1. A semiconductor device comprising:
a semiconductor chip having a front surface over which a plurality of electrode pads is formed, and a back surface opposite to the front surface; and
a wiring board having a chip mounting surface over which the semiconductor chip is mounted, a mounting surface opposite to the chip mounting surface, a plurality of first pads arranged over the chip mounting surface and electrically connected with the electrode pads of the semiconductor chip, a plurality of lands arranged over the mounting surface in a matrix form and electrically connected with the first pads, a first conductor pattern arranged in a position of the mounting surface overlapped by the semiconductor chip in a thickness direction, and a first insulating layer covering the mounting surface,
wherein the first insulating layer has a plurality of first apertures formed such that a part of each of the lands is exposed, and a plurality of second apertures formed such that a plurality of portions of the first conductor pattern is exposed,
wherein the first conductor pattern has a plurality of first conductor apertures,
wherein a second insulating layer disposed over the first conductor pattern is exposed from the first conductor apertures, and
wherein outlines of the second apertures and the first conductor apertures overlap with each other, in a plan view, respectively.
2. The semiconductor device according to claim 1, wherein
if a virtual straight line passing through the center of a first region overlapped by the semiconductor chip in a thickness direction over the mounting surface and the center of each of the second apertures is defined as a first virtual straight line, the first conductor pattern is disposed at a first intersection adjacent to the center of the first region, of intersections of the first virtual straight line and each second aperture, and one of the first conductor apertures is disposed at a second intersection remote from the center of the first region, of the intersections.
3. The semiconductor device according to claim 2,
wherein the lands are formed integrally with lead wires disposed toward an inter-layer conductive path which electrically couples the chip mounting surface and the mounting surface,
wherein the lands are formed in a second region which differs from the first region, and
wherein the lands include first lands which are disposed integrally with the lead wires disposed over the mounting surface toward peripheries of the mounting surface and second lands which are disposed integrally with the lead wires disposed over the mounting surface toward the first region.
4. The semiconductor device according to claim 3, wherein half or more of outermost lands over the mounting surface are the first lands.
5. The semiconductor device according to claim 4,
wherein solder balls are joined to the lands in the first apertures, and
wherein solder balls are joined to the first conductor pattern in the second apertures.
6. The semiconductor device according to claim 5, wherein side surfaces of the lands are exposed from the first insulating layer through the first apertures.
7. The semiconductor device according to claim 6, wherein the first conductor pattern is formed in such a manner that the first conductor pattern covers peripheries of the first region.
8. The semiconductor device according to claim 7,
wherein the mounting surface has the second region disposed in such a manner that the second region surrounds the first region, and
wherein the innermost lands in the second region are formed integrally with the lead wires disposed toward the center of the first region.
9. The semiconductor device according to claim 1, wherein an area of each of the first conductor apertures is smaller than an area of each of the second apertures.
10. The semiconductor device according to claim 1, wherein each of the first conductor apertures is formed in such a manner that the first conductor aperture extends along an outline of the corresponding second aperture.
11. The semiconductor device according to claim 1, wherein each of the first conductor apertures overlaps one-fourth or more an outline of the corresponding second aperture.
12. The semiconductor device according to claim 1, wherein each of the first conductor apertures overlaps half or more an outline of the corresponding second aperture.
13. The semiconductor device according to claim 5,
wherein the lands have a plurality of exposed portions exposed from the first insulating layer in positions overlapping the first apertures,
wherein the first conductor pattern has a plurality of exposed portions exposed from the first insulating layer in positions overlapping the second apertures, and
wherein an exposed area of each of the first exposed portions is the same as an exposed area of each of the second exposed portions.
14. The semiconductor device according to claim 5,
wherein the lands have a plurality of exposed portions exposed from the first insulating layer in positions overlapping the first apertures,
wherein the first conductor pattern has a plurality of exposed portions exposed from the first insulating layer in positions overlapping the second apertures, and
wherein a shape of each of the first exposed portions is the same as a shape of each of the second exposed portions.
15. The semiconductor device according to claim 5,
wherein the lands have a plurality of first exposed portions exposed from the first insulating layer in positions overlapping the first apertures,
wherein the first conductor pattern has a plurality of second exposed portions exposed from the first insulating layer in positions overlapping the second apertures, and
wherein a metal film having higher wettability with respect to the solder balls than a metal member serving as a substrate is formed over exposed surfaces of the first and second exposed portions in such a manner that the metal film covers the metal member.
16. The semiconductor device according to claim 15,
wherein the lands and the metal member serving as a substrate of the first conductor pattern each comprise copper (Cu), and
wherein the metal film covering the metal member comprises nickel (Ni).
17. The semiconductor device according to claim 1,
wherein a second conductor pattern is disposed in a position overlapped by the semiconductor chip in a thickness direction over the chip mounting surface of the wiring board, and
wherein a plurality of inter-layer conductors connected with the second and first conductor patterns are formed between the second and first conductor patterns.
18. The semiconductor device according to claim 1,
wherein the first conductor pattern has a plurality of exposed portions exposed from the first insulating layer and a covered portion covered by the first insulating layer in positions overlapping the second apertures, and
wherein a first angle formed by an undersurface of the second insulating layer serving as an insulating underlayer over which the first conductor pattern is formed, and a side surface of the exposed portion is smaller than a second angle formed by the undersurface and a side surface of the covered portion.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A fuel injector control unit, comprising:
a memory unit, wherein said memory unit includes control parameters for controlling performance of a fuel injector, the control parameters reducing a pulse-width of a PWM signal when a power supply voltage of the fuel injector is greater than a predetermined rating voltage, and the control parameters increase the pulse-width of the PWM signal when a power supply voltage of the fuel injector is less than a predetermined rating voltage.
2. The fuel injector control unit according to claim 1, wherein the power supply voltage is supplied by a vehicle battery.
3. The fuel injector control unit according to claim 1, wherein the PWM signal is supplied by the fuel injector control unit.