer ceramic substrate 11 on which the collective sealing portion 13 shown in FIG. 9A is formed is prepared, followed by one-line division (primary division) shown in FIG. 9B. ) To form a single-row piece group 11d, and then divide into pieces (secondary division) as shown in FIG. 9C to divide into individual modules.

  After the division, the electrical characteristic test shown in step S10 is performed, and the module shown in step S11 is completed.

  As a result, the Li-ion battery monitoring module 1 shown in FIG. 1 can be assembled.

  Next, the module secondary mounting process shown in FIG.

  As shown in FIG. 1B, solder is mounted on the back surface of the module substrate 4 of the Li-ion battery monitoring module 1 so that it can be mounted on the printed wiring board 16 that is the mounting substrate at the shipping destination shown in FIG. An external terminal 1a for connection is formed.

  Therefore, the shipping destination of the Li-ion battery monitoring module 1 first prepares a printed wiring board 16 for mounting, which is a PCB board, as shown in step S21, and then prints the printed wiring board 16 as shown in step S22. Print the solder paste on.

  Further, after placing the Li ion battery monitoring module 1 on the printed wiring board 16 as shown in step S23 (module mounting shown in step S23), reflow is performed as shown in step S24.

  That is, as shown in FIG. 10, the solder connection portion 5 is formed by solder reflow, and the Li ion battery monitoring module 1 is reflow mounted on the printed wiring board 16.

  Thereafter, as shown in step S25, an electrical characteristic test is performed to complete the mounting shown in step S26.

  Next, the characteristic part which produces an effect further in manufacture of the module 1 for Li ion battery monitoring of this Embodiment is demonstrated.

  First, when a low-elasticity epoxy resin having a relatively high hardness is employed as the low-elasticity resin 6, for example, the low-elasticity epoxy resin is mechanically easy in the dividing step shown in step S9 in FIG. Can be divided. When a silicone resin is used as the low-elasticity resin 6, as shown in FIG. 11, in the silicone resin, a silicone resin residue 13b that is a part that cannot be divided remains.

  This is a phenomenon due to the soft characteristics of the silicone resin.

  Therefore, as a countermeasure against the remaining silicone resin 13b, the snap line 11c shown in FIG. 9A and FIG. 11 corresponding to the partition line 11b shown in FIG. 7 formed on the surface side (component mounting side) of the multilayer ceramic substrate 11 is used. Accordingly, by forming the cut portion 13a on the surface of the collective sealing portion 13 as shown in FIG. 12A, it is possible to improve the generation of burrs at the time of division and the dimensional accuracy.

  The cut portion 13a is like a V-groove shown in FIG. 12B, and is cut by a cutting device having a sharp blade to form the cut portion 13a.

  As a result, when the multilayer ceramic substrate 11 is divided, the multilayer ceramic substrate 11 is divided along the snap lines 11c, and the collective sealing portion 13 is divided into individual pieces by the cut portions 13a.

  Therefore, by forming the cut portion 13a on the surface of the collective sealing portion 13, it is possible to improve the division workability in the case of a soft resin such as a silicone resin.

  Further, instead of the notch 13a shown in FIG. 12B, for example, a laser such as a YAG laser or a carbon dioxide laser is used to form a groove 13c on the surface of the collective sealing portion 13 as shown in FIG. It may be formed, and the division workability can be improved as described above.

  In this case, by adjusting the intensity of the laser beam, the depth of the groove 13c can be adjusted, and the division workability can be further improved.

  Further, when the groove 13c is formed by a laser, a device having a mechanism capable of accurately measuring the position of the snap line 11c in the multilayer ceramic substrate 11 by an optical method is used, so that the snap line 11c is formed on the line to be divided. It is possible to accurately form the groove 13c on a line corresponding to the above, and to improve the division workability.

  In addition, by forming the notch part 13a shown in FIG. 12B or the groove part 13c by the laser shown in FIG. 12C, the direction in which the back surface side of the multilayer ceramic substrate 11 is necessarily opened as shown in FIG. There is no need to mechanically divide into two, and it is also possible to divide mechanically in the direction of opening the surface side of the collective sealing portion 13 on the opposite side for convenience of a dividing device or the like.

  However, in that case, the snap line 11c shown in FIG. 11 needs to be provided not on the back surface side of the multilayer ceramic substrate 11 but on the front surface side (component mounting surface side).

  Further, the division of the multilayer ceramic substrate 11 is not mechanical division as shown in FIG. 9, but dicing cutting may be performed with a blade rotating at high speed (a cutting blade of a grindstone).

  In this case, the cut surface can be cut with high dimensional accuracy.

  Thereby, the clearance of the distance from a cutting | disconnection edge part to a wiring pattern can be reduced in design, and it can be effective for the miniaturization design of the module 1 for Li ion battery monitoring.

  Further, when the groove 13c is formed using a laser, the recognition mark 17 such as the product number shown in FIG. 13 to be provided on the product (Li-ion battery monitoring module 1) is provided with the same laser together with the formation of the groove 13c. Thus, each module area 11a (see FIG. 7) can be drawn.

  That is, the formation of the groove 13c and the formation of the recognition mark 17 can be performed together, and the work efficiency can be improved.

When the low-elasticity resin 6 is a silicone resin, the recognition mark 17 attached by the laser can be clearly formed, and the recognition mark 17 with good readability can be attached.

  This is because the surface of the silicone resin is a glossy surface, whereas the recognition mark 17 formed by the laser is burned and carved to become blackish, and therefore the recognition mark 17 becomes clear due to light and dark. It is.

  Further, when the multilayer ceramic substrate 11 is mechanically divided, first, as shown in FIG. 14A, the resin-coated substrate 15 is attached to the snap line 11c along the longitudinal direction of the module region 11a (see FIG. 7). After the primary division, the one-row piece group 11d shown in FIG. 14B formed by the primary division is secondarily divided along the snap line 11c parallel to the width direction. Then, as shown in FIG.

  In wire bonding, as shown in FIG. 14B, the electrode arrangement of the module region 11a shown in FIG. 7 is performed so that the gold wire 8 is wire-bonded in a direction substantially parallel to the longitudinal direction of the rectangular module region 11a. Form it.

  Accordingly, during the primary division (one-line division) shown in FIG. 14A, the division along the width direction with respect to the longitudinal direction of the rectangular multilayer ceramic substrate 11 has a strong force on the individual module regions 11a. It is also possible that the substrate itself is distorted as a result of this, but the direction of the wire loop 8a of the gold wire 8, that is, the wire bonding of the gold wire 8 is performed in a direction substantially parallel to the longitudinal direction of the module region 11a. Even if the substrate itself is distorted during the next division, the influence on the gold wire 8 can be eliminated.

  As a result, a good Li-ion battery monitoring module 1 can be assembled.

  According to the semiconductor device (Li ion battery monitoring module 1) and the manufacturing method thereof in the present embodiment, the semiconductor chip 2 and the chip component 3 that are surface mount components and the respective solder connection portions 5 are 150 ° C. or higher. Even when the internal solder connection part 5 is remelted when the Li-ion battery monitoring module 1 is mounted by secondary mounting reflow by being covered with the low elastic resin 6 having an elastic modulus of 200 MPa or less at the temperature, The pressure due to the melt expansion (solder remelt expansion pressure 9 shown in FIG. 16) can be relaxed by the low elastic resin 6.

  As a result, it is possible to prevent the interface between the surface mount component and the resin (low elastic resin 6) or the interface between the resin and the module substrate 4 from peeling off.

  Thereby, it is possible to prevent the solder 10 from flowing out to the interface (see FIG. 16), thereby preventing the occurrence of a short circuit between the connection terminals 3d in the surface mount component.

  Here, as shown in the comparative example of FIG. 16 and FIG. 17, in the conventional solder mounting of the chip component 18, the connection terminals 18a shown in FIG. 17 are plated with 90% Sn / 10% Pb solder. Good wettability.

  The solder connection portion 18b uses Pb-based high-temperature solder having a melting point (solid phase line) of 245 ° C., and is a material selection that is difficult to be remelted in the secondary mounting reflow.

  However, in the module assembly reflow, the Sn of the plating of the connection terminal 18a is melted into the solder connection portion 18b to form a Pb-Sn eutectic phase, and the melting point of the Pb-based high-temperature solder is lowered.

  As a result, at the time of secondary mounting reflow, as shown in FIG. 16, the solder connection portion 18b is in a remelted state, and since the high-hardness resin 20 is used, the solder remelting expansion pressure 9 of the solder connection portion 18b. Becomes higher than the resin pressure 19, and the interface between the high-hardness resin 20 and the chip component 18 is in a peeled state, and a solder flow 10 is generated in the gap in the gap, resulting in a short circuit failure.

  On the other hand, in the Li-ion battery monitoring module 1 of the present embodiment, since the outflow 10 to the solder interface can be prevented, it is possible to cope with the secondary mounting reflow.

  Furthermore, when the low elastic resin 6 has an elastic modulus of 1 MPa or more at a temperature of 25 ° C., a sufficient mechanical protection force (mechanical strength) can be ensured.

  Therefore, it is possible to sufficiently protect the inside of the sealing portion 7 while preventing the outflow 10 to the interface due to remelting of the solder.

  As a result, it is not necessary to cover the case with a case or a cap, so that the cost can be reduced.

  By using a silicone resin as the low-elasticity resin 6, it is possible to perform resin printing application and mechanical division after printing in the state of the multilayer ceramic substrate 11, so that sealing or singulation is performed by an inexpensive method. be able to.

  Therefore, cost reduction can be achieved in the production of the Li-ion battery monitoring module 1.

  Further, since it is possible to prevent the outflow 10 from flowing out to the interface due to the remelting of the solder, the electrode specifications of the surface mount component such as the semiconductor chip 2 and the chip component 3 to be solder mounted on the Li ion battery monitoring module 1 and the applicable solder There is no need to consider the melting point drop of the internal solder caused by the combination, and the electrode specifications of the surface mount component may be solder plating or Sn plating, either of which can be adopted.

  Thereby, regarding Pb-free, it becomes possible to respond flexibly in accordance with the progress of Pb-free at the part maker, and therefore, the range of market needs can be greatly expanded.

  Note that the solder used for assembling the Li-ion battery monitoring module 1 does not necessarily need to be a high-temperature solder, and there is no problem in using 60% Sn / 40% Pb (eutectic solder). Even when a high temperature cannot be applied to the substrate, it can be handled without losing the characteristics of the Li-ion battery monitoring module 1.

  Moreover, when adopting a silicone resin as the low-elasticity resin 6, the thermal conductivity of the sealing portion 7 can be improved by adjusting the filler content of the silicone resin. As the Li-ion battery monitoring module 1, The thermal resistance, which is one of the important characteristics, can be reduced.

  In addition, the internal solder of the Li-ion battery monitoring module 1 may be a solder with a low melting point, for example, a Pb-free solder such as bismuth-containing solder, instead of a melting point drop due to melting of the component terminal plating into the solder. A module having a melting point lower than the temperature at which the Li-ion battery monitoring module 1 is reflow-mounted at the shipping destination can be applied without any problem.

  Further, by adopting a silicone resin as the low-elasticity resin 6, since the silicone resin (silicone rubber) is soft, even if the module substrate 4 is a ceramic substrate or a glass-filled epoxy substrate, its warpage is reduced. Therefore, the potential for trouble in the manufacturing apparatus due to the substrate warpage in the module assembly process can be reduced.

  Furthermore, by adopting a silicone resin as the low-elasticity resin 6, even if the module substrate 4 is a ceramic substrate or a glass-containing epoxy substrate, the warpage can be reduced. Can be improved.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments of the invention. However, the present invention is not limited to the embodiments of the invention, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

  For example, in the above embodiment, the case where the low elastic resin 6 is a silicone resin or a low elastic epoxy resin has been described as an example. However, the low elastic resin 6 has an allowable elastic modulus range described in the above embodiment. If it is a thing, a gel-like thing etc. may be sufficient.

  In the above embodiment, the case where the semiconductor device is the Li-ion battery monitoring module 1 has been described. However, the semiconductor device includes a surface-mounted component that is solder-mounted, and the surface-mounted component is a low-elasticity resin. Other semiconductor devices such as a high-frequency module (high-frequency power amplifying device) may be used as long as the structure is sealed by 6.

  Further, the surface mounting component is not limited to a chip component or a semiconductor chip, but may be other electronic components as long as it is a surface mounting component to be solder mounted.

  In the semiconductor device, a semiconductor chip and a wiring board are arranged to face each other, and a surface electrode of the semiconductor chip and a substrate on which a gold plating layer, a Sn plating layer, or a Pb-Sn solder plating layer is formed. The side terminals may be bump-connected via gold bumps or solder bumps.

  The present invention is suitable for a technique for manufacturing a module product having a chip component and a semiconductor chip.

(A), (b) is a figure which shows the structure of the module for Li ion battery monitoring which is an example of the semiconductor device of embodiment of this invention, (a) is a perspective view, (b) is a bottom view. . (A), (b) is a figure which shows arrangement | positioning of each surface mounting component mounted in the module for Li ion battery monitoring shown in FIG. 1, (a) is a plane arrangement | positioning figure, (b) is a figure of (a). It is sectional drawing which shows an AA cross section. (A), (b) is a figure which shows an example of the solder connection structure of the chip capacitor in the surface mount component shown in FIG. 2, (a) is sectional drawing, (b) is an enlarged part which shows the B section of (a) It is sectional drawing. It is a circuit diagram which shows an example of the circuit of the module for Li ion battery monitoring shown in FIG. It is a characteristic view which shows an example of the temperature characteristic of the low elasticity resin used for the sealing part of the module for Li ion battery monitoring shown in FIG. FIG. 2 is a melting point data diagram showing an example of a melting point of each surface mount component in the Li ion battery monitoring module shown in FIG. 1. It is a perspective view which shows the structure of the multilayer ceramic substrate which is an example of the multi-cavity board | substrate used for the assembly of the Li ion battery monitoring module shown in FIG. It is a perspective view which shows an example of the resin printing method in the assembly of the module for Li ion battery monitoring shown in FIG. (A), (b), (c) is a figure which shows an example of the board | substrate division | segmentation method in the assembly of the module for Li ion battery monitoring shown in FIG. 1, (a) is the top view and bottom view of the board | substrate before division | segmentation (B) is a top view at the time of 1 row | line | column division | segmentation (primary division | segmentation), (c) is a top view at the time of secondary division | segmentation (separation). It is a perspective view which shows an example of the mounting state to the mounting board | substrate of the Li ion battery monitoring module shown in FIG. It is an expanded partial sectional view which shows an example of the silicone resin remaining at the time of the board | substrate division | segmentation in the assembly of the Li ion battery monitoring module shown in FIG. (A), (b), (c) is a figure which shows an example of the structure of the cut | notch part of the silicone resin in the assembly of the module for Li ion battery monitoring shown in FIG. 1, (a) is a board | substrate-resin perspective view, (B) is a perspective view of a notch part, (c) is a perspective view of the groove part by a laser. It is a perspective view which shows an example of the marking method in the assembly of the module for Li ion battery monitoring shown in FIG. (A), (b), (c) is a figure which shows an example of the board | substrate division | segmentation method in the assembly of the module for Li ion battery monitoring shown in FIG. 1, (a) is at the time of 1 row division (primary division) (B) is a partially enlarged plan view of (a), and (c) is a plan view at the time of secondary division. (A), (b) is a process flow figure which shows an example of the assembly method of the module for Li ion battery monitoring shown in FIG. 1, and the mounting procedure of a secondary mounting process, (a) is an assembly flow figure, (b) Is a mounting flow diagram. It is a flow-out explanatory drawing which shows the principle of the solder flow in the module of the comparative example with respect to the module for Li ion battery monitoring shown in FIG. It is a perspective view which shows an example of the solder flow of the module of the comparative example shown in FIG.

Explanation of symbols

1 Li-ion battery monitoring module (semiconductor device)
1a External terminal 2 Semiconductor chip (surface mount component)
2a 2 channel transistor 2b controller 2c pad (surface electrode)
2d Main surface 3 Chip parts (surface mount parts)
3a Ceramic chip capacitor 3b Chip resistor 3c Chip thermistor 3d Connection terminal 3e Ag / Pd electrode 3f Ni base plating layer 3g Solder plating layer 4 Module substrate (wiring substrate)
4a Substrate side terminal 4b Gold plating layer 4c Cu copper body 4d Ni base plating layer 4e Overcoat glass 5 Solder connection part 6 Low elastic resin (elastic resin)
7 Sealing part 8 Gold wire 8a Wire loop 9 Solder remelting expansion pressure 10 Flowing out 11 Multilayer ceramic substrate (multiple substrate)
11a Module area (equipment area)
11b Partition line 11c Snap line (split line)
11d 1 row single piece group 12 squeegee 13 collective sealing part 13a notch part 13b remaining silicone resin 13c groove part 14 metal mask 15 resin coated substrate 16 printed wiring board 17 recognition mark 18 chip component 18a connection terminal 18b solder connection part 19 resin pressure 20 High hardness resin

Claims (4)

Preparing a multi-piece substrate in which a plurality of device areas are partitioned by a partition line;
Mounting a surface mount component by solder connection in the device area;
A plurality of solder connection portions of the device region formed by the solder connection and the surface mount components are collectively covered with an insulating elastic resin and resin-sealed so as to be collectively sealed on the multi-chip substrate. Forming a step;
Forming a cut portion on the surface of the batch sealing portion along a division line on the opposite side corresponding to the partition line of the multi-cavity substrate;
Wherein with the multi-chip substrate is divided along the dividing line, possess a step of individual pieces by dividing the collective sealing portion at the cut portion,
When using a silicone resin as the elastic resin,
A step of forming a groove corresponding to the dividing line of the multi-cavity substrate on the surface of the collective sealing portion by a laser, and a recognition mark for each device region on the surface of the collective sealing portion using the same laser the method of manufacturing a semiconductor device, characterized by chromatic and a step of subjecting the. Preparing a multi-piece substrate in which a plurality of device areas are partitioned by a partition line;
Mounting a surface mount component by solder connection in the device area;
A plurality of solder connection portions of the device region formed by the solder connection and the surface mount components are collectively covered with an insulating elastic resin and resin-sealed so as to be collectively sealed on the multi-chip substrate. Forming a step;
Attaching a recognition mark to each surface of the device by a laser on the surface of the batch sealing portion;
Possess a step of singulated divided along the dividing line on the opposite side of the matrix substrate corresponding to the partition line,
When using a silicone resin as the elastic resin,
A step of forming a groove corresponding to the dividing line of the multi-cavity substrate on the surface of the collective sealing portion by a laser, and a recognition mark for each device region on the surface of the collective sealing portion using the same laser the method of manufacturing a semiconductor device, characterized by chromatic and a step of subjecting the. Preparing a multi-piece substrate in which a plurality of rectangular device regions are partitioned by a partition line;
Mounting a chip component and a semiconductor chip that are surface-mounted components by solder connection in the device region;
Forming a wire loop of a gold wire in a direction parallel to the longitudinal direction of the device region and wire bonding the surface electrode of the semiconductor chip and the substrate side terminal of the device region of the multi-cavity substrate;
A plurality of solder connection portions of the device region formed by the solder connection and the surface mount components are collectively covered with an insulating elastic resin and resin-sealed so as to be collectively sealed on the multi-chip substrate. Forming a step;
The multi-chip substrate is primarily divided along the longitudinal direction of the device area and on the opposite division line corresponding to the partition line, and after the primary division, one row formed by the primary division. And a step of dividing the group of individual pieces along the dividing line parallel to the width direction into individual pieces. 4. The method of manufacturing a semiconductor device according to claim 3, wherein when a silicone resin is used as the elastic resin, a groove corresponding to the dividing line of the multi-cavity substrate is formed on the surface of the collective sealing portion by a laser. And a step of attaching a recognition mark for each device region to the surface of the collective sealing portion using the same laser.

Images