JP2007134848A - Surface mounting quartz resonator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface mounting resonator of H cross-section structure having an inspection electrode of a quartz vibrator on the side face in which hermetic seal is ensured. <P>SOLUTION: The surface mounting quartz resonator comprises a container body composed of laminate ceramic including a central layer consisting of at least first and second planar layers, and upper and lower frame layers having an opening and provided with recesses in both major surfaces, wherein the outer circumferential part of a crystal piece having an extended lead-out electrode is bonded to a first crystal terminal provided on the bottom face of one recess and sealed hermetically, and the IC terminal of an IC chip is bonded to a circuit terminal including a second crystal terminal provided on the bottom face of the other recess. The first crystal terminal is connected electrically with the second crystal terminal through first and second via holes provided in the first and second layers of the central layer, and connected electrically with the inspection electrode of a quartz vibrator provided on the outer side face of the container body through the first via hole and the lamination surface of the first and second layers. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention has a technical field of a crystal oscillator for surface mounting (hereinafter, referred to as a surface mount oscillator) using a container body 1 having an H-shaped cross section having recesses on both main surfaces, and in particular, examines vibration characteristics of a crystal resonator. The present invention relates to a surface mount oscillator having a crystal inspection terminal.

  A surface-mounted oscillator is small and light, and for example, a temperature-compensated type has high frequency stability. Therefore, the surface-mounted oscillator is applied to a portable electronic device including a mobile phone or the like as a frequency or time reference source. In recent years, further miniaturization has progressed, and further miniaturization is demanded for surface mount oscillators.

(Example of conventional technology)
FIG. 3 is a diagram of a surface-mount oscillator for explaining a conventional example, in which FIG. 3 (a) is a sectional view and FIG. 3 (b) is a bottom view.

  The surface mount oscillator includes a container body 1, a crystal piece 2, and an IC chip 3. The container body 1 is made of a laminated ceramic having a cross-section H structure having recesses on both main surfaces. For example, if the first layer A and the second layer B are used, a flat central layer 1a and an upper and lower frame layer 1 (bc) having openings. ). The shield electrode layer 4 is provided between the first layer A and the second layer B of the central layer 1a, and the mounting electrodes 5 are provided at the four corners of the lower frame layer serving as the other recess.

  The crystal piece 2 has excitation electrodes (not shown) on both main surfaces, and the extraction electrodes extend to the outer peripheral portions on both sides of one end. Then, both ends of the extended end portion of the extraction electrode are fixed to the pair of first crystal terminals 6 provided on the bottom surface of one of the recesses of the container body 1 by the conductive adhesive 7. The metal cover 11 is bonded to a metal ring (not shown) provided on the upper surface of the upper frame layer 1b, and the crystal piece 2 is hermetically sealed.

  The IC chip 3 has a plurality of IC terminals (not shown) on the circuit function surface. The IC terminal includes a pair of crystal terminals and a power source, an output, a ground, and an automatic frequency control (AFC) terminal that are electrically connected to the mounting electrode 5. However, the temperature compensation type has a temperature compensation data write terminal 10 (ab). And it adheres to each circuit terminal 8 including the 2nd crystal terminal 8a provided in the other recessed part bottom face of the container main body 1 by ultrasonic thermocompression using a bump (so-called flip chip bonding).

  The pair of first crystal terminals 6 and the second crystal terminals 8a are connected by a pair of crank-shaped first and second via holes 9 (ab) provided in the central layer 1a of the container body 1. Usually, the bottom surface of the other concave portion is connected to the first and second crystal terminals 8a, and the crystal inspection terminals X (1, 2) having a larger shape are connected to the first and second crystal terminals 8a. A write terminal 10 (ab) that is electrically connected to the write IC terminal of the IC chip 3 is formed on the side surface of the container body 1. The IC chip 3 and the crystal piece 2 (excitation electrode) are electrically cut off by the shield electrode layer 4.

  In such a case, after a metal cover 11 is joined to one concave portion of the container body 1 to form a crystal resonator, a probe from a measuring instrument (not shown) is brought into contact with the crystal inspection terminal X (1, 2). Measure the vibration characteristics of the crystal unit. If there is an abnormality in, for example, the crystal impedance of the crystal unit alone, it is discarded. Then, the IC chip 3 is mounted only on the non-defective product and, for example, a protective resin (not shown) is applied (underfill).

(Problems of conventional technology)
However, in the surface mount oscillator having the above-described configuration, the crystal inspection terminal X (1, 2) provided on the bottom surface of one of the recesses is covered with the IC chip 3, and in particular after commercialization with an underfill, the crystal resonator alone There was a problem that the vibration characteristics of the can not be measured. In this case, for example, if there is an accident that causes an oscillation failure after product shipment, the crystal resonator cannot be analyzed, making it difficult to determine the true cause of the oscillation failure.

  In addition, the smaller the surface-mounted oscillator, for example, the smaller the planar outer shape is 3.2 × 2.5 mm, the smaller the bottom surface of the concave portion of the container body 1 and the sufficiently large crystal inspection terminals X (1, 2) X1, X2 are formed. Becomes difficult. The crystal inspection terminal X (1, 2) requires, for example, 0.6 × 0.6 mm or more because of the relationship with the probe from the measuring instrument, etc., but in this case, it becomes less than this, making reliable measurement difficult.

  For this reason, for example, a crystal inspection terminal X (1 on the outer surface of the container body 1 is well known as a one-chamber surface mount oscillator in which the IC chip 3 is fixed to the bottom of the recess and the crystal piece 2 is fixed to the inner wall step. , 2) was considered to place. That is, the first crystal terminal 6 to which the crystal piece 2 is fixed is connected to the crystal inspection terminal X (1, 2) provided on the outer surface through the conductive path 12 on the laminated surface. In this case, the second crystal terminal 8a on the inner bottom surface is electrically connected through the first via hole 9a on the inner wall step. The thickness of the conductive path 12 is smaller than the thickness of the first crystal terminal 6.

  When this is applied to the H-structure container body 1 as it is, as shown in the figure, the crystal inspection terminal X (1, 2) on the outer surface passes through the conductive path 12 on the laminated surface of the upper frame layer and the central layer 1a. Connect to. However, as the size is reduced, the width of the upper frame layer of the container body 1 (H structure) is also reduced, so that the through path of the conductive path 12 on the laminated surface is shortened. For this reason, there is a possibility that an airtight leak which becomes a fatal defect for the crystal unit due to an impact or the like occurs. It should be noted that the bonding strength is higher when there is no conductive path (electrode film) on the laminated surface of the laminated ceramic.

(Object of invention)
It is an object of the present invention to provide a surface mount oscillator having a cross-sectional H structure having a test electrode of a crystal resonator on a side surface and ensuring hermetic sealing.

  The present invention comprises a container body having concave portions on both main surfaces made of a laminated ceramic of a center layer composed of at least a first layer and a second layer, an upper frame layer having an opening, and a lower frame layer, which are flat. An outer peripheral portion of a crystal piece with an extraction electrode extending to a first crystal terminal provided on the bottom surface of one of the concave portions is fixed and hermetically sealed, and a first crystal terminal provided on the other bottom surface of the concave portion is provided. In a surface-mount crystal oscillator in which an IC terminal of an IC chip is fixed to a circuit terminal including two crystal terminals, the first crystal terminal is provided in the first and second layers of the central layer. The first crystal terminal is electrically connected to the second crystal terminal through a via hole, and the first crystal terminal is provided on the outer surface of the container body through the first via hole and the laminated surface of the first and second layers. Electrically connected to the test electrode of the crystal unit And it formed.

  With such a configuration, the first crystal terminal on the bottom surface of one of the recesses that hermetically encloses the crystal piece is the first via hole provided in the first layer of the central layer of the container body and the laminated surface of the first and second layers. And electrically connected to the inspection electrode of the crystal unit on the outer surface. Therefore, the through path can be lengthened without being limited by the width of the upper frame layer as compared with the case where the inspection electrode is electrically connected via the laminated surface of the upper frame layer and the central layer. Therefore, airtight sealing can be ensured.

  In addition, since the first via hole of the first layer electrically connected to the second crystal terminal on the bottom surface of the other concave portion is connected to the crystal inspection terminal in common, the design is facilitated without forming a new via hole.

  FIG. 1 is a diagram of a surface mount oscillator for explaining an embodiment of the present invention. FIG. 1 (a) is a sectional view and FIG. 1 (b) is a bottom view. In addition, the same number is attached | subjected to the same part as a prior art example, and the description is simplified or abbreviate | omitted.

  As described above, the surface-mount oscillator includes a container body 1 having a cross-section H structure including recesses on both main surfaces including a central layer 1a composed of a first layer A and a second layer B and an upper and lower frame layer 1 (bc); A pair of first crystal terminals 6 in one recess has an outer peripheral portion on both sides of one end portion where the extraction electrode extends and is fixed in a sealed manner, and a pair of second crystal terminals 8a on the bottom surface of the other recess. An IC chip 3 having an IC terminal fixed to a circuit terminal 8 is included.

  In this embodiment, a pair of first crystal terminals 6 on the bottom surface of one recess to which both ends of one end of the crystal piece 2 from which the extraction electrode extends are fixed are provided in the first layer A and the second layer B of the central layer 1a. Each pair of crank-shaped first and second via holes 9 (ab) extend to the bottom surface of the other recess and are directly connected to the pair of second crystal terminals 8a to which the crystal IC terminals of the IC chip 3 are fixed. . That is, the conventional crystal inspection terminal X (1, 2) is excluded from the bottom surface of the other recess.

  Then, from the pair of first via holes 9a of the first layer A, through the respective conductive paths 12 provided on the laminated surface of the first layer A and the second layer B, the crystal inspection terminals X ( Electrically connect to 1 and 2). In short, it branches from the first via hole 9a connected to the first crystal terminal 6 and is electrically connected to the second crystal terminal 8a and the crystal inspection terminal X (1, 2).

  The crystal inspection terminals X (1, 2) in this example are formed on one side surface of the container body 1 in the length direction and the width direction, which are on both sides of one end of the crystal piece 2 from which the extraction electrode extends. Then, two write terminals 10 (ab) for temperature compensation data are formed on the other side surface of the container body 1 in the length direction.

  With such a configuration, the first crystal terminal 6 is electrically connected to the crystal inspection terminal X (1, 2) on the outer surface through the first via hole and the laminated surface of the first layer A and the second layer B. . Therefore, the through path of the conductive path 12 can be made longer than in the case where the upper frame layer and the central layer 1a are connected via the laminated surface. Thereby, airtight leakage at the time of impact or the like is prevented, and airtight sealing is ensured.

  Further, here, the first and second crystal terminals 8a are branched from the pair of first via holes 9a in the first layer A and are connected to the crystal inspection terminals X (1, 2). Therefore, since the first via hole 9a is shared, no new via hole is formed. Therefore, the design can be facilitated.

(Other matters)
In the above embodiment, the first via hole 9a is formed in the lower surface direction of the first crystal terminal 6. However, for example, as shown in FIG. 2, the via hole is formed closer to the inner wall side on the other end side than the first crystal terminal 6. May be. In this case, since the conductive path 12 on the laminated surface of the first layer A and the second layer B has a longer distance to the crystal inspection electrode X (1, 2), the hermetic sealing can be further ensured. The surface mount oscillator is a temperature compensation type having the write terminal 10 (ab), but it is needless to say that it may be a non-temperature compensation type such as a clock oscillator.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure of the surface mount oscillator explaining one Embodiment of this invention, The figure (a) is sectional drawing, The figure (b) is a bottom view. It is sectional drawing of the surface mount oscillator explaining other embodiment of this invention. It is a figure of the surface mount oscillator explaining a prior art example, the figure (a) is a sectional view and the figure (b) is a bottom view. FIG. 5B is a cross-sectional view of a conventional surface mount crystal oscillator referred to by the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Container body, 2 Crystal piece, 3 IC chip, 4 Shield layer, 5 Mounting electrode, 6 1st crystal terminal, 7 Conductive adhesive, 8a 2nd crystal terminal, 8 Circuit terminal, 9 Via hole, 10 Write terminal, 11 Metal cover, 12 conductive path.

Claims (1)

  A container body having a concave portion on both main surfaces made of a laminated ceramic of a center layer composed of at least a first layer and a second layer and an upper frame layer having an opening and a lower frame layer, each of which is a flat plate, An outer peripheral portion of a crystal piece with an extraction electrode extending to a first crystal terminal provided on one recess bottom surface is fixed and hermetically sealed, and a second crystal terminal provided on the other recess bottom surface of the recess is provided. In a surface-mount crystal oscillator in which an IC terminal of an IC chip is fixed to a circuit terminal including the first crystal terminal, the first crystal terminal passes through first and second via holes provided in the first and second layers of the central layer. The first crystal terminal is electrically connected to the second crystal terminal, and the first crystal terminal is connected to the first via hole and the laminated surface of the first layer and the second layer. It is electrically connected to the inspection electrode Crystal oscillator for surface mounting to.

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